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linux_dsm_epyc7002/fs/btrfs/extent-tree.c
Josef Bacik 2b9dbef272 Btrfs: keep dropped roots in cache until transaction commit 
When dropping a snapshot we need to account for the qgroup changes.  If we drop
the snapshot in all one go then the backref code will fail to find blocks from
the snapshot we dropped since it won't be able to find the root in the fs root
cache.  This can lead to us failing to find refs from other roots that pointed
at blocks in the now deleted root.  To handle this we need to not remove the fs
roots from the cache until after we process the qgroup operations.  Do this by
adding dropped roots to a list on the transaction, and letting the transaction
remove the roots at the same time it drops the commit roots.  This will keep all
of the backref searching code in sync properly, and fixes a problem Mark was
seeing with snapshot delete and qgroups.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com>
Signed-off-by: Chris Mason <clm@fb.com>
2015-09-22 10:22:56 -07:00

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 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., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/blkdev.h>
#include <linux/sort.h>
#include <linux/rcupdate.h>
#include <linux/kthread.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/percpu_counter.h>
#include "hash.h"
#include "tree-log.h"
#include "disk-io.h"
#include "print-tree.h"
#include "volumes.h"
#include "raid56.h"
#include "locking.h"
#include "free-space-cache.h"
#include "math.h"
#include "sysfs.h"
#include "qgroup.h"
#undef SCRAMBLE_DELAYED_REFS
/*
* control flags for do_chunk_alloc's force field
* CHUNK_ALLOC_NO_FORCE means to only allocate a chunk
* if we really need one.
*
* CHUNK_ALLOC_LIMITED means to only try and allocate one
* if we have very few chunks already allocated. This is
* used as part of the clustering code to help make sure
* we have a good pool of storage to cluster in, without
* filling the FS with empty chunks
*
* CHUNK_ALLOC_FORCE means it must try to allocate one
*
*/
enum {
CHUNK_ALLOC_NO_FORCE = 0,
CHUNK_ALLOC_LIMITED = 1,
CHUNK_ALLOC_FORCE = 2,
};
/*
* Control how reservations are dealt with.
*
* RESERVE_FREE - freeing a reservation.
* RESERVE_ALLOC - allocating space and we need to update bytes_may_use for
* ENOSPC accounting
* RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update
* bytes_may_use as the ENOSPC accounting is done elsewhere
*/
enum {
RESERVE_FREE = 0,
RESERVE_ALLOC = 1,
RESERVE_ALLOC_NO_ACCOUNT = 2,
};
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 num_bytes, int alloc);
static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node, u64 parent,
u64 root_objectid, u64 owner_objectid,
u64 owner_offset, int refs_to_drop,
struct btrfs_delayed_extent_op *extra_op);
static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
struct extent_buffer *leaf,
struct btrfs_extent_item *ei);
static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, u64 owner, u64 offset,
struct btrfs_key *ins, int ref_mod);
static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, struct btrfs_disk_key *key,
int level, struct btrfs_key *ins,
int no_quota);
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 flags,
int force);
static int find_next_key(struct btrfs_path *path, int level,
struct btrfs_key *key);
static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
int dump_block_groups);
static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
u64 num_bytes, int reserve,
int delalloc);
static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
u64 num_bytes);
int btrfs_pin_extent(struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int reserved);
static noinline int
block_group_cache_done(struct btrfs_block_group_cache *cache)
{
smp_mb();
return cache->cached == BTRFS_CACHE_FINISHED ||
cache->cached == BTRFS_CACHE_ERROR;
}
static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits)
{
return (cache->flags & bits) == bits;
}
static void btrfs_get_block_group(struct btrfs_block_group_cache *cache)
{
atomic_inc(&cache->count);
}
void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
{
if (atomic_dec_and_test(&cache->count)) {
WARN_ON(cache->pinned > 0);
WARN_ON(cache->reserved > 0);
kfree(cache->free_space_ctl);
kfree(cache);
}
}
/*
* this adds the block group to the fs_info rb tree for the block group
* cache
*/
static int btrfs_add_block_group_cache(struct btrfs_fs_info *info,
struct btrfs_block_group_cache *block_group)
{
struct rb_node **p;
struct rb_node *parent = NULL;
struct btrfs_block_group_cache *cache;
spin_lock(&info->block_group_cache_lock);
p = &info->block_group_cache_tree.rb_node;
while (*p) {
parent = *p;
cache = rb_entry(parent, struct btrfs_block_group_cache,
cache_node);
if (block_group->key.objectid < cache->key.objectid) {
p = &(*p)->rb_left;
} else if (block_group->key.objectid > cache->key.objectid) {
p = &(*p)->rb_right;
} else {
spin_unlock(&info->block_group_cache_lock);
return -EEXIST;
}
}
rb_link_node(&block_group->cache_node, parent, p);
rb_insert_color(&block_group->cache_node,
&info->block_group_cache_tree);
if (info->first_logical_byte > block_group->key.objectid)
info->first_logical_byte = block_group->key.objectid;
spin_unlock(&info->block_group_cache_lock);
return 0;
}
/*
* This will return the block group at or after bytenr if contains is 0, else
* it will return the block group that contains the bytenr
*/
static struct btrfs_block_group_cache *
block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr,
int contains)
{
struct btrfs_block_group_cache *cache, *ret = NULL;
struct rb_node *n;
u64 end, start;
spin_lock(&info->block_group_cache_lock);
n = info->block_group_cache_tree.rb_node;
while (n) {
cache = rb_entry(n, struct btrfs_block_group_cache,
cache_node);
end = cache->key.objectid + cache->key.offset - 1;
start = cache->key.objectid;
if (bytenr < start) {
if (!contains && (!ret || start < ret->key.objectid))
ret = cache;
n = n->rb_left;
} else if (bytenr > start) {
if (contains && bytenr <= end) {
ret = cache;
break;
}
n = n->rb_right;
} else {
ret = cache;
break;
}
}
if (ret) {
btrfs_get_block_group(ret);
if (bytenr == 0 && info->first_logical_byte > ret->key.objectid)
info->first_logical_byte = ret->key.objectid;
}
spin_unlock(&info->block_group_cache_lock);
return ret;
}
static int add_excluded_extent(struct btrfs_root *root,
u64 start, u64 num_bytes)
{
u64 end = start + num_bytes - 1;
set_extent_bits(&root->fs_info->freed_extents[0],
start, end, EXTENT_UPTODATE, GFP_NOFS);
set_extent_bits(&root->fs_info->freed_extents[1],
start, end, EXTENT_UPTODATE, GFP_NOFS);
return 0;
}
static void free_excluded_extents(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
u64 start, end;
start = cache->key.objectid;
end = start + cache->key.offset - 1;
clear_extent_bits(&root->fs_info->freed_extents[0],
start, end, EXTENT_UPTODATE, GFP_NOFS);
clear_extent_bits(&root->fs_info->freed_extents[1],
start, end, EXTENT_UPTODATE, GFP_NOFS);
}
static int exclude_super_stripes(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
u64 bytenr;
u64 *logical;
int stripe_len;
int i, nr, ret;
if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) {
stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid;
cache->bytes_super += stripe_len;
ret = add_excluded_extent(root, cache->key.objectid,
stripe_len);
if (ret)
return ret;
}
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
cache->key.objectid, bytenr,
0, &logical, &nr, &stripe_len);
if (ret)
return ret;
while (nr--) {
u64 start, len;
if (logical[nr] > cache->key.objectid +
cache->key.offset)
continue;
if (logical[nr] + stripe_len <= cache->key.objectid)
continue;
start = logical[nr];
if (start < cache->key.objectid) {
start = cache->key.objectid;
len = (logical[nr] + stripe_len) - start;
} else {
len = min_t(u64, stripe_len,
cache->key.objectid +
cache->key.offset - start);
}
cache->bytes_super += len;
ret = add_excluded_extent(root, start, len);
if (ret) {
kfree(logical);
return ret;
}
}
kfree(logical);
}
return 0;
}
static struct btrfs_caching_control *
get_caching_control(struct btrfs_block_group_cache *cache)
{
struct btrfs_caching_control *ctl;
spin_lock(&cache->lock);
if (!cache->caching_ctl) {
spin_unlock(&cache->lock);
return NULL;
}
ctl = cache->caching_ctl;
atomic_inc(&ctl->count);
spin_unlock(&cache->lock);
return ctl;
}
static void put_caching_control(struct btrfs_caching_control *ctl)
{
if (atomic_dec_and_test(&ctl->count))
kfree(ctl);
}
/*
* this is only called by cache_block_group, since we could have freed extents
* we need to check the pinned_extents for any extents that can't be used yet
* since their free space will be released as soon as the transaction commits.
*/
static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
struct btrfs_fs_info *info, u64 start, u64 end)
{
u64 extent_start, extent_end, size, total_added = 0;
int ret;
while (start < end) {
ret = find_first_extent_bit(info->pinned_extents, start,
&extent_start, &extent_end,
EXTENT_DIRTY | EXTENT_UPTODATE,
NULL);
if (ret)
break;
if (extent_start <= start) {
start = extent_end + 1;
} else if (extent_start > start && extent_start < end) {
size = extent_start - start;
total_added += size;
ret = btrfs_add_free_space(block_group, start,
size);
BUG_ON(ret); /* -ENOMEM or logic error */
start = extent_end + 1;
} else {
break;
}
}
if (start < end) {
size = end - start;
total_added += size;
ret = btrfs_add_free_space(block_group, start, size);
BUG_ON(ret); /* -ENOMEM or logic error */
}
return total_added;
}
static noinline void caching_thread(struct btrfs_work *work)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_fs_info *fs_info;
struct btrfs_caching_control *caching_ctl;
struct btrfs_root *extent_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key;
u64 total_found = 0;
u64 last = 0;
u32 nritems;
int ret = -ENOMEM;
caching_ctl = container_of(work, struct btrfs_caching_control, work);
block_group = caching_ctl->block_group;
fs_info = block_group->fs_info;
extent_root = fs_info->extent_root;
path = btrfs_alloc_path();
if (!path)
goto out;
last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
/*
* We don't want to deadlock with somebody trying to allocate a new
* extent for the extent root while also trying to search the extent
* root to add free space. So we skip locking and search the commit
* root, since its read-only
*/
path->skip_locking = 1;
path->search_commit_root = 1;
path->reada = 1;
key.objectid = last;
key.offset = 0;
key.type = BTRFS_EXTENT_ITEM_KEY;
again:
mutex_lock(&caching_ctl->mutex);
/* need to make sure the commit_root doesn't disappear */
down_read(&fs_info->commit_root_sem);
next:
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto err;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
while (1) {
if (btrfs_fs_closing(fs_info) > 1) {
last = (u64)-1;
break;
}
if (path->slots[0] < nritems) {
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
} else {
ret = find_next_key(path, 0, &key);
if (ret)
break;
if (need_resched() ||
rwsem_is_contended(&fs_info->commit_root_sem)) {
caching_ctl->progress = last;
btrfs_release_path(path);
up_read(&fs_info->commit_root_sem);
mutex_unlock(&caching_ctl->mutex);
cond_resched();
goto again;
}
ret = btrfs_next_leaf(extent_root, path);
if (ret < 0)
goto err;
if (ret)
break;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
continue;
}
if (key.objectid < last) {
key.objectid = last;
key.offset = 0;
key.type = BTRFS_EXTENT_ITEM_KEY;
caching_ctl->progress = last;
btrfs_release_path(path);
goto next;
}
if (key.objectid < block_group->key.objectid) {
path->slots[0]++;
continue;
}
if (key.objectid >= block_group->key.objectid +
block_group->key.offset)
break;
if (key.type == BTRFS_EXTENT_ITEM_KEY ||
key.type == BTRFS_METADATA_ITEM_KEY) {
total_found += add_new_free_space(block_group,
fs_info, last,
key.objectid);
if (key.type == BTRFS_METADATA_ITEM_KEY)
last = key.objectid +
fs_info->tree_root->nodesize;
else
last = key.objectid + key.offset;
if (total_found > (1024 * 1024 * 2)) {
total_found = 0;
wake_up(&caching_ctl->wait);
}
}
path->slots[0]++;
}
ret = 0;
total_found += add_new_free_space(block_group, fs_info, last,
block_group->key.objectid +
block_group->key.offset);
caching_ctl->progress = (u64)-1;
spin_lock(&block_group->lock);
block_group->caching_ctl = NULL;
block_group->cached = BTRFS_CACHE_FINISHED;
spin_unlock(&block_group->lock);
err:
btrfs_free_path(path);
up_read(&fs_info->commit_root_sem);
free_excluded_extents(extent_root, block_group);
mutex_unlock(&caching_ctl->mutex);
out:
if (ret) {
spin_lock(&block_group->lock);
block_group->caching_ctl = NULL;
block_group->cached = BTRFS_CACHE_ERROR;
spin_unlock(&block_group->lock);
}
wake_up(&caching_ctl->wait);
put_caching_control(caching_ctl);
btrfs_put_block_group(block_group);
}
static int cache_block_group(struct btrfs_block_group_cache *cache,
int load_cache_only)
{
DEFINE_WAIT(wait);
struct btrfs_fs_info *fs_info = cache->fs_info;
struct btrfs_caching_control *caching_ctl;
int ret = 0;
caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
if (!caching_ctl)
return -ENOMEM;
INIT_LIST_HEAD(&caching_ctl->list);
mutex_init(&caching_ctl->mutex);
init_waitqueue_head(&caching_ctl->wait);
caching_ctl->block_group = cache;
caching_ctl->progress = cache->key.objectid;
atomic_set(&caching_ctl->count, 1);
btrfs_init_work(&caching_ctl->work, btrfs_cache_helper,
caching_thread, NULL, NULL);
spin_lock(&cache->lock);
/*
* This should be a rare occasion, but this could happen I think in the
* case where one thread starts to load the space cache info, and then
* some other thread starts a transaction commit which tries to do an
* allocation while the other thread is still loading the space cache
* info. The previous loop should have kept us from choosing this block
* group, but if we've moved to the state where we will wait on caching
* block groups we need to first check if we're doing a fast load here,
* so we can wait for it to finish, otherwise we could end up allocating
* from a block group who's cache gets evicted for one reason or
* another.
*/
while (cache->cached == BTRFS_CACHE_FAST) {
struct btrfs_caching_control *ctl;
ctl = cache->caching_ctl;
atomic_inc(&ctl->count);
prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE);
spin_unlock(&cache->lock);
schedule();
finish_wait(&ctl->wait, &wait);
put_caching_control(ctl);
spin_lock(&cache->lock);
}
if (cache->cached != BTRFS_CACHE_NO) {
spin_unlock(&cache->lock);
kfree(caching_ctl);
return 0;
}
WARN_ON(cache->caching_ctl);
cache->caching_ctl = caching_ctl;
cache->cached = BTRFS_CACHE_FAST;
spin_unlock(&cache->lock);
if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) {
mutex_lock(&caching_ctl->mutex);
ret = load_free_space_cache(fs_info, cache);
spin_lock(&cache->lock);
if (ret == 1) {
cache->caching_ctl = NULL;
cache->cached = BTRFS_CACHE_FINISHED;
cache->last_byte_to_unpin = (u64)-1;
caching_ctl->progress = (u64)-1;
} else {
if (load_cache_only) {
cache->caching_ctl = NULL;
cache->cached = BTRFS_CACHE_NO;
} else {
cache->cached = BTRFS_CACHE_STARTED;
cache->has_caching_ctl = 1;
}
}
spin_unlock(&cache->lock);
mutex_unlock(&caching_ctl->mutex);
wake_up(&caching_ctl->wait);
if (ret == 1) {
put_caching_control(caching_ctl);
free_excluded_extents(fs_info->extent_root, cache);
return 0;
}
} else {
/*
* We are not going to do the fast caching, set cached to the
* appropriate value and wakeup any waiters.
*/
spin_lock(&cache->lock);
if (load_cache_only) {
cache->caching_ctl = NULL;
cache->cached = BTRFS_CACHE_NO;
} else {
cache->cached = BTRFS_CACHE_STARTED;
cache->has_caching_ctl = 1;
}
spin_unlock(&cache->lock);
wake_up(&caching_ctl->wait);
}
if (load_cache_only) {
put_caching_control(caching_ctl);
return 0;
}
down_write(&fs_info->commit_root_sem);
atomic_inc(&caching_ctl->count);
list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups);
up_write(&fs_info->commit_root_sem);
btrfs_get_block_group(cache);
btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work);
return ret;
}
/*
* return the block group that starts at or after bytenr
*/
static struct btrfs_block_group_cache *
btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr)
{
struct btrfs_block_group_cache *cache;
cache = block_group_cache_tree_search(info, bytenr, 0);
return cache;
}
/*
* return the block group that contains the given bytenr
*/
struct btrfs_block_group_cache *btrfs_lookup_block_group(
struct btrfs_fs_info *info,
u64 bytenr)
{
struct btrfs_block_group_cache *cache;
cache = block_group_cache_tree_search(info, bytenr, 1);
return cache;
}
static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
u64 flags)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
flags &= BTRFS_BLOCK_GROUP_TYPE_MASK;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list) {
if (found->flags & flags) {
rcu_read_unlock();
return found;
}
}
rcu_read_unlock();
return NULL;
}
/*
* after adding space to the filesystem, we need to clear the full flags
* on all the space infos.
*/
void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list)
found->full = 0;
rcu_read_unlock();
}
/* simple helper to search for an existing data extent at a given offset */
int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len)
{
int ret;
struct btrfs_key key;
struct btrfs_path *path;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = start;
key.offset = len;
key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
0, 0);
btrfs_free_path(path);
return ret;
}
/*
* helper function to lookup reference count and flags of a tree block.
*
* the head node for delayed ref is used to store the sum of all the
* reference count modifications queued up in the rbtree. the head
* node may also store the extent flags to set. This way you can check
* to see what the reference count and extent flags would be if all of
* the delayed refs are not processed.
*/
int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 offset, int metadata, u64 *refs, u64 *flags)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
struct extent_buffer *leaf;
struct btrfs_key key;
u32 item_size;
u64 num_refs;
u64 extent_flags;
int ret;
/*
* If we don't have skinny metadata, don't bother doing anything
* different
*/
if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
offset = root->nodesize;
metadata = 0;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (!trans) {
path->skip_locking = 1;
path->search_commit_root = 1;
}
search_again:
key.objectid = bytenr;
key.offset = offset;
if (metadata)
key.type = BTRFS_METADATA_ITEM_KEY;
else
key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_search_slot(trans, root->fs_info->extent_root,
&key, path, 0, 0);
if (ret < 0)
goto out_free;
if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) {
if (path->slots[0]) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid == bytenr &&
key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == root->nodesize)
ret = 0;
}
}
if (ret == 0) {
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
if (item_size >= sizeof(*ei)) {
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
num_refs = btrfs_extent_refs(leaf, ei);
extent_flags = btrfs_extent_flags(leaf, ei);
} else {
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
struct btrfs_extent_item_v0 *ei0;
BUG_ON(item_size != sizeof(*ei0));
ei0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item_v0);
num_refs = btrfs_extent_refs_v0(leaf, ei0);
/* FIXME: this isn't correct for data */
extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
#else
BUG();
#endif
}
BUG_ON(num_refs == 0);
} else {
num_refs = 0;
extent_flags = 0;
ret = 0;
}
if (!trans)
goto out;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (head) {
if (!mutex_trylock(&head->mutex)) {
atomic_inc(&head->node.refs);
spin_unlock(&delayed_refs->lock);
btrfs_release_path(path);
/*
* Mutex was contended, block until it's released and try
* again
*/
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
goto search_again;
}
spin_lock(&head->lock);
if (head->extent_op && head->extent_op->update_flags)
extent_flags |= head->extent_op->flags_to_set;
else
BUG_ON(num_refs == 0);
num_refs += head->node.ref_mod;
spin_unlock(&head->lock);
mutex_unlock(&head->mutex);
}
spin_unlock(&delayed_refs->lock);
out:
WARN_ON(num_refs == 0);
if (refs)
*refs = num_refs;
if (flags)
*flags = extent_flags;
out_free:
btrfs_free_path(path);
return ret;
}
/*
* Back reference rules. Back refs have three main goals:
*
* 1) differentiate between all holders of references to an extent so that
* when a reference is dropped we can make sure it was a valid reference
* before freeing the extent.
*
* 2) Provide enough information to quickly find the holders of an extent
* if we notice a given block is corrupted or bad.
*
* 3) Make it easy to migrate blocks for FS shrinking or storage pool
* maintenance. This is actually the same as #2, but with a slightly
* different use case.
*
* There are two kinds of back refs. The implicit back refs is optimized
* for pointers in non-shared tree blocks. For a given pointer in a block,
* back refs of this kind provide information about the block's owner tree
* and the pointer's key. These information allow us to find the block by
* b-tree searching. The full back refs is for pointers in tree blocks not
* referenced by their owner trees. The location of tree block is recorded
* in the back refs. Actually the full back refs is generic, and can be
* used in all cases the implicit back refs is used. The major shortcoming
* of the full back refs is its overhead. Every time a tree block gets
* COWed, we have to update back refs entry for all pointers in it.
*
* For a newly allocated tree block, we use implicit back refs for
* pointers in it. This means most tree related operations only involve
* implicit back refs. For a tree block created in old transaction, the
* only way to drop a reference to it is COW it. So we can detect the
* event that tree block loses its owner tree's reference and do the
* back refs conversion.
*
* When a tree block is COW'd through a tree, there are four cases:
*
* The reference count of the block is one and the tree is the block's
* owner tree. Nothing to do in this case.
*
* The reference count of the block is one and the tree is not the
* block's owner tree. In this case, full back refs is used for pointers
* in the block. Remove these full back refs, add implicit back refs for
* every pointers in the new block.
*
* The reference count of the block is greater than one and the tree is
* the block's owner tree. In this case, implicit back refs is used for
* pointers in the block. Add full back refs for every pointers in the
* block, increase lower level extents' reference counts. The original
* implicit back refs are entailed to the new block.
*
* The reference count of the block is greater than one and the tree is
* not the block's owner tree. Add implicit back refs for every pointer in
* the new block, increase lower level extents' reference count.
*
* Back Reference Key composing:
*
* The key objectid corresponds to the first byte in the extent,
* The key type is used to differentiate between types of back refs.
* There are different meanings of the key offset for different types
* of back refs.
*
* File extents can be referenced by:
*
* - multiple snapshots, subvolumes, or different generations in one subvol
* - different files inside a single subvolume
* - different offsets inside a file (bookend extents in file.c)
*
* The extent ref structure for the implicit back refs has fields for:
*
* - Objectid of the subvolume root
* - objectid of the file holding the reference
* - original offset in the file
* - how many bookend extents
*
* The key offset for the implicit back refs is hash of the first
* three fields.
*
* The extent ref structure for the full back refs has field for:
*
* - number of pointers in the tree leaf
*
* The key offset for the implicit back refs is the first byte of
* the tree leaf
*
* When a file extent is allocated, The implicit back refs is used.
* the fields are filled in:
*
* (root_key.objectid, inode objectid, offset in file, 1)
*
* When a file extent is removed file truncation, we find the
* corresponding implicit back refs and check the following fields:
*
* (btrfs_header_owner(leaf), inode objectid, offset in file)
*
* Btree extents can be referenced by:
*
* - Different subvolumes
*
* Both the implicit back refs and the full back refs for tree blocks
* only consist of key. The key offset for the implicit back refs is
* objectid of block's owner tree. The key offset for the full back refs
* is the first byte of parent block.
*
* When implicit back refs is used, information about the lowest key and
* level of the tree block are required. These information are stored in
* tree block info structure.
*/
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
static int convert_extent_item_v0(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 owner, u32 extra_size)
{
struct btrfs_extent_item *item;
struct btrfs_extent_item_v0 *ei0;
struct btrfs_extent_ref_v0 *ref0;
struct btrfs_tree_block_info *bi;
struct extent_buffer *leaf;
struct btrfs_key key;
struct btrfs_key found_key;
u32 new_size = sizeof(*item);
u64 refs;
int ret;
leaf = path->nodes[0];
BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
ei0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item_v0);
refs = btrfs_extent_refs_v0(leaf, ei0);
if (owner == (u64)-1) {
while (1) {
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
BUG_ON(ret > 0); /* Corruption */
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0]);
BUG_ON(key.objectid != found_key.objectid);
if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {
path->slots[0]++;
continue;
}
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
owner = btrfs_ref_objectid_v0(leaf, ref0);
break;
}
}
btrfs_release_path(path);
if (owner < BTRFS_FIRST_FREE_OBJECTID)
new_size += sizeof(*bi);
new_size -= sizeof(*ei0);
ret = btrfs_search_slot(trans, root, &key, path,
new_size + extra_size, 1);
if (ret < 0)
return ret;
BUG_ON(ret); /* Corruption */
btrfs_extend_item(root, path, new_size);
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, item, refs);
/* FIXME: get real generation */
btrfs_set_extent_generation(leaf, item, 0);
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
btrfs_set_extent_flags(leaf, item,
BTRFS_EXTENT_FLAG_TREE_BLOCK |
BTRFS_BLOCK_FLAG_FULL_BACKREF);
bi = (struct btrfs_tree_block_info *)(item + 1);
/* FIXME: get first key of the block */
memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi));
btrfs_set_tree_block_level(leaf, bi, (int)owner);
} else {
btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);
}
btrfs_mark_buffer_dirty(leaf);
return 0;
}
#endif
static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
{
u32 high_crc = ~(u32)0;
u32 low_crc = ~(u32)0;
__le64 lenum;
lenum = cpu_to_le64(root_objectid);
high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(owner);
low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(offset);
low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
return ((u64)high_crc << 31) ^ (u64)low_crc;
}
static u64 hash_extent_data_ref_item(struct extent_buffer *leaf,
struct btrfs_extent_data_ref *ref)
{
return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref),
btrfs_extent_data_ref_objectid(leaf, ref),
btrfs_extent_data_ref_offset(leaf, ref));
}
static int match_extent_data_ref(struct extent_buffer *leaf,
struct btrfs_extent_data_ref *ref,
u64 root_objectid, u64 owner, u64 offset)
{
if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid ||
btrfs_extent_data_ref_objectid(leaf, ref) != owner ||
btrfs_extent_data_ref_offset(leaf, ref) != offset)
return 0;
return 1;
}
static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid,
u64 owner, u64 offset)
{
struct btrfs_key key;
struct btrfs_extent_data_ref *ref;
struct extent_buffer *leaf;
u32 nritems;
int ret;
int recow;
int err = -ENOENT;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_DATA_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_EXTENT_DATA_REF_KEY;
key.offset = hash_extent_data_ref(root_objectid,
owner, offset);
}
again:
recow = 0;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (parent) {
if (!ret)
return 0;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
key.type = BTRFS_EXTENT_REF_V0_KEY;
btrfs_release_path(path);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto fail;
}
if (!ret)
return 0;
#endif
goto fail;
}
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
while (1) {
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
err = ret;
if (ret)
goto fail;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
recow = 1;
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != bytenr ||
key.type != BTRFS_EXTENT_DATA_REF_KEY)
goto fail;
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (match_extent_data_ref(leaf, ref, root_objectid,
owner, offset)) {
if (recow) {
btrfs_release_path(path);
goto again;
}
err = 0;
break;
}
path->slots[0]++;
}
fail:
return err;
}
static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid, u64 owner,
u64 offset, int refs_to_add)
{
struct btrfs_key key;
struct extent_buffer *leaf;
u32 size;
u32 num_refs;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_DATA_REF_KEY;
key.offset = parent;
size = sizeof(struct btrfs_shared_data_ref);
} else {
key.type = BTRFS_EXTENT_DATA_REF_KEY;
key.offset = hash_extent_data_ref(root_objectid,
owner, offset);
size = sizeof(struct btrfs_extent_data_ref);
}
ret = btrfs_insert_empty_item(trans, root, path, &key, size);
if (ret && ret != -EEXIST)
goto fail;
leaf = path->nodes[0];
if (parent) {
struct btrfs_shared_data_ref *ref;
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
if (ret == 0) {
btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add);
} else {
num_refs = btrfs_shared_data_ref_count(leaf, ref);
num_refs += refs_to_add;
btrfs_set_shared_data_ref_count(leaf, ref, num_refs);
}
} else {
struct btrfs_extent_data_ref *ref;
while (ret == -EEXIST) {
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (match_extent_data_ref(leaf, ref, root_objectid,
owner, offset))
break;
btrfs_release_path(path);
key.offset++;
ret = btrfs_insert_empty_item(trans, root, path, &key,
size);
if (ret && ret != -EEXIST)
goto fail;
leaf = path->nodes[0];
}
ref = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
if (ret == 0) {
btrfs_set_extent_data_ref_root(leaf, ref,
root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
btrfs_set_extent_data_ref_offset(leaf, ref, offset);
btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add);
} else {
num_refs = btrfs_extent_data_ref_count(leaf, ref);
num_refs += refs_to_add;
btrfs_set_extent_data_ref_count(leaf, ref, num_refs);
}
}
btrfs_mark_buffer_dirty(leaf);
ret = 0;
fail:
btrfs_release_path(path);
return ret;
}
static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
int refs_to_drop, int *last_ref)
{
struct btrfs_key key;
struct btrfs_extent_data_ref *ref1 = NULL;
struct btrfs_shared_data_ref *ref2 = NULL;
struct extent_buffer *leaf;
u32 num_refs = 0;
int ret = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
ref2 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
} else {
BUG();
}
BUG_ON(num_refs < refs_to_drop);
num_refs -= refs_to_drop;
if (num_refs == 0) {
ret = btrfs_del_item(trans, root, path);
*last_ref = 1;
} else {
if (key.type == BTRFS_EXTENT_DATA_REF_KEY)
btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);
else if (key.type == BTRFS_SHARED_DATA_REF_KEY)
btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
else {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
btrfs_set_ref_count_v0(leaf, ref0, num_refs);
}
#endif
btrfs_mark_buffer_dirty(leaf);
}
return ret;
}
static noinline u32 extent_data_ref_count(struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_data_ref *ref1;
struct btrfs_shared_data_ref *ref2;
u32 num_refs = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (iref) {
if (btrfs_extent_inline_ref_type(leaf, iref) ==
BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = (struct btrfs_extent_data_ref *)(&iref->offset);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else {
ref2 = (struct btrfs_shared_data_ref *)(iref + 1);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
}
} else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
ref1 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_data_ref);
num_refs = btrfs_extent_data_ref_count(leaf, ref1);
} else if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
ref2 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_shared_data_ref);
num_refs = btrfs_shared_data_ref_count(leaf, ref2);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
struct btrfs_extent_ref_v0 *ref0;
ref0 = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_ref_v0);
num_refs = btrfs_ref_count_v0(leaf, ref0);
#endif
} else {
WARN_ON(1);
}
return num_refs;
}
static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid)
{
struct btrfs_key key;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_BLOCK_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_TREE_BLOCK_REF_KEY;
key.offset = root_objectid;
}
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (ret == -ENOENT && parent) {
btrfs_release_path(path);
key.type = BTRFS_EXTENT_REF_V0_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -ENOENT;
}
#endif
return ret;
}
static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent,
u64 root_objectid)
{
struct btrfs_key key;
int ret;
key.objectid = bytenr;
if (parent) {
key.type = BTRFS_SHARED_BLOCK_REF_KEY;
key.offset = parent;
} else {
key.type = BTRFS_TREE_BLOCK_REF_KEY;
key.offset = root_objectid;
}
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
btrfs_release_path(path);
return ret;
}
static inline int extent_ref_type(u64 parent, u64 owner)
{
int type;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
if (parent > 0)
type = BTRFS_SHARED_BLOCK_REF_KEY;
else
type = BTRFS_TREE_BLOCK_REF_KEY;
} else {
if (parent > 0)
type = BTRFS_SHARED_DATA_REF_KEY;
else
type = BTRFS_EXTENT_DATA_REF_KEY;
}
return type;
}
static int find_next_key(struct btrfs_path *path, int level,
struct btrfs_key *key)
{
for (; level < BTRFS_MAX_LEVEL; level++) {
if (!path->nodes[level])
break;
if (path->slots[level] + 1 >=
btrfs_header_nritems(path->nodes[level]))
continue;
if (level == 0)
btrfs_item_key_to_cpu(path->nodes[level], key,
path->slots[level] + 1);
else
btrfs_node_key_to_cpu(path->nodes[level], key,
path->slots[level] + 1);
return 0;
}
return 1;
}
/*
* look for inline back ref. if back ref is found, *ref_ret is set
* to the address of inline back ref, and 0 is returned.
