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UBIFS: add new flash file system

Browse Source 
This is a new flash file system. See
http://www.linux-mtd.infradead.org/doc/ubifs.html

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
This commit is contained in:
Artem Bityutskiy 2008-07-14 19:08:37 +03:00
parent e56a99d5a4
commit 1e51764a3c
32 changed files with 32780 additions and 0 deletions
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/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Adrian Hunter
* Artem Bityutskiy (Битюцкий Артём)
*/
/*
* This file implements the budgeting sub-system which is responsible for UBIFS
* space management.
*
* Factors such as compression, wasted space at the ends of LEBs, space in other
* journal heads, the effect of updates on the index, and so on, make it
* impossible to accurately predict the amount of space needed. Consequently
* approximations are used.
*/
#include "ubifs.h"
#include <linux/writeback.h>
#include <asm/div64.h>
/*
* When pessimistic budget calculations say that there is no enough space,
* UBIFS starts writing back dirty inodes and pages, doing garbage collection,
* or committing. The below constants define maximum number of times UBIFS
* repeats the operations.
*/
#define MAX_SHRINK_RETRIES 8
#define MAX_GC_RETRIES 4
#define MAX_CMT_RETRIES 2
#define MAX_NOSPC_RETRIES 1
/*
* The below constant defines amount of dirty pages which should be written
* back at when trying to shrink the liability.
*/
#define NR_TO_WRITE 16
/**
* struct retries_info - information about re-tries while making free space.
* @prev_liability: previous liability
* @shrink_cnt: how many times the liability was shrinked
* @shrink_retries: count of liability shrink re-tries (increased when
* liability does not shrink)
* @try_gc: GC should be tried first
* @gc_retries: how many times GC was run
* @cmt_retries: how many times commit has been done
* @nospc_retries: how many times GC returned %-ENOSPC
*
* Since we consider budgeting to be the fast-path, and this structure has to
* be allocated on stack and zeroed out, we make it smaller using bit-fields.
*/
struct retries_info {
long long prev_liability;
unsigned int shrink_cnt;
unsigned int shrink_retries:5;
unsigned int try_gc:1;
unsigned int gc_retries:4;
unsigned int cmt_retries:3;
unsigned int nospc_retries:1;
};
/**
* shrink_liability - write-back some dirty pages/inodes.
* @c: UBIFS file-system description object
* @nr_to_write: how many dirty pages to write-back
*
* This function shrinks UBIFS liability by means of writing back some amount
* of dirty inodes and their pages. Returns the amount of pages which were
* written back. The returned value does not include dirty inodes which were
* synchronized.
*
* Note, this function synchronizes even VFS inodes which are locked
* (@i_mutex) by the caller of the budgeting function, because write-back does
* not touch @i_mutex.
*/
static int shrink_liability(struct ubifs_info *c, int nr_to_write)
{
int nr_written;
struct writeback_control wbc = {
.sync_mode = WB_SYNC_NONE,
.range_end = LLONG_MAX,
.nr_to_write = nr_to_write,
};
generic_sync_sb_inodes(c->vfs_sb, &wbc);
nr_written = nr_to_write - wbc.nr_to_write;
if (!nr_written) {
/*
* Re-try again but wait on pages/inodes which are being
* written-back concurrently (e.g., by pdflush).
*/
memset(&wbc, 0, sizeof(struct writeback_control));
wbc.sync_mode = WB_SYNC_ALL;
wbc.range_end = LLONG_MAX;
wbc.nr_to_write = nr_to_write;
generic_sync_sb_inodes(c->vfs_sb, &wbc);
nr_written = nr_to_write - wbc.nr_to_write;
}
dbg_budg("%d pages were written back", nr_written);
return nr_written;
}
/**
* run_gc - run garbage collector.
* @c: UBIFS file-system description object
*
* This function runs garbage collector to make some more free space. Returns
* zero if a free LEB has been produced, %-EAGAIN if commit is required, and a
* negative error code in case of failure.
*/
static int run_gc(struct ubifs_info *c)
{
int err, lnum;
/* Make some free space by garbage-collecting dirty space */
down_read(&c->commit_sem);
lnum = ubifs_garbage_collect(c, 1);
up_read(&c->commit_sem);
if (lnum < 0)
return lnum;
/* GC freed one LEB, return it to lprops */
dbg_budg("GC freed LEB %d", lnum);
err = ubifs_return_leb(c, lnum);
if (err)
return err;
return 0;
}
/**
* make_free_space - make more free space on the file-system.
* @c: UBIFS file-system description object
* @ri: information about previous invocations of this function
*
* This function is called when an operation cannot be budgeted because there
* is supposedly no free space. But in most cases there is some free space:
* o budgeting is pessimistic, so it always budgets more then it is actually
* needed, so shrinking the liability is one way to make free space - the
* cached data will take less space then it was budgeted for;
* o GC may turn some dark space into free space (budgeting treats dark space
* as not available);
* o commit may free some LEB, i.e., turn freeable LEBs into free LEBs.
*
* So this function tries to do the above. Returns %-EAGAIN if some free space
* was presumably made and the caller has to re-try budgeting the operation.
* Returns %-ENOSPC if it couldn't do more free space, and other negative error
* codes on failures.
*/
static int make_free_space(struct ubifs_info *c, struct retries_info *ri)
{
int err;
/*
* If we have some dirty pages and inodes (liability), try to write
* them back unless this was tried too many times without effect
* already.
*/
if (ri->shrink_retries < MAX_SHRINK_RETRIES && !ri->try_gc) {
long long liability;
spin_lock(&c->space_lock);
liability = c->budg_idx_growth + c->budg_data_growth +
c->budg_dd_growth;
spin_unlock(&c->space_lock);
if (ri->prev_liability >= liability) {
/* Liability does not shrink, next time try GC then */
ri->shrink_retries += 1;
if (ri->gc_retries < MAX_GC_RETRIES)
ri->try_gc = 1;
dbg_budg("liability did not shrink: retries %d of %d",
ri->shrink_retries, MAX_SHRINK_RETRIES);
}
dbg_budg("force write-back (count %d)", ri->shrink_cnt);
shrink_liability(c, NR_TO_WRITE + ri->shrink_cnt);
ri->prev_liability = liability;
ri->shrink_cnt += 1;
return -EAGAIN;
}
/*
* Try to run garbage collector unless it was already tried too many
* times.
*/
if (ri->gc_retries < MAX_GC_RETRIES) {
ri->gc_retries += 1;
dbg_budg("run GC, retries %d of %d",
ri->gc_retries, MAX_GC_RETRIES);
ri->try_gc = 0;
err = run_gc(c);
if (!err)
return -EAGAIN;
if (err == -EAGAIN) {
dbg_budg("GC asked to commit");
err = ubifs_run_commit(c);
if (err)
return err;
return -EAGAIN;
}
if (err != -ENOSPC)
return err;
/*
* GC could not make any progress. If this is the first time,
* then it makes sense to try to commit, because it might make
* some dirty space.
*/
dbg_budg("GC returned -ENOSPC, retries %d",
ri->nospc_retries);
if (ri->nospc_retries >= MAX_NOSPC_RETRIES)
return err;
ri->nospc_retries += 1;
}
/* Neither GC nor write-back helped, try to commit */
if (ri->cmt_retries < MAX_CMT_RETRIES) {
ri->cmt_retries += 1;
dbg_budg("run commit, retries %d of %d",
ri->cmt_retries, MAX_CMT_RETRIES);
err = ubifs_run_commit(c);
if (err)
return err;
return -EAGAIN;
}
return -ENOSPC;
}
/**
* ubifs_calc_min_idx_lebs - calculate amount of eraseblocks for the index.
* @c: UBIFS file-system description object
*
* This function calculates and returns the number of eraseblocks which should
* be kept for index usage.
*/
int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
{
int ret;
uint64_t idx_size;
idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx;
/* And make sure we have twice the index size of space reserved */
idx_size <<= 1;
/*
* We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes'
* pair, nor similarly the two variables for the new index size, so we
* have to do this costly 64-bit division on fast-path.
*/
if (do_div(idx_size, c->leb_size - c->max_idx_node_sz))
ret = idx_size + 1;
else
ret = idx_size;
/*
* The index head is not available for the in-the-gaps method, so add an
* extra LEB to compensate.
*/
ret += 1;
/*
* At present the index needs at least 2 LEBs: one for the index head
* and one for in-the-gaps method (which currently does not cater for
* the index head and so excludes it from consideration).
*/
if (ret < 2)
ret = 2;
return ret;
}
/**
* ubifs_calc_available - calculate available FS space.
* @c: UBIFS file-system description object
* @min_idx_lebs: minimum number of LEBs reserved for the index
*
* This function calculates and returns amount of FS space available for use.
*/
long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs)
{
int subtract_lebs;
long long available;
/*
* Force the amount available to the total size reported if the used
* space is zero.
*/
if (c->lst.total_used <= UBIFS_INO_NODE_SZ &&
c->budg_data_growth + c->budg_dd_growth == 0) {
/* Do the same calculation as for c->block_cnt */
available = c->main_lebs - 2;
available *= c->leb_size - c->dark_wm;
return available;
}
available = c->main_bytes - c->lst.total_used;
/*
* Now 'available' contains theoretically available flash space
* assuming there is no index, so we have to subtract the space which
* is reserved for the index.
*/
subtract_lebs = min_idx_lebs;
/* Take into account that GC reserves one LEB for its own needs */
subtract_lebs += 1;
/*
* The GC journal head LEB is not really accessible. And since
* different write types go to different heads, we may count only on
* one head's space.
*/
subtract_lebs += c->jhead_cnt - 1;
/* We also reserve one LEB for deletions, which bypass budgeting */
subtract_lebs += 1;
available -= (long long)subtract_lebs * c->leb_size;
/* Subtract the dead space which is not available for use */
available -= c->lst.total_dead;
/*
* Subtract dark space, which might or might not be usable - it depends
* on the data which we have on the media and which will be written. If
* this is a lot of uncompressed or not-compressible data, the dark
* space cannot be used.
*/
available -= c->lst.total_dark;
/*
* However, there is more dark space. The index may be bigger than
* @min_idx_lebs. Those extra LEBs are assumed to be available, but
* their dark space is not included in total_dark, so it is subtracted
* here.
*/
if (c->lst.idx_lebs > min_idx_lebs) {
subtract_lebs = c->lst.idx_lebs - min_idx_lebs;
available -= subtract_lebs * c->dark_wm;
}
/* The calculations are rough and may end up with a negative number */
return available > 0 ? available : 0;
}
/**
* can_use_rp - check whether the user is allowed to use reserved pool.
* @c: UBIFS file-system description object
*
* UBIFS has so-called "reserved pool" which is flash space reserved
* for the superuser and for uses whose UID/GID is recorded in UBIFS superblock.
* This function checks whether current user is allowed to use reserved pool.
* Returns %1 current user is allowed to use reserved pool and %0 otherwise.
*/
static int can_use_rp(struct ubifs_info *c)
{
if (current->fsuid == c->rp_uid || capable(CAP_SYS_RESOURCE) ||
(c->rp_gid != 0 && in_group_p(c->rp_gid)))
return 1;
return 0;
}
/**
* do_budget_space - reserve flash space for index and data growth.
* @c: UBIFS file-system description object
*
* This function makes sure UBIFS has enough free eraseblocks for index growth
* and data.
*
* When budgeting index space, UBIFS reserves twice as more LEBs as the index
* would take if it was consolidated and written to the flash. This guarantees
* that the "in-the-gaps" commit method always succeeds and UBIFS will always
* be able to commit dirty index. So this function basically adds amount of
* budgeted index space to the size of the current index, multiplies this by 2,
* and makes sure this does not exceed the amount of free eraseblocks.
*
* Notes about @c->min_idx_lebs and @c->lst.idx_lebs variables:
* o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might
* be large, because UBIFS does not do any index consolidation as long as
* there is free space. IOW, the index may take a lot of LEBs, but the LEBs
* will contain a lot of dirt.
* o @c->min_idx_lebs is the the index presumably takes. IOW, the index may be
* consolidated to take up to @c->min_idx_lebs LEBs.
*
* This function returns zero in case of success, and %-ENOSPC in case of
* failure.
*/
static int do_budget_space(struct ubifs_info *c)
{
long long outstanding, available;
int lebs, rsvd_idx_lebs, min_idx_lebs;
/* First budget index space */
min_idx_lebs = ubifs_calc_min_idx_lebs(c);
/* Now 'min_idx_lebs' contains number of LEBs to reserve */
if (min_idx_lebs > c->lst.idx_lebs)
rsvd_idx_lebs = min_idx_lebs - c->lst.idx_lebs;
else
rsvd_idx_lebs = 0;
/*
* The number of LEBs that are available to be used by the index is:
*
* @c->lst.empty_lebs + @c->freeable_cnt + @c->idx_gc_cnt -
* @c->lst.taken_empty_lebs
*
* @empty_lebs are available because they are empty. @freeable_cnt are
* available because they contain only free and dirty space and the
* index allocation always occurs after wbufs are synch'ed.
* @idx_gc_cnt are available because they are index LEBs that have been
* garbage collected (including trivial GC) and are awaiting the commit
* before they can be unmapped - note that the in-the-gaps method will
* grab these if it needs them. @taken_empty_lebs are empty_lebs that
* have already been allocated for some purpose (also includes those
* LEBs on the @idx_gc list).
*
* Note, @taken_empty_lebs may temporarily be higher by one because of
* the way we serialize LEB allocations and budgeting. See a comment in
* 'ubifs_find_free_space()'.
*/
lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
c->lst.taken_empty_lebs;
if (unlikely(rsvd_idx_lebs > lebs)) {
dbg_budg("out of indexing space: min_idx_lebs %d (old %d), "
"rsvd_idx_lebs %d", min_idx_lebs, c->min_idx_lebs,
rsvd_idx_lebs);
return -ENOSPC;
}
available = ubifs_calc_available(c, min_idx_lebs);
outstanding = c->budg_data_growth + c->budg_dd_growth;
if (unlikely(available < outstanding)) {
dbg_budg("out of data space: available %lld, outstanding %lld",
available, outstanding);
return -ENOSPC;
}
if (available - outstanding <= c->rp_size && !can_use_rp(c))
return -ENOSPC;
c->min_idx_lebs = min_idx_lebs;
return 0;
}
/**
* calc_idx_growth - calculate approximate index growth from budgeting request.
* @c: UBIFS file-system description object
* @req: budgeting request
*
* For now we assume each new node adds one znode. But this is rather poor
* approximation, though.
*/
static int calc_idx_growth(const struct ubifs_info *c,
const struct ubifs_budget_req *req)
{
int znodes;
znodes = req->new_ino + (req->new_page << UBIFS_BLOCKS_PER_PAGE_SHIFT) +
req->new_dent;
return znodes * c->max_idx_node_sz;
}
/**
* calc_data_growth - calculate approximate amount of new data from budgeting
* request.
* @c: UBIFS file-system description object
* @req: budgeting request
*/
static int calc_data_growth(const struct ubifs_info *c,
const struct ubifs_budget_req *req)
{
int data_growth;
data_growth = req->new_ino ? c->inode_budget : 0;
if (req->new_page)
data_growth += c->page_budget;
if (req->new_dent)
data_growth += c->dent_budget;
data_growth += req->new_ino_d;
return data_growth;
}
/**
* calc_dd_growth - calculate approximate amount of data which makes other data
* dirty from budgeting request.
* @c: UBIFS file-system description object
* @req: budgeting request
*/
static int calc_dd_growth(const struct ubifs_info *c,
const struct ubifs_budget_req *req)
{
int dd_growth;
dd_growth = req->dirtied_page ? c->page_budget : 0;
if (req->dirtied_ino)
dd_growth += c->inode_budget << (req->dirtied_ino - 1);
if (req->mod_dent)
dd_growth += c->dent_budget;
dd_growth += req->dirtied_ino_d;
return dd_growth;
}
/**
* ubifs_budget_space - ensure there is enough space to complete an operation.
* @c: UBIFS file-system description object
* @req: budget request
*
* This function allocates budget for an operation. It uses pessimistic
* approximation of how much flash space the operation needs. The goal of this
* function is to make sure UBIFS always has flash space to flush all dirty
* pages, dirty inodes, and dirty znodes (liability). This function may force
* commit, garbage-collection or write-back. Returns zero in case of success,
* %-ENOSPC if there is no free space and other negative error codes in case of
* failures.
*/
int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req)
{
int uninitialized_var(cmt_retries), uninitialized_var(wb_retries);
int err, idx_growth, data_growth, dd_growth;
struct retries_info ri;
ubifs_assert(req->dirtied_ino <= 4);
ubifs_assert(req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4);
data_growth = calc_data_growth(c, req);
dd_growth = calc_dd_growth(c, req);
if (!data_growth && !dd_growth)
return 0;
idx_growth = calc_idx_growth(c, req);
memset(&ri, 0, sizeof(struct retries_info));
again:
spin_lock(&c->space_lock);
ubifs_assert(c->budg_idx_growth >= 0);
ubifs_assert(c->budg_data_growth >= 0);
ubifs_assert(c->budg_dd_growth >= 0);
if (unlikely(c->nospace) && (c->nospace_rp || !can_use_rp(c))) {
dbg_budg("no space");
spin_unlock(&c->space_lock);
return -ENOSPC;
}
c->budg_idx_growth += idx_growth;
c->budg_data_growth += data_growth;
c->budg_dd_growth += dd_growth;
err = do_budget_space(c);
if (likely(!err)) {
req->idx_growth = idx_growth;
req->data_growth = data_growth;
req->dd_growth = dd_growth;
spin_unlock(&c->space_lock);
return 0;
}
/* Restore the old values */
c->budg_idx_growth -= idx_growth;
c->budg_data_growth -= data_growth;
c->budg_dd_growth -= dd_growth;
spin_unlock(&c->space_lock);
if (req->fast) {
dbg_budg("no space for fast budgeting");
return err;
}
err = make_free_space(c, &ri);
if (err == -EAGAIN) {
dbg_budg("try again");
cond_resched();
goto again;
} else if (err == -ENOSPC) {
dbg_budg("FS is full, -ENOSPC");
c->nospace = 1;
if (can_use_rp(c) || c->rp_size == 0)
c->nospace_rp = 1;
smp_wmb();
} else
ubifs_err("cannot budget space, error %d", err);
return err;
}
/**
* ubifs_release_budget - release budgeted free space.
* @c: UBIFS file-system description object
* @req: budget request
*
* This function releases the space budgeted by 'ubifs_budget_space()'. Note,
* since the index changes (which were budgeted for in @req->idx_growth) will
* only be written to the media on commit, this function moves the index budget
* from @c->budg_idx_growth to @c->budg_uncommitted_idx. The latter will be
* zeroed by the commit operation.
*/
void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req)
{
ubifs_assert(req->dirtied_ino <= 4);
ubifs_assert(req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4);
if (!req->recalculate) {
ubifs_assert(req->idx_growth >= 0);
ubifs_assert(req->data_growth >= 0);
ubifs_assert(req->dd_growth >= 0);
}
if (req->recalculate) {
req->data_growth = calc_data_growth(c, req);
req->dd_growth = calc_dd_growth(c, req);
req->idx_growth = calc_idx_growth(c, req);
}
if (!req->data_growth && !req->dd_growth)
return;
c->nospace = c->nospace_rp = 0;
smp_wmb();
spin_lock(&c->space_lock);
c->budg_idx_growth -= req->idx_growth;
c->budg_uncommitted_idx += req->idx_growth;
c->budg_data_growth -= req->data_growth;
c->budg_dd_growth -= req->dd_growth;
c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
ubifs_assert(c->budg_idx_growth >= 0);
ubifs_assert(c->budg_data_growth >= 0);
ubifs_assert(c->min_idx_lebs < c->main_lebs);
spin_unlock(&c->space_lock);
}
/**
* ubifs_convert_page_budget - convert budget of a new page.
* @c: UBIFS file-system description object
*
* This function converts budget which was allocated for a new page of data to
* the budget of changing an existing page of data. The latter is smaller then
* the former, so this function only does simple re-calculation and does not
* involve any write-back.
*/
void ubifs_convert_page_budget(struct ubifs_info *c)
{
spin_lock(&c->space_lock);
/* Release the index growth reservation */
c->budg_idx_growth -= c->max_idx_node_sz << UBIFS_BLOCKS_PER_PAGE_SHIFT;
/* Release the data growth reservation */
c->budg_data_growth -= c->page_budget;
/* Increase the dirty data growth reservation instead */
c->budg_dd_growth += c->page_budget;
/* And re-calculate the indexing space reservation */
c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
spin_unlock(&c->space_lock);
}
/**
* ubifs_release_dirty_inode_budget - release dirty inode budget.
* @c: UBIFS file-system description object
* @ui: UBIFS inode to release the budget for
*
* This function releases budget corresponding to a dirty inode. It is usually
* called when after the inode has been written to the media and marked as
* clean.
*/
void ubifs_release_dirty_inode_budget(struct ubifs_info *c,
struct ubifs_inode *ui)
{
struct ubifs_budget_req req = {.dd_growth = c->inode_budget,
.dirtied_ino_d = ui->data_len};
ubifs_release_budget(c, &req);
}
/**
* ubifs_budg_get_free_space - return amount of free space.
* @c: UBIFS file-system description object
*
* This function returns amount of free space on the file-system.
*/
long long ubifs_budg_get_free_space(struct ubifs_info *c)
{
int min_idx_lebs, rsvd_idx_lebs;
long long available, outstanding, free;
/* Do exactly the same calculations as in 'do_budget_space()' */
spin_lock(&c->space_lock);
min_idx_lebs = ubifs_calc_min_idx_lebs(c);
if (min_idx_lebs > c->lst.idx_lebs)
rsvd_idx_lebs = min_idx_lebs - c->lst.idx_lebs;
else
rsvd_idx_lebs = 0;
if (rsvd_idx_lebs > c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt
- c->lst.taken_empty_lebs) {
spin_unlock(&c->space_lock);
return 0;
}
available = ubifs_calc_available(c, min_idx_lebs);
outstanding = c->budg_data_growth + c->budg_dd_growth;
c->min_idx_lebs = min_idx_lebs;
spin_unlock(&c->space_lock);
if (available > outstanding)
free = ubifs_reported_space(c, available - outstanding);
else
free = 0;
return free;
}

677
fs/ubifs/commit.c Normal file
View File

@ -0,0 +1,677 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Adrian Hunter
* Artem Bityutskiy (Битюцкий Артём)
*/
/*
* This file implements functions that manage the running of the commit process.
* Each affected module has its own functions to accomplish their part in the
* commit and those functions are called here.
*
* The commit is the process whereby all updates to the index and LEB properties
* are written out together and the journal becomes empty. This keeps the
* file system consistent - at all times the state can be recreated by reading
* the index and LEB properties and then replaying the journal.
*
* The commit is split into two parts named "commit start" and "commit end".
* During commit start, the commit process has exclusive access to the journal
* by holding the commit semaphore down for writing. As few I/O operations as
* possible are performed during commit start, instead the nodes that are to be
* written are merely identified. During commit end, the commit semaphore is no
* longer held and the journal is again in operation, allowing users to continue
* to use the file system while the bulk of the commit I/O is performed. The
* purpose of this two-step approach is to prevent the commit from causing any
* latency blips. Note that in any case, the commit does not prevent lookups
* (as permitted by the TNC mutex), or access to VFS data structures e.g. page
* cache.
*/
#include <linux/freezer.h>
#include <linux/kthread.h>
#include "ubifs.h"
/**
* do_commit - commit the journal.
* @c: UBIFS file-system description object
*
* This function implements UBIFS commit. It has to be called with commit lock
* locked. Returns zero in case of success and a negative error code in case of
* failure.
*/
static int do_commit(struct ubifs_info *c)
{
int err, new_ltail_lnum, old_ltail_lnum, i;
struct ubifs_zbranch zroot;
struct ubifs_lp_stats lst;
dbg_cmt("start");
if (c->ro_media) {
err = -EROFS;
goto out_up;
}
/* Sync all write buffers (necessary for recovery) */
for (i = 0; i < c->jhead_cnt; i++) {
err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
if (err)
goto out_up;
}
err = ubifs_gc_start_commit(c);
if (err)
goto out_up;
err = dbg_check_lprops(c);
if (err)
goto out_up;
err = ubifs_log_start_commit(c, &new_ltail_lnum);
if (err)
goto out_up;
err = ubifs_tnc_start_commit(c, &zroot);
if (err)
goto out_up;
err = ubifs_lpt_start_commit(c);
if (err)
goto out_up;
err = ubifs_orphan_start_commit(c);
if (err)
goto out_up;
ubifs_get_lp_stats(c, &lst);
up_write(&c->commit_sem);
err = ubifs_tnc_end_commit(c);
if (err)
goto out;
err = ubifs_lpt_end_commit(c);
if (err)
goto out;
err = ubifs_orphan_end_commit(c);
if (err)
goto out;
old_ltail_lnum = c->ltail_lnum;
err = ubifs_log_end_commit(c, new_ltail_lnum);
if (err)
goto out;
err = dbg_check_old_index(c, &zroot);
if (err)
goto out;
mutex_lock(&c->mst_mutex);
c->mst_node->cmt_no = cpu_to_le64(++c->cmt_no);
c->mst_node->log_lnum = cpu_to_le32(new_ltail_lnum);
c->mst_node->root_lnum = cpu_to_le32(zroot.lnum);
c->mst_node->root_offs = cpu_to_le32(zroot.offs);
c->mst_node->root_len = cpu_to_le32(zroot.len);
c->mst_node->ihead_lnum = cpu_to_le32(c->ihead_lnum);
c->mst_node->ihead_offs = cpu_to_le32(c->ihead_offs);
c->mst_node->index_size = cpu_to_le64(c->old_idx_sz);
c->mst_node->lpt_lnum = cpu_to_le32(c->lpt_lnum);
c->mst_node->lpt_offs = cpu_to_le32(c->lpt_offs);
c->mst_node->nhead_lnum = cpu_to_le32(c->nhead_lnum);
c->mst_node->nhead_offs = cpu_to_le32(c->nhead_offs);
c->mst_node->ltab_lnum = cpu_to_le32(c->ltab_lnum);
c->mst_node->ltab_offs = cpu_to_le32(c->ltab_offs);
c->mst_node->lsave_lnum = cpu_to_le32(c->lsave_lnum);
c->mst_node->lsave_offs = cpu_to_le32(c->lsave_offs);
c->mst_node->lscan_lnum = cpu_to_le32(c->lscan_lnum);
c->mst_node->empty_lebs = cpu_to_le32(lst.empty_lebs);
c->mst_node->idx_lebs = cpu_to_le32(lst.idx_lebs);
c->mst_node->total_free = cpu_to_le64(lst.total_free);
c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty);
c->mst_node->total_used = cpu_to_le64(lst.total_used);
c->mst_node->total_dead = cpu_to_le64(lst.total_dead);
c->mst_node->total_dark = cpu_to_le64(lst.total_dark);
if (c->no_orphs)
c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
else
c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS);
err = ubifs_write_master(c);
mutex_unlock(&c->mst_mutex);
if (err)
goto out;
err = ubifs_log_post_commit(c, old_ltail_lnum);
if (err)
goto out;
err = ubifs_gc_end_commit(c);
if (err)
goto out;
err = ubifs_lpt_post_commit(c);
if (err)
goto out;
spin_lock(&c->cs_lock);
c->cmt_state = COMMIT_RESTING;
wake_up(&c->cmt_wq);
dbg_cmt("commit end");
spin_unlock(&c->cs_lock);
return 0;
out_up:
up_write(&c->commit_sem);
out:
ubifs_err("commit failed, error %d", err);
spin_lock(&c->cs_lock);
c->cmt_state = COMMIT_BROKEN;
wake_up(&c->cmt_wq);
spin_unlock(&c->cs_lock);
ubifs_ro_mode(c, err);
return err;
}
/**
* run_bg_commit - run background commit if it is needed.
* @c: UBIFS file-system description object
*
* This function runs background commit if it is needed. Returns zero in case
* of success and a negative error code in case of failure.
*/
static int run_bg_commit(struct ubifs_info *c)
{
spin_lock(&c->cs_lock);
/*
* Run background commit only if background commit was requested or if
* commit is required.
*/
if (c->cmt_state != COMMIT_BACKGROUND &&
c->cmt_state != COMMIT_REQUIRED)
goto out;
spin_unlock(&c->cs_lock);
down_write(&c->commit_sem);
spin_lock(&c->cs_lock);
if (c->cmt_state == COMMIT_REQUIRED)
c->cmt_state = COMMIT_RUNNING_REQUIRED;
else if (c->cmt_state == COMMIT_BACKGROUND)
c->cmt_state = COMMIT_RUNNING_BACKGROUND;
else
goto out_cmt_unlock;
spin_unlock(&c->cs_lock);
return do_commit(c);
out_cmt_unlock:
up_write(&c->commit_sem);
out:
spin_unlock(&c->cs_lock);
return 0;
}
/**
* ubifs_bg_thread - UBIFS background thread function.
* @info: points to the file-system description object
*
* This function implements various file-system background activities:
* o when a write-buffer timer expires it synchronizes the appropriate
* write-buffer;
* o when the journal is about to be full, it starts in-advance commit.
*
* Note, other stuff like background garbage collection may be added here in
* future.
*/
int ubifs_bg_thread(void *info)
{
int err;
struct ubifs_info *c = info;
ubifs_msg("background thread \"%s\" started, PID %d",
c->bgt_name, current->pid);
set_freezable();
while (1) {
if (kthread_should_stop())
break;
if (try_to_freeze())
continue;
set_current_state(TASK_INTERRUPTIBLE);
/* Check if there is something to do */
if (!c->need_bgt) {
/*
* Nothing prevents us from going sleep now and
* be never woken up and block the task which
* could wait in 'kthread_stop()' forever.
*/
if (kthread_should_stop())
break;
schedule();
continue;
} else
__set_current_state(TASK_RUNNING);
c->need_bgt = 0;
err = ubifs_bg_wbufs_sync(c);
if (err)
ubifs_ro_mode(c, err);
run_bg_commit(c);
cond_resched();
}
dbg_msg("background thread \"%s\" stops", c->bgt_name);
return 0;
}
/**
* ubifs_commit_required - set commit state to "required".
* @c: UBIFS file-system description object
*
* This function is called if a commit is required but cannot be done from the
* calling function, so it is just flagged instead.
*/
void ubifs_commit_required(struct ubifs_info *c)
{
spin_lock(&c->cs_lock);
switch (c->cmt_state) {
case COMMIT_RESTING:
case COMMIT_BACKGROUND:
dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
dbg_cstate(COMMIT_REQUIRED));
c->cmt_state = COMMIT_REQUIRED;
break;
case COMMIT_RUNNING_BACKGROUND:
dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
dbg_cstate(COMMIT_RUNNING_REQUIRED));
c->cmt_state = COMMIT_RUNNING_REQUIRED;
break;
case COMMIT_REQUIRED:
case COMMIT_RUNNING_REQUIRED:
case COMMIT_BROKEN:
break;
}
spin_unlock(&c->cs_lock);
}
/**
* ubifs_request_bg_commit - notify the background thread to do a commit.
* @c: UBIFS file-system description object
*
* This function is called if the journal is full enough to make a commit
* worthwhile, so background thread is kicked to start it.
*/
void ubifs_request_bg_commit(struct ubifs_info *c)
{
spin_lock(&c->cs_lock);
if (c->cmt_state == COMMIT_RESTING) {
dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
dbg_cstate(COMMIT_BACKGROUND));
c->cmt_state = COMMIT_BACKGROUND;
spin_unlock(&c->cs_lock);
ubifs_wake_up_bgt(c);
} else
spin_unlock(&c->cs_lock);
}
/**
* wait_for_commit - wait for commit.
* @c: UBIFS file-system description object
*
* This function sleeps until the commit operation is no longer running.
*/
static int wait_for_commit(struct ubifs_info *c)
{
dbg_cmt("pid %d goes sleep", current->pid);
/*
* The following sleeps if the condition is false, and will be woken
* when the commit ends. It is possible, although very unlikely, that we
* will wake up and see the subsequent commit running, rather than the
* one we were waiting for, and go back to sleep. However, we will be
* woken again, so there is no danger of sleeping forever.
*/
wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND &&
c->cmt_state != COMMIT_RUNNING_REQUIRED);
dbg_cmt("commit finished, pid %d woke up", current->pid);
return 0;
}
/**
* ubifs_run_commit - run or wait for commit.
* @c: UBIFS file-system description object
*
* This function runs commit and returns zero in case of success and a negative
* error code in case of failure.
*/
int ubifs_run_commit(struct ubifs_info *c)
{
int err = 0;
spin_lock(&c->cs_lock);
if (c->cmt_state == COMMIT_BROKEN) {
err = -EINVAL;
goto out;
}
if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
/*
* We set the commit state to 'running required' to indicate
* that we want it to complete as quickly as possible.
*/
c->cmt_state = COMMIT_RUNNING_REQUIRED;
if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
spin_unlock(&c->cs_lock);
return wait_for_commit(c);
}
spin_unlock(&c->cs_lock);
/* Ok, the commit is indeed needed */
down_write(&c->commit_sem);
spin_lock(&c->cs_lock);
/*
* Since we unlocked 'c->cs_lock', the state may have changed, so
* re-check it.
*/
if (c->cmt_state == COMMIT_BROKEN) {
err = -EINVAL;
goto out_cmt_unlock;
}
if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
c->cmt_state = COMMIT_RUNNING_REQUIRED;
if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
up_write(&c->commit_sem);
spin_unlock(&c->cs_lock);
return wait_for_commit(c);
}
c->cmt_state = COMMIT_RUNNING_REQUIRED;
spin_unlock(&c->cs_lock);
err = do_commit(c);
return err;
out_cmt_unlock:
up_write(&c->commit_sem);
out:
spin_unlock(&c->cs_lock);
return err;
}
/**
* ubifs_gc_should_commit - determine if it is time for GC to run commit.
* @c: UBIFS file-system description object
*
* This function is called by garbage collection to determine if commit should
* be run. If commit state is @COMMIT_BACKGROUND, which means that the journal
* is full enough to start commit, this function returns true. It is not
* absolutely necessary to commit yet, but it feels like this should be better
* then to keep doing GC. This function returns %1 if GC has to initiate commit
* and %0 if not.
*/
int ubifs_gc_should_commit(struct ubifs_info *c)
{
int ret = 0;
spin_lock(&c->cs_lock);
if (c->cmt_state == COMMIT_BACKGROUND) {
dbg_cmt("commit required now");
c->cmt_state = COMMIT_REQUIRED;
} else
dbg_cmt("commit not requested");
if (c->cmt_state == COMMIT_REQUIRED)
ret = 1;
spin_unlock(&c->cs_lock);
return ret;
}
#ifdef CONFIG_UBIFS_FS_DEBUG
/**
* struct idx_node - hold index nodes during index tree traversal.
* @list: list
* @iip: index in parent (slot number of this indexing node in the parent
* indexing node)
* @upper_key: all keys in this indexing node have to be less or equivalent to
* this key
* @idx: index node (8-byte aligned because all node structures must be 8-byte
* aligned)
*/
struct idx_node {
struct list_head list;
int iip;
union ubifs_key upper_key;
struct ubifs_idx_node idx __attribute__((aligned(8)));
};
/**
* dbg_old_index_check_init - get information for the next old index check.
* @c: UBIFS file-system description object
* @zroot: root of the index
*
* This function records information about the index that will be needed for the
* next old index check i.e. 'dbg_check_old_index()'.
*
* This function returns %0 on success and a negative error code on failure.
*/
int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot)
{
struct ubifs_idx_node *idx;
int lnum, offs, len, err = 0;
c->old_zroot = *zroot;
lnum = c->old_zroot.lnum;
offs = c->old_zroot.offs;
len = c->old_zroot.len;
idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
if (!idx)
return -ENOMEM;
err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
if (err)
goto out;
c->old_zroot_level = le16_to_cpu(idx->level);
c->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum);
out:
kfree(idx);
return err;
}
/**
* dbg_check_old_index - check the old copy of the index.
* @c: UBIFS file-system description object
* @zroot: root of the new index
*
* In order to be able to recover from an unclean unmount, a complete copy of
* the index must exist on flash. This is the "old" index. The commit process
* must write the "new" index to flash without overwriting or destroying any
* part of the old index. This function is run at commit end in order to check
* that the old index does indeed exist completely intact.
*
* This function returns %0 on success and a negative error code on failure.
*/
int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
{
int lnum, offs, len, err = 0, uninitialized_var(last_level), child_cnt;
int first = 1, iip;
union ubifs_key lower_key, upper_key, l_key, u_key;
unsigned long long uninitialized_var(last_sqnum);
struct ubifs_idx_node *idx;
struct list_head list;
struct idx_node *i;
size_t sz;
if (!(ubifs_chk_flags & UBIFS_CHK_OLD_IDX))
goto out;
INIT_LIST_HEAD(&list);
sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, c->fanout) -
UBIFS_IDX_NODE_SZ;
/* Start at the old zroot */
lnum = c->old_zroot.lnum;
offs = c->old_zroot.offs;
len = c->old_zroot.len;
iip = 0;
/*
* Traverse the index tree preorder depth-first i.e. do a node and then
* its subtrees from left to right.
*/
while (1) {
struct ubifs_branch *br;
/* Get the next index node */
i = kmalloc(sz, GFP_NOFS);
if (!i) {
err = -ENOMEM;
goto out_free;
}
i->iip = iip;
/* Keep the index nodes on our path in a linked list */
list_add_tail(&i->list, &list);
/* Read the index node */
idx = &i->idx;
err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
if (err)
goto out_free;
/* Validate index node */
child_cnt = le16_to_cpu(idx->child_cnt);
if (child_cnt < 1 || child_cnt > c->fanout) {
err = 1;
goto out_dump;
}
if (first) {
first = 0;
/* Check root level and sqnum */
if (le16_to_cpu(idx->level) != c->old_zroot_level) {
err = 2;
goto out_dump;
}
if (le64_to_cpu(idx->ch.sqnum) != c->old_zroot_sqnum) {
err = 3;
goto out_dump;
}
/* Set last values as though root had a parent */
last_level = le16_to_cpu(idx->level) + 1;
last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1;
key_read(c, ubifs_idx_key(c, idx), &lower_key);
highest_ino_key(c, &upper_key, INUM_WATERMARK);
}
key_copy(c, &upper_key, &i->upper_key);
if (le16_to_cpu(idx->level) != last_level - 1) {
err = 3;
goto out_dump;
}
/*
* The index is always written bottom up hence a child's sqnum
* is always less than the parents.
