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linux_dsm_epyc7002/fs/btrfs/inode.c
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00

10279 lines
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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/kernel.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include <linux/bit_spinlock.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/falloc.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/mount.h>
#include <linux/btrfs.h>
#include <linux/blkdev.h>
#include <linux/posix_acl_xattr.h>
#include <linux/uio.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "print-tree.h"
#include "ordered-data.h"
#include "xattr.h"
#include "tree-log.h"
#include "volumes.h"
#include "compression.h"
#include "locking.h"
#include "free-space-cache.h"
#include "inode-map.h"
#include "backref.h"
#include "hash.h"
#include "props.h"
#include "qgroup.h"
struct btrfs_iget_args {
struct btrfs_key *location;
struct btrfs_root *root;
};
struct btrfs_dio_data {
u64 outstanding_extents;
u64 reserve;
u64 unsubmitted_oe_range_start;
u64 unsubmitted_oe_range_end;
};
static const struct inode_operations btrfs_dir_inode_operations;
static const struct inode_operations btrfs_symlink_inode_operations;
static const struct inode_operations btrfs_dir_ro_inode_operations;
static const struct inode_operations btrfs_special_inode_operations;
static const struct inode_operations btrfs_file_inode_operations;
static const struct address_space_operations btrfs_aops;
static const struct address_space_operations btrfs_symlink_aops;
static const struct file_operations btrfs_dir_file_operations;
static const struct extent_io_ops btrfs_extent_io_ops;
static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_transaction_cachep;
struct kmem_cache *btrfs_path_cachep;
struct kmem_cache *btrfs_free_space_cachep;
#define S_SHIFT 12
static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
[S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
[S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
[S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
[S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
[S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
[S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
[S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
};
static int btrfs_setsize(struct inode *inode, struct iattr *attr);
static int btrfs_truncate(struct inode *inode);
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
static noinline int cow_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock);
static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
u64 len, u64 orig_start,
u64 block_start, u64 block_len,
u64 orig_block_len, u64 ram_bytes,
int type);
static int btrfs_dirty_inode(struct inode *inode);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_inode_set_ops(struct inode *inode)
{
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
}
#endif
static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
struct inode *inode, struct inode *dir,
const struct qstr *qstr)
{
int err;
err = btrfs_init_acl(trans, inode, dir);
if (!err)
err = btrfs_xattr_security_init(trans, inode, dir, qstr);
return err;
}
/*
* this does all the hard work for inserting an inline extent into
* the btree. The caller should have done a btrfs_drop_extents so that
* no overlapping inline items exist in the btree
*/
static int insert_inline_extent(struct btrfs_trans_handle *trans,
struct btrfs_path *path, int extent_inserted,
struct btrfs_root *root, struct inode *inode,
u64 start, size_t size, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct extent_buffer *leaf;
struct page *page = NULL;
char *kaddr;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
int err = 0;
int ret;
size_t cur_size = size;
unsigned long offset;
if (compressed_size && compressed_pages)
cur_size = compressed_size;
inode_add_bytes(inode, size);
if (!extent_inserted) {
struct btrfs_key key;
size_t datasize;
key.objectid = btrfs_ino(inode);
key.offset = start;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(cur_size);
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (ret) {
err = ret;
goto fail;
}
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, size);
ptr = btrfs_file_extent_inline_start(ei);
if (compress_type != BTRFS_COMPRESS_NONE) {
struct page *cpage;
int i = 0;
while (compressed_size > 0) {
cpage = compressed_pages[i];
cur_size = min_t(unsigned long, compressed_size,
PAGE_SIZE);
kaddr = kmap_atomic(cpage);
write_extent_buffer(leaf, kaddr, ptr, cur_size);
kunmap_atomic(kaddr);
i++;
ptr += cur_size;
compressed_size -= cur_size;
}
btrfs_set_file_extent_compression(leaf, ei,
compress_type);
} else {
page = find_get_page(inode->i_mapping,
start >> PAGE_SHIFT);
btrfs_set_file_extent_compression(leaf, ei, 0);
kaddr = kmap_atomic(page);
offset = start & (PAGE_SIZE - 1);
write_extent_buffer(leaf, kaddr + offset, ptr, size);
kunmap_atomic(kaddr);
put_page(page);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
/*
* we're an inline extent, so nobody can
* extend the file past i_size without locking
* a page we already have locked.
*
* We must do any isize and inode updates
* before we unlock the pages. Otherwise we
* could end up racing with unlink.
*/
BTRFS_I(inode)->disk_i_size = inode->i_size;
ret = btrfs_update_inode(trans, root, inode);
return ret;
fail:
return err;
}
/*
* conditionally insert an inline extent into the file. This
* does the checks required to make sure the data is small enough
* to fit as an inline extent.
*/
static noinline int cow_file_range_inline(struct btrfs_root *root,
struct inode *inode, u64 start,
u64 end, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct btrfs_trans_handle *trans;
u64 isize = i_size_read(inode);
u64 actual_end = min(end + 1, isize);
u64 inline_len = actual_end - start;
u64 aligned_end = ALIGN(end, root->sectorsize);
u64 data_len = inline_len;
int ret;
struct btrfs_path *path;
int extent_inserted = 0;
u32 extent_item_size;
if (compressed_size)
data_len = compressed_size;
if (start > 0 ||
actual_end > root->sectorsize ||
data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
(!compressed_size &&
(actual_end & (root->sectorsize - 1)) == 0) ||
end + 1 < isize ||
data_len > root->fs_info->max_inline) {
return 1;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
if (compressed_size && compressed_pages)
extent_item_size = btrfs_file_extent_calc_inline_size(
compressed_size);
else
extent_item_size = btrfs_file_extent_calc_inline_size(
inline_len);
ret = __btrfs_drop_extents(trans, root, inode, path,
start, aligned_end, NULL,
1, 1, extent_item_size, &extent_inserted);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out;
}
if (isize > actual_end)
inline_len = min_t(u64, isize, actual_end);
ret = insert_inline_extent(trans, path, extent_inserted,
root, inode, start,
inline_len, compressed_size,
compress_type, compressed_pages);
if (ret && ret != -ENOSPC) {
btrfs_abort_transaction(trans, root, ret);
goto out;
} else if (ret == -ENOSPC) {
ret = 1;
goto out;
}
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
btrfs_delalloc_release_metadata(inode, end + 1 - start);
btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
out:
/*
* Don't forget to free the reserved space, as for inlined extent
* it won't count as data extent, free them directly here.
* And at reserve time, it's always aligned to page size, so
* just free one page here.
*/
btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
btrfs_free_path(path);
btrfs_end_transaction(trans, root);
return ret;
}
struct async_extent {
u64 start;
u64 ram_size;
u64 compressed_size;
struct page **pages;
unsigned long nr_pages;
int compress_type;
struct list_head list;
};
struct async_cow {
struct inode *inode;
struct btrfs_root *root;
struct page *locked_page;
u64 start;
u64 end;
struct list_head extents;
struct btrfs_work work;
};
static noinline int add_async_extent(struct async_cow *cow,
u64 start, u64 ram_size,
u64 compressed_size,
struct page **pages,
unsigned long nr_pages,
int compress_type)
{
struct async_extent *async_extent;
async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
BUG_ON(!async_extent); /* -ENOMEM */
async_extent->start = start;
async_extent->ram_size = ram_size;
async_extent->compressed_size = compressed_size;
async_extent->pages = pages;
async_extent->nr_pages = nr_pages;
async_extent->compress_type = compress_type;
list_add_tail(&async_extent->list, &cow->extents);
return 0;
}
static inline int inode_need_compress(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
/* force compress */
if (btrfs_test_opt(root, FORCE_COMPRESS))
return 1;
/* bad compression ratios */
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
return 0;
if (btrfs_test_opt(root, COMPRESS) ||
BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
BTRFS_I(inode)->force_compress)
return 1;
return 0;
}
/*
* we create compressed extents in two phases. The first
* phase compresses a range of pages that have already been
* locked (both pages and state bits are locked).
*
* This is done inside an ordered work queue, and the compression
* is spread across many cpus. The actual IO submission is step
* two, and the ordered work queue takes care of making sure that
* happens in the same order things were put onto the queue by
* writepages and friends.
*
* If this code finds it can't get good compression, it puts an
* entry onto the work queue to write the uncompressed bytes. This
* makes sure that both compressed inodes and uncompressed inodes
* are written in the same order that the flusher thread sent them
* down.
*/
static noinline void compress_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end,
struct async_cow *async_cow,
int *num_added)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 num_bytes;
u64 blocksize = root->sectorsize;
u64 actual_end;
u64 isize = i_size_read(inode);
int ret = 0;
struct page **pages = NULL;
unsigned long nr_pages;
unsigned long nr_pages_ret = 0;
unsigned long total_compressed = 0;
unsigned long total_in = 0;
unsigned long max_compressed = SZ_128K;
unsigned long max_uncompressed = SZ_128K;
int i;
int will_compress;
int compress_type = root->fs_info->compress_type;
int redirty = 0;
/* if this is a small write inside eof, kick off a defrag */
if ((end - start + 1) < SZ_16K &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
btrfs_add_inode_defrag(NULL, inode);
actual_end = min_t(u64, isize, end + 1);
again:
will_compress = 0;
nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
/*
* we don't want to send crud past the end of i_size through
* compression, that's just a waste of CPU time. So, if the
* end of the file is before the start of our current
* requested range of bytes, we bail out to the uncompressed
* cleanup code that can deal with all of this.
*
* It isn't really the fastest way to fix things, but this is a
* very uncommon corner.
*/
if (actual_end <= start)
goto cleanup_and_bail_uncompressed;
total_compressed = actual_end - start;
/*
* skip compression for a small file range(<=blocksize) that
* isn't an inline extent, since it dosen't save disk space at all.
*/
if (total_compressed <= blocksize &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
goto cleanup_and_bail_uncompressed;
/* we want to make sure that amount of ram required to uncompress
* an extent is reasonable, so we limit the total size in ram
* of a compressed extent to 128k. This is a crucial number
* because it also controls how easily we can spread reads across
* cpus for decompression.
*
* We also want to make sure the amount of IO required to do
* a random read is reasonably small, so we limit the size of
* a compressed extent to 128k.
*/
total_compressed = min(total_compressed, max_uncompressed);
num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
total_in = 0;
ret = 0;
/*
* we do compression for mount -o compress and when the
* inode has not been flagged as nocompress. This flag can
* change at any time if we discover bad compression ratios.
*/
if (inode_need_compress(inode)) {
WARN_ON(pages);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages) {
/* just bail out to the uncompressed code */
goto cont;
}
if (BTRFS_I(inode)->force_compress)
compress_type = BTRFS_I(inode)->force_compress;
/*
* we need to call clear_page_dirty_for_io on each
* page in the range. Otherwise applications with the file
* mmap'd can wander in and change the page contents while
* we are compressing them.
*
* If the compression fails for any reason, we set the pages
* dirty again later on.
*/
extent_range_clear_dirty_for_io(inode, start, end);
redirty = 1;
ret = btrfs_compress_pages(compress_type,
inode->i_mapping, start,
total_compressed, pages,
nr_pages, &nr_pages_ret,
&total_in,
&total_compressed,
max_compressed);
if (!ret) {
unsigned long offset = total_compressed &
(PAGE_SIZE - 1);
struct page *page = pages[nr_pages_ret - 1];
char *kaddr;
/* zero the tail end of the last page, we might be
* sending it down to disk
*/
if (offset) {
kaddr = kmap_atomic(page);
memset(kaddr + offset, 0,
PAGE_SIZE - offset);
kunmap_atomic(kaddr);
}
will_compress = 1;
}
}
cont:
if (start == 0) {
/* lets try to make an inline extent */
if (ret || total_in < (actual_end - start)) {
/* we didn't compress the entire range, try
* to make an uncompressed inline extent.
*/
ret = cow_file_range_inline(root, inode, start, end,
0, 0, NULL);
} else {
/* try making a compressed inline extent */
ret = cow_file_range_inline(root, inode, start, end,
total_compressed,
compress_type, pages);
}
if (ret <= 0) {
unsigned long clear_flags = EXTENT_DELALLOC |
EXTENT_DEFRAG;
unsigned long page_error_op;
clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
/*
* inline extent creation worked or returned error,
* we don't need to create any more async work items.
* Unlock and free up our temp pages.
*/
extent_clear_unlock_delalloc(inode, start, end, NULL,
clear_flags, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
page_error_op |
PAGE_END_WRITEBACK);
goto free_pages_out;
}
}
if (will_compress) {
/*
* we aren't doing an inline extent round the compressed size
* up to a block size boundary so the allocator does sane
* things
*/
total_compressed = ALIGN(total_compressed, blocksize);
/*
* one last check to make sure the compression is really a
* win, compare the page count read with the blocks on disk
*/
total_in = ALIGN(total_in, PAGE_SIZE);
if (total_compressed >= total_in) {
will_compress = 0;
} else {
num_bytes = total_in;
}
}
if (!will_compress && pages) {
/*
* the compression code ran but failed to make things smaller,
* free any pages it allocated and our page pointer array
*/
for (i = 0; i < nr_pages_ret; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
pages = NULL;
total_compressed = 0;
nr_pages_ret = 0;
/* flag the file so we don't compress in the future */
if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
!(BTRFS_I(inode)->force_compress)) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
}
}
if (will_compress) {
*num_added += 1;
/* the async work queues will take care of doing actual
* allocation on disk for these compressed pages,
* and will submit them to the elevator.
*/
add_async_extent(async_cow, start, num_bytes,
total_compressed, pages, nr_pages_ret,
compress_type);
if (start + num_bytes < end) {
start += num_bytes;
pages = NULL;
cond_resched();
goto again;
}
} else {
cleanup_and_bail_uncompressed:
/*
* No compression, but we still need to write the pages in
* the file we've been given so far. redirty the locked
* page if it corresponds to our extent and set things up
* for the async work queue to run cow_file_range to do
* the normal delalloc dance
*/
if (page_offset(locked_page) >= start &&
page_offset(locked_page) <= end) {
__set_page_dirty_nobuffers(locked_page);
/* unlocked later on in the async handlers */
}
if (redirty)
extent_range_redirty_for_io(inode, start, end);
add_async_extent(async_cow, start, end - start + 1,
0, NULL, 0, BTRFS_COMPRESS_NONE);
*num_added += 1;
}
return;
free_pages_out:
for (i = 0; i < nr_pages_ret; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
}
static void free_async_extent_pages(struct async_extent *async_extent)
{
int i;
if (!async_extent->pages)
return;
for (i = 0; i < async_extent->nr_pages; i++) {
WARN_ON(async_extent->pages[i]->mapping);
put_page(async_extent->pages[i]);
}
kfree(async_extent->pages);
async_extent->nr_pages = 0;
async_extent->pages = NULL;
}
/*
* phase two of compressed writeback. This is the ordered portion
* of the code, which only gets called in the order the work was
* queued. We walk all the async extents created by compress_file_range
* and send them down to the disk.
*/
static noinline void submit_compressed_extents(struct inode *inode,
struct async_cow *async_cow)
{
struct async_extent *async_extent;
u64 alloc_hint = 0;
struct btrfs_key ins;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree;
int ret = 0;
again:
while (!list_empty(&async_cow->extents)) {
async_extent = list_entry(async_cow->extents.next,
struct async_extent, list);
list_del(&async_extent->list);
io_tree = &BTRFS_I(inode)->io_tree;
retry:
/* did the compression code fall back to uncompressed IO? */
if (!async_extent->pages) {
int page_started = 0;
unsigned long nr_written = 0;
lock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
/* allocate blocks */
ret = cow_file_range(inode, async_cow->locked_page,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
&page_started, &nr_written, 0);
/* JDM XXX */
/*
* if page_started, cow_file_range inserted an
* inline extent and took care of all the unlocking
* and IO for us. Otherwise, we need to submit
* all those pages down to the drive.
*/
if (!page_started && !ret)
extent_write_locked_range(io_tree,
inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
btrfs_get_extent,
WB_SYNC_ALL);
else if (ret)
unlock_page(async_cow->locked_page);
kfree(async_extent);
cond_resched();
continue;
}
lock_extent(io_tree, async_extent->start,
async_extent->start + async_extent->ram_size - 1);
ret = btrfs_reserve_extent(root,
async_extent->compressed_size,
async_extent->compressed_size,
0, alloc_hint, &ins, 1, 1);
if (ret) {
free_async_extent_pages(async_extent);
if (ret == -ENOSPC) {
unlock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
/*
* we need to redirty the pages if we decide to
* fallback to uncompressed IO, otherwise we
* will not submit these pages down to lower
* layers.
*/
extent_range_redirty_for_io(inode,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
goto retry;
}
goto out_free;
}
/*
* here we're doing allocation and writeback of the
* compressed pages
*/
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
em = alloc_extent_map();
if (!em) {
ret = -ENOMEM;
goto out_free_reserve;
}
em->start = async_extent->start;
em->len = async_extent->ram_size;
em->orig_start = em->start;
em->mod_start = em->start;
em->mod_len = em->len;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = async_extent->ram_size;
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->compress_type = async_extent->compress_type;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
em->generation = -1;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
}
if (ret)
goto out_free_reserve;
ret = btrfs_add_ordered_extent_compress(inode,
async_extent->start,
ins.objectid,
async_extent->ram_size,
ins.offset,
BTRFS_ORDERED_COMPRESSED,
async_extent->compress_type);
if (ret) {
btrfs_drop_extent_cache(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
goto out_free_reserve;
}
/*
* clear dirty, set writeback and unlock the pages.