*
* if back ref isn't found, *ref_ret is set to the address where it
* should be inserted, and -ENOENT is returned.
*
* if insert is true and there are too many inline back refs, the path
* points to the extent item, and -EAGAIN is returned.
*
* NOTE: inline back refs are ordered in the same way that back ref
* items in the tree are ordered.
*/
static noinline_for_stack
int lookup_inline_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref **ref_ret,
u64 bytenr, u64 num_bytes,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int insert)
{
struct btrfs_key key;
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
u64 flags;
u64 item_size;
unsigned long ptr;
unsigned long end;
int extra_size;
int type;
int want;
int ret;
int err = 0;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
want = extent_ref_type(parent, owner);
if (insert) {
extra_size = btrfs_extent_inline_ref_size(want);
path->keep_locks = 1;
} else
extra_size = -1;
/*
* Owner is our parent level, so we can just add one to get the level
* for the block we are interested in.
*/
if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) {
key.type = BTRFS_METADATA_ITEM_KEY;
key.offset = owner;
}
again:
ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1);
if (ret < 0) {
err = ret;
goto out;
}
/*
* We may be a newly converted file system which still has the old fat
* extent entries for metadata, so try and see if we have one of those.
*/
if (ret > 0 && skinny_metadata) {
skinny_metadata = false;
if (path->slots[0]) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid == bytenr &&
key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == num_bytes)
ret = 0;
}
if (ret) {
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
btrfs_release_path(path);
goto again;
}
}
if (ret && !insert) {
err = -ENOENT;
goto out;
} else if (WARN_ON(ret)) {
err = -EIO;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
if (!insert) {
err = -ENOENT;
goto out;
}
ret = convert_extent_item_v0(trans, root, path, owner,
extra_size);
if (ret < 0) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
flags = btrfs_extent_flags(leaf, ei);
ptr = (unsigned long)(ei + 1);
end = (unsigned long)ei + item_size;
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) {
ptr += sizeof(struct btrfs_tree_block_info);
BUG_ON(ptr > end);
}
err = -ENOENT;
while (1) {
if (ptr >= end) {
WARN_ON(ptr > end);
break;
}
iref = (struct btrfs_extent_inline_ref *)ptr;
type = btrfs_extent_inline_ref_type(leaf, iref);
if (want < type)
break;
if (want > type) {
ptr += btrfs_extent_inline_ref_size(type);
continue;
}
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
struct btrfs_extent_data_ref *dref;
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
if (match_extent_data_ref(leaf, dref, root_objectid,
owner, offset)) {
err = 0;
break;
}
if (hash_extent_data_ref_item(leaf, dref) <
hash_extent_data_ref(root_objectid, owner, offset))
break;
} else {
u64 ref_offset;
ref_offset = btrfs_extent_inline_ref_offset(leaf, iref);
if (parent > 0) {
if (parent == ref_offset) {
err = 0;
break;
}
if (ref_offset < parent)
break;
} else {
if (root_objectid == ref_offset) {
err = 0;
break;
}
if (ref_offset < root_objectid)
break;
}
}
ptr += btrfs_extent_inline_ref_size(type);
}
if (err == -ENOENT && insert) {
if (item_size + extra_size >=
BTRFS_MAX_EXTENT_ITEM_SIZE(root)) {
err = -EAGAIN;
goto out;
}
/*
* To add new inline back ref, we have to make sure
* there is no corresponding back ref item.
* For simplicity, we just do not add new inline back
* ref if there is any kind of item for this block
*/
if (find_next_key(path, 0, &key) == 0 &&
key.objectid == bytenr &&
key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) {
err = -EAGAIN;
goto out;
}
}
*ref_ret = (struct btrfs_extent_inline_ref *)ptr;
out:
if (insert) {
path->keep_locks = 0;
btrfs_unlock_up_safe(path, 1);
}
return err;
}
/*
* helper to add new inline back ref
*/
static noinline_for_stack
void setup_inline_extent_backref(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add,
struct btrfs_delayed_extent_op *extent_op)
{
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
unsigned long ptr;
unsigned long end;
unsigned long item_offset;
u64 refs;
int size;
int type;
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
item_offset = (unsigned long)iref - (unsigned long)ei;
type = extent_ref_type(parent, owner);
size = btrfs_extent_inline_ref_size(type);
btrfs_extend_item(root, path, size);
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
refs += refs_to_add;
btrfs_set_extent_refs(leaf, ei, refs);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
ptr = (unsigned long)ei + item_offset;
end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]);
if (ptr < end - size)
memmove_extent_buffer(leaf, ptr + size, ptr,
end - size - ptr);
iref = (struct btrfs_extent_inline_ref *)ptr;
btrfs_set_extent_inline_ref_type(leaf, iref, type);
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
struct btrfs_extent_data_ref *dref;
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
btrfs_set_extent_data_ref_root(leaf, dref, root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, dref, owner);
btrfs_set_extent_data_ref_offset(leaf, dref, offset);
btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add);
} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
struct btrfs_shared_data_ref *sref;
sref = (struct btrfs_shared_data_ref *)(iref + 1);
btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else if (type == BTRFS_SHARED_BLOCK_REF_KEY) {
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else {
btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
}
btrfs_mark_buffer_dirty(leaf);
}
static int lookup_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref **ref_ret,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner, u64 offset)
{
int ret;
ret = lookup_inline_extent_backref(trans, root, path, ref_ret,
bytenr, num_bytes, parent,
root_objectid, owner, offset, 0);
if (ret != -ENOENT)
return ret;
btrfs_release_path(path);
*ref_ret = NULL;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = lookup_tree_block_ref(trans, root, path, bytenr, parent,
root_objectid);
} else {
ret = lookup_extent_data_ref(trans, root, path, bytenr, parent,
root_objectid, owner, offset);
}
return ret;
}
/*
* helper to update/remove inline back ref
*/
static noinline_for_stack
void update_inline_extent_backref(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
int refs_to_mod,
struct btrfs_delayed_extent_op *extent_op,
int *last_ref)
{
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_data_ref *dref = NULL;
struct btrfs_shared_data_ref *sref = NULL;
unsigned long ptr;
unsigned long end;
u32 item_size;
int size;
int type;
u64 refs;
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, ei);
WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0);
refs += refs_to_mod;
btrfs_set_extent_refs(leaf, ei, refs);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
type = btrfs_extent_inline_ref_type(leaf, iref);
if (type == BTRFS_EXTENT_DATA_REF_KEY) {
dref = (struct btrfs_extent_data_ref *)(&iref->offset);
refs = btrfs_extent_data_ref_count(leaf, dref);
} else if (type == BTRFS_SHARED_DATA_REF_KEY) {
sref = (struct btrfs_shared_data_ref *)(iref + 1);
refs = btrfs_shared_data_ref_count(leaf, sref);
} else {
refs = 1;
BUG_ON(refs_to_mod != -1);
}
BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod);
refs += refs_to_mod;
if (refs > 0) {
if (type == BTRFS_EXTENT_DATA_REF_KEY)
btrfs_set_extent_data_ref_count(leaf, dref, refs);
else
btrfs_set_shared_data_ref_count(leaf, sref, refs);
} else {
*last_ref = 1;
size = btrfs_extent_inline_ref_size(type);
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
ptr = (unsigned long)iref;
end = (unsigned long)ei + item_size;
if (ptr + size < end)
memmove_extent_buffer(leaf, ptr, ptr + size,
end - ptr - size);
item_size -= size;
btrfs_truncate_item(root, path, item_size, 1);
}
btrfs_mark_buffer_dirty(leaf);
}
static noinline_for_stack
int insert_inline_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner,
u64 offset, int refs_to_add,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_extent_inline_ref *iref;
int ret;
ret = lookup_inline_extent_backref(trans, root, path, &iref,
bytenr, num_bytes, parent,
root_objectid, owner, offset, 1);
if (ret == 0) {
BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID);
update_inline_extent_backref(root, path, iref,
refs_to_add, extent_op, NULL);
} else if (ret == -ENOENT) {
setup_inline_extent_backref(root, path, iref, parent,
root_objectid, owner, offset,
refs_to_add, extent_op);
ret = 0;
}
return ret;
}
static int insert_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 bytenr, u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add)
{
int ret;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
BUG_ON(refs_to_add != 1);
ret = insert_tree_block_ref(trans, root, path, bytenr,
parent, root_objectid);
} else {
ret = insert_extent_data_ref(trans, root, path, bytenr,
parent, root_objectid,
owner, offset, refs_to_add);
}
return ret;
}
static int remove_extent_backref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_extent_inline_ref *iref,
int refs_to_drop, int is_data, int *last_ref)
{
int ret = 0;
BUG_ON(!is_data && refs_to_drop != 1);
if (iref) {
update_inline_extent_backref(root, path, iref,
-refs_to_drop, NULL, last_ref);
} else if (is_data) {
ret = remove_extent_data_ref(trans, root, path, refs_to_drop,
last_ref);
} else {
*last_ref = 1;
ret = btrfs_del_item(trans, root, path);
}
return ret;
}
#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len,
u64 *discarded_bytes)
{
int j, ret = 0;
u64 bytes_left, end;
u64 aligned_start = ALIGN(start, 1 << 9);
if (WARN_ON(start != aligned_start)) {
len -= aligned_start - start;
len = round_down(len, 1 << 9);
start = aligned_start;
}
*discarded_bytes = 0;
if (!len)
return 0;
end = start + len;
bytes_left = len;
/* Skip any superblocks on this device. */
for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) {
u64 sb_start = btrfs_sb_offset(j);
u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE;
u64 size = sb_start - start;
if (!in_range(sb_start, start, bytes_left) &&
!in_range(sb_end, start, bytes_left) &&
!in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE))
continue;
/*
* Superblock spans beginning of range. Adjust start and
* try again.
*/
if (sb_start <= start) {
start += sb_end - start;
if (start > end) {
bytes_left = 0;
break;
}
bytes_left = end - start;
continue;
}
if (size) {
ret = blkdev_issue_discard(bdev, start >> 9, size >> 9,
GFP_NOFS, 0);
if (!ret)
*discarded_bytes += size;
else if (ret != -EOPNOTSUPP)
return ret;
}
start = sb_end;
if (start > end) {
bytes_left = 0;
break;
}
bytes_left = end - start;
}
if (bytes_left) {
ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9,
GFP_NOFS, 0);
if (!ret)
*discarded_bytes += bytes_left;
}
return ret;
}
int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
u64 num_bytes, u64 *actual_bytes)
{
int ret;
u64 discarded_bytes = 0;
struct btrfs_bio *bbio = NULL;
/* Tell the block device(s) that the sectors can be discarded */
ret = btrfs_map_block(root->fs_info, REQ_DISCARD,
bytenr, &num_bytes, &bbio, 0);
/* Error condition is -ENOMEM */
if (!ret) {
struct btrfs_bio_stripe *stripe = bbio->stripes;
int i;
for (i = 0; i < bbio->num_stripes; i++, stripe++) {
u64 bytes;
if (!stripe->dev->can_discard)
continue;
ret = btrfs_issue_discard(stripe->dev->bdev,
stripe->physical,
stripe->length,
&bytes);
if (!ret)
discarded_bytes += bytes;
else if (ret != -EOPNOTSUPP)
break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */
/*
* Just in case we get back EOPNOTSUPP for some reason,
* just ignore the return value so we don't screw up
* people calling discard_extent.
*/
ret = 0;
}
btrfs_put_bbio(bbio);
}
if (actual_bytes)
*actual_bytes = discarded_bytes;
if (ret == -EOPNOTSUPP)
ret = 0;
return ret;
}
/* Can return -ENOMEM */
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent,
u64 root_objectid, u64 owner, u64 offset,
int no_quota)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID &&
root_objectid == BTRFS_TREE_LOG_OBJECTID);
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
num_bytes,
parent, root_objectid, (int)owner,
BTRFS_ADD_DELAYED_REF, NULL, no_quota);
} else {
ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
num_bytes,
parent, root_objectid, owner, offset,
BTRFS_ADD_DELAYED_REF, NULL, no_quota);
}
return ret;
}
static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
u64 parent, u64 root_objectid,
u64 owner, u64 offset, int refs_to_add,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_extent_item *item;
struct btrfs_key key;
u64 bytenr = node->bytenr;
u64 num_bytes = node->num_bytes;
u64 refs;
int ret;
int no_quota = node->no_quota;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (!is_fstree(root_objectid) || !root->fs_info->quota_enabled)
no_quota = 1;
path->reada = 1;
path->leave_spinning = 1;
/* this will setup the path even if it fails to insert the back ref */
ret = insert_inline_extent_backref(trans, fs_info->extent_root, path,
bytenr, num_bytes, parent,
root_objectid, owner, offset,
refs_to_add, extent_op);
if ((ret < 0 && ret != -EAGAIN) || !ret)
goto out;
/*
* Ok we had -EAGAIN which means we didn't have space to insert and
* inline extent ref, so just update the reference count and add a
* normal backref.
*/
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
refs = btrfs_extent_refs(leaf, item);
btrfs_set_extent_refs(leaf, item, refs + refs_to_add);
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, item);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
path->reada = 1;
path->leave_spinning = 1;
/* now insert the actual backref */
ret = insert_extent_backref(trans, root->fs_info->extent_root,
path, bytenr, parent, root_objectid,
owner, offset, refs_to_add);
if (ret)
btrfs_abort_transaction(trans, root, ret);
out:
btrfs_free_path(path);
return ret;
}
static int run_delayed_data_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret = 0;
struct btrfs_delayed_data_ref *ref;
struct btrfs_key ins;
u64 parent = 0;
u64 ref_root = 0;
u64 flags = 0;
ins.objectid = node->bytenr;
ins.offset = node->num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ref = btrfs_delayed_node_to_data_ref(node);
trace_run_delayed_data_ref(node, ref, node->action);
if (node->type == BTRFS_SHARED_DATA_REF_KEY)
parent = ref->parent;
ref_root = ref->root;
if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
if (extent_op)
flags |= extent_op->flags_to_set;
ret = alloc_reserved_file_extent(trans, root,
parent, ref_root, flags,
ref->objectid, ref->offset,
&ins, node->ref_mod);
} else if (node->action == BTRFS_ADD_DELAYED_REF) {
ret = __btrfs_inc_extent_ref(trans, root, node, parent,
ref_root, ref->objectid,
ref->offset, node->ref_mod,
extent_op);
} else if (node->action == BTRFS_DROP_DELAYED_REF) {
ret = __btrfs_free_extent(trans, root, node, parent,
ref_root, ref->objectid,
ref->offset, node->ref_mod,
extent_op);
} else {
BUG();
}
return ret;
}
static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op,
struct extent_buffer *leaf,
struct btrfs_extent_item *ei)
{
u64 flags = btrfs_extent_flags(leaf, ei);
if (extent_op->update_flags) {
flags |= extent_op->flags_to_set;
btrfs_set_extent_flags(leaf, ei, flags);
}
if (extent_op->update_key) {
struct btrfs_tree_block_info *bi;
BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK));
bi = (struct btrfs_tree_block_info *)(ei + 1);
btrfs_set_tree_block_key(leaf, bi, &extent_op->key);
}
}
static int run_delayed_extent_op(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_key key;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
struct extent_buffer *leaf;
u32 item_size;
int ret;
int err = 0;
int metadata = !extent_op->is_data;
if (trans->aborted)
return 0;
if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
metadata = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = node->bytenr;
if (metadata) {
key.type = BTRFS_METADATA_ITEM_KEY;
key.offset = extent_op->level;
} else {
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = node->num_bytes;
}
again:
path->reada = 1;
path->leave_spinning = 1;
ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key,
path, 0, 1);
if (ret < 0) {
err = ret;
goto out;
}
if (ret > 0) {
if (metadata) {
if (path->slots[0] > 0) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid == node->bytenr &&
key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == node->num_bytes)
ret = 0;
}
if (ret > 0) {
btrfs_release_path(path);
metadata = 0;
key.objectid = node->bytenr;
key.offset = node->num_bytes;
key.type = BTRFS_EXTENT_ITEM_KEY;
goto again;
}
} else {
err = -EIO;
goto out;
}
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
ret = convert_extent_item_v0(trans, root->fs_info->extent_root,
path, (u64)-1, 0);
if (ret < 0) {
err = ret;
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
__run_delayed_extent_op(extent_op, leaf, ei);
btrfs_mark_buffer_dirty(leaf);
out:
btrfs_free_path(path);
return err;
}
static int run_delayed_tree_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret = 0;
struct btrfs_delayed_tree_ref *ref;
struct btrfs_key ins;
u64 parent = 0;
u64 ref_root = 0;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
ref = btrfs_delayed_node_to_tree_ref(node);
trace_run_delayed_tree_ref(node, ref, node->action);
if (node->type == BTRFS_SHARED_BLOCK_REF_KEY)
parent = ref->parent;
ref_root = ref->root;
ins.objectid = node->bytenr;
if (skinny_metadata) {
ins.offset = ref->level;
ins.type = BTRFS_METADATA_ITEM_KEY;
} else {
ins.offset = node->num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
}
BUG_ON(node->ref_mod != 1);
if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) {
BUG_ON(!extent_op || !extent_op->update_flags);
ret = alloc_reserved_tree_block(trans, root,
parent, ref_root,
extent_op->flags_to_set,
&extent_op->key,
ref->level, &ins,
node->no_quota);
} else if (node->action == BTRFS_ADD_DELAYED_REF) {
ret = __btrfs_inc_extent_ref(trans, root, node,
parent, ref_root,
ref->level, 0, 1,
extent_op);
} else if (node->action == BTRFS_DROP_DELAYED_REF) {
ret = __btrfs_free_extent(trans, root, node,
parent, ref_root,
ref->level, 0, 1, extent_op);
} else {
BUG();
}
return ret;
}
/* helper function to actually process a single delayed ref entry */
static int run_one_delayed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node,
struct btrfs_delayed_extent_op *extent_op,
int insert_reserved)
{
int ret = 0;
if (trans->aborted) {
if (insert_reserved)
btrfs_pin_extent(root, node->bytenr,
node->num_bytes, 1);
return 0;
}
if (btrfs_delayed_ref_is_head(node)) {
struct btrfs_delayed_ref_head *head;
/*
* we've hit the end of the chain and we were supposed
* to insert this extent into the tree. But, it got
* deleted before we ever needed to insert it, so all
* we have to do is clean up the accounting
*/
BUG_ON(extent_op);
head = btrfs_delayed_node_to_head(node);
trace_run_delayed_ref_head(node, head, node->action);
if (insert_reserved) {
btrfs_pin_extent(root, node->bytenr,
node->num_bytes, 1);
if (head->is_data) {
ret = btrfs_del_csums(trans, root,
node->bytenr,
node->num_bytes);
}
}
return ret;
}
if (node->type == BTRFS_TREE_BLOCK_REF_KEY ||
node->type == BTRFS_SHARED_BLOCK_REF_KEY)
ret = run_delayed_tree_ref(trans, root, node, extent_op,
insert_reserved);
else if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||
node->type == BTRFS_SHARED_DATA_REF_KEY)
ret = run_delayed_data_ref(trans, root, node, extent_op,
insert_reserved);
else
BUG();
return ret;
}
static inline struct btrfs_delayed_ref_node *
select_delayed_ref(struct btrfs_delayed_ref_head *head)
{
struct btrfs_delayed_ref_node *ref;
if (list_empty(&head->ref_list))
return NULL;
/*
* Select a delayed ref of type BTRFS_ADD_DELAYED_REF first.
* This is to prevent a ref count from going down to zero, which deletes
* the extent item from the extent tree, when there still are references
* to add, which would fail because they would not find the extent item.
*/
list_for_each_entry(ref, &head->ref_list, list) {
if (ref->action == BTRFS_ADD_DELAYED_REF)
return ref;
}
return list_entry(head->ref_list.next, struct btrfs_delayed_ref_node,
list);
}
/*
* Returns 0 on success or if called with an already aborted transaction.
* Returns -ENOMEM or -EIO on failure and will abort the transaction.
*/
static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
unsigned long nr)
{
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_delayed_ref_node *ref;
struct btrfs_delayed_ref_head *locked_ref = NULL;
struct btrfs_delayed_extent_op *extent_op;
struct btrfs_fs_info *fs_info = root->fs_info;
ktime_t start = ktime_get();
int ret;
unsigned long count = 0;
unsigned long actual_count = 0;
int must_insert_reserved = 0;
delayed_refs = &trans->transaction->delayed_refs;
while (1) {
if (!locked_ref) {
if (count >= nr)
break;
spin_lock(&delayed_refs->lock);
locked_ref = btrfs_select_ref_head(trans);
if (!locked_ref) {
spin_unlock(&delayed_refs->lock);
break;
}
/* grab the lock that says we are going to process
* all the refs for this head */
ret = btrfs_delayed_ref_lock(trans, locked_ref);
spin_unlock(&delayed_refs->lock);
/*
* we may have dropped the spin lock to get the head
* mutex lock, and that might have given someone else
* time to free the head. If that's true, it has been
* removed from our list and we can move on.
*/
if (ret == -EAGAIN) {
locked_ref = NULL;
count++;
continue;
}
}
spin_lock(&locked_ref->lock);
/*
* locked_ref is the head node, so we have to go one
* node back for any delayed ref updates
*/
ref = select_delayed_ref(locked_ref);
if (ref && ref->seq &&
btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) {
spin_unlock(&locked_ref->lock);
btrfs_delayed_ref_unlock(locked_ref);
spin_lock(&delayed_refs->lock);
locked_ref->processing = 0;
delayed_refs->num_heads_ready++;
spin_unlock(&delayed_refs->lock);
locked_ref = NULL;
cond_resched();
count++;
continue;
}
/*
* record the must insert reserved flag before we
* drop the spin lock.
*/
must_insert_reserved = locked_ref->must_insert_reserved;
locked_ref->must_insert_reserved = 0;
extent_op = locked_ref->extent_op;
locked_ref->extent_op = NULL;
if (!ref) {
/* All delayed refs have been processed, Go ahead
* and send the head node to run_one_delayed_ref,
* so that any accounting fixes can happen
*/
ref = &locked_ref->node;
if (extent_op && must_insert_reserved) {
btrfs_free_delayed_extent_op(extent_op);
extent_op = NULL;
}
if (extent_op) {
spin_unlock(&locked_ref->lock);
ret = run_delayed_extent_op(trans, root,
ref, extent_op);
btrfs_free_delayed_extent_op(extent_op);
if (ret) {
/*
* Need to reset must_insert_reserved if
* there was an error so the abort stuff
* can cleanup the reserved space
* properly.
*/
if (must_insert_reserved)
locked_ref->must_insert_reserved = 1;
locked_ref->processing = 0;
btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret);
btrfs_delayed_ref_unlock(locked_ref);
return ret;
}
continue;
}
/*
* Need to drop our head ref lock and re-aqcuire the
* delayed ref lock and then re-check to make sure
* nobody got added.
*/
spin_unlock(&locked_ref->lock);
spin_lock(&delayed_refs->lock);
spin_lock(&locked_ref->lock);
if (!list_empty(&locked_ref->ref_list) ||
locked_ref->extent_op) {
spin_unlock(&locked_ref->lock);
spin_unlock(&delayed_refs->lock);
continue;
}
ref->in_tree = 0;
delayed_refs->num_heads--;
rb_erase(&locked_ref->href_node,
&delayed_refs->href_root);
spin_unlock(&delayed_refs->lock);
} else {
actual_count++;
ref->in_tree = 0;
list_del(&ref->list);
}
atomic_dec(&delayed_refs->num_entries);
if (!btrfs_delayed_ref_is_head(ref)) {
/*
* when we play the delayed ref, also correct the
* ref_mod on head
*/
switch (ref->action) {
case BTRFS_ADD_DELAYED_REF:
case BTRFS_ADD_DELAYED_EXTENT:
locked_ref->node.ref_mod -= ref->ref_mod;
break;
case BTRFS_DROP_DELAYED_REF:
locked_ref->node.ref_mod += ref->ref_mod;
break;
default:
WARN_ON(1);
}
}
spin_unlock(&locked_ref->lock);
ret = run_one_delayed_ref(trans, root, ref, extent_op,
must_insert_reserved);
btrfs_free_delayed_extent_op(extent_op);
if (ret) {
locked_ref->processing = 0;
btrfs_delayed_ref_unlock(locked_ref);
btrfs_put_delayed_ref(ref);
btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret);
return ret;
}
/*
* If this node is a head, that means all the refs in this head
* have been dealt with, and we will pick the next head to deal
* with, so we must unlock the head and drop it from the cluster
* list before we release it.
*/
if (btrfs_delayed_ref_is_head(ref)) {
if (locked_ref->is_data &&
locked_ref->total_ref_mod < 0) {
spin_lock(&delayed_refs->lock);
delayed_refs->pending_csums -= ref->num_bytes;
spin_unlock(&delayed_refs->lock);
}
btrfs_delayed_ref_unlock(locked_ref);
locked_ref = NULL;
}
btrfs_put_delayed_ref(ref);
count++;
cond_resched();
}
/*
* We don't want to include ref heads since we can have empty ref heads
* and those will drastically skew our runtime down since we just do
* accounting, no actual extent tree updates.
*/
if (actual_count > 0) {
u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start));
u64 avg;
/*
* We weigh the current average higher than our current runtime
* to avoid large swings in the average.
*/
spin_lock(&delayed_refs->lock);
avg = fs_info->avg_delayed_ref_runtime * 3 + runtime;
fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */
spin_unlock(&delayed_refs->lock);
}
return 0;
}
#ifdef SCRAMBLE_DELAYED_REFS
/*
* Normally delayed refs get processed in ascending bytenr order. This
* correlates in most cases to the order added. To expose dependencies on this
* order, we start to process the tree in the middle instead of the beginning
*/
static u64 find_middle(struct rb_root *root)
{
struct rb_node *n = root->rb_node;
struct btrfs_delayed_ref_node *entry;
int alt = 1;
u64 middle;
u64 first = 0, last = 0;
n = rb_first(root);
if (n) {
entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
first = entry->bytenr;
}
n = rb_last(root);
if (n) {
entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
last = entry->bytenr;
}
n = root->rb_node;
while (n) {
entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
WARN_ON(!entry->in_tree);
middle = entry->bytenr;
if (alt)
n = n->rb_left;
else
n = n->rb_right;
alt = 1 - alt;
}
return middle;
}
#endif
static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads)
{
u64 num_bytes;
num_bytes = heads * (sizeof(struct btrfs_extent_item) +
sizeof(struct btrfs_extent_inline_ref));
if (!btrfs_fs_incompat(root->fs_info, SKINNY_METADATA))
num_bytes += heads * sizeof(struct btrfs_tree_block_info);
/*
* We don't ever fill up leaves all the way so multiply by 2 just to be
* closer to what we're really going to want to ouse.
*/
return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root));
}
/*
* Takes the number of bytes to be csumm'ed and figures out how many leaves it
* would require to store the csums for that many bytes.
*/
u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes)
{
u64 csum_size;
u64 num_csums_per_leaf;
u64 num_csums;
csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item);
num_csums_per_leaf = div64_u64(csum_size,
(u64)btrfs_super_csum_size(root->fs_info->super_copy));
num_csums = div64_u64(csum_bytes, root->sectorsize);
num_csums += num_csums_per_leaf - 1;
num_csums = div64_u64(num_csums, num_csums_per_leaf);
return num_csums;
}
int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_rsv *global_rsv;
u64 num_heads = trans->transaction->delayed_refs.num_heads_ready;
u64 csum_bytes = trans->transaction->delayed_refs.pending_csums;
u64 num_dirty_bgs = trans->transaction->num_dirty_bgs;
u64 num_bytes, num_dirty_bgs_bytes;
int ret = 0;
num_bytes = btrfs_calc_trans_metadata_size(root, 1);
num_heads = heads_to_leaves(root, num_heads);
if (num_heads > 1)
num_bytes += (num_heads - 1) * root->nodesize;
num_bytes <<= 1;
num_bytes += btrfs_csum_bytes_to_leaves(root, csum_bytes) * root->nodesize;
num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(root,
num_dirty_bgs);
global_rsv = &root->fs_info->global_block_rsv;
/*
* If we can't allocate any more chunks lets make sure we have _lots_ of
* wiggle room since running delayed refs can create more delayed refs.
*/
if (global_rsv->space_info->full) {
num_dirty_bgs_bytes <<= 1;
num_bytes <<= 1;
}
spin_lock(&global_rsv->lock);
if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes)
ret = 1;
spin_unlock(&global_rsv->lock);
return ret;
}
int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
u64 num_entries =
atomic_read(&trans->transaction->delayed_refs.num_entries);
u64 avg_runtime;
u64 val;
smp_mb();
avg_runtime = fs_info->avg_delayed_ref_runtime;
val = num_entries * avg_runtime;
if (num_entries * avg_runtime >= NSEC_PER_SEC)
return 1;
if (val >= NSEC_PER_SEC / 2)
return 2;
return btrfs_check_space_for_delayed_refs(trans, root);
}
struct async_delayed_refs {
struct btrfs_root *root;
int count;
int error;
int sync;
struct completion wait;
struct btrfs_work work;
};
static void delayed_ref_async_start(struct btrfs_work *work)
{
struct async_delayed_refs *async;
struct btrfs_trans_handle *trans;
int ret;
async = container_of(work, struct async_delayed_refs, work);
trans = btrfs_join_transaction(async->root);
if (IS_ERR(trans)) {
async->error = PTR_ERR(trans);
goto done;
}
/*
* trans->sync means that when we call end_transaciton, we won't
* wait on delayed refs
*/
trans->sync = true;
ret = btrfs_run_delayed_refs(trans, async->root, async->count);
if (ret)
async->error = ret;
ret = btrfs_end_transaction(trans, async->root);
if (ret && !async->error)
async->error = ret;
done:
if (async->sync)
complete(&async->wait);
else
kfree(async);
}
int btrfs_async_run_delayed_refs(struct btrfs_root *root,
unsigned long count, int wait)
{
struct async_delayed_refs *async;
int ret;
async = kmalloc(sizeof(*async), GFP_NOFS);
if (!async)
return -ENOMEM;
async->root = root->fs_info->tree_root;
async->count = count;
async->error = 0;
if (wait)
async->sync = 1;
else
async->sync = 0;
init_completion(&async->wait);
btrfs_init_work(&async->work, btrfs_extent_refs_helper,
delayed_ref_async_start, NULL, NULL);
btrfs_queue_work(root->fs_info->extent_workers, &async->work);
if (wait) {
wait_for_completion(&async->wait);
ret = async->error;
kfree(async);
return ret;
}
return 0;
}
/*
* this starts processing the delayed reference count updates and
* extent insertions we have queued up so far. count can be
* 0, which means to process everything in the tree at the start
* of the run (but not newly added entries), or it can be some target
* number you'd like to process.