*/
if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) {
err = 4;
goto out_dump;
}
/* Check key range */
key_read(c, ubifs_idx_key(c, idx), &l_key);
br = ubifs_idx_branch(c, idx, child_cnt - 1);
key_read(c, &br->key, &u_key);
if (keys_cmp(c, &lower_key, &l_key) > 0) {
err = 5;
goto out_dump;
}
if (keys_cmp(c, &upper_key, &u_key) < 0) {
err = 6;
goto out_dump;
}
if (keys_cmp(c, &upper_key, &u_key) == 0)
if (!is_hash_key(c, &u_key)) {
err = 7;
goto out_dump;
}
/* Go to next index node */
if (le16_to_cpu(idx->level) == 0) {
/* At the bottom, so go up until can go right */
while (1) {
/* Drop the bottom of the list */
list_del(&i->list);
kfree(i);
/* No more list means we are done */
if (list_empty(&list))
goto out;
/* Look at the new bottom */
i = list_entry(list.prev, struct idx_node,
list);
idx = &i->idx;
/* Can we go right */
if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
iip = iip + 1;
break;
} else
/* Nope, so go up again */
iip = i->iip;
}
} else
/* Go down left */
iip = 0;
/*
* We have the parent in 'idx' and now we set up for reading the
* child pointed to by slot 'iip'.
*/
last_level = le16_to_cpu(idx->level);
last_sqnum = le64_to_cpu(idx->ch.sqnum);
br = ubifs_idx_branch(c, idx, iip);
lnum = le32_to_cpu(br->lnum);
offs = le32_to_cpu(br->offs);
len = le32_to_cpu(br->len);
key_read(c, &br->key, &lower_key);
if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
br = ubifs_idx_branch(c, idx, iip + 1);
key_read(c, &br->key, &upper_key);
} else
key_copy(c, &i->upper_key, &upper_key);
}
out:
err = dbg_old_index_check_init(c, zroot);
if (err)
goto out_free;
return 0;
out_dump:
dbg_err("dumping index node (iip=%d)", i->iip);
dbg_dump_node(c, idx);
list_del(&i->list);
kfree(i);
if (!list_empty(&list)) {
i = list_entry(list.prev, struct idx_node, list);
dbg_err("dumping parent index node");
dbg_dump_node(c, &i->idx);
}
out_free:
while (!list_empty(&list)) {
i = list_entry(list.next, struct idx_node, list);
list_del(&i->list);
kfree(i);
}
ubifs_err("failed, error %d", err);
if (err > 0)
err = -EINVAL;
return err;
}
#endif /* CONFIG_UBIFS_FS_DEBUG */

253
fs/ubifs/compress.c Normal file
View File

@ -0,0 +1,253 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
* Copyright (C) 2006, 2007 University of Szeged, Hungary
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Adrian Hunter
* Artem Bityutskiy (Битюцкий Артём)
* Zoltan Sogor
*/
/*
* This file provides a single place to access to compression and
* decompression.
*/
#include <linux/crypto.h>
#include "ubifs.h"
/* Fake description object for the "none" compressor */
static struct ubifs_compressor none_compr = {
.compr_type = UBIFS_COMPR_NONE,
.name = "no compression",
.capi_name = "",
};
#ifdef CONFIG_UBIFS_FS_LZO
static DEFINE_MUTEX(lzo_mutex);
static struct ubifs_compressor lzo_compr = {
.compr_type = UBIFS_COMPR_LZO,
.comp_mutex = &lzo_mutex,
.name = "LZO",
.capi_name = "lzo",
};
#else
static struct ubifs_compressor lzo_compr = {
.compr_type = UBIFS_COMPR_LZO,
.name = "LZO",
};
#endif
#ifdef CONFIG_UBIFS_FS_ZLIB
static DEFINE_MUTEX(deflate_mutex);
static DEFINE_MUTEX(inflate_mutex);
static struct ubifs_compressor zlib_compr = {
.compr_type = UBIFS_COMPR_ZLIB,
.comp_mutex = &deflate_mutex,
.decomp_mutex = &inflate_mutex,
.name = "zlib",
.capi_name = "deflate",
};
#else
static struct ubifs_compressor zlib_compr = {
.compr_type = UBIFS_COMPR_ZLIB,
.name = "zlib",
};
#endif
/* All UBIFS compressors */
struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];
/**
* ubifs_compress - compress data.
* @in_buf: data to compress
* @in_len: length of the data to compress
* @out_buf: output buffer where compressed data should be stored
* @out_len: output buffer length is returned here
* @compr_type: type of compression to use on enter, actually used compression
* type on exit
*
* This function compresses input buffer @in_buf of length @in_len and stores
* the result in the output buffer @out_buf and the resulting length in
* @out_len. If the input buffer does not compress, it is just copied to the
* @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if
* compression error occurred.
*
* Note, if the input buffer was not compressed, it is copied to the output
* buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
*
* This functions returns %0 on success or a negative error code on failure.
*/
void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len,
int *compr_type)
{
int err;
struct ubifs_compressor *compr = ubifs_compressors[*compr_type];
if (*compr_type == UBIFS_COMPR_NONE)
goto no_compr;
/* If the input data is small, do not even try to compress it */
if (in_len < UBIFS_MIN_COMPR_LEN)
goto no_compr;
if (compr->comp_mutex)
mutex_lock(compr->comp_mutex);
err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf,
out_len);
if (compr->comp_mutex)
mutex_unlock(compr->comp_mutex);
if (unlikely(err)) {
ubifs_warn("cannot compress %d bytes, compressor %s, "
"error %d, leave data uncompressed",
in_len, compr->name, err);
goto no_compr;
}
/*
* Presently, we just require that compression results in less data,
* rather than any defined minimum compression ratio or amount.
*/
if (ALIGN(*out_len, 8) >= ALIGN(in_len, 8))
goto no_compr;
return;
no_compr:
memcpy(out_buf, in_buf, in_len);
*out_len = in_len;
*compr_type = UBIFS_COMPR_NONE;
}
/**
* ubifs_decompress - decompress data.
* @in_buf: data to decompress
* @in_len: length of the data to decompress
* @out_buf: output buffer where decompressed data should
* @out_len: output length is returned here
* @compr_type: type of compression
*
* This function decompresses data from buffer @in_buf into buffer @out_buf.
* The length of the uncompressed data is returned in @out_len. This functions
* returns %0 on success or a negative error code on failure.
*/
int ubifs_decompress(const void *in_buf, int in_len, void *out_buf,
int *out_len, int compr_type)
{
int err;
struct ubifs_compressor *compr;
if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
ubifs_err("invalid compression type %d", compr_type);
return -EINVAL;
}
compr = ubifs_compressors[compr_type];
if (unlikely(!compr->capi_name)) {
ubifs_err("%s compression is not compiled in", compr->name);
return -EINVAL;
}
if (compr_type == UBIFS_COMPR_NONE) {
memcpy(out_buf, in_buf, in_len);
*out_len = in_len;
return 0;
}
if (compr->decomp_mutex)
mutex_lock(compr->decomp_mutex);
err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf,
out_len);
if (compr->decomp_mutex)
mutex_unlock(compr->decomp_mutex);
if (err)
ubifs_err("cannot decompress %d bytes, compressor %s, "
"error %d", in_len, compr->name, err);
return err;
}
/**
* compr_init - initialize a compressor.
* @compr: compressor description object
*
* This function initializes the requested compressor and returns zero in case
* of success or a negative error code in case of failure.
*/
static int __init compr_init(struct ubifs_compressor *compr)
{
if (compr->capi_name) {
compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0);
if (IS_ERR(compr->cc)) {
ubifs_err("cannot initialize compressor %s, error %ld",
compr->name, PTR_ERR(compr->cc));
return PTR_ERR(compr->cc);
}
}
ubifs_compressors[compr->compr_type] = compr;
return 0;
}
/**
* compr_exit - de-initialize a compressor.
* @compr: compressor description object
*/
static void compr_exit(struct ubifs_compressor *compr)
{
if (compr->capi_name)
crypto_free_comp(compr->cc);
return;
}
/**
* ubifs_compressors_init - initialize UBIFS compressors.
*
* This function initializes the compressor which were compiled in. Returns
* zero in case of success and a negative error code in case of failure.
*/
int __init ubifs_compressors_init(void)
{
int err;
err = compr_init(&lzo_compr);
if (err)
return err;
err = compr_init(&zlib_compr);
if (err)
goto out_lzo;
ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr;
return 0;
out_lzo:
compr_exit(&lzo_compr);
return err;
}
/**
* ubifs_compressors_exit - de-initialize UBIFS compressors.
*/
void __exit ubifs_compressors_exit(void)
{
compr_exit(&lzo_compr);
compr_exit(&zlib_compr);
}

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/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
#ifndef __UBIFS_DEBUG_H__
#define __UBIFS_DEBUG_H__
#ifdef CONFIG_UBIFS_FS_DEBUG
#define UBIFS_DBG(op) op
#define ubifs_assert(expr) do { \
if (unlikely(!(expr))) { \
printk(KERN_CRIT "UBIFS assert failed in %s at %u (pid %d)\n", \
__func__, __LINE__, current->pid); \
dbg_dump_stack(); \
} \
} while (0)
#define ubifs_assert_cmt_locked(c) do { \
if (unlikely(down_write_trylock(&(c)->commit_sem))) { \
up_write(&(c)->commit_sem); \
printk(KERN_CRIT "commit lock is not locked!\n"); \
ubifs_assert(0); \
} \
} while (0)
#define dbg_dump_stack() do { \
if (!dbg_failure_mode) \
dump_stack(); \
} while (0)
/* Generic debugging messages */
#define dbg_msg(fmt, ...) do { \
spin_lock(&dbg_lock); \
printk(KERN_DEBUG "UBIFS DBG (pid %d): %s: " fmt "\n", current->pid, \
__func__, ##__VA_ARGS__); \
spin_unlock(&dbg_lock); \
} while (0)
#define dbg_do_msg(typ, fmt, ...) do { \
if (ubifs_msg_flags & typ) \
dbg_msg(fmt, ##__VA_ARGS__); \
} while (0)
#define dbg_err(fmt, ...) do { \
spin_lock(&dbg_lock); \
ubifs_err(fmt, ##__VA_ARGS__); \
spin_unlock(&dbg_lock); \
} while (0)
const char *dbg_key_str0(const struct ubifs_info *c,
const union ubifs_key *key);
const char *dbg_key_str1(const struct ubifs_info *c,
const union ubifs_key *key);
/*
* DBGKEY macros require dbg_lock to be held, which it is in the dbg message
* macros.
*/
#define DBGKEY(key) dbg_key_str0(c, (key))
#define DBGKEY1(key) dbg_key_str1(c, (key))
/* General messages */
#define dbg_gen(fmt, ...) dbg_do_msg(UBIFS_MSG_GEN, fmt, ##__VA_ARGS__)
/* Additional journal messages */
#define dbg_jnl(fmt, ...) dbg_do_msg(UBIFS_MSG_JNL, fmt, ##__VA_ARGS__)
/* Additional TNC messages */
#define dbg_tnc(fmt, ...) dbg_do_msg(UBIFS_MSG_TNC, fmt, ##__VA_ARGS__)
/* Additional lprops messages */
#define dbg_lp(fmt, ...) dbg_do_msg(UBIFS_MSG_LP, fmt, ##__VA_ARGS__)
/* Additional LEB find messages */
#define dbg_find(fmt, ...) dbg_do_msg(UBIFS_MSG_FIND, fmt, ##__VA_ARGS__)
/* Additional mount messages */
#define dbg_mnt(fmt, ...) dbg_do_msg(UBIFS_MSG_MNT, fmt, ##__VA_ARGS__)
/* Additional I/O messages */
#define dbg_io(fmt, ...) dbg_do_msg(UBIFS_MSG_IO, fmt, ##__VA_ARGS__)
/* Additional commit messages */
#define dbg_cmt(fmt, ...) dbg_do_msg(UBIFS_MSG_CMT, fmt, ##__VA_ARGS__)
/* Additional budgeting messages */
#define dbg_budg(fmt, ...) dbg_do_msg(UBIFS_MSG_BUDG, fmt, ##__VA_ARGS__)
/* Additional log messages */
#define dbg_log(fmt, ...) dbg_do_msg(UBIFS_MSG_LOG, fmt, ##__VA_ARGS__)
/* Additional gc messages */
#define dbg_gc(fmt, ...) dbg_do_msg(UBIFS_MSG_GC, fmt, ##__VA_ARGS__)
/* Additional scan messages */
#define dbg_scan(fmt, ...) dbg_do_msg(UBIFS_MSG_SCAN, fmt, ##__VA_ARGS__)
/* Additional recovery messages */
#define dbg_rcvry(fmt, ...) dbg_do_msg(UBIFS_MSG_RCVRY, fmt, ##__VA_ARGS__)
/*
* Debugging message type flags (must match msg_type_names in debug.c).
*
* UBIFS_MSG_GEN: general messages
* UBIFS_MSG_JNL: journal messages
* UBIFS_MSG_MNT: mount messages
* UBIFS_MSG_CMT: commit messages
* UBIFS_MSG_FIND: LEB find messages
* UBIFS_MSG_BUDG: budgeting messages
* UBIFS_MSG_GC: garbage collection messages
* UBIFS_MSG_TNC: TNC messages
* UBIFS_MSG_LP: lprops messages
* UBIFS_MSG_IO: I/O messages
* UBIFS_MSG_LOG: log messages
* UBIFS_MSG_SCAN: scan messages
* UBIFS_MSG_RCVRY: recovery messages
*/
enum {
UBIFS_MSG_GEN = 0x1,
UBIFS_MSG_JNL = 0x2,
UBIFS_MSG_MNT = 0x4,
UBIFS_MSG_CMT = 0x8,
UBIFS_MSG_FIND = 0x10,
UBIFS_MSG_BUDG = 0x20,
UBIFS_MSG_GC = 0x40,
UBIFS_MSG_TNC = 0x80,
UBIFS_MSG_LP = 0x100,
UBIFS_MSG_IO = 0x200,
UBIFS_MSG_LOG = 0x400,
UBIFS_MSG_SCAN = 0x800,
UBIFS_MSG_RCVRY = 0x1000,
};
/* Debugging message type flags for each default debug message level */
#define UBIFS_MSG_LVL_0 0
#define UBIFS_MSG_LVL_1 0x1
#define UBIFS_MSG_LVL_2 0x7f
#define UBIFS_MSG_LVL_3 0xffff
/*
* Debugging check flags (must match chk_names in debug.c).
*
* UBIFS_CHK_GEN: general checks
* UBIFS_CHK_TNC: check TNC
* UBIFS_CHK_IDX_SZ: check index size
* UBIFS_CHK_ORPH: check orphans
* UBIFS_CHK_OLD_IDX: check the old index
* UBIFS_CHK_LPROPS: check lprops
* UBIFS_CHK_FS: check the file-system
*/
enum {
UBIFS_CHK_GEN = 0x1,
UBIFS_CHK_TNC = 0x2,
UBIFS_CHK_IDX_SZ = 0x4,
UBIFS_CHK_ORPH = 0x8,
UBIFS_CHK_OLD_IDX = 0x10,
UBIFS_CHK_LPROPS = 0x20,
UBIFS_CHK_FS = 0x40,
};
/*
* Special testing flags (must match tst_names in debug.c).
*
* UBIFS_TST_FORCE_IN_THE_GAPS: force the use of in-the-gaps method
* UBIFS_TST_RCVRY: failure mode for recovery testing
*/
enum {
UBIFS_TST_FORCE_IN_THE_GAPS = 0x2,
UBIFS_TST_RCVRY = 0x4,
};
#if CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 1
#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_1
#elif CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 2
#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_2
#elif CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 3
#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_3
#else
#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_0
#endif
#ifdef CONFIG_UBIFS_FS_DEBUG_CHKS
#define UBIFS_CHK_FLAGS_DEFAULT 0xffffffff
#else
#define UBIFS_CHK_FLAGS_DEFAULT 0
#endif
extern spinlock_t dbg_lock;
extern unsigned int ubifs_msg_flags;
extern unsigned int ubifs_chk_flags;
extern unsigned int ubifs_tst_flags;
/* Dump functions */
const char *dbg_ntype(int type);
const char *dbg_cstate(int cmt_state);
const char *dbg_get_key_dump(const struct ubifs_info *c,
const union ubifs_key *key);
void dbg_dump_inode(const struct ubifs_info *c, const struct inode *inode);
void dbg_dump_node(const struct ubifs_info *c, const void *node);
void dbg_dump_budget_req(const struct ubifs_budget_req *req);
void dbg_dump_lstats(const struct ubifs_lp_stats *lst);
void dbg_dump_budg(struct ubifs_info *c);
void dbg_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp);
void dbg_dump_lprops(struct ubifs_info *c);
void dbg_dump_leb(const struct ubifs_info *c, int lnum);
void dbg_dump_znode(const struct ubifs_info *c,
const struct ubifs_znode *znode);
void dbg_dump_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat);
void dbg_dump_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
struct ubifs_nnode *parent, int iip);
void dbg_dump_tnc(struct ubifs_info *c);
void dbg_dump_index(struct ubifs_info *c);
/* Checking helper functions */
typedef int (*dbg_leaf_callback)(struct ubifs_info *c,
struct ubifs_zbranch *zbr, void *priv);
typedef int (*dbg_znode_callback)(struct ubifs_info *c,
struct ubifs_znode *znode, void *priv);
int dbg_walk_index(struct ubifs_info *c, dbg_leaf_callback leaf_cb,
dbg_znode_callback znode_cb, void *priv);
/* Checking functions */
int dbg_check_lprops(struct ubifs_info *c);
int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot);
int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot);
int dbg_check_cats(struct ubifs_info *c);
int dbg_check_ltab(struct ubifs_info *c);
int dbg_check_synced_i_size(struct inode *inode);
int dbg_check_dir_size(struct ubifs_info *c, const struct inode *dir);
int dbg_check_tnc(struct ubifs_info *c, int extra);
int dbg_check_idx_size(struct ubifs_info *c, long long idx_size);
int dbg_check_filesystem(struct ubifs_info *c);
void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
int add_pos);
int dbg_check_lprops(struct ubifs_info *c);
int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
int row, int col);
/* Force the use of in-the-gaps method for testing */
#define dbg_force_in_the_gaps_enabled \
(ubifs_tst_flags & UBIFS_TST_FORCE_IN_THE_GAPS)
int dbg_force_in_the_gaps(void);
/* Failure mode for recovery testing */
#define dbg_failure_mode (ubifs_tst_flags & UBIFS_TST_RCVRY)
void dbg_failure_mode_registration(struct ubifs_info *c);
void dbg_failure_mode_deregistration(struct ubifs_info *c);
#ifndef UBIFS_DBG_PRESERVE_UBI
#define ubi_leb_read dbg_leb_read
#define ubi_leb_write dbg_leb_write
#define ubi_leb_change dbg_leb_change
#define ubi_leb_erase dbg_leb_erase
#define ubi_leb_unmap dbg_leb_unmap
#define ubi_is_mapped dbg_is_mapped
#define ubi_leb_map dbg_leb_map
#endif
int dbg_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
int len, int check);
int dbg_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
int offset, int len, int dtype);
int dbg_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
int len, int dtype);
int dbg_leb_erase(struct ubi_volume_desc *desc, int lnum);
int dbg_leb_unmap(struct ubi_volume_desc *desc, int lnum);
int dbg_is_mapped(struct ubi_volume_desc *desc, int lnum);
int dbg_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
static inline int dbg_read(struct ubi_volume_desc *desc, int lnum, char *buf,
int offset, int len)
{
return dbg_leb_read(desc, lnum, buf, offset, len, 0);
}
static inline int dbg_write(struct ubi_volume_desc *desc, int lnum,
const void *buf, int offset, int len)
{
return dbg_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
}
static inline int dbg_change(struct ubi_volume_desc *desc, int lnum,
const void *buf, int len)
{
return dbg_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
}
#else /* !CONFIG_UBIFS_FS_DEBUG */
#define UBIFS_DBG(op)
#define ubifs_assert(expr) ({})
#define ubifs_assert_cmt_locked(c)
#define dbg_dump_stack()
#define dbg_err(fmt, ...) ({})
#define dbg_msg(fmt, ...) ({})
#define dbg_key(c, key, fmt, ...) ({})
#define dbg_gen(fmt, ...) ({})
#define dbg_jnl(fmt, ...) ({})
#define dbg_tnc(fmt, ...) ({})
#define dbg_lp(fmt, ...) ({})
#define dbg_find(fmt, ...) ({})
#define dbg_mnt(fmt, ...) ({})
#define dbg_io(fmt, ...) ({})
#define dbg_cmt(fmt, ...) ({})
#define dbg_budg(fmt, ...) ({})
#define dbg_log(fmt, ...) ({})
#define dbg_gc(fmt, ...) ({})
#define dbg_scan(fmt, ...) ({})
#define dbg_rcvry(fmt, ...) ({})
#define dbg_ntype(type) ""
#define dbg_cstate(cmt_state) ""
#define dbg_get_key_dump(c, key) ({})
#define dbg_dump_inode(c, inode) ({})
#define dbg_dump_node(c, node) ({})
#define dbg_dump_budget_req(req) ({})
#define dbg_dump_lstats(lst) ({})
#define dbg_dump_budg(c) ({})
#define dbg_dump_lprop(c, lp) ({})
#define dbg_dump_lprops(c) ({})
#define dbg_dump_leb(c, lnum) ({})
#define dbg_dump_znode(c, znode) ({})
#define dbg_dump_heap(c, heap, cat) ({})
#define dbg_dump_pnode(c, pnode, parent, iip) ({})
#define dbg_dump_tnc(c) ({})
#define dbg_dump_index(c) ({})
#define dbg_walk_index(c, leaf_cb, znode_cb, priv) 0
#define dbg_old_index_check_init(c, zroot) 0
#define dbg_check_old_index(c, zroot) 0
#define dbg_check_cats(c) 0
#define dbg_check_ltab(c) 0
#define dbg_check_synced_i_size(inode) 0
#define dbg_check_dir_size(c, dir) 0
#define dbg_check_tnc(c, x) 0
#define dbg_check_idx_size(c, idx_size) 0
#define dbg_check_filesystem(c) 0
#define dbg_check_heap(c, heap, cat, add_pos) ({})
#define dbg_check_lprops(c) 0
#define dbg_check_lpt_nodes(c, cnode, row, col) 0
#define dbg_force_in_the_gaps_enabled 0
#define dbg_force_in_the_gaps() 0
#define dbg_failure_mode 0
#define dbg_failure_mode_registration(c) ({})
#define dbg_failure_mode_deregistration(c) ({})
#endif /* !CONFIG_UBIFS_FS_DEBUG */
#endif /* !__UBIFS_DEBUG_H__ */

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/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/*
* This file contains functions for finding LEBs for various purposes e.g.
* garbage collection. In general, lprops category heaps and lists are used
* for fast access, falling back on scanning the LPT as a last resort.
*/
#include <linux/sort.h>
#include "ubifs.h"
/**
* struct scan_data - data provided to scan callback functions
* @min_space: minimum number of bytes for which to scan
* @pick_free: whether it is OK to scan for empty LEBs
* @lnum: LEB number found is returned here
* @exclude_index: whether to exclude index LEBs
*/
struct scan_data {
int min_space;
int pick_free;
int lnum;
int exclude_index;
};
/**
* valuable - determine whether LEB properties are valuable.
* @c: the UBIFS file-system description object
* @lprops: LEB properties
*
* This function return %1 if the LEB properties should be added to the LEB
* properties tree in memory. Otherwise %0 is returned.
*/
static int valuable(struct ubifs_info *c, const struct ubifs_lprops *lprops)
{
int n, cat = lprops->flags & LPROPS_CAT_MASK;
struct ubifs_lpt_heap *heap;
switch (cat) {
case LPROPS_DIRTY:
case LPROPS_DIRTY_IDX:
case LPROPS_FREE:
heap = &c->lpt_heap[cat - 1];
if (heap->cnt < heap->max_cnt)
return 1;
if (lprops->free + lprops->dirty >= c->dark_wm)
return 1;
return 0;
case LPROPS_EMPTY:
n = c->lst.empty_lebs + c->freeable_cnt -
c->lst.taken_empty_lebs;
if (n < c->lsave_cnt)
return 1;
return 0;
case LPROPS_FREEABLE:
return 1;
case LPROPS_FRDI_IDX:
return 1;
}
return 0;
}
/**
* scan_for_dirty_cb - dirty space scan callback.
* @c: the UBIFS file-system description object
* @lprops: LEB properties to scan
* @in_tree: whether the LEB properties are in main memory
* @data: information passed to and from the caller of the scan
*
* This function returns a code that indicates whether the scan should continue
* (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
* in main memory (%LPT_SCAN_ADD), or whether the scan should stop
* (%LPT_SCAN_STOP).
*/
static int scan_for_dirty_cb(struct ubifs_info *c,
const struct ubifs_lprops *lprops, int in_tree,
struct scan_data *data)
{
int ret = LPT_SCAN_CONTINUE;
/* Exclude LEBs that are currently in use */
if (lprops->flags & LPROPS_TAKEN)
return LPT_SCAN_CONTINUE;
/* Determine whether to add these LEB properties to the tree */
if (!in_tree && valuable(c, lprops))
ret |= LPT_SCAN_ADD;
/* Exclude LEBs with too little space */
if (lprops->free + lprops->dirty < data->min_space)
return ret;
/* If specified, exclude index LEBs */
if (data->exclude_index && lprops->flags & LPROPS_INDEX)
return ret;
/* If specified, exclude empty or freeable LEBs */
if (lprops->free + lprops->dirty == c->leb_size) {
if (!data->pick_free)
return ret;
/* Exclude LEBs with too little dirty space (unless it is empty) */
} else if (lprops->dirty < c->dead_wm)
return ret;
/* Finally we found space */
data->lnum = lprops->lnum;
return LPT_SCAN_ADD | LPT_SCAN_STOP;
}
/**
* scan_for_dirty - find a data LEB with free space.
* @c: the UBIFS file-system description object
* @min_space: minimum amount free plus dirty space the returned LEB has to
* have
* @pick_free: if it is OK to return a free or freeable LEB
* @exclude_index: whether to exclude index LEBs
*
* This function returns a pointer to the LEB properties found or a negative
* error code.
*/
static const struct ubifs_lprops *scan_for_dirty(struct ubifs_info *c,
int min_space, int pick_free,
int exclude_index)
{
const struct ubifs_lprops *lprops;
struct ubifs_lpt_heap *heap;
struct scan_data data;
int err, i;
/* There may be an LEB with enough dirty space on the free heap */
heap = &c->lpt_heap[LPROPS_FREE - 1];
for (i = 0; i < heap->cnt; i++) {
lprops = heap->arr[i];
if (lprops->free + lprops->dirty < min_space)
continue;
if (lprops->dirty < c->dead_wm)
continue;
return lprops;
}
/*
* A LEB may have fallen off of the bottom of the dirty heap, and ended
* up as uncategorized even though it has enough dirty space for us now,
* so check the uncategorized list. N.B. neither empty nor freeable LEBs
* can end up as uncategorized because they are kept on lists not
* finite-sized heaps.
*/
list_for_each_entry(lprops, &c->uncat_list, list) {
if (lprops->flags & LPROPS_TAKEN)
continue;
if (lprops->free + lprops->dirty < min_space)
continue;
if (exclude_index && (lprops->flags & LPROPS_INDEX))
continue;
if (lprops->dirty < c->dead_wm)
continue;
return lprops;
}
/* We have looked everywhere in main memory, now scan the flash */
if (c->pnodes_have >= c->pnode_cnt)
/* All pnodes are in memory, so skip scan */
return ERR_PTR(-ENOSPC);
data.min_space = min_space;
data.pick_free = pick_free;
data.lnum = -1;
data.exclude_index = exclude_index;
err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
(ubifs_lpt_scan_callback)scan_for_dirty_cb,
&data);
if (err)
return ERR_PTR(err);
ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
c->lscan_lnum = data.lnum;
lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
if (IS_ERR(lprops))
return lprops;
ubifs_assert(lprops->lnum == data.lnum);
ubifs_assert(lprops->free + lprops->dirty >= min_space);
ubifs_assert(lprops->dirty >= c->dead_wm ||
(pick_free &&
lprops->free + lprops->dirty == c->leb_size));
ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
ubifs_assert(!exclude_index || !(lprops->flags & LPROPS_INDEX));
return lprops;
}
/**
* ubifs_find_dirty_leb - find a dirty LEB for the Garbage Collector.
* @c: the UBIFS file-system description object
* @ret_lp: LEB properties are returned here on exit
* @min_space: minimum amount free plus dirty space the returned LEB has to
* have
* @pick_free: controls whether it is OK to pick empty or index LEBs
*
* This function tries to find a dirty logical eraseblock which has at least
* @min_space free and dirty space. It prefers to take an LEB from the dirty or
* dirty index heap, and it falls-back to LPT scanning if the heaps are empty
* or do not have an LEB which satisfies the @min_space criteria.
*
* Note:
* o LEBs which have less than dead watermark of dirty space are never picked
* by this function;
*
* Returns zero and the LEB properties of
* found dirty LEB in case of success, %-ENOSPC if no dirty LEB was found and a
* negative error code in case of other failures. The returned LEB is marked as
* "taken".
*
* The additional @pick_free argument controls if this function has to return a
* free or freeable LEB if one is present. For example, GC must to set it to %1,
* when called from the journal space reservation function, because the
* appearance of free space may coincide with the loss of enough dirty space
* for GC to succeed anyway.
*
* In contrast, if the Garbage Collector is called from budgeting, it should
* just make free space, not return LEBs which are already free or freeable.
*
* In addition @pick_free is set to %2 by the recovery process in order to
* recover gc_lnum in which case an index LEB must not be returned.
*/
int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
int min_space, int pick_free)
{
int err = 0, sum, exclude_index = pick_free == 2 ? 1 : 0;
const struct ubifs_lprops *lp = NULL, *idx_lp = NULL;
struct ubifs_lpt_heap *heap, *idx_heap;
ubifs_get_lprops(c);
if (pick_free) {
int lebs, rsvd_idx_lebs = 0;
spin_lock(&c->space_lock);
lebs = c->lst.empty_lebs;
lebs += c->freeable_cnt - c->lst.taken_empty_lebs;
/*
* Note, the index may consume more LEBs than have been reserved
* for it. It is OK because it might be consolidated by GC.
* But if the index takes fewer LEBs than it is reserved for it,
* this function must avoid picking those reserved LEBs.
*/
if (c->min_idx_lebs >= c->lst.idx_lebs) {
rsvd_idx_lebs = c->min_idx_lebs - c->lst.idx_lebs;
exclude_index = 1;
}
spin_unlock(&c->space_lock);
/* Check if there are enough free LEBs for the index */
if (rsvd_idx_lebs < lebs) {
/* OK, try to find an empty LEB */
lp = ubifs_fast_find_empty(c);
if (lp)
goto found;
/* Or a freeable LEB */
lp = ubifs_fast_find_freeable(c);
if (lp)
goto found;
} else
/*
* We cannot pick free/freeable LEBs in the below code.
*/
pick_free = 0;
} else {
spin_lock(&c->space_lock);
exclude_index = (c->min_idx_lebs >= c->lst.idx_lebs);
spin_unlock(&c->space_lock);
}
/* Look on the dirty and dirty index heaps */
heap = &c->lpt_heap[LPROPS_DIRTY - 1];
idx_heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
if (idx_heap->cnt && !exclude_index) {
idx_lp = idx_heap->arr[0];
sum = idx_lp->free + idx_lp->dirty;
/*
* Since we reserve twice as more space for the index than it
* actually takes, it does not make sense to pick indexing LEBs
* with less than half LEB of dirty space.
*/
if (sum < min_space || sum < c->half_leb_size)
idx_lp = NULL;
}
if (heap->cnt) {
lp = heap->arr[0];
if (lp->dirty + lp->free < min_space)
lp = NULL;
}
/* Pick the LEB with most space */
if (idx_lp && lp) {
if (idx_lp->free + idx_lp->dirty >= lp->free + lp->dirty)
lp = idx_lp;
} else if (idx_lp && !lp)
lp = idx_lp;
if (lp) {
ubifs_assert(lp->dirty >= c->dead_wm);
goto found;
}
/* Did not find a dirty LEB on the dirty heaps, have to scan */
dbg_find("scanning LPT for a dirty LEB");
lp = scan_for_dirty(c, min_space, pick_free, exclude_index);
if (IS_ERR(lp)) {
err = PTR_ERR(lp);
goto out;
}
ubifs_assert(lp->dirty >= c->dead_wm ||
(pick_free && lp->free + lp->dirty == c->leb_size));
found:
dbg_find("found LEB %d, free %d, dirty %d, flags %#x",
lp->lnum, lp->free, lp->dirty, lp->flags);
lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
lp->flags | LPROPS_TAKEN, 0);
if (IS_ERR(lp)) {
err = PTR_ERR(lp);
goto out;
}
memcpy(ret_lp, lp, sizeof(struct ubifs_lprops));
out:
ubifs_release_lprops(c);
return err;
}
/**
* scan_for_free_cb - free space scan callback.
* @c: the UBIFS file-system description object
* @lprops: LEB properties to scan
* @in_tree: whether the LEB properties are in main memory
* @data: information passed to and from the caller of the scan
*
* This function returns a code that indicates whether the scan should continue
* (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
* in main memory (%LPT_SCAN_ADD), or whether the scan should stop
* (%LPT_SCAN_STOP).
*/
static int scan_for_free_cb(struct ubifs_info *c,
const struct ubifs_lprops *lprops, int in_tree,
struct scan_data *data)
{
int ret = LPT_SCAN_CONTINUE;
/* Exclude LEBs that are currently in use */
if (lprops->flags & LPROPS_TAKEN)
return LPT_SCAN_CONTINUE;
/* Determine whether to add these LEB properties to the tree */
if (!in_tree && valuable(c, lprops))
ret |= LPT_SCAN_ADD;
/* Exclude index LEBs */
if (lprops->flags & LPROPS_INDEX)
return ret;
/* Exclude LEBs with too little space */
if (lprops->free < data->min_space)
return ret;
/* If specified, exclude empty LEBs */
if (!data->pick_free && lprops->free == c->leb_size)
return ret;
/*
* LEBs that have only free and dirty space must not be allocated
* because they may have been unmapped already or they may have data
* that is obsolete only because of nodes that are still sitting in a
* wbuf.
*/
if (lprops->free + lprops->dirty == c->leb_size && lprops->dirty > 0)
return ret;
/* Finally we found space */
data->lnum = lprops->lnum;
return LPT_SCAN_ADD | LPT_SCAN_STOP;
}
/**
* do_find_free_space - find a data LEB with free space.
* @c: the UBIFS file-system description object
* @min_space: minimum amount of free space required
* @pick_free: whether it is OK to scan for empty LEBs
* @squeeze: whether to try to find space in a non-empty LEB first
*
* This function returns a pointer to the LEB properties found or a negative
* error code.
*/
static
const struct ubifs_lprops *do_find_free_space(struct ubifs_info *c,
int min_space, int pick_free,
int squeeze)
{
const struct ubifs_lprops *lprops;
struct ubifs_lpt_heap *heap;
struct scan_data data;
int err, i;
if (squeeze) {
lprops = ubifs_fast_find_free(c);
if (lprops && lprops->free >= min_space)
return lprops;
}
if (pick_free) {
lprops = ubifs_fast_find_empty(c);
if (lprops)
return lprops;
}
if (!squeeze) {
lprops = ubifs_fast_find_free(c);
if (lprops && lprops->free >= min_space)
return lprops;
}
/* There may be an LEB with enough free space on the dirty heap */
heap = &c->lpt_heap[LPROPS_DIRTY - 1];
for (i = 0; i < heap->cnt; i++) {
lprops = heap->arr[i];
if (lprops->free >= min_space)
return lprops;
}
/*
* A LEB may have fallen off of the bottom of the free heap, and ended
* up as uncategorized even though it has enough free space for us now,
* so check the uncategorized list. N.B. neither empty nor freeable LEBs
* can end up as uncategorized because they are kept on lists not
* finite-sized heaps.
*/
list_for_each_entry(lprops, &c->uncat_list, list) {
if (lprops->flags & LPROPS_TAKEN)
continue;
if (lprops->flags & LPROPS_INDEX)
continue;
if (lprops->free >= min_space)
return lprops;
}
/* We have looked everywhere in main memory, now scan the flash */
if (c->pnodes_have >= c->pnode_cnt)
/* All pnodes are in memory, so skip scan */
return ERR_PTR(-ENOSPC);
data.min_space = min_space;
data.pick_free = pick_free;
data.lnum = -1;
err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
(ubifs_lpt_scan_callback)scan_for_free_cb,
&data);
if (err)
return ERR_PTR(err);
ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
c->lscan_lnum = data.lnum;
lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
if (IS_ERR(lprops))
return lprops;
ubifs_assert(lprops->lnum == data.lnum);
ubifs_assert(lprops->free >= min_space);
ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
ubifs_assert(!(lprops->flags & LPROPS_INDEX));
return lprops;
}
/**
* ubifs_find_free_space - find a data LEB with free space.
* @c: the UBIFS file-system description object
* @min_space: minimum amount of required free space
* @free: contains amount of free space in the LEB on exit
* @squeeze: whether to try to find space in a non-empty LEB first
*
* This function looks for an LEB with at least @min_space bytes of free space.