*/
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK);
ret = btrfs_submit_compressed_write(inode,
async_extent->start,
async_extent->ram_size,
ins.objectid,
ins.offset, async_extent->pages,
async_extent->nr_pages);
if (ret) {
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
struct page *p = async_extent->pages[0];
const u64 start = async_extent->start;
const u64 end = start + async_extent->ram_size - 1;
p->mapping = inode->i_mapping;
tree->ops->writepage_end_io_hook(p, start, end,
NULL, 0);
p->mapping = NULL;
extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
}
alloc_hint = ins.objectid + ins.offset;
kfree(async_extent);
cond_resched();
}
return;
out_free_reserve:
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
out_free:
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
kfree(async_extent);
goto again;
}
static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
u64 num_bytes)
{
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
u64 alloc_hint = 0;
read_lock(&em_tree->lock);
em = search_extent_mapping(em_tree, start, num_bytes);
if (em) {
/*
* if block start isn't an actual block number then find the
* first block in this inode and use that as a hint. If that
* block is also bogus then just don't worry about it.
*/
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
free_extent_map(em);
em = search_extent_mapping(em_tree, 0, 0);
if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
alloc_hint = em->block_start;
if (em)
free_extent_map(em);
} else {
alloc_hint = em->block_start;
free_extent_map(em);
}
}
read_unlock(&em_tree->lock);
return alloc_hint;
}
/*
* when extent_io.c finds a delayed allocation range in the file,
* the call backs end up in this code. The basic idea is to
* allocate extents on disk for the range, and create ordered data structs
* in ram to track those extents.
*
* locked_page is the page that writepage had locked already. We use
* it to make sure we don't do extra locks or unlocks.
*
* *page_started is set to one if we unlock locked_page and do everything
* required to start IO on it. It may be clean and already done with
* IO when we return.
*/
static noinline int cow_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written,
int unlock)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 alloc_hint = 0;
u64 num_bytes;
unsigned long ram_size;
u64 disk_num_bytes;
u64 cur_alloc_size;
u64 blocksize = root->sectorsize;
struct btrfs_key ins;
struct extent_map *em;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
int ret = 0;
if (btrfs_is_free_space_inode(inode)) {
WARN_ON_ONCE(1);
ret = -EINVAL;
goto out_unlock;
}
num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
disk_num_bytes = num_bytes;
/* if this is a small write inside eof, kick off defrag */
if (num_bytes < SZ_64K &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
btrfs_add_inode_defrag(NULL, inode);
if (start == 0) {
/* lets try to make an inline extent */
ret = cow_file_range_inline(root, inode, start, end, 0, 0,
NULL);
if (ret == 0) {
extent_clear_unlock_delalloc(inode, start, end, NULL,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
*nr_written = *nr_written +
(end - start + PAGE_SIZE) / PAGE_SIZE;
*page_started = 1;
goto out;
} else if (ret < 0) {
goto out_unlock;
}
}
BUG_ON(disk_num_bytes >
btrfs_super_total_bytes(root->fs_info->super_copy));
alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
while (disk_num_bytes > 0) {
unsigned long op;
cur_alloc_size = disk_num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size,
root->sectorsize, 0, alloc_hint,
&ins, 1, 1);
if (ret < 0)
goto out_unlock;
em = alloc_extent_map();
if (!em) {
ret = -ENOMEM;
goto out_reserve;
}
em->start = start;
em->orig_start = em->start;
ram_size = ins.offset;
em->len = ins.offset;
em->mod_start = em->start;
em->mod_len = em->len;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = ram_size;
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
em->generation = -1;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, start,
start + ram_size - 1, 0);
}
if (ret)
goto out_reserve;
cur_alloc_size = ins.offset;
ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
ram_size, cur_alloc_size, 0);
if (ret)
goto out_drop_extent_cache;
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, start,
cur_alloc_size);
if (ret)
goto out_drop_extent_cache;
}
if (disk_num_bytes < cur_alloc_size)
break;
/* we're not doing compressed IO, don't unlock the first
* page (which the caller expects to stay locked), don't
* clear any dirty bits and don't set any writeback bits
*
* Do set the Private2 bit so we know this page was properly
* setup for writepage
*/
op = unlock ? PAGE_UNLOCK : 0;
op |= PAGE_SET_PRIVATE2;
extent_clear_unlock_delalloc(inode, start,
start + ram_size - 1, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC,
op);
disk_num_bytes -= cur_alloc_size;
num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
}
out:
return ret;
out_drop_extent_cache:
btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
out_reserve:
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
out_unlock:
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
EXTENT_DELALLOC | EXTENT_DEFRAG,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
goto out;
}
/*
* work queue call back to started compression on a file and pages
*/
static noinline void async_cow_start(struct btrfs_work *work)
{
struct async_cow *async_cow;
int num_added = 0;
async_cow = container_of(work, struct async_cow, work);
compress_file_range(async_cow->inode, async_cow->locked_page,
async_cow->start, async_cow->end, async_cow,
&num_added);
if (num_added == 0) {
btrfs_add_delayed_iput(async_cow->inode);
async_cow->inode = NULL;
}
}
/*
* work queue call back to submit previously compressed pages
*/
static noinline void async_cow_submit(struct btrfs_work *work)
{
struct async_cow *async_cow;
struct btrfs_root *root;
unsigned long nr_pages;
async_cow = container_of(work, struct async_cow, work);
root = async_cow->root;
nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
PAGE_SHIFT;
/*
* atomic_sub_return implies a barrier for waitqueue_active
*/
if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
5 * SZ_1M &&
waitqueue_active(&root->fs_info->async_submit_wait))
wake_up(&root->fs_info->async_submit_wait);
if (async_cow->inode)
submit_compressed_extents(async_cow->inode, async_cow);
}
static noinline void async_cow_free(struct btrfs_work *work)
{
struct async_cow *async_cow;
async_cow = container_of(work, struct async_cow, work);
if (async_cow->inode)
btrfs_add_delayed_iput(async_cow->inode);
kfree(async_cow);
}
static int cow_file_range_async(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
struct async_cow *async_cow;
struct btrfs_root *root = BTRFS_I(inode)->root;
unsigned long nr_pages;
u64 cur_end;
int limit = 10 * SZ_1M;
clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1, 0, NULL, GFP_NOFS);
while (start < end) {
async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
BUG_ON(!async_cow); /* -ENOMEM */
async_cow->inode = igrab(inode);
async_cow->root = root;
async_cow->locked_page = locked_page;
async_cow->start = start;
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
!btrfs_test_opt(root, FORCE_COMPRESS))
cur_end = end;
else
cur_end = min(end, start + SZ_512K - 1);
async_cow->end = cur_end;
INIT_LIST_HEAD(&async_cow->extents);
btrfs_init_work(&async_cow->work,
btrfs_delalloc_helper,
async_cow_start, async_cow_submit,
async_cow_free);
nr_pages = (cur_end - start + PAGE_SIZE) >>
PAGE_SHIFT;
atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
btrfs_queue_work(root->fs_info->delalloc_workers,
&async_cow->work);
if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->async_delalloc_pages) <
limit));
}
while (atomic_read(&root->fs_info->async_submit_draining) &&
atomic_read(&root->fs_info->async_delalloc_pages)) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->async_delalloc_pages) ==
0));
}
*nr_written += nr_pages;
start = cur_end + 1;
}
*page_started = 1;
return 0;
}
static noinline int csum_exist_in_range(struct btrfs_root *root,
u64 bytenr, u64 num_bytes)
{
int ret;
struct btrfs_ordered_sum *sums;
LIST_HEAD(list);
ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
bytenr + num_bytes - 1, &list, 0);
if (ret == 0 && list_empty(&list))
return 0;
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
list_del(&sums->list);
kfree(sums);
}
return 1;
}
/*
* when nowcow writeback call back. This checks for snapshots or COW copies
* of the extents that exist in the file, and COWs the file as required.
*
* If no cow copies or snapshots exist, we write directly to the existing
* blocks on disk
*/
static noinline int run_delalloc_nocow(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started, int force,
unsigned long *nr_written)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct extent_buffer *leaf;
struct btrfs_path *path;
struct btrfs_file_extent_item *fi;
struct btrfs_key found_key;
u64 cow_start;
u64 cur_offset;
u64 extent_end;
u64 extent_offset;
u64 disk_bytenr;
u64 num_bytes;
u64 disk_num_bytes;
u64 ram_bytes;
int extent_type;
int ret, err;
int type;
int nocow;
int check_prev = 1;
bool nolock;
u64 ino = btrfs_ino(inode);
path = btrfs_alloc_path();
if (!path) {
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
return -ENOMEM;
}
nolock = btrfs_is_free_space_inode(inode);
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
btrfs_free_path(path);
return PTR_ERR(trans);
}
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
cow_start = (u64)-1;
cur_offset = start;
while (1) {
ret = btrfs_lookup_file_extent(trans, root, path, ino,
cur_offset, 0);
if (ret < 0)
goto error;
if (ret > 0 && path->slots[0] > 0 && check_prev) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0] - 1);
if (found_key.objectid == ino &&
found_key.type == BTRFS_EXTENT_DATA_KEY)
path->slots[0]--;
}
check_prev = 0;
next_slot:
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto error;
if (ret > 0)
break;
leaf = path->nodes[0];
}
nocow = 0;
disk_bytenr = 0;
num_bytes = 0;
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid > ino)
break;
if (WARN_ON_ONCE(found_key.objectid < ino) ||
found_key.type < BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
goto next_slot;
}
if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
found_key.offset > end)
break;
if (found_key.offset > cur_offset) {
extent_end = found_key.offset;
extent_type = 0;
goto out_check;
}
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
extent_offset = btrfs_file_extent_offset(leaf, fi);
extent_end = found_key.offset +
btrfs_file_extent_num_bytes(leaf, fi);
disk_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf, fi);
if (extent_end <= start) {
path->slots[0]++;
goto next_slot;
}
if (disk_bytenr == 0)
goto out_check;
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out_check;
if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
goto out_check;
if (btrfs_extent_readonly(root, disk_bytenr))
goto out_check;
if (btrfs_cross_ref_exist(trans, root, ino,
found_key.offset -
extent_offset, disk_bytenr))
goto out_check;
disk_bytenr += extent_offset;
disk_bytenr += cur_offset - found_key.offset;
num_bytes = min(end + 1, extent_end) - cur_offset;
/*
* if there are pending snapshots for this root,
* we fall into common COW way.
*/
if (!nolock) {
err = btrfs_start_write_no_snapshoting(root);
if (!err)
goto out_check;
}
/*
* force cow if csum exists in the range.
* this ensure that csum for a given extent are
* either valid or do not exist.
*/
if (csum_exist_in_range(root, disk_bytenr, num_bytes))
goto out_check;
nocow = 1;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = found_key.offset +
btrfs_file_extent_inline_len(leaf,
path->slots[0], fi);
extent_end = ALIGN(extent_end, root->sectorsize);
} else {
BUG_ON(1);
}
out_check:
if (extent_end <= start) {
path->slots[0]++;
if (!nolock && nocow)
btrfs_end_write_no_snapshoting(root);
goto next_slot;
}
if (!nocow) {
if (cow_start == (u64)-1)
cow_start = cur_offset;
cur_offset = extent_end;
if (cur_offset > end)
break;
path->slots[0]++;
goto next_slot;
}
btrfs_release_path(path);
if (cow_start != (u64)-1) {
ret = cow_file_range(inode, locked_page,
cow_start, found_key.offset - 1,
page_started, nr_written, 1);
if (ret) {
if (!nolock && nocow)
btrfs_end_write_no_snapshoting(root);
goto error;
}
cow_start = (u64)-1;
}
if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
struct extent_map *em;
struct extent_map_tree *em_tree;
em_tree = &BTRFS_I(inode)->extent_tree;
em = alloc_extent_map();
BUG_ON(!em); /* -ENOMEM */
em->start = cur_offset;
em->orig_start = found_key.offset - extent_offset;
em->len = num_bytes;
em->block_len = num_bytes;
em->block_start = disk_bytenr;
em->orig_block_len = disk_num_bytes;
em->ram_bytes = ram_bytes;
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->mod_start = em->start;
em->mod_len = em->len;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
set_bit(EXTENT_FLAG_FILLING, &em->flags);
em->generation = -1;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST) {
free_extent_map(em);
break;
}
btrfs_drop_extent_cache(inode, em->start,
em->start + em->len - 1, 0);
}
type = BTRFS_ORDERED_PREALLOC;
} else {
type = BTRFS_ORDERED_NOCOW;
}
ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
num_bytes, num_bytes, type);
BUG_ON(ret); /* -ENOMEM */
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, cur_offset,
num_bytes);
if (ret) {
if (!nolock && nocow)
btrfs_end_write_no_snapshoting(root);
goto error;
}
}
extent_clear_unlock_delalloc(inode, cur_offset,
cur_offset + num_bytes - 1,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC, PAGE_UNLOCK |
PAGE_SET_PRIVATE2);
if (!nolock && nocow)
btrfs_end_write_no_snapshoting(root);
cur_offset = extent_end;
if (cur_offset > end)
break;
}
btrfs_release_path(path);
if (cur_offset <= end && cow_start == (u64)-1) {
cow_start = cur_offset;
cur_offset = end;
}
if (cow_start != (u64)-1) {
ret = cow_file_range(inode, locked_page, cow_start, end,
page_started, nr_written, 1);
if (ret)
goto error;
}
error:
err = btrfs_end_transaction(trans, root);
if (!ret)
ret = err;
if (ret && cur_offset < end)
extent_clear_unlock_delalloc(inode, cur_offset, end,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
btrfs_free_path(path);
return ret;
}
static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
{
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
!(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
return 0;
/*
* @defrag_bytes is a hint value, no spinlock held here,
* if is not zero, it means the file is defragging.
* Force cow if given extent needs to be defragged.
*/
if (BTRFS_I(inode)->defrag_bytes &&
test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
EXTENT_DEFRAG, 0, NULL))
return 1;
return 0;
}
/*
* extent_io.c call back to do delayed allocation processing
*/
static int run_delalloc_range(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
int ret;
int force_cow = need_force_cow(inode, start, end);
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 1, nr_written);
} else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
} else if (!inode_need_compress(inode)) {
ret = cow_file_range(inode, locked_page, start, end,
page_started, nr_written, 1);
} else {
set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags);
ret = cow_file_range_async(inode, locked_page, start, end,
page_started, nr_written);
}
return ret;
}
static void btrfs_split_extent_hook(struct inode *inode,
struct extent_state *orig, u64 split)
{
u64 size;
/* not delalloc, ignore it */
if (!(orig->state & EXTENT_DELALLOC))
return;
size = orig->end - orig->start + 1;
if (size > BTRFS_MAX_EXTENT_SIZE) {
u64 num_extents;
u64 new_size;
/*
* See the explanation in btrfs_merge_extent_hook, the same
* applies here, just in reverse.
*/
new_size = orig->end - split + 1;
num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
new_size = split - orig->start;
num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE) >= num_extents)
return;
}
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* extent_io.c merge_extent_hook, used to track merged delayed allocation
* extents so we can keep track of new extents that are just merged onto old
* extents, such as when we are doing sequential writes, so we can properly
* account for the metadata space we'll need.
*/
static void btrfs_merge_extent_hook(struct inode *inode,
struct extent_state *new,
struct extent_state *other)
{
u64 new_size, old_size;
u64 num_extents;
/* not delalloc, ignore it */
if (!(other->state & EXTENT_DELALLOC))
return;
if (new->start > other->start)
new_size = new->end - other->start + 1;
else
new_size = other->end - new->start + 1;
/* we're not bigger than the max, unreserve the space and go */
if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents--;
spin_unlock(&BTRFS_I(inode)->lock);
return;
}
/*
* We have to add up either side to figure out how many extents were
* accounted for before we merged into one big extent. If the number of
* extents we accounted for is <= the amount we need for the new range
* then we can return, otherwise drop. Think of it like this
*
* [ 4k][MAX_SIZE]
*
* So we've grown the extent by a MAX_SIZE extent, this would mean we
* need 2 outstanding extents, on one side we have 1 and the other side
* we have 1 so they are == and we can return. But in this case
*
* [MAX_SIZE+4k][MAX_SIZE+4k]
*
* Each range on their own accounts for 2 extents, but merged together
* they are only 3 extents worth of accounting, so we need to drop in
* this case.
*/
old_size = other->end - other->start + 1;
num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
old_size = new->end - new->start + 1;
num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE) >= num_extents)
return;
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents--;
spin_unlock(&BTRFS_I(inode)->lock);
}
static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
struct inode *inode)
{
spin_lock(&root->delalloc_lock);
if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
&root->delalloc_inodes);
set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags);
root->nr_delalloc_inodes++;
if (root->nr_delalloc_inodes == 1) {
spin_lock(&root->fs_info->delalloc_root_lock);
BUG_ON(!list_empty(&root->delalloc_root));
list_add_tail(&root->delalloc_root,
&root->fs_info->delalloc_roots);
spin_unlock(&root->fs_info->delalloc_root_lock);
}
}
spin_unlock(&root->delalloc_lock);
}
static void btrfs_del_delalloc_inode(struct btrfs_root *root,
struct inode *inode)
{
spin_lock(&root->delalloc_lock);
if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_del_init(&BTRFS_I(inode)->delalloc_inodes);
clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags);
root->nr_delalloc_inodes--;
if (!root->nr_delalloc_inodes) {
spin_lock(&root->fs_info->delalloc_root_lock);
BUG_ON(list_empty(&root->delalloc_root));
list_del_init(&root->delalloc_root);
spin_unlock(&root->fs_info->delalloc_root_lock);
}
}
spin_unlock(&root->delalloc_lock);
}
/*
* extent_io.c set_bit_hook, used to track delayed allocation
* bytes in this file, and to maintain the list of inodes that
* have pending delalloc work to be done.