*
* Returns 0 on success or if called with an aborted transaction
* Returns <0 on error and aborts the transaction
*/
int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root, unsigned long count)
{
struct rb_node *node;
struct btrfs_delayed_ref_root *delayed_refs;
struct btrfs_delayed_ref_head *head;
int ret;
int run_all = count == (unsigned long)-1;
/* We'll clean this up in btrfs_cleanup_transaction */
if (trans->aborted)
return 0;
if (root == root->fs_info->extent_root)
root = root->fs_info->tree_root;
delayed_refs = &trans->transaction->delayed_refs;
if (count == 0)
count = atomic_read(&delayed_refs->num_entries) * 2;
again:
#ifdef SCRAMBLE_DELAYED_REFS
delayed_refs->run_delayed_start = find_middle(&delayed_refs->root);
#endif
ret = __btrfs_run_delayed_refs(trans, root, count);
if (ret < 0) {
btrfs_abort_transaction(trans, root, ret);
return ret;
}
if (run_all) {
if (!list_empty(&trans->new_bgs))
btrfs_create_pending_block_groups(trans, root);
spin_lock(&delayed_refs->lock);
node = rb_first(&delayed_refs->href_root);
if (!node) {
spin_unlock(&delayed_refs->lock);
goto out;
}
count = (unsigned long)-1;
while (node) {
head = rb_entry(node, struct btrfs_delayed_ref_head,
href_node);
if (btrfs_delayed_ref_is_head(&head->node)) {
struct btrfs_delayed_ref_node *ref;
ref = &head->node;
atomic_inc(&ref->refs);
spin_unlock(&delayed_refs->lock);
/*
* Mutex was contended, block until it's
* released and try again
*/
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(ref);
cond_resched();
goto again;
} else {
WARN_ON(1);
}
node = rb_next(node);
}
spin_unlock(&delayed_refs->lock);
cond_resched();
goto again;
}
out:
assert_qgroups_uptodate(trans);
return 0;
}
int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 flags,
int level, int is_data)
{
struct btrfs_delayed_extent_op *extent_op;
int ret;
extent_op = btrfs_alloc_delayed_extent_op();
if (!extent_op)
return -ENOMEM;
extent_op->flags_to_set = flags;
extent_op->update_flags = 1;
extent_op->update_key = 0;
extent_op->is_data = is_data ? 1 : 0;
extent_op->level = level;
ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr,
num_bytes, extent_op);
if (ret)
btrfs_free_delayed_extent_op(extent_op);
return ret;
}
static noinline int check_delayed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_node *ref;
struct btrfs_delayed_data_ref *data_ref;
struct btrfs_delayed_ref_root *delayed_refs;
int ret = 0;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (!head) {
spin_unlock(&delayed_refs->lock);
return 0;
}
if (!mutex_trylock(&head->mutex)) {
atomic_inc(&head->node.refs);
spin_unlock(&delayed_refs->lock);
btrfs_release_path(path);
/*
* Mutex was contended, block until it's released and let
* caller try again
*/
mutex_lock(&head->mutex);
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
return -EAGAIN;
}
spin_unlock(&delayed_refs->lock);
spin_lock(&head->lock);
list_for_each_entry(ref, &head->ref_list, list) {
/* If it's a shared ref we know a cross reference exists */
if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) {
ret = 1;
break;
}
data_ref = btrfs_delayed_node_to_data_ref(ref);
/*
* If our ref doesn't match the one we're currently looking at
* then we have a cross reference.
*/
if (data_ref->root != root->root_key.objectid ||
data_ref->objectid != objectid ||
data_ref->offset != offset) {
ret = 1;
break;
}
}
spin_unlock(&head->lock);
mutex_unlock(&head->mutex);
return ret;
}
static noinline int check_committed_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct extent_buffer *leaf;
struct btrfs_extent_data_ref *ref;
struct btrfs_extent_inline_ref *iref;
struct btrfs_extent_item *ei;
struct btrfs_key key;
u32 item_size;
int ret;
key.objectid = bytenr;
key.offset = (u64)-1;
key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0); /* Corruption */
ret = -ENOENT;
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY)
goto out;
ret = 1;
item_size = btrfs_item_size_nr(leaf, path->slots[0]);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
goto out;
}
#endif
ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
if (item_size != sizeof(*ei) +
btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
goto out;
if (btrfs_extent_generation(leaf, ei) <=
btrfs_root_last_snapshot(&root->root_item))
goto out;
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
if (btrfs_extent_inline_ref_type(leaf, iref) !=
BTRFS_EXTENT_DATA_REF_KEY)
goto out;
ref = (struct btrfs_extent_data_ref *)(&iref->offset);
if (btrfs_extent_refs(leaf, ei) !=
btrfs_extent_data_ref_count(leaf, ref) ||
btrfs_extent_data_ref_root(leaf, ref) !=
root->root_key.objectid ||
btrfs_extent_data_ref_objectid(leaf, ref) != objectid ||
btrfs_extent_data_ref_offset(leaf, ref) != offset)
goto out;
ret = 0;
out:
return ret;
}
int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 objectid, u64 offset, u64 bytenr)
{
struct btrfs_path *path;
int ret;
int ret2;
path = btrfs_alloc_path();
if (!path)
return -ENOENT;
do {
ret = check_committed_ref(trans, root, path, objectid,
offset, bytenr);
if (ret && ret != -ENOENT)
goto out;
ret2 = check_delayed_ref(trans, root, path, objectid,
offset, bytenr);
} while (ret2 == -EAGAIN);
if (ret2 && ret2 != -ENOENT) {
ret = ret2;
goto out;
}
if (ret != -ENOENT || ret2 != -ENOENT)
ret = 0;
out:
btrfs_free_path(path);
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
WARN_ON(ret > 0);
return ret;
}
static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
int full_backref, int inc)
{
u64 bytenr;
u64 num_bytes;
u64 parent;
u64 ref_root;
u32 nritems;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
int i;
int level;
int ret = 0;
int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *,
u64, u64, u64, u64, u64, u64, int);
if (btrfs_test_is_dummy_root(root))
return 0;
ref_root = btrfs_header_owner(buf);
nritems = btrfs_header_nritems(buf);
level = btrfs_header_level(buf);
if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0)
return 0;
if (inc)
process_func = btrfs_inc_extent_ref;
else
process_func = btrfs_free_extent;
if (full_backref)
parent = buf->start;
else
parent = 0;
for (i = 0; i < nritems; i++) {
if (level == 0) {
btrfs_item_key_to_cpu(buf, &key, i);
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(buf, i,
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(buf, fi) ==
BTRFS_FILE_EXTENT_INLINE)
continue;
bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
if (bytenr == 0)
continue;
num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi);
key.offset -= btrfs_file_extent_offset(buf, fi);
ret = process_func(trans, root, bytenr, num_bytes,
parent, ref_root, key.objectid,
key.offset, 1);
if (ret)
goto fail;
} else {
bytenr = btrfs_node_blockptr(buf, i);
num_bytes = root->nodesize;
ret = process_func(trans, root, bytenr, num_bytes,
parent, ref_root, level - 1, 0,
1);
if (ret)
goto fail;
}
}
return 0;
fail:
return ret;
}
int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, int full_backref)
{
return __btrfs_mod_ref(trans, root, buf, full_backref, 1);
}
int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *buf, int full_backref)
{
return __btrfs_mod_ref(trans, root, buf, full_backref, 0);
}
static int write_one_cache_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_block_group_cache *cache)
{
int ret;
struct btrfs_root *extent_root = root->fs_info->extent_root;
unsigned long bi;
struct extent_buffer *leaf;
ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto fail;
}
leaf = path->nodes[0];
bi = btrfs_item_ptr_offset(leaf, path->slots[0]);
write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item));
btrfs_mark_buffer_dirty(leaf);
fail:
btrfs_release_path(path);
return ret;
}
static struct btrfs_block_group_cache *
next_block_group(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct rb_node *node;
spin_lock(&root->fs_info->block_group_cache_lock);
/* If our block group was removed, we need a full search. */
if (RB_EMPTY_NODE(&cache->cache_node)) {
const u64 next_bytenr = cache->key.objectid + cache->key.offset;
spin_unlock(&root->fs_info->block_group_cache_lock);
btrfs_put_block_group(cache);
cache = btrfs_lookup_first_block_group(root->fs_info,
next_bytenr);
return cache;
}
node = rb_next(&cache->cache_node);
btrfs_put_block_group(cache);
if (node) {
cache = rb_entry(node, struct btrfs_block_group_cache,
cache_node);
btrfs_get_block_group(cache);
} else
cache = NULL;
spin_unlock(&root->fs_info->block_group_cache_lock);
return cache;
}
static int cache_save_setup(struct btrfs_block_group_cache *block_group,
struct btrfs_trans_handle *trans,
struct btrfs_path *path)
{
struct btrfs_root *root = block_group->fs_info->tree_root;
struct inode *inode = NULL;
u64 alloc_hint = 0;
int dcs = BTRFS_DC_ERROR;
u64 num_pages = 0;
int retries = 0;
int ret = 0;
/*
* If this block group is smaller than 100 megs don't bother caching the
* block group.
*/
if (block_group->key.offset < (100 * 1024 * 1024)) {
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_WRITTEN;
spin_unlock(&block_group->lock);
return 0;
}
if (trans->aborted)
return 0;
again:
inode = lookup_free_space_inode(root, block_group, path);
if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
ret = PTR_ERR(inode);
btrfs_release_path(path);
goto out;
}
if (IS_ERR(inode)) {
BUG_ON(retries);
retries++;
if (block_group->ro)
goto out_free;
ret = create_free_space_inode(root, trans, block_group, path);
if (ret)
goto out_free;
goto again;
}
/* We've already setup this transaction, go ahead and exit */
if (block_group->cache_generation == trans->transid &&
i_size_read(inode)) {
dcs = BTRFS_DC_SETUP;
goto out_put;
}
/*
* We want to set the generation to 0, that way if anything goes wrong
* from here on out we know not to trust this cache when we load up next
* time.
*/
BTRFS_I(inode)->generation = 0;
ret = btrfs_update_inode(trans, root, inode);
if (ret) {
/*
* So theoretically we could recover from this, simply set the
* super cache generation to 0 so we know to invalidate the
* cache, but then we'd have to keep track of the block groups
* that fail this way so we know we _have_ to reset this cache
* before the next commit or risk reading stale cache. So to
* limit our exposure to horrible edge cases lets just abort the
* transaction, this only happens in really bad situations
* anyway.
*/
btrfs_abort_transaction(trans, root, ret);
goto out_put;
}
WARN_ON(ret);
if (i_size_read(inode) > 0) {
ret = btrfs_check_trunc_cache_free_space(root,
&root->fs_info->global_block_rsv);
if (ret)
goto out_put;
ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode);
if (ret)
goto out_put;
}
spin_lock(&block_group->lock);
if (block_group->cached != BTRFS_CACHE_FINISHED ||
!btrfs_test_opt(root, SPACE_CACHE)) {
/*
* don't bother trying to write stuff out _if_
* a) we're not cached,
* b) we're with nospace_cache mount option.
*/
dcs = BTRFS_DC_WRITTEN;
spin_unlock(&block_group->lock);
goto out_put;
}
spin_unlock(&block_group->lock);
/*
* Try to preallocate enough space based on how big the block group is.
* Keep in mind this has to include any pinned space which could end up
* taking up quite a bit since it's not folded into the other space
* cache.
*/
num_pages = div_u64(block_group->key.offset, 256 * 1024 * 1024);
if (!num_pages)
num_pages = 1;
num_pages *= 16;
num_pages *= PAGE_CACHE_SIZE;
ret = btrfs_check_data_free_space(inode, num_pages, num_pages);
if (ret)
goto out_put;
ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
num_pages, num_pages,
&alloc_hint);
if (!ret)
dcs = BTRFS_DC_SETUP;
btrfs_free_reserved_data_space(inode, num_pages);
out_put:
iput(inode);
out_free:
btrfs_release_path(path);
out:
spin_lock(&block_group->lock);
if (!ret && dcs == BTRFS_DC_SETUP)
block_group->cache_generation = trans->transid;
block_group->disk_cache_state = dcs;
spin_unlock(&block_group->lock);
return ret;
}
int btrfs_setup_space_cache(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *cache, *tmp;
struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_path *path;
if (list_empty(&cur_trans->dirty_bgs) ||
!btrfs_test_opt(root, SPACE_CACHE))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/* Could add new block groups, use _safe just in case */
list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs,
dirty_list) {
if (cache->disk_cache_state == BTRFS_DC_CLEAR)
cache_save_setup(cache, trans, path);
}
btrfs_free_path(path);
return 0;
}
/*
* transaction commit does final block group cache writeback during a
* critical section where nothing is allowed to change the FS. This is
* required in order for the cache to actually match the block group,
* but can introduce a lot of latency into the commit.
*
* So, btrfs_start_dirty_block_groups is here to kick off block group
* cache IO. There's a chance we'll have to redo some of it if the
* block group changes again during the commit, but it greatly reduces
* the commit latency by getting rid of the easy block groups while
* we're still allowing others to join the commit.
*/
int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *cache;
struct btrfs_transaction *cur_trans = trans->transaction;
int ret = 0;
int should_put;
struct btrfs_path *path = NULL;
LIST_HEAD(dirty);
struct list_head *io = &cur_trans->io_bgs;
int num_started = 0;
int loops = 0;
spin_lock(&cur_trans->dirty_bgs_lock);
if (list_empty(&cur_trans->dirty_bgs)) {
spin_unlock(&cur_trans->dirty_bgs_lock);
return 0;
}
list_splice_init(&cur_trans->dirty_bgs, &dirty);
spin_unlock(&cur_trans->dirty_bgs_lock);
again:
/*
* make sure all the block groups on our dirty list actually
* exist
*/
btrfs_create_pending_block_groups(trans, root);
if (!path) {
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
}
/*
* cache_write_mutex is here only to save us from balance or automatic
* removal of empty block groups deleting this block group while we are
* writing out the cache
*/
mutex_lock(&trans->transaction->cache_write_mutex);
while (!list_empty(&dirty)) {
cache = list_first_entry(&dirty,
struct btrfs_block_group_cache,
dirty_list);
/*
* this can happen if something re-dirties a block
* group that is already under IO. Just wait for it to
* finish and then do it all again
*/
if (!list_empty(&cache->io_list)) {
list_del_init(&cache->io_list);
btrfs_wait_cache_io(root, trans, cache,
&cache->io_ctl, path,
cache->key.objectid);
btrfs_put_block_group(cache);
}
/*
* btrfs_wait_cache_io uses the cache->dirty_list to decide
* if it should update the cache_state. Don't delete
* until after we wait.
*
* Since we're not running in the commit critical section
* we need the dirty_bgs_lock to protect from update_block_group
*/
spin_lock(&cur_trans->dirty_bgs_lock);
list_del_init(&cache->dirty_list);
spin_unlock(&cur_trans->dirty_bgs_lock);
should_put = 1;
cache_save_setup(cache, trans, path);
if (cache->disk_cache_state == BTRFS_DC_SETUP) {
cache->io_ctl.inode = NULL;
ret = btrfs_write_out_cache(root, trans, cache, path);
if (ret == 0 && cache->io_ctl.inode) {
num_started++;
should_put = 0;
/*
* the cache_write_mutex is protecting
* the io_list
*/
list_add_tail(&cache->io_list, io);
} else {
/*
* if we failed to write the cache, the
* generation will be bad and life goes on
*/
ret = 0;
}
}
if (!ret) {
ret = write_one_cache_group(trans, root, path, cache);
/*
* Our block group might still be attached to the list
* of new block groups in the transaction handle of some
* other task (struct btrfs_trans_handle->new_bgs). This
* means its block group item isn't yet in the extent
* tree. If this happens ignore the error, as we will
* try again later in the critical section of the
* transaction commit.
*/
if (ret == -ENOENT) {
ret = 0;
spin_lock(&cur_trans->dirty_bgs_lock);
if (list_empty(&cache->dirty_list)) {
list_add_tail(&cache->dirty_list,
&cur_trans->dirty_bgs);
btrfs_get_block_group(cache);
}
spin_unlock(&cur_trans->dirty_bgs_lock);
} else if (ret) {
btrfs_abort_transaction(trans, root, ret);
}
}
/* if its not on the io list, we need to put the block group */
if (should_put)
btrfs_put_block_group(cache);
if (ret)
break;
/*
* Avoid blocking other tasks for too long. It might even save
* us from writing caches for block groups that are going to be
* removed.
*/
mutex_unlock(&trans->transaction->cache_write_mutex);
mutex_lock(&trans->transaction->cache_write_mutex);
}
mutex_unlock(&trans->transaction->cache_write_mutex);
/*
* go through delayed refs for all the stuff we've just kicked off
* and then loop back (just once)
*/
ret = btrfs_run_delayed_refs(trans, root, 0);
if (!ret && loops == 0) {
loops++;
spin_lock(&cur_trans->dirty_bgs_lock);
list_splice_init(&cur_trans->dirty_bgs, &dirty);
/*
* dirty_bgs_lock protects us from concurrent block group
* deletes too (not just cache_write_mutex).
*/
if (!list_empty(&dirty)) {
spin_unlock(&cur_trans->dirty_bgs_lock);
goto again;
}
spin_unlock(&cur_trans->dirty_bgs_lock);
}
btrfs_free_path(path);
return ret;
}
int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *cache;
struct btrfs_transaction *cur_trans = trans->transaction;
int ret = 0;
int should_put;
struct btrfs_path *path;
struct list_head *io = &cur_trans->io_bgs;
int num_started = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* We don't need the lock here since we are protected by the transaction
* commit. We want to do the cache_save_setup first and then run the
* delayed refs to make sure we have the best chance at doing this all
* in one shot.
*/
while (!list_empty(&cur_trans->dirty_bgs)) {
cache = list_first_entry(&cur_trans->dirty_bgs,
struct btrfs_block_group_cache,
dirty_list);
/*
* this can happen if cache_save_setup re-dirties a block
* group that is already under IO. Just wait for it to
* finish and then do it all again
*/
if (!list_empty(&cache->io_list)) {
list_del_init(&cache->io_list);
btrfs_wait_cache_io(root, trans, cache,
&cache->io_ctl, path,
cache->key.objectid);
btrfs_put_block_group(cache);
}
/*
* don't remove from the dirty list until after we've waited
* on any pending IO
*/
list_del_init(&cache->dirty_list);
should_put = 1;
cache_save_setup(cache, trans, path);
if (!ret)
ret = btrfs_run_delayed_refs(trans, root, (unsigned long) -1);
if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) {
cache->io_ctl.inode = NULL;
ret = btrfs_write_out_cache(root, trans, cache, path);
if (ret == 0 && cache->io_ctl.inode) {
num_started++;
should_put = 0;
list_add_tail(&cache->io_list, io);
} else {
/*
* if we failed to write the cache, the
* generation will be bad and life goes on
*/
ret = 0;
}
}
if (!ret) {
ret = write_one_cache_group(trans, root, path, cache);
if (ret)
btrfs_abort_transaction(trans, root, ret);
}
/* if its not on the io list, we need to put the block group */
if (should_put)
btrfs_put_block_group(cache);
}
while (!list_empty(io)) {
cache = list_first_entry(io, struct btrfs_block_group_cache,
io_list);
list_del_init(&cache->io_list);
btrfs_wait_cache_io(root, trans, cache,
&cache->io_ctl, path, cache->key.objectid);
btrfs_put_block_group(cache);
}
btrfs_free_path(path);
return ret;
}
int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr)
{
struct btrfs_block_group_cache *block_group;
int readonly = 0;
block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
if (!block_group || block_group->ro)
readonly = 1;
if (block_group)
btrfs_put_block_group(block_group);
return readonly;
}
static const char *alloc_name(u64 flags)
{
switch (flags) {
case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA:
return "mixed";
case BTRFS_BLOCK_GROUP_METADATA:
return "metadata";
case BTRFS_BLOCK_GROUP_DATA:
return "data";
case BTRFS_BLOCK_GROUP_SYSTEM:
return "system";
default:
WARN_ON(1);
return "invalid-combination";
};
}
static int update_space_info(struct btrfs_fs_info *info, u64 flags,
u64 total_bytes, u64 bytes_used,
struct btrfs_space_info **space_info)
{
struct btrfs_space_info *found;
int i;
int factor;
int ret;
if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
found = __find_space_info(info, flags);
if (found) {
spin_lock(&found->lock);
found->total_bytes += total_bytes;
found->disk_total += total_bytes * factor;
found->bytes_used += bytes_used;
found->disk_used += bytes_used * factor;
if (total_bytes > 0)
found->full = 0;
spin_unlock(&found->lock);
*space_info = found;
return 0;
}
found = kzalloc(sizeof(*found), GFP_NOFS);
if (!found)
return -ENOMEM;
ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL);
if (ret) {
kfree(found);
return ret;
}
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
INIT_LIST_HEAD(&found->block_groups[i]);
init_rwsem(&found->groups_sem);
spin_lock_init(&found->lock);
found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK;
found->total_bytes = total_bytes;
found->disk_total = total_bytes * factor;
found->bytes_used = bytes_used;
found->disk_used = bytes_used * factor;
found->bytes_pinned = 0;
found->bytes_reserved = 0;
found->bytes_readonly = 0;
found->bytes_may_use = 0;
found->full = 0;
found->force_alloc = CHUNK_ALLOC_NO_FORCE;
found->chunk_alloc = 0;
found->flush = 0;
init_waitqueue_head(&found->wait);
INIT_LIST_HEAD(&found->ro_bgs);
ret = kobject_init_and_add(&found->kobj, &space_info_ktype,
info->space_info_kobj, "%s",
alloc_name(found->flags));
if (ret) {
kfree(found);
return ret;
}
*space_info = found;
list_add_rcu(&found->list, &info->space_info);
if (flags & BTRFS_BLOCK_GROUP_DATA)
info->data_sinfo = found;
return ret;
}
static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
{
u64 extra_flags = chunk_to_extended(flags) &
BTRFS_EXTENDED_PROFILE_MASK;
write_seqlock(&fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
fs_info->avail_data_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_METADATA)
fs_info->avail_metadata_alloc_bits |= extra_flags;
if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
fs_info->avail_system_alloc_bits |= extra_flags;
write_sequnlock(&fs_info->profiles_lock);
}
/*
* returns target flags in extended format or 0 if restripe for this
* chunk_type is not in progress
*
* should be called with either volume_mutex or balance_lock held
*/
static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags)
{
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
u64 target = 0;
if (!bctl)
return 0;
if (flags & BTRFS_BLOCK_GROUP_DATA &&
bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) {
target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target;
} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM &&
bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target;
} else if (flags & BTRFS_BLOCK_GROUP_METADATA &&
bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) {
target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target;
}
return target;
}
/*
* @flags: available profiles in extended format (see ctree.h)
*
* Returns reduced profile in chunk format. If profile changing is in
* progress (either running or paused) picks the target profile (if it's
* already available), otherwise falls back to plain reducing.
*/
static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags)
{
u64 num_devices = root->fs_info->fs_devices->rw_devices;
u64 target;
u64 tmp;
/*
* see if restripe for this chunk_type is in progress, if so
* try to reduce to the target profile
*/
spin_lock(&root->fs_info->balance_lock);
target = get_restripe_target(root->fs_info, flags);
if (target) {
/* pick target profile only if it's already available */
if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) {
spin_unlock(&root->fs_info->balance_lock);
return extended_to_chunk(target);
}
}
spin_unlock(&root->fs_info->balance_lock);
/* First, mask out the RAID levels which aren't possible */
if (num_devices == 1)
flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID5);
if (num_devices < 3)
flags &= ~BTRFS_BLOCK_GROUP_RAID6;
if (num_devices < 4)
flags &= ~BTRFS_BLOCK_GROUP_RAID10;
tmp = flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID10);
flags &= ~tmp;
if (tmp & BTRFS_BLOCK_GROUP_RAID6)
tmp = BTRFS_BLOCK_GROUP_RAID6;
else if (tmp & BTRFS_BLOCK_GROUP_RAID5)
tmp = BTRFS_BLOCK_GROUP_RAID5;
else if (tmp & BTRFS_BLOCK_GROUP_RAID10)
tmp = BTRFS_BLOCK_GROUP_RAID10;
else if (tmp & BTRFS_BLOCK_GROUP_RAID1)
tmp = BTRFS_BLOCK_GROUP_RAID1;
else if (tmp & BTRFS_BLOCK_GROUP_RAID0)
tmp = BTRFS_BLOCK_GROUP_RAID0;
return extended_to_chunk(flags | tmp);
}
static u64 get_alloc_profile(struct btrfs_root *root, u64 orig_flags)
{
unsigned seq;
u64 flags;
do {
flags = orig_flags;
seq = read_seqbegin(&root->fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
flags |= root->fs_info->avail_data_alloc_bits;
else if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
flags |= root->fs_info->avail_system_alloc_bits;
else if (flags & BTRFS_BLOCK_GROUP_METADATA)
flags |= root->fs_info->avail_metadata_alloc_bits;
} while (read_seqretry(&root->fs_info->profiles_lock, seq));
return btrfs_reduce_alloc_profile(root, flags);
}
u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data)
{
u64 flags;
u64 ret;
if (data)
flags = BTRFS_BLOCK_GROUP_DATA;
else if (root == root->fs_info->chunk_root)
flags = BTRFS_BLOCK_GROUP_SYSTEM;
else
flags = BTRFS_BLOCK_GROUP_METADATA;
ret = get_alloc_profile(root, flags);
return ret;
}
/*
* This will check the space that the inode allocates from to make sure we have
* enough space for bytes.
*/
int btrfs_check_data_free_space(struct inode *inode, u64 bytes, u64 write_bytes)
{
struct btrfs_space_info *data_sinfo;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_fs_info *fs_info = root->fs_info;
u64 used;
int ret = 0;
int need_commit = 2;
int have_pinned_space;
/* make sure bytes are sectorsize aligned */
bytes = ALIGN(bytes, root->sectorsize);
if (btrfs_is_free_space_inode(inode)) {
need_commit = 0;
ASSERT(current->journal_info);
}
data_sinfo = fs_info->data_sinfo;
if (!data_sinfo)
goto alloc;
again:
/* make sure we have enough space to handle the data first */
spin_lock(&data_sinfo->lock);
used = data_sinfo->bytes_used + data_sinfo->bytes_reserved +
data_sinfo->bytes_pinned + data_sinfo->bytes_readonly +
data_sinfo->bytes_may_use;
if (used + bytes > data_sinfo->total_bytes) {
struct btrfs_trans_handle *trans;
/*
* if we don't have enough free bytes in this space then we need
* to alloc a new chunk.
*/
if (!data_sinfo->full) {
u64 alloc_target;
data_sinfo->force_alloc = CHUNK_ALLOC_FORCE;
spin_unlock(&data_sinfo->lock);
alloc:
alloc_target = btrfs_get_alloc_profile(root, 1);
/*
* It is ugly that we don't call nolock join
* transaction for the free space inode case here.
* But it is safe because we only do the data space
* reservation for the free space cache in the
* transaction context, the common join transaction
* just increase the counter of the current transaction
* handler, doesn't try to acquire the trans_lock of
* the fs.
*/
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
alloc_target,
CHUNK_ALLOC_NO_FORCE);
btrfs_end_transaction(trans, root);
if (ret < 0) {
if (ret != -ENOSPC)
return ret;
else {
have_pinned_space = 1;
goto commit_trans;
}
}
if (!data_sinfo)
data_sinfo = fs_info->data_sinfo;
goto again;
}
/*
* If we don't have enough pinned space to deal with this
* allocation, and no removed chunk in current transaction,
* don't bother committing the transaction.
*/
have_pinned_space = percpu_counter_compare(
&data_sinfo->total_bytes_pinned,
used + bytes - data_sinfo->total_bytes);
spin_unlock(&data_sinfo->lock);
/* commit the current transaction and try again */
commit_trans:
if (need_commit &&
!atomic_read(&root->fs_info->open_ioctl_trans)) {
need_commit--;
if (need_commit > 0)
btrfs_wait_ordered_roots(fs_info, -1);
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
if (have_pinned_space >= 0 ||
trans->transaction->have_free_bgs ||
need_commit > 0) {
ret = btrfs_commit_transaction(trans, root);
if (ret)
return ret;
/*
* make sure that all running delayed iput are
* done
*/
down_write(&root->fs_info->delayed_iput_sem);
up_write(&root->fs_info->delayed_iput_sem);
goto again;
} else {
btrfs_end_transaction(trans, root);
}
}
trace_btrfs_space_reservation(root->fs_info,
"space_info:enospc",
data_sinfo->flags, bytes, 1);
return -ENOSPC;
}
ret = btrfs_qgroup_reserve(root, write_bytes);
if (ret)
goto out;
data_sinfo->bytes_may_use += bytes;
trace_btrfs_space_reservation(root->fs_info, "space_info",
data_sinfo->flags, bytes, 1);
out:
spin_unlock(&data_sinfo->lock);
return ret;
}
/*
* Called if we need to clear a data reservation for this inode.
*/
void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_space_info *data_sinfo;
/* make sure bytes are sectorsize aligned */
bytes = ALIGN(bytes, root->sectorsize);
data_sinfo = root->fs_info->data_sinfo;
spin_lock(&data_sinfo->lock);
WARN_ON(data_sinfo->bytes_may_use < bytes);
data_sinfo->bytes_may_use -= bytes;
trace_btrfs_space_reservation(root->fs_info, "space_info",
data_sinfo->flags, bytes, 0);
spin_unlock(&data_sinfo->lock);
}
static void force_metadata_allocation(struct btrfs_fs_info *info)
{
struct list_head *head = &info->space_info;
struct btrfs_space_info *found;
rcu_read_lock();
list_for_each_entry_rcu(found, head, list) {
if (found->flags & BTRFS_BLOCK_GROUP_METADATA)
found->force_alloc = CHUNK_ALLOC_FORCE;
}
rcu_read_unlock();
}
static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global)
{
return (global->size << 1);
}
static int should_alloc_chunk(struct btrfs_root *root,
struct btrfs_space_info *sinfo, int force)
{
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly;
u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved;
u64 thresh;
if (force == CHUNK_ALLOC_FORCE)
return 1;
/*
* We need to take into account the global rsv because for all intents
* and purposes it's used space. Don't worry about locking the
* global_rsv, it doesn't change except when the transaction commits.
*/
if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA)
num_allocated += calc_global_rsv_need_space(global_rsv);
/*
* in limited mode, we want to have some free space up to
* about 1% of the FS size.
*/
if (force == CHUNK_ALLOC_LIMITED) {
thresh = btrfs_super_total_bytes(root->fs_info->super_copy);
thresh = max_t(u64, 64 * 1024 * 1024,
div_factor_fine(thresh, 1));
if (num_bytes - num_allocated < thresh)
return 1;
}
if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8))
return 0;
return 1;
}
static u64 get_profile_num_devs(struct btrfs_root *root, u64 type)
{
u64 num_dev;
if (type & (BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6))
num_dev = root->fs_info->fs_devices->rw_devices;
else if (type & BTRFS_BLOCK_GROUP_RAID1)
num_dev = 2;
else
num_dev = 1; /* DUP or single */
return num_dev;
}
/*
* If @is_allocation is true, reserve space in the system space info necessary
* for allocating a chunk, otherwise if it's false, reserve space necessary for
* removing a chunk.
*/
void check_system_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 type)
{
struct btrfs_space_info *info;
u64 left;
u64 thresh;
int ret = 0;
u64 num_devs;
/*
* Needed because we can end up allocating a system chunk and for an
* atomic and race free space reservation in the chunk block reserve.
*/
ASSERT(mutex_is_locked(&root->fs_info->chunk_mutex));
info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
spin_lock(&info->lock);
left = info->total_bytes - info->bytes_used - info->bytes_pinned -
info->bytes_reserved - info->bytes_readonly -
info->bytes_may_use;
spin_unlock(&info->lock);
num_devs = get_profile_num_devs(root, type);
/* num_devs device items to update and 1 chunk item to add or remove */
thresh = btrfs_calc_trunc_metadata_size(root, num_devs) +
btrfs_calc_trans_metadata_size(root, 1);
if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) {
btrfs_info(root->fs_info, "left=%llu, need=%llu, flags=%llu",
left, thresh, type);
dump_space_info(info, 0, 0);
}
if (left < thresh) {
u64 flags;
flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0);
/*
* Ignore failure to create system chunk. We might end up not
* needing it, as we might not need to COW all nodes/leafs from
* the paths we visit in the chunk tree (they were already COWed
* or created in the current transaction for example).