* It tries to find an empty LEB if possible. If no empty LEBs are available,
* this function searches for a non-empty data LEB. The returned LEB is marked
* as "taken".
*
* This function returns found LEB number in case of success, %-ENOSPC if it
* failed to find a LEB with @min_space bytes of free space and other a negative
* error codes in case of failure.
*/
int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *free,
int squeeze)
{
const struct ubifs_lprops *lprops;
int lebs, rsvd_idx_lebs, pick_free = 0, err, lnum, flags;
dbg_find("min_space %d", min_space);
ubifs_get_lprops(c);
/* Check if there are enough empty LEBs for commit */
spin_lock(&c->space_lock);
if (c->min_idx_lebs > c->lst.idx_lebs)
rsvd_idx_lebs = c->min_idx_lebs - c->lst.idx_lebs;
else
rsvd_idx_lebs = 0;
lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
c->lst.taken_empty_lebs;
ubifs_assert(lebs + c->lst.idx_lebs >= c->min_idx_lebs);
if (rsvd_idx_lebs < lebs)
/*
* OK to allocate an empty LEB, but we still don't want to go
* looking for one if there aren't any.
*/
if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
pick_free = 1;
/*
* Because we release the space lock, we must account
* for this allocation here. After the LEB properties
* flags have been updated, we subtract one. Note, the
* result of this is that lprops also decreases
* @taken_empty_lebs in 'ubifs_change_lp()', so it is
* off by one for a short period of time which may
* introduce a small disturbance to budgeting
* calculations, but this is harmless because at the
* worst case this would make the budgeting subsystem
* be more pessimistic than needed.
*
* Fundamentally, this is about serialization of the
* budgeting and lprops subsystems. We could make the
* @space_lock a mutex and avoid dropping it before
* calling 'ubifs_change_lp()', but mutex is more
* heavy-weight, and we want budgeting to be as fast as
* possible.
*/
c->lst.taken_empty_lebs += 1;
}
spin_unlock(&c->space_lock);
lprops = do_find_free_space(c, min_space, pick_free, squeeze);
if (IS_ERR(lprops)) {
err = PTR_ERR(lprops);
goto out;
}
lnum = lprops->lnum;
flags = lprops->flags | LPROPS_TAKEN;
lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC, flags, 0);
if (IS_ERR(lprops)) {
err = PTR_ERR(lprops);
goto out;
}
if (pick_free) {
spin_lock(&c->space_lock);
c->lst.taken_empty_lebs -= 1;
spin_unlock(&c->space_lock);
}
*free = lprops->free;
ubifs_release_lprops(c);
if (*free == c->leb_size) {
/*
* Ensure that empty LEBs have been unmapped. They may not have
* been, for example, because of an unclean unmount. Also
* LEBs that were freeable LEBs (free + dirty == leb_size) will
* not have been unmapped.
*/
err = ubifs_leb_unmap(c, lnum);
if (err)
return err;
}
dbg_find("found LEB %d, free %d", lnum, *free);
ubifs_assert(*free >= min_space);
return lnum;
out:
if (pick_free) {
spin_lock(&c->space_lock);
c->lst.taken_empty_lebs -= 1;
spin_unlock(&c->space_lock);
}
ubifs_release_lprops(c);
return err;
}
/**
* scan_for_idx_cb - callback used by the scan for a free LEB for the index.
* @c: the UBIFS file-system description object
* @lprops: LEB properties to scan
* @in_tree: whether the LEB properties are in main memory
* @data: information passed to and from the caller of the scan
*
* This function returns a code that indicates whether the scan should continue
* (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
* in main memory (%LPT_SCAN_ADD), or whether the scan should stop
* (%LPT_SCAN_STOP).
*/
static int scan_for_idx_cb(struct ubifs_info *c,
const struct ubifs_lprops *lprops, int in_tree,
struct scan_data *data)
{
int ret = LPT_SCAN_CONTINUE;
/* Exclude LEBs that are currently in use */
if (lprops->flags & LPROPS_TAKEN)
return LPT_SCAN_CONTINUE;
/* Determine whether to add these LEB properties to the tree */
if (!in_tree && valuable(c, lprops))
ret |= LPT_SCAN_ADD;
/* Exclude index LEBS */
if (lprops->flags & LPROPS_INDEX)
return ret;
/* Exclude LEBs that cannot be made empty */
if (lprops->free + lprops->dirty != c->leb_size)
return ret;
/*
* We are allocating for the index so it is safe to allocate LEBs with
* only free and dirty space, because write buffers are sync'd at commit
* start.
*/
data->lnum = lprops->lnum;
return LPT_SCAN_ADD | LPT_SCAN_STOP;
}
/**
* scan_for_leb_for_idx - scan for a free LEB for the index.
* @c: the UBIFS file-system description object
*/
static const struct ubifs_lprops *scan_for_leb_for_idx(struct ubifs_info *c)
{
struct ubifs_lprops *lprops;
struct scan_data data;
int err;
data.lnum = -1;
err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
(ubifs_lpt_scan_callback)scan_for_idx_cb,
&data);
if (err)
return ERR_PTR(err);
ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
c->lscan_lnum = data.lnum;
lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
if (IS_ERR(lprops))
return lprops;
ubifs_assert(lprops->lnum == data.lnum);
ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
ubifs_assert(!(lprops->flags & LPROPS_INDEX));
return lprops;
}
/**
* ubifs_find_free_leb_for_idx - find a free LEB for the index.
* @c: the UBIFS file-system description object
*
* This function looks for a free LEB and returns that LEB number. The returned
* LEB is marked as "taken", "index".
*
* Only empty LEBs are allocated. This is for two reasons. First, the commit
* calculates the number of LEBs to allocate based on the assumption that they
* will be empty. Secondly, free space at the end of an index LEB is not
* guaranteed to be empty because it may have been used by the in-the-gaps
* method prior to an unclean unmount.
*
* If no LEB is found %-ENOSPC is returned. For other failures another negative
* error code is returned.
*/
int ubifs_find_free_leb_for_idx(struct ubifs_info *c)
{
const struct ubifs_lprops *lprops;
int lnum = -1, err, flags;
ubifs_get_lprops(c);
lprops = ubifs_fast_find_empty(c);
if (!lprops) {
lprops = ubifs_fast_find_freeable(c);
if (!lprops) {
ubifs_assert(c->freeable_cnt == 0);
if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
lprops = scan_for_leb_for_idx(c);
if (IS_ERR(lprops)) {
err = PTR_ERR(lprops);
goto out;
}
}
}
}
if (!lprops) {
err = -ENOSPC;
goto out;
}
lnum = lprops->lnum;
dbg_find("found LEB %d, free %d, dirty %d, flags %#x",
lnum, lprops->free, lprops->dirty, lprops->flags);
flags = lprops->flags | LPROPS_TAKEN | LPROPS_INDEX;
lprops = ubifs_change_lp(c, lprops, c->leb_size, 0, flags, 0);
if (IS_ERR(lprops)) {
err = PTR_ERR(lprops);
goto out;
}
ubifs_release_lprops(c);
/*
* Ensure that empty LEBs have been unmapped. They may not have been,
* for example, because of an unclean unmount. Also LEBs that were
* freeable LEBs (free + dirty == leb_size) will not have been unmapped.
*/
err = ubifs_leb_unmap(c, lnum);
if (err) {
ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
LPROPS_TAKEN | LPROPS_INDEX, 0);
return err;
}
return lnum;
out:
ubifs_release_lprops(c);
return err;
}
static int cmp_dirty_idx(const struct ubifs_lprops **a,
const struct ubifs_lprops **b)
{
const struct ubifs_lprops *lpa = *a;
const struct ubifs_lprops *lpb = *b;
return lpa->dirty + lpa->free - lpb->dirty - lpb->free;
}
static void swap_dirty_idx(struct ubifs_lprops **a, struct ubifs_lprops **b,
int size)
{
struct ubifs_lprops *t = *a;
*a = *b;
*b = t;
}
/**
* ubifs_save_dirty_idx_lnums - save an array of the most dirty index LEB nos.
* @c: the UBIFS file-system description object
*
* This function is called each commit to create an array of LEB numbers of
* dirty index LEBs sorted in order of dirty and free space. This is used by
* the in-the-gaps method of TNC commit.
*/
int ubifs_save_dirty_idx_lnums(struct ubifs_info *c)
{
int i;
ubifs_get_lprops(c);
/* Copy the LPROPS_DIRTY_IDX heap */
c->dirty_idx.cnt = c->lpt_heap[LPROPS_DIRTY_IDX - 1].cnt;
memcpy(c->dirty_idx.arr, c->lpt_heap[LPROPS_DIRTY_IDX - 1].arr,
sizeof(void *) * c->dirty_idx.cnt);
/* Sort it so that the dirtiest is now at the end */
sort(c->dirty_idx.arr, c->dirty_idx.cnt, sizeof(void *),
(int (*)(const void *, const void *))cmp_dirty_idx,
(void (*)(void *, void *, int))swap_dirty_idx);
dbg_find("found %d dirty index LEBs", c->dirty_idx.cnt);
if (c->dirty_idx.cnt)
dbg_find("dirtiest index LEB is %d with dirty %d and free %d",
c->dirty_idx.arr[c->dirty_idx.cnt - 1]->lnum,
c->dirty_idx.arr[c->dirty_idx.cnt - 1]->dirty,
c->dirty_idx.arr[c->dirty_idx.cnt - 1]->free);
/* Replace the lprops pointers with LEB numbers */
for (i = 0; i < c->dirty_idx.cnt; i++)
c->dirty_idx.arr[i] = (void *)(size_t)c->dirty_idx.arr[i]->lnum;
ubifs_release_lprops(c);
return 0;
}
/**
* scan_dirty_idx_cb - callback used by the scan for a dirty index LEB.
* @c: the UBIFS file-system description object
* @lprops: LEB properties to scan
* @in_tree: whether the LEB properties are in main memory
* @data: information passed to and from the caller of the scan
*
* This function returns a code that indicates whether the scan should continue
* (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
* in main memory (%LPT_SCAN_ADD), or whether the scan should stop
* (%LPT_SCAN_STOP).
*/
static int scan_dirty_idx_cb(struct ubifs_info *c,
const struct ubifs_lprops *lprops, int in_tree,
struct scan_data *data)
{
int ret = LPT_SCAN_CONTINUE;
/* Exclude LEBs that are currently in use */
if (lprops->flags & LPROPS_TAKEN)
return LPT_SCAN_CONTINUE;
/* Determine whether to add these LEB properties to the tree */
if (!in_tree && valuable(c, lprops))
ret |= LPT_SCAN_ADD;
/* Exclude non-index LEBs */
if (!(lprops->flags & LPROPS_INDEX))
return ret;
/* Exclude LEBs with too little space */
if (lprops->free + lprops->dirty < c->min_idx_node_sz)
return ret;
/* Finally we found space */
data->lnum = lprops->lnum;
return LPT_SCAN_ADD | LPT_SCAN_STOP;
}
/**
* find_dirty_idx_leb - find a dirty index LEB.
* @c: the UBIFS file-system description object
*
* This function returns LEB number upon success and a negative error code upon
* failure. In particular, -ENOSPC is returned if a dirty index LEB is not
* found.
*
* Note that this function scans the entire LPT but it is called very rarely.
*/
static int find_dirty_idx_leb(struct ubifs_info *c)
{
const struct ubifs_lprops *lprops;
struct ubifs_lpt_heap *heap;
struct scan_data data;
int err, i, ret;
/* Check all structures in memory first */
data.lnum = -1;
heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
for (i = 0; i < heap->cnt; i++) {
lprops = heap->arr[i];
ret = scan_dirty_idx_cb(c, lprops, 1, &data);
if (ret & LPT_SCAN_STOP)
goto found;
}
list_for_each_entry(lprops, &c->frdi_idx_list, list) {
ret = scan_dirty_idx_cb(c, lprops, 1, &data);
if (ret & LPT_SCAN_STOP)
goto found;
}
list_for_each_entry(lprops, &c->uncat_list, list) {
ret = scan_dirty_idx_cb(c, lprops, 1, &data);
if (ret & LPT_SCAN_STOP)
goto found;
}
if (c->pnodes_have >= c->pnode_cnt)
/* All pnodes are in memory, so skip scan */
return -ENOSPC;
err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
(ubifs_lpt_scan_callback)scan_dirty_idx_cb,
&data);
if (err)
return err;
found:
ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
c->lscan_lnum = data.lnum;
lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
if (IS_ERR(lprops))
return PTR_ERR(lprops);
ubifs_assert(lprops->lnum == data.lnum);
ubifs_assert(lprops->free + lprops->dirty >= c->min_idx_node_sz);
ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
ubifs_assert((lprops->flags & LPROPS_INDEX));
dbg_find("found dirty LEB %d, free %d, dirty %d, flags %#x",
lprops->lnum, lprops->free, lprops->dirty, lprops->flags);
lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC,
lprops->flags | LPROPS_TAKEN, 0);
if (IS_ERR(lprops))
return PTR_ERR(lprops);
return lprops->lnum;
}
/**
* get_idx_gc_leb - try to get a LEB number from trivial GC.
* @c: the UBIFS file-system description object
*/
static int get_idx_gc_leb(struct ubifs_info *c)
{
const struct ubifs_lprops *lp;
int err, lnum;
err = ubifs_get_idx_gc_leb(c);
if (err < 0)
return err;
lnum = err;
/*
* The LEB was due to be unmapped after the commit but
* it is needed now for this commit.
*/
lp = ubifs_lpt_lookup_dirty(c, lnum);
if (unlikely(IS_ERR(lp)))
return PTR_ERR(lp);
lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
lp->flags | LPROPS_INDEX, -1);
if (unlikely(IS_ERR(lp)))
return PTR_ERR(lp);
dbg_find("LEB %d, dirty %d and free %d flags %#x",
lp->lnum, lp->dirty, lp->free, lp->flags);
return lnum;
}
/**
* find_dirtiest_idx_leb - find dirtiest index LEB from dirtiest array.
* @c: the UBIFS file-system description object
*/
static int find_dirtiest_idx_leb(struct ubifs_info *c)
{
const struct ubifs_lprops *lp;
int lnum;
while (1) {
if (!c->dirty_idx.cnt)
return -ENOSPC;
/* The lprops pointers were replaced by LEB numbers */
lnum = (size_t)c->dirty_idx.arr[--c->dirty_idx.cnt];
lp = ubifs_lpt_lookup(c, lnum);
if (IS_ERR(lp))
return PTR_ERR(lp);
if ((lp->flags & LPROPS_TAKEN) || !(lp->flags & LPROPS_INDEX))
continue;
lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
lp->flags | LPROPS_TAKEN, 0);
if (IS_ERR(lp))
return PTR_ERR(lp);
break;
}
dbg_find("LEB %d, dirty %d and free %d flags %#x", lp->lnum, lp->dirty,
lp->free, lp->flags);
ubifs_assert(lp->flags | LPROPS_TAKEN);
ubifs_assert(lp->flags | LPROPS_INDEX);
return lnum;
}
/**
* ubifs_find_dirty_idx_leb - try to find dirtiest index LEB as at last commit.
* @c: the UBIFS file-system description object
*
* This function attempts to find an untaken index LEB with the most free and
* dirty space that can be used without overwriting index nodes that were in the
* last index committed.
*/
int ubifs_find_dirty_idx_leb(struct ubifs_info *c)
{
int err;
ubifs_get_lprops(c);
/*
* We made an array of the dirtiest index LEB numbers as at the start of
* last commit. Try that array first.
*/
err = find_dirtiest_idx_leb(c);
/* Next try scanning the entire LPT */
if (err == -ENOSPC)
err = find_dirty_idx_leb(c);
/* Finally take any index LEBs awaiting trivial GC */
if (err == -ENOSPC)
err = get_idx_gc_leb(c);
ubifs_release_lprops(c);
return err;
}

773
fs/ubifs/gc.c Normal file
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@ -0,0 +1,773 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Adrian Hunter
* Artem Bityutskiy (Битюцкий Артём)
*/
/*
* This file implements garbage collection. The procedure for garbage collection
* is different depending on whether a LEB as an index LEB (contains index
* nodes) or not. For non-index LEBs, garbage collection finds a LEB which
* contains a lot of dirty space (obsolete nodes), and copies the non-obsolete
* nodes to the journal, at which point the garbage-collected LEB is free to be
* reused. For index LEBs, garbage collection marks the non-obsolete index nodes
* dirty in the TNC, and after the next commit, the garbage-collected LEB is
* to be reused. Garbage collection will cause the number of dirty index nodes
* to grow, however sufficient space is reserved for the index to ensure the
* commit will never run out of space.
*/
#include <linux/pagemap.h>
#include "ubifs.h"
/*
* GC tries to optimize the way it fit nodes to available space, and it sorts
* nodes a little. The below constants are watermarks which define "large",
* "medium", and "small" nodes.
*/
#define MEDIUM_NODE_WM (UBIFS_BLOCK_SIZE / 4)
#define SMALL_NODE_WM UBIFS_MAX_DENT_NODE_SZ
/*
* GC may need to move more then one LEB to make progress. The below constants
* define "soft" and "hard" limits on the number of LEBs the garbage collector
* may move.
*/
#define SOFT_LEBS_LIMIT 4
#define HARD_LEBS_LIMIT 32
/**
* switch_gc_head - switch the garbage collection journal head.
* @c: UBIFS file-system description object
* @buf: buffer to write
* @len: length of the buffer to write
* @lnum: LEB number written is returned here
* @offs: offset written is returned here
*
* This function switch the GC head to the next LEB which is reserved in
* @c->gc_lnum. Returns %0 in case of success, %-EAGAIN if commit is required,
* and other negative error code in case of failures.
*/
static int switch_gc_head(struct ubifs_info *c)
{
int err, gc_lnum = c->gc_lnum;
struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
ubifs_assert(gc_lnum != -1);
dbg_gc("switch GC head from LEB %d:%d to LEB %d (waste %d bytes)",
wbuf->lnum, wbuf->offs + wbuf->used, gc_lnum,
c->leb_size - wbuf->offs - wbuf->used);
err = ubifs_wbuf_sync_nolock(wbuf);
if (err)
return err;
/*
* The GC write-buffer was synchronized, we may safely unmap
* 'c->gc_lnum'.
*/
err = ubifs_leb_unmap(c, gc_lnum);
if (err)
return err;
err = ubifs_add_bud_to_log(c, GCHD, gc_lnum, 0);
if (err)
return err;
c->gc_lnum = -1;
err = ubifs_wbuf_seek_nolock(wbuf, gc_lnum, 0, UBI_LONGTERM);
return err;
}
/**
* move_nodes - move nodes.
* @c: UBIFS file-system description object
* @sleb: describes nodes to move
*
* This function moves valid nodes from data LEB described by @sleb to the GC
* journal head. The obsolete nodes are dropped.
*
* When moving nodes we have to deal with classical bin-packing problem: the
* space in the current GC journal head LEB and in @c->gc_lnum are the "bins",
* where the nodes in the @sleb->nodes list are the elements which should be
* fit optimally to the bins. This function uses the "first fit decreasing"
* strategy, although it does not really sort the nodes but just split them on
* 3 classes - large, medium, and small, so they are roughly sorted.
*
* This function returns zero in case of success, %-EAGAIN if commit is
* required, and other negative error codes in case of other failures.
*/
static int move_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb)
{
struct ubifs_scan_node *snod, *tmp;
struct list_head large, medium, small;
struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
int avail, err, min = INT_MAX;
INIT_LIST_HEAD(&large);
INIT_LIST_HEAD(&medium);
INIT_LIST_HEAD(&small);
list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) {
struct list_head *lst;
ubifs_assert(snod->type != UBIFS_IDX_NODE);
ubifs_assert(snod->type != UBIFS_REF_NODE);
ubifs_assert(snod->type != UBIFS_CS_NODE);
err = ubifs_tnc_has_node(c, &snod->key, 0, sleb->lnum,
snod->offs, 0);
if (err < 0)
goto out;
lst = &snod->list;
list_del(lst);
if (!err) {
/* The node is obsolete, remove it from the list */
kfree(snod);
continue;
}
/*
* Sort the list of nodes so that large nodes go first, and
* small nodes go last.
*/
if (snod->len > MEDIUM_NODE_WM)
list_add(lst, &large);
else if (snod->len > SMALL_NODE_WM)
list_add(lst, &medium);
else
list_add(lst, &small);
/* And find the smallest node */
if (snod->len < min)
min = snod->len;
}
/*
* Join the tree lists so that we'd have one roughly sorted list
* ('large' will be the head of the joined list).
*/
list_splice(&medium, large.prev);
list_splice(&small, large.prev);
if (wbuf->lnum == -1) {
/*
* The GC journal head is not set, because it is the first GC
* invocation since mount.
*/
err = switch_gc_head(c);
if (err)
goto out;
}
/* Write nodes to their new location. Use the first-fit strategy */
while (1) {
avail = c->leb_size - wbuf->offs - wbuf->used;
list_for_each_entry_safe(snod, tmp, &large, list) {
int new_lnum, new_offs;
if (avail < min)
break;
if (snod->len > avail)
/* This node does not fit */
continue;
cond_resched();
new_lnum = wbuf->lnum;
new_offs = wbuf->offs + wbuf->used;
err = ubifs_wbuf_write_nolock(wbuf, snod->node,
snod->len);
if (err)
goto out;
err = ubifs_tnc_replace(c, &snod->key, sleb->lnum,
snod->offs, new_lnum, new_offs,
snod->len);
if (err)
goto out;
avail = c->leb_size - wbuf->offs - wbuf->used;
list_del(&snod->list);
kfree(snod);
}
if (list_empty(&large))
break;
/*
* Waste the rest of the space in the LEB and switch to the
* next LEB.
*/
err = switch_gc_head(c);
if (err)
goto out;
}
return 0;
out:
list_for_each_entry_safe(snod, tmp, &large, list) {
list_del(&snod->list);
kfree(snod);
}
return err;
}
/**
* gc_sync_wbufs - sync write-buffers for GC.
* @c: UBIFS file-system description object
*
* We must guarantee that obsoleting nodes are on flash. Unfortunately they may
* be in a write-buffer instead. That is, a node could be written to a
* write-buffer, obsoleting another node in a LEB that is GC'd. If that LEB is
* erased before the write-buffer is sync'd and then there is an unclean
* unmount, then an existing node is lost. To avoid this, we sync all
* write-buffers.
*
* This function returns %0 on success or a negative error code on failure.
*/
static int gc_sync_wbufs(struct ubifs_info *c)
{
int err, i;
for (i = 0; i < c->jhead_cnt; i++) {
if (i == GCHD)
continue;
err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
if (err)
return err;
}
return 0;
}
/**
* ubifs_garbage_collect_leb - garbage-collect a logical eraseblock.
* @c: UBIFS file-system description object
* @lp: describes the LEB to garbage collect
*
* This function garbage-collects an LEB and returns one of the @LEB_FREED,
* @LEB_RETAINED, etc positive codes in case of success, %-EAGAIN if commit is
* required, and other negative error codes in case of failures.
*/
int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp)
{
struct ubifs_scan_leb *sleb;
struct ubifs_scan_node *snod;
struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
int err = 0, lnum = lp->lnum;
ubifs_assert(c->gc_lnum != -1 || wbuf->offs + wbuf->used == 0 ||
c->need_recovery);
ubifs_assert(c->gc_lnum != lnum);
ubifs_assert(wbuf->lnum != lnum);
/*
* We scan the entire LEB even though we only really need to scan up to
* (c->leb_size - lp->free).
*/
sleb = ubifs_scan(c, lnum, 0, c->sbuf);
if (IS_ERR(sleb))
return PTR_ERR(sleb);
ubifs_assert(!list_empty(&sleb->nodes));
snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
if (snod->type == UBIFS_IDX_NODE) {
struct ubifs_gced_idx_leb *idx_gc;
dbg_gc("indexing LEB %d (free %d, dirty %d)",
lnum, lp->free, lp->dirty);
list_for_each_entry(snod, &sleb->nodes, list) {
struct ubifs_idx_node *idx = snod->node;
int level = le16_to_cpu(idx->level);
ubifs_assert(snod->type == UBIFS_IDX_NODE);
key_read(c, ubifs_idx_key(c, idx), &snod->key);
err = ubifs_dirty_idx_node(c, &snod->key, level, lnum,
snod->offs);
if (err)
goto out;
}
idx_gc = kmalloc(sizeof(struct ubifs_gced_idx_leb), GFP_NOFS);
if (!idx_gc) {
err = -ENOMEM;
goto out;
}
idx_gc->lnum = lnum;
idx_gc->unmap = 0;
list_add(&idx_gc->list, &c->idx_gc);
/*
* Don't release the LEB until after the next commit, because
* it may contain date which is needed for recovery. So
* although we freed this LEB, it will become usable only after
* the commit.
*/
err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0,
LPROPS_INDEX, 1);
if (err)
goto out;
err = LEB_FREED_IDX;
} else {
dbg_gc("data LEB %d (free %d, dirty %d)",
lnum, lp->free, lp->dirty);
err = move_nodes(c, sleb);
if (err)
goto out;
err = gc_sync_wbufs(c);
if (err)
goto out;
err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0, 0, 0);
if (err)
goto out;
if (c->gc_lnum == -1) {
c->gc_lnum = lnum;
err = LEB_RETAINED;
} else {
err = ubifs_wbuf_sync_nolock(wbuf);
if (err)
goto out;
err = ubifs_leb_unmap(c, lnum);
if (err)
goto out;
err = LEB_FREED;
}
}
out:
ubifs_scan_destroy(sleb);
return err;
}
/**
* ubifs_garbage_collect - UBIFS garbage collector.
* @c: UBIFS file-system description object
* @anyway: do GC even if there are free LEBs
*
* This function does out-of-place garbage collection. The return codes are:
* o positive LEB number if the LEB has been freed and may be used;
* o %-EAGAIN if the caller has to run commit;
* o %-ENOSPC if GC failed to make any progress;
* o other negative error codes in case of other errors.
*
* Garbage collector writes data to the journal when GC'ing data LEBs, and just
* marking indexing nodes dirty when GC'ing indexing LEBs. Thus, at some point
* commit may be required. But commit cannot be run from inside GC, because the
* caller might be holding the commit lock, so %-EAGAIN is returned instead;
* And this error code means that the caller has to run commit, and re-run GC
* if there is still no free space.
*
* There are many reasons why this function may return %-EAGAIN:
* o the log is full and there is no space to write an LEB reference for
* @c->gc_lnum;
* o the journal is too large and exceeds size limitations;
* o GC moved indexing LEBs, but they can be used only after the commit;
* o the shrinker fails to find clean znodes to free and requests the commit;
* o etc.
*
* Note, if the file-system is close to be full, this function may return
* %-EAGAIN infinitely, so the caller has to limit amount of re-invocations of
* the function. E.g., this happens if the limits on the journal size are too
* tough and GC writes too much to the journal before an LEB is freed. This
* might also mean that the journal is too large, and the TNC becomes to big,
* so that the shrinker is constantly called, finds not clean znodes to free,
* and requests commit. Well, this may also happen if the journal is all right,
* but another kernel process consumes too much memory. Anyway, infinite
* %-EAGAIN may happen, but in some extreme/misconfiguration cases.
*/
int ubifs_garbage_collect(struct ubifs_info *c, int anyway)
{
int i, err, ret, min_space = c->dead_wm;
struct ubifs_lprops lp;
struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
ubifs_assert_cmt_locked(c);
if (ubifs_gc_should_commit(c))
return -EAGAIN;
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
if (c->ro_media) {
ret = -EROFS;
goto out_unlock;
}
/* We expect the write-buffer to be empty on entry */
ubifs_assert(!wbuf->used);
for (i = 0; ; i++) {
int space_before = c->leb_size - wbuf->offs - wbuf->used;
int space_after;
cond_resched();
/* Give the commit an opportunity to run */
if (ubifs_gc_should_commit(c)) {
ret = -EAGAIN;
break;
}
if (i > SOFT_LEBS_LIMIT && !list_empty(&c->idx_gc)) {
/*
* We've done enough iterations. Indexing LEBs were
* moved and will be available after the commit.
*/
dbg_gc("soft limit, some index LEBs GC'ed, -EAGAIN");
ubifs_commit_required(c);
ret = -EAGAIN;
break;
}
if (i > HARD_LEBS_LIMIT) {
/*
* We've moved too many LEBs and have not made
* progress, give up.
*/
dbg_gc("hard limit, -ENOSPC");
ret = -ENOSPC;
break;
}
/*
* Empty and freeable LEBs can turn up while we waited for
* the wbuf lock, or while we have been running GC. In that
* case, we should just return one of those instead of
* continuing to GC dirty LEBs. Hence we request
* 'ubifs_find_dirty_leb()' to return an empty LEB if it can.
*/
ret = ubifs_find_dirty_leb(c, &lp, min_space, anyway ? 0 : 1);
if (ret) {
if (ret == -ENOSPC)
dbg_gc("no more dirty LEBs");
break;
}
dbg_gc("found LEB %d: free %d, dirty %d, sum %d "
"(min. space %d)", lp.lnum, lp.free, lp.dirty,
lp.free + lp.dirty, min_space);
if (lp.free + lp.dirty == c->leb_size) {
/* An empty LEB was returned */
dbg_gc("LEB %d is free, return it", lp.lnum);
/*
* ubifs_find_dirty_leb() doesn't return freeable index
* LEBs.
*/
ubifs_assert(!(lp.flags & LPROPS_INDEX));
if (lp.free != c->leb_size) {
/*
* Write buffers must be sync'd before
* unmapping freeable LEBs, because one of them
* may contain data which obsoletes something
* in 'lp.pnum'.
*/
ret = gc_sync_wbufs(c);
if (ret)
goto out;
ret = ubifs_change_one_lp(c, lp.lnum,
c->leb_size, 0, 0, 0,
0);
if (ret)
goto out;
}
ret = ubifs_leb_unmap(c, lp.lnum);
if (ret)
goto out;
ret = lp.lnum;
break;
}
space_before = c->leb_size - wbuf->offs - wbuf->used;
if (wbuf->lnum == -1)
space_before = 0;
ret = ubifs_garbage_collect_leb(c, &lp);
if (ret < 0) {
if (ret == -EAGAIN || ret == -ENOSPC) {
/*
* These codes are not errors, so we have to
* return the LEB to lprops. But if the
* 'ubifs_return_leb()' function fails, its
* failure code is propagated to the caller
* instead of the original '-EAGAIN' or
* '-ENOSPC'.
*/
err = ubifs_return_leb(c, lp.lnum);
if (err)
ret = err;
break;
}
goto out;
}
if (ret == LEB_FREED) {
/* An LEB has been freed and is ready for use */
dbg_gc("LEB %d freed, return", lp.lnum);
ret = lp.lnum;
break;
}
if (ret == LEB_FREED_IDX) {
/*
* This was an indexing LEB and it cannot be
* immediately used. And instead of requesting the
* commit straight away, we try to garbage collect some
* more.
*/
dbg_gc("indexing LEB %d freed, continue", lp.lnum);
continue;
}
ubifs_assert(ret == LEB_RETAINED);
space_after = c->leb_size - wbuf->offs - wbuf->used;
dbg_gc("LEB %d retained, freed %d bytes", lp.lnum,
space_after - space_before);
if (space_after > space_before) {
/* GC makes progress, keep working */
min_space >>= 1;
if (min_space < c->dead_wm)
min_space = c->dead_wm;
continue;
}
dbg_gc("did not make progress");
/*
* GC moved an LEB bud have not done any progress. This means
* that the previous GC head LEB contained too few free space
* and the LEB which was GC'ed contained only large nodes which
* did not fit that space.
*
* We can do 2 things:
* 1. pick another LEB in a hope it'll contain a small node
* which will fit the space we have at the end of current GC
* head LEB, but there is no guarantee, so we try this out
* unless we have already been working for too long;
* 2. request an LEB with more dirty space, which will force
* 'ubifs_find_dirty_leb()' to start scanning the lprops
* table, instead of just picking one from the heap
* (previously it already picked the dirtiest LEB).
*/
if (i < SOFT_LEBS_LIMIT) {
dbg_gc("try again");
continue;
}
min_space <<= 1;
if (min_space > c->dark_wm)
min_space = c->dark_wm;
dbg_gc("set min. space to %d", min_space);
}
if (ret == -ENOSPC && !list_empty(&c->idx_gc)) {
dbg_gc("no space, some index LEBs GC'ed, -EAGAIN");
ubifs_commit_required(c);
ret = -EAGAIN;
}
err = ubifs_wbuf_sync_nolock(wbuf);
if (!err)
err = ubifs_leb_unmap(c, c->gc_lnum);
if (err) {
ret = err;
goto out;
}
out_unlock:
mutex_unlock(&wbuf->io_mutex);
return ret;
out:
ubifs_assert(ret < 0);
ubifs_assert(ret != -ENOSPC && ret != -EAGAIN);
ubifs_ro_mode(c, ret);
ubifs_wbuf_sync_nolock(wbuf);
mutex_unlock(&wbuf->io_mutex);
ubifs_return_leb(c, lp.lnum);
return ret;
}
/**
* ubifs_gc_start_commit - garbage collection at start of commit.
* @c: UBIFS file-system description object
*
* If a LEB has only dirty and free space, then we may safely unmap it and make
* it free. Note, we cannot do this with indexing LEBs because dirty space may
* correspond index nodes that are required for recovery. In that case, the
* LEB cannot be unmapped until after the next commit.
*
* This function returns %0 upon success and a negative error code upon failure.
*/
int ubifs_gc_start_commit(struct ubifs_info *c)
{
struct ubifs_gced_idx_leb *idx_gc;
const struct ubifs_lprops *lp;
int err = 0, flags;
ubifs_get_lprops(c);
/*
* Unmap (non-index) freeable LEBs. Note that recovery requires that all
* wbufs are sync'd before this, which is done in 'do_commit()'.
*/
while (1) {
lp = ubifs_fast_find_freeable(c);
if (unlikely(IS_ERR(lp))) {
err = PTR_ERR(lp);
goto out;
}
if (!lp)
break;
ubifs_assert(!(lp->flags & LPROPS_TAKEN));
ubifs_assert(!(lp->flags & LPROPS_INDEX));
err = ubifs_leb_unmap(c, lp->lnum);
if (err)
goto out;
lp = ubifs_change_lp(c, lp, c->leb_size, 0, lp->flags, 0);
if (unlikely(IS_ERR(lp))) {
err = PTR_ERR(lp);
goto out;
}
ubifs_assert(!(lp->flags & LPROPS_TAKEN));
ubifs_assert(!(lp->flags & LPROPS_INDEX));
}
/* Mark GC'd index LEBs OK to unmap after this commit finishes */
list_for_each_entry(idx_gc, &c->idx_gc, list)
idx_gc->unmap = 1;
/* Record index freeable LEBs for unmapping after commit */
while (1) {
lp = ubifs_fast_find_frdi_idx(c);
if (unlikely(IS_ERR(lp))) {
err = PTR_ERR(lp);
goto out;
}
if (!lp)
break;
idx_gc = kmalloc(sizeof(struct ubifs_gced_idx_leb), GFP_NOFS);
if (!idx_gc) {
err = -ENOMEM;
goto out;
}
ubifs_assert(!(lp->flags & LPROPS_TAKEN));
ubifs_assert(lp->flags & LPROPS_INDEX);
/* Don't release the LEB until after the next commit */
flags = (lp->flags | LPROPS_TAKEN) ^ LPROPS_INDEX;
lp = ubifs_change_lp(c, lp, c->leb_size, 0, flags, 1);
if (unlikely(IS_ERR(lp))) {
err = PTR_ERR(lp);
kfree(idx_gc);
goto out;
}
ubifs_assert(lp->flags & LPROPS_TAKEN);
ubifs_assert(!(lp->flags & LPROPS_INDEX));
idx_gc->lnum = lp->lnum;
idx_gc->unmap = 1;
list_add(&idx_gc->list, &c->idx_gc);
}
out:
ubifs_release_lprops(c);
return err;
}
/**
* ubifs_gc_end_commit - garbage collection at end of commit.
* @c: UBIFS file-system description object
*
* This function completes out-of-place garbage collection of index LEBs.
*/
int ubifs_gc_end_commit(struct ubifs_info *c)
{
struct ubifs_gced_idx_leb *idx_gc, *tmp;
struct ubifs_wbuf *wbuf;
int err = 0;
wbuf = &c->jheads[GCHD].wbuf;
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
list_for_each_entry_safe(idx_gc, tmp, &c->idx_gc, list)
if (idx_gc->unmap) {
dbg_gc("LEB %d", idx_gc->lnum);
err = ubifs_leb_unmap(c, idx_gc->lnum);
if (err)
goto out;
err = ubifs_change_one_lp(c, idx_gc->lnum, LPROPS_NC,
LPROPS_NC, 0, LPROPS_TAKEN, -1);
if (err)
goto out;
list_del(&idx_gc->list);
kfree(idx_gc);
}
out:
mutex_unlock(&wbuf->io_mutex);
return err;
}
/**
* ubifs_destroy_idx_gc - destroy idx_gc list.
* @c: UBIFS file-system description object
*
* This function destroys the idx_gc list. It is called when unmounting or
* remounting read-only so locks are not needed.
*/
void ubifs_destroy_idx_gc(struct ubifs_info *c)
{
while (!list_empty(&c->idx_gc)) {
struct ubifs_gced_idx_leb *idx_gc;
idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb,
list);
c->idx_gc_cnt -= 1;
list_del(&idx_gc->list);
kfree(idx_gc);
}
}
/**
* ubifs_get_idx_gc_leb - get a LEB from GC'd index LEB list.
* @c: UBIFS file-system description object
*
* Called during start commit so locks are not needed.