*/
static void btrfs_set_bit_hook(struct inode *inode,
struct extent_state *state, unsigned *bits)
{
if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
WARN_ON(1);
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 len = state->end + 1 - state->start;
bool do_list = !btrfs_is_free_space_inode(inode);
if (*bits & EXTENT_FIRST_DELALLOC) {
*bits &= ~EXTENT_FIRST_DELALLOC;
} else {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
}
/* For sanity tests */
if (btrfs_test_is_dummy_root(root))
return;
__percpu_counter_add(&root->fs_info->delalloc_bytes, len,
root->fs_info->delalloc_batch);
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->delalloc_bytes += len;
if (*bits & EXTENT_DEFRAG)
BTRFS_I(inode)->defrag_bytes += len;
if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags))
btrfs_add_delalloc_inodes(root, inode);
spin_unlock(&BTRFS_I(inode)->lock);
}
}
/*
* extent_io.c clear_bit_hook, see set_bit_hook for why
*/
static void btrfs_clear_bit_hook(struct inode *inode,
struct extent_state *state,
unsigned *bits)
{
u64 len = state->end + 1 - state->start;
u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
BTRFS_MAX_EXTENT_SIZE);
spin_lock(&BTRFS_I(inode)->lock);
if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
BTRFS_I(inode)->defrag_bytes -= len;
spin_unlock(&BTRFS_I(inode)->lock);
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
bool do_list = !btrfs_is_free_space_inode(inode);
if (*bits & EXTENT_FIRST_DELALLOC) {
*bits &= ~EXTENT_FIRST_DELALLOC;
} else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents -= num_extents;
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* We don't reserve metadata space for space cache inodes so we
* don't need to call dellalloc_release_metadata if there is an
* error.
*/
if (*bits & EXTENT_DO_ACCOUNTING &&
root != root->fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, len);
/* For sanity tests. */
if (btrfs_test_is_dummy_root(root))
return;
if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
&& do_list && !(state->state & EXTENT_NORESERVE))
btrfs_free_reserved_data_space_noquota(inode,
state->start, len);
__percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
root->fs_info->delalloc_batch);
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->delalloc_bytes -= len;
if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags))
btrfs_del_delalloc_inode(root, inode);
spin_unlock(&BTRFS_I(inode)->lock);
}
}
/*
* extent_io.c merge_bio_hook, this must check the chunk tree to make sure
* we don't create bios that span stripes or chunks
*/
int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
size_t size, struct bio *bio,
unsigned long bio_flags)
{
struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
u64 logical = (u64)bio->bi_iter.bi_sector << 9;
u64 length = 0;
u64 map_length;
int ret;
if (bio_flags & EXTENT_BIO_COMPRESSED)
return 0;
length = bio->bi_iter.bi_size;
map_length = length;
ret = btrfs_map_block(root->fs_info, rw, logical,
&map_length, NULL, 0);
/* Will always return 0 with map_multi == NULL */
BUG_ON(ret < 0);
if (map_length < length + size)
return 1;
return 0;
}
/*
* in order to insert checksums into the metadata in large chunks,
* we wait until bio submission time. All the pages in the bio are
* checksummed and sums are attached onto the ordered extent record.
*
* At IO completion time the cums attached on the ordered extent record
* are inserted into the btree
*/
static int __btrfs_submit_bio_start(struct inode *inode, int rw,
struct bio *bio, int mirror_num,
unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
BUG_ON(ret); /* -ENOMEM */
return 0;
}
/*
* in order to insert checksums into the metadata in large chunks,
* we wait until bio submission time. All the pages in the bio are
* checksummed and sums are attached onto the ordered extent record.
*
* At IO completion time the cums attached on the ordered extent record
* are inserted into the btree
*/
static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
int mirror_num, unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
if (ret) {
bio->bi_error = ret;
bio_endio(bio);
}
return ret;
}
/*
* extent_io.c submission hook. This does the right thing for csum calculation
* on write, or reading the csums from the tree before a read
*/
static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
int mirror_num, unsigned long bio_flags,
u64 bio_offset)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
int ret = 0;
int skip_sum;
int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
if (btrfs_is_free_space_inode(inode))
metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
if (!(rw & REQ_WRITE)) {
ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
if (ret)
goto out;
if (bio_flags & EXTENT_BIO_COMPRESSED) {
ret = btrfs_submit_compressed_read(inode, bio,
mirror_num,
bio_flags);
goto out;
} else if (!skip_sum) {
ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
if (ret)
goto out;
}
goto mapit;
} else if (async && !skip_sum) {
/* csum items have already been cloned */
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
goto mapit;
/* we're doing a write, do the async checksumming */
ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
inode, rw, bio, mirror_num,
bio_flags, bio_offset,
__btrfs_submit_bio_start,
__btrfs_submit_bio_done);
goto out;
} else if (!skip_sum) {
ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
if (ret)
goto out;
}
mapit:
ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
out:
if (ret < 0) {
bio->bi_error = ret;
bio_endio(bio);
}
return ret;
}
/*
* given a list of ordered sums record them in the inode. This happens
* at IO completion time based on sums calculated at bio submission time.
*/
static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
struct inode *inode, u64 file_offset,
struct list_head *list)
{
struct btrfs_ordered_sum *sum;
list_for_each_entry(sum, list, list) {
trans->adding_csums = 1;
btrfs_csum_file_blocks(trans,
BTRFS_I(inode)->root->fs_info->csum_root, sum);
trans->adding_csums = 0;
}
return 0;
}
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
struct extent_state **cached_state)
{
WARN_ON((end & (PAGE_SIZE - 1)) == 0);
return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
cached_state, GFP_NOFS);
}
/* see btrfs_writepage_start_hook for details on why this is required */
struct btrfs_writepage_fixup {
struct page *page;
struct btrfs_work work;
};
static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
{
struct btrfs_writepage_fixup *fixup;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct page *page;
struct inode *inode;
u64 page_start;
u64 page_end;
int ret;
fixup = container_of(work, struct btrfs_writepage_fixup, work);
page = fixup->page;
again:
lock_page(page);
if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
ClearPageChecked(page);
goto out_page;
}
inode = page->mapping->host;
page_start = page_offset(page);
page_end = page_offset(page) + PAGE_SIZE - 1;
lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state);
/* already ordered? We're done */
if (PagePrivate2(page))
goto out;
ordered = btrfs_lookup_ordered_range(inode, page_start,
PAGE_SIZE);
if (ordered) {
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
page_end, &cached_state, GFP_NOFS);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
ret = btrfs_delalloc_reserve_space(inode, page_start,
PAGE_SIZE);
if (ret) {
mapping_set_error(page->mapping, ret);
end_extent_writepage(page, ret, page_start, page_end);
ClearPageChecked(page);
goto out;
}
btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
ClearPageChecked(page);
set_page_dirty(page);
out:
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
out_page:
unlock_page(page);
put_page(page);
kfree(fixup);
}
/*
* There are a few paths in the higher layers of the kernel that directly
* set the page dirty bit without asking the filesystem if it is a
* good idea. This causes problems because we want to make sure COW
* properly happens and the data=ordered rules are followed.
*
* In our case any range that doesn't have the ORDERED bit set
* hasn't been properly setup for IO. We kick off an async process
* to fix it up. The async helper will wait for ordered extents, set
* the delalloc bit and make it safe to write the page.
*/
static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
{
struct inode *inode = page->mapping->host;
struct btrfs_writepage_fixup *fixup;
struct btrfs_root *root = BTRFS_I(inode)->root;
/* this page is properly in the ordered list */
if (TestClearPagePrivate2(page))
return 0;
if (PageChecked(page))
return -EAGAIN;
fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
if (!fixup)
return -EAGAIN;
SetPageChecked(page);
get_page(page);
btrfs_init_work(&fixup->work, btrfs_fixup_helper,
btrfs_writepage_fixup_worker, NULL, NULL);
fixup->page = page;
btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
return -EBUSY;
}
static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
struct inode *inode, u64 file_pos,
u64 disk_bytenr, u64 disk_num_bytes,
u64 num_bytes, u64 ram_bytes,
u8 compression, u8 encryption,
u16 other_encoding, int extent_type)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *fi;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key ins;
int extent_inserted = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* we may be replacing one extent in the tree with another.
* The new extent is pinned in the extent map, and we don't want
* to drop it from the cache until it is completely in the btree.
*
* So, tell btrfs_drop_extents to leave this extent in the cache.
* the caller is expected to unpin it and allow it to be merged
* with the others.
*/
ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
file_pos + num_bytes, NULL, 0,
1, sizeof(*fi), &extent_inserted);
if (ret)
goto out;
if (!extent_inserted) {
ins.objectid = btrfs_ino(inode);
ins.offset = file_pos;
ins.type = BTRFS_EXTENT_DATA_KEY;
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, root, path, &ins,
sizeof(*fi));
if (ret)
goto out;
}
leaf = path->nodes[0];
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, fi, trans->transid);
btrfs_set_file_extent_type(leaf, fi, extent_type);
btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
btrfs_set_file_extent_offset(leaf, fi, 0);
btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
btrfs_set_file_extent_compression(leaf, fi, compression);
btrfs_set_file_extent_encryption(leaf, fi, encryption);
btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
inode_add_bytes(inode, num_bytes);
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_alloc_reserved_file_extent(trans, root,
root->root_key.objectid,
btrfs_ino(inode), file_pos,
ram_bytes, &ins);
/*
* Release the reserved range from inode dirty range map, as it is
* already moved into delayed_ref_head
*/
btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
out:
btrfs_free_path(path);
return ret;
}
/* snapshot-aware defrag */
struct sa_defrag_extent_backref {
struct rb_node node;
struct old_sa_defrag_extent *old;
u64 root_id;
u64 inum;
u64 file_pos;
u64 extent_offset;
u64 num_bytes;
u64 generation;
};
struct old_sa_defrag_extent {
struct list_head list;
struct new_sa_defrag_extent *new;
u64 extent_offset;
u64 bytenr;
u64 offset;
u64 len;
int count;
};
struct new_sa_defrag_extent {
struct rb_root root;
struct list_head head;
struct btrfs_path *path;
struct inode *inode;
u64 file_pos;
u64 len;
u64 bytenr;
u64 disk_len;
u8 compress_type;
};
static int backref_comp(struct sa_defrag_extent_backref *b1,
struct sa_defrag_extent_backref *b2)
{
if (b1->root_id < b2->root_id)
return -1;
else if (b1->root_id > b2->root_id)
return 1;
if (b1->inum < b2->inum)
return -1;
else if (b1->inum > b2->inum)
return 1;
if (b1->file_pos < b2->file_pos)
return -1;
else if (b1->file_pos > b2->file_pos)
return 1;
/*
* [------------------------------] ===> (a range of space)
* |<--->| |<---->| =============> (fs/file tree A)
* |<---------------------------->| ===> (fs/file tree B)
*
* A range of space can refer to two file extents in one tree while
* refer to only one file extent in another tree.
*
* So we may process a disk offset more than one time(two extents in A)
* and locate at the same extent(one extent in B), then insert two same
* backrefs(both refer to the extent in B).
*/
return 0;
}
static void backref_insert(struct rb_root *root,
struct sa_defrag_extent_backref *backref)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct sa_defrag_extent_backref *entry;
int ret;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
ret = backref_comp(backref, entry);
if (ret < 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&backref->node, parent, p);
rb_insert_color(&backref->node, root);
}
/*
* Note the backref might has changed, and in this case we just return 0.
*/
static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
void *ctx)
{
struct btrfs_file_extent_item *extent;
struct btrfs_fs_info *fs_info;
struct old_sa_defrag_extent *old = ctx;
struct new_sa_defrag_extent *new = old->new;
struct btrfs_path *path = new->path;
struct btrfs_key key;
struct btrfs_root *root;
struct sa_defrag_extent_backref *backref;
struct extent_buffer *leaf;
struct inode *inode = new->inode;
int slot;
int ret;
u64 extent_offset;
u64 num_bytes;
if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
inum == btrfs_ino(inode))
return 0;
key.objectid = root_id;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
fs_info = BTRFS_I(inode)->root->fs_info;
root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(root)) {
if (PTR_ERR(root) == -ENOENT)
return 0;
WARN_ON(1);
pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
inum, offset, root_id);
return PTR_ERR(root);
}
key.objectid = inum;
key.type = BTRFS_EXTENT_DATA_KEY;
if (offset > (u64)-1 << 32)
key.offset = 0;
else
key.offset = offset;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (WARN_ON(ret < 0))
return ret;
ret = 0;
while (1) {
cond_resched();
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
goto out;
} else if (ret > 0) {
ret = 0;
goto out;
}
continue;
}
path->slots[0]++;
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid > inum)
goto out;
if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
continue;
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
continue;
/*
* 'offset' refers to the exact key.offset,
* NOT the 'offset' field in btrfs_extent_data_ref, ie.
* (key.offset - extent_offset).
*/
if (key.offset != offset)
continue;
extent_offset = btrfs_file_extent_offset(leaf, extent);
num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
if (extent_offset >= old->extent_offset + old->offset +
old->len || extent_offset + num_bytes <=
old->extent_offset + old->offset)
continue;
break;
}
backref = kmalloc(sizeof(*backref), GFP_NOFS);
if (!backref) {
ret = -ENOENT;
goto out;
}
backref->root_id = root_id;
backref->inum = inum;
backref->file_pos = offset;
backref->num_bytes = num_bytes;
backref->extent_offset = extent_offset;
backref->generation = btrfs_file_extent_generation(leaf, extent);
backref->old = old;
backref_insert(&new->root, backref);
old->count++;
out:
btrfs_release_path(path);
WARN_ON(ret);
return ret;
}
static noinline bool record_extent_backrefs(struct btrfs_path *path,
struct new_sa_defrag_extent *new)
{
struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
struct old_sa_defrag_extent *old, *tmp;
int ret;
new->path = path;
list_for_each_entry_safe(old, tmp, &new->head, list) {
ret = iterate_inodes_from_logical(old->bytenr +
old->extent_offset, fs_info,
path, record_one_backref,
old);
if (ret < 0 && ret != -ENOENT)
return false;
/* no backref to be processed for this extent */
if (!old->count) {
list_del(&old->list);
kfree(old);
}
}
if (list_empty(&new->head))
return false;
return true;
}
static int relink_is_mergable(struct extent_buffer *leaf,
struct btrfs_file_extent_item *fi,
struct new_sa_defrag_extent *new)
{
if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
return 0;
if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
return 0;
if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
return 0;
if (btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
return 0;
return 1;
}
/*
* Note the backref might has changed, and in this case we just return 0.