*/
ret = btrfs_alloc_chunk(trans, root, flags);
}
if (!ret) {
ret = btrfs_block_rsv_add(root->fs_info->chunk_root,
&root->fs_info->chunk_block_rsv,
thresh, BTRFS_RESERVE_NO_FLUSH);
if (!ret)
trans->chunk_bytes_reserved += thresh;
}
}
static int do_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 flags, int force)
{
struct btrfs_space_info *space_info;
struct btrfs_fs_info *fs_info = extent_root->fs_info;
int wait_for_alloc = 0;
int ret = 0;
/* Don't re-enter if we're already allocating a chunk */
if (trans->allocating_chunk)
return -ENOSPC;
space_info = __find_space_info(extent_root->fs_info, flags);
if (!space_info) {
ret = update_space_info(extent_root->fs_info, flags,
0, 0, &space_info);
BUG_ON(ret); /* -ENOMEM */
}
BUG_ON(!space_info); /* Logic error */
again:
spin_lock(&space_info->lock);
if (force < space_info->force_alloc)
force = space_info->force_alloc;
if (space_info->full) {
if (should_alloc_chunk(extent_root, space_info, force))
ret = -ENOSPC;
else
ret = 0;
spin_unlock(&space_info->lock);
return ret;
}
if (!should_alloc_chunk(extent_root, space_info, force)) {
spin_unlock(&space_info->lock);
return 0;
} else if (space_info->chunk_alloc) {
wait_for_alloc = 1;
} else {
space_info->chunk_alloc = 1;
}
spin_unlock(&space_info->lock);
mutex_lock(&fs_info->chunk_mutex);
/*
* The chunk_mutex is held throughout the entirety of a chunk
* allocation, so once we've acquired the chunk_mutex we know that the
* other guy is done and we need to recheck and see if we should
* allocate.
*/
if (wait_for_alloc) {
mutex_unlock(&fs_info->chunk_mutex);
wait_for_alloc = 0;
goto again;
}
trans->allocating_chunk = true;
/*
* If we have mixed data/metadata chunks we want to make sure we keep
* allocating mixed chunks instead of individual chunks.
*/
if (btrfs_mixed_space_info(space_info))
flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA);
/*
* if we're doing a data chunk, go ahead and make sure that
* we keep a reasonable number of metadata chunks allocated in the
* FS as well.
*/
if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) {
fs_info->data_chunk_allocations++;
if (!(fs_info->data_chunk_allocations %
fs_info->metadata_ratio))
force_metadata_allocation(fs_info);
}
/*
* Check if we have enough space in SYSTEM chunk because we may need
* to update devices.
*/
check_system_chunk(trans, extent_root, flags);
ret = btrfs_alloc_chunk(trans, extent_root, flags);
trans->allocating_chunk = false;
spin_lock(&space_info->lock);
if (ret < 0 && ret != -ENOSPC)
goto out;
if (ret)
space_info->full = 1;
else
ret = 1;
space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
out:
space_info->chunk_alloc = 0;
spin_unlock(&space_info->lock);
mutex_unlock(&fs_info->chunk_mutex);
/*
* When we allocate a new chunk we reserve space in the chunk block
* reserve to make sure we can COW nodes/leafs in the chunk tree or
* add new nodes/leafs to it if we end up needing to do it when
* inserting the chunk item and updating device items as part of the
* second phase of chunk allocation, performed by
* btrfs_finish_chunk_alloc(). So make sure we don't accumulate a
* large number of new block groups to create in our transaction
* handle's new_bgs list to avoid exhausting the chunk block reserve
* in extreme cases - like having a single transaction create many new
* block groups when starting to write out the free space caches of all
* the block groups that were made dirty during the lifetime of the
* transaction.
*/
if (trans->chunk_bytes_reserved >= (2 * 1024 * 1024ull)) {
btrfs_create_pending_block_groups(trans, trans->root);
btrfs_trans_release_chunk_metadata(trans);
}
return ret;
}
static int can_overcommit(struct btrfs_root *root,
struct btrfs_space_info *space_info, u64 bytes,
enum btrfs_reserve_flush_enum flush)
{
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
u64 profile = btrfs_get_alloc_profile(root, 0);
u64 space_size;
u64 avail;
u64 used;
used = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly;
/*
* We only want to allow over committing if we have lots of actual space
* free, but if we don't have enough space to handle the global reserve
* space then we could end up having a real enospc problem when trying
* to allocate a chunk or some other such important allocation.
*/
spin_lock(&global_rsv->lock);
space_size = calc_global_rsv_need_space(global_rsv);
spin_unlock(&global_rsv->lock);
if (used + space_size >= space_info->total_bytes)
return 0;
used += space_info->bytes_may_use;
spin_lock(&root->fs_info->free_chunk_lock);
avail = root->fs_info->free_chunk_space;
spin_unlock(&root->fs_info->free_chunk_lock);
/*
* If we have dup, raid1 or raid10 then only half of the free
* space is actually useable. For raid56, the space info used
* doesn't include the parity drive, so we don't have to
* change the math
*/
if (profile & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
avail >>= 1;
/*
* If we aren't flushing all things, let us overcommit up to
* 1/2th of the space. If we can flush, don't let us overcommit
* too much, let it overcommit up to 1/8 of the space.
*/
if (flush == BTRFS_RESERVE_FLUSH_ALL)
avail >>= 3;
else
avail >>= 1;
if (used + bytes < space_info->total_bytes + avail)
return 1;
return 0;
}
static void btrfs_writeback_inodes_sb_nr(struct btrfs_root *root,
unsigned long nr_pages, int nr_items)
{
struct super_block *sb = root->fs_info->sb;
if (down_read_trylock(&sb->s_umount)) {
writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE);
up_read(&sb->s_umount);
} else {
/*
* We needn't worry the filesystem going from r/w to r/o though
* we don't acquire ->s_umount mutex, because the filesystem
* should guarantee the delalloc inodes list be empty after
* the filesystem is readonly(all dirty pages are written to
* the disk).
*/
btrfs_start_delalloc_roots(root->fs_info, 0, nr_items);
if (!current->journal_info)
btrfs_wait_ordered_roots(root->fs_info, nr_items);
}
}
static inline int calc_reclaim_items_nr(struct btrfs_root *root, u64 to_reclaim)
{
u64 bytes;
int nr;
bytes = btrfs_calc_trans_metadata_size(root, 1);
nr = (int)div64_u64(to_reclaim, bytes);
if (!nr)
nr = 1;
return nr;
}
#define EXTENT_SIZE_PER_ITEM (256 * 1024)
/*
* shrink metadata reservation for delalloc
*/
static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig,
bool wait_ordered)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_space_info *space_info;
struct btrfs_trans_handle *trans;
u64 delalloc_bytes;
u64 max_reclaim;
long time_left;
unsigned long nr_pages;
int loops;
int items;
enum btrfs_reserve_flush_enum flush;
/* Calc the number of the pages we need flush for space reservation */
items = calc_reclaim_items_nr(root, to_reclaim);
to_reclaim = items * EXTENT_SIZE_PER_ITEM;
trans = (struct btrfs_trans_handle *)current->journal_info;
block_rsv = &root->fs_info->delalloc_block_rsv;
space_info = block_rsv->space_info;
delalloc_bytes = percpu_counter_sum_positive(
&root->fs_info->delalloc_bytes);
if (delalloc_bytes == 0) {
if (trans)
return;
if (wait_ordered)
btrfs_wait_ordered_roots(root->fs_info, items);
return;
}
loops = 0;
while (delalloc_bytes && loops < 3) {
max_reclaim = min(delalloc_bytes, to_reclaim);
nr_pages = max_reclaim >> PAGE_CACHE_SHIFT;
btrfs_writeback_inodes_sb_nr(root, nr_pages, items);
/*
* We need to wait for the async pages to actually start before
* we do anything.
*/
max_reclaim = atomic_read(&root->fs_info->async_delalloc_pages);
if (!max_reclaim)
goto skip_async;
if (max_reclaim <= nr_pages)
max_reclaim = 0;
else
max_reclaim -= nr_pages;
wait_event(root->fs_info->async_submit_wait,
atomic_read(&root->fs_info->async_delalloc_pages) <=
(int)max_reclaim);
skip_async:
if (!trans)
flush = BTRFS_RESERVE_FLUSH_ALL;
else
flush = BTRFS_RESERVE_NO_FLUSH;
spin_lock(&space_info->lock);
if (can_overcommit(root, space_info, orig, flush)) {
spin_unlock(&space_info->lock);
break;
}
spin_unlock(&space_info->lock);
loops++;
if (wait_ordered && !trans) {
btrfs_wait_ordered_roots(root->fs_info, items);
} else {
time_left = schedule_timeout_killable(1);
if (time_left)
break;
}
delalloc_bytes = percpu_counter_sum_positive(
&root->fs_info->delalloc_bytes);
}
}
/**
* maybe_commit_transaction - possibly commit the transaction if its ok to
* @root - the root we're allocating for
* @bytes - the number of bytes we want to reserve
* @force - force the commit
*
* This will check to make sure that committing the transaction will actually
* get us somewhere and then commit the transaction if it does. Otherwise it
* will return -ENOSPC.
*/
static int may_commit_transaction(struct btrfs_root *root,
struct btrfs_space_info *space_info,
u64 bytes, int force)
{
struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv;
struct btrfs_trans_handle *trans;
trans = (struct btrfs_trans_handle *)current->journal_info;
if (trans)
return -EAGAIN;
if (force)
goto commit;
/* See if there is enough pinned space to make this reservation */
if (percpu_counter_compare(&space_info->total_bytes_pinned,
bytes) >= 0)
goto commit;
/*
* See if there is some space in the delayed insertion reservation for
* this reservation.
*/
if (space_info != delayed_rsv->space_info)
return -ENOSPC;
spin_lock(&delayed_rsv->lock);
if (percpu_counter_compare(&space_info->total_bytes_pinned,
bytes - delayed_rsv->size) >= 0) {
spin_unlock(&delayed_rsv->lock);
return -ENOSPC;
}
spin_unlock(&delayed_rsv->lock);
commit:
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return -ENOSPC;
return btrfs_commit_transaction(trans, root);
}
enum flush_state {
FLUSH_DELAYED_ITEMS_NR = 1,
FLUSH_DELAYED_ITEMS = 2,
FLUSH_DELALLOC = 3,
FLUSH_DELALLOC_WAIT = 4,
ALLOC_CHUNK = 5,
COMMIT_TRANS = 6,
};
static int flush_space(struct btrfs_root *root,
struct btrfs_space_info *space_info, u64 num_bytes,
u64 orig_bytes, int state)
{
struct btrfs_trans_handle *trans;
int nr;
int ret = 0;
switch (state) {
case FLUSH_DELAYED_ITEMS_NR:
case FLUSH_DELAYED_ITEMS:
if (state == FLUSH_DELAYED_ITEMS_NR)
nr = calc_reclaim_items_nr(root, num_bytes) * 2;
else
nr = -1;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
ret = btrfs_run_delayed_items_nr(trans, root, nr);
btrfs_end_transaction(trans, root);
break;
case FLUSH_DELALLOC:
case FLUSH_DELALLOC_WAIT:
shrink_delalloc(root, num_bytes * 2, orig_bytes,
state == FLUSH_DELALLOC_WAIT);
break;
case ALLOC_CHUNK:
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
ret = do_chunk_alloc(trans, root->fs_info->extent_root,
btrfs_get_alloc_profile(root, 0),
CHUNK_ALLOC_NO_FORCE);
btrfs_end_transaction(trans, root);
if (ret == -ENOSPC)
ret = 0;
break;
case COMMIT_TRANS:
ret = may_commit_transaction(root, space_info, orig_bytes, 0);
break;
default:
ret = -ENOSPC;
break;
}
return ret;
}
static inline u64
btrfs_calc_reclaim_metadata_size(struct btrfs_root *root,
struct btrfs_space_info *space_info)
{
u64 used;
u64 expected;
u64 to_reclaim;
to_reclaim = min_t(u64, num_online_cpus() * 1024 * 1024,
16 * 1024 * 1024);
spin_lock(&space_info->lock);
if (can_overcommit(root, space_info, to_reclaim,
BTRFS_RESERVE_FLUSH_ALL)) {
to_reclaim = 0;
goto out;
}
used = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
space_info->bytes_may_use;
if (can_overcommit(root, space_info, 1024 * 1024,
BTRFS_RESERVE_FLUSH_ALL))
expected = div_factor_fine(space_info->total_bytes, 95);
else
expected = div_factor_fine(space_info->total_bytes, 90);
if (used > expected)
to_reclaim = used - expected;
else
to_reclaim = 0;
to_reclaim = min(to_reclaim, space_info->bytes_may_use +
space_info->bytes_reserved);
out:
spin_unlock(&space_info->lock);
return to_reclaim;
}
static inline int need_do_async_reclaim(struct btrfs_space_info *space_info,
struct btrfs_fs_info *fs_info, u64 used)
{
u64 thresh = div_factor_fine(space_info->total_bytes, 98);
/* If we're just plain full then async reclaim just slows us down. */
if (space_info->bytes_used >= thresh)
return 0;
return (used >= thresh && !btrfs_fs_closing(fs_info) &&
!test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state));
}
static int btrfs_need_do_async_reclaim(struct btrfs_space_info *space_info,
struct btrfs_fs_info *fs_info,
int flush_state)
{
u64 used;
spin_lock(&space_info->lock);
/*
* We run out of space and have not got any free space via flush_space,
* so don't bother doing async reclaim.
*/
if (flush_state > COMMIT_TRANS && space_info->full) {
spin_unlock(&space_info->lock);
return 0;
}
used = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
space_info->bytes_may_use;
if (need_do_async_reclaim(space_info, fs_info, used)) {
spin_unlock(&space_info->lock);
return 1;
}
spin_unlock(&space_info->lock);
return 0;
}
static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
{
struct btrfs_fs_info *fs_info;
struct btrfs_space_info *space_info;
u64 to_reclaim;
int flush_state;
fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work);
space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root,
space_info);
if (!to_reclaim)
return;
flush_state = FLUSH_DELAYED_ITEMS_NR;
do {
flush_space(fs_info->fs_root, space_info, to_reclaim,
to_reclaim, flush_state);
flush_state++;
if (!btrfs_need_do_async_reclaim(space_info, fs_info,
flush_state))
return;
} while (flush_state < COMMIT_TRANS);
}
void btrfs_init_async_reclaim_work(struct work_struct *work)
{
INIT_WORK(work, btrfs_async_reclaim_metadata_space);
}
/**
* reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
* @root - the root we're allocating for
* @block_rsv - the block_rsv we're allocating for
* @orig_bytes - the number of bytes we want
* @flush - whether or not we can flush to make our reservation
*
* This will reserve orgi_bytes number of bytes from the space info associated
* with the block_rsv. If there is not enough space it will make an attempt to
* flush out space to make room. It will do this by flushing delalloc if
* possible or committing the transaction. If flush is 0 then no attempts to
* regain reservations will be made and this will fail if there is not enough
* space already.
*/
static int reserve_metadata_bytes(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 orig_bytes,
enum btrfs_reserve_flush_enum flush)
{
struct btrfs_space_info *space_info = block_rsv->space_info;
u64 used;
u64 num_bytes = orig_bytes;
int flush_state = FLUSH_DELAYED_ITEMS_NR;
int ret = 0;
bool flushing = false;
again:
ret = 0;
spin_lock(&space_info->lock);
/*
* We only want to wait if somebody other than us is flushing and we
* are actually allowed to flush all things.
*/
while (flush == BTRFS_RESERVE_FLUSH_ALL && !flushing &&
space_info->flush) {
spin_unlock(&space_info->lock);
/*
* If we have a trans handle we can't wait because the flusher
* may have to commit the transaction, which would mean we would
* deadlock since we are waiting for the flusher to finish, but
* hold the current transaction open.
*/
if (current->journal_info)
return -EAGAIN;
ret = wait_event_killable(space_info->wait, !space_info->flush);
/* Must have been killed, return */
if (ret)
return -EINTR;
spin_lock(&space_info->lock);
}
ret = -ENOSPC;
used = space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
space_info->bytes_may_use;
/*
* The idea here is that we've not already over-reserved the block group
* then we can go ahead and save our reservation first and then start
* flushing if we need to. Otherwise if we've already overcommitted
* lets start flushing stuff first and then come back and try to make
* our reservation.
*/
if (used <= space_info->total_bytes) {
if (used + orig_bytes <= space_info->total_bytes) {
space_info->bytes_may_use += orig_bytes;
trace_btrfs_space_reservation(root->fs_info,
"space_info", space_info->flags, orig_bytes, 1);
ret = 0;
} else {
/*
* Ok set num_bytes to orig_bytes since we aren't
* overocmmitted, this way we only try and reclaim what
* we need.
*/
num_bytes = orig_bytes;
}
} else {
/*
* Ok we're over committed, set num_bytes to the overcommitted
* amount plus the amount of bytes that we need for this
* reservation.
*/
num_bytes = used - space_info->total_bytes +
(orig_bytes * 2);
}
if (ret && can_overcommit(root, space_info, orig_bytes, flush)) {
space_info->bytes_may_use += orig_bytes;
trace_btrfs_space_reservation(root->fs_info, "space_info",
space_info->flags, orig_bytes,
1);
ret = 0;
}
/*
* Couldn't make our reservation, save our place so while we're trying
* to reclaim space we can actually use it instead of somebody else
* stealing it from us.
*
* We make the other tasks wait for the flush only when we can flush
* all things.
*/
if (ret && flush != BTRFS_RESERVE_NO_FLUSH) {
flushing = true;
space_info->flush = 1;
} else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) {
used += orig_bytes;
/*
* We will do the space reservation dance during log replay,
* which means we won't have fs_info->fs_root set, so don't do
* the async reclaim as we will panic.
*/
if (!root->fs_info->log_root_recovering &&
need_do_async_reclaim(space_info, root->fs_info, used) &&
!work_busy(&root->fs_info->async_reclaim_work))
queue_work(system_unbound_wq,
&root->fs_info->async_reclaim_work);
}
spin_unlock(&space_info->lock);
if (!ret || flush == BTRFS_RESERVE_NO_FLUSH)
goto out;
ret = flush_space(root, space_info, num_bytes, orig_bytes,
flush_state);
flush_state++;
/*
* If we are FLUSH_LIMIT, we can not flush delalloc, or the deadlock
* would happen. So skip delalloc flush.
*/
if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
(flush_state == FLUSH_DELALLOC ||
flush_state == FLUSH_DELALLOC_WAIT))
flush_state = ALLOC_CHUNK;
if (!ret)
goto again;
else if (flush == BTRFS_RESERVE_FLUSH_LIMIT &&
flush_state < COMMIT_TRANS)
goto again;
else if (flush == BTRFS_RESERVE_FLUSH_ALL &&
flush_state <= COMMIT_TRANS)
goto again;
out:
if (ret == -ENOSPC &&
unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) {
struct btrfs_block_rsv *global_rsv =
&root->fs_info->global_block_rsv;
if (block_rsv != global_rsv &&
!block_rsv_use_bytes(global_rsv, orig_bytes))
ret = 0;
}
if (ret == -ENOSPC)
trace_btrfs_space_reservation(root->fs_info,
"space_info:enospc",
space_info->flags, orig_bytes, 1);
if (flushing) {
spin_lock(&space_info->lock);
space_info->flush = 0;
wake_up_all(&space_info->wait);
spin_unlock(&space_info->lock);
}
return ret;
}
static struct btrfs_block_rsv *get_block_rsv(
const struct btrfs_trans_handle *trans,
const struct btrfs_root *root)
{
struct btrfs_block_rsv *block_rsv = NULL;
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
block_rsv = trans->block_rsv;
if (root == root->fs_info->csum_root && trans->adding_csums)
block_rsv = trans->block_rsv;
if (root == root->fs_info->uuid_root)
block_rsv = trans->block_rsv;
if (!block_rsv)
block_rsv = root->block_rsv;
if (!block_rsv)
block_rsv = &root->fs_info->empty_block_rsv;
return block_rsv;
}
static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv,
u64 num_bytes)
{
int ret = -ENOSPC;
spin_lock(&block_rsv->lock);
if (block_rsv->reserved >= num_bytes) {
block_rsv->reserved -= num_bytes;
if (block_rsv->reserved < block_rsv->size)
block_rsv->full = 0;
ret = 0;
}
spin_unlock(&block_rsv->lock);
return ret;
}
static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
u64 num_bytes, int update_size)
{
spin_lock(&block_rsv->lock);
block_rsv->reserved += num_bytes;
if (update_size)
block_rsv->size += num_bytes;
else if (block_rsv->reserved >= block_rsv->size)
block_rsv->full = 1;
spin_unlock(&block_rsv->lock);
}
int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *dest, u64 num_bytes,
int min_factor)
{
struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
u64 min_bytes;
if (global_rsv->space_info != dest->space_info)
return -ENOSPC;
spin_lock(&global_rsv->lock);
min_bytes = div_factor(global_rsv->size, min_factor);
if (global_rsv->reserved < min_bytes + num_bytes) {
spin_unlock(&global_rsv->lock);
return -ENOSPC;
}
global_rsv->reserved -= num_bytes;
if (global_rsv->reserved < global_rsv->size)
global_rsv->full = 0;
spin_unlock(&global_rsv->lock);
block_rsv_add_bytes(dest, num_bytes, 1);
return 0;
}
static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *block_rsv,
struct btrfs_block_rsv *dest, u64 num_bytes)
{
struct btrfs_space_info *space_info = block_rsv->space_info;
spin_lock(&block_rsv->lock);
if (num_bytes == (u64)-1)
num_bytes = block_rsv->size;
block_rsv->size -= num_bytes;
if (block_rsv->reserved >= block_rsv->size) {
num_bytes = block_rsv->reserved - block_rsv->size;
block_rsv->reserved = block_rsv->size;
block_rsv->full = 1;
} else {
num_bytes = 0;
}
spin_unlock(&block_rsv->lock);
if (num_bytes > 0) {
if (dest) {
spin_lock(&dest->lock);
if (!dest->full) {
u64 bytes_to_add;
bytes_to_add = dest->size - dest->reserved;
bytes_to_add = min(num_bytes, bytes_to_add);
dest->reserved += bytes_to_add;
if (dest->reserved >= dest->size)
dest->full = 1;
num_bytes -= bytes_to_add;
}
spin_unlock(&dest->lock);
}
if (num_bytes) {
spin_lock(&space_info->lock);
space_info->bytes_may_use -= num_bytes;
trace_btrfs_space_reservation(fs_info, "space_info",
space_info->flags, num_bytes, 0);
spin_unlock(&space_info->lock);
}
}
}
static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src,
struct btrfs_block_rsv *dst, u64 num_bytes)
{
int ret;
ret = block_rsv_use_bytes(src, num_bytes);
if (ret)
return ret;
block_rsv_add_bytes(dst, num_bytes, 1);
return 0;
}
void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type)
{
memset(rsv, 0, sizeof(*rsv));
spin_lock_init(&rsv->lock);
rsv->type = type;
}
struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root,
unsigned short type)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_fs_info *fs_info = root->fs_info;
block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
if (!block_rsv)
return NULL;
btrfs_init_block_rsv(block_rsv, type);
block_rsv->space_info = __find_space_info(fs_info,
BTRFS_BLOCK_GROUP_METADATA);
return block_rsv;
}
void btrfs_free_block_rsv(struct btrfs_root *root,
struct btrfs_block_rsv *rsv)
{
if (!rsv)
return;
btrfs_block_rsv_release(root, rsv, (u64)-1);
kfree(rsv);
}
void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv)
{
kfree(rsv);
}
int btrfs_block_rsv_add(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, u64 num_bytes,
enum btrfs_reserve_flush_enum flush)
{
int ret;
if (num_bytes == 0)
return 0;
ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
if (!ret) {
block_rsv_add_bytes(block_rsv, num_bytes, 1);
return 0;
}
return ret;
}
int btrfs_block_rsv_check(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, int min_factor)
{
u64 num_bytes = 0;
int ret = -ENOSPC;
if (!block_rsv)
return 0;
spin_lock(&block_rsv->lock);
num_bytes = div_factor(block_rsv->size, min_factor);
if (block_rsv->reserved >= num_bytes)
ret = 0;
spin_unlock(&block_rsv->lock);
return ret;
}
int btrfs_block_rsv_refill(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, u64 min_reserved,
enum btrfs_reserve_flush_enum flush)
{
u64 num_bytes = 0;
int ret = -ENOSPC;
if (!block_rsv)
return 0;
spin_lock(&block_rsv->lock);
num_bytes = min_reserved;
if (block_rsv->reserved >= num_bytes)
ret = 0;
else
num_bytes -= block_rsv->reserved;
spin_unlock(&block_rsv->lock);
if (!ret)
return 0;
ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush);
if (!ret) {
block_rsv_add_bytes(block_rsv, num_bytes, 0);
return 0;
}
return ret;
}
int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
struct btrfs_block_rsv *dst_rsv,
u64 num_bytes)
{
return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
}
void btrfs_block_rsv_release(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 num_bytes)
{
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
if (global_rsv == block_rsv ||
block_rsv->space_info != global_rsv->space_info)
global_rsv = NULL;
block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv,
num_bytes);
}
/*
* helper to calculate size of global block reservation.
* the desired value is sum of space used by extent tree,
* checksum tree and root tree
*/
static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *sinfo;
u64 num_bytes;
u64 meta_used;
u64 data_used;
int csum_size = btrfs_super_csum_size(fs_info->super_copy);
sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA);
spin_lock(&sinfo->lock);
data_used = sinfo->bytes_used;
spin_unlock(&sinfo->lock);
sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
spin_lock(&sinfo->lock);
if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA)
data_used = 0;
meta_used = sinfo->bytes_used;
spin_unlock(&sinfo->lock);
num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) *
csum_size * 2;
num_bytes += div_u64(data_used + meta_used, 50);
if (num_bytes * 3 > meta_used)
num_bytes = div_u64(meta_used, 3);
return ALIGN(num_bytes, fs_info->extent_root->nodesize << 10);
}
static void update_global_block_rsv(struct btrfs_fs_info *fs_info)
{
struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
struct btrfs_space_info *sinfo = block_rsv->space_info;
u64 num_bytes;
num_bytes = calc_global_metadata_size(fs_info);
spin_lock(&sinfo->lock);
spin_lock(&block_rsv->lock);
block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024);
num_bytes = sinfo->bytes_used + sinfo->bytes_pinned +
sinfo->bytes_reserved + sinfo->bytes_readonly +
sinfo->bytes_may_use;
if (sinfo->total_bytes > num_bytes) {
num_bytes = sinfo->total_bytes - num_bytes;
block_rsv->reserved += num_bytes;
sinfo->bytes_may_use += num_bytes;
trace_btrfs_space_reservation(fs_info, "space_info",
sinfo->flags, num_bytes, 1);
}
if (block_rsv->reserved >= block_rsv->size) {
num_bytes = block_rsv->reserved - block_rsv->size;
sinfo->bytes_may_use -= num_bytes;
trace_btrfs_space_reservation(fs_info, "space_info",
sinfo->flags, num_bytes, 0);
block_rsv->reserved = block_rsv->size;
block_rsv->full = 1;
}
spin_unlock(&block_rsv->lock);
spin_unlock(&sinfo->lock);
}
static void init_global_block_rsv(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *space_info;
space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM);
fs_info->chunk_block_rsv.space_info = space_info;
space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA);
fs_info->global_block_rsv.space_info = space_info;
fs_info->delalloc_block_rsv.space_info = space_info;
fs_info->trans_block_rsv.space_info = space_info;
fs_info->empty_block_rsv.space_info = space_info;
fs_info->delayed_block_rsv.space_info = space_info;
fs_info->extent_root->block_rsv = &fs_info->global_block_rsv;
fs_info->csum_root->block_rsv = &fs_info->global_block_rsv;
fs_info->dev_root->block_rsv = &fs_info->global_block_rsv;
fs_info->tree_root->block_rsv = &fs_info->global_block_rsv;
if (fs_info->quota_root)
fs_info->quota_root->block_rsv = &fs_info->global_block_rsv;
fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv;
update_global_block_rsv(fs_info);
}
static void release_global_block_rsv(struct btrfs_fs_info *fs_info)
{
block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL,
(u64)-1);
WARN_ON(fs_info->delalloc_block_rsv.size > 0);
WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
WARN_ON(fs_info->trans_block_rsv.size > 0);
WARN_ON(fs_info->trans_block_rsv.reserved > 0);
WARN_ON(fs_info->chunk_block_rsv.size > 0);
WARN_ON(fs_info->chunk_block_rsv.reserved > 0);
WARN_ON(fs_info->delayed_block_rsv.size > 0);
WARN_ON(fs_info->delayed_block_rsv.reserved > 0);
}
void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
if (!trans->block_rsv)
return;
if (!trans->bytes_reserved)
return;
trace_btrfs_space_reservation(root->fs_info, "transaction",
trans->transid, trans->bytes_reserved, 0);
btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
trans->bytes_reserved = 0;
}
/*
* To be called after all the new block groups attached to the transaction
* handle have been created (btrfs_create_pending_block_groups()).
*/
void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = trans->root->fs_info;
if (!trans->chunk_bytes_reserved)
return;
WARN_ON_ONCE(!list_empty(&trans->new_bgs));
block_rsv_release_bytes(fs_info, &fs_info->chunk_block_rsv, NULL,
trans->chunk_bytes_reserved);
trans->chunk_bytes_reserved = 0;
}
/* Can only return 0 or -ENOSPC */
int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv;
/*
* We need to hold space in order to delete our orphan item once we've
* added it, so this takes the reservation so we can release it later
* when we are truly done with the orphan item.
*/
u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
trace_btrfs_space_reservation(root->fs_info, "orphan",
btrfs_ino(inode), num_bytes, 1);
return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
}
void btrfs_orphan_release_metadata(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1);
trace_btrfs_space_reservation(root->fs_info, "orphan",
btrfs_ino(inode), num_bytes, 0);
btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
}
/*
* btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
* root: the root of the parent directory
* rsv: block reservation
* items: the number of items that we need do reservation
* qgroup_reserved: used to return the reserved size in qgroup
*
* This function is used to reserve the space for snapshot/subvolume
* creation and deletion. Those operations are different with the
* common file/directory operations, they change two fs/file trees
* and root tree, the number of items that the qgroup reserves is
* different with the free space reservation. So we can not use
* the space reseravtion mechanism in start_transaction().
*/
int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
struct btrfs_block_rsv *rsv,
int items,
u64 *qgroup_reserved,
bool use_global_rsv)
{
u64 num_bytes;
int ret;
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
if (root->fs_info->quota_enabled) {
/* One for parent inode, two for dir entries */
num_bytes = 3 * root->nodesize;
ret = btrfs_qgroup_reserve(root, num_bytes);
if (ret)
return ret;
} else {
num_bytes = 0;
}
*qgroup_reserved = num_bytes;
num_bytes = btrfs_calc_trans_metadata_size(root, items);
rsv->space_info = __find_space_info(root->fs_info,
BTRFS_BLOCK_GROUP_METADATA);
ret = btrfs_block_rsv_add(root, rsv, num_bytes,
BTRFS_RESERVE_FLUSH_ALL);
if (ret == -ENOSPC && use_global_rsv)
ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes);
if (ret) {
if (*qgroup_reserved)
btrfs_qgroup_free(root, *qgroup_reserved);
}
return ret;
}
void btrfs_subvolume_release_metadata(struct btrfs_root *root,
struct btrfs_block_rsv *rsv,
u64 qgroup_reserved)
{
btrfs_block_rsv_release(root, rsv, (u64)-1);
}
/**
* drop_outstanding_extent - drop an outstanding extent
* @inode: the inode we're dropping the extent for
* @num_bytes: the number of bytes we're relaseing.