*/
int ubifs_get_idx_gc_leb(struct ubifs_info *c)
{
struct ubifs_gced_idx_leb *idx_gc;
int lnum;
if (list_empty(&c->idx_gc))
return -ENOSPC;
idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb, list);
lnum = idx_gc->lnum;
/* c->idx_gc_cnt is updated by the caller when lprops are updated */
list_del(&idx_gc->list);
kfree(idx_gc);
return lnum;
}

914
fs/ubifs/io.c Normal file
View File

@ -0,0 +1,914 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
* Copyright (C) 2006, 2007 University of Szeged, Hungary
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
* Zoltan Sogor
*/
/*
* This file implements UBIFS I/O subsystem which provides various I/O-related
* helper functions (reading/writing/checking/validating nodes) and implements
* write-buffering support. Write buffers help to save space which otherwise
* would have been wasted for padding to the nearest minimal I/O unit boundary.
* Instead, data first goes to the write-buffer and is flushed when the
* buffer is full or when it is not used for some time (by timer). This is
* similarto the mechanism is used by JFFS2.
*
* Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by
* mutexes defined inside these objects. Since sometimes upper-level code
* has to lock the write-buffer (e.g. journal space reservation code), many
* functions related to write-buffers have "nolock" suffix which means that the
* caller has to lock the write-buffer before calling this function.
*
* UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not
* aligned, UBIFS starts the next node from the aligned address, and the padded
* bytes may contain any rubbish. In other words, UBIFS does not put padding
* bytes in those small gaps. Common headers of nodes store real node lengths,
* not aligned lengths. Indexing nodes also store real lengths in branches.
*
* UBIFS uses padding when it pads to the next min. I/O unit. In this case it
* uses padding nodes or padding bytes, if the padding node does not fit.
*
* All UBIFS nodes are protected by CRC checksums and UBIFS checks all nodes
* every time they are read from the flash media.
*/
#include <linux/crc32.h>
#include "ubifs.h"
/**
* ubifs_check_node - check node.
* @c: UBIFS file-system description object
* @buf: node to check
* @lnum: logical eraseblock number
* @offs: offset within the logical eraseblock
* @quiet: print no messages
*
* This function checks node magic number and CRC checksum. This function also
* validates node length to prevent UBIFS from becoming crazy when an attacker
* feeds it a file-system image with incorrect nodes. For example, too large
* node length in the common header could cause UBIFS to read memory outside of
* allocated buffer when checking the CRC checksum.
*
* This function returns zero in case of success %-EUCLEAN in case of bad CRC
* or magic.
*/
int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
int offs, int quiet)
{
int err = -EINVAL, type, node_len;
uint32_t crc, node_crc, magic;
const struct ubifs_ch *ch = buf;
ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
ubifs_assert(!(offs & 7) && offs < c->leb_size);
magic = le32_to_cpu(ch->magic);
if (magic != UBIFS_NODE_MAGIC) {
if (!quiet)
ubifs_err("bad magic %#08x, expected %#08x",
magic, UBIFS_NODE_MAGIC);
err = -EUCLEAN;
goto out;
}
type = ch->node_type;
if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) {
if (!quiet)
ubifs_err("bad node type %d", type);
goto out;
}
node_len = le32_to_cpu(ch->len);
if (node_len + offs > c->leb_size)
goto out_len;
if (c->ranges[type].max_len == 0) {
if (node_len != c->ranges[type].len)
goto out_len;
} else if (node_len < c->ranges[type].min_len ||
node_len > c->ranges[type].max_len)
goto out_len;
crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
node_crc = le32_to_cpu(ch->crc);
if (crc != node_crc) {
if (!quiet)
ubifs_err("bad CRC: calculated %#08x, read %#08x",
crc, node_crc);
err = -EUCLEAN;
goto out;
}
return 0;
out_len:
if (!quiet)
ubifs_err("bad node length %d", node_len);
out:
if (!quiet) {
ubifs_err("bad node at LEB %d:%d", lnum, offs);
dbg_dump_node(c, buf);
dbg_dump_stack();
}
return err;
}
/**
* ubifs_pad - pad flash space.
* @c: UBIFS file-system description object
* @buf: buffer to put padding to
* @pad: how many bytes to pad
*
* The flash media obliges us to write only in chunks of %c->min_io_size and
* when we have to write less data we add padding node to the write-buffer and
* pad it to the next minimal I/O unit's boundary. Padding nodes help when the
* media is being scanned. If the amount of wasted space is not enough to fit a
* padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes
* pattern (%UBIFS_PADDING_BYTE).
*
* Padding nodes are also used to fill gaps when the "commit-in-gaps" method is
* used.
*/
void ubifs_pad(const struct ubifs_info *c, void *buf, int pad)
{
uint32_t crc;
ubifs_assert(pad >= 0 && !(pad & 7));
if (pad >= UBIFS_PAD_NODE_SZ) {
struct ubifs_ch *ch = buf;
struct ubifs_pad_node *pad_node = buf;
ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
ch->node_type = UBIFS_PAD_NODE;
ch->group_type = UBIFS_NO_NODE_GROUP;
ch->padding[0] = ch->padding[1] = 0;
ch->sqnum = 0;
ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ);
pad -= UBIFS_PAD_NODE_SZ;
pad_node->pad_len = cpu_to_le32(pad);
crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8);
ch->crc = cpu_to_le32(crc);
memset(buf + UBIFS_PAD_NODE_SZ, 0, pad);
} else if (pad > 0)
/* Too little space, padding node won't fit */
memset(buf, UBIFS_PADDING_BYTE, pad);
}
/**
* next_sqnum - get next sequence number.
* @c: UBIFS file-system description object
*/
static unsigned long long next_sqnum(struct ubifs_info *c)
{
unsigned long long sqnum;
spin_lock(&c->cnt_lock);
sqnum = ++c->max_sqnum;
spin_unlock(&c->cnt_lock);
if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) {
if (sqnum >= SQNUM_WATERMARK) {
ubifs_err("sequence number overflow %llu, end of life",
sqnum);
ubifs_ro_mode(c, -EINVAL);
}
ubifs_warn("running out of sequence numbers, end of life soon");
}
return sqnum;
}
/**
* ubifs_prepare_node - prepare node to be written to flash.
* @c: UBIFS file-system description object
* @node: the node to pad
* @len: node length
* @pad: if the buffer has to be padded
*
* This function prepares node at @node to be written to the media - it
* calculates node CRC, fills the common header, and adds proper padding up to
* the next minimum I/O unit if @pad is not zero.
*/
void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad)
{
uint32_t crc;
struct ubifs_ch *ch = node;
unsigned long long sqnum = next_sqnum(c);
ubifs_assert(len >= UBIFS_CH_SZ);
ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
ch->len = cpu_to_le32(len);
ch->group_type = UBIFS_NO_NODE_GROUP;
ch->sqnum = cpu_to_le64(sqnum);
ch->padding[0] = ch->padding[1] = 0;
crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
ch->crc = cpu_to_le32(crc);
if (pad) {
len = ALIGN(len, 8);
pad = ALIGN(len, c->min_io_size) - len;
ubifs_pad(c, node + len, pad);
}
}
/**
* ubifs_prep_grp_node - prepare node of a group to be written to flash.
* @c: UBIFS file-system description object
* @node: the node to pad
* @len: node length
* @last: indicates the last node of the group
*
* This function prepares node at @node to be written to the media - it
* calculates node CRC and fills the common header.
*/
void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last)
{
uint32_t crc;
struct ubifs_ch *ch = node;
unsigned long long sqnum = next_sqnum(c);
ubifs_assert(len >= UBIFS_CH_SZ);
ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
ch->len = cpu_to_le32(len);
if (last)
ch->group_type = UBIFS_LAST_OF_NODE_GROUP;
else
ch->group_type = UBIFS_IN_NODE_GROUP;
ch->sqnum = cpu_to_le64(sqnum);
ch->padding[0] = ch->padding[1] = 0;
crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
ch->crc = cpu_to_le32(crc);
}
/**
* wbuf_timer_callback - write-buffer timer callback function.
* @data: timer data (write-buffer descriptor)
*
* This function is called when the write-buffer timer expires.
*/
static void wbuf_timer_callback_nolock(unsigned long data)
{
struct ubifs_wbuf *wbuf = (struct ubifs_wbuf *)data;
wbuf->need_sync = 1;
wbuf->c->need_wbuf_sync = 1;
ubifs_wake_up_bgt(wbuf->c);
}
/**
* new_wbuf_timer - start new write-buffer timer.
* @wbuf: write-buffer descriptor
*/
static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
{
ubifs_assert(!timer_pending(&wbuf->timer));
if (!wbuf->timeout)
return;
wbuf->timer.expires = jiffies + wbuf->timeout;
add_timer(&wbuf->timer);
}
/**
* cancel_wbuf_timer - cancel write-buffer timer.
* @wbuf: write-buffer descriptor
*/
static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
{
/*
* If the syncer is waiting for the lock (from the background thread's
* context) and another task is changing write-buffer then the syncing
* should be canceled.
*/
wbuf->need_sync = 0;
del_timer(&wbuf->timer);
}
/**
* ubifs_wbuf_sync_nolock - synchronize write-buffer.
* @wbuf: write-buffer to synchronize
*
* This function synchronizes write-buffer @buf and returns zero in case of
* success or a negative error code in case of failure.
*/
int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf)
{
struct ubifs_info *c = wbuf->c;
int err, dirt;
cancel_wbuf_timer_nolock(wbuf);
if (!wbuf->used || wbuf->lnum == -1)
/* Write-buffer is empty or not seeked */
return 0;
dbg_io("LEB %d:%d, %d bytes",
wbuf->lnum, wbuf->offs, wbuf->used);
ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY));
ubifs_assert(!(wbuf->avail & 7));
ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size);
if (c->ro_media)
return -EROFS;
ubifs_pad(c, wbuf->buf + wbuf->used, wbuf->avail);
err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs,
c->min_io_size, wbuf->dtype);
if (err) {
ubifs_err("cannot write %d bytes to LEB %d:%d",
c->min_io_size, wbuf->lnum, wbuf->offs);
dbg_dump_stack();
return err;
}
dirt = wbuf->avail;
spin_lock(&wbuf->lock);
wbuf->offs += c->min_io_size;
wbuf->avail = c->min_io_size;
wbuf->used = 0;
wbuf->next_ino = 0;
spin_unlock(&wbuf->lock);
if (wbuf->sync_callback)
err = wbuf->sync_callback(c, wbuf->lnum,
c->leb_size - wbuf->offs, dirt);
return err;
}
/**
* ubifs_wbuf_seek_nolock - seek write-buffer.
* @wbuf: write-buffer
* @lnum: logical eraseblock number to seek to
* @offs: logical eraseblock offset to seek to
* @dtype: data type
*
* This function targets the write buffer to logical eraseblock @lnum:@offs.
* The write-buffer is synchronized if it is not empty. Returns zero in case of
* success and a negative error code in case of failure.
*/
int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs,
int dtype)
{
const struct ubifs_info *c = wbuf->c;
dbg_io("LEB %d:%d", lnum, offs);
ubifs_assert(lnum >= 0 && lnum < c->leb_cnt);
ubifs_assert(offs >= 0 && offs <= c->leb_size);
ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7));
ubifs_assert(lnum != wbuf->lnum);
if (wbuf->used > 0) {
int err = ubifs_wbuf_sync_nolock(wbuf);
if (err)
return err;
}
spin_lock(&wbuf->lock);
wbuf->lnum = lnum;
wbuf->offs = offs;
wbuf->avail = c->min_io_size;
wbuf->used = 0;
spin_unlock(&wbuf->lock);
wbuf->dtype = dtype;
return 0;
}
/**
* ubifs_bg_wbufs_sync - synchronize write-buffers.
* @c: UBIFS file-system description object
*
* This function is called by background thread to synchronize write-buffers.
* Returns zero in case of success and a negative error code in case of
* failure.
*/
int ubifs_bg_wbufs_sync(struct ubifs_info *c)
{
int err, i;
if (!c->need_wbuf_sync)
return 0;
c->need_wbuf_sync = 0;
if (c->ro_media) {
err = -EROFS;
goto out_timers;
}
dbg_io("synchronize");
for (i = 0; i < c->jhead_cnt; i++) {
struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
cond_resched();
/*
* If the mutex is locked then wbuf is being changed, so
* synchronization is not necessary.
*/
if (mutex_is_locked(&wbuf->io_mutex))
continue;
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
if (!wbuf->need_sync) {
mutex_unlock(&wbuf->io_mutex);
continue;
}
err = ubifs_wbuf_sync_nolock(wbuf);
mutex_unlock(&wbuf->io_mutex);
if (err) {
ubifs_err("cannot sync write-buffer, error %d", err);
ubifs_ro_mode(c, err);
goto out_timers;
}
}
return 0;
out_timers:
/* Cancel all timers to prevent repeated errors */
for (i = 0; i < c->jhead_cnt; i++) {
struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
cancel_wbuf_timer_nolock(wbuf);
mutex_unlock(&wbuf->io_mutex);
}
return err;
}
/**
* ubifs_wbuf_write_nolock - write data to flash via write-buffer.
* @wbuf: write-buffer
* @buf: node to write
* @len: node length
*
* This function writes data to flash via write-buffer @wbuf. This means that
* the last piece of the node won't reach the flash media immediately if it
* does not take whole minimal I/O unit. Instead, the node will sit in RAM
* until the write-buffer is synchronized (e.g., by timer).
*
* This function returns zero in case of success and a negative error code in
* case of failure. If the node cannot be written because there is no more
* space in this logical eraseblock, %-ENOSPC is returned.
*/
int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
{
struct ubifs_info *c = wbuf->c;
int err, written, n, aligned_len = ALIGN(len, 8), offs;
dbg_io("%d bytes (%s) to wbuf at LEB %d:%d", len,
dbg_ntype(((struct ubifs_ch *)buf)->node_type), wbuf->lnum,
wbuf->offs + wbuf->used);
ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt);
ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0);
ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size);
ubifs_assert(wbuf->avail > 0 && wbuf->avail <= c->min_io_size);
ubifs_assert(mutex_is_locked(&wbuf->io_mutex));
if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) {
err = -ENOSPC;
goto out;
}
cancel_wbuf_timer_nolock(wbuf);
if (c->ro_media)
return -EROFS;
if (aligned_len <= wbuf->avail) {
/*
* The node is not very large and fits entirely within
* write-buffer.
*/
memcpy(wbuf->buf + wbuf->used, buf, len);
if (aligned_len == wbuf->avail) {
dbg_io("flush wbuf to LEB %d:%d", wbuf->lnum,
wbuf->offs);
err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf,
wbuf->offs, c->min_io_size,
wbuf->dtype);
if (err)
goto out;
spin_lock(&wbuf->lock);
wbuf->offs += c->min_io_size;
wbuf->avail = c->min_io_size;
wbuf->used = 0;
wbuf->next_ino = 0;
spin_unlock(&wbuf->lock);
} else {
spin_lock(&wbuf->lock);
wbuf->avail -= aligned_len;
wbuf->used += aligned_len;
spin_unlock(&wbuf->lock);
}
goto exit;
}
/*
* The node is large enough and does not fit entirely within current
* minimal I/O unit. We have to fill and flush write-buffer and switch
* to the next min. I/O unit.
*/
dbg_io("flush wbuf to LEB %d:%d", wbuf->lnum, wbuf->offs);
memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail);
err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs,
c->min_io_size, wbuf->dtype);
if (err)
goto out;
offs = wbuf->offs + c->min_io_size;
len -= wbuf->avail;
aligned_len -= wbuf->avail;
written = wbuf->avail;
/*
* The remaining data may take more whole min. I/O units, so write the
* remains multiple to min. I/O unit size directly to the flash media.
* We align node length to 8-byte boundary because we anyway flash wbuf
* if the remaining space is less than 8 bytes.
*/
n = aligned_len >> c->min_io_shift;
if (n) {
n <<= c->min_io_shift;
dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, offs);
err = ubi_leb_write(c->ubi, wbuf->lnum, buf + written, offs, n,
wbuf->dtype);
if (err)
goto out;
offs += n;
aligned_len -= n;
len -= n;
written += n;
}
spin_lock(&wbuf->lock);
if (aligned_len)
/*
* And now we have what's left and what does not take whole
* min. I/O unit, so write it to the write-buffer and we are
* done.
*/
memcpy(wbuf->buf, buf + written, len);
wbuf->offs = offs;
wbuf->used = aligned_len;
wbuf->avail = c->min_io_size - aligned_len;
wbuf->next_ino = 0;
spin_unlock(&wbuf->lock);
exit:
if (wbuf->sync_callback) {
int free = c->leb_size - wbuf->offs - wbuf->used;
err = wbuf->sync_callback(c, wbuf->lnum, free, 0);
if (err)
goto out;
}
if (wbuf->used)
new_wbuf_timer_nolock(wbuf);
return 0;
out:
ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
len, wbuf->lnum, wbuf->offs, err);
dbg_dump_node(c, buf);
dbg_dump_stack();
dbg_dump_leb(c, wbuf->lnum);
return err;
}
/**
* ubifs_write_node - write node to the media.
* @c: UBIFS file-system description object
* @buf: the node to write
* @len: node length
* @lnum: logical eraseblock number
* @offs: offset within the logical eraseblock
* @dtype: node life-time hint (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
*
* This function automatically fills node magic number, assigns sequence
* number, and calculates node CRC checksum. The length of the @buf buffer has
* to be aligned to the minimal I/O unit size. This function automatically
* appends padding node and padding bytes if needed. Returns zero in case of
* success and a negative error code in case of failure.
*/
int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
int offs, int dtype)
{
int err, buf_len = ALIGN(len, c->min_io_size);
dbg_io("LEB %d:%d, %s, length %d (aligned %d)",
lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len,
buf_len);
ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size);
if (c->ro_media)
return -EROFS;
ubifs_prepare_node(c, buf, len, 1);
err = ubi_leb_write(c->ubi, lnum, buf, offs, buf_len, dtype);
if (err) {
ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
buf_len, lnum, offs, err);
dbg_dump_node(c, buf);
dbg_dump_stack();
}
return err;
}
/**
* ubifs_read_node_wbuf - read node from the media or write-buffer.
* @wbuf: wbuf to check for un-written data
* @buf: buffer to read to
* @type: node type
* @len: node length
* @lnum: logical eraseblock number
* @offs: offset within the logical eraseblock
*
* This function reads a node of known type and length, checks it and stores
* in @buf. If the node partially or fully sits in the write-buffer, this
* function takes data from the buffer, otherwise it reads the flash media.
* Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative
* error code in case of failure.
*/
int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len,
int lnum, int offs)
{
const struct ubifs_info *c = wbuf->c;
int err, rlen, overlap;
struct ubifs_ch *ch = buf;
dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
ubifs_assert(!(offs & 7) && offs < c->leb_size);
ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
spin_lock(&wbuf->lock);
overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs);
if (!overlap) {
/* We may safely unlock the write-buffer and read the data */
spin_unlock(&wbuf->lock);
return ubifs_read_node(c, buf, type, len, lnum, offs);
}
/* Don't read under wbuf */
rlen = wbuf->offs - offs;
if (rlen < 0)
rlen = 0;
/* Copy the rest from the write-buffer */
memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen);
spin_unlock(&wbuf->lock);
if (rlen > 0) {
/* Read everything that goes before write-buffer */
err = ubi_read(c->ubi, lnum, buf, offs, rlen);
if (err && err != -EBADMSG) {
ubifs_err("failed to read node %d from LEB %d:%d, "
"error %d", type, lnum, offs, err);
dbg_dump_stack();
return err;
}
}
if (type != ch->node_type) {
ubifs_err("bad node type (%d but expected %d)",
ch->node_type, type);
goto out;
}
err = ubifs_check_node(c, buf, lnum, offs, 0);
if (err) {
ubifs_err("expected node type %d", type);
return err;
}
rlen = le32_to_cpu(ch->len);
if (rlen != len) {
ubifs_err("bad node length %d, expected %d", rlen, len);
goto out;
}
return 0;
out:
ubifs_err("bad node at LEB %d:%d", lnum, offs);
dbg_dump_node(c, buf);
dbg_dump_stack();
return -EINVAL;
}
/**
* ubifs_read_node - read node.
* @c: UBIFS file-system description object
* @buf: buffer to read to
* @type: node type
* @len: node length (not aligned)
* @lnum: logical eraseblock number
* @offs: offset within the logical eraseblock
*
* This function reads a node of known type and and length, checks it and
* stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched
* and a negative error code in case of failure.
*/
int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
int lnum, int offs)
{
int err, l;
struct ubifs_ch *ch = buf;
dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size);
ubifs_assert(!(offs & 7) && offs < c->leb_size);
ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
err = ubi_read(c->ubi, lnum, buf, offs, len);
if (err && err != -EBADMSG) {
ubifs_err("cannot read node %d from LEB %d:%d, error %d",
type, lnum, offs, err);
return err;
}
if (type != ch->node_type) {
ubifs_err("bad node type (%d but expected %d)",
ch->node_type, type);
goto out;
}
err = ubifs_check_node(c, buf, lnum, offs, 0);
if (err) {
ubifs_err("expected node type %d", type);
return err;
}
l = le32_to_cpu(ch->len);
if (l != len) {
ubifs_err("bad node length %d, expected %d", l, len);
goto out;
}
return 0;
out:
ubifs_err("bad node at LEB %d:%d", lnum, offs);
dbg_dump_node(c, buf);
dbg_dump_stack();
return -EINVAL;
}
/**
* ubifs_wbuf_init - initialize write-buffer.
* @c: UBIFS file-system description object
* @wbuf: write-buffer to initialize
*
* This function initializes write buffer. Returns zero in case of success
* %-ENOMEM in case of failure.
*/
int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf)
{
size_t size;
wbuf->buf = kmalloc(c->min_io_size, GFP_KERNEL);
if (!wbuf->buf)
return -ENOMEM;
size = (c->min_io_size / UBIFS_CH_SZ + 1) * sizeof(ino_t);
wbuf->inodes = kmalloc(size, GFP_KERNEL);
if (!wbuf->inodes) {
kfree(wbuf->buf);
wbuf->buf = NULL;
return -ENOMEM;
}
wbuf->used = 0;
wbuf->lnum = wbuf->offs = -1;
wbuf->avail = c->min_io_size;
wbuf->dtype = UBI_UNKNOWN;
wbuf->sync_callback = NULL;
mutex_init(&wbuf->io_mutex);
spin_lock_init(&wbuf->lock);
wbuf->c = c;
init_timer(&wbuf->timer);
wbuf->timer.function = wbuf_timer_callback_nolock;
wbuf->timer.data = (unsigned long)wbuf;
wbuf->timeout = DEFAULT_WBUF_TIMEOUT;
wbuf->next_ino = 0;
return 0;
}
/**
* ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array.
* @wbuf: the write-buffer whereto add
* @inum: the inode number
*
* This function adds an inode number to the inode array of the write-buffer.
*/
void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum)
{
if (!wbuf->buf)
/* NOR flash or something similar */
return;
spin_lock(&wbuf->lock);
if (wbuf->used)
wbuf->inodes[wbuf->next_ino++] = inum;
spin_unlock(&wbuf->lock);
}
/**
* wbuf_has_ino - returns if the wbuf contains data from the inode.
* @wbuf: the write-buffer
* @inum: the inode number
*
* This function returns with %1 if the write-buffer contains some data from the
* given inode otherwise it returns with %0.
*/
static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum)
{
int i, ret = 0;
spin_lock(&wbuf->lock);
for (i = 0; i < wbuf->next_ino; i++)
if (inum == wbuf->inodes[i]) {
ret = 1;
break;
}
spin_unlock(&wbuf->lock);
return ret;
}
/**
* ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode.
* @c: UBIFS file-system description object
* @inode: inode to synchronize
*
* This function synchronizes write-buffers which contain nodes belonging to
* @inode. Returns zero in case of success and a negative error code in case of
* failure.
*/
int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode)
{
int i, err = 0;
for (i = 0; i < c->jhead_cnt; i++) {
struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
if (i == GCHD)
/*
* GC head is special, do not look at it. Even if the
* head contains something related to this inode, it is
* a _copy_ of corresponding on-flash node which sits
* somewhere else.
*/
continue;
if (!wbuf_has_ino(wbuf, inode->i_ino))
continue;
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
if (wbuf_has_ino(wbuf, inode->i_ino))
err = ubifs_wbuf_sync_nolock(wbuf);
mutex_unlock(&wbuf->io_mutex);
if (err) {
ubifs_ro_mode(c, err);
return err;
}
}
return 0;
}

204
fs/ubifs/ioctl.c Normal file
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@ -0,0 +1,204 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
* Copyright (C) 2006, 2007 University of Szeged, Hungary
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Zoltan Sogor
* Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/* This file implements EXT2-compatible extended attribute ioctl() calls */
#include <linux/compat.h>
#include <linux/smp_lock.h>
#include <linux/mount.h>
#include "ubifs.h"
/**
* ubifs_set_inode_flags - set VFS inode flags.
* @inode: VFS inode to set flags for
*
* This function propagates flags from UBIFS inode object to VFS inode object.
*/
void ubifs_set_inode_flags(struct inode *inode)
{
unsigned int flags = ubifs_inode(inode)->flags;
inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC);
if (flags & UBIFS_SYNC_FL)
inode->i_flags |= S_SYNC;
if (flags & UBIFS_APPEND_FL)
inode->i_flags |= S_APPEND;
if (flags & UBIFS_IMMUTABLE_FL)
inode->i_flags |= S_IMMUTABLE;
if (flags & UBIFS_DIRSYNC_FL)
inode->i_flags |= S_DIRSYNC;
}
/*
* ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
* @ioctl_flags: flags to convert
*
* This function convert ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
* (@UBIFS_COMPR_FL, etc).
*/
static int ioctl2ubifs(int ioctl_flags)
{
int ubifs_flags = 0;
if (ioctl_flags & FS_COMPR_FL)
ubifs_flags |= UBIFS_COMPR_FL;
if (ioctl_flags & FS_SYNC_FL)
ubifs_flags |= UBIFS_SYNC_FL;
if (ioctl_flags & FS_APPEND_FL)
ubifs_flags |= UBIFS_APPEND_FL;
if (ioctl_flags & FS_IMMUTABLE_FL)
ubifs_flags |= UBIFS_IMMUTABLE_FL;
if (ioctl_flags & FS_DIRSYNC_FL)
ubifs_flags |= UBIFS_DIRSYNC_FL;
return ubifs_flags;
}
/*
* ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
* @ubifs_flags: flags to convert
*
* This function convert UBIFS (@UBIFS_COMPR_FL, etc) to ioctl flags
* (@FS_COMPR_FL, etc).
*/
static int ubifs2ioctl(int ubifs_flags)
{
int ioctl_flags = 0;
if (ubifs_flags & UBIFS_COMPR_FL)
ioctl_flags |= FS_COMPR_FL;
if (ubifs_flags & UBIFS_SYNC_FL)
ioctl_flags |= FS_SYNC_FL;
if (ubifs_flags & UBIFS_APPEND_FL)
ioctl_flags |= FS_APPEND_FL;
if (ubifs_flags & UBIFS_IMMUTABLE_FL)
ioctl_flags |= FS_IMMUTABLE_FL;
if (ubifs_flags & UBIFS_DIRSYNC_FL)
ioctl_flags |= FS_DIRSYNC_FL;
return ioctl_flags;
}
static int setflags(struct inode *inode, int flags)
{
int oldflags, err, release;
struct ubifs_inode *ui = ubifs_inode(inode);
struct ubifs_info *c = inode->i_sb->s_fs_info;
struct ubifs_budget_req req = { .dirtied_ino = 1,
.dirtied_ino_d = ui->data_len };
err = ubifs_budget_space(c, &req);
if (err)
return err;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*/
mutex_lock(&ui->ui_mutex);
oldflags = ubifs2ioctl(ui->flags);
if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
goto out_unlock;
}
}
ui->flags = ioctl2ubifs(flags);
ubifs_set_inode_flags(inode);
inode->i_ctime = ubifs_current_time(inode);
release = ui->dirty;
mark_inode_dirty_sync(inode);
mutex_unlock(&ui->ui_mutex);
if (release)
ubifs_release_budget(c, &req);
if (IS_SYNC(inode))
err = write_inode_now(inode, 1);
return err;
out_unlock:
ubifs_err("can't modify inode %lu attributes", inode->i_ino);
mutex_unlock(&ui->ui_mutex);
ubifs_release_budget(c, &req);
return err;
}
long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int flags, err;
struct inode *inode = file->f_path.dentry->d_inode;
switch (cmd) {
case FS_IOC_GETFLAGS:
flags = ubifs2ioctl(ubifs_inode(inode)->flags);
return put_user(flags, (int __user *) arg);
case FS_IOC_SETFLAGS: {
if (IS_RDONLY(inode))
return -EROFS;
if (!is_owner_or_cap(inode))
return -EACCES;
if (get_user(flags, (int __user *) arg))
return -EFAULT;
if (!S_ISDIR(inode->i_mode))
flags &= ~FS_DIRSYNC_FL;
/*
* Make sure the file-system is read-write and make sure it
* will not become read-only while we are changing the flags.
*/
err = mnt_want_write(file->f_path.mnt);
if (err)
return err;
err = setflags(inode, flags);
mnt_drop_write(file->f_path.mnt);
return err;
}
default:
return -ENOTTY;
}
}
#ifdef CONFIG_COMPAT
long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case FS_IOC32_GETFLAGS:
cmd = FS_IOC_GETFLAGS;
break;
case FS_IOC32_SETFLAGS:
cmd = FS_IOC_SETFLAGS;
break;
default:
return -ENOIOCTLCMD;
}
return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
#endif

1387
fs/ubifs/journal.c Normal file
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533
fs/ubifs/key.h Normal file
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@ -0,0 +1,533 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/*
* This header contains various key-related definitions and helper function.
* UBIFS allows several key schemes, so we access key fields only via these
* helpers. At the moment only one key scheme is supported.
*
* Simple key scheme
* ~~~~~~~~~~~~~~~~~
*
* Keys are 64-bits long. First 32-bits are inode number (parent inode number
* in case of direntry key). Next 3 bits are node type. The last 29 bits are
* 4KiB offset in case of inode node, and direntry hash in case of a direntry
* node. We use "r5" hash borrowed from reiserfs.
*/
#ifndef __UBIFS_KEY_H__
#define __UBIFS_KEY_H__
/**
* key_r5_hash - R5 hash function (borrowed from reiserfs).
* @s: direntry name
* @len: name length
*/
static inline uint32_t key_r5_hash(const char *s, int len)
{
uint32_t a = 0;
const signed char *str = (const signed char *)s;
while (*str) {
a += *str << 4;
a += *str >> 4;
a *= 11;
str++;
}
a &= UBIFS_S_KEY_HASH_MASK;
/*
* We use hash values as offset in directories, so values %0 and %1 are
* reserved for "." and "..". %2 is reserved for "end of readdir"
* marker.
*/
if (unlikely(a >= 0 && a <= 2))
a += 3;
return a;
}
/**
* key_test_hash - testing hash function.
* @str: direntry name
* @len: name length
*/
static inline uint32_t key_test_hash(const char *str, int len)
{
uint32_t a = 0;
len = min_t(uint32_t, len, 4);
memcpy(&a, str, len);
a &= UBIFS_S_KEY_HASH_MASK;
if (unlikely(a >= 0 && a <= 2))
a += 3;
return a;
}
/**
* ino_key_init - initialize inode key.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: inode number
*/
static inline void ino_key_init(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum)
{
key->u32[0] = inum;
key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS;
}
/**
* ino_key_init_flash - initialize on-flash inode key.
* @c: UBIFS file-system description object
* @k: key to initialize
* @inum: inode number
*/
static inline void ino_key_init_flash(const struct ubifs_info *c, void *k,
ino_t inum)
{
union ubifs_key *key = k;
key->j32[0] = cpu_to_le32(inum);
key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS);
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
}
/**
* lowest_ino_key - get the lowest possible inode key.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: inode number
*/
static inline void lowest_ino_key(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum)
{
key->u32[0] = inum;
key->u32[1] = 0;
}
/**
* highest_ino_key - get the highest possible inode key.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: inode number
*/
static inline void highest_ino_key(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum)
{
key->u32[0] = inum;
key->u32[1] = 0xffffffff;
}
/**
* dent_key_init - initialize directory entry key.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: parent inode number
* @nm: direntry name and length
*/
static inline void dent_key_init(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum,
const struct qstr *nm)
{
uint32_t hash = c->key_hash(nm->name, nm->len);
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
key->u32[0] = inum;
key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
}
/**
* dent_key_init_hash - initialize directory entry key without re-calculating
* hash function.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: parent inode number
* @hash: direntry name hash
*/
static inline void dent_key_init_hash(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum,
uint32_t hash)
{
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
key->u32[0] = inum;
key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
}
/**
* dent_key_init_flash - initialize on-flash directory entry key.
* @c: UBIFS file-system description object
* @k: key to initialize
* @inum: parent inode number
* @nm: direntry name and length
*/
static inline void dent_key_init_flash(const struct ubifs_info *c, void *k,
ino_t inum, const struct qstr *nm)
{
union ubifs_key *key = k;
uint32_t hash = c->key_hash(nm->name, nm->len);
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
key->j32[0] = cpu_to_le32(inum);
key->j32[1] = cpu_to_le32(hash |
(UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS));
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
}
/**
* lowest_dent_key - get the lowest possible directory entry key.
* @c: UBIFS file-system description object
* @key: where to store the lowest key
* @inum: parent inode number
*/
static inline void lowest_dent_key(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum)
{
key->u32[0] = inum;
key->u32[1] = UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS;
}
/**
* xent_key_init - initialize extended attribute entry key.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: host inode number
* @nm: extended attribute entry name and length
*/
static inline void xent_key_init(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum,
const struct qstr *nm)
{
uint32_t hash = c->key_hash(nm->name, nm->len);
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
key->u32[0] = inum;
key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
}
/**
* xent_key_init_hash - initialize extended attribute entry key without
* re-calculating hash function.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: host inode number
* @hash: extended attribute entry name hash
*/
static inline void xent_key_init_hash(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum,
uint32_t hash)
{
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
key->u32[0] = inum;
key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
}
/**
* xent_key_init_flash - initialize on-flash extended attribute entry key.
* @c: UBIFS file-system description object
* @k: key to initialize
* @inum: host inode number
* @nm: extended attribute entry name and length
*/
static inline void xent_key_init_flash(const struct ubifs_info *c, void *k,
ino_t inum, const struct qstr *nm)
{
union ubifs_key *key = k;
uint32_t hash = c->key_hash(nm->name, nm->len);
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
key->j32[0] = cpu_to_le32(inum);
key->j32[1] = cpu_to_le32(hash |
(UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS));
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
}
/**
* lowest_xent_key - get the lowest possible extended attribute entry key.
* @c: UBIFS file-system description object
* @key: where to store the lowest key
* @inum: host inode number
*/
static inline void lowest_xent_key(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum)
{
key->u32[0] = inum;
key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS;
}
/**
* data_key_init - initialize data key.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: inode number
* @block: block number
*/
static inline void data_key_init(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum,
unsigned int block)
{
ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
key->u32[0] = inum;
key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS);
}
/**
* data_key_init_flash - initialize on-flash data key.
* @c: UBIFS file-system description object
* @k: key to initialize
* @inum: inode number
* @block: block number
*/
static inline void data_key_init_flash(const struct ubifs_info *c, void *k,
ino_t inum, unsigned int block)
{
union ubifs_key *key = k;
ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
key->j32[0] = cpu_to_le32(inum);
key->j32[1] = cpu_to_le32(block |
(UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS));
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
}
/**
* trun_key_init - initialize truncation node key.
* @c: UBIFS file-system description object
* @key: key to initialize
* @inum: inode number
*
* Note, UBIFS does not have truncation keys on the media and this function is
* only used for purposes of replay.
*/
static inline void trun_key_init(const struct ubifs_info *c,
union ubifs_key *key, ino_t inum)
{
key->u32[0] = inum;
key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS;
}
/**
* key_type - get key type.
* @c: UBIFS file-system description object
* @key: key to get type of
*/
static inline int key_type(const struct ubifs_info *c,
const union ubifs_key *key)
{
return key->u32[1] >> UBIFS_S_KEY_BLOCK_BITS;
}
/**
* key_type_flash - get type of a on-flash formatted key.
* @c: UBIFS file-system description object
* @k: key to get type of
*/
static inline int key_type_flash(const struct ubifs_info *c, const void *k)
{
const union ubifs_key *key = k;
return le32_to_cpu(key->u32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
}
/**
* key_inum - fetch inode number from key.
* @c: UBIFS file-system description object
* @k: key to fetch inode number from
*/
static inline ino_t key_inum(const struct ubifs_info *c, const void *k)
{
const union ubifs_key *key = k;
return key->u32[0];
}
/**
* key_inum_flash - fetch inode number from an on-flash formatted key.
* @c: UBIFS file-system description object
* @k: key to fetch inode number from
*/
static inline ino_t key_inum_flash(const struct ubifs_info *c, const void *k)
{
const union ubifs_key *key = k;
return le32_to_cpu(key->j32[0]);
}
/**
* key_hash - get directory entry hash.
* @c: UBIFS file-system description object
* @key: the key to get hash from
*/
static inline int key_hash(const struct ubifs_info *c,
const union ubifs_key *key)
{
return key->u32[1] & UBIFS_S_KEY_HASH_MASK;
}
/**
* key_hash_flash - get directory entry hash from an on-flash formatted key.
* @c: UBIFS file-system description object
* @k: the key to get hash from
*/
static inline int key_hash_flash(const struct ubifs_info *c, const void *k)
{
const union ubifs_key *key = k;
return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_HASH_MASK;
}
/**
* key_block - get data block number.
* @c: UBIFS file-system description object
* @key: the key to get the block number from
*/
static inline unsigned int key_block(const struct ubifs_info *c,
const union ubifs_key *key)
{
return key->u32[1] & UBIFS_S_KEY_BLOCK_MASK;
}
/**
* key_block_flash - get data block number from an on-flash formatted key.