*/
static noinline int relink_extent_backref(struct btrfs_path *path,
struct sa_defrag_extent_backref *prev,
struct sa_defrag_extent_backref *backref)
{
struct btrfs_file_extent_item *extent;
struct btrfs_file_extent_item *item;
struct btrfs_ordered_extent *ordered;
struct btrfs_trans_handle *trans;
struct btrfs_fs_info *fs_info;
struct btrfs_root *root;
struct btrfs_key key;
struct extent_buffer *leaf;
struct old_sa_defrag_extent *old = backref->old;
struct new_sa_defrag_extent *new = old->new;
struct inode *src_inode = new->inode;
struct inode *inode;
struct extent_state *cached = NULL;
int ret = 0;
u64 start;
u64 len;
u64 lock_start;
u64 lock_end;
bool merge = false;
int index;
if (prev && prev->root_id == backref->root_id &&
prev->inum == backref->inum &&
prev->file_pos + prev->num_bytes == backref->file_pos)
merge = true;
/* step 1: get root */
key.objectid = backref->root_id;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
fs_info = BTRFS_I(src_inode)->root->fs_info;
index = srcu_read_lock(&fs_info->subvol_srcu);
root = btrfs_read_fs_root_no_name(fs_info, &key);
if (IS_ERR(root)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
if (PTR_ERR(root) == -ENOENT)
return 0;
return PTR_ERR(root);
}
if (btrfs_root_readonly(root)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
return 0;
}
/* step 2: get inode */
key.objectid = backref->inum;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
inode = btrfs_iget(fs_info->sb, &key, root, NULL);
if (IS_ERR(inode)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
return 0;
}
srcu_read_unlock(&fs_info->subvol_srcu, index);
/* step 3: relink backref */
lock_start = backref->file_pos;
lock_end = backref->file_pos + backref->num_bytes - 1;
lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
&cached);
ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
if (ordered) {
btrfs_put_ordered_extent(ordered);
goto out_unlock;
}
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_unlock;
}
key.objectid = backref->inum;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = backref->file_pos;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
goto out_free_path;
} else if (ret > 0) {
ret = 0;
goto out_free_path;
}
extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_generation(path->nodes[0], extent) !=
backref->generation)
goto out_free_path;
btrfs_release_path(path);
start = backref->file_pos;
if (backref->extent_offset < old->extent_offset + old->offset)
start += old->extent_offset + old->offset -
backref->extent_offset;
len = min(backref->extent_offset + backref->num_bytes,
old->extent_offset + old->offset + old->len);
len -= max(backref->extent_offset, old->extent_offset + old->offset);
ret = btrfs_drop_extents(trans, root, inode, start,
start + len, 1);
if (ret)
goto out_free_path;
again:
key.objectid = btrfs_ino(inode);
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = start;
path->leave_spinning = 1;
if (merge) {
struct btrfs_file_extent_item *fi;
u64 extent_len;
struct btrfs_key found_key;
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto out_free_path;
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_len = btrfs_file_extent_num_bytes(leaf, fi);
if (extent_len + found_key.offset == start &&
relink_is_mergable(leaf, fi, new)) {
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_len + len);
btrfs_mark_buffer_dirty(leaf);
inode_add_bytes(inode, len);
ret = 1;
goto out_free_path;
} else {
merge = false;
btrfs_release_path(path);
goto again;
}
}
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(*extent));
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_free_path;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
btrfs_set_file_extent_num_bytes(leaf, item, len);
btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
btrfs_set_file_extent_generation(leaf, item, trans->transid);
btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
btrfs_set_file_extent_compression(leaf, item, new->compress_type);
btrfs_set_file_extent_encryption(leaf, item, 0);
btrfs_set_file_extent_other_encoding(leaf, item, 0);
btrfs_mark_buffer_dirty(leaf);
inode_add_bytes(inode, len);
btrfs_release_path(path);
ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
new->disk_len, 0,
backref->root_id, backref->inum,
new->file_pos); /* start - extent_offset */
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_free_path;
}
ret = 1;
out_free_path:
btrfs_release_path(path);
path->leave_spinning = 0;
btrfs_end_transaction(trans, root);
out_unlock:
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
&cached, GFP_NOFS);
iput(inode);
return ret;
}
static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
{
struct old_sa_defrag_extent *old, *tmp;
if (!new)
return;
list_for_each_entry_safe(old, tmp, &new->head, list) {
kfree(old);
}
kfree(new);
}
static void relink_file_extents(struct new_sa_defrag_extent *new)
{
struct btrfs_path *path;
struct sa_defrag_extent_backref *backref;
struct sa_defrag_extent_backref *prev = NULL;
struct inode *inode;
struct btrfs_root *root;
struct rb_node *node;
int ret;
inode = new->inode;
root = BTRFS_I(inode)->root;
path = btrfs_alloc_path();
if (!path)
return;
if (!record_extent_backrefs(path, new)) {
btrfs_free_path(path);
goto out;
}
btrfs_release_path(path);
while (1) {
node = rb_first(&new->root);
if (!node)
break;
rb_erase(node, &new->root);
backref = rb_entry(node, struct sa_defrag_extent_backref, node);
ret = relink_extent_backref(path, prev, backref);
WARN_ON(ret < 0);
kfree(prev);
if (ret == 1)
prev = backref;
else
prev = NULL;
cond_resched();
}
kfree(prev);
btrfs_free_path(path);
out:
free_sa_defrag_extent(new);
atomic_dec(&root->fs_info->defrag_running);
wake_up(&root->fs_info->transaction_wait);
}
static struct new_sa_defrag_extent *
record_old_file_extents(struct inode *inode,
struct btrfs_ordered_extent *ordered)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct old_sa_defrag_extent *old;
struct new_sa_defrag_extent *new;
int ret;
new = kmalloc(sizeof(*new), GFP_NOFS);
if (!new)
return NULL;
new->inode = inode;
new->file_pos = ordered->file_offset;
new->len = ordered->len;
new->bytenr = ordered->start;
new->disk_len = ordered->disk_len;
new->compress_type = ordered->compress_type;
new->root = RB_ROOT;
INIT_LIST_HEAD(&new->head);
path = btrfs_alloc_path();
if (!path)
goto out_kfree;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = new->file_pos;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out_free_path;
if (ret > 0 && path->slots[0] > 0)
path->slots[0]--;
/* find out all the old extents for the file range */
while (1) {
struct btrfs_file_extent_item *extent;
struct extent_buffer *l;
int slot;
u64 num_bytes;
u64 offset;
u64 end;
u64 disk_bytenr;
u64 extent_offset;
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out_free_path;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid != btrfs_ino(inode))
break;
if (key.type != BTRFS_EXTENT_DATA_KEY)
break;
if (key.offset >= new->file_pos + new->len)
break;
extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
num_bytes = btrfs_file_extent_num_bytes(l, extent);
if (key.offset + num_bytes < new->file_pos)
goto next;
disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
if (!disk_bytenr)
goto next;
extent_offset = btrfs_file_extent_offset(l, extent);
old = kmalloc(sizeof(*old), GFP_NOFS);
if (!old)
goto out_free_path;
offset = max(new->file_pos, key.offset);
end = min(new->file_pos + new->len, key.offset + num_bytes);
old->bytenr = disk_bytenr;
old->extent_offset = extent_offset;
old->offset = offset - key.offset;
old->len = end - offset;
old->new = new;
old->count = 0;
list_add_tail(&old->list, &new->head);
next:
path->slots[0]++;
cond_resched();
}
btrfs_free_path(path);
atomic_inc(&root->fs_info->defrag_running);
return new;
out_free_path:
btrfs_free_path(path);
out_kfree:
free_sa_defrag_extent(new);
return NULL;
}
static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
u64 start, u64 len)
{
struct btrfs_block_group_cache *cache;
cache = btrfs_lookup_block_group(root->fs_info, start);
ASSERT(cache);
spin_lock(&cache->lock);
cache->delalloc_bytes -= len;
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
}
/* as ordered data IO finishes, this gets called so we can finish
* an ordered extent if the range of bytes in the file it covers are
* fully written.
*/
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
{
struct inode *inode = ordered_extent->inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans = NULL;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_state *cached_state = NULL;
struct new_sa_defrag_extent *new = NULL;
int compress_type = 0;
int ret = 0;
u64 logical_len = ordered_extent->len;
bool nolock;
bool truncated = false;
nolock = btrfs_is_free_space_inode(inode);
if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
ret = -EIO;
goto out;
}
btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len - 1);
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
truncated = true;
logical_len = ordered_extent->truncated_len;
/* Truncated the entire extent, don't bother adding */
if (!logical_len)
goto out;
}
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
/*
* For mwrite(mmap + memset to write) case, we still reserve
* space for NOCOW range.
* As NOCOW won't cause a new delayed ref, just free the space
*/
btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
ordered_extent->len);
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, root, ret);
goto out;
}
lock_extent_bits(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
&cached_state);
ret = test_range_bit(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
EXTENT_DEFRAG, 1, cached_state);
if (ret) {
u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
if (0 && last_snapshot >= BTRFS_I(inode)->generation)
/* the inode is shared */
new = record_old_file_extents(inode, ordered_extent);
clear_extent_bit(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
}
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out_unlock;
}
trans->block_rsv = &root->fs_info->delalloc_block_rsv;
if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
compress_type = ordered_extent->compress_type;
if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
BUG_ON(compress_type);
ret = btrfs_mark_extent_written(trans, inode,
ordered_extent->file_offset,
ordered_extent->file_offset +
logical_len);
} else {
BUG_ON(root == root->fs_info->tree_root);
ret = insert_reserved_file_extent(trans, inode,
ordered_extent->file_offset,
ordered_extent->start,
ordered_extent->disk_len,
logical_len, logical_len,
compress_type, 0, 0,
BTRFS_FILE_EXTENT_REG);
if (!ret)
btrfs_release_delalloc_bytes(root,
ordered_extent->start,
ordered_extent->disk_len);
}
unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
ordered_extent->file_offset, ordered_extent->len,
trans->transid);
if (ret < 0) {
btrfs_abort_transaction(trans, root, ret);
goto out_unlock;
}
add_pending_csums(trans, inode, ordered_extent->file_offset,
&ordered_extent->list);
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) { /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, root, ret);
goto out_unlock;
}
ret = 0;
out_unlock:
unlock_extent_cached(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset +
ordered_extent->len - 1, &cached_state, GFP_NOFS);
out:
if (root != root->fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, ordered_extent->len);
if (trans)
btrfs_end_transaction(trans, root);
if (ret || truncated) {
u64 start, end;
if (truncated)
start = ordered_extent->file_offset + logical_len;
else
start = ordered_extent->file_offset;
end = ordered_extent->file_offset + ordered_extent->len - 1;
clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
/* Drop the cache for the part of the extent we didn't write. */
btrfs_drop_extent_cache(inode, start, end, 0);
/*
* If the ordered extent had an IOERR or something else went
* wrong we need to return the space for this ordered extent
* back to the allocator. We only free the extent in the
* truncated case if we didn't write out the extent at all.
*/
if ((ret || !logical_len) &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
btrfs_free_reserved_extent(root, ordered_extent->start,
ordered_extent->disk_len, 1);
}
/*
* This needs to be done to make sure anybody waiting knows we are done
* updating everything for this ordered extent.
*/
btrfs_remove_ordered_extent(inode, ordered_extent);
/* for snapshot-aware defrag */
if (new) {
if (ret) {
free_sa_defrag_extent(new);
atomic_dec(&root->fs_info->defrag_running);
} else {
relink_file_extents(new);
}
}
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);
return ret;
}
static void finish_ordered_fn(struct btrfs_work *work)
{
struct btrfs_ordered_extent *ordered_extent;
ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
btrfs_finish_ordered_io(ordered_extent);
}
static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
struct extent_state *state, int uptodate)
{
struct inode *inode = page->mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ordered_extent *ordered_extent = NULL;
struct btrfs_workqueue *wq;
btrfs_work_func_t func;
trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
ClearPagePrivate2(page);
if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
end - start + 1, uptodate))
return 0;
if (btrfs_is_free_space_inode(inode)) {
wq = root->fs_info->endio_freespace_worker;
func = btrfs_freespace_write_helper;
} else {
wq = root->fs_info->endio_write_workers;
func = btrfs_endio_write_helper;
}
btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
NULL);
btrfs_queue_work(wq, &ordered_extent->work);
return 0;
}
static int __readpage_endio_check(struct inode *inode,
struct btrfs_io_bio *io_bio,
int icsum, struct page *page,
int pgoff, u64 start, size_t len)
{
char *kaddr;
u32 csum_expected;
u32 csum = ~(u32)0;
csum_expected = *(((u32 *)io_bio->csum) + icsum);
kaddr = kmap_atomic(page);
csum = btrfs_csum_data(kaddr + pgoff, csum, len);
btrfs_csum_final(csum, (char *)&csum);
if (csum != csum_expected)
goto zeroit;
kunmap_atomic(kaddr);
return 0;
zeroit:
btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
"csum failed ino %llu off %llu csum %u expected csum %u",
btrfs_ino(inode), start, csum, csum_expected);
memset(kaddr + pgoff, 1, len);
flush_dcache_page(page);
kunmap_atomic(kaddr);
if (csum_expected == 0)
return 0;
return -EIO;
}
/*
* when reads are done, we need to check csums to verify the data is correct
* if there's a match, we allow the bio to finish. If not, the code in
* extent_io.c will try to find good copies for us.
*/
static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
u64 phy_offset, struct page *page,
u64 start, u64 end, int mirror)
{
size_t offset = start - page_offset(page);
struct inode *inode = page->mapping->host;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_root *root = BTRFS_I(inode)->root;
if (PageChecked(page)) {
ClearPageChecked(page);
return 0;
}
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
return 0;
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
GFP_NOFS);
return 0;
}
phy_offset >>= inode->i_sb->s_blocksize_bits;
return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
start, (size_t)(end - start + 1));
}
void btrfs_add_delayed_iput(struct inode *inode)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_inode *binode = BTRFS_I(inode);
if (atomic_add_unless(&inode->i_count, -1, 1))
return;
spin_lock(&fs_info->delayed_iput_lock);
if (binode->delayed_iput_count == 0) {
ASSERT(list_empty(&binode->delayed_iput));
list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
} else {
binode->delayed_iput_count++;
}
spin_unlock(&fs_info->delayed_iput_lock);
}
void btrfs_run_delayed_iputs(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
spin_lock(&fs_info->delayed_iput_lock);
while (!list_empty(&fs_info->delayed_iputs)) {
struct btrfs_inode *inode;
inode = list_first_entry(&fs_info->delayed_iputs,
struct btrfs_inode, delayed_iput);
if (inode->delayed_iput_count) {
inode->delayed_iput_count--;
list_move_tail(&inode->delayed_iput,
&fs_info->delayed_iputs);
} else {
list_del_init(&inode->delayed_iput);
}
spin_unlock(&fs_info->delayed_iput_lock);
iput(&inode->vfs_inode);
spin_lock(&fs_info->delayed_iput_lock);
}
spin_unlock(&fs_info->delayed_iput_lock);
}
/*
* This is called in transaction commit time. If there are no orphan
* files in the subvolume, it removes orphan item and frees block_rsv
* structure.
*/
void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_block_rsv *block_rsv;
int ret;
if (atomic_read(&root->orphan_inodes) ||
root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
return;
spin_lock(&root->orphan_lock);
if (atomic_read(&root->orphan_inodes)) {
spin_unlock(&root->orphan_lock);
return;
}
if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
spin_unlock(&root->orphan_lock);
return;
}
block_rsv = root->orphan_block_rsv;
root->orphan_block_rsv = NULL;
spin_unlock(&root->orphan_lock);
if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
btrfs_root_refs(&root->root_item) > 0) {
ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
root->root_key.objectid);
if (ret)
btrfs_abort_transaction(trans, root, ret);
else
clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
&root->state);
}
if (block_rsv) {
WARN_ON(block_rsv->size > 0);
btrfs_free_block_rsv(root, block_rsv);
}
}
/*
* This creates an orphan entry for the given inode in case something goes
* wrong in the middle of an unlink/truncate.
*
* NOTE: caller of this function should reserve 5 units of metadata for
* this function.
*/
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *block_rsv = NULL;
int reserve = 0;
int insert = 0;
int ret;
if (!root->orphan_block_rsv) {
block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
if (!block_rsv)
return -ENOMEM;
}
spin_lock(&root->orphan_lock);
if (!root->orphan_block_rsv) {
root->orphan_block_rsv = block_rsv;
} else if (block_rsv) {
btrfs_free_block_rsv(root, block_rsv);
block_rsv = NULL;
}
if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags)) {
#if 0
/*
* For proper ENOSPC handling, we should do orphan
* cleanup when mounting. But this introduces backward
* compatibility issue.
*/
if (!xchg(&root->orphan_item_inserted, 1))
insert = 2;
else
insert = 1;
#endif
insert = 1;
atomic_inc(&root->orphan_inodes);
}
if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
&BTRFS_I(inode)->runtime_flags))
reserve = 1;
spin_unlock(&root->orphan_lock);
/* grab metadata reservation from transaction handle */
if (reserve) {
ret = btrfs_orphan_reserve_metadata(trans, inode);
BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
}
/* insert an orphan item to track this unlinked/truncated file */
if (insert >= 1) {
ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
if (ret) {
atomic_dec(&root->orphan_inodes);
if (reserve) {
clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
&BTRFS_I(inode)->runtime_flags);
btrfs_orphan_release_metadata(inode);
}
if (ret != -EEXIST) {
clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags);
btrfs_abort_transaction(trans, root, ret);
return ret;
}
}
ret = 0;
}
/* insert an orphan item to track subvolume contains orphan files */
if (insert >= 2) {
ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
root->root_key.objectid);
if (ret && ret != -EEXIST) {
btrfs_abort_transaction(trans, root, ret);
return ret;
}
}
return 0;
}
/*
* We have done the truncate/delete so we can go ahead and remove the orphan
* item for this particular inode.
*/
static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int delete_item = 0;
int release_rsv = 0;
int ret = 0;
spin_lock(&root->orphan_lock);
if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags))
delete_item = 1;
if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
&BTRFS_I(inode)->runtime_flags))
release_rsv = 1;
spin_unlock(&root->orphan_lock);
if (delete_item) {
atomic_dec(&root->orphan_inodes);
if (trans)
ret = btrfs_del_orphan_item(trans, root,
btrfs_ino(inode));
}
if (release_rsv)
btrfs_orphan_release_metadata(inode);
return ret;
}
/*
* this cleans up any orphans that may be left on the list from the last use
* of this root.
*/
int btrfs_orphan_cleanup(struct btrfs_root *root)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key, found_key;
struct btrfs_trans_handle *trans;
struct inode *inode;
u64 last_objectid = 0;
int ret = 0, nr_unlink = 0, nr_truncate = 0;
if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
return 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->reada = READA_BACK;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/*
* if ret == 0 means we found what we were searching for, which
* is weird, but possible, so only screw with path if we didn't
* find the key and see if we have stuff that matches
*/
if (ret > 0) {
ret = 0;
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
/* pull out the item */
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* make sure the item matches what we want */
if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
break;
if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
/* release the path since we're done with it */
btrfs_release_path(path);
/*
* this is where we are basically btrfs_lookup, without the
* crossing root thing. we store the inode number in the
* offset of the orphan item.
*/
if (found_key.offset == last_objectid) {
btrfs_err(root->fs_info,
"Error removing orphan entry, stopping orphan cleanup");
ret = -EINVAL;
goto out;
}
last_objectid = found_key.offset;
found_key.objectid = found_key.offset;
found_key.type = BTRFS_INODE_ITEM_KEY;
found_key.offset = 0;
inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
ret = PTR_ERR_OR_ZERO(inode);
if (ret && ret != -ESTALE)
goto out;
if (ret == -ESTALE && root == root->fs_info->tree_root) {
struct btrfs_root *dead_root;
struct btrfs_fs_info *fs_info = root->fs_info;
int is_dead_root = 0;
/*
* this is an orphan in the tree root. Currently these
* could come from 2 sources:
* a) a snapshot deletion in progress
* b) a free space cache inode
* We need to distinguish those two, as the snapshot
* orphan must not get deleted.