*
* This is called when we are freeing up an outstanding extent, either called
* after an error or after an extent is written. This will return the number of
* reserved extents that need to be freed. This must be called with
* BTRFS_I(inode)->lock held.
*/
static unsigned drop_outstanding_extent(struct inode *inode, u64 num_bytes)
{
unsigned drop_inode_space = 0;
unsigned dropped_extents = 0;
unsigned num_extents = 0;
num_extents = (unsigned)div64_u64(num_bytes +
BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
ASSERT(num_extents);
ASSERT(BTRFS_I(inode)->outstanding_extents >= num_extents);
BTRFS_I(inode)->outstanding_extents -= num_extents;
if (BTRFS_I(inode)->outstanding_extents == 0 &&
test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
&BTRFS_I(inode)->runtime_flags))
drop_inode_space = 1;
/*
* If we have more or the same amount of outsanding extents than we have
* reserved then we need to leave the reserved extents count alone.
*/
if (BTRFS_I(inode)->outstanding_extents >=
BTRFS_I(inode)->reserved_extents)
return drop_inode_space;
dropped_extents = BTRFS_I(inode)->reserved_extents -
BTRFS_I(inode)->outstanding_extents;
BTRFS_I(inode)->reserved_extents -= dropped_extents;
return dropped_extents + drop_inode_space;
}
/**
* calc_csum_metadata_size - return the amount of metada space that must be
* reserved/free'd for the given bytes.
* @inode: the inode we're manipulating
* @num_bytes: the number of bytes in question
* @reserve: 1 if we are reserving space, 0 if we are freeing space
*
* This adjusts the number of csum_bytes in the inode and then returns the
* correct amount of metadata that must either be reserved or freed. We
* calculate how many checksums we can fit into one leaf and then divide the
* number of bytes that will need to be checksumed by this value to figure out
* how many checksums will be required. If we are adding bytes then the number
* may go up and we will return the number of additional bytes that must be
* reserved. If it is going down we will return the number of bytes that must
* be freed.
*
* This must be called with BTRFS_I(inode)->lock held.
*/
static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes,
int reserve)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 old_csums, num_csums;
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM &&
BTRFS_I(inode)->csum_bytes == 0)
return 0;
old_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
if (reserve)
BTRFS_I(inode)->csum_bytes += num_bytes;
else
BTRFS_I(inode)->csum_bytes -= num_bytes;
num_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes);
/* No change, no need to reserve more */
if (old_csums == num_csums)
return 0;
if (reserve)
return btrfs_calc_trans_metadata_size(root,
num_csums - old_csums);
return btrfs_calc_trans_metadata_size(root, old_csums - num_csums);
}
int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv;
u64 to_reserve = 0;
u64 csum_bytes;
unsigned nr_extents = 0;
int extra_reserve = 0;
enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL;
int ret = 0;
bool delalloc_lock = true;
u64 to_free = 0;
unsigned dropped;
/* If we are a free space inode we need to not flush since we will be in
* the middle of a transaction commit. We also don't need the delalloc
* mutex since we won't race with anybody. We need this mostly to make
* lockdep shut its filthy mouth.
*/
if (btrfs_is_free_space_inode(inode)) {
flush = BTRFS_RESERVE_NO_FLUSH;
delalloc_lock = false;
}
if (flush != BTRFS_RESERVE_NO_FLUSH &&
btrfs_transaction_in_commit(root->fs_info))
schedule_timeout(1);
if (delalloc_lock)
mutex_lock(&BTRFS_I(inode)->delalloc_mutex);
num_bytes = ALIGN(num_bytes, root->sectorsize);
spin_lock(&BTRFS_I(inode)->lock);
nr_extents = (unsigned)div64_u64(num_bytes +
BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
BTRFS_I(inode)->outstanding_extents += nr_extents;
nr_extents = 0;
if (BTRFS_I(inode)->outstanding_extents >
BTRFS_I(inode)->reserved_extents)
nr_extents = BTRFS_I(inode)->outstanding_extents -
BTRFS_I(inode)->reserved_extents;
/*
* Add an item to reserve for updating the inode when we complete the
* delalloc io.
*/
if (!test_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
&BTRFS_I(inode)->runtime_flags)) {
nr_extents++;
extra_reserve = 1;
}
to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents);
to_reserve += calc_csum_metadata_size(inode, num_bytes, 1);
csum_bytes = BTRFS_I(inode)->csum_bytes;
spin_unlock(&BTRFS_I(inode)->lock);
if (root->fs_info->quota_enabled) {
ret = btrfs_qgroup_reserve(root, nr_extents * root->nodesize);
if (ret)
goto out_fail;
}
ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);
if (unlikely(ret)) {
if (root->fs_info->quota_enabled)
btrfs_qgroup_free(root, nr_extents * root->nodesize);
goto out_fail;
}
spin_lock(&BTRFS_I(inode)->lock);
if (extra_reserve) {
set_bit(BTRFS_INODE_DELALLOC_META_RESERVED,
&BTRFS_I(inode)->runtime_flags);
nr_extents--;
}
BTRFS_I(inode)->reserved_extents += nr_extents;
spin_unlock(&BTRFS_I(inode)->lock);
if (delalloc_lock)
mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
if (to_reserve)
trace_btrfs_space_reservation(root->fs_info, "delalloc",
btrfs_ino(inode), to_reserve, 1);
block_rsv_add_bytes(block_rsv, to_reserve, 1);
return 0;
out_fail:
spin_lock(&BTRFS_I(inode)->lock);
dropped = drop_outstanding_extent(inode, num_bytes);
/*
* If the inodes csum_bytes is the same as the original
* csum_bytes then we know we haven't raced with any free()ers
* so we can just reduce our inodes csum bytes and carry on.
*/
if (BTRFS_I(inode)->csum_bytes == csum_bytes) {
calc_csum_metadata_size(inode, num_bytes, 0);
} else {
u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes;
u64 bytes;
/*
* This is tricky, but first we need to figure out how much we
* free'd from any free-ers that occured during this
* reservation, so we reset ->csum_bytes to the csum_bytes
* before we dropped our lock, and then call the free for the
* number of bytes that were freed while we were trying our
* reservation.
*/
bytes = csum_bytes - BTRFS_I(inode)->csum_bytes;
BTRFS_I(inode)->csum_bytes = csum_bytes;
to_free = calc_csum_metadata_size(inode, bytes, 0);
/*
* Now we need to see how much we would have freed had we not
* been making this reservation and our ->csum_bytes were not
* artificially inflated.
*/
BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes;
bytes = csum_bytes - orig_csum_bytes;
bytes = calc_csum_metadata_size(inode, bytes, 0);
/*
* Now reset ->csum_bytes to what it should be. If bytes is
* more than to_free then we would have free'd more space had we
* not had an artificially high ->csum_bytes, so we need to free
* the remainder. If bytes is the same or less then we don't
* need to do anything, the other free-ers did the correct
* thing.
*/
BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes;
if (bytes > to_free)
to_free = bytes - to_free;
else
to_free = 0;
}
spin_unlock(&BTRFS_I(inode)->lock);
if (dropped)
to_free += btrfs_calc_trans_metadata_size(root, dropped);
if (to_free) {
btrfs_block_rsv_release(root, block_rsv, to_free);
trace_btrfs_space_reservation(root->fs_info, "delalloc",
btrfs_ino(inode), to_free, 0);
}
if (delalloc_lock)
mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
return ret;
}
/**
* btrfs_delalloc_release_metadata - release a metadata reservation for an inode
* @inode: the inode to release the reservation for
* @num_bytes: the number of bytes we're releasing
*
* This will release the metadata reservation for an inode. This can be called
* once we complete IO for a given set of bytes to release their metadata
* reservations.
*/
void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 to_free = 0;
unsigned dropped;
num_bytes = ALIGN(num_bytes, root->sectorsize);
spin_lock(&BTRFS_I(inode)->lock);
dropped = drop_outstanding_extent(inode, num_bytes);
if (num_bytes)
to_free = calc_csum_metadata_size(inode, num_bytes, 0);
spin_unlock(&BTRFS_I(inode)->lock);
if (dropped > 0)
to_free += btrfs_calc_trans_metadata_size(root, dropped);
if (btrfs_test_is_dummy_root(root))
return;
trace_btrfs_space_reservation(root->fs_info, "delalloc",
btrfs_ino(inode), to_free, 0);
btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv,
to_free);
}
/**
* btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc
* @inode: inode we're writing to
* @num_bytes: the number of bytes we want to allocate
*
* This will do the following things
*
* o reserve space in the data space info for num_bytes
* o reserve space in the metadata space info based on number of outstanding
* extents and how much csums will be needed
* o add to the inodes ->delalloc_bytes
* o add it to the fs_info's delalloc inodes list.
*
* This will return 0 for success and -ENOSPC if there is no space left.
*/
int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes)
{
int ret;
ret = btrfs_check_data_free_space(inode, num_bytes, num_bytes);
if (ret)
return ret;
ret = btrfs_delalloc_reserve_metadata(inode, num_bytes);
if (ret) {
btrfs_free_reserved_data_space(inode, num_bytes);
return ret;
}
return 0;
}
/**
* btrfs_delalloc_release_space - release data and metadata space for delalloc
* @inode: inode we're releasing space for
* @num_bytes: the number of bytes we want to free up
*
* This must be matched with a call to btrfs_delalloc_reserve_space. This is
* called in the case that we don't need the metadata AND data reservations
* anymore. So if there is an error or we insert an inline extent.
*
* This function will release the metadata space that was not used and will
* decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
* list if there are no delalloc bytes left.
*/
void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes)
{
btrfs_delalloc_release_metadata(inode, num_bytes);
btrfs_free_reserved_data_space(inode, num_bytes);
}
static int update_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr,
u64 num_bytes, int alloc)
{
struct btrfs_block_group_cache *cache = NULL;
struct btrfs_fs_info *info = root->fs_info;
u64 total = num_bytes;
u64 old_val;
u64 byte_in_group;
int factor;
/* block accounting for super block */
spin_lock(&info->delalloc_root_lock);
old_val = btrfs_super_bytes_used(info->super_copy);
if (alloc)
old_val += num_bytes;
else
old_val -= num_bytes;
btrfs_set_super_bytes_used(info->super_copy, old_val);
spin_unlock(&info->delalloc_root_lock);
while (total) {
cache = btrfs_lookup_block_group(info, bytenr);
if (!cache)
return -ENOENT;
if (cache->flags & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
/*
* If this block group has free space cache written out, we
* need to make sure to load it if we are removing space. This
* is because we need the unpinning stage to actually add the
* space back to the block group, otherwise we will leak space.
*/
if (!alloc && cache->cached == BTRFS_CACHE_NO)
cache_block_group(cache, 1);
byte_in_group = bytenr - cache->key.objectid;
WARN_ON(byte_in_group > cache->key.offset);
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
if (btrfs_test_opt(root, SPACE_CACHE) &&
cache->disk_cache_state < BTRFS_DC_CLEAR)
cache->disk_cache_state = BTRFS_DC_CLEAR;
old_val = btrfs_block_group_used(&cache->item);
num_bytes = min(total, cache->key.offset - byte_in_group);
if (alloc) {
old_val += num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
cache->reserved -= num_bytes;
cache->space_info->bytes_reserved -= num_bytes;
cache->space_info->bytes_used += num_bytes;
cache->space_info->disk_used += num_bytes * factor;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
} else {
old_val -= num_bytes;
btrfs_set_block_group_used(&cache->item, old_val);
cache->pinned += num_bytes;
cache->space_info->bytes_pinned += num_bytes;
cache->space_info->bytes_used -= num_bytes;
cache->space_info->disk_used -= num_bytes * factor;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
set_extent_dirty(info->pinned_extents,
bytenr, bytenr + num_bytes - 1,
GFP_NOFS | __GFP_NOFAIL);
/*
* No longer have used bytes in this block group, queue
* it for deletion.
*/
if (old_val == 0) {
spin_lock(&info->unused_bgs_lock);
if (list_empty(&cache->bg_list)) {
btrfs_get_block_group(cache);
list_add_tail(&cache->bg_list,
&info->unused_bgs);
}
spin_unlock(&info->unused_bgs_lock);
}
}
spin_lock(&trans->transaction->dirty_bgs_lock);
if (list_empty(&cache->dirty_list)) {
list_add_tail(&cache->dirty_list,
&trans->transaction->dirty_bgs);
trans->transaction->num_dirty_bgs++;
btrfs_get_block_group(cache);
}
spin_unlock(&trans->transaction->dirty_bgs_lock);
btrfs_put_block_group(cache);
total -= num_bytes;
bytenr += num_bytes;
}
return 0;
}
static u64 first_logical_byte(struct btrfs_root *root, u64 search_start)
{
struct btrfs_block_group_cache *cache;
u64 bytenr;
spin_lock(&root->fs_info->block_group_cache_lock);
bytenr = root->fs_info->first_logical_byte;
spin_unlock(&root->fs_info->block_group_cache_lock);
if (bytenr < (u64)-1)
return bytenr;
cache = btrfs_lookup_first_block_group(root->fs_info, search_start);
if (!cache)
return 0;
bytenr = cache->key.objectid;
btrfs_put_block_group(cache);
return bytenr;
}
static int pin_down_extent(struct btrfs_root *root,
struct btrfs_block_group_cache *cache,
u64 bytenr, u64 num_bytes, int reserved)
{
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->pinned += num_bytes;
cache->space_info->bytes_pinned += num_bytes;
if (reserved) {
cache->reserved -= num_bytes;
cache->space_info->bytes_reserved -= num_bytes;
}
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
set_extent_dirty(root->fs_info->pinned_extents, bytenr,
bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
if (reserved)
trace_btrfs_reserved_extent_free(root, bytenr, num_bytes);
return 0;
}
/*
* this function must be called within transaction
*/
int btrfs_pin_extent(struct btrfs_root *root,
u64 bytenr, u64 num_bytes, int reserved)
{
struct btrfs_block_group_cache *cache;
cache = btrfs_lookup_block_group(root->fs_info, bytenr);
BUG_ON(!cache); /* Logic error */
pin_down_extent(root, cache, bytenr, num_bytes, reserved);
btrfs_put_block_group(cache);
return 0;
}
/*
* this function must be called within transaction
*/
int btrfs_pin_extent_for_log_replay(struct btrfs_root *root,
u64 bytenr, u64 num_bytes)
{
struct btrfs_block_group_cache *cache;
int ret;
cache = btrfs_lookup_block_group(root->fs_info, bytenr);
if (!cache)
return -EINVAL;
/*
* pull in the free space cache (if any) so that our pin
* removes the free space from the cache. We have load_only set
* to one because the slow code to read in the free extents does check
* the pinned extents.
*/
cache_block_group(cache, 1);
pin_down_extent(root, cache, bytenr, num_bytes, 0);
/* remove us from the free space cache (if we're there at all) */
ret = btrfs_remove_free_space(cache, bytenr, num_bytes);
btrfs_put_block_group(cache);
return ret;
}
static int __exclude_logged_extent(struct btrfs_root *root, u64 start, u64 num_bytes)
{
int ret;
struct btrfs_block_group_cache *block_group;
struct btrfs_caching_control *caching_ctl;
block_group = btrfs_lookup_block_group(root->fs_info, start);
if (!block_group)
return -EINVAL;
cache_block_group(block_group, 0);
caching_ctl = get_caching_control(block_group);
if (!caching_ctl) {
/* Logic error */
BUG_ON(!block_group_cache_done(block_group));
ret = btrfs_remove_free_space(block_group, start, num_bytes);
} else {
mutex_lock(&caching_ctl->mutex);
if (start >= caching_ctl->progress) {
ret = add_excluded_extent(root, start, num_bytes);
} else if (start + num_bytes <= caching_ctl->progress) {
ret = btrfs_remove_free_space(block_group,
start, num_bytes);
} else {
num_bytes = caching_ctl->progress - start;
ret = btrfs_remove_free_space(block_group,
start, num_bytes);
if (ret)
goto out_lock;
num_bytes = (start + num_bytes) -
caching_ctl->progress;
start = caching_ctl->progress;
ret = add_excluded_extent(root, start, num_bytes);
}
out_lock:
mutex_unlock(&caching_ctl->mutex);
put_caching_control(caching_ctl);
}
btrfs_put_block_group(block_group);
return ret;
}
int btrfs_exclude_logged_extents(struct btrfs_root *log,
struct extent_buffer *eb)
{
struct btrfs_file_extent_item *item;
struct btrfs_key key;
int found_type;
int i;
if (!btrfs_fs_incompat(log->fs_info, MIXED_GROUPS))
return 0;
for (i = 0; i < btrfs_header_nritems(eb); i++) {
btrfs_item_key_to_cpu(eb, &key, i);
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(eb, item);
if (found_type == BTRFS_FILE_EXTENT_INLINE)
continue;
if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
continue;
key.objectid = btrfs_file_extent_disk_bytenr(eb, item);
key.offset = btrfs_file_extent_disk_num_bytes(eb, item);
__exclude_logged_extent(log, key.objectid, key.offset);
}
return 0;
}
/**
* btrfs_update_reserved_bytes - update the block_group and space info counters
* @cache: The cache we are manipulating
* @num_bytes: The number of bytes in question
* @reserve: One of the reservation enums
* @delalloc: The blocks are allocated for the delalloc write
*
* This is called by the allocator when it reserves space, or by somebody who is
* freeing space that was never actually used on disk. For example if you
* reserve some space for a new leaf in transaction A and before transaction A
* commits you free that leaf, you call this with reserve set to 0 in order to
* clear the reservation.
*
* Metadata reservations should be called with RESERVE_ALLOC so we do the proper
* ENOSPC accounting. For data we handle the reservation through clearing the
* delalloc bits in the io_tree. We have to do this since we could end up
* allocating less disk space for the amount of data we have reserved in the
* case of compression.
*
* If this is a reservation and the block group has become read only we cannot
* make the reservation and return -EAGAIN, otherwise this function always
* succeeds.
*/
static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache,
u64 num_bytes, int reserve, int delalloc)
{
struct btrfs_space_info *space_info = cache->space_info;
int ret = 0;
spin_lock(&space_info->lock);
spin_lock(&cache->lock);
if (reserve != RESERVE_FREE) {
if (cache->ro) {
ret = -EAGAIN;
} else {
cache->reserved += num_bytes;
space_info->bytes_reserved += num_bytes;
if (reserve == RESERVE_ALLOC) {
trace_btrfs_space_reservation(cache->fs_info,
"space_info", space_info->flags,
num_bytes, 0);
space_info->bytes_may_use -= num_bytes;
}
if (delalloc)
cache->delalloc_bytes += num_bytes;
}
} else {
if (cache->ro)
space_info->bytes_readonly += num_bytes;
cache->reserved -= num_bytes;
space_info->bytes_reserved -= num_bytes;
if (delalloc)
cache->delalloc_bytes -= num_bytes;
}
spin_unlock(&cache->lock);
spin_unlock(&space_info->lock);
return ret;
}
void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_caching_control *next;
struct btrfs_caching_control *caching_ctl;
struct btrfs_block_group_cache *cache;
down_write(&fs_info->commit_root_sem);
list_for_each_entry_safe(caching_ctl, next,
&fs_info->caching_block_groups, list) {
cache = caching_ctl->block_group;
if (block_group_cache_done(cache)) {
cache->last_byte_to_unpin = (u64)-1;
list_del_init(&caching_ctl->list);
put_caching_control(caching_ctl);
} else {
cache->last_byte_to_unpin = caching_ctl->progress;
}
}
if (fs_info->pinned_extents == &fs_info->freed_extents[0])
fs_info->pinned_extents = &fs_info->freed_extents[1];
else
fs_info->pinned_extents = &fs_info->freed_extents[0];
up_write(&fs_info->commit_root_sem);
update_global_block_rsv(fs_info);
}
static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end,
const bool return_free_space)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_group_cache *cache = NULL;
struct btrfs_space_info *space_info;
struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
u64 len;
bool readonly;
while (start <= end) {
readonly = false;
if (!cache ||
start >= cache->key.objectid + cache->key.offset) {
if (cache)
btrfs_put_block_group(cache);
cache = btrfs_lookup_block_group(fs_info, start);
BUG_ON(!cache); /* Logic error */
}
len = cache->key.objectid + cache->key.offset - start;
len = min(len, end + 1 - start);
if (start < cache->last_byte_to_unpin) {
len = min(len, cache->last_byte_to_unpin - start);
if (return_free_space)
btrfs_add_free_space(cache, start, len);
}
start += len;
space_info = cache->space_info;
spin_lock(&space_info->lock);
spin_lock(&cache->lock);
cache->pinned -= len;
space_info->bytes_pinned -= len;
percpu_counter_add(&space_info->total_bytes_pinned, -len);
if (cache->ro) {
space_info->bytes_readonly += len;
readonly = true;
}
spin_unlock(&cache->lock);
if (!readonly && global_rsv->space_info == space_info) {
spin_lock(&global_rsv->lock);
if (!global_rsv->full) {
len = min(len, global_rsv->size -
global_rsv->reserved);
global_rsv->reserved += len;
space_info->bytes_may_use += len;
if (global_rsv->reserved >= global_rsv->size)
global_rsv->full = 1;
}
spin_unlock(&global_rsv->lock);
}
spin_unlock(&space_info->lock);
}
if (cache)
btrfs_put_block_group(cache);
return 0;
}
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_group_cache *block_group, *tmp;
struct list_head *deleted_bgs;
struct extent_io_tree *unpin;
u64 start;
u64 end;
int ret;
if (fs_info->pinned_extents == &fs_info->freed_extents[0])
unpin = &fs_info->freed_extents[1];
else
unpin = &fs_info->freed_extents[0];
while (!trans->aborted) {
mutex_lock(&fs_info->unused_bg_unpin_mutex);
ret = find_first_extent_bit(unpin, 0, &start, &end,
EXTENT_DIRTY, NULL);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
break;
}
if (btrfs_test_opt(root, DISCARD))
ret = btrfs_discard_extent(root, start,
end + 1 - start, NULL);
clear_extent_dirty(unpin, start, end, GFP_NOFS);
unpin_extent_range(root, start, end, true);
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
cond_resched();
}
/*
* Transaction is finished. We don't need the lock anymore. We
* do need to clean up the block groups in case of a transaction
* abort.
*/
deleted_bgs = &trans->transaction->deleted_bgs;
list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) {
u64 trimmed = 0;
ret = -EROFS;
if (!trans->aborted)
ret = btrfs_discard_extent(root,
block_group->key.objectid,
block_group->key.offset,
&trimmed);
list_del_init(&block_group->bg_list);
btrfs_put_block_group_trimming(block_group);
btrfs_put_block_group(block_group);
if (ret) {
const char *errstr = btrfs_decode_error(ret);
btrfs_warn(fs_info,
"Discard failed while removing blockgroup: errno=%d %s\n",
ret, errstr);
}
}
return 0;
}
static void add_pinned_bytes(struct btrfs_fs_info *fs_info, u64 num_bytes,
u64 owner, u64 root_objectid)
{
struct btrfs_space_info *space_info;
u64 flags;
if (owner < BTRFS_FIRST_FREE_OBJECTID) {
if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID)
flags = BTRFS_BLOCK_GROUP_SYSTEM;
else
flags = BTRFS_BLOCK_GROUP_METADATA;
} else {
flags = BTRFS_BLOCK_GROUP_DATA;
}
space_info = __find_space_info(fs_info, flags);
BUG_ON(!space_info); /* Logic bug */
percpu_counter_add(&space_info->total_bytes_pinned, num_bytes);
}
static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_delayed_ref_node *node, u64 parent,
u64 root_objectid, u64 owner_objectid,
u64 owner_offset, int refs_to_drop,
struct btrfs_delayed_extent_op *extent_op)
{
struct btrfs_key key;
struct btrfs_path *path;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
struct btrfs_extent_item *ei;
struct btrfs_extent_inline_ref *iref;
int ret;
int is_data;
int extent_slot = 0;
int found_extent = 0;
int num_to_del = 1;
int no_quota = node->no_quota;
u32 item_size;
u64 refs;
u64 bytenr = node->bytenr;
u64 num_bytes = node->num_bytes;
int last_ref = 0;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
if (!info->quota_enabled || !is_fstree(root_objectid))
no_quota = 1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
path->leave_spinning = 1;
is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID;
BUG_ON(!is_data && refs_to_drop != 1);
if (is_data)
skinny_metadata = 0;
ret = lookup_extent_backref(trans, extent_root, path, &iref,
bytenr, num_bytes, parent,
root_objectid, owner_objectid,
owner_offset);
if (ret == 0) {
extent_slot = path->slots[0];
while (extent_slot >= 0) {
btrfs_item_key_to_cpu(path->nodes[0], &key,
extent_slot);
if (key.objectid != bytenr)
break;
if (key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == num_bytes) {
found_extent = 1;
break;
}
if (key.type == BTRFS_METADATA_ITEM_KEY &&
key.offset == owner_objectid) {
found_extent = 1;
break;
}
if (path->slots[0] - extent_slot > 5)
break;
extent_slot--;
}
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);
if (found_extent && item_size < sizeof(*ei))
found_extent = 0;
#endif
if (!found_extent) {
BUG_ON(iref);
ret = remove_extent_backref(trans, extent_root, path,
NULL, refs_to_drop,
is_data, &last_ref);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
btrfs_release_path(path);
path->leave_spinning = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
if (!is_data && skinny_metadata) {
key.type = BTRFS_METADATA_ITEM_KEY;
key.offset = owner_objectid;
}
ret = btrfs_search_slot(trans, extent_root,
&key, path, -1, 1);
if (ret > 0 && skinny_metadata && path->slots[0]) {
/*
* Couldn't find our skinny metadata item,
* see if we have ye olde extent item.
*/
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid == bytenr &&
key.type == BTRFS_EXTENT_ITEM_KEY &&
key.offset == num_bytes)
ret = 0;
}
if (ret > 0 && skinny_metadata) {
skinny_metadata = false;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
btrfs_release_path(path);
ret = btrfs_search_slot(trans, extent_root,
&key, path, -1, 1);
}
if (ret) {
btrfs_err(info, "umm, got %d back from search, was looking for %llu",
ret, bytenr);
if (ret > 0)
btrfs_print_leaf(extent_root,
path->nodes[0]);
}
if (ret < 0) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
extent_slot = path->slots[0];
}
} else if (WARN_ON(ret == -ENOENT)) {
btrfs_print_leaf(extent_root, path->nodes[0]);
btrfs_err(info,
"unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu",
bytenr, parent, root_objectid, owner_objectid,
owner_offset);
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
} else {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, extent_slot);
#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
if (item_size < sizeof(*ei)) {
BUG_ON(found_extent || extent_slot != path->slots[0]);
ret = convert_extent_item_v0(trans, extent_root, path,
owner_objectid, 0);
if (ret < 0) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
btrfs_release_path(path);
path->leave_spinning = 1;
key.objectid = bytenr;
key.type = BTRFS_EXTENT_ITEM_KEY;
key.offset = num_bytes;
ret = btrfs_search_slot(trans, extent_root, &key, path,
-1, 1);
if (ret) {
btrfs_err(info, "umm, got %d back from search, was looking for %llu",
ret, bytenr);
btrfs_print_leaf(extent_root, path->nodes[0]);
}
if (ret < 0) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
extent_slot = path->slots[0];
leaf = path->nodes[0];
item_size = btrfs_item_size_nr(leaf, extent_slot);
}
#endif
BUG_ON(item_size < sizeof(*ei));
ei = btrfs_item_ptr(leaf, extent_slot,
struct btrfs_extent_item);
if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID &&
key.type == BTRFS_EXTENT_ITEM_KEY) {
struct btrfs_tree_block_info *bi;
BUG_ON(item_size < sizeof(*ei) + sizeof(*bi));
bi = (struct btrfs_tree_block_info *)(ei + 1);
WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi));
}
refs = btrfs_extent_refs(leaf, ei);
if (refs < refs_to_drop) {
btrfs_err(info, "trying to drop %d refs but we only have %Lu "
"for bytenr %Lu", refs_to_drop, refs, bytenr);
ret = -EINVAL;
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
refs -= refs_to_drop;
if (refs > 0) {
if (extent_op)
__run_delayed_extent_op(extent_op, leaf, ei);
/*
* In the case of inline back ref, reference count will
* be updated by remove_extent_backref
*/
if (iref) {
BUG_ON(!found_extent);
} else {
btrfs_set_extent_refs(leaf, ei, refs);
btrfs_mark_buffer_dirty(leaf);
}
if (found_extent) {
ret = remove_extent_backref(trans, extent_root, path,
iref, refs_to_drop,
is_data, &last_ref);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
}
add_pinned_bytes(root->fs_info, -num_bytes, owner_objectid,
root_objectid);
} else {
if (found_extent) {
BUG_ON(is_data && refs_to_drop !=
extent_data_ref_count(path, iref));
if (iref) {
BUG_ON(path->slots[0] != extent_slot);
} else {
BUG_ON(path->slots[0] != extent_slot + 1);
path->slots[0] = extent_slot;
num_to_del = 2;
}
}
last_ref = 1;
ret = btrfs_del_items(trans, extent_root, path, path->slots[0],
num_to_del);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
btrfs_release_path(path);
if (is_data) {
ret = btrfs_del_csums(trans, root, bytenr, num_bytes);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
}
ret = update_block_group(trans, root, bytenr, num_bytes, 0);
if (ret) {
btrfs_abort_transaction(trans, extent_root, ret);
goto out;
}
}
btrfs_release_path(path);
out:
btrfs_free_path(path);
return ret;
}
/*
* when we free an block, it is possible (and likely) that we free the last
* delayed ref for that extent as well. This searches the delayed ref tree for
* a given extent, and if there are no other delayed refs to be processed, it
* removes it from the tree.
*/
static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytenr)
{
struct btrfs_delayed_ref_head *head;
struct btrfs_delayed_ref_root *delayed_refs;
int ret = 0;
delayed_refs = &trans->transaction->delayed_refs;
spin_lock(&delayed_refs->lock);
head = btrfs_find_delayed_ref_head(trans, bytenr);
if (!head)
goto out_delayed_unlock;
spin_lock(&head->lock);
if (!list_empty(&head->ref_list))
goto out;
if (head->extent_op) {
if (!head->must_insert_reserved)
goto out;
btrfs_free_delayed_extent_op(head->extent_op);
head->extent_op = NULL;
}
/*
* waiting for the lock here would deadlock. If someone else has it
* locked they are already in the process of dropping it anyway
*/
if (!mutex_trylock(&head->mutex))
goto out;
/*
* at this point we have a head with no other entries. Go
* ahead and process it.
*/
head->node.in_tree = 0;
rb_erase(&head->href_node, &delayed_refs->href_root);
atomic_dec(&delayed_refs->num_entries);
/*
* we don't take a ref on the node because we're removing it from the
* tree, so we just steal the ref the tree was holding.