* @c: UBIFS file-system description object
* @k: the key to get the block number from
*/
static inline unsigned int key_block_flash(const struct ubifs_info *c,
const void *k)
{
const union ubifs_key *key = k;
return le32_to_cpu(key->u32[1]) & UBIFS_S_KEY_BLOCK_MASK;
}
/**
* key_read - transform a key to in-memory format.
* @c: UBIFS file-system description object
* @from: the key to transform
* @to: the key to store the result
*/
static inline void key_read(const struct ubifs_info *c, const void *from,
union ubifs_key *to)
{
const union ubifs_key *f = from;
to->u32[0] = le32_to_cpu(f->j32[0]);
to->u32[1] = le32_to_cpu(f->j32[1]);
}
/**
* key_write - transform a key from in-memory format.
* @c: UBIFS file-system description object
* @from: the key to transform
* @to: the key to store the result
*/
static inline void key_write(const struct ubifs_info *c,
const union ubifs_key *from, void *to)
{
union ubifs_key *t = to;
t->j32[0] = cpu_to_le32(from->u32[0]);
t->j32[1] = cpu_to_le32(from->u32[1]);
memset(to + 8, 0, UBIFS_MAX_KEY_LEN - 8);
}
/**
* key_write_idx - transform a key from in-memory format for the index.
* @c: UBIFS file-system description object
* @from: the key to transform
* @to: the key to store the result
*/
static inline void key_write_idx(const struct ubifs_info *c,
const union ubifs_key *from, void *to)
{
union ubifs_key *t = to;
t->j32[0] = cpu_to_le32(from->u32[0]);
t->j32[1] = cpu_to_le32(from->u32[1]);
}
/**
* key_copy - copy a key.
* @c: UBIFS file-system description object
* @from: the key to copy from
* @to: the key to copy to
*/
static inline void key_copy(const struct ubifs_info *c,
const union ubifs_key *from, union ubifs_key *to)
{
to->u64[0] = from->u64[0];
}
/**
* keys_cmp - compare keys.
* @c: UBIFS file-system description object
* @key1: the first key to compare
* @key2: the second key to compare
*
* This function compares 2 keys and returns %-1 if @key1 is less than
* @key2, 0 if the keys are equivalent and %1 if @key1 is greater than @key2.
*/
static inline int keys_cmp(const struct ubifs_info *c,
const union ubifs_key *key1,
const union ubifs_key *key2)
{
if (key1->u32[0] < key2->u32[0])
return -1;
if (key1->u32[0] > key2->u32[0])
return 1;
if (key1->u32[1] < key2->u32[1])
return -1;
if (key1->u32[1] > key2->u32[1])
return 1;
return 0;
}
/**
* is_hash_key - is a key vulnerable to hash collisions.
* @c: UBIFS file-system description object
* @key: key
*
* This function returns %1 if @key is a hashed key or %0 otherwise.
*/
static inline int is_hash_key(const struct ubifs_info *c,
const union ubifs_key *key)
{
int type = key_type(c, key);
return type == UBIFS_DENT_KEY || type == UBIFS_XENT_KEY;
}
/**
* key_max_inode_size - get maximum file size allowed by current key format.
* @c: UBIFS file-system description object
*/
static inline unsigned long long key_max_inode_size(const struct ubifs_info *c)
{
switch (c->key_fmt) {
case UBIFS_SIMPLE_KEY_FMT:
return (1ULL << UBIFS_S_KEY_BLOCK_BITS) * UBIFS_BLOCK_SIZE;
default:
return 0;
}
}
#endif /* !__UBIFS_KEY_H__ */

805
fs/ubifs/log.c Normal file
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@ -0,0 +1,805 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/*
* This file is a part of UBIFS journal implementation and contains various
* functions which manipulate the log. The log is a fixed area on the flash
* which does not contain any data but refers to buds. The log is a part of the
* journal.
*/
#include "ubifs.h"
#ifdef CONFIG_UBIFS_FS_DEBUG
static int dbg_check_bud_bytes(struct ubifs_info *c);
#else
#define dbg_check_bud_bytes(c) 0
#endif
/**
* ubifs_search_bud - search bud LEB.
* @c: UBIFS file-system description object
* @lnum: logical eraseblock number to search
*
* This function searches bud LEB @lnum. Returns bud description object in case
* of success and %NULL if there is no bud with this LEB number.
*/
struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum)
{
struct rb_node *p;
struct ubifs_bud *bud;
spin_lock(&c->buds_lock);
p = c->buds.rb_node;
while (p) {
bud = rb_entry(p, struct ubifs_bud, rb);
if (lnum < bud->lnum)
p = p->rb_left;
else if (lnum > bud->lnum)
p = p->rb_right;
else {
spin_unlock(&c->buds_lock);
return bud;
}
}
spin_unlock(&c->buds_lock);
return NULL;
}
/**
* ubifs_get_wbuf - get the wbuf associated with a LEB, if there is one.
* @c: UBIFS file-system description object
* @lnum: logical eraseblock number to search
*
* This functions returns the wbuf for @lnum or %NULL if there is not one.
*/
struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum)
{
struct rb_node *p;
struct ubifs_bud *bud;
int jhead;
if (!c->jheads)
return NULL;
spin_lock(&c->buds_lock);
p = c->buds.rb_node;
while (p) {
bud = rb_entry(p, struct ubifs_bud, rb);
if (lnum < bud->lnum)
p = p->rb_left;
else if (lnum > bud->lnum)
p = p->rb_right;
else {
jhead = bud->jhead;
spin_unlock(&c->buds_lock);
return &c->jheads[jhead].wbuf;
}
}
spin_unlock(&c->buds_lock);
return NULL;
}
/**
* next_log_lnum - switch to the next log LEB.
* @c: UBIFS file-system description object
* @lnum: current log LEB
*/
static inline int next_log_lnum(const struct ubifs_info *c, int lnum)
{
lnum += 1;
if (lnum > c->log_last)
lnum = UBIFS_LOG_LNUM;
return lnum;
}
/**
* empty_log_bytes - calculate amount of empty space in the log.
* @c: UBIFS file-system description object
*/
static inline long long empty_log_bytes(const struct ubifs_info *c)
{
long long h, t;
h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs;
t = (long long)c->ltail_lnum * c->leb_size;
if (h >= t)
return c->log_bytes - h + t;
else
return t - h;
}
/**
* ubifs_add_bud - add bud LEB to the tree of buds and its journal head list.
* @c: UBIFS file-system description object
* @bud: the bud to add
*/
void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
{
struct rb_node **p, *parent = NULL;
struct ubifs_bud *b;
struct ubifs_jhead *jhead;
spin_lock(&c->buds_lock);
p = &c->buds.rb_node;
while (*p) {
parent = *p;
b = rb_entry(parent, struct ubifs_bud, rb);
ubifs_assert(bud->lnum != b->lnum);
if (bud->lnum < b->lnum)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&bud->rb, parent, p);
rb_insert_color(&bud->rb, &c->buds);
if (c->jheads) {
jhead = &c->jheads[bud->jhead];
list_add_tail(&bud->list, &jhead->buds_list);
} else
ubifs_assert(c->replaying && (c->vfs_sb->s_flags & MS_RDONLY));
/*
* Note, although this is a new bud, we anyway account this space now,
* before any data has been written to it, because this is about to
* guarantee fixed mount time, and this bud will anyway be read and
* scanned.
*/
c->bud_bytes += c->leb_size - bud->start;
dbg_log("LEB %d:%d, jhead %d, bud_bytes %lld", bud->lnum,
bud->start, bud->jhead, c->bud_bytes);
spin_unlock(&c->buds_lock);
}
/**
* ubifs_create_buds_lists - create journal head buds lists for remount rw.
* @c: UBIFS file-system description object
*/
void ubifs_create_buds_lists(struct ubifs_info *c)
{
struct rb_node *p;
spin_lock(&c->buds_lock);
p = rb_first(&c->buds);
while (p) {
struct ubifs_bud *bud = rb_entry(p, struct ubifs_bud, rb);
struct ubifs_jhead *jhead = &c->jheads[bud->jhead];
list_add_tail(&bud->list, &jhead->buds_list);
p = rb_next(p);
}
spin_unlock(&c->buds_lock);
}
/**
* ubifs_add_bud_to_log - add a new bud to the log.
* @c: UBIFS file-system description object
* @jhead: journal head the bud belongs to
* @lnum: LEB number of the bud
* @offs: starting offset of the bud
*
* This function writes reference node for the new bud LEB @lnum it to the log,
* and adds it to the buds tress. It also makes sure that log size does not
* exceed the 'c->max_bud_bytes' limit. Returns zero in case of success,
* %-EAGAIN if commit is required, and a negative error codes in case of
* failure.
*/
int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
{
int err;
struct ubifs_bud *bud;
struct ubifs_ref_node *ref;
bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS);
if (!bud)
return -ENOMEM;
ref = kzalloc(c->ref_node_alsz, GFP_NOFS);
if (!ref) {
kfree(bud);
return -ENOMEM;
}
mutex_lock(&c->log_mutex);
if (c->ro_media) {
err = -EROFS;
goto out_unlock;
}
/* Make sure we have enough space in the log */
if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) {
dbg_log("not enough log space - %lld, required %d",
empty_log_bytes(c), c->min_log_bytes);
ubifs_commit_required(c);
err = -EAGAIN;
goto out_unlock;
}
/*
* Make sure the the amount of space in buds will not exceed
* 'c->max_bud_bytes' limit, because we want to guarantee mount time
* limits.
*
* It is not necessary to hold @c->buds_lock when reading @c->bud_bytes
* because we are holding @c->log_mutex. All @c->bud_bytes take place
* when both @c->log_mutex and @c->bud_bytes are locked.
*/
if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) {
dbg_log("bud bytes %lld (%lld max), require commit",
c->bud_bytes, c->max_bud_bytes);
ubifs_commit_required(c);
err = -EAGAIN;
goto out_unlock;
}
/*
* If the journal is full enough - start background commit. Note, it is
* OK to read 'c->cmt_state' without spinlock because integer reads
* are atomic in the kernel.
*/
if (c->bud_bytes >= c->bg_bud_bytes &&
c->cmt_state == COMMIT_RESTING) {
dbg_log("bud bytes %lld (%lld max), initiate BG commit",
c->bud_bytes, c->max_bud_bytes);
ubifs_request_bg_commit(c);
}
bud->lnum = lnum;
bud->start = offs;
bud->jhead = jhead;
ref->ch.node_type = UBIFS_REF_NODE;
ref->lnum = cpu_to_le32(bud->lnum);
ref->offs = cpu_to_le32(bud->start);
ref->jhead = cpu_to_le32(jhead);
if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
c->lhead_offs = 0;
}
if (c->lhead_offs == 0) {
/* Must ensure next log LEB has been unmapped */
err = ubifs_leb_unmap(c, c->lhead_lnum);
if (err)
goto out_unlock;
}
if (bud->start == 0) {
/*
* Before writing the LEB reference which refers an empty LEB
* to the log, we have to make sure it is mapped, because
* otherwise we'd risk to refer an LEB with garbage in case of
* an unclean reboot, because the target LEB might have been
* unmapped, but not yet physically erased.
*/
err = ubi_leb_map(c->ubi, bud->lnum, UBI_SHORTTERM);
if (err)
goto out_unlock;
}
dbg_log("write ref LEB %d:%d",
c->lhead_lnum, c->lhead_offs);
err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum,
c->lhead_offs, UBI_SHORTTERM);
if (err)
goto out_unlock;
c->lhead_offs += c->ref_node_alsz;
ubifs_add_bud(c, bud);
mutex_unlock(&c->log_mutex);
kfree(ref);
return 0;
out_unlock:
mutex_unlock(&c->log_mutex);
kfree(ref);
kfree(bud);
return err;
}
/**
* remove_buds - remove used buds.
* @c: UBIFS file-system description object
*
* This function removes use buds from the buds tree. It does not remove the
* buds which are pointed to by journal heads.
*/
static void remove_buds(struct ubifs_info *c)
{
struct rb_node *p;
ubifs_assert(list_empty(&c->old_buds));
c->cmt_bud_bytes = 0;
spin_lock(&c->buds_lock);
p = rb_first(&c->buds);
while (p) {
struct rb_node *p1 = p;
struct ubifs_bud *bud;
struct ubifs_wbuf *wbuf;
p = rb_next(p);
bud = rb_entry(p1, struct ubifs_bud, rb);
wbuf = &c->jheads[bud->jhead].wbuf;
if (wbuf->lnum == bud->lnum) {
/*
* Do not remove buds which are pointed to by journal
* heads (non-closed buds).
*/
c->cmt_bud_bytes += wbuf->offs - bud->start;
dbg_log("preserve %d:%d, jhead %d, bud bytes %d, "
"cmt_bud_bytes %lld", bud->lnum, bud->start,
bud->jhead, wbuf->offs - bud->start,
c->cmt_bud_bytes);
bud->start = wbuf->offs;
} else {
c->cmt_bud_bytes += c->leb_size - bud->start;
dbg_log("remove %d:%d, jhead %d, bud bytes %d, "
"cmt_bud_bytes %lld", bud->lnum, bud->start,
bud->jhead, c->leb_size - bud->start,
c->cmt_bud_bytes);
rb_erase(p1, &c->buds);
list_del(&bud->list);
/*
* If the commit does not finish, the recovery will need
* to replay the journal, in which case the old buds
* must be unchanged. Do not release them until post
* commit i.e. do not allow them to be garbage
* collected.
*/
list_add(&bud->list, &c->old_buds);
}
}
spin_unlock(&c->buds_lock);
}
/**
* ubifs_log_start_commit - start commit.
* @c: UBIFS file-system description object
* @ltail_lnum: return new log tail LEB number
*
* The commit operation starts with writing "commit start" node to the log and
* reference nodes for all journal heads which will define new journal after
* the commit has been finished. The commit start and reference nodes are
* written in one go to the nearest empty log LEB (hence, when commit is
* finished UBIFS may safely unmap all the previous log LEBs). This function
* returns zero in case of success and a negative error code in case of
* failure.
*/
int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
{
void *buf;
struct ubifs_cs_node *cs;
struct ubifs_ref_node *ref;
int err, i, max_len, len;
err = dbg_check_bud_bytes(c);
if (err)
return err;
max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
max_len = ALIGN(max_len, c->min_io_size);
buf = cs = kmalloc(max_len, GFP_NOFS);
if (!buf)
return -ENOMEM;
cs->ch.node_type = UBIFS_CS_NODE;
cs->cmt_no = cpu_to_le64(c->cmt_no + 1);
ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);
/*
* Note, we do not lock 'c->log_mutex' because this is the commit start
* phase and we are exclusively using the log. And we do not lock
* write-buffer because nobody can write to the file-system at this
* phase.
*/
len = UBIFS_CS_NODE_SZ;
for (i = 0; i < c->jhead_cnt; i++) {
int lnum = c->jheads[i].wbuf.lnum;
int offs = c->jheads[i].wbuf.offs;
if (lnum == -1 || offs == c->leb_size)
continue;
dbg_log("add ref to LEB %d:%d for jhead %d", lnum, offs, i);
ref = buf + len;
ref->ch.node_type = UBIFS_REF_NODE;
ref->lnum = cpu_to_le32(lnum);
ref->offs = cpu_to_le32(offs);
ref->jhead = cpu_to_le32(i);
ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
len += UBIFS_REF_NODE_SZ;
}
ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);
/* Switch to the next log LEB */
if (c->lhead_offs) {
c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
c->lhead_offs = 0;
}
if (c->lhead_offs == 0) {
/* Must ensure next LEB has been unmapped */
err = ubifs_leb_unmap(c, c->lhead_lnum);
if (err)
goto out;
}
len = ALIGN(len, c->min_io_size);
dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len, UBI_SHORTTERM);
if (err)
goto out;
*ltail_lnum = c->lhead_lnum;
c->lhead_offs += len;
if (c->lhead_offs == c->leb_size) {
c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
c->lhead_offs = 0;
}
remove_buds(c);
/*
* We have started the commit and now users may use the rest of the log
* for new writes.
*/
c->min_log_bytes = 0;
out:
kfree(buf);
return err;
}
/**
* ubifs_log_end_commit - end commit.
* @c: UBIFS file-system description object
* @ltail_lnum: new log tail LEB number
*
* This function is called on when the commit operation was finished. It
* moves log tail to new position and unmaps LEBs which contain obsolete data.
* Returns zero in case of success and a negative error code in case of
* failure.
*/
int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
{
int err;
/*
* At this phase we have to lock 'c->log_mutex' because UBIFS allows FS
* writes during commit. Its only short "commit" start phase when
* writers are blocked.
*/
mutex_lock(&c->log_mutex);
dbg_log("old tail was LEB %d:0, new tail is LEB %d:0",
c->ltail_lnum, ltail_lnum);
c->ltail_lnum = ltail_lnum;
/*
* The commit is finished and from now on it must be guaranteed that
* there is always enough space for the next commit.
*/
c->min_log_bytes = c->leb_size;
spin_lock(&c->buds_lock);
c->bud_bytes -= c->cmt_bud_bytes;
spin_unlock(&c->buds_lock);
err = dbg_check_bud_bytes(c);
mutex_unlock(&c->log_mutex);
return err;
}
/**
* ubifs_log_post_commit - things to do after commit is completed.
* @c: UBIFS file-system description object
* @old_ltail_lnum: old log tail LEB number
*
* Release buds only after commit is completed, because they must be unchanged
* if recovery is needed.
*
* Unmap log LEBs only after commit is completed, because they may be needed for
* recovery.
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
{
int lnum, err = 0;
while (!list_empty(&c->old_buds)) {
struct ubifs_bud *bud;
bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
err = ubifs_return_leb(c, bud->lnum);
if (err)
return err;
list_del(&bud->list);
kfree(bud);
}
mutex_lock(&c->log_mutex);
for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
lnum = next_log_lnum(c, lnum)) {
dbg_log("unmap log LEB %d", lnum);
err = ubifs_leb_unmap(c, lnum);
if (err)
goto out;
}
out:
mutex_unlock(&c->log_mutex);
return err;
}
/**
* struct done_ref - references that have been done.
* @rb: rb-tree node
* @lnum: LEB number
*/
struct done_ref {
struct rb_node rb;
int lnum;
};
/**
* done_already - determine if a reference has been done already.
* @done_tree: rb-tree to store references that have been done
* @lnum: LEB number of reference
*
* This function returns %1 if the reference has been done, %0 if not, otherwise
* a negative error code is returned.
*/
static int done_already(struct rb_root *done_tree, int lnum)
{
struct rb_node **p = &done_tree->rb_node, *parent = NULL;
struct done_ref *dr;
while (*p) {
parent = *p;
dr = rb_entry(parent, struct done_ref, rb);
if (lnum < dr->lnum)
p = &(*p)->rb_left;
else if (lnum > dr->lnum)
p = &(*p)->rb_right;
else
return 1;
}
dr = kzalloc(sizeof(struct done_ref), GFP_NOFS);
if (!dr)
return -ENOMEM;
dr->lnum = lnum;
rb_link_node(&dr->rb, parent, p);
rb_insert_color(&dr->rb, done_tree);
return 0;
}
/**
* destroy_done_tree - destroy the done tree.
* @done_tree: done tree to destroy
*/
static void destroy_done_tree(struct rb_root *done_tree)
{
struct rb_node *this = done_tree->rb_node;
struct done_ref *dr;
while (this) {
if (this->rb_left) {
this = this->rb_left;
continue;
} else if (this->rb_right) {
this = this->rb_right;
continue;
}
dr = rb_entry(this, struct done_ref, rb);
this = rb_parent(this);
if (this) {
if (this->rb_left == &dr->rb)
this->rb_left = NULL;
else
this->rb_right = NULL;
}
kfree(dr);
}
}
/**
* add_node - add a node to the consolidated log.
* @c: UBIFS file-system description object
* @buf: buffer to which to add
* @lnum: LEB number to which to write is passed and returned here
* @offs: offset to where to write is passed and returned here
* @node: node to add
*
* This function returns %0 on success and a negative error code on failure.
*/
static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs,
void *node)
{
struct ubifs_ch *ch = node;
int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs;
if (len > remains) {
int sz = ALIGN(*offs, c->min_io_size), err;
ubifs_pad(c, buf + *offs, sz - *offs);
err = ubifs_leb_change(c, *lnum, buf, sz, UBI_SHORTTERM);
if (err)
return err;
*lnum = next_log_lnum(c, *lnum);
*offs = 0;
}
memcpy(buf + *offs, node, len);
*offs += ALIGN(len, 8);
return 0;
}
/**
* ubifs_consolidate_log - consolidate the log.
* @c: UBIFS file-system description object
*
* Repeated failed commits could cause the log to be full, but at least 1 LEB is
* needed for commit. This function rewrites the reference nodes in the log
* omitting duplicates, and failed CS nodes, and leaving no gaps.
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_consolidate_log(struct ubifs_info *c)
{
struct ubifs_scan_leb *sleb;
struct ubifs_scan_node *snod;
struct rb_root done_tree = RB_ROOT;
int lnum, err, first = 1, write_lnum, offs = 0;
void *buf;
dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum,
c->lhead_lnum);
buf = vmalloc(c->leb_size);
if (!buf)
return -ENOMEM;
lnum = c->ltail_lnum;
write_lnum = lnum;
while (1) {
sleb = ubifs_scan(c, lnum, 0, c->sbuf);
if (IS_ERR(sleb)) {
err = PTR_ERR(sleb);
goto out_free;
}
list_for_each_entry(snod, &sleb->nodes, list) {
switch (snod->type) {
case UBIFS_REF_NODE: {
struct ubifs_ref_node *ref = snod->node;
int ref_lnum = le32_to_cpu(ref->lnum);
err = done_already(&done_tree, ref_lnum);
if (err < 0)
goto out_scan;
if (err != 1) {
err = add_node(c, buf, &write_lnum,
&offs, snod->node);
if (err)
goto out_scan;
}
break;
}
case UBIFS_CS_NODE:
if (!first)
break;
err = add_node(c, buf, &write_lnum, &offs,
snod->node);
if (err)
goto out_scan;
first = 0;
break;
}
}
ubifs_scan_destroy(sleb);
if (lnum == c->lhead_lnum)
break;
lnum = next_log_lnum(c, lnum);
}
if (offs) {
int sz = ALIGN(offs, c->min_io_size);
ubifs_pad(c, buf + offs, sz - offs);
err = ubifs_leb_change(c, write_lnum, buf, sz, UBI_SHORTTERM);
if (err)
goto out_free;
offs = ALIGN(offs, c->min_io_size);
}
destroy_done_tree(&done_tree);
vfree(buf);
if (write_lnum == c->lhead_lnum) {
ubifs_err("log is too full");
return -EINVAL;
}
/* Unmap remaining LEBs */
lnum = write_lnum;
do {
lnum = next_log_lnum(c, lnum);
err = ubifs_leb_unmap(c, lnum);
if (err)
return err;
} while (lnum != c->lhead_lnum);
c->lhead_lnum = write_lnum;
c->lhead_offs = offs;
dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs);
return 0;
out_scan:
ubifs_scan_destroy(sleb);
out_free:
destroy_done_tree(&done_tree);
vfree(buf);
return err;
}
#ifdef CONFIG_UBIFS_FS_DEBUG
/**
* dbg_check_bud_bytes - make sure bud bytes calculation are all right.
* @c: UBIFS file-system description object
*
* This function makes sure the amount of flash space used by closed buds
* ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in
* case of failure.
*/
static int dbg_check_bud_bytes(struct ubifs_info *c)
{
int i, err = 0;
struct ubifs_bud *bud;
long long bud_bytes = 0;
if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
return 0;
spin_lock(&c->buds_lock);
for (i = 0; i < c->jhead_cnt; i++)
list_for_each_entry(bud, &c->jheads[i].buds_list, list)
bud_bytes += c->leb_size - bud->start;
if (c->bud_bytes != bud_bytes) {
ubifs_err("bad bud_bytes %lld, calculated %lld",
c->bud_bytes, bud_bytes);
err = -EINVAL;
}
spin_unlock(&c->buds_lock);
return err;
}
#endif /* CONFIG_UBIFS_FS_DEBUG */

1357
fs/ubifs/lprops.c Normal file
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2243
fs/ubifs/lpt.c Normal file
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1648
fs/ubifs/lpt_commit.c Normal file
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387
fs/ubifs/master.c Normal file
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@ -0,0 +1,387 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/* This file implements reading and writing the master node */
#include "ubifs.h"
/**
* scan_for_master - search the valid master node.
* @c: UBIFS file-system description object
*
* This function scans the master node LEBs and search for the latest master
* node. Returns zero in case of success and a negative error code in case of
* failure.
*/
static int scan_for_master(struct ubifs_info *c)
{
struct ubifs_scan_leb *sleb;
struct ubifs_scan_node *snod;
int lnum, offs = 0, nodes_cnt;
lnum = UBIFS_MST_LNUM;
sleb = ubifs_scan(c, lnum, 0, c->sbuf);
if (IS_ERR(sleb))
return PTR_ERR(sleb);
nodes_cnt = sleb->nodes_cnt;
if (nodes_cnt > 0) {
snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
list);
if (snod->type != UBIFS_MST_NODE)
goto out;
memcpy(c->mst_node, snod->node, snod->len);
offs = snod->offs;
}
ubifs_scan_destroy(sleb);
lnum += 1;
sleb = ubifs_scan(c, lnum, 0, c->sbuf);
if (IS_ERR(sleb))
return PTR_ERR(sleb);
if (sleb->nodes_cnt != nodes_cnt)
goto out;
if (!sleb->nodes_cnt)
goto out;
snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
if (snod->type != UBIFS_MST_NODE)
goto out;
if (snod->offs != offs)
goto out;
if (memcmp((void *)c->mst_node + UBIFS_CH_SZ,
(void *)snod->node + UBIFS_CH_SZ,
UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
goto out;
c->mst_offs = offs;
ubifs_scan_destroy(sleb);
return 0;
out:
ubifs_scan_destroy(sleb);
return -EINVAL;
}
/**
* validate_master - validate master node.
* @c: UBIFS file-system description object
*
* This function validates data which was read from master node. Returns zero
* if the data is all right and %-EINVAL if not.
*/
static int validate_master(const struct ubifs_info *c)
{
long long main_sz;
int err;
if (c->max_sqnum >= SQNUM_WATERMARK) {
err = 1;
goto out;
}
if (c->cmt_no >= c->max_sqnum) {
err = 2;
goto out;
}
if (c->highest_inum >= INUM_WATERMARK) {
err = 3;
goto out;
}
if (c->lhead_lnum < UBIFS_LOG_LNUM ||
c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs ||
c->lhead_offs < 0 || c->lhead_offs >= c->leb_size ||
c->lhead_offs & (c->min_io_size - 1)) {
err = 4;
goto out;
}
if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first ||
c->zroot.offs >= c->leb_size || c->zroot.offs & 7) {
err = 5;
goto out;
}
if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len ||
c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) {
err = 6;
goto out;
}
if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) {
err = 7;
goto out;
}
if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first ||
c->ihead_offs % c->min_io_size || c->ihead_offs < 0 ||
c->ihead_offs > c->leb_size || c->ihead_offs & 7) {
err = 8;
goto out;
}
main_sz = (long long)c->main_lebs * c->leb_size;
if (c->old_idx_sz & 7 || c->old_idx_sz >= main_sz) {
err = 9;
goto out;
}
if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last ||
c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) {
err = 10;
goto out;
}
if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last ||
c->nhead_offs < 0 || c->nhead_offs % c->min_io_size ||
c->nhead_offs > c->leb_size) {
err = 11;
goto out;
}
if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last ||
c->ltab_offs < 0 ||
c->ltab_offs + c->ltab_sz > c->leb_size) {
err = 12;
goto out;
}
if (c->big_lpt && (c->lsave_lnum < c->lpt_first ||
c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 ||
c->lsave_offs + c->lsave_sz > c->leb_size)) {
err = 13;
goto out;
}
if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) {
err = 14;
goto out;
}
if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) {
err = 15;
goto out;
}
if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) {
err = 16;
goto out;
}
if (c->lst.total_free < 0 || c->lst.total_free > main_sz ||
c->lst.total_free & 7) {
err = 17;
goto out;
}
if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) {
err = 18;
goto out;
}
if (c->lst.total_used < 0 || (c->lst.total_used & 7)) {
err = 19;
goto out;
}
if (c->lst.total_free + c->lst.total_dirty +
c->lst.total_used > main_sz) {
err = 20;
goto out;
}
if (c->lst.total_dead + c->lst.total_dark +
c->lst.total_used + c->old_idx_sz > main_sz) {
err = 21;
goto out;
}
if (c->lst.total_dead < 0 ||
c->lst.total_dead > c->lst.total_free + c->lst.total_dirty ||
c->lst.total_dead & 7) {
err = 22;
goto out;
}
if (c->lst.total_dark < 0 ||
c->lst.total_dark > c->lst.total_free + c->lst.total_dirty ||
c->lst.total_dark & 7) {
err = 23;
goto out;
}
return 0;
out:
ubifs_err("bad master node at offset %d error %d", c->mst_offs, err);
dbg_dump_node(c, c->mst_node);
return -EINVAL;
}
/**
* ubifs_read_master - read master node.
* @c: UBIFS file-system description object
*
* This function finds and reads the master node during file-system mount. If
* the flash is empty, it creates default master node as well. Returns zero in
* case of success and a negative error code in case of failure.
*/
int ubifs_read_master(struct ubifs_info *c)
{
int err, old_leb_cnt;
c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL);
if (!c->mst_node)
return -ENOMEM;
err = scan_for_master(c);
if (err) {
err = ubifs_recover_master_node(c);
if (err)
/*
* Note, we do not free 'c->mst_node' here because the
* unmount routine will take care of this.
*/
return err;
}
/* Make sure that the recovery flag is clear */
c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY);
c->max_sqnum = le64_to_cpu(c->mst_node->ch.sqnum);
c->highest_inum = le64_to_cpu(c->mst_node->highest_inum);
c->cmt_no = le64_to_cpu(c->mst_node->cmt_no);
c->zroot.lnum = le32_to_cpu(c->mst_node->root_lnum);
c->zroot.offs = le32_to_cpu(c->mst_node->root_offs);
c->zroot.len = le32_to_cpu(c->mst_node->root_len);
c->lhead_lnum = le32_to_cpu(c->mst_node->log_lnum);
c->gc_lnum = le32_to_cpu(c->mst_node->gc_lnum);
c->ihead_lnum = le32_to_cpu(c->mst_node->ihead_lnum);
c->ihead_offs = le32_to_cpu(c->mst_node->ihead_offs);
c->old_idx_sz = le64_to_cpu(c->mst_node->index_size);
c->lpt_lnum = le32_to_cpu(c->mst_node->lpt_lnum);
c->lpt_offs = le32_to_cpu(c->mst_node->lpt_offs);
c->nhead_lnum = le32_to_cpu(c->mst_node->nhead_lnum);
c->nhead_offs = le32_to_cpu(c->mst_node->nhead_offs);
c->ltab_lnum = le32_to_cpu(c->mst_node->ltab_lnum);
c->ltab_offs = le32_to_cpu(c->mst_node->ltab_offs);
c->lsave_lnum = le32_to_cpu(c->mst_node->lsave_lnum);
c->lsave_offs = le32_to_cpu(c->mst_node->lsave_offs);
c->lscan_lnum = le32_to_cpu(c->mst_node->lscan_lnum);
c->lst.empty_lebs = le32_to_cpu(c->mst_node->empty_lebs);
c->lst.idx_lebs = le32_to_cpu(c->mst_node->idx_lebs);
old_leb_cnt = le32_to_cpu(c->mst_node->leb_cnt);
c->lst.total_free = le64_to_cpu(c->mst_node->total_free);
c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty);
c->lst.total_used = le64_to_cpu(c->mst_node->total_used);
c->lst.total_dead = le64_to_cpu(c->mst_node->total_dead);
c->lst.total_dark = le64_to_cpu(c->mst_node->total_dark);
c->calc_idx_sz = c->old_idx_sz;
if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
c->no_orphs = 1;
if (old_leb_cnt != c->leb_cnt) {
/* The file system has been resized */
int growth = c->leb_cnt - old_leb_cnt;
if (c->leb_cnt < old_leb_cnt ||
c->leb_cnt < UBIFS_MIN_LEB_CNT) {
ubifs_err("bad leb_cnt on master node");
dbg_dump_node(c, c->mst_node);
return -EINVAL;
}
dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs",
old_leb_cnt, c->leb_cnt);
c->lst.empty_lebs += growth;
c->lst.total_free += growth * (long long)c->leb_size;
c->lst.total_dark += growth * (long long)c->dark_wm;
/*
* Reflect changes back onto the master node. N.B. the master
* node gets written immediately whenever mounting (or
* remounting) in read-write mode, so we do not need to write it
* here.
*/
c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt);
c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs);
c->mst_node->total_free = cpu_to_le64(c->lst.total_free);
c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark);
}
err = validate_master(c);
if (err)
return err;
err = dbg_old_index_check_init(c, &c->zroot);
return err;
}
/**
* ubifs_write_master - write master node.
* @c: UBIFS file-system description object
*
* This function writes the master node. The caller has to take the
* @c->mst_mutex lock before calling this function. Returns zero in case of
* success and a negative error code in case of failure. The master node is
* written twice to enable recovery.
*/
int ubifs_write_master(struct ubifs_info *c)
{
int err, lnum, offs, len;
if (c->ro_media)
return -EINVAL;
lnum = UBIFS_MST_LNUM;
offs = c->mst_offs + c->mst_node_alsz;
len = UBIFS_MST_NODE_SZ;
if (offs + UBIFS_MST_NODE_SZ > c->leb_size) {
err = ubifs_leb_unmap(c, lnum);
if (err)
return err;
offs = 0;
}
c->mst_offs = offs;
c->mst_node->highest_inum = cpu_to_le64(c->highest_inum);
err = ubifs_write_node(c, c->mst_node, len, lnum, offs, UBI_SHORTTERM);
if (err)
return err;
lnum += 1;
if (offs == 0) {
err = ubifs_leb_unmap(c, lnum);
if (err)
return err;
}
err = ubifs_write_node(c, c->mst_node, len, lnum, offs, UBI_SHORTTERM);
return err;
}

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/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/*
* This file contains miscellaneous helper functions.
*/
#ifndef __UBIFS_MISC_H__
#define __UBIFS_MISC_H__
/**
* ubifs_zn_dirty - check if znode is dirty.
* @znode: znode to check
*
* This helper function returns %1 if @znode is dirty and %0 otherwise.
*/
static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
{
return !!test_bit(DIRTY_ZNODE, &znode->flags);
}
/**
* ubifs_wake_up_bgt - wake up background thread.
* @c: UBIFS file-system description object
*/
static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
{
if (c->bgt && !c->need_bgt) {
c->need_bgt = 1;
wake_up_process(c->bgt);
}
}
/**
* ubifs_tnc_find_child - find next child in znode.
* @znode: znode to search at
* @start: the zbranch index to start at
*
* This helper function looks for znode child starting at index @start. Returns
* the child or %NULL if no children were found.
*/
static inline struct ubifs_znode *
ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
{
while (start < znode->child_cnt) {
if (znode->zbranch[start].znode)
return znode->zbranch[start].znode;
start += 1;
}
return NULL;
}
/**
* ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
* @inode: the VFS 'struct inode' pointer
*/
static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
{
return container_of(inode, struct ubifs_inode, vfs_inode);
}
/**
* ubifs_ro_mode - switch UBIFS to read read-only mode.
* @c: UBIFS file-system description object
* @err: error code which is the reason of switching to R/O mode
*/
static inline void ubifs_ro_mode(struct ubifs_info *c, int err)
{
if (!c->ro_media) {
c->ro_media = 1;
ubifs_warn("switched to read-only mode, error %d", err);
dbg_dump_stack();
}
}
/**
* ubifs_compr_present - check if compressor was compiled in.
* @compr_type: compressor type to check
*
* This function returns %1 of compressor of type @compr_type is present, and
* %0 if not.
*/
static inline int ubifs_compr_present(int compr_type)
{
ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
return !!ubifs_compressors[compr_type]->capi_name;
}
/**
* ubifs_compr_name - get compressor name string by its type.
* @compr_type: compressor type
*
* This function returns compressor type string.
*/
static inline const char *ubifs_compr_name(int compr_type)
{
ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
return ubifs_compressors[compr_type]->name;
}
/**
* ubifs_wbuf_sync - synchronize write-buffer.
* @wbuf: write-buffer to synchronize
*
* This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume
* that the write-buffer is already locked.
*/
static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
{
int err;
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
err = ubifs_wbuf_sync_nolock(wbuf);
mutex_unlock(&wbuf->io_mutex);
return err;
}
/**
* ubifs_leb_unmap - unmap an LEB.
* @c: UBIFS file-system description object
* @lnum: LEB number to unmap
*
* This function returns %0 on success and a negative error code on failure.
*/
static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
{
int err;
if (c->ro_media)
return -EROFS;
err = ubi_leb_unmap(c->ubi, lnum);
if (err) {
ubifs_err("unmap LEB %d failed, error %d", lnum, err);
return err;
}
return 0;
}
/**
* ubifs_leb_write - write to a LEB.
* @c: UBIFS file-system description object
* @lnum: LEB number to write
* @buf: buffer to write from
* @offs: offset within LEB to write to
* @len: length to write
* @dtype: data type
*
* This function returns %0 on success and a negative error code on failure.
*/
static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
const void *buf, int offs, int len, int dtype)
{
int err;
if (c->ro_media)
return -EROFS;
err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
if (err) {
ubifs_err("writing %d bytes at %d:%d, error %d",
len, lnum, offs, err);
return err;
}
return 0;
}
/**
* ubifs_leb_change - atomic LEB change.
* @c: UBIFS file-system description object
* @lnum: LEB number to write
* @buf: buffer to write from
* @len: length to write
* @dtype: data type
*
* This function returns %0 on success and a negative error code on failure.