* find_dead_roots already ran before us, so if this
* is a snapshot deletion, we should find the root
* in the dead_roots list
*/
spin_lock(&fs_info->trans_lock);
list_for_each_entry(dead_root, &fs_info->dead_roots,
root_list) {
if (dead_root->root_key.objectid ==
found_key.objectid) {
is_dead_root = 1;
break;
}
}
spin_unlock(&fs_info->trans_lock);
if (is_dead_root) {
/* prevent this orphan from being found again */
key.offset = found_key.objectid - 1;
continue;
}
}
/*
* Inode is already gone but the orphan item is still there,
* kill the orphan item.
*/
if (ret == -ESTALE) {
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
btrfs_debug(root->fs_info, "auto deleting %Lu",
found_key.objectid);
ret = btrfs_del_orphan_item(trans, root,
found_key.objectid);
btrfs_end_transaction(trans, root);
if (ret)
goto out;
continue;
}
/*
* add this inode to the orphan list so btrfs_orphan_del does
* the proper thing when we hit it
*/
set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags);
atomic_inc(&root->orphan_inodes);
/* if we have links, this was a truncate, lets do that */
if (inode->i_nlink) {
if (WARN_ON(!S_ISREG(inode->i_mode))) {
iput(inode);
continue;
}
nr_truncate++;
/* 1 for the orphan item deletion. */
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
iput(inode);
ret = PTR_ERR(trans);
goto out;
}
ret = btrfs_orphan_add(trans, inode);
btrfs_end_transaction(trans, root);
if (ret) {
iput(inode);
goto out;
}
ret = btrfs_truncate(inode);
if (ret)
btrfs_orphan_del(NULL, inode);
} else {
nr_unlink++;
}
/* this will do delete_inode and everything for us */
iput(inode);
if (ret)
goto out;
}
/* release the path since we're done with it */
btrfs_release_path(path);
root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
if (root->orphan_block_rsv)
btrfs_block_rsv_release(root, root->orphan_block_rsv,
(u64)-1);
if (root->orphan_block_rsv ||
test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
trans = btrfs_join_transaction(root);
if (!IS_ERR(trans))
btrfs_end_transaction(trans, root);
}
if (nr_unlink)
btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
if (nr_truncate)
btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
out:
if (ret)
btrfs_err(root->fs_info,
"could not do orphan cleanup %d", ret);
btrfs_free_path(path);
return ret;
}
/*
* very simple check to peek ahead in the leaf looking for xattrs. If we
* don't find any xattrs, we know there can't be any acls.
*
* slot is the slot the inode is in, objectid is the objectid of the inode
*/
static noinline int acls_after_inode_item(struct extent_buffer *leaf,
int slot, u64 objectid,
int *first_xattr_slot)
{
u32 nritems = btrfs_header_nritems(leaf);
struct btrfs_key found_key;
static u64 xattr_access = 0;
static u64 xattr_default = 0;
int scanned = 0;
if (!xattr_access) {
xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
strlen(XATTR_NAME_POSIX_ACL_ACCESS));
xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
}
slot++;
*first_xattr_slot = -1;
while (slot < nritems) {
btrfs_item_key_to_cpu(leaf, &found_key, slot);
/* we found a different objectid, there must not be acls */
if (found_key.objectid != objectid)
return 0;
/* we found an xattr, assume we've got an acl */
if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
if (found_key.offset == xattr_access ||
found_key.offset == xattr_default)
return 1;
}
/*
* we found a key greater than an xattr key, there can't
* be any acls later on
*/
if (found_key.type > BTRFS_XATTR_ITEM_KEY)
return 0;
slot++;
scanned++;
/*
* it goes inode, inode backrefs, xattrs, extents,
* so if there are a ton of hard links to an inode there can
* be a lot of backrefs. Don't waste time searching too hard,
* this is just an optimization
*/
if (scanned >= 8)
break;
}
/* we hit the end of the leaf before we found an xattr or
* something larger than an xattr. We have to assume the inode
* has acls
*/
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
return 1;
}
/*
* read an inode from the btree into the in-memory inode
*/
static void btrfs_read_locked_inode(struct inode *inode)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key location;
unsigned long ptr;
int maybe_acls;
u32 rdev;
int ret;
bool filled = false;
int first_xattr_slot;
ret = btrfs_fill_inode(inode, &rdev);
if (!ret)
filled = true;
path = btrfs_alloc_path();
if (!path)
goto make_bad;
memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
if (ret)
goto make_bad;
leaf = path->nodes[0];
if (filled)
goto cache_index;
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(leaf, inode_item);
set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
BTRFS_I(inode)->i_otime.tv_sec =
btrfs_timespec_sec(leaf, &inode_item->otime);
BTRFS_I(inode)->i_otime.tv_nsec =
btrfs_timespec_nsec(leaf, &inode_item->otime);
inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
inode->i_version = btrfs_inode_sequence(leaf, inode_item);
inode->i_generation = BTRFS_I(inode)->generation;
inode->i_rdev = 0;
rdev = btrfs_inode_rdev(leaf, inode_item);
BTRFS_I(inode)->index_cnt = (u64)-1;
BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
cache_index:
/*
* If we were modified in the current generation and evicted from memory
* and then re-read we need to do a full sync since we don't have any
* idea about which extents were modified before we were evicted from
* cache.
*
* This is required for both inode re-read from disk and delayed inode
* in delayed_nodes_tree.
*/
if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
/*
* We don't persist the id of the transaction where an unlink operation
* against the inode was last made. So here we assume the inode might
* have been evicted, and therefore the exact value of last_unlink_trans
* lost, and set it to last_trans to avoid metadata inconsistencies
* between the inode and its parent if the inode is fsync'ed and the log
* replayed. For example, in the scenario:
*
* touch mydir/foo
* ln mydir/foo mydir/bar
* sync
* unlink mydir/bar
* echo 2 > /proc/sys/vm/drop_caches # evicts inode
* xfs_io -c fsync mydir/foo
* <power failure>
* mount fs, triggers fsync log replay
*
* We must make sure that when we fsync our inode foo we also log its
* parent inode, otherwise after log replay the parent still has the
* dentry with the "bar" name but our inode foo has a link count of 1
* and doesn't have an inode ref with the name "bar" anymore.
*
* Setting last_unlink_trans to last_trans is a pessimistic approach,
* but it guarantees correctness at the expense of ocassional full
* transaction commits on fsync if our inode is a directory, or if our
* inode is not a directory, logging its parent unnecessarily.
*/
BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
path->slots[0]++;
if (inode->i_nlink != 1 ||
path->slots[0] >= btrfs_header_nritems(leaf))
goto cache_acl;
btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
if (location.objectid != btrfs_ino(inode))
goto cache_acl;
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
if (location.type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
} else if (location.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
extref);
}
cache_acl:
/*
* try to precache a NULL acl entry for files that don't have
* any xattrs or acls
*/
maybe_acls = acls_after_inode_item(leaf, path->slots[0],
btrfs_ino(inode), &first_xattr_slot);
if (first_xattr_slot != -1) {
path->slots[0] = first_xattr_slot;
ret = btrfs_load_inode_props(inode, path);
if (ret)
btrfs_err(root->fs_info,
"error loading props for ino %llu (root %llu): %d",
btrfs_ino(inode),
root->root_key.objectid, ret);
}
btrfs_free_path(path);
if (!maybe_acls)
cache_no_acl(inode);
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
break;
case S_IFDIR:
inode->i_fop = &btrfs_dir_file_operations;
if (root == root->fs_info->tree_root)
inode->i_op = &btrfs_dir_ro_inode_operations;
else
inode->i_op = &btrfs_dir_inode_operations;
break;
case S_IFLNK:
inode->i_op = &btrfs_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &btrfs_symlink_aops;
break;
default:
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
break;
}
btrfs_update_iflags(inode);
return;
make_bad:
btrfs_free_path(path);
make_bad_inode(inode);
}
/*
* given a leaf and an inode, copy the inode fields into the leaf
*/
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode)
{
struct btrfs_map_token token;
btrfs_init_map_token(&token);
btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
&token);
btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
btrfs_set_token_timespec_sec(leaf, &item->atime,
inode->i_atime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->atime,
inode->i_atime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->mtime,
inode->i_mtime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->mtime,
inode->i_mtime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->ctime,
inode->i_ctime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->ctime,
inode->i_ctime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->otime,
BTRFS_I(inode)->i_otime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->otime,
BTRFS_I(inode)->i_otime.tv_nsec, &token);
btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
&token);
btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
&token);
btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
btrfs_set_token_inode_block_group(leaf, item, 0, &token);
}
/*
* copy everything in the in-memory inode into the btree.
*/
static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
struct btrfs_inode_item *inode_item;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, leaf, inode_item, inode);
btrfs_mark_buffer_dirty(leaf);
btrfs_set_inode_last_trans(trans, inode);
ret = 0;
failed:
btrfs_free_path(path);
return ret;
}
/*
* copy everything in the in-memory inode into the btree.
*/
noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
int ret;
/*
* If the inode is a free space inode, we can deadlock during commit
* if we put it into the delayed code.
*
* The data relocation inode should also be directly updated
* without delay
*/
if (!btrfs_is_free_space_inode(inode)
&& root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
&& !root->fs_info->log_root_recovering) {
btrfs_update_root_times(trans, root);
ret = btrfs_delayed_update_inode(trans, root, inode);
if (!ret)
btrfs_set_inode_last_trans(trans, inode);
return ret;
}
return btrfs_update_inode_item(trans, root, inode);
}
noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
int ret;
ret = btrfs_update_inode(trans, root, inode);
if (ret == -ENOSPC)
return btrfs_update_inode_item(trans, root, inode);
return ret;
}
/*
* unlink helper that gets used here in inode.c and in the tree logging
* recovery code. It remove a link in a directory with a given name, and
* also drops the back refs in the inode to the directory
*/
static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, struct inode *inode,
const char *name, int name_len)
{
struct btrfs_path *path;
int ret = 0;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 index;
u64 ino = btrfs_ino(inode);
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->leave_spinning = 1;
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto err;
}
if (!di) {
ret = -ENOENT;
goto err;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret)
goto err;
btrfs_release_path(path);
/*
* If we don't have dir index, we have to get it by looking up
* the inode ref, since we get the inode ref, remove it directly,
* it is unnecessary to do delayed deletion.
*
* But if we have dir index, needn't search inode ref to get it.
* Since the inode ref is close to the inode item, it is better
* that we delay to delete it, and just do this deletion when
* we update the inode item.
*/
if (BTRFS_I(inode)->dir_index) {
ret = btrfs_delayed_delete_inode_ref(inode);
if (!ret) {
index = BTRFS_I(inode)->dir_index;
goto skip_backref;
}
}
ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
dir_ino, &index);
if (ret) {
btrfs_info(root->fs_info,
"failed to delete reference to %.*s, inode %llu parent %llu",
name_len, name, ino, dir_ino);
btrfs_abort_transaction(trans, root, ret);
goto err;
}
skip_backref:
ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto err;
}
ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
inode, dir_ino);
if (ret != 0 && ret != -ENOENT) {
btrfs_abort_transaction(trans, root, ret);
goto err;
}
ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
dir, index);
if (ret == -ENOENT)
ret = 0;
else if (ret)
btrfs_abort_transaction(trans, root, ret);
err:
btrfs_free_path(path);
if (ret)
goto out;
btrfs_i_size_write(dir, dir->i_size - name_len * 2);
inode_inc_iversion(inode);
inode_inc_iversion(dir);
inode->i_ctime = dir->i_mtime =
dir->i_ctime = current_fs_time(inode->i_sb);
ret = btrfs_update_inode(trans, root, dir);
out:
return ret;
}
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, struct inode *inode,
const char *name, int name_len)
{
int ret;
ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
if (!ret) {
drop_nlink(inode);
ret = btrfs_update_inode(trans, root, inode);
}
return ret;
}
/*
* helper to start transaction for unlink and rmdir.
*
* unlink and rmdir are special in btrfs, they do not always free space, so
* if we cannot make our reservations the normal way try and see if there is
* plenty of slack room in the global reserve to migrate, otherwise we cannot
* allow the unlink to occur.
*/
static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
/*
* 1 for the possible orphan item
* 1 for the dir item
* 1 for the dir index
* 1 for the inode ref
* 1 for the inode
*/
return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_trans_handle *trans;
struct inode *inode = d_inode(dentry);
int ret;
trans = __unlink_start_trans(dir);
if (IS_ERR(trans))
return PTR_ERR(trans);
btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
dentry->d_name.name, dentry->d_name.len);
if (ret)
goto out;
if (inode->i_nlink == 0) {
ret = btrfs_orphan_add(trans, inode);
if (ret)
goto out;
}
out:
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
return ret;
}
int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, u64 objectid,
const char *name, int name_len)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 index;
int ret;
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
if (IS_ERR_OR_NULL(di)) {
if (!di)
ret = -ENOENT;
else
ret = PTR_ERR(di);
goto out;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out;
}
btrfs_release_path(path);
ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
objectid, root->root_key.objectid,
dir_ino, &index, name, name_len);
if (ret < 0) {
if (ret != -ENOENT) {
btrfs_abort_transaction(trans, root, ret);
goto out;
}
di = btrfs_search_dir_index_item(root, path, dir_ino,
name, name_len);
if (IS_ERR_OR_NULL(di)) {
if (!di)
ret = -ENOENT;
else
ret = PTR_ERR(di);
btrfs_abort_transaction(trans, root, ret);
goto out;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
btrfs_release_path(path);
index = key.offset;
}
btrfs_release_path(path);
ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out;
}
btrfs_i_size_write(dir, dir->i_size - name_len * 2);
inode_inc_iversion(dir);
dir->i_mtime = dir->i_ctime = current_fs_time(dir->i_sb);
ret = btrfs_update_inode_fallback(trans, root, dir);
if (ret)
btrfs_abort_transaction(trans, root, ret);
out:
btrfs_free_path(path);
return ret;
}
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
int err = 0;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_trans_handle *trans;
if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
return -EPERM;
trans = __unlink_start_trans(dir);
if (IS_ERR(trans))
return PTR_ERR(trans);
if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
err = btrfs_unlink_subvol(trans, root, dir,
BTRFS_I(inode)->location.objectid,
dentry->d_name.name,
dentry->d_name.len);
goto out;
}
err = btrfs_orphan_add(trans, inode);
if (err)
goto out;
/* now the directory is empty */
err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
dentry->d_name.name, dentry->d_name.len);
if (!err)
btrfs_i_size_write(inode, 0);
out:
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
return err;
}
static int truncate_space_check(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 bytes_deleted)
{
int ret;
/*
* This is only used to apply pressure to the enospc system, we don't
* intend to use this reservation at all.
*/
bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
bytes_deleted *= root->nodesize;
ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
if (!ret) {
trace_btrfs_space_reservation(root->fs_info, "transaction",
trans->transid,
bytes_deleted, 1);
trans->bytes_reserved += bytes_deleted;
}
return ret;
}
static int truncate_inline_extent(struct inode *inode,
struct btrfs_path *path,
struct btrfs_key *found_key,
const u64 item_end,
const u64 new_size)
{
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
struct btrfs_file_extent_item *fi;
u32 size = (u32)(new_size - found_key->offset);
struct btrfs_root *root = BTRFS_I(inode)->root;
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
loff_t offset = new_size;
loff_t page_end = ALIGN(offset, PAGE_SIZE);
/*
* Zero out the remaining of the last page of our inline extent,
* instead of directly truncating our inline extent here - that
* would be much more complex (decompressing all the data, then
* compressing the truncated data, which might be bigger than
* the size of the inline extent, resize the extent, etc).
* We release the path because to get the page we might need to
* read the extent item from disk (data not in the page cache).
*/
btrfs_release_path(path);
return btrfs_truncate_block(inode, offset, page_end - offset,
0);
}
btrfs_set_file_extent_ram_bytes(leaf, fi, size);
size = btrfs_file_extent_calc_inline_size(size);
btrfs_truncate_item(root, path, size, 1);
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
inode_sub_bytes(inode, item_end + 1 - new_size);
return 0;
}
/*
* this can truncate away extent items, csum items and directory items.
* It starts at a high offset and removes keys until it can't find
* any higher than new_size
*
* csum items that cross the new i_size are truncated to the new size
* as well.
*
* min_type is the minimum key type to truncate down to. If set to 0, this
* will kill all the items on this inode, including the INODE_ITEM_KEY.
*/
int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode,
u64 new_size, u32 min_type)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
struct btrfs_key found_key;
u64 extent_start = 0;
u64 extent_num_bytes = 0;
u64 extent_offset = 0;
u64 item_end = 0;
u64 last_size = new_size;
u32 found_type = (u8)-1;
int found_extent;
int del_item;
int pending_del_nr = 0;
int pending_del_slot = 0;
int extent_type = -1;
int ret;
int err = 0;
u64 ino = btrfs_ino(inode);
u64 bytes_deleted = 0;
bool be_nice = 0;
bool should_throttle = 0;
bool should_end = 0;
BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
/*
* for non-free space inodes and ref cows, we want to back off from
* time to time
*/
if (!btrfs_is_free_space_inode(inode) &&
test_bit(BTRFS_ROOT_REF_COWS, &root->state))
be_nice = 1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_BACK;
/*
* We want to drop from the next block forward in case this new size is
* not block aligned since we will be keeping the last block of the
* extent just the way it is.