*/
delayed_refs->num_heads--;
if (head->processing == 0)
delayed_refs->num_heads_ready--;
head->processing = 0;
spin_unlock(&head->lock);
spin_unlock(&delayed_refs->lock);
BUG_ON(head->extent_op);
if (head->must_insert_reserved)
ret = 1;
mutex_unlock(&head->mutex);
btrfs_put_delayed_ref(&head->node);
return ret;
out:
spin_unlock(&head->lock);
out_delayed_unlock:
spin_unlock(&delayed_refs->lock);
return 0;
}
void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *buf,
u64 parent, int last_ref)
{
int pin = 1;
int ret;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
buf->start, buf->len,
parent, root->root_key.objectid,
btrfs_header_level(buf),
BTRFS_DROP_DELAYED_REF, NULL, 0);
BUG_ON(ret); /* -ENOMEM */
}
if (!last_ref)
return;
if (btrfs_header_generation(buf) == trans->transid) {
struct btrfs_block_group_cache *cache;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
ret = check_ref_cleanup(trans, root, buf->start);
if (!ret)
goto out;
}
cache = btrfs_lookup_block_group(root->fs_info, buf->start);
if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
pin_down_extent(root, cache, buf->start, buf->len, 1);
btrfs_put_block_group(cache);
goto out;
}
WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags));
btrfs_add_free_space(cache, buf->start, buf->len);
btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE, 0);
btrfs_put_block_group(cache);
trace_btrfs_reserved_extent_free(root, buf->start, buf->len);
pin = 0;
}
out:
if (pin)
add_pinned_bytes(root->fs_info, buf->len,
btrfs_header_level(buf),
root->root_key.objectid);
/*
* Deleting the buffer, clear the corrupt flag since it doesn't matter
* anymore.
*/
clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags);
}
/* Can return -ENOMEM */
int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid,
u64 owner, u64 offset, int no_quota)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
if (btrfs_test_is_dummy_root(root))
return 0;
add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid);
/*
* tree log blocks never actually go into the extent allocation
* tree, just update pinning info and exit early.
*/
if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
/* unlocks the pinned mutex */
btrfs_pin_extent(root, bytenr, num_bytes, 1);
ret = 0;
} else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr,
num_bytes,
parent, root_objectid, (int)owner,
BTRFS_DROP_DELAYED_REF, NULL, no_quota);
} else {
ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr,
num_bytes,
parent, root_objectid, owner,
offset, BTRFS_DROP_DELAYED_REF,
NULL, no_quota);
}
return ret;
}
/*
* when we wait for progress in the block group caching, its because
* our allocation attempt failed at least once. So, we must sleep
* and let some progress happen before we try again.
*
* This function will sleep at least once waiting for new free space to
* show up, and then it will check the block group free space numbers
* for our min num_bytes. Another option is to have it go ahead
* and look in the rbtree for a free extent of a given size, but this
* is a good start.
*
* Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using
* any of the information in this block group.
*/
static noinline void
wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
u64 num_bytes)
{
struct btrfs_caching_control *caching_ctl;
caching_ctl = get_caching_control(cache);
if (!caching_ctl)
return;
wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
(cache->free_space_ctl->free_space >= num_bytes));
put_caching_control(caching_ctl);
}
static noinline int
wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
{
struct btrfs_caching_control *caching_ctl;
int ret = 0;
caching_ctl = get_caching_control(cache);
if (!caching_ctl)
return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
wait_event(caching_ctl->wait, block_group_cache_done(cache));
if (cache->cached == BTRFS_CACHE_ERROR)
ret = -EIO;
put_caching_control(caching_ctl);
return ret;
}
int __get_raid_index(u64 flags)
{
if (flags & BTRFS_BLOCK_GROUP_RAID10)
return BTRFS_RAID_RAID10;
else if (flags & BTRFS_BLOCK_GROUP_RAID1)
return BTRFS_RAID_RAID1;
else if (flags & BTRFS_BLOCK_GROUP_DUP)
return BTRFS_RAID_DUP;
else if (flags & BTRFS_BLOCK_GROUP_RAID0)
return BTRFS_RAID_RAID0;
else if (flags & BTRFS_BLOCK_GROUP_RAID5)
return BTRFS_RAID_RAID5;
else if (flags & BTRFS_BLOCK_GROUP_RAID6)
return BTRFS_RAID_RAID6;
return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
}
int get_block_group_index(struct btrfs_block_group_cache *cache)
{
return __get_raid_index(cache->flags);
}
static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = {
[BTRFS_RAID_RAID10] = "raid10",
[BTRFS_RAID_RAID1] = "raid1",
[BTRFS_RAID_DUP] = "dup",
[BTRFS_RAID_RAID0] = "raid0",
[BTRFS_RAID_SINGLE] = "single",
[BTRFS_RAID_RAID5] = "raid5",
[BTRFS_RAID_RAID6] = "raid6",
};
static const char *get_raid_name(enum btrfs_raid_types type)
{
if (type >= BTRFS_NR_RAID_TYPES)
return NULL;
return btrfs_raid_type_names[type];
}
enum btrfs_loop_type {
LOOP_CACHING_NOWAIT = 0,
LOOP_CACHING_WAIT = 1,
LOOP_ALLOC_CHUNK = 2,
LOOP_NO_EMPTY_SIZE = 3,
};
static inline void
btrfs_lock_block_group(struct btrfs_block_group_cache *cache,
int delalloc)
{
if (delalloc)
down_read(&cache->data_rwsem);
}
static inline void
btrfs_grab_block_group(struct btrfs_block_group_cache *cache,
int delalloc)
{
btrfs_get_block_group(cache);
if (delalloc)
down_read(&cache->data_rwsem);
}
static struct btrfs_block_group_cache *
btrfs_lock_cluster(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
int delalloc)
{
struct btrfs_block_group_cache *used_bg;
bool locked = false;
again:
spin_lock(&cluster->refill_lock);
if (locked) {
if (used_bg == cluster->block_group)
return used_bg;
up_read(&used_bg->data_rwsem);
btrfs_put_block_group(used_bg);
}
used_bg = cluster->block_group;
if (!used_bg)
return NULL;
if (used_bg == block_group)
return used_bg;
btrfs_get_block_group(used_bg);
if (!delalloc)
return used_bg;
if (down_read_trylock(&used_bg->data_rwsem))
return used_bg;
spin_unlock(&cluster->refill_lock);
down_read(&used_bg->data_rwsem);
locked = true;
goto again;
}
static inline void
btrfs_release_block_group(struct btrfs_block_group_cache *cache,
int delalloc)
{
if (delalloc)
up_read(&cache->data_rwsem);
btrfs_put_block_group(cache);
}
/*
* walks the btree of allocated extents and find a hole of a given size.
* The key ins is changed to record the hole:
* ins->objectid == start position
* ins->flags = BTRFS_EXTENT_ITEM_KEY
* ins->offset == the size of the hole.
* Any available blocks before search_start are skipped.
*
* If there is no suitable free space, we will record the max size of
* the free space extent currently.
*/
static noinline int find_free_extent(struct btrfs_root *orig_root,
u64 num_bytes, u64 empty_size,
u64 hint_byte, struct btrfs_key *ins,
u64 flags, int delalloc)
{
int ret = 0;
struct btrfs_root *root = orig_root->fs_info->extent_root;
struct btrfs_free_cluster *last_ptr = NULL;
struct btrfs_block_group_cache *block_group = NULL;
u64 search_start = 0;
u64 max_extent_size = 0;
int empty_cluster = 2 * 1024 * 1024;
struct btrfs_space_info *space_info;
int loop = 0;
int index = __get_raid_index(flags);
int alloc_type = (flags & BTRFS_BLOCK_GROUP_DATA) ?
RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC;
bool failed_cluster_refill = false;
bool failed_alloc = false;
bool use_cluster = true;
bool have_caching_bg = false;
WARN_ON(num_bytes < root->sectorsize);
ins->type = BTRFS_EXTENT_ITEM_KEY;
ins->objectid = 0;
ins->offset = 0;
trace_find_free_extent(orig_root, num_bytes, empty_size, flags);
space_info = __find_space_info(root->fs_info, flags);
if (!space_info) {
btrfs_err(root->fs_info, "No space info for %llu", flags);
return -ENOSPC;
}
/*
* If the space info is for both data and metadata it means we have a
* small filesystem and we can't use the clustering stuff.
*/
if (btrfs_mixed_space_info(space_info))
use_cluster = false;
if (flags & BTRFS_BLOCK_GROUP_METADATA && use_cluster) {
last_ptr = &root->fs_info->meta_alloc_cluster;
if (!btrfs_test_opt(root, SSD))
empty_cluster = 64 * 1024;
}
if ((flags & BTRFS_BLOCK_GROUP_DATA) && use_cluster &&
btrfs_test_opt(root, SSD)) {
last_ptr = &root->fs_info->data_alloc_cluster;
}
if (last_ptr) {
spin_lock(&last_ptr->lock);
if (last_ptr->block_group)
hint_byte = last_ptr->window_start;
spin_unlock(&last_ptr->lock);
}
search_start = max(search_start, first_logical_byte(root, 0));
search_start = max(search_start, hint_byte);
if (!last_ptr)
empty_cluster = 0;
if (search_start == hint_byte) {
block_group = btrfs_lookup_block_group(root->fs_info,
search_start);
/*
* we don't want to use the block group if it doesn't match our
* allocation bits, or if its not cached.
*
* However if we are re-searching with an ideal block group
* picked out then we don't care that the block group is cached.
*/
if (block_group && block_group_bits(block_group, flags) &&
block_group->cached != BTRFS_CACHE_NO) {
down_read(&space_info->groups_sem);
if (list_empty(&block_group->list) ||
block_group->ro) {
/*
* someone is removing this block group,
* we can't jump into the have_block_group
* target because our list pointers are not
* valid
*/
btrfs_put_block_group(block_group);
up_read(&space_info->groups_sem);
} else {
index = get_block_group_index(block_group);
btrfs_lock_block_group(block_group, delalloc);
goto have_block_group;
}
} else if (block_group) {
btrfs_put_block_group(block_group);
}
}
search:
have_caching_bg = false;
down_read(&space_info->groups_sem);
list_for_each_entry(block_group, &space_info->block_groups[index],
list) {
u64 offset;
int cached;
btrfs_grab_block_group(block_group, delalloc);
search_start = block_group->key.objectid;
/*
* this can happen if we end up cycling through all the
* raid types, but we want to make sure we only allocate
* for the proper type.
*/
if (!block_group_bits(block_group, flags)) {
u64 extra = BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6 |
BTRFS_BLOCK_GROUP_RAID10;
/*
* if they asked for extra copies and this block group
* doesn't provide them, bail. This does allow us to
* fill raid0 from raid1.
*/
if ((flags & extra) && !(block_group->flags & extra))
goto loop;
}
have_block_group:
cached = block_group_cache_done(block_group);
if (unlikely(!cached)) {
ret = cache_block_group(block_group, 0);
BUG_ON(ret < 0);
ret = 0;
}
if (unlikely(block_group->cached == BTRFS_CACHE_ERROR))
goto loop;
if (unlikely(block_group->ro))
goto loop;
/*
* Ok we want to try and use the cluster allocator, so
* lets look there
*/
if (last_ptr) {
struct btrfs_block_group_cache *used_block_group;
unsigned long aligned_cluster;
/*
* the refill lock keeps out other
* people trying to start a new cluster
*/
used_block_group = btrfs_lock_cluster(block_group,
last_ptr,
delalloc);
if (!used_block_group)
goto refill_cluster;
if (used_block_group != block_group &&
(used_block_group->ro ||
!block_group_bits(used_block_group, flags)))
goto release_cluster;
offset = btrfs_alloc_from_cluster(used_block_group,
last_ptr,
num_bytes,
used_block_group->key.objectid,
&max_extent_size);
if (offset) {
/* we have a block, we're done */
spin_unlock(&last_ptr->refill_lock);
trace_btrfs_reserve_extent_cluster(root,
used_block_group,
search_start, num_bytes);
if (used_block_group != block_group) {
btrfs_release_block_group(block_group,
delalloc);
block_group = used_block_group;
}
goto checks;
}
WARN_ON(last_ptr->block_group != used_block_group);
release_cluster:
/* If we are on LOOP_NO_EMPTY_SIZE, we can't
* set up a new clusters, so lets just skip it
* and let the allocator find whatever block
* it can find. If we reach this point, we
* will have tried the cluster allocator
* plenty of times and not have found
* anything, so we are likely way too
* fragmented for the clustering stuff to find
* anything.
*
* However, if the cluster is taken from the
* current block group, release the cluster
* first, so that we stand a better chance of
* succeeding in the unclustered
* allocation. */
if (loop >= LOOP_NO_EMPTY_SIZE &&
used_block_group != block_group) {
spin_unlock(&last_ptr->refill_lock);
btrfs_release_block_group(used_block_group,
delalloc);
goto unclustered_alloc;
}
/*
* this cluster didn't work out, free it and
* start over
*/
btrfs_return_cluster_to_free_space(NULL, last_ptr);
if (used_block_group != block_group)
btrfs_release_block_group(used_block_group,
delalloc);
refill_cluster:
if (loop >= LOOP_NO_EMPTY_SIZE) {
spin_unlock(&last_ptr->refill_lock);
goto unclustered_alloc;
}
aligned_cluster = max_t(unsigned long,
empty_cluster + empty_size,
block_group->full_stripe_len);
/* allocate a cluster in this block group */
ret = btrfs_find_space_cluster(root, block_group,
last_ptr, search_start,
num_bytes,
aligned_cluster);
if (ret == 0) {
/*
* now pull our allocation out of this
* cluster
*/
offset = btrfs_alloc_from_cluster(block_group,
last_ptr,
num_bytes,
search_start,
&max_extent_size);
if (offset) {
/* we found one, proceed */
spin_unlock(&last_ptr->refill_lock);
trace_btrfs_reserve_extent_cluster(root,
block_group, search_start,
num_bytes);
goto checks;
}
} else if (!cached && loop > LOOP_CACHING_NOWAIT
&& !failed_cluster_refill) {
spin_unlock(&last_ptr->refill_lock);
failed_cluster_refill = true;
wait_block_group_cache_progress(block_group,
num_bytes + empty_cluster + empty_size);
goto have_block_group;
}
/*
* at this point we either didn't find a cluster
* or we weren't able to allocate a block from our
* cluster. Free the cluster we've been trying
* to use, and go to the next block group
*/
btrfs_return_cluster_to_free_space(NULL, last_ptr);
spin_unlock(&last_ptr->refill_lock);
goto loop;
}
unclustered_alloc:
spin_lock(&block_group->free_space_ctl->tree_lock);
if (cached &&
block_group->free_space_ctl->free_space <
num_bytes + empty_cluster + empty_size) {
if (block_group->free_space_ctl->free_space >
max_extent_size)
max_extent_size =
block_group->free_space_ctl->free_space;
spin_unlock(&block_group->free_space_ctl->tree_lock);
goto loop;
}
spin_unlock(&block_group->free_space_ctl->tree_lock);
offset = btrfs_find_space_for_alloc(block_group, search_start,
num_bytes, empty_size,
&max_extent_size);
/*
* If we didn't find a chunk, and we haven't failed on this
* block group before, and this block group is in the middle of
* caching and we are ok with waiting, then go ahead and wait
* for progress to be made, and set failed_alloc to true.
*
* If failed_alloc is true then we've already waited on this
* block group once and should move on to the next block group.
*/
if (!offset && !failed_alloc && !cached &&
loop > LOOP_CACHING_NOWAIT) {
wait_block_group_cache_progress(block_group,
num_bytes + empty_size);
failed_alloc = true;
goto have_block_group;
} else if (!offset) {
if (!cached)
have_caching_bg = true;
goto loop;
}
checks:
search_start = ALIGN(offset, root->stripesize);
/* move on to the next group */
if (search_start + num_bytes >
block_group->key.objectid + block_group->key.offset) {
btrfs_add_free_space(block_group, offset, num_bytes);
goto loop;
}
if (offset < search_start)
btrfs_add_free_space(block_group, offset,
search_start - offset);
BUG_ON(offset > search_start);
ret = btrfs_update_reserved_bytes(block_group, num_bytes,
alloc_type, delalloc);
if (ret == -EAGAIN) {
btrfs_add_free_space(block_group, offset, num_bytes);
goto loop;
}
/* we are all good, lets return */
ins->objectid = search_start;
ins->offset = num_bytes;
trace_btrfs_reserve_extent(orig_root, block_group,
search_start, num_bytes);
btrfs_release_block_group(block_group, delalloc);
break;
loop:
failed_cluster_refill = false;
failed_alloc = false;
BUG_ON(index != get_block_group_index(block_group));
btrfs_release_block_group(block_group, delalloc);
}
up_read(&space_info->groups_sem);
if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg)
goto search;
if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES)
goto search;
/*
* LOOP_CACHING_NOWAIT, search partially cached block groups, kicking
* caching kthreads as we move along
* LOOP_CACHING_WAIT, search everything, and wait if our bg is caching
* LOOP_ALLOC_CHUNK, force a chunk allocation and try again
* LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try
* again
*/
if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) {
index = 0;
loop++;
if (loop == LOOP_ALLOC_CHUNK) {
struct btrfs_trans_handle *trans;
int exist = 0;
trans = current->journal_info;
if (trans)
exist = 1;
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
ret = do_chunk_alloc(trans, root, flags,
CHUNK_ALLOC_FORCE);
/*
* Do not bail out on ENOSPC since we
* can do more things.
*/
if (ret < 0 && ret != -ENOSPC)
btrfs_abort_transaction(trans,
root, ret);
else
ret = 0;
if (!exist)
btrfs_end_transaction(trans, root);
if (ret)
goto out;
}
if (loop == LOOP_NO_EMPTY_SIZE) {
empty_size = 0;
empty_cluster = 0;
}
goto search;
} else if (!ins->objectid) {
ret = -ENOSPC;
} else if (ins->objectid) {
ret = 0;
}
out:
if (ret == -ENOSPC)
ins->offset = max_extent_size;
return ret;
}
static void dump_space_info(struct btrfs_space_info *info, u64 bytes,
int dump_block_groups)
{
struct btrfs_block_group_cache *cache;
int index = 0;
spin_lock(&info->lock);
printk(KERN_INFO "BTRFS: space_info %llu has %llu free, is %sfull\n",
info->flags,
info->total_bytes - info->bytes_used - info->bytes_pinned -
info->bytes_reserved - info->bytes_readonly,
(info->full) ? "" : "not ");
printk(KERN_INFO "BTRFS: space_info total=%llu, used=%llu, pinned=%llu, "
"reserved=%llu, may_use=%llu, readonly=%llu\n",
info->total_bytes, info->bytes_used, info->bytes_pinned,
info->bytes_reserved, info->bytes_may_use,
info->bytes_readonly);
spin_unlock(&info->lock);
if (!dump_block_groups)
return;
down_read(&info->groups_sem);
again:
list_for_each_entry(cache, &info->block_groups[index], list) {
spin_lock(&cache->lock);
printk(KERN_INFO "BTRFS: "
"block group %llu has %llu bytes, "
"%llu used %llu pinned %llu reserved %s\n",
cache->key.objectid, cache->key.offset,
btrfs_block_group_used(&cache->item), cache->pinned,
cache->reserved, cache->ro ? "[readonly]" : "");
btrfs_dump_free_space(cache, bytes);
spin_unlock(&cache->lock);
}
if (++index < BTRFS_NR_RAID_TYPES)
goto again;
up_read(&info->groups_sem);
}
int btrfs_reserve_extent(struct btrfs_root *root,
u64 num_bytes, u64 min_alloc_size,
u64 empty_size, u64 hint_byte,
struct btrfs_key *ins, int is_data, int delalloc)
{
bool final_tried = false;
u64 flags;
int ret;
flags = btrfs_get_alloc_profile(root, is_data);
again:
WARN_ON(num_bytes < root->sectorsize);
ret = find_free_extent(root, num_bytes, empty_size, hint_byte, ins,
flags, delalloc);
if (ret == -ENOSPC) {
if (!final_tried && ins->offset) {
num_bytes = min(num_bytes >> 1, ins->offset);
num_bytes = round_down(num_bytes, root->sectorsize);
num_bytes = max(num_bytes, min_alloc_size);
if (num_bytes == min_alloc_size)
final_tried = true;
goto again;
} else if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
struct btrfs_space_info *sinfo;
sinfo = __find_space_info(root->fs_info, flags);
btrfs_err(root->fs_info, "allocation failed flags %llu, wanted %llu",
flags, num_bytes);
if (sinfo)
dump_space_info(sinfo, num_bytes, 1);
}
}
return ret;
}
static int __btrfs_free_reserved_extent(struct btrfs_root *root,
u64 start, u64 len,
int pin, int delalloc)
{
struct btrfs_block_group_cache *cache;
int ret = 0;
cache = btrfs_lookup_block_group(root->fs_info, start);
if (!cache) {
btrfs_err(root->fs_info, "Unable to find block group for %llu",
start);
return -ENOSPC;
}
if (pin)
pin_down_extent(root, cache, start, len, 1);
else {
if (btrfs_test_opt(root, DISCARD))
ret = btrfs_discard_extent(root, start, len, NULL);
btrfs_add_free_space(cache, start, len);
btrfs_update_reserved_bytes(cache, len, RESERVE_FREE, delalloc);
}
btrfs_put_block_group(cache);
trace_btrfs_reserved_extent_free(root, start, len);
return ret;
}
int btrfs_free_reserved_extent(struct btrfs_root *root,
u64 start, u64 len, int delalloc)
{
return __btrfs_free_reserved_extent(root, start, len, 0, delalloc);
}
int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
u64 start, u64 len)
{
return __btrfs_free_reserved_extent(root, start, len, 1, 0);
}
static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, u64 owner, u64 offset,
struct btrfs_key *ins, int ref_mod)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_extent_item *extent_item;
struct btrfs_extent_inline_ref *iref;
struct btrfs_path *path;
struct extent_buffer *leaf;
int type;
u32 size;
if (parent > 0)
type = BTRFS_SHARED_DATA_REF_KEY;
else
type = BTRFS_EXTENT_DATA_REF_KEY;
size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
ins, size);
if (ret) {
btrfs_free_path(path);
return ret;
}
leaf = path->nodes[0];
extent_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, extent_item, ref_mod);
btrfs_set_extent_generation(leaf, extent_item, trans->transid);
btrfs_set_extent_flags(leaf, extent_item,
flags | BTRFS_EXTENT_FLAG_DATA);
iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
btrfs_set_extent_inline_ref_type(leaf, iref, type);
if (parent > 0) {
struct btrfs_shared_data_ref *ref;
ref = (struct btrfs_shared_data_ref *)(iref + 1);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
btrfs_set_shared_data_ref_count(leaf, ref, ref_mod);
} else {
struct btrfs_extent_data_ref *ref;
ref = (struct btrfs_extent_data_ref *)(&iref->offset);
btrfs_set_extent_data_ref_root(leaf, ref, root_objectid);
btrfs_set_extent_data_ref_objectid(leaf, ref, owner);
btrfs_set_extent_data_ref_offset(leaf, ref, offset);
btrfs_set_extent_data_ref_count(leaf, ref, ref_mod);
}
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
ret = update_block_group(trans, root, ins->objectid, ins->offset, 1);
if (ret) { /* -ENOENT, logic error */
btrfs_err(fs_info, "update block group failed for %llu %llu",
ins->objectid, ins->offset);
BUG();
}
trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset);
return ret;
}
static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 flags, struct btrfs_disk_key *key,
int level, struct btrfs_key *ins,
int no_quota)
{
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_extent_item *extent_item;
struct btrfs_tree_block_info *block_info;
struct btrfs_extent_inline_ref *iref;
struct btrfs_path *path;
struct extent_buffer *leaf;
u32 size = sizeof(*extent_item) + sizeof(*iref);
u64 num_bytes = ins->offset;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
if (!skinny_metadata)
size += sizeof(*block_info);
path = btrfs_alloc_path();
if (!path) {
btrfs_free_and_pin_reserved_extent(root, ins->objectid,
root->nodesize);
return -ENOMEM;
}
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path,
ins, size);
if (ret) {
btrfs_free_path(path);
btrfs_free_and_pin_reserved_extent(root, ins->objectid,
root->nodesize);
return ret;
}
leaf = path->nodes[0];
extent_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, extent_item, 1);
btrfs_set_extent_generation(leaf, extent_item, trans->transid);
btrfs_set_extent_flags(leaf, extent_item,
flags | BTRFS_EXTENT_FLAG_TREE_BLOCK);
if (skinny_metadata) {
iref = (struct btrfs_extent_inline_ref *)(extent_item + 1);
num_bytes = root->nodesize;
} else {
block_info = (struct btrfs_tree_block_info *)(extent_item + 1);
btrfs_set_tree_block_key(leaf, block_info, key);
btrfs_set_tree_block_level(leaf, block_info, level);
iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
}
if (parent > 0) {
BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
btrfs_set_extent_inline_ref_type(leaf, iref,
BTRFS_SHARED_BLOCK_REF_KEY);
btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
} else {
btrfs_set_extent_inline_ref_type(leaf, iref,
BTRFS_TREE_BLOCK_REF_KEY);
btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
ret = update_block_group(trans, root, ins->objectid, root->nodesize,
1);
if (ret) { /* -ENOENT, logic error */
btrfs_err(fs_info, "update block group failed for %llu %llu",
ins->objectid, ins->offset);
BUG();
}
trace_btrfs_reserved_extent_alloc(root, ins->objectid, root->nodesize);
return ret;
}
int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 root_objectid, u64 owner,
u64 offset, struct btrfs_key *ins)
{
int ret;
BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID);
ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid,
ins->offset, 0,
root_objectid, owner, offset,
BTRFS_ADD_DELAYED_EXTENT, NULL, 0);
return ret;
}
/*
* this is used by the tree logging recovery code. It records that
* an extent has been allocated and makes sure to clear the free
* space cache bits as well
*/
int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 root_objectid, u64 owner, u64 offset,
struct btrfs_key *ins)
{
int ret;
struct btrfs_block_group_cache *block_group;
/*
* Mixed block groups will exclude before processing the log so we only
* need to do the exlude dance if this fs isn't mixed.
*/
if (!btrfs_fs_incompat(root->fs_info, MIXED_GROUPS)) {
ret = __exclude_logged_extent(root, ins->objectid, ins->offset);
if (ret)
return ret;
}
block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
if (!block_group)
return -EINVAL;
ret = btrfs_update_reserved_bytes(block_group, ins->offset,
RESERVE_ALLOC_NO_ACCOUNT, 0);
BUG_ON(ret); /* logic error */
ret = alloc_reserved_file_extent(trans, root, 0, root_objectid,
0, owner, offset, ins, 1);
btrfs_put_block_group(block_group);
return ret;
}
static struct extent_buffer *
btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
u64 bytenr, int level)
{
struct extent_buffer *buf;
buf = btrfs_find_create_tree_block(root, bytenr);
if (!buf)
return ERR_PTR(-ENOMEM);
btrfs_set_header_generation(buf, trans->transid);
btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
btrfs_tree_lock(buf);
clean_tree_block(trans, root->fs_info, buf);
clear_bit(EXTENT_BUFFER_STALE, &buf->bflags);
btrfs_set_lock_blocking(buf);
btrfs_set_buffer_uptodate(buf);
if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
buf->log_index = root->log_transid % 2;
/*
* we allow two log transactions at a time, use different
* EXENT bit to differentiate dirty pages.
*/
if (buf->log_index == 0)
set_extent_dirty(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
else
set_extent_new(&root->dirty_log_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
} else {
buf->log_index = -1;
set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
buf->start + buf->len - 1, GFP_NOFS);
}
trans->blocks_used++;
/* this returns a buffer locked for blocking */
return buf;
}
static struct btrfs_block_rsv *
use_block_rsv(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u32 blocksize)
{
struct btrfs_block_rsv *block_rsv;
struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv;
int ret;
bool global_updated = false;
block_rsv = get_block_rsv(trans, root);
if (unlikely(block_rsv->size == 0))
goto try_reserve;
again:
ret = block_rsv_use_bytes(block_rsv, blocksize);
if (!ret)
return block_rsv;
if (block_rsv->failfast)
return ERR_PTR(ret);
if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) {
global_updated = true;
update_global_block_rsv(root->fs_info);
goto again;
}
if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
static DEFINE_RATELIMIT_STATE(_rs,
DEFAULT_RATELIMIT_INTERVAL * 10,
/*DEFAULT_RATELIMIT_BURST*/ 1);
if (__ratelimit(&_rs))
WARN(1, KERN_DEBUG
"BTRFS: block rsv returned %d\n", ret);
}
try_reserve:
ret = reserve_metadata_bytes(root, block_rsv, blocksize,
BTRFS_RESERVE_NO_FLUSH);
if (!ret)
return block_rsv;
/*
* If we couldn't reserve metadata bytes try and use some from
* the global reserve if its space type is the same as the global
* reservation.
*/
if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL &&
block_rsv->space_info == global_rsv->space_info) {
ret = block_rsv_use_bytes(global_rsv, blocksize);
if (!ret)
return global_rsv;
}
return ERR_PTR(ret);
}
static void unuse_block_rsv(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *block_rsv, u32 blocksize)
{
block_rsv_add_bytes(block_rsv, blocksize, 0);
block_rsv_release_bytes(fs_info, block_rsv, NULL, 0);
}
/*
* finds a free extent and does all the dirty work required for allocation
* returns the tree buffer or an ERR_PTR on error.
*/
struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
struct btrfs_disk_key *key, int level,
u64 hint, u64 empty_size)
{
struct btrfs_key ins;
struct btrfs_block_rsv *block_rsv;
struct extent_buffer *buf;
struct btrfs_delayed_extent_op *extent_op;
u64 flags = 0;
int ret;
u32 blocksize = root->nodesize;
bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
SKINNY_METADATA);
if (btrfs_test_is_dummy_root(root)) {
buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr,
level);
if (!IS_ERR(buf))
root->alloc_bytenr += blocksize;
return buf;
}
block_rsv = use_block_rsv(trans, root, blocksize);
if (IS_ERR(block_rsv))
return ERR_CAST(block_rsv);
ret = btrfs_reserve_extent(root, blocksize, blocksize,
empty_size, hint, &ins, 0, 0);
if (ret)
goto out_unuse;
buf = btrfs_init_new_buffer(trans, root, ins.objectid, level);
if (IS_ERR(buf)) {
ret = PTR_ERR(buf);
goto out_free_reserved;
}
if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) {
if (parent == 0)
parent = ins.objectid;
flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
} else
BUG_ON(parent > 0);
if (root_objectid != BTRFS_TREE_LOG_OBJECTID) {
extent_op = btrfs_alloc_delayed_extent_op();
if (!extent_op) {
ret = -ENOMEM;
goto out_free_buf;
}
if (key)
memcpy(&extent_op->key, key, sizeof(extent_op->key));
else
memset(&extent_op->key, 0, sizeof(extent_op->key));
extent_op->flags_to_set = flags;
if (skinny_metadata)
extent_op->update_key = 0;
else
extent_op->update_key = 1;
extent_op->update_flags = 1;
extent_op->is_data = 0;
extent_op->level = level;
ret = btrfs_add_delayed_tree_ref(root->fs_info, trans,
ins.objectid, ins.offset,
parent, root_objectid, level,
BTRFS_ADD_DELAYED_EXTENT,
extent_op, 0);
if (ret)
goto out_free_delayed;
}
return buf;
out_free_delayed:
btrfs_free_delayed_extent_op(extent_op);
out_free_buf:
free_extent_buffer(buf);
out_free_reserved:
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 0);
out_unuse:
unuse_block_rsv(root->fs_info, block_rsv, blocksize);
return ERR_PTR(ret);
}
struct walk_control {
u64 refs[BTRFS_MAX_LEVEL];
u64 flags[BTRFS_MAX_LEVEL];
struct btrfs_key update_progress;
int stage;
int level;
int shared_level;
int update_ref;
int keep_locks;
int reada_slot;
int reada_count;
int for_reloc;
};
#define DROP_REFERENCE 1
#define UPDATE_BACKREF 2
static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct walk_control *wc,
struct btrfs_path *path)
{
u64 bytenr;
u64 generation;
u64 refs;
u64 flags;
u32 nritems;
u32 blocksize;
struct btrfs_key key;
struct extent_buffer *eb;
int ret;
int slot;
int nread = 0;
if (path->slots[wc->level] < wc->reada_slot) {
wc->reada_count = wc->reada_count * 2 / 3;
wc->reada_count = max(wc->reada_count, 2);
} else {
wc->reada_count = wc->reada_count * 3 / 2;
wc->reada_count = min_t(int, wc->reada_count,
BTRFS_NODEPTRS_PER_BLOCK(root));
}
eb = path->nodes[wc->level];
nritems = btrfs_header_nritems(eb);
blocksize = root->nodesize;
for (slot = path->slots[wc->level]; slot < nritems; slot++) {
if (nread >= wc->reada_count)
break;
cond_resched();
bytenr = btrfs_node_blockptr(eb, slot);
generation = btrfs_node_ptr_generation(eb, slot);
if (slot == path->slots[wc->level])
goto reada;
if (wc->stage == UPDATE_BACKREF &&
generation <= root->root_key.offset)
continue;
/* We don't lock the tree block, it's OK to be racy here */
ret = btrfs_lookup_extent_info(trans, root, bytenr,
wc->level - 1, 1, &refs,
&flags);
/* We don't care about errors in readahead. */
if (ret < 0)
continue;
BUG_ON(refs == 0);
if (wc->stage == DROP_REFERENCE) {
if (refs == 1)
goto reada;
if (wc->level == 1 &&
(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
continue;
if (!wc->update_ref ||
generation <= root->root_key.offset)
continue;
btrfs_node_key_to_cpu(eb, &key, slot);
ret = btrfs_comp_cpu_keys(&key,
&wc->update_progress);
if (ret < 0)
continue;
} else {
if (wc->level == 1 &&
(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
continue;
}
reada:
readahead_tree_block(root, bytenr);
nread++;
}
wc->reada_slot = slot;
}
/*
* TODO: Modify related function to add related node/leaf to dirty_extent_root,
* for later qgroup accounting.