*/
static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
const void *buf, int len, int dtype)
{
int err;
if (c->ro_media)
return -EROFS;
err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
if (err) {
ubifs_err("changing %d bytes in LEB %d, error %d",
len, lnum, err);
return err;
}
return 0;
}
/**
* ubifs_encode_dev - encode device node IDs.
* @dev: UBIFS device node information
* @rdev: device IDs to encode
*
* This is a helper function which encodes major/minor numbers of a device node
* into UBIFS device node description. We use standard Linux "new" and "huge"
* encodings.
*/
static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
{
if (new_valid_dev(rdev)) {
dev->new = cpu_to_le32(new_encode_dev(rdev));
return sizeof(dev->new);
} else {
dev->huge = cpu_to_le64(huge_encode_dev(rdev));
return sizeof(dev->huge);
}
}
/**
* ubifs_add_dirt - add dirty space to LEB properties.
* @c: the UBIFS file-system description object
* @lnum: LEB to add dirty space for
* @dirty: dirty space to add
*
* This is a helper function which increased amount of dirty LEB space. Returns
* zero in case of success and a negative error code in case of failure.
*/
static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
{
return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
}
/**
* ubifs_return_leb - return LEB to lprops.
* @c: the UBIFS file-system description object
* @lnum: LEB to return
*
* This helper function cleans the "taken" flag of a logical eraseblock in the
* lprops. Returns zero in case of success and a negative error code in case of
* failure.
*/
static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
{
return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
LPROPS_TAKEN, 0);
}
/**
* ubifs_idx_node_sz - return index node size.
* @c: the UBIFS file-system description object
* @child_cnt: number of children of this index node
*/
static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
{
return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt;
}
/**
* ubifs_idx_branch - return pointer to an index branch.
* @c: the UBIFS file-system description object
* @idx: index node
* @bnum: branch number
*/
static inline
struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
const struct ubifs_idx_node *idx,
int bnum)
{
return (struct ubifs_branch *)((void *)idx->branches +
(UBIFS_BRANCH_SZ + c->key_len) * bnum);
}
/**
* ubifs_idx_key - return pointer to an index key.
* @c: the UBIFS file-system description object
* @idx: index node
*/
static inline void *ubifs_idx_key(const struct ubifs_info *c,
const struct ubifs_idx_node *idx)
{
return (void *)((struct ubifs_branch *)idx->branches)->key;
}
/**
* ubifs_reported_space - calculate reported free space.
* @c: the UBIFS file-system description object
* @free: amount of free space
*
* This function calculates amount of free space which will be reported to
* user-space. User-space application tend to expect that if the file-system
* (e.g., via the 'statfs()' call) reports that it has N bytes available, they
* are able to write a file of size N. UBIFS attaches node headers to each data
* node and it has to write indexind nodes as well. This introduces additional
* overhead, and UBIFS it has to report sligtly less free space to meet the
* above expectetion.
*
* This function assumes free space is made up of uncompressed data nodes and
* full index nodes (one per data node, doubled because we always allow enough
* space to write the index twice).
*
* Note, the calculation is pessimistic, which means that most of the time
* UBIFS reports less space than it actually has.
*/
static inline long long ubifs_reported_space(const struct ubifs_info *c,
uint64_t free)
{
int divisor, factor;
divisor = UBIFS_MAX_DATA_NODE_SZ + (c->max_idx_node_sz << 1);
factor = UBIFS_MAX_DATA_NODE_SZ - UBIFS_DATA_NODE_SZ;
do_div(free, divisor);
return free * factor;
}
/**
* ubifs_current_time - round current time to time granularity.
* @inode: inode
*/
static inline struct timespec ubifs_current_time(struct inode *inode)
{
return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
}
#endif /* __UBIFS_MISC_H__ */

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/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Author: Adrian Hunter
*/
#include "ubifs.h"
/*
* An orphan is an inode number whose inode node has been committed to the index
* with a link count of zero. That happens when an open file is deleted
* (unlinked) and then a commit is run. In the normal course of events the inode
* would be deleted when the file is closed. However in the case of an unclean
* unmount, orphans need to be accounted for. After an unclean unmount, the
* orphans' inodes must be deleted which means either scanning the entire index
* looking for them, or keeping a list on flash somewhere. This unit implements
* the latter approach.
*
* The orphan area is a fixed number of LEBs situated between the LPT area and
* the main area. The number of orphan area LEBs is specified when the file
* system is created. The minimum number is 1. The size of the orphan area
* should be so that it can hold the maximum number of orphans that are expected
* to ever exist at one time.
*
* The number of orphans that can fit in a LEB is:
*
* (c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64)
*
* For example: a 15872 byte LEB can fit 1980 orphans so 1 LEB may be enough.
*
* Orphans are accumulated in a rb-tree. When an inode's link count drops to
* zero, the inode number is added to the rb-tree. It is removed from the tree
* when the inode is deleted. Any new orphans that are in the orphan tree when
* the commit is run, are written to the orphan area in 1 or more orph nodes.
* If the orphan area is full, it is consolidated to make space. There is
* always enough space because validation prevents the user from creating more
* than the maximum number of orphans allowed.
*/
#ifdef CONFIG_UBIFS_FS_DEBUG
static int dbg_check_orphans(struct ubifs_info *c);
#else
#define dbg_check_orphans(c) 0
#endif
/**
* ubifs_add_orphan - add an orphan.
* @c: UBIFS file-system description object
* @inum: orphan inode number
*
* Add an orphan. This function is called when an inodes link count drops to
* zero.
*/
int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
{
struct ubifs_orphan *orphan, *o;
struct rb_node **p, *parent = NULL;
orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_NOFS);
if (!orphan)
return -ENOMEM;
orphan->inum = inum;
orphan->new = 1;
spin_lock(&c->orphan_lock);
if (c->tot_orphans >= c->max_orphans) {
spin_unlock(&c->orphan_lock);
kfree(orphan);
return -ENFILE;
}
p = &c->orph_tree.rb_node;
while (*p) {
parent = *p;
o = rb_entry(parent, struct ubifs_orphan, rb);
if (inum < o->inum)
p = &(*p)->rb_left;
else if (inum > o->inum)
p = &(*p)->rb_right;
else {
dbg_err("orphaned twice");
spin_unlock(&c->orphan_lock);
kfree(orphan);
return 0;
}
}
c->tot_orphans += 1;
c->new_orphans += 1;
rb_link_node(&orphan->rb, parent, p);
rb_insert_color(&orphan->rb, &c->orph_tree);
list_add_tail(&orphan->list, &c->orph_list);
list_add_tail(&orphan->new_list, &c->orph_new);
spin_unlock(&c->orphan_lock);
dbg_gen("ino %lu", inum);
return 0;
}
/**
* ubifs_delete_orphan - delete an orphan.
* @c: UBIFS file-system description object
* @inum: orphan inode number
*
* Delete an orphan. This function is called when an inode is deleted.
*/
void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum)
{
struct ubifs_orphan *o;
struct rb_node *p;
spin_lock(&c->orphan_lock);
p = c->orph_tree.rb_node;
while (p) {
o = rb_entry(p, struct ubifs_orphan, rb);
if (inum < o->inum)
p = p->rb_left;
else if (inum > o->inum)
p = p->rb_right;
else {
if (o->dnext) {
spin_unlock(&c->orphan_lock);
dbg_gen("deleted twice ino %lu", inum);
return;
}
if (o->cnext) {
o->dnext = c->orph_dnext;
c->orph_dnext = o;
spin_unlock(&c->orphan_lock);
dbg_gen("delete later ino %lu", inum);
return;
}
rb_erase(p, &c->orph_tree);
list_del(&o->list);
c->tot_orphans -= 1;
if (o->new) {
list_del(&o->new_list);
c->new_orphans -= 1;
}
spin_unlock(&c->orphan_lock);
kfree(o);
dbg_gen("inum %lu", inum);
return;
}
}
spin_unlock(&c->orphan_lock);
dbg_err("missing orphan ino %lu", inum);
dbg_dump_stack();
}
/**
* ubifs_orphan_start_commit - start commit of orphans.
* @c: UBIFS file-system description object
*
* Start commit of orphans.
*/
int ubifs_orphan_start_commit(struct ubifs_info *c)
{
struct ubifs_orphan *orphan, **last;
spin_lock(&c->orphan_lock);
last = &c->orph_cnext;
list_for_each_entry(orphan, &c->orph_new, new_list) {
ubifs_assert(orphan->new);
orphan->new = 0;
*last = orphan;
last = &orphan->cnext;
}
*last = orphan->cnext;
c->cmt_orphans = c->new_orphans;
c->new_orphans = 0;
dbg_cmt("%d orphans to commit", c->cmt_orphans);
INIT_LIST_HEAD(&c->orph_new);
if (c->tot_orphans == 0)
c->no_orphs = 1;
else
c->no_orphs = 0;
spin_unlock(&c->orphan_lock);
return 0;
}
/**
* avail_orphs - calculate available space.
* @c: UBIFS file-system description object
*
* This function returns the number of orphans that can be written in the
* available space.
*/
static int avail_orphs(struct ubifs_info *c)
{
int avail_lebs, avail, gap;
avail_lebs = c->orph_lebs - (c->ohead_lnum - c->orph_first) - 1;
avail = avail_lebs *
((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
gap = c->leb_size - c->ohead_offs;
if (gap >= UBIFS_ORPH_NODE_SZ + sizeof(__le64))
avail += (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
return avail;
}
/**
* tot_avail_orphs - calculate total space.
* @c: UBIFS file-system description object
*
* This function returns the number of orphans that can be written in half
* the total space. That leaves half the space for adding new orphans.
*/
static int tot_avail_orphs(struct ubifs_info *c)
{
int avail_lebs, avail;
avail_lebs = c->orph_lebs;
avail = avail_lebs *
((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
return avail / 2;
}
/**
* do_write_orph_node - write a node
* @c: UBIFS file-system description object
* @len: length of node
* @atomic: write atomically
*
* This function writes a node to the orphan head from the orphan buffer. If
* %atomic is not zero, then the write is done atomically. On success, %0 is
* returned, otherwise a negative error code is returned.
*/
static int do_write_orph_node(struct ubifs_info *c, int len, int atomic)
{
int err = 0;
if (atomic) {
ubifs_assert(c->ohead_offs == 0);
ubifs_prepare_node(c, c->orph_buf, len, 1);
len = ALIGN(len, c->min_io_size);
err = ubifs_leb_change(c, c->ohead_lnum, c->orph_buf, len,
UBI_SHORTTERM);
} else {
if (c->ohead_offs == 0) {
/* Ensure LEB has been unmapped */
err = ubifs_leb_unmap(c, c->ohead_lnum);
if (err)
return err;
}
err = ubifs_write_node(c, c->orph_buf, len, c->ohead_lnum,
c->ohead_offs, UBI_SHORTTERM);
}
return err;
}
/**
* write_orph_node - write an orph node
* @c: UBIFS file-system description object
* @atomic: write atomically
*
* This function builds an orph node from the cnext list and writes it to the
* orphan head. On success, %0 is returned, otherwise a negative error code
* is returned.
*/
static int write_orph_node(struct ubifs_info *c, int atomic)
{
struct ubifs_orphan *orphan, *cnext;
struct ubifs_orph_node *orph;
int gap, err, len, cnt, i;
ubifs_assert(c->cmt_orphans > 0);
gap = c->leb_size - c->ohead_offs;
if (gap < UBIFS_ORPH_NODE_SZ + sizeof(__le64)) {
c->ohead_lnum += 1;
c->ohead_offs = 0;
gap = c->leb_size;
if (c->ohead_lnum > c->orph_last) {
/*
* We limit the number of orphans so that this should
* never happen.
*/
ubifs_err("out of space in orphan area");
return -EINVAL;
}
}
cnt = (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
if (cnt > c->cmt_orphans)
cnt = c->cmt_orphans;
len = UBIFS_ORPH_NODE_SZ + cnt * sizeof(__le64);
ubifs_assert(c->orph_buf);
orph = c->orph_buf;
orph->ch.node_type = UBIFS_ORPH_NODE;
spin_lock(&c->orphan_lock);
cnext = c->orph_cnext;
for (i = 0; i < cnt; i++) {
orphan = cnext;
orph->inos[i] = cpu_to_le64(orphan->inum);
cnext = orphan->cnext;
orphan->cnext = NULL;
}
c->orph_cnext = cnext;
c->cmt_orphans -= cnt;
spin_unlock(&c->orphan_lock);
if (c->cmt_orphans)
orph->cmt_no = cpu_to_le64(c->cmt_no + 1);
else
/* Mark the last node of the commit */
orph->cmt_no = cpu_to_le64((c->cmt_no + 1) | (1ULL << 63));
ubifs_assert(c->ohead_offs + len <= c->leb_size);
ubifs_assert(c->ohead_lnum >= c->orph_first);
ubifs_assert(c->ohead_lnum <= c->orph_last);
err = do_write_orph_node(c, len, atomic);
c->ohead_offs += ALIGN(len, c->min_io_size);
c->ohead_offs = ALIGN(c->ohead_offs, 8);
return err;
}
/**
* write_orph_nodes - write orph nodes until there are no more to commit
* @c: UBIFS file-system description object
* @atomic: write atomically
*
* This function writes orph nodes for all the orphans to commit. On success,
* %0 is returned, otherwise a negative error code is returned.
*/
static int write_orph_nodes(struct ubifs_info *c, int atomic)
{
int err;
while (c->cmt_orphans > 0) {
err = write_orph_node(c, atomic);
if (err)
return err;
}
if (atomic) {
int lnum;
/* Unmap any unused LEBs after consolidation */
lnum = c->ohead_lnum + 1;
for (lnum = c->ohead_lnum + 1; lnum <= c->orph_last; lnum++) {
err = ubifs_leb_unmap(c, lnum);
if (err)
return err;
}
}
return 0;
}
/**
* consolidate - consolidate the orphan area.
* @c: UBIFS file-system description object
*
* This function enables consolidation by putting all the orphans into the list
* to commit. The list is in the order that the orphans were added, and the
* LEBs are written atomically in order, so at no time can orphans be lost by
* an unclean unmount.
*
* This function returns %0 on success and a negative error code on failure.
*/
static int consolidate(struct ubifs_info *c)
{
int tot_avail = tot_avail_orphs(c), err = 0;
spin_lock(&c->orphan_lock);
dbg_cmt("there is space for %d orphans and there are %d",
tot_avail, c->tot_orphans);
if (c->tot_orphans - c->new_orphans <= tot_avail) {
struct ubifs_orphan *orphan, **last;
int cnt = 0;
/* Change the cnext list to include all non-new orphans */
last = &c->orph_cnext;
list_for_each_entry(orphan, &c->orph_list, list) {
if (orphan->new)
continue;
*last = orphan;
last = &orphan->cnext;
cnt += 1;
}
*last = orphan->cnext;
ubifs_assert(cnt == c->tot_orphans - c->new_orphans);
c->cmt_orphans = cnt;
c->ohead_lnum = c->orph_first;
c->ohead_offs = 0;
} else {
/*
* We limit the number of orphans so that this should
* never happen.
*/
ubifs_err("out of space in orphan area");
err = -EINVAL;
}
spin_unlock(&c->orphan_lock);
return err;
}
/**
* commit_orphans - commit orphans.
* @c: UBIFS file-system description object
*
* This function commits orphans to flash. On success, %0 is returned,
* otherwise a negative error code is returned.
*/
static int commit_orphans(struct ubifs_info *c)
{
int avail, atomic = 0, err;
ubifs_assert(c->cmt_orphans > 0);
avail = avail_orphs(c);
if (avail < c->cmt_orphans) {
/* Not enough space to write new orphans, so consolidate */
err = consolidate(c);
if (err)
return err;
atomic = 1;
}
err = write_orph_nodes(c, atomic);
return err;
}
/**
* erase_deleted - erase the orphans marked for deletion.
* @c: UBIFS file-system description object
*
* During commit, the orphans being committed cannot be deleted, so they are
* marked for deletion and deleted by this function. Also, the recovery
* adds killed orphans to the deletion list, and therefore they are deleted
* here too.
*/
static void erase_deleted(struct ubifs_info *c)
{
struct ubifs_orphan *orphan, *dnext;
spin_lock(&c->orphan_lock);
dnext = c->orph_dnext;
while (dnext) {
orphan = dnext;
dnext = orphan->dnext;
ubifs_assert(!orphan->new);
rb_erase(&orphan->rb, &c->orph_tree);
list_del(&orphan->list);
c->tot_orphans -= 1;
dbg_gen("deleting orphan ino %lu", orphan->inum);
kfree(orphan);
}
c->orph_dnext = NULL;
spin_unlock(&c->orphan_lock);
}
/**
* ubifs_orphan_end_commit - end commit of orphans.
* @c: UBIFS file-system description object
*
* End commit of orphans.
*/
int ubifs_orphan_end_commit(struct ubifs_info *c)
{
int err;
if (c->cmt_orphans != 0) {
err = commit_orphans(c);
if (err)
return err;
}
erase_deleted(c);
err = dbg_check_orphans(c);
return err;
}
/**
* clear_orphans - erase all LEBs used for orphans.
* @c: UBIFS file-system description object
*
* If recovery is not required, then the orphans from the previous session
* are not needed. This function locates the LEBs used to record
* orphans, and un-maps them.
*/
static int clear_orphans(struct ubifs_info *c)
{
int lnum, err;
for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
err = ubifs_leb_unmap(c, lnum);
if (err)
return err;
}
c->ohead_lnum = c->orph_first;
c->ohead_offs = 0;
return 0;
}
/**
* insert_dead_orphan - insert an orphan.
* @c: UBIFS file-system description object
* @inum: orphan inode number
*
* This function is a helper to the 'do_kill_orphans()' function. The orphan
* must be kept until the next commit, so it is added to the rb-tree and the
* deletion list.
*/
static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
{
struct ubifs_orphan *orphan, *o;
struct rb_node **p, *parent = NULL;
orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL);
if (!orphan)
return -ENOMEM;
orphan->inum = inum;
p = &c->orph_tree.rb_node;
while (*p) {
parent = *p;
o = rb_entry(parent, struct ubifs_orphan, rb);
if (inum < o->inum)
p = &(*p)->rb_left;
else if (inum > o->inum)
p = &(*p)->rb_right;
else {
/* Already added - no problem */
kfree(orphan);
return 0;
}
}
c->tot_orphans += 1;
rb_link_node(&orphan->rb, parent, p);
rb_insert_color(&orphan->rb, &c->orph_tree);
list_add_tail(&orphan->list, &c->orph_list);
orphan->dnext = c->orph_dnext;
c->orph_dnext = orphan;
dbg_mnt("ino %lu, new %d, tot %d",
inum, c->new_orphans, c->tot_orphans);
return 0;
}
/**
* do_kill_orphans - remove orphan inodes from the index.
* @c: UBIFS file-system description object
* @sleb: scanned LEB
* @last_cmt_no: cmt_no of last orph node read is passed and returned here
* @outofdate: whether the LEB is out of date is returned here
* @last_flagged: whether the end orph node is encountered
*
* This function is a helper to the 'kill_orphans()' function. It goes through
* every orphan node in a LEB and for every inode number recorded, removes
* all keys for that inode from the TNC.
*/
static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
unsigned long long *last_cmt_no, int *outofdate,
int *last_flagged)
{
struct ubifs_scan_node *snod;
struct ubifs_orph_node *orph;
unsigned long long cmt_no;
ino_t inum;
int i, n, err, first = 1;
list_for_each_entry(snod, &sleb->nodes, list) {
if (snod->type != UBIFS_ORPH_NODE) {
ubifs_err("invalid node type %d in orphan area at "
"%d:%d", snod->type, sleb->lnum, snod->offs);
dbg_dump_node(c, snod->node);
return -EINVAL;
}
orph = snod->node;
/* Check commit number */
cmt_no = le64_to_cpu(orph->cmt_no) & LLONG_MAX;
/*
* The commit number on the master node may be less, because
* of a failed commit. If there are several failed commits in a
* row, the commit number written on orph nodes will continue to
* increase (because the commit number is adjusted here) even
* though the commit number on the master node stays the same
* because the master node has not been re-written.
*/
if (cmt_no > c->cmt_no)
c->cmt_no = cmt_no;
if (cmt_no < *last_cmt_no && *last_flagged) {
/*
* The last orph node had a higher commit number and was
* flagged as the last written for that commit number.
* That makes this orph node, out of date.
*/
if (!first) {
ubifs_err("out of order commit number %llu in "
"orphan node at %d:%d",
cmt_no, sleb->lnum, snod->offs);
dbg_dump_node(c, snod->node);
return -EINVAL;
}
dbg_rcvry("out of date LEB %d", sleb->lnum);
*outofdate = 1;
return 0;
}
if (first)
first = 0;
n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
for (i = 0; i < n; i++) {
inum = le64_to_cpu(orph->inos[i]);
dbg_rcvry("deleting orphaned inode %lu", inum);
err = ubifs_tnc_remove_ino(c, inum);
if (err)
return err;
err = insert_dead_orphan(c, inum);
if (err)
return err;
}
*last_cmt_no = cmt_no;
if (le64_to_cpu(orph->cmt_no) & (1ULL << 63)) {
dbg_rcvry("last orph node for commit %llu at %d:%d",
cmt_no, sleb->lnum, snod->offs);
*last_flagged = 1;
} else
*last_flagged = 0;
}
return 0;
}
/**
* kill_orphans - remove all orphan inodes from the index.
* @c: UBIFS file-system description object
*
* If recovery is required, then orphan inodes recorded during the previous
* session (which ended with an unclean unmount) must be deleted from the index.
* This is done by updating the TNC, but since the index is not updated until
* the next commit, the LEBs where the orphan information is recorded are not
* erased until the next commit.
*/
static int kill_orphans(struct ubifs_info *c)
{
unsigned long long last_cmt_no = 0;
int lnum, err = 0, outofdate = 0, last_flagged = 0;
c->ohead_lnum = c->orph_first;
c->ohead_offs = 0;
/* Check no-orphans flag and skip this if no orphans */
if (c->no_orphs) {
dbg_rcvry("no orphans");
return 0;
}
/*
* Orph nodes always start at c->orph_first and are written to each
* successive LEB in turn. Generally unused LEBs will have been unmapped
* but may contain out of date orph nodes if the unmap didn't go
* through. In addition, the last orph node written for each commit is
* marked (top bit of orph->cmt_no is set to 1). It is possible that
* there are orph nodes from the next commit (i.e. the commit did not
* complete successfully). In that case, no orphans will have been lost
* due to the way that orphans are written, and any orphans added will
* be valid orphans anyway and so can be deleted.
*/
for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
struct ubifs_scan_leb *sleb;
dbg_rcvry("LEB %d", lnum);
sleb = ubifs_scan(c, lnum, 0, c->sbuf);
if (IS_ERR(sleb)) {
sleb = ubifs_recover_leb(c, lnum, 0, c->sbuf, 0);
if (IS_ERR(sleb)) {
err = PTR_ERR(sleb);
break;
}
}
err = do_kill_orphans(c, sleb, &last_cmt_no, &outofdate,
&last_flagged);
if (err || outofdate) {
ubifs_scan_destroy(sleb);
break;
}
if (sleb->endpt) {
c->ohead_lnum = lnum;
c->ohead_offs = sleb->endpt;
}
ubifs_scan_destroy(sleb);
}
return err;
}
/**
* ubifs_mount_orphans - delete orphan inodes and erase LEBs that recorded them.
* @c: UBIFS file-system description object
* @unclean: indicates recovery from unclean unmount
* @read_only: indicates read only mount
*
* This function is called when mounting to erase orphans from the previous
* session. If UBIFS was not unmounted cleanly, then the inodes recorded as
* orphans are deleted.
*/
int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only)
{
int err = 0;
c->max_orphans = tot_avail_orphs(c);
if (!read_only) {
c->orph_buf = vmalloc(c->leb_size);
if (!c->orph_buf)
return -ENOMEM;
}
if (unclean)
err = kill_orphans(c);
else if (!read_only)
err = clear_orphans(c);
return err;
}
#ifdef CONFIG_UBIFS_FS_DEBUG
struct check_orphan {
struct rb_node rb;
ino_t inum;
};
struct check_info {
unsigned long last_ino;
unsigned long tot_inos;
unsigned long missing;
unsigned long long leaf_cnt;
struct ubifs_ino_node *node;
struct rb_root root;
};
static int dbg_find_orphan(struct ubifs_info *c, ino_t inum)
{
struct ubifs_orphan *o;
struct rb_node *p;
spin_lock(&c->orphan_lock);
p = c->orph_tree.rb_node;
while (p) {
o = rb_entry(p, struct ubifs_orphan, rb);
if (inum < o->inum)
p = p->rb_left;
else if (inum > o->inum)
p = p->rb_right;
else {
spin_unlock(&c->orphan_lock);
return 1;
}
}
spin_unlock(&c->orphan_lock);
return 0;
}
static int dbg_ins_check_orphan(struct rb_root *root, ino_t inum)
{
struct check_orphan *orphan, *o;
struct rb_node **p, *parent = NULL;
orphan = kzalloc(sizeof(struct check_orphan), GFP_NOFS);
if (!orphan)
return -ENOMEM;
orphan->inum = inum;
p = &root->rb_node;
while (*p) {
parent = *p;
o = rb_entry(parent, struct check_orphan, rb);
if (inum < o->inum)
p = &(*p)->rb_left;
else if (inum > o->inum)
p = &(*p)->rb_right;
else {
kfree(orphan);
return 0;
}
}
rb_link_node(&orphan->rb, parent, p);
rb_insert_color(&orphan->rb, root);
return 0;
}
static int dbg_find_check_orphan(struct rb_root *root, ino_t inum)
{
struct check_orphan *o;
struct rb_node *p;
p = root->rb_node;
while (p) {
o = rb_entry(p, struct check_orphan, rb);
if (inum < o->inum)
p = p->rb_left;
else if (inum > o->inum)
p = p->rb_right;
else
return 1;
}
return 0;
}
static void dbg_free_check_tree(struct rb_root *root)
{
struct rb_node *this = root->rb_node;
struct check_orphan *o;
while (this) {
if (this->rb_left) {
this = this->rb_left;
continue;
} else if (this->rb_right) {
this = this->rb_right;
continue;
}
o = rb_entry(this, struct check_orphan, rb);
this = rb_parent(this);
if (this) {
if (this->rb_left == &o->rb)
this->rb_left = NULL;
else
this->rb_right = NULL;
}
kfree(o);
}
}
static int dbg_orphan_check(struct ubifs_info *c, struct ubifs_zbranch *zbr,
void *priv)
{
struct check_info *ci = priv;
ino_t inum;
int err;
inum = key_inum(c, &zbr->key);
if (inum != ci->last_ino) {
/* Lowest node type is the inode node, so it comes first */
if (key_type(c, &zbr->key) != UBIFS_INO_KEY)
ubifs_err("found orphan node ino %lu, type %d", inum,
key_type(c, &zbr->key));
ci->last_ino = inum;
ci->tot_inos += 1;
err = ubifs_tnc_read_node(c, zbr, ci->node);
if (err) {
ubifs_err("node read failed, error %d", err);
return err;
}
if (ci->node->nlink == 0)
/* Must be recorded as an orphan */
if (!dbg_find_check_orphan(&ci->root, inum) &&
!dbg_find_orphan(c, inum)) {
ubifs_err("missing orphan, ino %lu", inum);
ci->missing += 1;
}
}
ci->leaf_cnt += 1;
return 0;
}
static int dbg_read_orphans(struct check_info *ci, struct ubifs_scan_leb *sleb)
{
struct ubifs_scan_node *snod;
struct ubifs_orph_node *orph;
ino_t inum;
int i, n, err;
list_for_each_entry(snod, &sleb->nodes, list) {
cond_resched();
if (snod->type != UBIFS_ORPH_NODE)
continue;
orph = snod->node;
n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
for (i = 0; i < n; i++) {
inum = le64_to_cpu(orph->inos[i]);
err = dbg_ins_check_orphan(&ci->root, inum);
if (err)
return err;
}
}
return 0;
}
static int dbg_scan_orphans(struct ubifs_info *c, struct check_info *ci)
{
int lnum, err = 0;
/* Check no-orphans flag and skip this if no orphans */
if (c->no_orphs)
return 0;
for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
struct ubifs_scan_leb *sleb;
sleb = ubifs_scan(c, lnum, 0, c->dbg_buf);
if (IS_ERR(sleb)) {
err = PTR_ERR(sleb);
break;
}
err = dbg_read_orphans(ci, sleb);
ubifs_scan_destroy(sleb);
if (err)
break;
}
return err;
}
static int dbg_check_orphans(struct ubifs_info *c)
{
struct check_info ci;
int err;
if (!(ubifs_chk_flags & UBIFS_CHK_ORPH))
return 0;
ci.last_ino = 0;
ci.tot_inos = 0;
ci.missing = 0;
ci.leaf_cnt = 0;
ci.root = RB_ROOT;
ci.node = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
if (!ci.node) {
ubifs_err("out of memory");
return -ENOMEM;
}
err = dbg_scan_orphans(c, &ci);
if (err)
goto out;
err = dbg_walk_index(c, &dbg_orphan_check, NULL, &ci);
if (err) {
ubifs_err("cannot scan TNC, error %d", err);
goto out;
}
if (ci.missing) {
ubifs_err("%lu missing orphan(s)", ci.missing);
err = -EINVAL;
goto out;
}
dbg_cmt("last inode number is %lu", ci.last_ino);
dbg_cmt("total number of inodes is %lu", ci.tot_inos);
dbg_cmt("total number of leaf nodes is %llu", ci.leaf_cnt);
out:
dbg_free_check_tree(&ci.root);
kfree(ci.node);
return err;
}
#endif /* CONFIG_UBIFS_FS_DEBUG */

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@ -0,0 +1,629 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/*
* This file implements UBIFS superblock. The superblock is stored at the first
* LEB of the volume and is never changed by UBIFS. Only user-space tools may
* change it. The superblock node mostly contains geometry information.
*/
#include "ubifs.h"
#include <linux/random.h>
/*
* Default journal size in logical eraseblocks as a percent of total
* flash size.
*/
#define DEFAULT_JNL_PERCENT 5
/* Default maximum journal size in bytes */
#define DEFAULT_MAX_JNL (32*1024*1024)
/* Default indexing tree fanout */
#define DEFAULT_FANOUT 8
/* Default number of data journal heads */
#define DEFAULT_JHEADS_CNT 1
/* Default positions of different LEBs in the main area */
#define DEFAULT_IDX_LEB 0
#define DEFAULT_DATA_LEB 1
#define DEFAULT_GC_LEB 2
/* Default number of LEB numbers in LPT's save table */
#define DEFAULT_LSAVE_CNT 256
/* Default reserved pool size as a percent of maximum free space */
#define DEFAULT_RP_PERCENT 5
/* The default maximum size of reserved pool in bytes */
#define DEFAULT_MAX_RP_SIZE (5*1024*1024)
/* Default time granularity in nanoseconds */
#define DEFAULT_TIME_GRAN 1000000000
/**
* create_default_filesystem - format empty UBI volume.
* @c: UBIFS file-system description object
*
* This function creates default empty file-system. Returns zero in case of
* success and a negative error code in case of failure.
*/
static int create_default_filesystem(struct ubifs_info *c)
{
struct ubifs_sb_node *sup;
struct ubifs_mst_node *mst;
struct ubifs_idx_node *idx;
struct ubifs_branch *br;
struct ubifs_ino_node *ino;
struct ubifs_cs_node *cs;
union ubifs_key key;
int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first;
int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;
int min_leb_cnt = UBIFS_MIN_LEB_CNT;
uint64_t tmp64, main_bytes;
/* Some functions called from here depend on the @c->key_len filed */
c->key_len = UBIFS_SK_LEN;
/*
* First of all, we have to calculate default file-system geometry -
* log size, journal size, etc.
*/
if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
/* We can first multiply then divide and have no overflow */
jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
else
jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
jnl_lebs = UBIFS_MIN_JNL_LEBS;
if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
/*
* The log should be large enough to fit reference nodes for all bud
* LEBs. Because buds do not have to start from the beginning of LEBs
* (half of the LEB may contain committed data), the log should
* generally be larger, make it twice as large.
*/
tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
log_lebs = tmp / c->leb_size;
/* Plus one LEB reserved for commit */
log_lebs += 1;
if (c->leb_cnt - min_leb_cnt > 8) {
/* And some extra space to allow writes while committing */
log_lebs += 1;
min_leb_cnt += 1;
}
max_buds = jnl_lebs - log_lebs;
if (max_buds < UBIFS_MIN_BUD_LEBS)
max_buds = UBIFS_MIN_BUD_LEBS;
/*
* Orphan nodes are stored in a separate area. One node can store a lot
* of orphan inode numbers, but when new orphan comes we just add a new
* orphan node. At some point the nodes are consolidated into one
* orphan node.
*/
orph_lebs = UBIFS_MIN_ORPH_LEBS;
#ifdef CONFIG_UBIFS_FS_DEBUG
if (c->leb_cnt - min_leb_cnt > 1)
/*
* For debugging purposes it is better to have at least 2
* orphan LEBs, because the orphan subsystem would need to do
* consolidations and would be stressed more.
*/
orph_lebs += 1;
#endif
main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
main_lebs -= orph_lebs;
lpt_first = UBIFS_LOG_LNUM + log_lebs;
c->lsave_cnt = DEFAULT_LSAVE_CNT;
c->max_leb_cnt = c->leb_cnt;
err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
&big_lpt);
if (err)
return err;
dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
lpt_first + lpt_lebs - 1);
main_first = c->leb_cnt - main_lebs;
/* Create default superblock */
tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
sup = kzalloc(tmp, GFP_KERNEL);
if (!sup)
return -ENOMEM;
tmp64 = (uint64_t)max_buds * c->leb_size;
if (big_lpt)
sup_flags |= UBIFS_FLG_BIGLPT;
sup->ch.node_type = UBIFS_SB_NODE;
sup->key_hash = UBIFS_KEY_HASH_R5;
sup->flags = cpu_to_le32(sup_flags);
sup->min_io_size = cpu_to_le32(c->min_io_size);
sup->leb_size = cpu_to_le32(c->leb_size);
sup->leb_cnt = cpu_to_le32(c->leb_cnt);
sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
sup->max_bud_bytes = cpu_to_le64(tmp64);
sup->log_lebs = cpu_to_le32(log_lebs);
sup->lpt_lebs = cpu_to_le32(lpt_lebs);
sup->orph_lebs = cpu_to_le32(orph_lebs);
sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION);
sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
generate_random_uuid(sup->uuid);
main_bytes = (uint64_t)main_lebs * c->leb_size;
tmp64 = main_bytes * DEFAULT_RP_PERCENT;
do_div(tmp64, 100);
if (tmp64 > DEFAULT_MAX_RP_SIZE)
tmp64 = DEFAULT_MAX_RP_SIZE;
sup->rp_size = cpu_to_le64(tmp64);
err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM);
kfree(sup);
if (err)
return err;
dbg_gen("default superblock created at LEB 0:0");
/* Create default master node */
mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
if (!mst)
return -ENOMEM;
mst->ch.node_type = UBIFS_MST_NODE;
mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
mst->cmt_no = 0;
mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
mst->root_offs = 0;
tmp = ubifs_idx_node_sz(c, 1);
mst->root_len = cpu_to_le32(tmp);
mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
mst->lpt_offs = cpu_to_le32(c->lpt_offs);
mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
mst->nhead_offs = cpu_to_le32(c->nhead_offs);
mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
mst->ltab_offs = cpu_to_le32(c->ltab_offs);
mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
mst->lsave_offs = cpu_to_le32(c->lsave_offs);
mst->lscan_lnum = cpu_to_le32(main_first);
mst->empty_lebs = cpu_to_le32(main_lebs - 2);
mst->idx_lebs = cpu_to_le32(1);
mst->leb_cnt = cpu_to_le32(c->leb_cnt);
/* Calculate lprops statistics */
tmp64 = main_bytes;
tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
mst->total_free = cpu_to_le64(tmp64);
tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
UBIFS_INO_NODE_SZ;
tmp64 += ino_waste;
tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
mst->total_dirty = cpu_to_le64(tmp64);
/* The indexing LEB does not contribute to dark space */
tmp64 = (c->main_lebs - 1) * c->dark_wm;
mst->total_dark = cpu_to_le64(tmp64);
mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
UBI_UNKNOWN);
if (err) {
kfree(mst);
return err;
}
err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0,
UBI_UNKNOWN);
kfree(mst);
if (err)
return err;
dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
/* Create the root indexing node */
tmp = ubifs_idx_node_sz(c, 1);
idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
if (!idx)
return -ENOMEM;
c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
c->key_hash = key_r5_hash;
idx->ch.node_type = UBIFS_IDX_NODE;
idx->child_cnt = cpu_to_le16(1);
ino_key_init(c, &key, UBIFS_ROOT_INO);
br = ubifs_idx_branch(c, idx, 0);
key_write_idx(c, &key, &br->key);
br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0,
UBI_UNKNOWN);
kfree(idx);
if (err)
return err;
dbg_gen("default root indexing node created LEB %d:0",
main_first + DEFAULT_IDX_LEB);
/* Create default root inode */
tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
ino = kzalloc(tmp, GFP_KERNEL);
if (!ino)
return -ENOMEM;
ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
ino->ch.node_type = UBIFS_INO_NODE;
ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
ino->nlink = cpu_to_le32(2);
tmp = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
ino->atime_sec = tmp;
ino->ctime_sec = tmp;
ino->mtime_sec = tmp;
ino->atime_nsec = 0;
ino->ctime_nsec = 0;
ino->mtime_nsec = 0;
ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
/* Set compression enabled by default */
ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
main_first + DEFAULT_DATA_LEB, 0,
UBI_UNKNOWN);
kfree(ino);
if (err)
return err;
dbg_gen("root inode created at LEB %d:0",
main_first + DEFAULT_DATA_LEB);
/*
* The first node in the log has to be the commit start node. This is
* always the case during normal file-system operation. Write a fake
* commit start node to the log.