*/
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
root == root->fs_info->tree_root)
btrfs_drop_extent_cache(inode, ALIGN(new_size,
root->sectorsize), (u64)-1, 0);
/*
* This function is also used to drop the items in the log tree before
* we relog the inode, so if root != BTRFS_I(inode)->root, it means
* it is used to drop the loged items. So we shouldn't kill the delayed
* items.
*/
if (min_type == 0 && root == BTRFS_I(inode)->root)
btrfs_kill_delayed_inode_items(inode);
key.objectid = ino;
key.offset = (u64)-1;
key.type = (u8)-1;
search_again:
/*
* with a 16K leaf size and 128MB extents, you can actually queue
* up a huge file in a single leaf. Most of the time that
* bytes_deleted is > 0, it will be huge by the time we get here
*/
if (be_nice && bytes_deleted > SZ_32M) {
if (btrfs_should_end_transaction(trans, root)) {
err = -EAGAIN;
goto error;
}
}
path->leave_spinning = 1;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0) {
err = ret;
goto out;
}
if (ret > 0) {
/* there are no items in the tree for us to truncate, we're
* done
*/
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
while (1) {
fi = NULL;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = found_key.type;
if (found_key.objectid != ino)
break;
if (found_type < min_type)
break;
item_end = found_key.offset;
if (found_type == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
item_end +=
btrfs_file_extent_num_bytes(leaf, fi);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
item_end += btrfs_file_extent_inline_len(leaf,
path->slots[0], fi);
}
item_end--;
}
if (found_type > min_type) {
del_item = 1;
} else {
if (item_end < new_size)
break;
if (found_key.offset >= new_size)
del_item = 1;
else
del_item = 0;
}
found_extent = 0;
/* FIXME, shrink the extent if the ref count is only 1 */
if (found_type != BTRFS_EXTENT_DATA_KEY)
goto delete;
if (del_item)
last_size = found_key.offset;
else
last_size = new_size;
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
u64 num_dec;
extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
if (!del_item) {
u64 orig_num_bytes =
btrfs_file_extent_num_bytes(leaf, fi);
extent_num_bytes = ALIGN(new_size -
found_key.offset,
root->sectorsize);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_num_bytes);
num_dec = (orig_num_bytes -
extent_num_bytes);
if (test_bit(BTRFS_ROOT_REF_COWS,
&root->state) &&
extent_start != 0)
inode_sub_bytes(inode, num_dec);
btrfs_mark_buffer_dirty(leaf);
} else {
extent_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf,
fi);
extent_offset = found_key.offset -
btrfs_file_extent_offset(leaf, fi);
/* FIXME blocksize != 4096 */
num_dec = btrfs_file_extent_num_bytes(leaf, fi);
if (extent_start != 0) {
found_extent = 1;
if (test_bit(BTRFS_ROOT_REF_COWS,
&root->state))
inode_sub_bytes(inode, num_dec);
}
}
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
/*
* we can't truncate inline items that have had
* special encodings
*/
if (!del_item &&
btrfs_file_extent_encryption(leaf, fi) == 0 &&
btrfs_file_extent_other_encoding(leaf, fi) == 0) {
/*
* Need to release path in order to truncate a
* compressed extent. So delete any accumulated
* extent items so far.
*/
if (btrfs_file_extent_compression(leaf, fi) !=
BTRFS_COMPRESS_NONE && pending_del_nr) {
err = btrfs_del_items(trans, root, path,
pending_del_slot,
pending_del_nr);
if (err) {
btrfs_abort_transaction(trans,
root,
err);
goto error;
}
pending_del_nr = 0;
}
err = truncate_inline_extent(inode, path,
&found_key,
item_end,
new_size);
if (err) {
btrfs_abort_transaction(trans,
root, err);
goto error;
}
} else if (test_bit(BTRFS_ROOT_REF_COWS,
&root->state)) {
inode_sub_bytes(inode, item_end + 1 - new_size);
}
}
delete:
if (del_item) {
if (!pending_del_nr) {
/* no pending yet, add ourselves */
pending_del_slot = path->slots[0];
pending_del_nr = 1;
} else if (pending_del_nr &&
path->slots[0] + 1 == pending_del_slot) {
/* hop on the pending chunk */
pending_del_nr++;
pending_del_slot = path->slots[0];
} else {
BUG();
}
} else {
break;
}
should_throttle = 0;
if (found_extent &&
(test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
root == root->fs_info->tree_root)) {
btrfs_set_path_blocking(path);
bytes_deleted += extent_num_bytes;
ret = btrfs_free_extent(trans, root, extent_start,
extent_num_bytes, 0,
btrfs_header_owner(leaf),
ino, extent_offset);
BUG_ON(ret);
if (btrfs_should_throttle_delayed_refs(trans, root))
btrfs_async_run_delayed_refs(root,
trans->delayed_ref_updates * 2, 0);
if (be_nice) {
if (truncate_space_check(trans, root,
extent_num_bytes)) {
should_end = 1;
}
if (btrfs_should_throttle_delayed_refs(trans,
root)) {
should_throttle = 1;
}
}
}
if (found_type == BTRFS_INODE_ITEM_KEY)
break;
if (path->slots[0] == 0 ||
path->slots[0] != pending_del_slot ||
should_throttle || should_end) {
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path,
pending_del_slot,
pending_del_nr);
if (ret) {
btrfs_abort_transaction(trans,
root, ret);
goto error;
}
pending_del_nr = 0;
}
btrfs_release_path(path);
if (should_throttle) {
unsigned long updates = trans->delayed_ref_updates;
if (updates) {
trans->delayed_ref_updates = 0;
ret = btrfs_run_delayed_refs(trans, root, updates * 2);
if (ret && !err)
err = ret;
}
}
/*
* if we failed to refill our space rsv, bail out
* and let the transaction restart
*/
if (should_end) {
err = -EAGAIN;
goto error;
}
goto search_again;
} else {
path->slots[0]--;
}
}
out:
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path, pending_del_slot,
pending_del_nr);
if (ret)
btrfs_abort_transaction(trans, root, ret);
}
error:
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
btrfs_ordered_update_i_size(inode, last_size, NULL);
btrfs_free_path(path);
if (be_nice && bytes_deleted > SZ_32M) {
unsigned long updates = trans->delayed_ref_updates;
if (updates) {
trans->delayed_ref_updates = 0;
ret = btrfs_run_delayed_refs(trans, root, updates * 2);
if (ret && !err)
err = ret;
}
}
return err;
}
/*
* btrfs_truncate_block - read, zero a chunk and write a block
* @inode - inode that we're zeroing
* @from - the offset to start zeroing
* @len - the length to zero, 0 to zero the entire range respective to the
* offset
* @front - zero up to the offset instead of from the offset on
*
* This will find the block for the "from" offset and cow the block and zero the
* part we want to zero. This is used with truncate and hole punching.
*/
int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
int front)
{
struct address_space *mapping = inode->i_mapping;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
char *kaddr;
u32 blocksize = root->sectorsize;
pgoff_t index = from >> PAGE_SHIFT;
unsigned offset = from & (blocksize - 1);
struct page *page;
gfp_t mask = btrfs_alloc_write_mask(mapping);
int ret = 0;
u64 block_start;
u64 block_end;
if ((offset & (blocksize - 1)) == 0 &&
(!len || ((len & (blocksize - 1)) == 0)))
goto out;
ret = btrfs_delalloc_reserve_space(inode,
round_down(from, blocksize), blocksize);
if (ret)
goto out;
again:
page = find_or_create_page(mapping, index, mask);
if (!page) {
btrfs_delalloc_release_space(inode,
round_down(from, blocksize),
blocksize);
ret = -ENOMEM;
goto out;
}
block_start = round_down(from, blocksize);
block_end = block_start + blocksize - 1;
if (!PageUptodate(page)) {
ret = btrfs_readpage(NULL, page);
lock_page(page);
if (page->mapping != mapping) {
unlock_page(page);
put_page(page);
goto again;
}
if (!PageUptodate(page)) {
ret = -EIO;
goto out_unlock;
}
}
wait_on_page_writeback(page);
lock_extent_bits(io_tree, block_start, block_end, &cached_state);
set_page_extent_mapped(page);
ordered = btrfs_lookup_ordered_extent(inode, block_start);
if (ordered) {
unlock_extent_cached(io_tree, block_start, block_end,
&cached_state, GFP_NOFS);
unlock_page(page);
put_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, &cached_state, GFP_NOFS);
ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
&cached_state);
if (ret) {
unlock_extent_cached(io_tree, block_start, block_end,
&cached_state, GFP_NOFS);
goto out_unlock;
}
if (offset != blocksize) {
if (!len)
len = blocksize - offset;
kaddr = kmap(page);
if (front)
memset(kaddr + (block_start - page_offset(page)),
0, offset);
else
memset(kaddr + (block_start - page_offset(page)) + offset,
0, len);
flush_dcache_page(page);
kunmap(page);
}
ClearPageChecked(page);
set_page_dirty(page);
unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
GFP_NOFS);
out_unlock:
if (ret)
btrfs_delalloc_release_space(inode, block_start,
blocksize);
unlock_page(page);
put_page(page);
out:
return ret;
}
static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
u64 offset, u64 len)
{
struct btrfs_trans_handle *trans;
int ret;
/*
* Still need to make sure the inode looks like it's been updated so
* that any holes get logged if we fsync.
*/
if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
BTRFS_I(inode)->last_trans = root->fs_info->generation;
BTRFS_I(inode)->last_sub_trans = root->log_transid;
BTRFS_I(inode)->last_log_commit = root->last_log_commit;
return 0;
}
/*
* 1 - for the one we're dropping
* 1 - for the one we're adding
* 1 - for updating the inode.
*/
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
btrfs_end_transaction(trans, root);
return ret;
}
ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
0, 0, len, 0, len, 0, 0, 0);
if (ret)
btrfs_abort_transaction(trans, root, ret);
else
btrfs_update_inode(trans, root, inode);
btrfs_end_transaction(trans, root);
return ret;
}
/*
* This function puts in dummy file extents for the area we're creating a hole
* for. So if we are truncating this file to a larger size we need to insert
* these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
* the range between oldsize and size
*/
int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
u64 hole_start = ALIGN(oldsize, root->sectorsize);
u64 block_end = ALIGN(size, root->sectorsize);
u64 last_byte;
u64 cur_offset;
u64 hole_size;
int err = 0;
/*
* If our size started in the middle of a block we need to zero out the
* rest of the block before we expand the i_size, otherwise we could
* expose stale data.
*/
err = btrfs_truncate_block(inode, oldsize, 0, 0);
if (err)
return err;
if (size <= hole_start)
return 0;
while (1) {
struct btrfs_ordered_extent *ordered;
lock_extent_bits(io_tree, hole_start, block_end - 1,
&cached_state);
ordered = btrfs_lookup_ordered_range(inode, hole_start,
block_end - hole_start);
if (!ordered)
break;
unlock_extent_cached(io_tree, hole_start, block_end - 1,
&cached_state, GFP_NOFS);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
}
cur_offset = hole_start;
while (1) {
em = btrfs_get_extent(inode, NULL, 0, cur_offset,
block_end - cur_offset, 0);
if (IS_ERR(em)) {
err = PTR_ERR(em);
em = NULL;
break;
}
last_byte = min(extent_map_end(em), block_end);
last_byte = ALIGN(last_byte , root->sectorsize);
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
struct extent_map *hole_em;
hole_size = last_byte - cur_offset;
err = maybe_insert_hole(root, inode, cur_offset,
hole_size);
if (err)
break;
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + hole_size - 1, 0);
hole_em = alloc_extent_map();
if (!hole_em) {
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
goto next;
}
hole_em->start = cur_offset;
hole_em->len = hole_size;
hole_em->orig_start = cur_offset;
hole_em->block_start = EXTENT_MAP_HOLE;
hole_em->block_len = 0;
hole_em->orig_block_len = 0;
hole_em->ram_bytes = hole_size;
hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
hole_em->compress_type = BTRFS_COMPRESS_NONE;
hole_em->generation = root->fs_info->generation;
while (1) {
write_lock(&em_tree->lock);
err = add_extent_mapping(em_tree, hole_em, 1);
write_unlock(&em_tree->lock);
if (err != -EEXIST)
break;
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset +
hole_size - 1, 0);
}
free_extent_map(hole_em);
}
next:
free_extent_map(em);
em = NULL;
cur_offset = last_byte;
if (cur_offset >= block_end)
break;
}
free_extent_map(em);
unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
GFP_NOFS);
return err;
}
static int btrfs_setsize(struct inode *inode, struct iattr *attr)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
loff_t oldsize = i_size_read(inode);
loff_t newsize = attr->ia_size;
int mask = attr->ia_valid;
int ret;
/*
* The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
* special case where we need to update the times despite not having
* these flags set. For all other operations the VFS set these flags
* explicitly if it wants a timestamp update.
*/
if (newsize != oldsize) {
inode_inc_iversion(inode);
if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
inode->i_ctime = inode->i_mtime =
current_fs_time(inode->i_sb);
}
if (newsize > oldsize) {
/*
* Don't do an expanding truncate while snapshoting is ongoing.
* This is to ensure the snapshot captures a fully consistent
* state of this file - if the snapshot captures this expanding
* truncation, it must capture all writes that happened before
* this truncation.
*/
btrfs_wait_for_snapshot_creation(root);
ret = btrfs_cont_expand(inode, oldsize, newsize);
if (ret) {
btrfs_end_write_no_snapshoting(root);
return ret;
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_end_write_no_snapshoting(root);
return PTR_ERR(trans);
}
i_size_write(inode, newsize);
btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
pagecache_isize_extended(inode, oldsize, newsize);
ret = btrfs_update_inode(trans, root, inode);
btrfs_end_write_no_snapshoting(root);
btrfs_end_transaction(trans, root);
} else {
/*
* We're truncating a file that used to have good data down to
* zero. Make sure it gets into the ordered flush list so that
* any new writes get down to disk quickly.
*/
if (newsize == 0)
set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
&BTRFS_I(inode)->runtime_flags);
/*
* 1 for the orphan item we're going to add
* 1 for the orphan item deletion.
*/
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans))
return PTR_ERR(trans);
/*
* We need to do this in case we fail at _any_ point during the
* actual truncate. Once we do the truncate_setsize we could
* invalidate pages which forces any outstanding ordered io to
* be instantly completed which will give us extents that need
* to be truncated. If we fail to get an orphan inode down we
* could have left over extents that were never meant to live,
* so we need to garuntee from this point on that everything
* will be consistent.
*/
ret = btrfs_orphan_add(trans, inode);
btrfs_end_transaction(trans, root);
if (ret)
return ret;
/* we don't support swapfiles, so vmtruncate shouldn't fail */
truncate_setsize(inode, newsize);
/* Disable nonlocked read DIO to avoid the end less truncate */
btrfs_inode_block_unlocked_dio(inode);
inode_dio_wait(inode);
btrfs_inode_resume_unlocked_dio(inode);
ret = btrfs_truncate(inode);
if (ret && inode->i_nlink) {
int err;
/*
* failed to truncate, disk_i_size is only adjusted down
* as we remove extents, so it should represent the true
* size of the inode, so reset the in memory size and
* delete our orphan entry.
*/
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_orphan_del(NULL, inode);
return ret;
}
i_size_write(inode, BTRFS_I(inode)->disk_i_size);
err = btrfs_orphan_del(trans, inode);
if (err)
btrfs_abort_transaction(trans, root, err);
btrfs_end_transaction(trans, root);
}
}
return ret;
}
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
struct btrfs_root *root = BTRFS_I(inode)->root;
int err;
if (btrfs_root_readonly(root))
return -EROFS;
err = inode_change_ok(inode, attr);
if (err)
return err;
if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
err = btrfs_setsize(inode, attr);
if (err)
return err;
}
if (attr->ia_valid) {
setattr_copy(inode, attr);
inode_inc_iversion(inode);
err = btrfs_dirty_inode(inode);
if (!err && attr->ia_valid & ATTR_MODE)
err = posix_acl_chmod(inode, inode->i_mode);
}
return err;
}
/*
* While truncating the inode pages during eviction, we get the VFS calling
* btrfs_invalidatepage() against each page of the inode. This is slow because
* the calls to btrfs_invalidatepage() result in a huge amount of calls to
* lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
* extent_state structures over and over, wasting lots of time.
*
* Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
* those expensive operations on a per page basis and do only the ordered io
* finishing, while we release here the extent_map and extent_state structures,
* without the excessive merging and splitting.
*/
static void evict_inode_truncate_pages(struct inode *inode)
{
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
struct rb_node *node;
ASSERT(inode->i_state & I_FREEING);
truncate_inode_pages_final(&inode->i_data);
write_lock(&map_tree->lock);
while (!RB_EMPTY_ROOT(&map_tree->map)) {
struct extent_map *em;
node = rb_first(&map_tree->map);
em = rb_entry(node, struct extent_map, rb_node);
clear_bit(EXTENT_FLAG_PINNED, &em->flags);
clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
remove_extent_mapping(map_tree, em);
free_extent_map(em);
if (need_resched()) {
write_unlock(&map_tree->lock);
cond_resched();
write_lock(&map_tree->lock);
}
}
write_unlock(&map_tree->lock);
/*
* Keep looping until we have no more ranges in the io tree.
* We can have ongoing bios started by readpages (called from readahead)
* that have their endio callback (extent_io.c:end_bio_extent_readpage)
* still in progress (unlocked the pages in the bio but did not yet
* unlocked the ranges in the io tree). Therefore this means some
* ranges can still be locked and eviction started because before
* submitting those bios, which are executed by a separate task (work
* queue kthread), inode references (inode->i_count) were not taken
* (which would be dropped in the end io callback of each bio).