*
* Current, this function does nothing.
*/
static int account_leaf_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *eb)
{
int nr = btrfs_header_nritems(eb);
int i, extent_type;
struct btrfs_key key;
struct btrfs_file_extent_item *fi;
u64 bytenr, num_bytes;
for (i = 0; i < nr; i++) {
btrfs_item_key_to_cpu(eb, &key, i);
if (key.type != BTRFS_EXTENT_DATA_KEY)
continue;
fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item);
/* filter out non qgroup-accountable extents */
extent_type = btrfs_file_extent_type(eb, fi);
if (extent_type == BTRFS_FILE_EXTENT_INLINE)
continue;
bytenr = btrfs_file_extent_disk_bytenr(eb, fi);
if (!bytenr)
continue;
num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi);
}
return 0;
}
/*
* Walk up the tree from the bottom, freeing leaves and any interior
* nodes which have had all slots visited. If a node (leaf or
* interior) is freed, the node above it will have it's slot
* incremented. The root node will never be freed.
*
* At the end of this function, we should have a path which has all
* slots incremented to the next position for a search. If we need to
* read a new node it will be NULL and the node above it will have the
* correct slot selected for a later read.
*
* If we increment the root nodes slot counter past the number of
* elements, 1 is returned to signal completion of the search.
*/
static int adjust_slots_upwards(struct btrfs_root *root,
struct btrfs_path *path, int root_level)
{
int level = 0;
int nr, slot;
struct extent_buffer *eb;
if (root_level == 0)
return 1;
while (level <= root_level) {
eb = path->nodes[level];
nr = btrfs_header_nritems(eb);
path->slots[level]++;
slot = path->slots[level];
if (slot >= nr || level == 0) {
/*
* Don't free the root - we will detect this
* condition after our loop and return a
* positive value for caller to stop walking the tree.
*/
if (level != root_level) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
free_extent_buffer(eb);
path->nodes[level] = NULL;
path->slots[level] = 0;
}
} else {
/*
* We have a valid slot to walk back down
* from. Stop here so caller can process these
* new nodes.
*/
break;
}
level++;
}
eb = path->nodes[root_level];
if (path->slots[root_level] >= btrfs_header_nritems(eb))
return 1;
return 0;
}
/*
* root_eb is the subtree root and is locked before this function is called.
* TODO: Modify this function to mark all (including complete shared node)
* to dirty_extent_root to allow it get accounted in qgroup.
*/
static int account_shared_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *root_eb,
u64 root_gen,
int root_level)
{
int ret = 0;
int level;
struct extent_buffer *eb = root_eb;
struct btrfs_path *path = NULL;
BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL);
BUG_ON(root_eb == NULL);
if (!root->fs_info->quota_enabled)
return 0;
if (!extent_buffer_uptodate(root_eb)) {
ret = btrfs_read_buffer(root_eb, root_gen);
if (ret)
goto out;
}
if (root_level == 0) {
ret = account_leaf_items(trans, root, root_eb);
goto out;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* Walk down the tree. Missing extent blocks are filled in as
* we go. Metadata is accounted every time we read a new
* extent block.
*
* When we reach a leaf, we account for file extent items in it,
* walk back up the tree (adjusting slot pointers as we go)
* and restart the search process.
*/
extent_buffer_get(root_eb); /* For path */
path->nodes[root_level] = root_eb;
path->slots[root_level] = 0;
path->locks[root_level] = 0; /* so release_path doesn't try to unlock */
walk_down:
level = root_level;
while (level >= 0) {
if (path->nodes[level] == NULL) {
int parent_slot;
u64 child_gen;
u64 child_bytenr;
/* We need to get child blockptr/gen from
* parent before we can read it. */
eb = path->nodes[level + 1];
parent_slot = path->slots[level + 1];
child_bytenr = btrfs_node_blockptr(eb, parent_slot);
child_gen = btrfs_node_ptr_generation(eb, parent_slot);
eb = read_tree_block(root, child_bytenr, child_gen);
if (IS_ERR(eb)) {
ret = PTR_ERR(eb);
goto out;
} else if (!extent_buffer_uptodate(eb)) {
free_extent_buffer(eb);
ret = -EIO;
goto out;
}
path->nodes[level] = eb;
path->slots[level] = 0;
btrfs_tree_read_lock(eb);
btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
path->locks[level] = BTRFS_READ_LOCK_BLOCKING;
}
if (level == 0) {
ret = account_leaf_items(trans, root, path->nodes[level]);
if (ret)
goto out;
/* Nonzero return here means we completed our search */
ret = adjust_slots_upwards(root, path, root_level);
if (ret)
break;
/* Restart search with new slots */
goto walk_down;
}
level--;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper to process tree block while walking down the tree.
*
* when wc->stage == UPDATE_BACKREF, this function updates
* back refs for pointers in the block.
*
* NOTE: return value 1 means we should stop walking down.
*/
static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int lookup_info)
{
int level = wc->level;
struct extent_buffer *eb = path->nodes[level];
u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF;
int ret;
if (wc->stage == UPDATE_BACKREF &&
btrfs_header_owner(eb) != root->root_key.objectid)
return 1;
/*
* when reference count of tree block is 1, it won't increase
* again. once full backref flag is set, we never clear it.
*/
if (lookup_info &&
((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) ||
(wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) {
BUG_ON(!path->locks[level]);
ret = btrfs_lookup_extent_info(trans, root,
eb->start, level, 1,
&wc->refs[level],
&wc->flags[level]);
BUG_ON(ret == -ENOMEM);
if (ret)
return ret;
BUG_ON(wc->refs[level] == 0);
}
if (wc->stage == DROP_REFERENCE) {
if (wc->refs[level] > 1)
return 1;
if (path->locks[level] && !wc->keep_locks) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
}
return 0;
}
/* wc->stage == UPDATE_BACKREF */
if (!(wc->flags[level] & flag)) {
BUG_ON(!path->locks[level]);
ret = btrfs_inc_ref(trans, root, eb, 1);
BUG_ON(ret); /* -ENOMEM */
ret = btrfs_dec_ref(trans, root, eb, 0);
BUG_ON(ret); /* -ENOMEM */
ret = btrfs_set_disk_extent_flags(trans, root, eb->start,
eb->len, flag,
btrfs_header_level(eb), 0);
BUG_ON(ret); /* -ENOMEM */
wc->flags[level] |= flag;
}
/*
* the block is shared by multiple trees, so it's not good to
* keep the tree lock
*/
if (path->locks[level] && level > 0) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
}
return 0;
}
/*
* helper to process tree block pointer.
*
* when wc->stage == DROP_REFERENCE, this function checks
* reference count of the block pointed to. if the block
* is shared and we need update back refs for the subtree
* rooted at the block, this function changes wc->stage to
* UPDATE_BACKREF. if the block is shared and there is no
* need to update back, this function drops the reference
* to the block.
*
* NOTE: return value 1 means we should stop walking down.
*/
static noinline int do_walk_down(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int *lookup_info)
{
u64 bytenr;
u64 generation;
u64 parent;
u32 blocksize;
struct btrfs_key key;
struct extent_buffer *next;
int level = wc->level;
int reada = 0;
int ret = 0;
bool need_account = false;
generation = btrfs_node_ptr_generation(path->nodes[level],
path->slots[level]);
/*
* if the lower level block was created before the snapshot
* was created, we know there is no need to update back refs
* for the subtree
*/
if (wc->stage == UPDATE_BACKREF &&
generation <= root->root_key.offset) {
*lookup_info = 1;
return 1;
}
bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]);
blocksize = root->nodesize;
next = btrfs_find_tree_block(root->fs_info, bytenr);
if (!next) {
next = btrfs_find_create_tree_block(root, bytenr);
if (!next)
return -ENOMEM;
btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
level - 1);
reada = 1;
}
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1,
&wc->refs[level - 1],
&wc->flags[level - 1]);
if (ret < 0) {
btrfs_tree_unlock(next);
return ret;
}
if (unlikely(wc->refs[level - 1] == 0)) {
btrfs_err(root->fs_info, "Missing references.");
BUG();
}
*lookup_info = 0;
if (wc->stage == DROP_REFERENCE) {
if (wc->refs[level - 1] > 1) {
need_account = true;
if (level == 1 &&
(wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
goto skip;
if (!wc->update_ref ||
generation <= root->root_key.offset)
goto skip;
btrfs_node_key_to_cpu(path->nodes[level], &key,
path->slots[level]);
ret = btrfs_comp_cpu_keys(&key, &wc->update_progress);
if (ret < 0)
goto skip;
wc->stage = UPDATE_BACKREF;
wc->shared_level = level - 1;
}
} else {
if (level == 1 &&
(wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF))
goto skip;
}
if (!btrfs_buffer_uptodate(next, generation, 0)) {
btrfs_tree_unlock(next);
free_extent_buffer(next);
next = NULL;
*lookup_info = 1;
}
if (!next) {
if (reada && level == 1)
reada_walk_down(trans, root, wc, path);
next = read_tree_block(root, bytenr, generation);
if (IS_ERR(next)) {
return PTR_ERR(next);
} else if (!extent_buffer_uptodate(next)) {
free_extent_buffer(next);
return -EIO;
}
btrfs_tree_lock(next);
btrfs_set_lock_blocking(next);
}
level--;
BUG_ON(level != btrfs_header_level(next));
path->nodes[level] = next;
path->slots[level] = 0;
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
wc->level = level;
if (wc->level == 1)
wc->reada_slot = 0;
return 0;
skip:
wc->refs[level - 1] = 0;
wc->flags[level - 1] = 0;
if (wc->stage == DROP_REFERENCE) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
parent = path->nodes[level]->start;
} else {
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(path->nodes[level]));
parent = 0;
}
if (need_account) {
ret = account_shared_subtree(trans, root, next,
generation, level - 1);
if (ret) {
printk_ratelimited(KERN_ERR "BTRFS: %s Error "
"%d accounting shared subtree. Quota "
"is out of sync, rescan required.\n",
root->fs_info->sb->s_id, ret);
}
}
ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent,
root->root_key.objectid, level - 1, 0, 0);
BUG_ON(ret); /* -ENOMEM */
}
btrfs_tree_unlock(next);
free_extent_buffer(next);
*lookup_info = 1;
return 1;
}
/*
* helper to process tree block while walking up the tree.
*
* when wc->stage == DROP_REFERENCE, this function drops
* reference count on the block.
*
* when wc->stage == UPDATE_BACKREF, this function changes
* wc->stage back to DROP_REFERENCE if we changed wc->stage
* to UPDATE_BACKREF previously while processing the block.
*
* NOTE: return value 1 means we should stop walking up.
*/
static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc)
{
int ret;
int level = wc->level;
struct extent_buffer *eb = path->nodes[level];
u64 parent = 0;
if (wc->stage == UPDATE_BACKREF) {
BUG_ON(wc->shared_level < level);
if (level < wc->shared_level)
goto out;
ret = find_next_key(path, level + 1, &wc->update_progress);
if (ret > 0)
wc->update_ref = 0;
wc->stage = DROP_REFERENCE;
wc->shared_level = -1;
path->slots[level] = 0;
/*
* check reference count again if the block isn't locked.
* we should start walking down the tree again if reference
* count is one.
*/
if (!path->locks[level]) {
BUG_ON(level == 0);
btrfs_tree_lock(eb);
btrfs_set_lock_blocking(eb);
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
ret = btrfs_lookup_extent_info(trans, root,
eb->start, level, 1,
&wc->refs[level],
&wc->flags[level]);
if (ret < 0) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
return ret;
}
BUG_ON(wc->refs[level] == 0);
if (wc->refs[level] == 1) {
btrfs_tree_unlock_rw(eb, path->locks[level]);
path->locks[level] = 0;
return 1;
}
}
}
/* wc->stage == DROP_REFERENCE */
BUG_ON(wc->refs[level] > 1 && !path->locks[level]);
if (wc->refs[level] == 1) {
if (level == 0) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
ret = btrfs_dec_ref(trans, root, eb, 1);
else
ret = btrfs_dec_ref(trans, root, eb, 0);
BUG_ON(ret); /* -ENOMEM */
ret = account_leaf_items(trans, root, eb);
if (ret) {
printk_ratelimited(KERN_ERR "BTRFS: %s Error "
"%d accounting leaf items. Quota "
"is out of sync, rescan required.\n",
root->fs_info->sb->s_id, ret);
}
}
/* make block locked assertion in clean_tree_block happy */
if (!path->locks[level] &&
btrfs_header_generation(eb) == trans->transid) {
btrfs_tree_lock(eb);
btrfs_set_lock_blocking(eb);
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
}
clean_tree_block(trans, root->fs_info, eb);
}
if (eb == root->node) {
if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
parent = eb->start;
else
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(eb));
} else {
if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF)
parent = path->nodes[level + 1]->start;
else
BUG_ON(root->root_key.objectid !=
btrfs_header_owner(path->nodes[level + 1]));
}
btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
out:
wc->refs[level] = 0;
wc->flags[level] = 0;
return 0;
}
static noinline int walk_down_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc)
{
int level = wc->level;
int lookup_info = 1;
int ret;
while (level >= 0) {
ret = walk_down_proc(trans, root, path, wc, lookup_info);
if (ret > 0)
break;
if (level == 0)
break;
if (path->slots[level] >=
btrfs_header_nritems(path->nodes[level]))
break;
ret = do_walk_down(trans, root, path, wc, &lookup_info);
if (ret > 0) {
path->slots[level]++;
continue;
} else if (ret < 0)
return ret;
level = wc->level;
}
return 0;
}
static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct walk_control *wc, int max_level)
{
int level = wc->level;
int ret;
path->slots[level] = btrfs_header_nritems(path->nodes[level]);
while (level < max_level && path->nodes[level]) {
wc->level = level;
if (path->slots[level] + 1 <
btrfs_header_nritems(path->nodes[level])) {
path->slots[level]++;
return 0;
} else {
ret = walk_up_proc(trans, root, path, wc);
if (ret > 0)
return 0;
if (path->locks[level]) {
btrfs_tree_unlock_rw(path->nodes[level],
path->locks[level]);
path->locks[level] = 0;
}
free_extent_buffer(path->nodes[level]);
path->nodes[level] = NULL;
level++;
}
}
return 1;
}
/*
* drop a subvolume tree.
*
* this function traverses the tree freeing any blocks that only
* referenced by the tree.
*
* when a shared tree block is found. this function decreases its
* reference count by one. if update_ref is true, this function
* also make sure backrefs for the shared block and all lower level
* blocks are properly updated.
*
* If called with for_reloc == 0, may exit early with -EAGAIN
*/
int btrfs_drop_snapshot(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv, int update_ref,
int for_reloc)
{
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_root_item *root_item = &root->root_item;
struct walk_control *wc;
struct btrfs_key key;
int err = 0;
int ret;
int level;
bool root_dropped = false;
btrfs_debug(root->fs_info, "Drop subvolume %llu", root->objectid);
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
wc = kzalloc(sizeof(*wc), GFP_NOFS);
if (!wc) {
btrfs_free_path(path);
err = -ENOMEM;
goto out;
}
trans = btrfs_start_transaction(tree_root, 0);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_free;
}
if (block_rsv)
trans->block_rsv = block_rsv;
if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
level = btrfs_header_level(root->node);
path->nodes[level] = btrfs_lock_root_node(root);
btrfs_set_lock_blocking(path->nodes[level]);
path->slots[level] = 0;
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
memset(&wc->update_progress, 0,
sizeof(wc->update_progress));
} else {
btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
memcpy(&wc->update_progress, &key,
sizeof(wc->update_progress));
level = root_item->drop_level;
BUG_ON(level == 0);
path->lowest_level = level;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
path->lowest_level = 0;
if (ret < 0) {
err = ret;
goto out_end_trans;
}
WARN_ON(ret > 0);
/*
* unlock our path, this is safe because only this
* function is allowed to delete this snapshot
*/
btrfs_unlock_up_safe(path, 0);
level = btrfs_header_level(root->node);
while (1) {
btrfs_tree_lock(path->nodes[level]);
btrfs_set_lock_blocking(path->nodes[level]);
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
ret = btrfs_lookup_extent_info(trans, root,
path->nodes[level]->start,
level, 1, &wc->refs[level],
&wc->flags[level]);
if (ret < 0) {
err = ret;
goto out_end_trans;
}
BUG_ON(wc->refs[level] == 0);
if (level == root_item->drop_level)
break;
btrfs_tree_unlock(path->nodes[level]);
path->locks[level] = 0;
WARN_ON(wc->refs[level] != 1);
level--;
}
}
wc->level = level;
wc->shared_level = -1;
wc->stage = DROP_REFERENCE;
wc->update_ref = update_ref;
wc->keep_locks = 0;
wc->for_reloc = for_reloc;
wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
while (1) {
ret = walk_down_tree(trans, root, path, wc);
if (ret < 0) {
err = ret;
break;
}
ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL);
if (ret < 0) {
err = ret;
break;
}
if (ret > 0) {
BUG_ON(wc->stage != DROP_REFERENCE);
break;
}
if (wc->stage == DROP_REFERENCE) {
level = wc->level;
btrfs_node_key(path->nodes[level],
&root_item->drop_progress,
path->slots[level]);
root_item->drop_level = level;
}
BUG_ON(wc->level == 0);
if (btrfs_should_end_transaction(trans, tree_root) ||
(!for_reloc && btrfs_need_cleaner_sleep(root))) {
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
root_item);
if (ret) {
btrfs_abort_transaction(trans, tree_root, ret);
err = ret;
goto out_end_trans;
}
btrfs_end_transaction_throttle(trans, tree_root);
if (!for_reloc && btrfs_need_cleaner_sleep(root)) {
pr_debug("BTRFS: drop snapshot early exit\n");
err = -EAGAIN;
goto out_free;
}
trans = btrfs_start_transaction(tree_root, 0);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_free;
}
if (block_rsv)
trans->block_rsv = block_rsv;
}
}
btrfs_release_path(path);
if (err)
goto out_end_trans;
ret = btrfs_del_root(trans, tree_root, &root->root_key);
if (ret) {
btrfs_abort_transaction(trans, tree_root, ret);
goto out_end_trans;
}
if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
ret = btrfs_find_root(tree_root, &root->root_key, path,
NULL, NULL);
if (ret < 0) {
btrfs_abort_transaction(trans, tree_root, ret);
err = ret;
goto out_end_trans;
} else if (ret > 0) {
/* if we fail to delete the orphan item this time
* around, it'll get picked up the next time.
*
* The most common failure here is just -ENOENT.
*/
btrfs_del_orphan_item(trans, tree_root,
root->root_key.objectid);
}
}
if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) {
btrfs_add_dropped_root(trans, root);
} else {
free_extent_buffer(root->node);
free_extent_buffer(root->commit_root);
btrfs_put_fs_root(root);
}
root_dropped = true;
out_end_trans:
btrfs_end_transaction_throttle(trans, tree_root);
out_free:
kfree(wc);
btrfs_free_path(path);
out:
/*
* So if we need to stop dropping the snapshot for whatever reason we
* need to make sure to add it back to the dead root list so that we
* keep trying to do the work later. This also cleans up roots if we
* don't have it in the radix (like when we recover after a power fail
* or unmount) so we don't leak memory.
*/
if (!for_reloc && root_dropped == false)
btrfs_add_dead_root(root);
if (err && err != -EAGAIN)
btrfs_std_error(root->fs_info, err);
return err;
}
/*
* drop subtree rooted at tree block 'node'.
*
* NOTE: this function will unlock and release tree block 'node'
* only used by relocation code
*/
int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *node,
struct extent_buffer *parent)
{
struct btrfs_path *path;
struct walk_control *wc;
int level;
int parent_level;
int ret = 0;
int wret;
BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
wc = kzalloc(sizeof(*wc), GFP_NOFS);
if (!wc) {
btrfs_free_path(path);
return -ENOMEM;
}
btrfs_assert_tree_locked(parent);
parent_level = btrfs_header_level(parent);
extent_buffer_get(parent);
path->nodes[parent_level] = parent;
path->slots[parent_level] = btrfs_header_nritems(parent);
btrfs_assert_tree_locked(node);
level = btrfs_header_level(node);
path->nodes[level] = node;
path->slots[level] = 0;
path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
wc->refs[parent_level] = 1;
wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
wc->level = level;
wc->shared_level = -1;
wc->stage = DROP_REFERENCE;
wc->update_ref = 0;
wc->keep_locks = 1;
wc->for_reloc = 1;
wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root);
while (1) {
wret = walk_down_tree(trans, root, path, wc);
if (wret < 0) {
ret = wret;
break;
}
wret = walk_up_tree(trans, root, path, wc, parent_level);
if (wret < 0)
ret = wret;
if (wret != 0)
break;
}
kfree(wc);
btrfs_free_path(path);
return ret;
}
static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
{
u64 num_devices;
u64 stripped;
/*
* if restripe for this chunk_type is on pick target profile and
* return, otherwise do the usual balance
*/
stripped = get_restripe_target(root->fs_info, flags);
if (stripped)
return extended_to_chunk(stripped);
num_devices = root->fs_info->fs_devices->rw_devices;
stripped = BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10;
if (num_devices == 1) {
stripped |= BTRFS_BLOCK_GROUP_DUP;
stripped = flags & ~stripped;
/* turn raid0 into single device chunks */
if (flags & BTRFS_BLOCK_GROUP_RAID0)
return stripped;
/* turn mirroring into duplication */
if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
return stripped | BTRFS_BLOCK_GROUP_DUP;
} else {
/* they already had raid on here, just return */
if (flags & stripped)
return flags;
stripped |= BTRFS_BLOCK_GROUP_DUP;
stripped = flags & ~stripped;
/* switch duplicated blocks with raid1 */
if (flags & BTRFS_BLOCK_GROUP_DUP)
return stripped | BTRFS_BLOCK_GROUP_RAID1;
/* this is drive concat, leave it alone */
}
return flags;
}
static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache->space_info;
u64 num_bytes;
u64 min_allocable_bytes;
int ret = -ENOSPC;
/*
* We need some metadata space and system metadata space for
* allocating chunks in some corner cases until we force to set
* it to be readonly.
*/
if ((sinfo->flags &
(BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
!force)
min_allocable_bytes = 1 * 1024 * 1024;
else
min_allocable_bytes = 0;
spin_lock(&sinfo->lock);
spin_lock(&cache->lock);
if (cache->ro) {
cache->ro++;
ret = 0;
goto out;
}
num_bytes = cache->key.offset - cache->reserved - cache->pinned -
cache->bytes_super - btrfs_block_group_used(&cache->item);
if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes +
min_allocable_bytes <= sinfo->total_bytes) {
sinfo->bytes_readonly += num_bytes;
cache->ro++;
list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
ret = 0;
}
out:
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
return ret;
}
int btrfs_inc_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct btrfs_trans_handle *trans;
u64 alloc_flags;
int ret;
again:
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
/*
* we're not allowed to set block groups readonly after the dirty
* block groups cache has started writing. If it already started,
* back off and let this transaction commit
*/
mutex_lock(&root->fs_info->ro_block_group_mutex);
if (trans->transaction->dirty_bg_run) {
u64 transid = trans->transid;
mutex_unlock(&root->fs_info->ro_block_group_mutex);
btrfs_end_transaction(trans, root);
ret = btrfs_wait_for_commit(root, transid);
if (ret)
return ret;
goto again;
}
/*
* if we are changing raid levels, try to allocate a corresponding
* block group with the new raid level.
*/
alloc_flags = update_block_group_flags(root, cache->flags);
if (alloc_flags != cache->flags) {
ret = do_chunk_alloc(trans, root, alloc_flags,
CHUNK_ALLOC_FORCE);
/*
* ENOSPC is allowed here, we may have enough space
* already allocated at the new raid level to
* carry on
*/
if (ret == -ENOSPC)
ret = 0;
if (ret < 0)
goto out;
}
ret = inc_block_group_ro(cache, 0);
if (!ret)
goto out;
alloc_flags = get_alloc_profile(root, cache->space_info->flags);
ret = do_chunk_alloc(trans, root, alloc_flags,
CHUNK_ALLOC_FORCE);
if (ret < 0)
goto out;
ret = inc_block_group_ro(cache, 0);
out:
if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) {
alloc_flags = update_block_group_flags(root, cache->flags);
lock_chunks(root->fs_info->chunk_root);
check_system_chunk(trans, root, alloc_flags);
unlock_chunks(root->fs_info->chunk_root);
}
mutex_unlock(&root->fs_info->ro_block_group_mutex);
btrfs_end_transaction(trans, root);
return ret;
}
int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 type)
{
u64 alloc_flags = get_alloc_profile(root, type);
return do_chunk_alloc(trans, root, alloc_flags,
CHUNK_ALLOC_FORCE);
}
/*
* helper to account the unused space of all the readonly block group in the
* space_info. takes mirrors into account.
*/
u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
{
struct btrfs_block_group_cache *block_group;
u64 free_bytes = 0;
int factor;
/* It's df, we don't care if it's racey */
if (list_empty(&sinfo->ro_bgs))
return 0;
spin_lock(&sinfo->lock);
list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
spin_lock(&block_group->lock);
if (!block_group->ro) {
spin_unlock(&block_group->lock);
continue;
}
if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_DUP))
factor = 2;
else
factor = 1;
free_bytes += (block_group->key.offset -
btrfs_block_group_used(&block_group->item)) *
factor;
spin_unlock(&block_group->lock);
}
spin_unlock(&sinfo->lock);
return free_bytes;
}
void btrfs_dec_block_group_ro(struct btrfs_root *root,
struct btrfs_block_group_cache *cache)
{
struct btrfs_space_info *sinfo = cache->space_info;
u64 num_bytes;
BUG_ON(!cache->ro);
spin_lock(&sinfo->lock);
spin_lock(&cache->lock);
if (!--cache->ro) {
num_bytes = cache->key.offset - cache->reserved -
cache->pinned - cache->bytes_super -
btrfs_block_group_used(&cache->item);
sinfo->bytes_readonly -= num_bytes;
list_del_init(&cache->ro_list);
}
spin_unlock(&cache->lock);
spin_unlock(&sinfo->lock);
}
/*
* checks to see if its even possible to relocate this block group.
*
* @return - -1 if it's not a good idea to relocate this block group, 0 if its
* ok to go ahead and try.
*/
int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
struct btrfs_device *device;
struct btrfs_trans_handle *trans;
u64 min_free;
u64 dev_min = 1;
u64 dev_nr = 0;
u64 target;
int index;
int full = 0;
int ret = 0;
block_group = btrfs_lookup_block_group(root->fs_info, bytenr);
/* odd, couldn't find the block group, leave it alone */
if (!block_group)
return -1;
min_free = btrfs_block_group_used(&block_group->item);
/* no bytes used, we're good */
if (!min_free)
goto out;
space_info = block_group->space_info;
spin_lock(&space_info->lock);
full = space_info->full;
/*
* if this is the last block group we have in this space, we can't
* relocate it unless we're able to allocate a new chunk below.
*
* Otherwise, we need to make sure we have room in the space to handle
* all of the extents from this block group. If we can, we're good
*/
if ((space_info->total_bytes != block_group->key.offset) &&
(space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly +
min_free < space_info->total_bytes)) {
spin_unlock(&space_info->lock);
goto out;
}
spin_unlock(&space_info->lock);
/*
* ok we don't have enough space, but maybe we have free space on our
* devices to allocate new chunks for relocation, so loop through our
* alloc devices and guess if we have enough space. if this block
* group is going to be restriped, run checks against the target
* profile instead of the current one.
*/
ret = -1;
/*
* index:
* 0: raid10
* 1: raid1
* 2: dup
* 3: raid0
* 4: single
*/
target = get_restripe_target(root->fs_info, block_group->flags);
if (target) {
index = __get_raid_index(extended_to_chunk(target));
} else {
/*
* this is just a balance, so if we were marked as full
* we know there is no space for a new chunk
*/
if (full)
goto out;
index = get_block_group_index(block_group);
}
if (index == BTRFS_RAID_RAID10) {
dev_min = 4;
/* Divide by 2 */
min_free >>= 1;
} else if (index == BTRFS_RAID_RAID1) {
dev_min = 2;
} else if (index == BTRFS_RAID_DUP) {
/* Multiply by 2 */
min_free <<= 1;
} else if (index == BTRFS_RAID_RAID0) {
dev_min = fs_devices->rw_devices;
min_free = div64_u64(min_free, dev_min);
}
/* We need to do this so that we can look at pending chunks */
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
mutex_lock(&root->fs_info->chunk_mutex);
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
u64 dev_offset;
/*
* check to make sure we can actually find a chunk with enough
* space to fit our block group in.
*/
if (device->total_bytes > device->bytes_used + min_free &&
!device->is_tgtdev_for_dev_replace) {
ret = find_free_dev_extent(trans, device, min_free,
&dev_offset, NULL);
if (!ret)
dev_nr++;
if (dev_nr >= dev_min)
break;
ret = -1;
}
}
mutex_unlock(&root->fs_info->chunk_mutex);
btrfs_end_transaction(trans, root);
out:
btrfs_put_block_group(block_group);
return ret;
}
static int find_first_block_group(struct btrfs_root *root,
struct btrfs_path *path, struct btrfs_key *key)
{
int ret = 0;
struct btrfs_key found_key;
struct extent_buffer *leaf;
int slot;
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret < 0)
goto out;
while (1) {
slot = path->slots[0];
leaf = path->nodes[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
break;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid >= key->objectid &&
found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
ret = 0;
goto out;
}
path->slots[0]++;
}
out:
return ret;
}
void btrfs_put_block_group_cache(struct btrfs_fs_info *info)
{
struct btrfs_block_group_cache *block_group;
u64 last = 0;
while (1) {
struct inode *inode;
block_group = btrfs_lookup_first_block_group(info, last);
while (block_group) {
spin_lock(&block_group->lock);
if (block_group->iref)
break;
spin_unlock(&block_group->lock);
block_group = next_block_group(info->tree_root,
block_group);
}
if (!block_group) {
if (last == 0)
break;
last = 0;
continue;
}
inode = block_group->inode;
block_group->iref = 0;
block_group->inode = NULL;
spin_unlock(&block_group->lock);
iput(inode);
last = block_group->key.objectid + block_group->key.offset;
btrfs_put_block_group(block_group);
}
}
int btrfs_free_block_groups(struct btrfs_fs_info *info)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct btrfs_caching_control *caching_ctl;
struct rb_node *n;
down_write(&info->commit_root_sem);
while (!list_empty(&info->caching_block_groups)) {
caching_ctl = list_entry(info->caching_block_groups.next,
struct btrfs_caching_control, list);
list_del(&caching_ctl->list);
put_caching_control(caching_ctl);
}
up_write(&info->commit_root_sem);
spin_lock(&info->unused_bgs_lock);
while (!list_empty(&info->unused_bgs)) {
block_group = list_first_entry(&info->unused_bgs,
struct btrfs_block_group_cache,
bg_list);
list_del_init(&block_group->bg_list);
btrfs_put_block_group(block_group);
}
spin_unlock(&info->unused_bgs_lock);
spin_lock(&info->block_group_cache_lock);
while ((n = rb_last(&info->block_group_cache_tree)) != NULL) {
block_group = rb_entry(n, struct btrfs_block_group_cache,
cache_node);
rb_erase(&block_group->cache_node,
&info->block_group_cache_tree);
RB_CLEAR_NODE(&block_group->cache_node);
spin_unlock(&info->block_group_cache_lock);
down_write(&block_group->space_info->groups_sem);
list_del(&block_group->list);
up_write(&block_group->space_info->groups_sem);
if (block_group->cached == BTRFS_CACHE_STARTED)
wait_block_group_cache_done(block_group);
/*
* We haven't cached this block group, which means we could
* possibly have excluded extents on this block group.