*/
tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
cs = kzalloc(tmp, GFP_KERNEL);
if (!cs)
return -ENOMEM;
cs->ch.node_type = UBIFS_CS_NODE;
err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM,
0, UBI_UNKNOWN);
kfree(cs);
ubifs_msg("default file-system created");
return 0;
}
/**
* validate_sb - validate superblock node.
* @c: UBIFS file-system description object
* @sup: superblock node
*
* This function validates superblock node @sup. Since most of data was read
* from the superblock and stored in @c, the function validates fields in @c
* instead. Returns zero in case of success and %-EINVAL in case of validation
* failure.
*/
static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
{
long long max_bytes;
int err = 1, min_leb_cnt;
if (!c->key_hash) {
err = 2;
goto failed;
}
if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
err = 3;
goto failed;
}
if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
ubifs_err("min. I/O unit mismatch: %d in superblock, %d real",
le32_to_cpu(sup->min_io_size), c->min_io_size);
goto failed;
}
if (le32_to_cpu(sup->leb_size) != c->leb_size) {
ubifs_err("LEB size mismatch: %d in superblock, %d real",
le32_to_cpu(sup->leb_size), c->leb_size);
goto failed;
}
if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
err = 4;
goto failed;
}
/*
* Calculate minimum allowed amount of main area LEBs. This is very
* similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
* have just read from the superblock.
*/
min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
ubifs_err("bad LEB count: %d in superblock, %d on UBI volume, "
"%d minimum required", c->leb_cnt, c->vi.size,
min_leb_cnt);
goto failed;
}
if (c->max_leb_cnt < c->leb_cnt) {
ubifs_err("max. LEB count %d less than LEB count %d",
c->max_leb_cnt, c->leb_cnt);
goto failed;
}
if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
err = 7;
goto failed;
}
if (c->max_bud_bytes < (long long)c->leb_size * UBIFS_MIN_BUD_LEBS ||
c->max_bud_bytes > (long long)c->leb_size * c->main_lebs) {
err = 8;
goto failed;
}
if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
err = 9;
goto failed;
}
if (c->fanout < UBIFS_MIN_FANOUT ||
ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
err = 10;
goto failed;
}
if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
err = 11;
goto failed;
}
if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
c->orph_lebs + c->main_lebs != c->leb_cnt) {
err = 12;
goto failed;
}
if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
err = 13;
goto failed;
}
max_bytes = c->main_lebs * (long long)c->leb_size;
if (c->rp_size < 0 || max_bytes < c->rp_size) {
err = 14;
goto failed;
}
if (le32_to_cpu(sup->time_gran) > 1000000000 ||
le32_to_cpu(sup->time_gran) < 1) {
err = 15;
goto failed;
}
return 0;
failed:
ubifs_err("bad superblock, error %d", err);
dbg_dump_node(c, sup);
return -EINVAL;
}
/**
* ubifs_read_sb_node - read superblock node.
* @c: UBIFS file-system description object
*
* This function returns a pointer to the superblock node or a negative error
* code.
*/
struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
{
struct ubifs_sb_node *sup;
int err;
sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
if (!sup)
return ERR_PTR(-ENOMEM);
err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
UBIFS_SB_LNUM, 0);
if (err) {
kfree(sup);
return ERR_PTR(err);
}
return sup;
}
/**
* ubifs_write_sb_node - write superblock node.
* @c: UBIFS file-system description object
* @sup: superblock node read with 'ubifs_read_sb_node()'
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
{
int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len, UBI_LONGTERM);
}
/**
* ubifs_read_superblock - read superblock.
* @c: UBIFS file-system description object
*
* This function finds, reads and checks the superblock. If an empty UBI volume
* is being mounted, this function creates default superblock. Returns zero in
* case of success, and a negative error code in case of failure.
*/
int ubifs_read_superblock(struct ubifs_info *c)
{
int err, sup_flags;
struct ubifs_sb_node *sup;
if (c->empty) {
err = create_default_filesystem(c);
if (err)
return err;
}
sup = ubifs_read_sb_node(c);
if (IS_ERR(sup))
return PTR_ERR(sup);
/*
* The software supports all previous versions but not future versions,
* due to the unavailability of time-travelling equipment.
*/
c->fmt_version = le32_to_cpu(sup->fmt_version);
if (c->fmt_version > UBIFS_FORMAT_VERSION) {
ubifs_err("on-flash format version is %d, but software only "
"supports up to version %d", c->fmt_version,
UBIFS_FORMAT_VERSION);
err = -EINVAL;
goto out;
}
if (c->fmt_version < 3) {
ubifs_err("on-flash format version %d is not supported",
c->fmt_version);
err = -EINVAL;
goto out;
}
switch (sup->key_hash) {
case UBIFS_KEY_HASH_R5:
c->key_hash = key_r5_hash;
c->key_hash_type = UBIFS_KEY_HASH_R5;
break;
case UBIFS_KEY_HASH_TEST:
c->key_hash = key_test_hash;
c->key_hash_type = UBIFS_KEY_HASH_TEST;
break;
};
c->key_fmt = sup->key_fmt;
switch (c->key_fmt) {
case UBIFS_SIMPLE_KEY_FMT:
c->key_len = UBIFS_SK_LEN;
break;
default:
ubifs_err("unsupported key format");
err = -EINVAL;
goto out;
}
c->leb_cnt = le32_to_cpu(sup->leb_cnt);
c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
c->log_lebs = le32_to_cpu(sup->log_lebs);
c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
c->orph_lebs = le32_to_cpu(sup->orph_lebs);
c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
c->fanout = le32_to_cpu(sup->fanout);
c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
c->default_compr = le16_to_cpu(sup->default_compr);
c->rp_size = le64_to_cpu(sup->rp_size);
c->rp_uid = le32_to_cpu(sup->rp_uid);
c->rp_gid = le32_to_cpu(sup->rp_gid);
sup_flags = le32_to_cpu(sup->flags);
c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
memcpy(&c->uuid, &sup->uuid, 16);
c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
/* Automatically increase file system size to the maximum size */
c->old_leb_cnt = c->leb_cnt;
if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
if (c->vfs_sb->s_flags & MS_RDONLY)
dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
c->old_leb_cnt, c->leb_cnt);
else {
dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
c->old_leb_cnt, c->leb_cnt);
sup->leb_cnt = cpu_to_le32(c->leb_cnt);
err = ubifs_write_sb_node(c, sup);
if (err)
goto out;
c->old_leb_cnt = c->leb_cnt;
}
}
c->log_bytes = (long long)c->log_lebs * c->leb_size;
c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
c->orph_first = c->lpt_last + 1;
c->orph_last = c->orph_first + c->orph_lebs - 1;
c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
c->main_first = c->leb_cnt - c->main_lebs;
c->report_rp_size = ubifs_reported_space(c, c->rp_size);
err = validate_sb(c, sup);
out:
kfree(sup);
return err;
}

362
fs/ubifs/scan.c Normal file
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@ -0,0 +1,362 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Adrian Hunter
* Artem Bityutskiy (Битюцкий Артём)
*/
/*
* This file implements the scan which is a general-purpose function for
* determining what nodes are in an eraseblock. The scan is used to replay the
* journal, to do garbage collection. for the TNC in-the-gaps method, and by
* debugging functions.
*/
#include "ubifs.h"
/**
* scan_padding_bytes - scan for padding bytes.
* @buf: buffer to scan
* @len: length of buffer
*
* This function returns the number of padding bytes on success and
* %SCANNED_GARBAGE on failure.
*/
static int scan_padding_bytes(void *buf, int len)
{
int pad_len = 0, max_pad_len = min_t(int, UBIFS_PAD_NODE_SZ, len);
uint8_t *p = buf;
dbg_scan("not a node");
while (pad_len < max_pad_len && *p++ == UBIFS_PADDING_BYTE)
pad_len += 1;
if (!pad_len || (pad_len & 7))
return SCANNED_GARBAGE;
dbg_scan("%d padding bytes", pad_len);
return pad_len;
}
/**
* ubifs_scan_a_node - scan for a node or padding.
* @c: UBIFS file-system description object
* @buf: buffer to scan
* @len: length of buffer
* @lnum: logical eraseblock number
* @offs: offset within the logical eraseblock
* @quiet: print no messages
*
* This function returns a scanning code to indicate what was scanned.
*/
int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum,
int offs, int quiet)
{
struct ubifs_ch *ch = buf;
uint32_t magic;
magic = le32_to_cpu(ch->magic);
if (magic == 0xFFFFFFFF) {
dbg_scan("hit empty space");
return SCANNED_EMPTY_SPACE;
}
if (magic != UBIFS_NODE_MAGIC)
return scan_padding_bytes(buf, len);
if (len < UBIFS_CH_SZ)
return SCANNED_GARBAGE;
dbg_scan("scanning %s", dbg_ntype(ch->node_type));
if (ubifs_check_node(c, buf, lnum, offs, quiet))
return SCANNED_A_CORRUPT_NODE;
if (ch->node_type == UBIFS_PAD_NODE) {
struct ubifs_pad_node *pad = buf;
int pad_len = le32_to_cpu(pad->pad_len);
int node_len = le32_to_cpu(ch->len);
/* Validate the padding node */
if (pad_len < 0 ||
offs + node_len + pad_len > c->leb_size) {
if (!quiet) {
ubifs_err("bad pad node at LEB %d:%d",
lnum, offs);
dbg_dump_node(c, pad);
}
return SCANNED_A_BAD_PAD_NODE;
}
/* Make the node pads to 8-byte boundary */
if ((node_len + pad_len) & 7) {
if (!quiet) {
dbg_err("bad padding length %d - %d",
offs, offs + node_len + pad_len);
}
return SCANNED_A_BAD_PAD_NODE;
}
dbg_scan("%d bytes padded, offset now %d",
pad_len, ALIGN(offs + node_len + pad_len, 8));
return node_len + pad_len;
}
return SCANNED_A_NODE;
}
/**
* ubifs_start_scan - create LEB scanning information at start of scan.
* @c: UBIFS file-system description object
* @lnum: logical eraseblock number
* @offs: offset to start at (usually zero)
* @sbuf: scan buffer (must be c->leb_size)
*
* This function returns %0 on success and a negative error code on failure.
*/
struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum,
int offs, void *sbuf)
{
struct ubifs_scan_leb *sleb;
int err;
dbg_scan("scan LEB %d:%d", lnum, offs);
sleb = kzalloc(sizeof(struct ubifs_scan_leb), GFP_NOFS);
if (!sleb)
return ERR_PTR(-ENOMEM);
sleb->lnum = lnum;
INIT_LIST_HEAD(&sleb->nodes);
sleb->buf = sbuf;
err = ubi_read(c->ubi, lnum, sbuf + offs, offs, c->leb_size - offs);
if (err && err != -EBADMSG) {
ubifs_err("cannot read %d bytes from LEB %d:%d,"
" error %d", c->leb_size - offs, lnum, offs, err);
kfree(sleb);
return ERR_PTR(err);
}
if (err == -EBADMSG)
sleb->ecc = 1;
return sleb;
}
/**
* ubifs_end_scan - update LEB scanning information at end of scan.
* @c: UBIFS file-system description object
* @sleb: scanning information
* @lnum: logical eraseblock number
* @offs: offset to start at (usually zero)
*
* This function returns %0 on success and a negative error code on failure.
*/
void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
int lnum, int offs)
{
lnum = lnum;
dbg_scan("stop scanning LEB %d at offset %d", lnum, offs);
ubifs_assert(offs % c->min_io_size == 0);
sleb->endpt = ALIGN(offs, c->min_io_size);
}
/**
* ubifs_add_snod - add a scanned node to LEB scanning information.
* @c: UBIFS file-system description object
* @sleb: scanning information
* @buf: buffer containing node
* @offs: offset of node on flash
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
void *buf, int offs)
{
struct ubifs_ch *ch = buf;
struct ubifs_ino_node *ino = buf;
struct ubifs_scan_node *snod;
snod = kzalloc(sizeof(struct ubifs_scan_node), GFP_NOFS);
if (!snod)
return -ENOMEM;
snod->sqnum = le64_to_cpu(ch->sqnum);
snod->type = ch->node_type;
snod->offs = offs;
snod->len = le32_to_cpu(ch->len);
snod->node = buf;
switch (ch->node_type) {
case UBIFS_INO_NODE:
case UBIFS_DENT_NODE:
case UBIFS_XENT_NODE:
case UBIFS_DATA_NODE:
case UBIFS_TRUN_NODE:
/*
* The key is in the same place in all keyed
* nodes.
*/
key_read(c, &ino->key, &snod->key);
break;
}
list_add_tail(&snod->list, &sleb->nodes);
sleb->nodes_cnt += 1;
return 0;
}
/**
* ubifs_scanned_corruption - print information after UBIFS scanned corruption.
* @c: UBIFS file-system description object
* @lnum: LEB number of corruption
* @offs: offset of corruption
* @buf: buffer containing corruption
*/
void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
void *buf)
{
int len;
ubifs_err("corrupted data at LEB %d:%d", lnum, offs);
if (dbg_failure_mode)
return;
len = c->leb_size - offs;
if (len > 4096)
len = 4096;
dbg_err("first %d bytes from LEB %d:%d", len, lnum, offs);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
}
/**
* ubifs_scan - scan a logical eraseblock.
* @c: UBIFS file-system description object
* @lnum: logical eraseblock number
* @offs: offset to start at (usually zero)
* @sbuf: scan buffer (must be c->leb_size)
*
* This function scans LEB number @lnum and returns complete information about
* its contents. Returns an error code in case of failure.
*/
struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum,
int offs, void *sbuf)
{
void *buf = sbuf + offs;
int err, len = c->leb_size - offs;
struct ubifs_scan_leb *sleb;
sleb = ubifs_start_scan(c, lnum, offs, sbuf);
if (IS_ERR(sleb))
return sleb;
while (len >= 8) {
struct ubifs_ch *ch = buf;
int node_len, ret;
dbg_scan("look at LEB %d:%d (%d bytes left)",
lnum, offs, len);
cond_resched();
ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 0);
if (ret > 0) {
/* Padding bytes or a valid padding node */
offs += ret;
buf += ret;
len -= ret;
continue;
}
if (ret == SCANNED_EMPTY_SPACE)
/* Empty space is checked later */
break;
switch (ret) {
case SCANNED_GARBAGE:
dbg_err("garbage");
goto corrupted;
case SCANNED_A_NODE:
break;
case SCANNED_A_CORRUPT_NODE:
case SCANNED_A_BAD_PAD_NODE:
dbg_err("bad node");
goto corrupted;
default:
dbg_err("unknown");
goto corrupted;
}
err = ubifs_add_snod(c, sleb, buf, offs);
if (err)
goto error;
node_len = ALIGN(le32_to_cpu(ch->len), 8);
offs += node_len;
buf += node_len;
len -= node_len;
}
if (offs % c->min_io_size)
goto corrupted;
ubifs_end_scan(c, sleb, lnum, offs);
for (; len > 4; offs += 4, buf = buf + 4, len -= 4)
if (*(uint32_t *)buf != 0xffffffff)
break;
for (; len; offs++, buf++, len--)
if (*(uint8_t *)buf != 0xff) {
ubifs_err("corrupt empty space at LEB %d:%d",
lnum, offs);
goto corrupted;
}
return sleb;
corrupted:
ubifs_scanned_corruption(c, lnum, offs, buf);
err = -EUCLEAN;
error:
ubifs_err("LEB %d scanning failed", lnum);
ubifs_scan_destroy(sleb);
return ERR_PTR(err);
}
/**
* ubifs_scan_destroy - destroy LEB scanning information.
* @sleb: scanning information to free
*/
void ubifs_scan_destroy(struct ubifs_scan_leb *sleb)
{
struct ubifs_scan_node *node;
struct list_head *head;
head = &sleb->nodes;
while (!list_empty(head)) {
node = list_entry(head->next, struct ubifs_scan_node, list);
list_del(&node->list);
kfree(node);
}
kfree(sleb);
}

322
fs/ubifs/shrinker.c Normal file
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@ -0,0 +1,322 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/*
* This file implements UBIFS shrinker which evicts clean znodes from the TNC
* tree when Linux VM needs more RAM.
*
* We do not implement any LRU lists to find oldest znodes to free because it
* would add additional overhead to the file system fast paths. So the shrinker
* just walks the TNC tree when searching for znodes to free.
*
* If the root of a TNC sub-tree is clean and old enough, then the children are
* also clean and old enough. So the shrinker walks the TNC in level order and
* dumps entire sub-trees.
*
* The age of znodes is just the time-stamp when they were last looked at.
* The current shrinker first tries to evict old znodes, then young ones.
*
* Since the shrinker is global, it has to protect against races with FS
* un-mounts, which is done by the 'ubifs_infos_lock' and 'c->umount_mutex'.
*/
#include "ubifs.h"
/* List of all UBIFS file-system instances */
LIST_HEAD(ubifs_infos);
/*
* We number each shrinker run and record the number on the ubifs_info structure
* so that we can easily work out which ubifs_info structures have already been
* done by the current run.
*/
static unsigned int shrinker_run_no;
/* Protects 'ubifs_infos' list */
DEFINE_SPINLOCK(ubifs_infos_lock);
/* Global clean znode counter (for all mounted UBIFS instances) */
atomic_long_t ubifs_clean_zn_cnt;
/**
* shrink_tnc - shrink TNC tree.
* @c: UBIFS file-system description object
* @nr: number of znodes to free
* @age: the age of znodes to free
* @contention: if any contention, this is set to %1
*
* This function traverses TNC tree and frees clean znodes. It does not free
* clean znodes which younger then @age. Returns number of freed znodes.
*/
static int shrink_tnc(struct ubifs_info *c, int nr, int age, int *contention)
{
int total_freed = 0;
struct ubifs_znode *znode, *zprev;
int time = get_seconds();
ubifs_assert(mutex_is_locked(&c->umount_mutex));
ubifs_assert(mutex_is_locked(&c->tnc_mutex));
if (!c->zroot.znode || atomic_long_read(&c->clean_zn_cnt) == 0)
return 0;
/*
* Traverse the TNC tree in levelorder manner, so that it is possible
* to destroy large sub-trees. Indeed, if a znode is old, then all its
* children are older or of the same age.
*
* Note, we are holding 'c->tnc_mutex', so we do not have to lock the
* 'c->space_lock' when _reading_ 'c->clean_zn_cnt', because it is
* changed only when the 'c->tnc_mutex' is held.
*/
zprev = NULL;
znode = ubifs_tnc_levelorder_next(c->zroot.znode, NULL);
while (znode && total_freed < nr &&
atomic_long_read(&c->clean_zn_cnt) > 0) {
int freed;
/*
* If the znode is clean, but it is in the 'c->cnext' list, this
* means that this znode has just been written to flash as a
* part of commit and was marked clean. They will be removed
* from the list at end commit. We cannot change the list,
* because it is not protected by any mutex (design decision to
* make commit really independent and parallel to main I/O). So
* we just skip these znodes.
*
* Note, the 'clean_zn_cnt' counters are not updated until
* after the commit, so the UBIFS shrinker does not report
* the znodes which are in the 'c->cnext' list as freeable.
*
* Also note, if the root of a sub-tree is not in 'c->cnext',
* then the whole sub-tree is not in 'c->cnext' as well, so it
* is safe to dump whole sub-tree.
*/
if (znode->cnext) {
/*
* Very soon these znodes will be removed from the list
* and become freeable.
*/
*contention = 1;
} else if (!ubifs_zn_dirty(znode) &&
abs(time - znode->time) >= age) {
if (znode->parent)
znode->parent->zbranch[znode->iip].znode = NULL;
else
c->zroot.znode = NULL;
freed = ubifs_destroy_tnc_subtree(znode);
atomic_long_sub(freed, &ubifs_clean_zn_cnt);
atomic_long_sub(freed, &c->clean_zn_cnt);
ubifs_assert(atomic_long_read(&c->clean_zn_cnt) >= 0);
total_freed += freed;
znode = zprev;
}
if (unlikely(!c->zroot.znode))
break;
zprev = znode;
znode = ubifs_tnc_levelorder_next(c->zroot.znode, znode);
cond_resched();
}
return total_freed;
}
/**
* shrink_tnc_trees - shrink UBIFS TNC trees.
* @nr: number of znodes to free
* @age: the age of znodes to free
* @contention: if any contention, this is set to %1
*
* This function walks the list of mounted UBIFS file-systems and frees clean
* znodes which are older then @age, until at least @nr znodes are freed.
* Returns the number of freed znodes.
*/
static int shrink_tnc_trees(int nr, int age, int *contention)
{
struct ubifs_info *c;
struct list_head *p;
unsigned int run_no;
int freed = 0;
spin_lock(&ubifs_infos_lock);
do {
run_no = ++shrinker_run_no;
} while (run_no == 0);
/* Iterate over all mounted UBIFS file-systems and try to shrink them */
p = ubifs_infos.next;
while (p != &ubifs_infos) {
c = list_entry(p, struct ubifs_info, infos_list);
/*
* We move the ones we do to the end of the list, so we stop
* when we see one we have already done.
*/
if (c->shrinker_run_no == run_no)
break;
if (!mutex_trylock(&c->umount_mutex)) {
/* Some un-mount is in progress, try next FS */
*contention = 1;
p = p->next;
continue;
}
/*
* We're holding 'c->umount_mutex', so the file-system won't go
* away.
*/
if (!mutex_trylock(&c->tnc_mutex)) {
mutex_unlock(&c->umount_mutex);
*contention = 1;
p = p->next;
continue;
}
spin_unlock(&ubifs_infos_lock);
/*
* OK, now we have TNC locked, the file-system cannot go away -
* it is safe to reap the cache.
*/
c->shrinker_run_no = run_no;
freed += shrink_tnc(c, nr, age, contention);
mutex_unlock(&c->tnc_mutex);
spin_lock(&ubifs_infos_lock);
/* Get the next list element before we move this one */
p = p->next;
/*
* Move this one to the end of the list to provide some
* fairness.
*/
list_del(&c->infos_list);
list_add_tail(&c->infos_list, &ubifs_infos);
mutex_unlock(&c->umount_mutex);
if (freed >= nr)
break;
}
spin_unlock(&ubifs_infos_lock);
return freed;
}
/**
* kick_a_thread - kick a background thread to start commit.
*
* This function kicks a background thread to start background commit. Returns
* %-1 if a thread was kicked or there is another reason to assume the memory
* will soon be freed or become freeable. If there are no dirty znodes, returns
* %0.
*/
static int kick_a_thread(void)
{
int i;
struct ubifs_info *c;
/*
* Iterate over all mounted UBIFS file-systems and find out if there is
* already an ongoing commit operation there. If no, then iterate for
* the second time and initiate background commit.
*/
spin_lock(&ubifs_infos_lock);
for (i = 0; i < 2; i++) {
list_for_each_entry(c, &ubifs_infos, infos_list) {
long dirty_zn_cnt;
if (!mutex_trylock(&c->umount_mutex)) {
/*
* Some un-mount is in progress, it will
* certainly free memory, so just return.
*/
spin_unlock(&ubifs_infos_lock);
return -1;
}
dirty_zn_cnt = atomic_long_read(&c->dirty_zn_cnt);
if (!dirty_zn_cnt || c->cmt_state == COMMIT_BROKEN ||
c->ro_media) {
mutex_unlock(&c->umount_mutex);
continue;
}
if (c->cmt_state != COMMIT_RESTING) {
spin_unlock(&ubifs_infos_lock);
mutex_unlock(&c->umount_mutex);
return -1;
}
if (i == 1) {
list_del(&c->infos_list);
list_add_tail(&c->infos_list, &ubifs_infos);
spin_unlock(&ubifs_infos_lock);
ubifs_request_bg_commit(c);
mutex_unlock(&c->umount_mutex);
return -1;
}
mutex_unlock(&c->umount_mutex);
}
}
spin_unlock(&ubifs_infos_lock);
return 0;
}
int ubifs_shrinker(int nr, gfp_t gfp_mask)
{
int freed, contention = 0;
long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
if (nr == 0)
return clean_zn_cnt;
if (!clean_zn_cnt) {
/*
* No clean znodes, nothing to reap. All we can do in this case
* is to kick background threads to start commit, which will
* probably make clean znodes which, in turn, will be freeable.
* And we return -1 which means will make VM call us again
* later.
*/
dbg_tnc("no clean znodes, kick a thread");
return kick_a_thread();
}
freed = shrink_tnc_trees(nr, OLD_ZNODE_AGE, &contention);
if (freed >= nr)
goto out;
dbg_tnc("not enough old znodes, try to free young ones");
freed += shrink_tnc_trees(nr - freed, YOUNG_ZNODE_AGE, &contention);
if (freed >= nr)
goto out;
dbg_tnc("not enough young znodes, free all");
freed += shrink_tnc_trees(nr - freed, 0, &contention);
if (!freed && contention) {
dbg_tnc("freed nothing, but contention");
return -1;
}
out:
dbg_tnc("%d znodes were freed, requested %d", freed, nr);
return freed;
}

1951
fs/ubifs/super.c Normal file
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File diff suppressed because it is too large Load Diff

2956
fs/ubifs/tnc.c Normal file
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File diff suppressed because it is too large Load Diff

1103
fs/ubifs/tnc_commit.c Normal file
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494
fs/ubifs/tnc_misc.c Normal file
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@ -0,0 +1,494 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Adrian Hunter
* Artem Bityutskiy (Битюцкий Артём)
*/
/*
* This file contains miscelanious TNC-related functions shared betweend
* different files. This file does not form any logically separate TNC
* sub-system. The file was created because there is a lot of TNC code and
* putting it all in one file would make that file too big and unreadable.
*/
#include "ubifs.h"
/**
* ubifs_tnc_levelorder_next - next TNC tree element in levelorder traversal.
* @zr: root of the subtree to traverse
* @znode: previous znode
*
* This function implements levelorder TNC traversal. The LNC is ignored.
* Returns the next element or %NULL if @znode is already the last one.
*/
struct ubifs_znode *ubifs_tnc_levelorder_next(struct ubifs_znode *zr,
struct ubifs_znode *znode)
{
int level, iip, level_search = 0;
struct ubifs_znode *zn;
ubifs_assert(zr);
if (unlikely(!znode))
return zr;
if (unlikely(znode == zr)) {
if (znode->level == 0)
return NULL;
return ubifs_tnc_find_child(zr, 0);
}
level = znode->level;
iip = znode->iip;
while (1) {
ubifs_assert(znode->level <= zr->level);
/*
* First walk up until there is a znode with next branch to
* look at.
*/
while (znode->parent != zr && iip >= znode->parent->child_cnt) {
znode = znode->parent;
iip = znode->iip;
}
if (unlikely(znode->parent == zr &&
iip >= znode->parent->child_cnt)) {
/* This level is done, switch to the lower one */
level -= 1;
if (level_search || level < 0)
/*
* We were already looking for znode at lower
* level ('level_search'). As we are here
* again, it just does not exist. Or all levels
* were finished ('level < 0').
*/
return NULL;
level_search = 1;
iip = -1;
znode = ubifs_tnc_find_child(zr, 0);
ubifs_assert(znode);
}
/* Switch to the next index */
zn = ubifs_tnc_find_child(znode->parent, iip + 1);
if (!zn) {
/* No more children to look at, we have walk up */
iip = znode->parent->child_cnt;
continue;
}
/* Walk back down to the level we came from ('level') */
while (zn->level != level) {
znode = zn;
zn = ubifs_tnc_find_child(zn, 0);
if (!zn) {
/*
* This path is not too deep so it does not
* reach 'level'. Try next path.
*/
iip = znode->iip;
break;
}
}
if (zn) {
ubifs_assert(zn->level >= 0);
return zn;
}
}
}
/**
* ubifs_search_zbranch - search znode branch.
* @c: UBIFS file-system description object
* @znode: znode to search in
* @key: key to search for
* @n: znode branch slot number is returned here
*
* This is a helper function which search branch with key @key in @znode using
* binary search. The result of the search may be:
* o exact match, then %1 is returned, and the slot number of the branch is
* stored in @n;
* o no exact match, then %0 is returned and the slot number of the left
* closest branch is returned in @n; the slot if all keys in this znode are
* greater than @key, then %-1 is returned in @n.
*/
int ubifs_search_zbranch(const struct ubifs_info *c,
const struct ubifs_znode *znode,
const union ubifs_key *key, int *n)
{
int beg = 0, end = znode->child_cnt, uninitialized_var(mid);
int uninitialized_var(cmp);
const struct ubifs_zbranch *zbr = &znode->zbranch[0];
ubifs_assert(end > beg);
while (end > beg) {
mid = (beg + end) >> 1;
cmp = keys_cmp(c, key, &zbr[mid].key);
if (cmp > 0)
beg = mid + 1;
else if (cmp < 0)
end = mid;
else {
*n = mid;
return 1;
}
}
*n = end - 1;
/* The insert point is after *n */
ubifs_assert(*n >= -1 && *n < znode->child_cnt);
if (*n == -1)
ubifs_assert(keys_cmp(c, key, &zbr[0].key) < 0);
else
ubifs_assert(keys_cmp(c, key, &zbr[*n].key) > 0);
if (*n + 1 < znode->child_cnt)
ubifs_assert(keys_cmp(c, key, &zbr[*n + 1].key) < 0);
return 0;
}
/**
* ubifs_tnc_postorder_first - find first znode to do postorder tree traversal.
* @znode: znode to start at (root of the sub-tree to traverse)
*
* Find the lowest leftmost znode in a subtree of the TNC tree. The LNC is
* ignored.
*/
struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode)
{
if (unlikely(!znode))
return NULL;
while (znode->level > 0) {
struct ubifs_znode *child;
child = ubifs_tnc_find_child(znode, 0);
if (!child)
return znode;
znode = child;
}
return znode;
}
/**
* ubifs_tnc_postorder_next - next TNC tree element in postorder traversal.
* @znode: previous znode
*
* This function implements postorder TNC traversal. The LNC is ignored.
* Returns the next element or %NULL if @znode is already the last one.
*/
struct ubifs_znode *ubifs_tnc_postorder_next(struct ubifs_znode *znode)
{
struct ubifs_znode *zn;
ubifs_assert(znode);
if (unlikely(!znode->parent))
return NULL;
/* Switch to the next index in the parent */
zn = ubifs_tnc_find_child(znode->parent, znode->iip + 1);
if (!zn)
/* This is in fact the last child, return parent */
return znode->parent;
/* Go to the first znode in this new subtree */
return ubifs_tnc_postorder_first(zn);
}
/**
* ubifs_destroy_tnc_subtree - destroy all znodes connected to a subtree.
* @znode: znode defining subtree to destroy
*
* This function destroys subtree of the TNC tree. Returns number of clean
* znodes in the subtree.
*/
long ubifs_destroy_tnc_subtree(struct ubifs_znode *znode)
{
struct ubifs_znode *zn = ubifs_tnc_postorder_first(znode);
long clean_freed = 0;
int n;
ubifs_assert(zn);
while (1) {
for (n = 0; n < zn->child_cnt; n++) {
if (!zn->zbranch[n].znode)
continue;
if (zn->level > 0 &&
!ubifs_zn_dirty(zn->zbranch[n].znode))
clean_freed += 1;
cond_resched();
kfree(zn->zbranch[n].znode);
}
if (zn == znode) {
if (!ubifs_zn_dirty(zn))
clean_freed += 1;
kfree(zn);
return clean_freed;
}
zn = ubifs_tnc_postorder_next(zn);
}
}
/**
* read_znode - read an indexing node from flash and fill znode.
* @c: UBIFS file-system description object
* @lnum: LEB of the indexing node to read
* @offs: node offset
* @len: node length
* @znode: znode to read to
*
* This function reads an indexing node from the flash media and fills znode
* with the read data. Returns zero in case of success and a negative error
* code in case of failure. The read indexing node is validated and if anything
* is wrong with it, this function prints complaint messages and returns
* %-EINVAL.
*/
static int read_znode(struct ubifs_info *c, int lnum, int offs, int len,
struct ubifs_znode *znode)
{
int i, err, type, cmp;
struct ubifs_idx_node *idx;
idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
if (!idx)
return -ENOMEM;
err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
if (err < 0) {
kfree(idx);
return err;
}
znode->child_cnt = le16_to_cpu(idx->child_cnt);
znode->level = le16_to_cpu(idx->level);
dbg_tnc("LEB %d:%d, level %d, %d branch",
lnum, offs, znode->level, znode->child_cnt);
if (znode->child_cnt > c->fanout || znode->level > UBIFS_MAX_LEVELS) {
dbg_err("current fanout %d, branch count %d",
c->fanout, znode->child_cnt);
dbg_err("max levels %d, znode level %d",
UBIFS_MAX_LEVELS, znode->level);
err = 1;
goto out_dump;
}
for (i = 0; i < znode->child_cnt; i++) {
const struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
struct ubifs_zbranch *zbr = &znode->zbranch[i];
key_read(c, &br->key, &zbr->key);
zbr->lnum = le32_to_cpu(br->lnum);
zbr->offs = le32_to_cpu(br->offs);
zbr->len = le32_to_cpu(br->len);
zbr->znode = NULL;
/* Validate branch */
if (zbr->lnum < c->main_first ||
zbr->lnum >= c->leb_cnt || zbr->offs < 0 ||
zbr->offs + zbr->len > c->leb_size || zbr->offs & 7) {
dbg_err("bad branch %d", i);
err = 2;
goto out_dump;
}
switch (key_type(c, &zbr->key)) {
case UBIFS_INO_KEY:
case UBIFS_DATA_KEY:
case UBIFS_DENT_KEY:
case UBIFS_XENT_KEY:
break;
default:
dbg_msg("bad key type at slot %d: %s", i,
DBGKEY(&zbr->key));
err = 3;
goto out_dump;
}
if (znode->level)
continue;
type = key_type(c, &zbr->key);
if (c->ranges[type].max_len == 0) {
if (zbr->len != c->ranges[type].len) {
dbg_err("bad target node (type %d) length (%d)",
type, zbr->len);
dbg_err("have to be %d", c->ranges[type].len);
err = 4;
goto out_dump;
}
} else if (zbr->len < c->ranges[type].min_len ||
zbr->len > c->ranges[type].max_len) {
dbg_err("bad target node (type %d) length (%d)",
type, zbr->len);
dbg_err("have to be in range of %d-%d",
c->ranges[type].min_len,
c->ranges[type].max_len);
err = 5;
goto out_dump;
}
}
/*
* Ensure that the next key is greater or equivalent to the
* previous one.
*/
for (i = 0; i < znode->child_cnt - 1; i++) {
const union ubifs_key *key1, *key2;
key1 = &znode->zbranch[i].key;
key2 = &znode->zbranch[i + 1].key;
cmp = keys_cmp(c, key1, key2);
if (cmp > 0) {
dbg_err("bad key order (keys %d and %d)", i, i + 1);
err = 6;
goto out_dump;
} else if (cmp == 0 && !is_hash_key(c, key1)) {
/* These can only be keys with colliding hash */
dbg_err("keys %d and %d are not hashed but equivalent",
i, i + 1);
err = 7;
goto out_dump;
}
}
kfree(idx);
return 0;
out_dump:
ubifs_err("bad indexing node at LEB %d:%d, error %d", lnum, offs, err);
dbg_dump_node(c, idx);
kfree(idx);
return -EINVAL;
}
/**
* ubifs_load_znode - load znode to TNC cache.
* @c: UBIFS file-system description object
* @zbr: znode branch
* @parent: znode's parent
* @iip: index in parent
*
* This function loads znode pointed to by @zbr into the TNC cache and
* returns pointer to it in case of success and a negative error code in case
* of failure.
*/
struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c,
struct ubifs_zbranch *zbr,
struct ubifs_znode *parent, int iip)
{
int err;
struct ubifs_znode *znode;
ubifs_assert(!zbr->znode);
/*
* A slab cache is not presently used for znodes because the znode size
* depends on the fanout which is stored in the superblock.
*/
znode = kzalloc(c->max_znode_sz, GFP_NOFS);
if (!znode)
return ERR_PTR(-ENOMEM);
err = read_znode(c, zbr->lnum, zbr->offs, zbr->len, znode);
if (err)
goto out;
atomic_long_inc(&c->clean_zn_cnt);
/*
* Increment the global clean znode counter as well. It is OK that
* global and per-FS clean znode counters may be inconsistent for some
* short time (because we might be preempted at this point), the global
* one is only used in shrinker.
*/
atomic_long_inc(&ubifs_clean_zn_cnt);
zbr->znode = znode;
znode->parent = parent;
znode->time = get_seconds();
znode->iip = iip;
return znode;
out:
kfree(znode);
return ERR_PTR(err);
}
/**
* ubifs_tnc_read_node - read a leaf node from the flash media.
* @c: UBIFS file-system description object
* @zbr: key and position of the node
* @node: node is returned here
*
* This function reads a node defined by @zbr from the flash media. Returns
* zero in case of success or a negative negative error code in case of
* failure.
*/
int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr,
void *node)
{
union ubifs_key key1, *key = &zbr->key;
int err, type = key_type(c, key);
struct ubifs_wbuf *wbuf;
/*
* 'zbr' has to point to on-flash node. The node may sit in a bud and
* may even be in a write buffer, so we have to take care about this.
*/
wbuf = ubifs_get_wbuf(c, zbr->lnum);
if (wbuf)
err = ubifs_read_node_wbuf(wbuf, node, type, zbr->len,
zbr->lnum, zbr->offs);
else
err = ubifs_read_node(c, node, type, zbr->len, zbr->lnum,
zbr->offs);
if (err) {
dbg_tnc("key %s", DBGKEY(key));
return err;
}
/* Make sure the key of the read node is correct */
key_read(c, key, &key1);
if (memcmp(node + UBIFS_KEY_OFFSET, &key1, c->key_len)) {
ubifs_err("bad key in node at LEB %d:%d",
zbr->lnum, zbr->offs);
dbg_tnc("looked for key %s found node's key %s",
DBGKEY(key), DBGKEY1(&key1));
dbg_dump_node(c, node);
return -EINVAL;
}
return 0;
}

745
fs/ubifs/ubifs-media.h Normal file
View File

@ -0,0 +1,745 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/*
* This file describes UBIFS on-flash format and contains definitions of all the
* relevant data structures and constants.