* Therefore here we effectively end up waiting for those bios and
* anyone else holding locked ranges without having bumped the inode's
* reference count - if we don't do it, when they access the inode's
* io_tree to unlock a range it may be too late, leading to an
* use-after-free issue.
*/
spin_lock(&io_tree->lock);
while (!RB_EMPTY_ROOT(&io_tree->state)) {
struct extent_state *state;
struct extent_state *cached_state = NULL;
u64 start;
u64 end;
node = rb_first(&io_tree->state);
state = rb_entry(node, struct extent_state, rb_node);
start = state->start;
end = state->end;
spin_unlock(&io_tree->lock);
lock_extent_bits(io_tree, start, end, &cached_state);
/*
* If still has DELALLOC flag, the extent didn't reach disk,
* and its reserved space won't be freed by delayed_ref.
* So we need to free its reserved space here.
* (Refer to comment in btrfs_invalidatepage, case 2)
*
* Note, end is the bytenr of last byte, so we need + 1 here.
*/
if (state->state & EXTENT_DELALLOC)
btrfs_qgroup_free_data(inode, start, end - start + 1);
clear_extent_bit(io_tree, start, end,
EXTENT_LOCKED | EXTENT_DIRTY |
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 1, 1,
&cached_state, GFP_NOFS);
cond_resched();
spin_lock(&io_tree->lock);
}
spin_unlock(&io_tree->lock);
}
void btrfs_evict_inode(struct inode *inode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv, *global_rsv;
int steal_from_global = 0;
u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
int ret;
trace_btrfs_inode_evict(inode);
evict_inode_truncate_pages(inode);
if (inode->i_nlink &&
((btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
btrfs_is_free_space_inode(inode)))
goto no_delete;
if (is_bad_inode(inode)) {
btrfs_orphan_del(NULL, inode);
goto no_delete;
}
/* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
if (!special_file(inode->i_mode))
btrfs_wait_ordered_range(inode, 0, (u64)-1);
btrfs_free_io_failure_record(inode, 0, (u64)-1);
if (root->fs_info->log_root_recovering) {
BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags));
goto no_delete;
}
if (inode->i_nlink > 0) {
BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
goto no_delete;
}
ret = btrfs_commit_inode_delayed_inode(inode);
if (ret) {
btrfs_orphan_del(NULL, inode);
goto no_delete;
}
rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
if (!rsv) {
btrfs_orphan_del(NULL, inode);
goto no_delete;
}
rsv->size = min_size;
rsv->failfast = 1;
global_rsv = &root->fs_info->global_block_rsv;
btrfs_i_size_write(inode, 0);
/*
* This is a bit simpler than btrfs_truncate since we've already
* reserved our space for our orphan item in the unlink, so we just
* need to reserve some slack space in case we add bytes and update
* inode item when doing the truncate.
*/
while (1) {
ret = btrfs_block_rsv_refill(root, rsv, min_size,
BTRFS_RESERVE_FLUSH_LIMIT);
/*
* Try and steal from the global reserve since we will
* likely not use this space anyway, we want to try as
* hard as possible to get this to work.
*/
if (ret)
steal_from_global++;
else
steal_from_global = 0;
ret = 0;
/*
* steal_from_global == 0: we reserved stuff, hooray!
* steal_from_global == 1: we didn't reserve stuff, boo!
* steal_from_global == 2: we've committed, still not a lot of
* room but maybe we'll have room in the global reserve this
* time.
* steal_from_global == 3: abandon all hope!
*/
if (steal_from_global > 2) {
btrfs_warn(root->fs_info,
"Could not get space for a delete, will truncate on mount %d",
ret);
btrfs_orphan_del(NULL, inode);
btrfs_free_block_rsv(root, rsv);
goto no_delete;
}
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_orphan_del(NULL, inode);
btrfs_free_block_rsv(root, rsv);
goto no_delete;
}
/*
* We can't just steal from the global reserve, we need tomake
* sure there is room to do it, if not we need to commit and try
* again.
*/
if (steal_from_global) {
if (!btrfs_check_space_for_delayed_refs(trans, root))
ret = btrfs_block_rsv_migrate(global_rsv, rsv,
min_size);
else
ret = -ENOSPC;
}
/*
* Couldn't steal from the global reserve, we have too much
* pending stuff built up, commit the transaction and try it
* again.
*/
if (ret) {
ret = btrfs_commit_transaction(trans, root);
if (ret) {
btrfs_orphan_del(NULL, inode);
btrfs_free_block_rsv(root, rsv);
goto no_delete;
}
continue;
} else {
steal_from_global = 0;
}
trans->block_rsv = rsv;
ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
if (ret != -ENOSPC && ret != -EAGAIN)
break;
trans->block_rsv = &root->fs_info->trans_block_rsv;
btrfs_end_transaction(trans, root);
trans = NULL;
btrfs_btree_balance_dirty(root);
}
btrfs_free_block_rsv(root, rsv);
/*
* Errors here aren't a big deal, it just means we leave orphan items
* in the tree. They will be cleaned up on the next mount.
*/
if (ret == 0) {
trans->block_rsv = root->orphan_block_rsv;
btrfs_orphan_del(trans, inode);
} else {
btrfs_orphan_del(NULL, inode);
}
trans->block_rsv = &root->fs_info->trans_block_rsv;
if (!(root == root->fs_info->tree_root ||
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
btrfs_return_ino(root, btrfs_ino(inode));
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
no_delete:
btrfs_remove_delayed_node(inode);
clear_inode(inode);
}
/*
* this returns the key found in the dir entry in the location pointer.
* If no dir entries were found, location->objectid is 0.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
struct btrfs_key *location)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
namelen, 0);
if (IS_ERR(di))
ret = PTR_ERR(di);
if (IS_ERR_OR_NULL(di))
goto out_err;
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
out:
btrfs_free_path(path);
return ret;
out_err:
location->objectid = 0;
goto out;
}
/*
* when we hit a tree root in a directory, the btrfs part of the inode
* needs to be changed to reflect the root directory of the tree root. This
* is kind of like crossing a mount point.
*/
static int fixup_tree_root_location(struct btrfs_root *root,
struct inode *dir,
struct dentry *dentry,
struct btrfs_key *location,
struct btrfs_root **sub_root)
{
struct btrfs_path *path;
struct btrfs_root *new_root;
struct btrfs_root_ref *ref;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret;
int err = 0;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
err = -ENOENT;
key.objectid = BTRFS_I(dir)->root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = location->objectid;
ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
0, 0);
if (ret) {
if (ret < 0)
err = ret;
goto out;
}
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
goto out;
ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
(unsigned long)(ref + 1),
dentry->d_name.len);
if (ret)
goto out;
btrfs_release_path(path);
new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
if (IS_ERR(new_root)) {
err = PTR_ERR(new_root);
goto out;
}
*sub_root = new_root;
location->objectid = btrfs_root_dirid(&new_root->root_item);
location->type = BTRFS_INODE_ITEM_KEY;
location->offset = 0;
err = 0;
out:
btrfs_free_path(path);
return err;
}
static void inode_tree_add(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_inode *entry;
struct rb_node **p;
struct rb_node *parent;
struct rb_node *new = &BTRFS_I(inode)->rb_node;
u64 ino = btrfs_ino(inode);
if (inode_unhashed(inode))
return;
parent = NULL;
spin_lock(&root->inode_lock);
p = &root->inode_tree.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_inode, rb_node);
if (ino < btrfs_ino(&entry->vfs_inode))
p = &parent->rb_left;
else if (ino > btrfs_ino(&entry->vfs_inode))
p = &parent->rb_right;
else {
WARN_ON(!(entry->vfs_inode.i_state &
(I_WILL_FREE | I_FREEING)));
rb_replace_node(parent, new, &root->inode_tree);
RB_CLEAR_NODE(parent);
spin_unlock(&root->inode_lock);
return;
}
}
rb_link_node(new, parent, p);
rb_insert_color(new, &root->inode_tree);
spin_unlock(&root->inode_lock);
}
static void inode_tree_del(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int empty = 0;
spin_lock(&root->inode_lock);
if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
empty = RB_EMPTY_ROOT(&root->inode_tree);
}
spin_unlock(&root->inode_lock);
if (empty && btrfs_root_refs(&root->root_item) == 0) {
synchronize_srcu(&root->fs_info->subvol_srcu);
spin_lock(&root->inode_lock);
empty = RB_EMPTY_ROOT(&root->inode_tree);
spin_unlock(&root->inode_lock);
if (empty)
btrfs_add_dead_root(root);
}
}
void btrfs_invalidate_inodes(struct btrfs_root *root)
{
struct rb_node *node;
struct rb_node *prev;
struct btrfs_inode *entry;
struct inode *inode;
u64 objectid = 0;
if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
WARN_ON(btrfs_root_refs(&root->root_item) != 0);
spin_lock(&root->inode_lock);
again:
node = root->inode_tree.rb_node;
prev = NULL;
while (node) {
prev = node;
entry = rb_entry(node, struct btrfs_inode, rb_node);
if (objectid < btrfs_ino(&entry->vfs_inode))
node = node->rb_left;
else if (objectid > btrfs_ino(&entry->vfs_inode))
node = node->rb_right;
else
break;
}
if (!node) {
while (prev) {
entry = rb_entry(prev, struct btrfs_inode, rb_node);
if (objectid <= btrfs_ino(&entry->vfs_inode)) {
node = prev;
break;
}
prev = rb_next(prev);
}
}
while (node) {
entry = rb_entry(node, struct btrfs_inode, rb_node);
objectid = btrfs_ino(&entry->vfs_inode) + 1;
inode = igrab(&entry->vfs_inode);
if (inode) {
spin_unlock(&root->inode_lock);
if (atomic_read(&inode->i_count) > 1)
d_prune_aliases(inode);
/*
* btrfs_drop_inode will have it removed from
* the inode cache when its usage count
* hits zero.
*/
iput(inode);
cond_resched();
spin_lock(&root->inode_lock);
goto again;
}
if (cond_resched_lock(&root->inode_lock))
goto again;
node = rb_next(node);
}
spin_unlock(&root->inode_lock);
}
static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
struct btrfs_iget_args *args = p;
inode->i_ino = args->location->objectid;
memcpy(&BTRFS_I(inode)->location, args->location,
sizeof(*args->location));
BTRFS_I(inode)->root = args->root;
return 0;
}
static int btrfs_find_actor(struct inode *inode, void *opaque)
{
struct btrfs_iget_args *args = opaque;
return args->location->objectid == BTRFS_I(inode)->location.objectid &&
args->root == BTRFS_I(inode)->root;
}
static struct inode *btrfs_iget_locked(struct super_block *s,
struct btrfs_key *location,
struct btrfs_root *root)
{
struct inode *inode;
struct btrfs_iget_args args;
unsigned long hashval = btrfs_inode_hash(location->objectid, root);
args.location = location;
args.root = root;
inode = iget5_locked(s, hashval, btrfs_find_actor,
btrfs_init_locked_inode,
(void *)&args);
return inode;
}
/* Get an inode object given its location and corresponding root.
* Returns in *is_new if the inode was read from disk
*/
struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
struct btrfs_root *root, int *new)
{
struct inode *inode;
inode = btrfs_iget_locked(s, location, root);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
btrfs_read_locked_inode(inode);
if (!is_bad_inode(inode)) {
inode_tree_add(inode);
unlock_new_inode(inode);
if (new)
*new = 1;
} else {
unlock_new_inode(inode);
iput(inode);
inode = ERR_PTR(-ESTALE);
}
}
return inode;
}
static struct inode *new_simple_dir(struct super_block *s,
struct btrfs_key *key,
struct btrfs_root *root)
{
struct inode *inode = new_inode(s);
if (!inode)
return ERR_PTR(-ENOMEM);
BTRFS_I(inode)->root = root;
memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
inode->i_op = &btrfs_dir_ro_inode_operations;
inode->i_fop = &simple_dir_operations;
inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
inode->i_mtime = current_fs_time(inode->i_sb);
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
return inode;
}
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
{
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
int index;
int ret = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ret = btrfs_inode_by_name(dir, dentry, &location);
if (ret < 0)
return ERR_PTR(ret);
if (location.objectid == 0)
return ERR_PTR(-ENOENT);
if (location.type == BTRFS_INODE_ITEM_KEY) {
inode = btrfs_iget(dir->i_sb, &location, root, NULL);
return inode;
}
BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
index = srcu_read_lock(&root->fs_info->subvol_srcu);
ret = fixup_tree_root_location(root, dir, dentry,
&location, &sub_root);
if (ret < 0) {
if (ret != -ENOENT)
inode = ERR_PTR(ret);
else
inode = new_simple_dir(dir->i_sb, &location, sub_root);
} else {
inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
}
srcu_read_unlock(&root->fs_info->subvol_srcu, index);
if (!IS_ERR(inode) && root != sub_root) {
down_read(&root->fs_info->cleanup_work_sem);
if (!(inode->i_sb->s_flags & MS_RDONLY))
ret = btrfs_orphan_cleanup(sub_root);
up_read(&root->fs_info->cleanup_work_sem);
if (ret) {
iput(inode);
inode = ERR_PTR(ret);
}
}
return inode;
}
static int btrfs_dentry_delete(const struct dentry *dentry)
{
struct btrfs_root *root;
struct inode *inode = d_inode(dentry);
if (!inode && !IS_ROOT(dentry))
inode = d_inode(dentry->d_parent);
if (inode) {
root = BTRFS_I(inode)->root;
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return 1;
}
return 0;
}
static void btrfs_dentry_release(struct dentry *dentry)
{
kfree(dentry->d_fsdata);
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode;
inode = btrfs_lookup_dentry(dir, dentry);
if (IS_ERR(inode)) {
if (PTR_ERR(inode) == -ENOENT)
inode = NULL;
else
return ERR_CAST(inode);
}
return d_splice_alias(inode, dentry);
}
unsigned char btrfs_filetype_table[] = {
DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};
static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_item *item;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
struct list_head ins_list;
struct list_head del_list;
int ret;
struct extent_buffer *leaf;
int slot;
unsigned char d_type;
int over = 0;
u32 di_cur;
u32 di_total;
u32 di_len;
int key_type = BTRFS_DIR_INDEX_KEY;
char tmp_name[32];
char *name_ptr;
int name_len;
int is_curr = 0; /* ctx->pos points to the current index? */
bool emitted;
/* FIXME, use a real flag for deciding about the key type */
if (root->fs_info->tree_root == root)
key_type = BTRFS_DIR_ITEM_KEY;
if (!dir_emit_dots(file, ctx))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_FORWARD;
if (key_type == BTRFS_DIR_INDEX_KEY) {
INIT_LIST_HEAD(&ins_list);
INIT_LIST_HEAD(&del_list);
btrfs_get_delayed_items(inode, &ins_list, &del_list);
}
key.type = key_type;
key.offset = ctx->pos;
key.objectid = btrfs_ino(inode);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
emitted = false;
while (1) {
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto err;
else if (ret > 0)
break;
continue;
}
item = btrfs_item_nr(slot);
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid)
break;
if (found_key.type != key_type)
break;
if (found_key.offset < ctx->pos)
goto next;
if (key_type == BTRFS_DIR_INDEX_KEY &&
btrfs_should_delete_dir_index(&del_list,
found_key.offset))
goto next;
ctx->pos = found_key.offset;
is_curr = 1;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
di_cur = 0;
di_total = btrfs_item_size(leaf, item);
while (di_cur < di_total) {
struct btrfs_key location;
if (verify_dir_item(root, leaf, di))
break;
name_len = btrfs_dir_name_len(leaf, di);
if (name_len <= sizeof(tmp_name)) {
name_ptr = tmp_name;
} else {
name_ptr = kmalloc(name_len, GFP_KERNEL);
if (!name_ptr) {
ret = -ENOMEM;
goto err;
}
}
read_extent_buffer(leaf, name_ptr,
(unsigned long)(di + 1), name_len);
d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
/* is this a reference to our own snapshot? If so
* skip it.
*
* In contrast to old kernels, we insert the snapshot's
* dir item and dir index after it has been created, so
* we won't find a reference to our own snapshot. We
* still keep the following code for backward
* compatibility.
*/
if (location.type == BTRFS_ROOT_ITEM_KEY &&
location.objectid == root->root_key.objectid) {
over = 0;
goto skip;
}
over = !dir_emit(ctx, name_ptr, name_len,
location.objectid, d_type);
skip:
if (name_ptr != tmp_name)
kfree(name_ptr);
if (over)
goto nopos;
emitted = true;
di_len = btrfs_dir_name_len(leaf, di) +
btrfs_dir_data_len(leaf, di) + sizeof(*di);
di_cur += di_len;
di = (struct btrfs_dir_item *)((char *)di + di_len);
}
next:
path->slots[0]++;
}
if (key_type == BTRFS_DIR_INDEX_KEY) {
if (is_curr)
ctx->pos++;
ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
if (ret)
goto nopos;
}
/*
* If we haven't emitted any dir entry, we must not touch ctx->pos as
* it was was set to the termination value in previous call. We assume
* that "." and ".." were emitted if we reach this point and set the
* termination value as well for an empty directory.
*/
if (ctx->pos > 2 && !emitted)
goto nopos;
/* Reached end of directory/root. Bump pos past the last item. */
ctx->pos++;
/*
* Stop new entries from being returned after we return the last
* entry.
*
* New directory entries are assigned a strictly increasing
* offset. This means that new entries created during readdir
* are *guaranteed* to be seen in the future by that readdir.
* This has broken buggy programs which operate on names as
* they're returned by readdir. Until we re-use freed offsets
* we have this hack to stop new entries from being returned
* under the assumption that they'll never reach this huge
* offset.