*/
if (block_group->cached == BTRFS_CACHE_NO ||
block_group->cached == BTRFS_CACHE_ERROR)
free_excluded_extents(info->extent_root, block_group);
btrfs_remove_free_space_cache(block_group);
btrfs_put_block_group(block_group);
spin_lock(&info->block_group_cache_lock);
}
spin_unlock(&info->block_group_cache_lock);
/* now that all the block groups are freed, go through and
* free all the space_info structs. This is only called during
* the final stages of unmount, and so we know nobody is
* using them. We call synchronize_rcu() once before we start,
* just to be on the safe side.
*/
synchronize_rcu();
release_global_block_rsv(info);
while (!list_empty(&info->space_info)) {
int i;
space_info = list_entry(info->space_info.next,
struct btrfs_space_info,
list);
if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) {
if (WARN_ON(space_info->bytes_pinned > 0 ||
space_info->bytes_reserved > 0 ||
space_info->bytes_may_use > 0)) {
dump_space_info(space_info, 0, 0);
}
}
list_del(&space_info->list);
for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
struct kobject *kobj;
kobj = space_info->block_group_kobjs[i];
space_info->block_group_kobjs[i] = NULL;
if (kobj) {
kobject_del(kobj);
kobject_put(kobj);
}
}
kobject_del(&space_info->kobj);
kobject_put(&space_info->kobj);
}
return 0;
}
static void __link_block_group(struct btrfs_space_info *space_info,
struct btrfs_block_group_cache *cache)
{
int index = get_block_group_index(cache);
bool first = false;
down_write(&space_info->groups_sem);
if (list_empty(&space_info->block_groups[index]))
first = true;
list_add_tail(&cache->list, &space_info->block_groups[index]);
up_write(&space_info->groups_sem);
if (first) {
struct raid_kobject *rkobj;
int ret;
rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS);
if (!rkobj)
goto out_err;
rkobj->raid_type = index;
kobject_init(&rkobj->kobj, &btrfs_raid_ktype);
ret = kobject_add(&rkobj->kobj, &space_info->kobj,
"%s", get_raid_name(index));
if (ret) {
kobject_put(&rkobj->kobj);
goto out_err;
}
space_info->block_group_kobjs[index] = &rkobj->kobj;
}
return;
out_err:
pr_warn("BTRFS: failed to add kobject for block cache. ignoring.\n");
}
static struct btrfs_block_group_cache *
btrfs_create_block_group_cache(struct btrfs_root *root, u64 start, u64 size)
{
struct btrfs_block_group_cache *cache;
cache = kzalloc(sizeof(*cache), GFP_NOFS);
if (!cache)
return NULL;
cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
GFP_NOFS);
if (!cache->free_space_ctl) {
kfree(cache);
return NULL;
}
cache->key.objectid = start;
cache->key.offset = size;
cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
cache->sectorsize = root->sectorsize;
cache->fs_info = root->fs_info;
cache->full_stripe_len = btrfs_full_stripe_len(root,
&root->fs_info->mapping_tree,
start);
atomic_set(&cache->count, 1);
spin_lock_init(&cache->lock);
init_rwsem(&cache->data_rwsem);
INIT_LIST_HEAD(&cache->list);
INIT_LIST_HEAD(&cache->cluster_list);
INIT_LIST_HEAD(&cache->bg_list);
INIT_LIST_HEAD(&cache->ro_list);
INIT_LIST_HEAD(&cache->dirty_list);
INIT_LIST_HEAD(&cache->io_list);
btrfs_init_free_space_ctl(cache);
atomic_set(&cache->trimming, 0);
return cache;
}
int btrfs_read_block_groups(struct btrfs_root *root)
{
struct btrfs_path *path;
int ret;
struct btrfs_block_group_cache *cache;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_space_info *space_info;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf;
int need_clear = 0;
u64 cache_gen;
root = info->extent_root;
key.objectid = 0;
key.offset = 0;
key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 1;
cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
if (btrfs_test_opt(root, SPACE_CACHE) &&
btrfs_super_generation(root->fs_info->super_copy) != cache_gen)
need_clear = 1;
if (btrfs_test_opt(root, CLEAR_CACHE))
need_clear = 1;
while (1) {
ret = find_first_block_group(root, path, &key);
if (ret > 0)
break;
if (ret != 0)
goto error;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
cache = btrfs_create_block_group_cache(root, found_key.objectid,
found_key.offset);
if (!cache) {
ret = -ENOMEM;
goto error;
}
if (need_clear) {
/*
* When we mount with old space cache, we need to
* set BTRFS_DC_CLEAR and set dirty flag.
*
* a) Setting 'BTRFS_DC_CLEAR' makes sure that we
* truncate the old free space cache inode and
* setup a new one.
* b) Setting 'dirty flag' makes sure that we flush
* the new space cache info onto disk.
*/
if (btrfs_test_opt(root, SPACE_CACHE))
cache->disk_cache_state = BTRFS_DC_CLEAR;
}
read_extent_buffer(leaf, &cache->item,
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(cache->item));
cache->flags = btrfs_block_group_flags(&cache->item);
key.objectid = found_key.objectid + found_key.offset;
btrfs_release_path(path);
/*
* We need to exclude the super stripes now so that the space
* info has super bytes accounted for, otherwise we'll think
* we have more space than we actually do.
*/
ret = exclude_super_stripes(root, cache);
if (ret) {
/*
* We may have excluded something, so call this just in
* case.
*/
free_excluded_extents(root, cache);
btrfs_put_block_group(cache);
goto error;
}
/*
* check for two cases, either we are full, and therefore
* don't need to bother with the caching work since we won't
* find any space, or we are empty, and we can just add all
* the space in and be done with it. This saves us _alot_ of
* time, particularly in the full case.
*/
if (found_key.offset == btrfs_block_group_used(&cache->item)) {
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
free_excluded_extents(root, cache);
} else if (btrfs_block_group_used(&cache->item) == 0) {
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
add_new_free_space(cache, root->fs_info,
found_key.objectid,
found_key.objectid +
found_key.offset);
free_excluded_extents(root, cache);
}
ret = btrfs_add_block_group_cache(root->fs_info, cache);
if (ret) {
btrfs_remove_free_space_cache(cache);
btrfs_put_block_group(cache);
goto error;
}
ret = update_space_info(info, cache->flags, found_key.offset,
btrfs_block_group_used(&cache->item),
&space_info);
if (ret) {
btrfs_remove_free_space_cache(cache);
spin_lock(&info->block_group_cache_lock);
rb_erase(&cache->cache_node,
&info->block_group_cache_tree);
RB_CLEAR_NODE(&cache->cache_node);
spin_unlock(&info->block_group_cache_lock);
btrfs_put_block_group(cache);
goto error;
}
cache->space_info = space_info;
spin_lock(&cache->space_info->lock);
cache->space_info->bytes_readonly += cache->bytes_super;
spin_unlock(&cache->space_info->lock);
__link_block_group(space_info, cache);
set_avail_alloc_bits(root->fs_info, cache->flags);
if (btrfs_chunk_readonly(root, cache->key.objectid)) {
inc_block_group_ro(cache, 1);
} else if (btrfs_block_group_used(&cache->item) == 0) {
spin_lock(&info->unused_bgs_lock);
/* Should always be true but just in case. */
if (list_empty(&cache->bg_list)) {
btrfs_get_block_group(cache);
list_add_tail(&cache->bg_list,
&info->unused_bgs);
}
spin_unlock(&info->unused_bgs_lock);
}
}
list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
if (!(get_alloc_profile(root, space_info->flags) &
(BTRFS_BLOCK_GROUP_RAID10 |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID5 |
BTRFS_BLOCK_GROUP_RAID6 |
BTRFS_BLOCK_GROUP_DUP)))
continue;
/*
* avoid allocating from un-mirrored block group if there are
* mirrored block groups.
*/
list_for_each_entry(cache,
&space_info->block_groups[BTRFS_RAID_RAID0],
list)
inc_block_group_ro(cache, 1);
list_for_each_entry(cache,
&space_info->block_groups[BTRFS_RAID_SINGLE],
list)
inc_block_group_ro(cache, 1);
}
init_global_block_rsv(info);
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_group_cache *block_group, *tmp;
struct btrfs_root *extent_root = root->fs_info->extent_root;
struct btrfs_block_group_item item;
struct btrfs_key key;
int ret = 0;
list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) {
if (ret)
goto next;
spin_lock(&block_group->lock);
memcpy(&item, &block_group->item, sizeof(item));
memcpy(&key, &block_group->key, sizeof(key));
spin_unlock(&block_group->lock);
ret = btrfs_insert_item(trans, extent_root, &key, &item,
sizeof(item));
if (ret)
btrfs_abort_transaction(trans, extent_root, ret);
ret = btrfs_finish_chunk_alloc(trans, extent_root,
key.objectid, key.offset);
if (ret)
btrfs_abort_transaction(trans, extent_root, ret);
next:
list_del_init(&block_group->bg_list);
}
}
int btrfs_make_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 bytes_used,
u64 type, u64 chunk_objectid, u64 chunk_offset,
u64 size)
{
int ret;
struct btrfs_root *extent_root;
struct btrfs_block_group_cache *cache;
extent_root = root->fs_info->extent_root;
btrfs_set_log_full_commit(root->fs_info, trans);
cache = btrfs_create_block_group_cache(root, chunk_offset, size);
if (!cache)
return -ENOMEM;
btrfs_set_block_group_used(&cache->item, bytes_used);
btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
btrfs_set_block_group_flags(&cache->item, type);
cache->flags = type;
cache->last_byte_to_unpin = (u64)-1;
cache->cached = BTRFS_CACHE_FINISHED;
ret = exclude_super_stripes(root, cache);
if (ret) {
/*
* We may have excluded something, so call this just in
* case.
*/
free_excluded_extents(root, cache);
btrfs_put_block_group(cache);
return ret;
}
add_new_free_space(cache, root->fs_info, chunk_offset,
chunk_offset + size);
free_excluded_extents(root, cache);
/*
* Call to ensure the corresponding space_info object is created and
* assigned to our block group, but don't update its counters just yet.
* We want our bg to be added to the rbtree with its ->space_info set.
*/
ret = update_space_info(root->fs_info, cache->flags, 0, 0,
&cache->space_info);
if (ret) {
btrfs_remove_free_space_cache(cache);
btrfs_put_block_group(cache);
return ret;
}
ret = btrfs_add_block_group_cache(root->fs_info, cache);
if (ret) {
btrfs_remove_free_space_cache(cache);
btrfs_put_block_group(cache);
return ret;
}
/*
* Now that our block group has its ->space_info set and is inserted in
* the rbtree, update the space info's counters.
*/
ret = update_space_info(root->fs_info, cache->flags, size, bytes_used,
&cache->space_info);
if (ret) {
btrfs_remove_free_space_cache(cache);
spin_lock(&root->fs_info->block_group_cache_lock);
rb_erase(&cache->cache_node,
&root->fs_info->block_group_cache_tree);
RB_CLEAR_NODE(&cache->cache_node);
spin_unlock(&root->fs_info->block_group_cache_lock);
btrfs_put_block_group(cache);
return ret;
}
update_global_block_rsv(root->fs_info);
spin_lock(&cache->space_info->lock);
cache->space_info->bytes_readonly += cache->bytes_super;
spin_unlock(&cache->space_info->lock);
__link_block_group(cache->space_info, cache);
list_add_tail(&cache->bg_list, &trans->new_bgs);
set_avail_alloc_bits(extent_root->fs_info, type);
return 0;
}
static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
{
u64 extra_flags = chunk_to_extended(flags) &
BTRFS_EXTENDED_PROFILE_MASK;
write_seqlock(&fs_info->profiles_lock);
if (flags & BTRFS_BLOCK_GROUP_DATA)
fs_info->avail_data_alloc_bits &= ~extra_flags;
if (flags & BTRFS_BLOCK_GROUP_METADATA)
fs_info->avail_metadata_alloc_bits &= ~extra_flags;
if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
fs_info->avail_system_alloc_bits &= ~extra_flags;
write_sequnlock(&fs_info->profiles_lock);
}
int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 group_start,
struct extent_map *em)
{
struct btrfs_path *path;
struct btrfs_block_group_cache *block_group;
struct btrfs_free_cluster *cluster;
struct btrfs_root *tree_root = root->fs_info->tree_root;
struct btrfs_key key;
struct inode *inode;
struct kobject *kobj = NULL;
int ret;
int index;
int factor;
struct btrfs_caching_control *caching_ctl = NULL;
bool remove_em;
root = root->fs_info->extent_root;
block_group = btrfs_lookup_block_group(root->fs_info, group_start);
BUG_ON(!block_group);
BUG_ON(!block_group->ro);
/*
* Free the reserved super bytes from this block group before
* remove it.
*/
free_excluded_extents(root, block_group);
memcpy(&key, &block_group->key, sizeof(key));
index = get_block_group_index(block_group);
if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
/* make sure this block group isn't part of an allocation cluster */
cluster = &root->fs_info->data_alloc_cluster;
spin_lock(&cluster->refill_lock);
btrfs_return_cluster_to_free_space(block_group, cluster);
spin_unlock(&cluster->refill_lock);
/*
* make sure this block group isn't part of a metadata
* allocation cluster
*/
cluster = &root->fs_info->meta_alloc_cluster;
spin_lock(&cluster->refill_lock);
btrfs_return_cluster_to_free_space(block_group, cluster);
spin_unlock(&cluster->refill_lock);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
/*
* get the inode first so any iput calls done for the io_list
* aren't the final iput (no unlinks allowed now)
*/
inode = lookup_free_space_inode(tree_root, block_group, path);
mutex_lock(&trans->transaction->cache_write_mutex);
/*
* make sure our free spache cache IO is done before remove the
* free space inode
*/
spin_lock(&trans->transaction->dirty_bgs_lock);
if (!list_empty(&block_group->io_list)) {
list_del_init(&block_group->io_list);
WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode);
spin_unlock(&trans->transaction->dirty_bgs_lock);
btrfs_wait_cache_io(root, trans, block_group,
&block_group->io_ctl, path,
block_group->key.objectid);
btrfs_put_block_group(block_group);
spin_lock(&trans->transaction->dirty_bgs_lock);
}
if (!list_empty(&block_group->dirty_list)) {
list_del_init(&block_group->dirty_list);
btrfs_put_block_group(block_group);
}
spin_unlock(&trans->transaction->dirty_bgs_lock);
mutex_unlock(&trans->transaction->cache_write_mutex);
if (!IS_ERR(inode)) {
ret = btrfs_orphan_add(trans, inode);
if (ret) {
btrfs_add_delayed_iput(inode);
goto out;
}
clear_nlink(inode);
/* One for the block groups ref */
spin_lock(&block_group->lock);
if (block_group->iref) {
block_group->iref = 0;
block_group->inode = NULL;
spin_unlock(&block_group->lock);
iput(inode);
} else {
spin_unlock(&block_group->lock);
}
/* One for our lookup ref */
btrfs_add_delayed_iput(inode);
}
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = block_group->key.objectid;
key.type = 0;
ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0)
btrfs_release_path(path);
if (ret == 0) {
ret = btrfs_del_item(trans, tree_root, path);
if (ret)
goto out;
btrfs_release_path(path);
}
spin_lock(&root->fs_info->block_group_cache_lock);
rb_erase(&block_group->cache_node,
&root->fs_info->block_group_cache_tree);
RB_CLEAR_NODE(&block_group->cache_node);
if (root->fs_info->first_logical_byte == block_group->key.objectid)
root->fs_info->first_logical_byte = (u64)-1;
spin_unlock(&root->fs_info->block_group_cache_lock);
down_write(&block_group->space_info->groups_sem);
/*
* we must use list_del_init so people can check to see if they
* are still on the list after taking the semaphore
*/
list_del_init(&block_group->list);
if (list_empty(&block_group->space_info->block_groups[index])) {
kobj = block_group->space_info->block_group_kobjs[index];
block_group->space_info->block_group_kobjs[index] = NULL;
clear_avail_alloc_bits(root->fs_info, block_group->flags);
}
up_write(&block_group->space_info->groups_sem);
if (kobj) {
kobject_del(kobj);
kobject_put(kobj);
}
if (block_group->has_caching_ctl)
caching_ctl = get_caching_control(block_group);
if (block_group->cached == BTRFS_CACHE_STARTED)
wait_block_group_cache_done(block_group);
if (block_group->has_caching_ctl) {
down_write(&root->fs_info->commit_root_sem);
if (!caching_ctl) {
struct btrfs_caching_control *ctl;
list_for_each_entry(ctl,
&root->fs_info->caching_block_groups, list)
if (ctl->block_group == block_group) {
caching_ctl = ctl;
atomic_inc(&caching_ctl->count);
break;
}
}
if (caching_ctl)
list_del_init(&caching_ctl->list);
up_write(&root->fs_info->commit_root_sem);
if (caching_ctl) {
/* Once for the caching bgs list and once for us. */
put_caching_control(caching_ctl);
put_caching_control(caching_ctl);
}
}
spin_lock(&trans->transaction->dirty_bgs_lock);
if (!list_empty(&block_group->dirty_list)) {
WARN_ON(1);
}
if (!list_empty(&block_group->io_list)) {
WARN_ON(1);
}
spin_unlock(&trans->transaction->dirty_bgs_lock);
btrfs_remove_free_space_cache(block_group);
spin_lock(&block_group->space_info->lock);
list_del_init(&block_group->ro_list);
if (btrfs_test_opt(root, ENOSPC_DEBUG)) {
WARN_ON(block_group->space_info->total_bytes
< block_group->key.offset);
WARN_ON(block_group->space_info->bytes_readonly
< block_group->key.offset);
WARN_ON(block_group->space_info->disk_total
< block_group->key.offset * factor);
}
block_group->space_info->total_bytes -= block_group->key.offset;
block_group->space_info->bytes_readonly -= block_group->key.offset;
block_group->space_info->disk_total -= block_group->key.offset * factor;
spin_unlock(&block_group->space_info->lock);
memcpy(&key, &block_group->key, sizeof(key));
lock_chunks(root);
if (!list_empty(&em->list)) {
/* We're in the transaction->pending_chunks list. */
free_extent_map(em);
}
spin_lock(&block_group->lock);
block_group->removed = 1;
/*
* At this point trimming can't start on this block group, because we
* removed the block group from the tree fs_info->block_group_cache_tree
* so no one can't find it anymore and even if someone already got this
* block group before we removed it from the rbtree, they have already
* incremented block_group->trimming - if they didn't, they won't find
* any free space entries because we already removed them all when we
* called btrfs_remove_free_space_cache().
*
* And we must not remove the extent map from the fs_info->mapping_tree
* to prevent the same logical address range and physical device space
* ranges from being reused for a new block group. This is because our
* fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is
* completely transactionless, so while it is trimming a range the
* currently running transaction might finish and a new one start,
* allowing for new block groups to be created that can reuse the same
* physical device locations unless we take this special care.
*
* There may also be an implicit trim operation if the file system
* is mounted with -odiscard. The same protections must remain
* in place until the extents have been discarded completely when
* the transaction commit has completed.
*/
remove_em = (atomic_read(&block_group->trimming) == 0);
/*
* Make sure a trimmer task always sees the em in the pinned_chunks list
* if it sees block_group->removed == 1 (needs to lock block_group->lock
* before checking block_group->removed).
*/
if (!remove_em) {
/*
* Our em might be in trans->transaction->pending_chunks which
* is protected by fs_info->chunk_mutex ([lock|unlock]_chunks),
* and so is the fs_info->pinned_chunks list.
*
* So at this point we must be holding the chunk_mutex to avoid
* any races with chunk allocation (more specifically at
* volumes.c:contains_pending_extent()), to ensure it always
* sees the em, either in the pending_chunks list or in the
* pinned_chunks list.
*/
list_move_tail(&em->list, &root->fs_info->pinned_chunks);
}
spin_unlock(&block_group->lock);
if (remove_em) {
struct extent_map_tree *em_tree;
em_tree = &root->fs_info->mapping_tree.map_tree;
write_lock(&em_tree->lock);
/*
* The em might be in the pending_chunks list, so make sure the
* chunk mutex is locked, since remove_extent_mapping() will
* delete us from that list.
*/
remove_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
/* once for the tree */
free_extent_map(em);
}
unlock_chunks(root);
btrfs_put_block_group(block_group);
btrfs_put_block_group(block_group);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0)
ret = -EIO;
if (ret < 0)
goto out;
ret = btrfs_del_item(trans, root, path);
out:
btrfs_free_path(path);
return ret;
}
/*
* Process the unused_bgs list and remove any that don't have any allocated
* space inside of them.
*/
void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_space_info *space_info;
struct btrfs_root *root = fs_info->extent_root;
struct btrfs_trans_handle *trans;
int ret = 0;
if (!fs_info->open)
return;
spin_lock(&fs_info->unused_bgs_lock);
while (!list_empty(&fs_info->unused_bgs)) {
u64 start, end;
int trimming;
block_group = list_first_entry(&fs_info->unused_bgs,
struct btrfs_block_group_cache,
bg_list);
space_info = block_group->space_info;
list_del_init(&block_group->bg_list);
if (ret || btrfs_mixed_space_info(space_info)) {
btrfs_put_block_group(block_group);
continue;
}
spin_unlock(&fs_info->unused_bgs_lock);
mutex_lock(&root->fs_info->delete_unused_bgs_mutex);
/* Don't want to race with allocators so take the groups_sem */
down_write(&space_info->groups_sem);
spin_lock(&block_group->lock);
if (block_group->reserved ||
btrfs_block_group_used(&block_group->item) ||
block_group->ro) {
/*
* We want to bail if we made new allocations or have
* outstanding allocations in this block group. We do
* the ro check in case balance is currently acting on
* this block group.
*/
spin_unlock(&block_group->lock);
up_write(&space_info->groups_sem);
goto next;
}
spin_unlock(&block_group->lock);
/* We don't want to force the issue, only flip if it's ok. */
ret = inc_block_group_ro(block_group, 0);
up_write(&space_info->groups_sem);
if (ret < 0) {
ret = 0;
goto next;
}
/*
* Want to do this before we do anything else so we can recover
* properly if we fail to join the transaction.
*/
/* 1 for btrfs_orphan_reserve_metadata() */
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_dec_block_group_ro(root, block_group);
ret = PTR_ERR(trans);
goto next;
}
/*
* We could have pending pinned extents for this block group,
* just delete them, we don't care about them anymore.
*/
start = block_group->key.objectid;
end = start + block_group->key.offset - 1;
/*
* Hold the unused_bg_unpin_mutex lock to avoid racing with
* btrfs_finish_extent_commit(). If we are at transaction N,
* another task might be running finish_extent_commit() for the
* previous transaction N - 1, and have seen a range belonging
* to the block group in freed_extents[] before we were able to
* clear the whole block group range from freed_extents[]. This
* means that task can lookup for the block group after we
* unpinned it from freed_extents[] and removed it, leading to
* a BUG_ON() at btrfs_unpin_extent_range().
*/
mutex_lock(&fs_info->unused_bg_unpin_mutex);
ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
EXTENT_DIRTY, GFP_NOFS);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
btrfs_dec_block_group_ro(root, block_group);
goto end_trans;
}
ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
EXTENT_DIRTY, GFP_NOFS);
if (ret) {
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
btrfs_dec_block_group_ro(root, block_group);
goto end_trans;
}
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
/* Reset pinned so btrfs_put_block_group doesn't complain */
spin_lock(&space_info->lock);
spin_lock(&block_group->lock);
space_info->bytes_pinned -= block_group->pinned;
space_info->bytes_readonly += block_group->pinned;
percpu_counter_add(&space_info->total_bytes_pinned,
-block_group->pinned);
block_group->pinned = 0;
spin_unlock(&block_group->lock);
spin_unlock(&space_info->lock);
/* DISCARD can flip during remount */
trimming = btrfs_test_opt(root, DISCARD);
/* Implicit trim during transaction commit. */
if (trimming)
btrfs_get_block_group_trimming(block_group);
/*
* Btrfs_remove_chunk will abort the transaction if things go
* horribly wrong.
*/
ret = btrfs_remove_chunk(trans, root,
block_group->key.objectid);
if (ret) {
if (trimming)
btrfs_put_block_group_trimming(block_group);
goto end_trans;
}
/*
* If we're not mounted with -odiscard, we can just forget
* about this block group. Otherwise we'll need to wait
* until transaction commit to do the actual discard.
*/
if (trimming) {
WARN_ON(!list_empty(&block_group->bg_list));
spin_lock(&trans->transaction->deleted_bgs_lock);
list_move(&block_group->bg_list,
&trans->transaction->deleted_bgs);
spin_unlock(&trans->transaction->deleted_bgs_lock);
btrfs_get_block_group(block_group);
}
end_trans:
btrfs_end_transaction(trans, root);
next:
mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
btrfs_put_block_group(block_group);
spin_lock(&fs_info->unused_bgs_lock);
}
spin_unlock(&fs_info->unused_bgs_lock);
}
int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
{
struct btrfs_space_info *space_info;
struct btrfs_super_block *disk_super;
u64 features;
u64 flags;
int mixed = 0;
int ret;
disk_super = fs_info->super_copy;
if (!btrfs_super_root(disk_super))
return 1;
features = btrfs_super_incompat_flags(disk_super);
if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
mixed = 1;
flags = BTRFS_BLOCK_GROUP_SYSTEM;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
if (ret)
goto out;
if (mixed) {
flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
} else {
flags = BTRFS_BLOCK_GROUP_METADATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
if (ret)
goto out;
flags = BTRFS_BLOCK_GROUP_DATA;
ret = update_space_info(fs_info, flags, 0, 0, &space_info);
}
out:
return ret;
}
int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
{
return unpin_extent_range(root, start, end, false);
}
/*
* It used to be that old block groups would be left around forever.
* Iterating over them would be enough to trim unused space. Since we
* now automatically remove them, we also need to iterate over unallocated
* space.
*
* We don't want a transaction for this since the discard may take a
* substantial amount of time. We don't require that a transaction be
* running, but we do need to take a running transaction into account
* to ensure that we're not discarding chunks that were released in
* the current transaction.
*
* Holding the chunks lock will prevent other threads from allocating
* or releasing chunks, but it won't prevent a running transaction
* from committing and releasing the memory that the pending chunks
* list head uses. For that, we need to take a reference to the
* transaction.
*/
static int btrfs_trim_free_extents(struct btrfs_device *device,
u64 minlen, u64 *trimmed)
{
u64 start = 0, len = 0;
int ret;
*trimmed = 0;
/* Not writeable = nothing to do. */
if (!device->writeable)
return 0;
/* No free space = nothing to do. */
if (device->total_bytes <= device->bytes_used)
return 0;
ret = 0;
while (1) {
struct btrfs_fs_info *fs_info = device->dev_root->fs_info;
struct btrfs_transaction *trans;
u64 bytes;
ret = mutex_lock_interruptible(&fs_info->chunk_mutex);
if (ret)
return ret;
down_read(&fs_info->commit_root_sem);
spin_lock(&fs_info->trans_lock);
trans = fs_info->running_transaction;
if (trans)
atomic_inc(&trans->use_count);
spin_unlock(&fs_info->trans_lock);
ret = find_free_dev_extent_start(trans, device, minlen, start,
&start, &len);
if (trans)
btrfs_put_transaction(trans);
if (ret) {
up_read(&fs_info->commit_root_sem);
mutex_unlock(&fs_info->chunk_mutex);
if (ret == -ENOSPC)
ret = 0;
break;
}
ret = btrfs_issue_discard(device->bdev, start, len, &bytes);
up_read(&fs_info->commit_root_sem);
mutex_unlock(&fs_info->chunk_mutex);
if (ret)
break;
start += len;
*trimmed += bytes;
if (fatal_signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
cond_resched();
}
return ret;
}
int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_group_cache *cache = NULL;
struct btrfs_device *device;
struct list_head *devices;
u64 group_trimmed;
u64 start;
u64 end;
u64 trimmed = 0;
u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy);
int ret = 0;
/*
* try to trim all FS space, our block group may start from non-zero.
*/
if (range->len == total_bytes)
cache = btrfs_lookup_first_block_group(fs_info, range->start);
else
cache = btrfs_lookup_block_group(fs_info, range->start);
while (cache) {
if (cache->key.objectid >= (range->start + range->len)) {
btrfs_put_block_group(cache);
break;
}
start = max(range->start, cache->key.objectid);
end = min(range->start + range->len,
cache->key.objectid + cache->key.offset);
if (end - start >= range->minlen) {
if (!block_group_cache_done(cache)) {
ret = cache_block_group(cache, 0);
if (ret) {
btrfs_put_block_group(cache);
break;
}
ret = wait_block_group_cache_done(cache);
if (ret) {
btrfs_put_block_group(cache);
break;
}
}
ret = btrfs_trim_block_group(cache,
&group_trimmed,
start,
end,
range->minlen);
trimmed += group_trimmed;
if (ret) {
btrfs_put_block_group(cache);
break;
}
}
cache = next_block_group(fs_info->tree_root, cache);
}
mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
devices = &root->fs_info->fs_devices->alloc_list;
list_for_each_entry(device, devices, dev_alloc_list) {
ret = btrfs_trim_free_extents(device, range->minlen,
&group_trimmed);
if (ret)
break;
trimmed += group_trimmed;
}
mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
range->len = trimmed;
return ret;
}
/*
* btrfs_{start,end}_write_no_snapshoting() are similar to
* mnt_{want,drop}_write(), they are used to prevent some tasks from writing
* data into the page cache through nocow before the subvolume is snapshoted,
* but flush the data into disk after the snapshot creation, or to prevent
* operations while snapshoting is ongoing and that cause the snapshot to be
* inconsistent (writes followed by expanding truncates for example).
*/
void btrfs_end_write_no_snapshoting(struct btrfs_root *root)
{
percpu_counter_dec(&root->subv_writers->counter);
/*
* Make sure counter is updated before we wake up
* waiters.
*/
smp_mb();
if (waitqueue_active(&root->subv_writers->wait))
wake_up(&root->subv_writers->wait);
}
int btrfs_start_write_no_snapshoting(struct btrfs_root *root)
{
if (atomic_read(&root->will_be_snapshoted))
return 0;
percpu_counter_inc(&root->subv_writers->counter);
/*
* Make sure counter is updated before we check for snapshot creation.
*/
smp_mb();
if (atomic_read(&root->will_be_snapshoted)) {
btrfs_end_write_no_snapshoting(root);
return 0;
}
return 1;
}
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