*
* All UBIFS on-flash objects are stored in the form of nodes. All nodes start
* with the UBIFS node magic number and have the same common header. Nodes
* always sit at 8-byte aligned positions on the media and node header sizes are
* also 8-byte aligned (except for the indexing node and the padding node).
*/
#ifndef __UBIFS_MEDIA_H__
#define __UBIFS_MEDIA_H__
/* UBIFS node magic number (must not have the padding byte first or last) */
#define UBIFS_NODE_MAGIC 0x06101831
/* UBIFS on-flash format version */
#define UBIFS_FORMAT_VERSION 4
/* Minimum logical eraseblock size in bytes */
#define UBIFS_MIN_LEB_SZ (15*1024)
/* Initial CRC32 value used when calculating CRC checksums */
#define UBIFS_CRC32_INIT 0xFFFFFFFFU
/*
* UBIFS does not try to compress data if its length is less than the below
* constant.
*/
#define UBIFS_MIN_COMPR_LEN 128
/* Root inode number */
#define UBIFS_ROOT_INO 1
/* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */
#define UBIFS_FIRST_INO 64
/*
* Maximum file name and extended attribute length (must be a multiple of 8,
* minus 1).
*/
#define UBIFS_MAX_NLEN 255
/* Maximum number of data journal heads */
#define UBIFS_MAX_JHEADS 1
/*
* Size of UBIFS data block. Note, UBIFS is not a block oriented file-system,
* which means that it does not treat the underlying media as consisting of
* blocks like in case of hard drives. Do not be confused. UBIFS block is just
* the maximum amount of data which one data node can have or which can be
* attached to an inode node.
*/
#define UBIFS_BLOCK_SIZE 4096
#define UBIFS_BLOCK_SHIFT 12
#define UBIFS_BLOCK_MASK 0x00000FFF
/* UBIFS padding byte pattern (must not be first or last byte of node magic) */
#define UBIFS_PADDING_BYTE 0xCE
/* Maximum possible key length */
#define UBIFS_MAX_KEY_LEN 16
/* Key length ("simple" format) */
#define UBIFS_SK_LEN 8
/* Minimum index tree fanout */
#define UBIFS_MIN_FANOUT 2
/* Maximum number of levels in UBIFS indexing B-tree */
#define UBIFS_MAX_LEVELS 512
/* Maximum amount of data attached to an inode in bytes */
#define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE
/* LEB Properties Tree fanout (must be power of 2) and fanout shift */
#define UBIFS_LPT_FANOUT 4
#define UBIFS_LPT_FANOUT_SHIFT 2
/* LEB Properties Tree bit field sizes */
#define UBIFS_LPT_CRC_BITS 16
#define UBIFS_LPT_CRC_BYTES 2
#define UBIFS_LPT_TYPE_BITS 4
/* The key is always at the same position in all keyed nodes */
#define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key)
/*
* LEB Properties Tree node types.
*
* UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties)
* UBIFS_LPT_NNODE: LPT internal node
* UBIFS_LPT_LTAB: LPT's own lprops table
* UBIFS_LPT_LSAVE: LPT's save table (big model only)
* UBIFS_LPT_NODE_CNT: count of LPT node types
* UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type
*/
enum {
UBIFS_LPT_PNODE,
UBIFS_LPT_NNODE,
UBIFS_LPT_LTAB,
UBIFS_LPT_LSAVE,
UBIFS_LPT_NODE_CNT,
UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1,
};
/*
* UBIFS inode types.
*
* UBIFS_ITYPE_REG: regular file
* UBIFS_ITYPE_DIR: directory
* UBIFS_ITYPE_LNK: soft link
* UBIFS_ITYPE_BLK: block device node
* UBIFS_ITYPE_CHR: character device node
* UBIFS_ITYPE_FIFO: fifo
* UBIFS_ITYPE_SOCK: socket
* UBIFS_ITYPES_CNT: count of supported file types
*/
enum {
UBIFS_ITYPE_REG,
UBIFS_ITYPE_DIR,
UBIFS_ITYPE_LNK,
UBIFS_ITYPE_BLK,
UBIFS_ITYPE_CHR,
UBIFS_ITYPE_FIFO,
UBIFS_ITYPE_SOCK,
UBIFS_ITYPES_CNT,
};
/*
* Supported key hash functions.
*
* UBIFS_KEY_HASH_R5: R5 hash
* UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name
*/
enum {
UBIFS_KEY_HASH_R5,
UBIFS_KEY_HASH_TEST,
};
/*
* Supported key formats.
*
* UBIFS_SIMPLE_KEY_FMT: simple key format
*/
enum {
UBIFS_SIMPLE_KEY_FMT,
};
/*
* The simple key format uses 29 bits for storing UBIFS block number and hash
* value.
*/
#define UBIFS_S_KEY_BLOCK_BITS 29
#define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF
#define UBIFS_S_KEY_HASH_BITS UBIFS_S_KEY_BLOCK_BITS
#define UBIFS_S_KEY_HASH_MASK UBIFS_S_KEY_BLOCK_MASK
/*
* Key types.
*
* UBIFS_INO_KEY: inode node key
* UBIFS_DATA_KEY: data node key
* UBIFS_DENT_KEY: directory entry node key
* UBIFS_XENT_KEY: extended attribute entry key
* UBIFS_KEY_TYPES_CNT: number of supported key types
*/
enum {
UBIFS_INO_KEY,
UBIFS_DATA_KEY,
UBIFS_DENT_KEY,
UBIFS_XENT_KEY,
UBIFS_KEY_TYPES_CNT,
};
/* Count of LEBs reserved for the superblock area */
#define UBIFS_SB_LEBS 1
/* Count of LEBs reserved for the master area */
#define UBIFS_MST_LEBS 2
/* First LEB of the superblock area */
#define UBIFS_SB_LNUM 0
/* First LEB of the master area */
#define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS)
/* First LEB of the log area */
#define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS)
/*
* The below constants define the absolute minimum values for various UBIFS
* media areas. Many of them actually depend of flash geometry and the FS
* configuration (number of journal heads, orphan LEBs, etc). This means that
* the smallest volume size which can be used for UBIFS cannot be pre-defined
* by these constants. The file-system that meets the below limitation will not
* necessarily mount. UBIFS does run-time calculations and validates the FS
* size.
*/
/* Minimum number of logical eraseblocks in the log */
#define UBIFS_MIN_LOG_LEBS 2
/* Minimum number of bud logical eraseblocks (one for each head) */
#define UBIFS_MIN_BUD_LEBS 3
/* Minimum number of journal logical eraseblocks */
#define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS)
/* Minimum number of LPT area logical eraseblocks */
#define UBIFS_MIN_LPT_LEBS 2
/* Minimum number of orphan area logical eraseblocks */
#define UBIFS_MIN_ORPH_LEBS 1
/*
* Minimum number of main area logical eraseblocks (buds, 2 for the index, 1
* for GC, 1 for deletions, and at least 1 for committed data).
*/
#define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 5)
/* Minimum number of logical eraseblocks */
#define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \
UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \
UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS)
/* Node sizes (N.B. these are guaranteed to be multiples of 8) */
#define UBIFS_CH_SZ sizeof(struct ubifs_ch)
#define UBIFS_INO_NODE_SZ sizeof(struct ubifs_ino_node)
#define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node)
#define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node)
#define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node)
#define UBIFS_PAD_NODE_SZ sizeof(struct ubifs_pad_node)
#define UBIFS_SB_NODE_SZ sizeof(struct ubifs_sb_node)
#define UBIFS_MST_NODE_SZ sizeof(struct ubifs_mst_node)
#define UBIFS_REF_NODE_SZ sizeof(struct ubifs_ref_node)
#define UBIFS_IDX_NODE_SZ sizeof(struct ubifs_idx_node)
#define UBIFS_CS_NODE_SZ sizeof(struct ubifs_cs_node)
#define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
/* Extended attribute entry nodes are identical to directory entry nodes */
#define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
/* Only this does not have to be multiple of 8 bytes */
#define UBIFS_BRANCH_SZ sizeof(struct ubifs_branch)
/* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */
#define UBIFS_MAX_DATA_NODE_SZ (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE)
#define UBIFS_MAX_INO_NODE_SZ (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA)
#define UBIFS_MAX_DENT_NODE_SZ (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1)
#define UBIFS_MAX_XENT_NODE_SZ UBIFS_MAX_DENT_NODE_SZ
/* The largest UBIFS node */
#define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
/*
* On-flash inode flags.
*
* UBIFS_COMPR_FL: use compression for this inode
* UBIFS_SYNC_FL: I/O on this inode has to be synchronous
* UBIFS_IMMUTABLE_FL: inode is immutable
* UBIFS_APPEND_FL: writes to the inode may only append data
* UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
* UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
*
* Note, these are on-flash flags which correspond to ioctl flags
* (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
* have to be the same.
*/
enum {
UBIFS_COMPR_FL = 0x01,
UBIFS_SYNC_FL = 0x02,
UBIFS_IMMUTABLE_FL = 0x04,
UBIFS_APPEND_FL = 0x08,
UBIFS_DIRSYNC_FL = 0x10,
UBIFS_XATTR_FL = 0x20,
};
/* Inode flag bits used by UBIFS */
#define UBIFS_FL_MASK 0x0000001F
/*
* UBIFS compression algorithms.
*
* UBIFS_COMPR_NONE: no compression
* UBIFS_COMPR_LZO: LZO compression
* UBIFS_COMPR_ZLIB: ZLIB compression
* UBIFS_COMPR_TYPES_CNT: count of supported compression types
*/
enum {
UBIFS_COMPR_NONE,
UBIFS_COMPR_LZO,
UBIFS_COMPR_ZLIB,
UBIFS_COMPR_TYPES_CNT,
};
/*
* UBIFS node types.
*
* UBIFS_INO_NODE: inode node
* UBIFS_DATA_NODE: data node
* UBIFS_DENT_NODE: directory entry node
* UBIFS_XENT_NODE: extended attribute node
* UBIFS_TRUN_NODE: truncation node
* UBIFS_PAD_NODE: padding node
* UBIFS_SB_NODE: superblock node
* UBIFS_MST_NODE: master node
* UBIFS_REF_NODE: LEB reference node
* UBIFS_IDX_NODE: index node
* UBIFS_CS_NODE: commit start node
* UBIFS_ORPH_NODE: orphan node
* UBIFS_NODE_TYPES_CNT: count of supported node types
*
* Note, we index arrays by these numbers, so keep them low and contiguous.
* Node type constants for inodes, direntries and so on have to be the same as
* corresponding key type constants.
*/
enum {
UBIFS_INO_NODE,
UBIFS_DATA_NODE,
UBIFS_DENT_NODE,
UBIFS_XENT_NODE,
UBIFS_TRUN_NODE,
UBIFS_PAD_NODE,
UBIFS_SB_NODE,
UBIFS_MST_NODE,
UBIFS_REF_NODE,
UBIFS_IDX_NODE,
UBIFS_CS_NODE,
UBIFS_ORPH_NODE,
UBIFS_NODE_TYPES_CNT,
};
/*
* Master node flags.
*
* UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
* UBIFS_MST_NO_ORPHS: no orphan inodes present
* UBIFS_MST_RCVRY: written by recovery
*/
enum {
UBIFS_MST_DIRTY = 1,
UBIFS_MST_NO_ORPHS = 2,
UBIFS_MST_RCVRY = 4,
};
/*
* Node group type (used by recovery to recover whole group or none).
*
* UBIFS_NO_NODE_GROUP: this node is not part of a group
* UBIFS_IN_NODE_GROUP: this node is a part of a group
* UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
*/
enum {
UBIFS_NO_NODE_GROUP = 0,
UBIFS_IN_NODE_GROUP,
UBIFS_LAST_OF_NODE_GROUP,
};
/*
* Superblock flags.
*
* UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
*/
enum {
UBIFS_FLG_BIGLPT = 0x02,
};
/**
* struct ubifs_ch - common header node.
* @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
* @crc: CRC-32 checksum of the node header
* @sqnum: sequence number
* @len: full node length
* @node_type: node type
* @group_type: node group type
* @padding: reserved for future, zeroes
*
* Every UBIFS node starts with this common part. If the node has a key, the
* key always goes next.
*/
struct ubifs_ch {
__le32 magic;
__le32 crc;
__le64 sqnum;
__le32 len;
__u8 node_type;
__u8 group_type;
__u8 padding[2];
} __attribute__ ((packed));
/**
* union ubifs_dev_desc - device node descriptor.
* @new: new type device descriptor
* @huge: huge type device descriptor
*
* This data structure describes major/minor numbers of a device node. In an
* inode is a device node then its data contains an object of this type. UBIFS
* uses standard Linux "new" and "huge" device node encodings.
*/
union ubifs_dev_desc {
__le32 new;
__le64 huge;
} __attribute__ ((packed));
/**
* struct ubifs_ino_node - inode node.
* @ch: common header
* @key: node key
* @creat_sqnum: sequence number at time of creation
* @size: inode size in bytes (amount of uncompressed data)
* @atime_sec: access time seconds
* @ctime_sec: creation time seconds
* @mtime_sec: modification time seconds
* @atime_nsec: access time nanoseconds
* @ctime_nsec: creation time nanoseconds
* @mtime_nsec: modification time nanoseconds
* @nlink: number of hard links
* @uid: owner ID
* @gid: group ID
* @mode: access flags
* @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
* @data_len: inode data length
* @xattr_cnt: count of extended attributes this inode has
* @xattr_size: summarized size of all extended attributes in bytes
* @padding1: reserved for future, zeroes
* @xattr_names: sum of lengths of all extended attribute names belonging to
* this inode
* @compr_type: compression type used for this inode
* @padding2: reserved for future, zeroes
* @data: data attached to the inode
*
* Note, even though inode compression type is defined by @compr_type, some
* nodes of this inode may be compressed with different compressor - this
* happens if compression type is changed while the inode already has data
* nodes. But @compr_type will be use for further writes to the inode.
*
* Note, do not forget to amend 'zero_ino_node_unused()' function when changing
* the padding fields.
*/
struct ubifs_ino_node {
struct ubifs_ch ch;
__u8 key[UBIFS_MAX_KEY_LEN];
__le64 creat_sqnum;
__le64 size;
__le64 atime_sec;
__le64 ctime_sec;
__le64 mtime_sec;
__le32 atime_nsec;
__le32 ctime_nsec;
__le32 mtime_nsec;
__le32 nlink;
__le32 uid;
__le32 gid;
__le32 mode;
__le32 flags;
__le32 data_len;
__le32 xattr_cnt;
__le32 xattr_size;
__u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
__le32 xattr_names;
__le16 compr_type;
__u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
__u8 data[];
} __attribute__ ((packed));
/**
* struct ubifs_dent_node - directory entry node.
* @ch: common header
* @key: node key
* @inum: target inode number
* @padding1: reserved for future, zeroes
* @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
* @nlen: name length
* @padding2: reserved for future, zeroes
* @name: zero-terminated name
*
* Note, do not forget to amend 'zero_dent_node_unused()' function when
* changing the padding fields.
*/
struct ubifs_dent_node {
struct ubifs_ch ch;
__u8 key[UBIFS_MAX_KEY_LEN];
__le64 inum;
__u8 padding1;
__u8 type;
__le16 nlen;
__u8 padding2[4]; /* Watch 'zero_dent_node_unused()' if changing! */
__u8 name[];
} __attribute__ ((packed));
/**
* struct ubifs_data_node - data node.
* @ch: common header
* @key: node key
* @size: uncompressed data size in bytes
* @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
* @padding: reserved for future, zeroes
* @data: data
*
* Note, do not forget to amend 'zero_data_node_unused()' function when
* changing the padding fields.
*/
struct ubifs_data_node {
struct ubifs_ch ch;
__u8 key[UBIFS_MAX_KEY_LEN];
__le32 size;
__le16 compr_type;
__u8 padding[2]; /* Watch 'zero_data_node_unused()' if changing! */
__u8 data[];
} __attribute__ ((packed));
/**
* struct ubifs_trun_node - truncation node.
* @ch: common header
* @inum: truncated inode number
* @padding: reserved for future, zeroes
* @old_size: size before truncation
* @new_size: size after truncation
*
* This node exists only in the journal and never goes to the main area. Note,
* do not forget to amend 'zero_trun_node_unused()' function when changing the
* padding fields.
*/
struct ubifs_trun_node {
struct ubifs_ch ch;
__le32 inum;
__u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
__le64 old_size;
__le64 new_size;
} __attribute__ ((packed));
/**
* struct ubifs_pad_node - padding node.
* @ch: common header
* @pad_len: how many bytes after this node are unused (because padded)
* @padding: reserved for future, zeroes
*/
struct ubifs_pad_node {
struct ubifs_ch ch;
__le32 pad_len;
} __attribute__ ((packed));
/**
* struct ubifs_sb_node - superblock node.
* @ch: common header
* @padding: reserved for future, zeroes
* @key_hash: type of hash function used in keys
* @key_fmt: format of the key
* @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
* @min_io_size: minimal input/output unit size
* @leb_size: logical eraseblock size in bytes
* @leb_cnt: count of LEBs used by file-system
* @max_leb_cnt: maximum count of LEBs used by file-system
* @max_bud_bytes: maximum amount of data stored in buds
* @log_lebs: log size in logical eraseblocks
* @lpt_lebs: number of LEBs used for lprops table
* @orph_lebs: number of LEBs used for recording orphans
* @jhead_cnt: count of journal heads
* @fanout: tree fanout (max. number of links per indexing node)
* @lsave_cnt: number of LEB numbers in LPT's save table
* @fmt_version: UBIFS on-flash format version
* @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
* @padding1: reserved for future, zeroes
* @rp_uid: reserve pool UID
* @rp_gid: reserve pool GID
* @rp_size: size of the reserved pool in bytes
* @padding2: reserved for future, zeroes
* @time_gran: time granularity in nanoseconds
* @uuid: UUID generated when the file system image was created
*/
struct ubifs_sb_node {
struct ubifs_ch ch;
__u8 padding[2];
__u8 key_hash;
__u8 key_fmt;
__le32 flags;
__le32 min_io_size;
__le32 leb_size;
__le32 leb_cnt;
__le32 max_leb_cnt;
__le64 max_bud_bytes;
__le32 log_lebs;
__le32 lpt_lebs;
__le32 orph_lebs;
__le32 jhead_cnt;
__le32 fanout;
__le32 lsave_cnt;
__le32 fmt_version;
__le16 default_compr;
__u8 padding1[2];
__le32 rp_uid;
__le32 rp_gid;
__le64 rp_size;
__le32 time_gran;
__u8 uuid[16];
__u8 padding2[3972];
} __attribute__ ((packed));
/**
* struct ubifs_mst_node - master node.
* @ch: common header
* @highest_inum: highest inode number in the committed index
* @cmt_no: commit number
* @flags: various flags (%UBIFS_MST_DIRTY, etc)
* @log_lnum: start of the log
* @root_lnum: LEB number of the root indexing node
* @root_offs: offset within @root_lnum
* @root_len: root indexing node length
* @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
* not reserved and should be reserved on mount)
* @ihead_lnum: LEB number of index head
* @ihead_offs: offset of index head
* @index_size: size of index on flash
* @total_free: total free space in bytes
* @total_dirty: total dirty space in bytes
* @total_used: total used space in bytes (includes only data LEBs)
* @total_dead: total dead space in bytes (includes only data LEBs)
* @total_dark: total dark space in bytes (includes only data LEBs)
* @lpt_lnum: LEB number of LPT root nnode
* @lpt_offs: offset of LPT root nnode
* @nhead_lnum: LEB number of LPT head
* @nhead_offs: offset of LPT head
* @ltab_lnum: LEB number of LPT's own lprops table
* @ltab_offs: offset of LPT's own lprops table
* @lsave_lnum: LEB number of LPT's save table (big model only)
* @lsave_offs: offset of LPT's save table (big model only)
* @lscan_lnum: LEB number of last LPT scan
* @empty_lebs: number of empty logical eraseblocks
* @idx_lebs: number of indexing logical eraseblocks
* @leb_cnt: count of LEBs used by file-system
* @padding: reserved for future, zeroes
*/
struct ubifs_mst_node {
struct ubifs_ch ch;
__le64 highest_inum;
__le64 cmt_no;
__le32 flags;
__le32 log_lnum;
__le32 root_lnum;
__le32 root_offs;
__le32 root_len;
__le32 gc_lnum;
__le32 ihead_lnum;
__le32 ihead_offs;
__le64 index_size;
__le64 total_free;
__le64 total_dirty;
__le64 total_used;
__le64 total_dead;
__le64 total_dark;
__le32 lpt_lnum;
__le32 lpt_offs;
__le32 nhead_lnum;
__le32 nhead_offs;
__le32 ltab_lnum;
__le32 ltab_offs;
__le32 lsave_lnum;
__le32 lsave_offs;
__le32 lscan_lnum;
__le32 empty_lebs;
__le32 idx_lebs;
__le32 leb_cnt;
__u8 padding[344];
} __attribute__ ((packed));
/**
* struct ubifs_ref_node - logical eraseblock reference node.
* @ch: common header
* @lnum: the referred logical eraseblock number
* @offs: start offset in the referred LEB
* @jhead: journal head number
* @padding: reserved for future, zeroes
*/
struct ubifs_ref_node {
struct ubifs_ch ch;
__le32 lnum;
__le32 offs;
__le32 jhead;
__u8 padding[28];
} __attribute__ ((packed));
/**
* struct ubifs_branch - key/reference/length branch
* @lnum: LEB number of the target node
* @offs: offset within @lnum
* @len: target node length
* @key: key
*/
struct ubifs_branch {
__le32 lnum;
__le32 offs;
__le32 len;
__u8 key[];
} __attribute__ ((packed));
/**
* struct ubifs_idx_node - indexing node.
* @ch: common header
* @child_cnt: number of child index nodes
* @level: tree level
* @branches: LEB number / offset / length / key branches
*/
struct ubifs_idx_node {
struct ubifs_ch ch;
__le16 child_cnt;
__le16 level;
__u8 branches[];
} __attribute__ ((packed));
/**
* struct ubifs_cs_node - commit start node.
* @ch: common header
* @cmt_no: commit number
*/
struct ubifs_cs_node {
struct ubifs_ch ch;
__le64 cmt_no;
} __attribute__ ((packed));
/**
* struct ubifs_orph_node - orphan node.
* @ch: common header
* @cmt_no: commit number (also top bit is set on the last node of the commit)
* @inos: inode numbers of orphans
*/
struct ubifs_orph_node {
struct ubifs_ch ch;
__le64 cmt_no;
__le64 inos[];
} __attribute__ ((packed));
#endif /* __UBIFS_MEDIA_H__ */

1649
fs/ubifs/ubifs.h Normal file
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581
fs/ubifs/xattr.c Normal file
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@ -0,0 +1,581 @@
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/*
* This file implements UBIFS extended attributes support.
*
* Extended attributes are implemented as regular inodes with attached data,
* which limits extended attribute size to UBIFS block size (4KiB). Names of
* extended attributes are described by extended attribute entries (xentries),
* which are almost identical to directory entries, but have different key type.
*
* In other words, the situation with extended attributes is very similar to
* directories. Indeed, any inode (but of course not xattr inodes) may have a
* number of associated xentries, just like directory inodes have associated
* directory entries. Extended attribute entries store the name of the extended
* attribute, the host inode number, and the extended attribute inode number.
* Similarly, direntries store the name, the parent and the target inode
* numbers. Thus, most of the common UBIFS mechanisms may be re-used for
* extended attributes.
*
* The number of extended attributes is not limited, but there is Linux
* limitation on the maximum possible size of the list of all extended
* attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure
* the sum of all extended attribute names of the inode does not exceed that
* limit.
*
* Extended attributes are synchronous, which means they are written to the
* flash media synchronously and there is no write-back for extended attribute
* inodes. The extended attribute values are not stored in compressed form on
* the media.
*
* Since extended attributes are represented by regular inodes, they are cached
* in the VFS inode cache. The xentries are cached in the LNC cache (see
* tnc.c).
*
* ACL support is not implemented.
*/
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include "ubifs.h"
/*
* Limit the number of extended attributes per inode so that the total size
* (xattr_size) is guaranteeded to fit in an 'unsigned int'.
*/
#define MAX_XATTRS_PER_INODE 65535
/*
* Extended attribute type constants.
*
* USER_XATTR: user extended attribute ("user.*")
* TRUSTED_XATTR: trusted extended attribute ("trusted.*)
* SECURITY_XATTR: security extended attribute ("security.*")
*/
enum {
USER_XATTR,
TRUSTED_XATTR,
SECURITY_XATTR,
};
static struct inode_operations none_inode_operations;
static struct address_space_operations none_address_operations;
static struct file_operations none_file_operations;
/**
* create_xattr - create an extended attribute.
* @c: UBIFS file-system description object
* @host: host inode
* @nm: extended attribute name
* @value: extended attribute value
* @size: size of extended attribute value
*
* This is a helper function which creates an extended attribute of name @nm
* and value @value for inode @host. The host inode is also updated on flash
* because the ctime and extended attribute accounting data changes. This
* function returns zero in case of success and a negative error code in case
* of failure.
*/
static int create_xattr(struct ubifs_info *c, struct inode *host,
const struct qstr *nm, const void *value, int size)
{
int err;
struct inode *inode;
struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
.new_ino_d = size, .dirtied_ino = 1,
.dirtied_ino_d = host_ui->data_len};
if (host_ui->xattr_cnt >= MAX_XATTRS_PER_INODE)
return -ENOSPC;
/*
* Linux limits the maximum size of the extended attribute names list
* to %XATTR_LIST_MAX. This means we should not allow creating more*
* extended attributes if the name list becomes larger. This limitation
* is artificial for UBIFS, though.
*/
if (host_ui->xattr_names + host_ui->xattr_cnt +
nm->len + 1 > XATTR_LIST_MAX)
return -ENOSPC;
err = ubifs_budget_space(c, &req);
if (err)
return err;
inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_budg;
}
mutex_lock(&host_ui->ui_mutex);
/* Re-define all operations to be "nothing" */
inode->i_mapping->a_ops = &none_address_operations;
inode->i_op = &none_inode_operations;
inode->i_fop = &none_file_operations;
inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME | S_NOQUOTA;
ui = ubifs_inode(inode);
ui->xattr = 1;
ui->flags |= UBIFS_XATTR_FL;
ui->data = kmalloc(size, GFP_NOFS);
if (!ui->data) {
err = -ENOMEM;
goto out_unlock;
}
memcpy(ui->data, value, size);
host->i_ctime = ubifs_current_time(host);
host_ui->xattr_cnt += 1;
host_ui->xattr_size += CALC_DENT_SIZE(nm->len);
host_ui->xattr_size += CALC_XATTR_BYTES(size);
host_ui->xattr_names += nm->len;
/*
* We do not use i_size_write() because nobody can race with us as we
* are holding host @host->i_mutex - every xattr operation for this
* inode is serialized by it.
*/
inode->i_size = ui->ui_size = size;
ui->data_len = size;
err = ubifs_jnl_update(c, host, nm, inode, 0, 1);
if (err)
goto out_cancel;
mutex_unlock(&host_ui->ui_mutex);
ubifs_release_budget(c, &req);
insert_inode_hash(inode);
iput(inode);
return 0;
out_cancel:
host_ui->xattr_cnt -= 1;
host_ui->xattr_size -= CALC_DENT_SIZE(nm->len);
host_ui->xattr_size -= CALC_XATTR_BYTES(size);
out_unlock:
mutex_unlock(&host_ui->ui_mutex);
make_bad_inode(inode);
iput(inode);
out_budg:
ubifs_release_budget(c, &req);
return err;
}
/**
* change_xattr - change an extended attribute.
* @c: UBIFS file-system description object
* @host: host inode
* @inode: extended attribute inode
* @value: extended attribute value
* @size: size of extended attribute value
*
* This helper function changes the value of extended attribute @inode with new
* data from @value. Returns zero in case of success and a negative error code
* in case of failure.
*/
static int change_xattr(struct ubifs_info *c, struct inode *host,
struct inode *inode, const void *value, int size)
{
int err;
struct ubifs_inode *host_ui = ubifs_inode(host);
struct ubifs_inode *ui = ubifs_inode(inode);
struct ubifs_budget_req req = { .dirtied_ino = 2,
.dirtied_ino_d = size + host_ui->data_len };
ubifs_assert(ui->data_len == inode->i_size);
err = ubifs_budget_space(c, &req);
if (err)
return err;
mutex_lock(&host_ui->ui_mutex);
host->i_ctime = ubifs_current_time(host);
host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
host_ui->xattr_size += CALC_XATTR_BYTES(size);
kfree(ui->data);
ui->data = kmalloc(size, GFP_NOFS);
if (!ui->data) {
err = -ENOMEM;
goto out_unlock;
}
memcpy(ui->data, value, size);
inode->i_size = ui->ui_size = size;
ui->data_len = size;
/*
* It is important to write the host inode after the xattr inode
* because if the host inode gets synchronized (via 'fsync()'), then
* the extended attribute inode gets synchronized, because it goes
* before the host inode in the write-buffer.
*/
err = ubifs_jnl_change_xattr(c, inode, host);
if (err)
goto out_cancel;
mutex_unlock(&host_ui->ui_mutex);
ubifs_release_budget(c, &req);
return 0;
out_cancel:
host_ui->xattr_size -= CALC_XATTR_BYTES(size);
host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
make_bad_inode(inode);
out_unlock:
mutex_unlock(&host_ui->ui_mutex);
ubifs_release_budget(c, &req);
return err;
}
/**
* check_namespace - check extended attribute name-space.
* @nm: extended attribute name
*
* This function makes sure the extended attribute name belongs to one of the
* supported extended attribute name-spaces. Returns name-space index in case
* of success and a negative error code in case of failure.
*/
static int check_namespace(const struct qstr *nm)
{
int type;
if (nm->len > UBIFS_MAX_NLEN)
return -ENAMETOOLONG;
if (!strncmp(nm->name, XATTR_TRUSTED_PREFIX,
XATTR_TRUSTED_PREFIX_LEN)) {
if (nm->name[sizeof(XATTR_TRUSTED_PREFIX) - 1] == '\0')
return -EINVAL;
type = TRUSTED_XATTR;
} else if (!strncmp(nm->name, XATTR_USER_PREFIX,
XATTR_USER_PREFIX_LEN)) {
if (nm->name[XATTR_USER_PREFIX_LEN] == '\0')
return -EINVAL;
type = USER_XATTR;
} else if (!strncmp(nm->name, XATTR_SECURITY_PREFIX,
XATTR_SECURITY_PREFIX_LEN)) {
if (nm->name[sizeof(XATTR_SECURITY_PREFIX) - 1] == '\0')
return -EINVAL;
type = SECURITY_XATTR;
} else
return -EOPNOTSUPP;
return type;
}
static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
{
struct inode *inode;
inode = ubifs_iget(c->vfs_sb, inum);
if (IS_ERR(inode)) {
ubifs_err("dead extended attribute entry, error %d",
(int)PTR_ERR(inode));
return inode;
}
if (ubifs_inode(inode)->xattr)
return inode;
ubifs_err("corrupt extended attribute entry");
iput(inode);
return ERR_PTR(-EINVAL);
}
int ubifs_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct inode *inode, *host = dentry->d_inode;
struct ubifs_info *c = host->i_sb->s_fs_info;
struct qstr nm = { .name = name, .len = strlen(name) };
struct ubifs_dent_node *xent;
union ubifs_key key;
int err, type;
dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name,
host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
if (size > UBIFS_MAX_INO_DATA)
return -ERANGE;
type = check_namespace(&nm);
if (type < 0)
return type;
xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
if (!xent)
return -ENOMEM;
/*
* The extended attribute entries are stored in LNC, so multiple
* look-ups do not involve reading the flash.
*/
xent_key_init(c, &key, host->i_ino, &nm);
err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
if (err) {
if (err != -ENOENT)
goto out_free;
if (flags & XATTR_REPLACE)
/* We are asked not to create the xattr */
err = -ENODATA;
else
err = create_xattr(c, host, &nm, value, size);
goto out_free;
}
if (flags & XATTR_CREATE) {
/* We are asked not to replace the xattr */
err = -EEXIST;
goto out_free;
}
inode = iget_xattr(c, le64_to_cpu(xent->inum));
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_free;
}
err = change_xattr(c, host, inode, value, size);
iput(inode);
out_free:
kfree(xent);
return err;
}
ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
size_t size)
{
struct inode *inode, *host = dentry->d_inode;
struct ubifs_info *c = host->i_sb->s_fs_info;
struct qstr nm = { .name = name, .len = strlen(name) };
struct ubifs_inode *ui;
struct ubifs_dent_node *xent;
union ubifs_key key;
int err;
dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name,
host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
err = check_namespace(&nm);
if (err < 0)
return err;
xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
if (!xent)
return -ENOMEM;
mutex_lock(&host->i_mutex);
xent_key_init(c, &key, host->i_ino, &nm);
err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
if (err) {
if (err == -ENOENT)
err = -ENODATA;
goto out_unlock;
}
inode = iget_xattr(c, le64_to_cpu(xent->inum));
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_unlock;
}
ui = ubifs_inode(inode);
ubifs_assert(inode->i_size == ui->data_len);
ubifs_assert(ubifs_inode(host)->xattr_size > ui->data_len);
if (buf) {
/* If @buf is %NULL we are supposed to return the length */
if (ui->data_len > size) {
dbg_err("buffer size %zd, xattr len %d",
size, ui->data_len);
err = -ERANGE;
goto out_iput;
}
memcpy(buf, ui->data, ui->data_len);
}
err = ui->data_len;
out_iput:
iput(inode);
out_unlock:
mutex_unlock(&host->i_mutex);
kfree(xent);
return err;
}
ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
union ubifs_key key;
struct inode *host = dentry->d_inode;
struct ubifs_info *c = host->i_sb->s_fs_info;
struct ubifs_inode *host_ui = ubifs_inode(host);
struct ubifs_dent_node *xent, *pxent = NULL;
int err, len, written = 0;
struct qstr nm = { .name = NULL };
dbg_gen("ino %lu ('%.*s'), buffer size %zd", host->i_ino,
dentry->d_name.len, dentry->d_name.name, size);
len = host_ui->xattr_names + host_ui->xattr_cnt;
if (!buffer)
/*
* We should return the minimum buffer size which will fit a
* null-terminated list of all the extended attribute names.
*/
return len;
if (len > size)
return -ERANGE;
lowest_xent_key(c, &key, host->i_ino);
mutex_lock(&host->i_mutex);
while (1) {
int type;
xent = ubifs_tnc_next_ent(c, &key, &nm);
if (unlikely(IS_ERR(xent))) {
err = PTR_ERR(xent);
break;
}
nm.name = xent->name;
nm.len = le16_to_cpu(xent->nlen);
type = check_namespace(&nm);
if (unlikely(type < 0)) {
err = type;
break;
}
/* Show trusted namespace only for "power" users */
if (type != TRUSTED_XATTR || capable(CAP_SYS_ADMIN)) {
memcpy(buffer + written, nm.name, nm.len + 1);
written += nm.len + 1;
}
kfree(pxent);
pxent = xent;
key_read(c, &xent->key, &key);
}
mutex_unlock(&host->i_mutex);
kfree(pxent);
if (err != -ENOENT) {
ubifs_err("cannot find next direntry, error %d", err);
return err;
}
ubifs_assert(written <= size);
return written;
}
static int remove_xattr(struct ubifs_info *c, struct inode *host,
struct inode *inode, const struct qstr *nm)
{
int err;
struct ubifs_inode *host_ui = ubifs_inode(host);
struct ubifs_inode *ui = ubifs_inode(inode);
struct ubifs_budget_req req = { .dirtied_ino = 1, .mod_dent = 1,
.dirtied_ino_d = host_ui->data_len };
ubifs_assert(ui->data_len == inode->i_size);
err = ubifs_budget_space(c, &req);
if (err)
return err;
mutex_lock(&host_ui->ui_mutex);
host->i_ctime = ubifs_current_time(host);
host_ui->xattr_cnt -= 1;
host_ui->xattr_size -= CALC_DENT_SIZE(nm->len);
host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
host_ui->xattr_names -= nm->len;
err = ubifs_jnl_delete_xattr(c, host, inode, nm);
if (err)
goto out_cancel;
mutex_unlock(&host_ui->ui_mutex);
ubifs_release_budget(c, &req);
return 0;
out_cancel:
host_ui->xattr_cnt += 1;
host_ui->xattr_size += CALC_DENT_SIZE(nm->len);
host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
mutex_unlock(&host_ui->ui_mutex);
ubifs_release_budget(c, &req);
make_bad_inode(inode);
return err;
}
int ubifs_removexattr(struct dentry *dentry, const char *name)
{
struct inode *inode, *host = dentry->d_inode;
struct ubifs_info *c = host->i_sb->s_fs_info;
struct qstr nm = { .name = name, .len = strlen(name) };
struct ubifs_dent_node *xent;
union ubifs_key key;
int err;
dbg_gen("xattr '%s', ino %lu ('%.*s')", name,
host->i_ino, dentry->d_name.len, dentry->d_name.name);
ubifs_assert(mutex_is_locked(&host->i_mutex));
err = check_namespace(&nm);
if (err < 0)
return err;
xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
if (!xent)
return -ENOMEM;
xent_key_init(c, &key, host->i_ino, &nm);
err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
if (err) {
if (err == -ENOENT)
err = -ENODATA;
goto out_free;
}
inode = iget_xattr(c, le64_to_cpu(xent->inum));
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_free;
}
ubifs_assert(inode->i_nlink == 1);
inode->i_nlink = 0;
err = remove_xattr(c, host, inode, &nm);
if (err)
inode->i_nlink = 1;
/* If @i_nlink is 0, 'iput()' will delete the inode */
iput(inode);
out_free:
kfree(xent);
return err;
}