*
* This is being careful not to overflow 32bit loff_t unless the
* last entry requires it because doing so has broken 32bit apps
* in the past.
*/
if (key_type == BTRFS_DIR_INDEX_KEY) {
if (ctx->pos >= INT_MAX)
ctx->pos = LLONG_MAX;
else
ctx->pos = INT_MAX;
}
nopos:
ret = 0;
err:
if (key_type == BTRFS_DIR_INDEX_KEY)
btrfs_put_delayed_items(&ins_list, &del_list);
btrfs_free_path(path);
return ret;
}
int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret = 0;
bool nolock = false;
if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
return 0;
if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
nolock = true;
if (wbc->sync_mode == WB_SYNC_ALL) {
if (nolock)
trans = btrfs_join_transaction_nolock(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_commit_transaction(trans, root);
}
return ret;
}
/*
* This is somewhat expensive, updating the tree every time the
* inode changes. But, it is most likely to find the inode in cache.
* FIXME, needs more benchmarking...there are no reasons other than performance
* to keep or drop this code.
*/
static int btrfs_dirty_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret;
if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
return 0;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, inode);
if (ret && ret == -ENOSPC) {
/* whoops, lets try again with the full transaction */
btrfs_end_transaction(trans, root);
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans, root);
if (BTRFS_I(inode)->delayed_node)
btrfs_balance_delayed_items(root);
return ret;
}
/*
* This is a copy of file_update_time. We need this so we can return error on
* ENOSPC for updating the inode in the case of file write and mmap writes.
*/
static int btrfs_update_time(struct inode *inode, struct timespec *now,
int flags)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
if (btrfs_root_readonly(root))
return -EROFS;
if (flags & S_VERSION)
inode_inc_iversion(inode);
if (flags & S_CTIME)
inode->i_ctime = *now;
if (flags & S_MTIME)
inode->i_mtime = *now;
if (flags & S_ATIME)
inode->i_atime = *now;
return btrfs_dirty_inode(inode);
}
/*
* find the highest existing sequence number in a directory
* and then set the in-memory index_cnt variable to reflect
* free sequence numbers
*/
static int btrfs_set_inode_index_count(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key key, found_key;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = (u64)-1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/* FIXME: we should be able to handle this */
if (ret == 0)
goto out;
ret = 0;
/*
* MAGIC NUMBER EXPLANATION:
* since we search a directory based on f_pos we have to start at 2
* since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
* else has to start at 2
*/
if (path->slots[0] == 0) {
BTRFS_I(inode)->index_cnt = 2;
goto out;
}
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != btrfs_ino(inode) ||
found_key.type != BTRFS_DIR_INDEX_KEY) {
BTRFS_I(inode)->index_cnt = 2;
goto out;
}
BTRFS_I(inode)->index_cnt = found_key.offset + 1;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper to find a free sequence number in a given directory. This current
* code is very simple, later versions will do smarter things in the btree
*/
int btrfs_set_inode_index(struct inode *dir, u64 *index)
{
int ret = 0;
if (BTRFS_I(dir)->index_cnt == (u64)-1) {
ret = btrfs_inode_delayed_dir_index_count(dir);
if (ret) {
ret = btrfs_set_inode_index_count(dir);
if (ret)
return ret;
}
}
*index = BTRFS_I(dir)->index_cnt;
BTRFS_I(dir)->index_cnt++;
return ret;
}
static int btrfs_insert_inode_locked(struct inode *inode)
{
struct btrfs_iget_args args;
args.location = &BTRFS_I(inode)->location;
args.root = BTRFS_I(inode)->root;
return insert_inode_locked4(inode,
btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
btrfs_find_actor, &args);
}
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir,
const char *name, int name_len,
u64 ref_objectid, u64 objectid,
umode_t mode, u64 *index)
{
struct inode *inode;
struct btrfs_inode_item *inode_item;
struct btrfs_key *location;
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
struct btrfs_key key[2];
u32 sizes[2];
int nitems = name ? 2 : 1;
unsigned long ptr;
int ret;
path = btrfs_alloc_path();
if (!path)
return ERR_PTR(-ENOMEM);
inode = new_inode(root->fs_info->sb);
if (!inode) {
btrfs_free_path(path);
return ERR_PTR(-ENOMEM);
}
/*
* O_TMPFILE, set link count to 0, so that after this point,
* we fill in an inode item with the correct link count.
*/
if (!name)
set_nlink(inode, 0);
/*
* we have to initialize this early, so we can reclaim the inode
* number if we fail afterwards in this function.
*/
inode->i_ino = objectid;
if (dir && name) {
trace_btrfs_inode_request(dir);
ret = btrfs_set_inode_index(dir, index);
if (ret) {
btrfs_free_path(path);
iput(inode);
return ERR_PTR(ret);
}
} else if (dir) {
*index = 0;
}
/*
* index_cnt is ignored for everything but a dir,
* btrfs_get_inode_index_count has an explanation for the magic
* number
*/
BTRFS_I(inode)->index_cnt = 2;
BTRFS_I(inode)->dir_index = *index;
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->generation = trans->transid;
inode->i_generation = BTRFS_I(inode)->generation;
/*
* We could have gotten an inode number from somebody who was fsynced
* and then removed in this same transaction, so let's just set full
* sync since it will be a full sync anyway and this will blow away the
* old info in the log.
*/
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
key[0].objectid = objectid;
key[0].type = BTRFS_INODE_ITEM_KEY;
key[0].offset = 0;
sizes[0] = sizeof(struct btrfs_inode_item);
if (name) {
/*
* Start new inodes with an inode_ref. This is slightly more
* efficient for small numbers of hard links since they will
* be packed into one item. Extended refs will kick in if we
* add more hard links than can fit in the ref item.
*/
key[1].objectid = objectid;
key[1].type = BTRFS_INODE_REF_KEY;
key[1].offset = ref_objectid;
sizes[1] = name_len + sizeof(*ref);
}
location = &BTRFS_I(inode)->location;
location->objectid = objectid;
location->offset = 0;
location->type = BTRFS_INODE_ITEM_KEY;
ret = btrfs_insert_inode_locked(inode);
if (ret < 0)
goto fail;
path->leave_spinning = 1;
ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
if (ret != 0)
goto fail_unlock;
inode_init_owner(inode, dir, mode);
inode_set_bytes(inode, 0);
inode->i_mtime = current_fs_time(inode->i_sb);
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
sizeof(*inode_item));
fill_inode_item(trans, path->nodes[0], inode_item, inode);
if (name) {
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
struct btrfs_inode_ref);
btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
ptr = (unsigned long)(ref + 1);
write_extent_buffer(path->nodes[0], name, ptr, name_len);
}
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
btrfs_inherit_iflags(inode, dir);
if (S_ISREG(mode)) {
if (btrfs_test_opt(root, NODATASUM))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
if (btrfs_test_opt(root, NODATACOW))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
BTRFS_INODE_NODATASUM;
}
inode_tree_add(inode);
trace_btrfs_inode_new(inode);
btrfs_set_inode_last_trans(trans, inode);
btrfs_update_root_times(trans, root);
ret = btrfs_inode_inherit_props(trans, inode, dir);
if (ret)
btrfs_err(root->fs_info,
"error inheriting props for ino %llu (root %llu): %d",
btrfs_ino(inode), root->root_key.objectid, ret);
return inode;
fail_unlock:
unlock_new_inode(inode);
fail:
if (dir && name)
BTRFS_I(dir)->index_cnt--;
btrfs_free_path(path);
iput(inode);
return ERR_PTR(ret);
}
static inline u8 btrfs_inode_type(struct inode *inode)
{
return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
}
/*
* utility function to add 'inode' into 'parent_inode' with
* a give name and a given sequence number.
* if 'add_backref' is true, also insert a backref from the
* inode to the parent directory.
*/
int btrfs_add_link(struct btrfs_trans_handle *trans,
struct inode *parent_inode, struct inode *inode,
const char *name, int name_len, int add_backref, u64 index)
{
int ret = 0;
struct btrfs_key key;
struct btrfs_root *root = BTRFS_I(parent_inode)->root;
u64 ino = btrfs_ino(inode);
u64 parent_ino = btrfs_ino(parent_inode);
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
} else {
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
}
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
key.objectid, root->root_key.objectid,
parent_ino, index, name, name_len);
} else if (add_backref) {
ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
parent_ino, index);
}
/* Nothing to clean up yet */
if (ret)
return ret;
ret = btrfs_insert_dir_item(trans, root, name, name_len,
parent_inode, &key,
btrfs_inode_type(inode), index);
if (ret == -EEXIST || ret == -EOVERFLOW)
goto fail_dir_item;
else if (ret) {
btrfs_abort_transaction(trans, root, ret);
return ret;
}
btrfs_i_size_write(parent_inode, parent_inode->i_size +
name_len * 2);
inode_inc_iversion(parent_inode);
parent_inode->i_mtime = parent_inode->i_ctime =
current_fs_time(parent_inode->i_sb);
ret = btrfs_update_inode(trans, root, parent_inode);
if (ret)
btrfs_abort_transaction(trans, root, ret);
return ret;
fail_dir_item:
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
u64 local_index;
int err;
err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
key.objectid, root->root_key.objectid,
parent_ino, &local_index, name, name_len);
} else if (add_backref) {
u64 local_index;
int err;
err = btrfs_del_inode_ref(trans, root, name, name_len,
ino, parent_ino, &local_index);
}
return ret;
}
static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
struct inode *dir, struct dentry *dentry,
struct inode *inode, int backref, u64 index)
{
int err = btrfs_add_link(trans, dir, inode,
dentry->d_name.name, dentry->d_name.len,
backref, index);
if (err > 0)
err = -EEXIST;
return err;
}
static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int err;
int drop_inode = 0;
u64 objectid;
u64 index = 0;
/*
* 2 for inode item and ref
* 2 for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(dir), objectid,
mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock_inode;
err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
if (err) {
goto out_unlock_inode;
} else {
btrfs_update_inode(trans, root, inode);
unlock_new_inode(inode);
d_instantiate(dentry, inode);
}
out_unlock:
btrfs_end_transaction(trans, root);
btrfs_balance_delayed_items(root);
btrfs_btree_balance_dirty(root);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
return err;
out_unlock_inode:
drop_inode = 1;
unlock_new_inode(inode);
goto out_unlock;
}
static int btrfs_create(struct inode *dir, struct dentry *dentry,
umode_t mode, bool excl)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int drop_inode_on_err = 0;
int err;
u64 objectid;
u64 index = 0;
/*
* 2 for inode item and ref
* 2 for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(dir), objectid,
mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_unlock;
}
drop_inode_on_err = 1;
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock_inode;
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_unlock_inode;
err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
if (err)
goto out_unlock_inode;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
unlock_new_inode(inode);
d_instantiate(dentry, inode);
out_unlock:
btrfs_end_transaction(trans, root);
if (err && drop_inode_on_err) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_balance_delayed_items(root);
btrfs_btree_balance_dirty(root);
return err;
out_unlock_inode:
unlock_new_inode(inode);
goto out_unlock;
}
static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans = NULL;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = d_inode(old_dentry);
u64 index;
int err;
int drop_inode = 0;
/* do not allow sys_link's with other subvols of the same device */
if (root->objectid != BTRFS_I(inode)->root->objectid)
return -EXDEV;
if (inode->i_nlink >= BTRFS_LINK_MAX)
return -EMLINK;
err = btrfs_set_inode_index(dir, &index);
if (err)
goto fail;
/*
* 2 items for inode and inode ref
* 2 items for dir items
* 1 item for parent inode
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
trans = NULL;
goto fail;
}
/* There are several dir indexes for this inode, clear the cache. */
BTRFS_I(inode)->dir_index = 0ULL;
inc_nlink(inode);
inode_inc_iversion(inode);
inode->i_ctime = current_fs_time(inode->i_sb);
ihold(inode);
set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
if (err) {
drop_inode = 1;
} else {
struct dentry *parent = dentry->d_parent;
err = btrfs_update_inode(trans, root, inode);
if (err)
goto fail;
if (inode->i_nlink == 1) {
/*
* If new hard link count is 1, it's a file created
* with open(2) O_TMPFILE flag.
*/
err = btrfs_orphan_del(trans, inode);
if (err)
goto fail;
}
d_instantiate(dentry, inode);
btrfs_log_new_name(trans, inode, NULL, parent);
}
btrfs_balance_delayed_items(root);
fail:
if (trans)
btrfs_end_transaction(trans, root);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
}
static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct inode *inode = NULL;
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
int err = 0;
int drop_on_err = 0;
u64 objectid = 0;
u64 index = 0;
/*
* 2 items for inode and ref
* 2 items for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_fail;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(dir), objectid,
S_IFDIR | mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fail;
}
drop_on_err = 1;
/* these must be set before we unlock the inode */
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_fail_inode;
btrfs_i_size_write(inode, 0);
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_fail_inode;
err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
dentry->d_name.len, 0, index);
if (err)
goto out_fail_inode;
d_instantiate(dentry, inode);
/*
* mkdir is special. We're unlocking after we call d_instantiate
* to avoid a race with nfsd calling d_instantiate.
*/
unlock_new_inode(inode);
drop_on_err = 0;
out_fail:
btrfs_end_transaction(trans, root);
if (drop_on_err) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_balance_delayed_items(root);
btrfs_btree_balance_dirty(root);
return err;
out_fail_inode:
unlock_new_inode(inode);
goto out_fail;
}
/* Find next extent map of a given extent map, caller needs to ensure locks */
static struct extent_map *next_extent_map(struct extent_map *em)
{
struct rb_node *next;
next = rb_next(&em->rb_node);
if (!next)
return NULL;
return container_of(next, struct extent_map, rb_node);
}
static struct extent_map *prev_extent_map(struct extent_map *em)
{
struct rb_node *prev;
prev = rb_prev(&em->rb_node);
if (!prev)
return NULL;
return container_of(prev, struct extent_map, rb_node);
}
/* helper for btfs_get_extent. Given an existing extent in the tree,
* the existing extent is the nearest extent to map_start,
* and an extent that you want to insert, deal with overlap and insert
* the best fitted new extent into the tree.
*/
static int merge_extent_mapping(struct extent_map_tree *em_tree,
struct extent_map *existing,
struct extent_map *em,
u64 map_start)
{
struct extent_map *prev;
struct extent_map *next;
u64 start;
u64 end;
u64 start_diff;
BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
if (existing->start > map_start) {
next = existing;
prev = prev_extent_map(next);
} else {
prev = existing;
next = next_extent_map(prev);
}
start = prev ? extent_map_end(prev) : em->start;
start = max_t(u64, start, em->start);
end = next ? next->start : extent_map_end(em);
end = min_t(u64, end, extent_map_end(em));
start_diff = start - em->start;
em->start = start;
em->len = end - start;
if (em->block_start < EXTENT_MAP_LAST_BYTE &&
!test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
em->block_start += start_diff;
em->block_len -= start_diff;
}
return add_extent_mapping(em_tree, em, 0);
}
static noinline int uncompress_inline(struct btrfs_path *path,
struct page *page,
size_t pg_offset, u64 extent_offset,
struct btrfs_file_extent_item *item)
{
int ret;
struct extent_buffer *leaf = path->nodes[0];
char *tmp;
size_t max_size;
unsigned long inline_size;
unsigned long ptr;
int compress_type;
WARN_ON(pg_offset != 0);
compress_type = btrfs_file_extent_compression(leaf, item);
max_size = btrfs_file_extent_ram_bytes(leaf, item);
inline_size = btrfs_file_extent_inline_item_len(leaf,
btrfs_item_nr(path->slots[0]));
tmp = kmalloc(inline_size, GFP_NOFS);
if (!tmp)
return -ENOMEM;
ptr = btrfs_file_extent_inline_start(item);
read_extent_buffer(leaf, tmp, ptr, inline_size);
max_size = min_t(unsigned long, PAGE_SIZE, max_size);
ret = btrfs_decompress(compress_type, tmp, page,
extent_offset, inline_size, max_size);
kfree(tmp);
return ret;
}
/*
* a bit scary, this does extent mapping from logical file offset to the disk.
* the ugly parts come from merging extents from the disk with the in-ram
* representation. This gets more complex because of the data=ordered code,
* where the in-ram extents might be locked pending data=ordered completion.
*
* This also copies inline extents directly into the page.
*/
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
size_t pg_offset, u64 start, u64 len,
int create)
{
int ret;
int err = 0;
u64 extent_start = 0;
u64 extent_end = 0;
u64 objectid = btrfs_ino(inode);
u32 found_type;
struct btrfs_path *path = NULL;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *item;
struct extent_buffer *leaf;
struct btrfs_key found_key;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_trans_handle *trans = NULL;
const bool new_inline = !page || create;
again:
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
if (em)
em->bdev = root->fs_info->fs_devices->latest_bdev;
read_unlock(&em_tree->lock);
if (em) {
if (em->start > start || em->start + em->len <= start)
free_extent_map(em);
else if (em->block_start == EXTENT_MAP_INLINE && page)
free_extent_map(em);
else
goto out;
}
em = alloc_extent_map();
if (!em) {
err = -ENOMEM;
goto out;
}
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->start = EXTENT_MAP_HOLE;
em->orig_start = EXTENT_MAP_HOLE;
em->len = (u64)-1;
em->block_len = (u64)-1;
if (!path) {
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
/*
* Chances are we'll be called again, so go ahead and do
* readahead
*/
path->reada = READA_FORWARD;
}
ret = btrfs_lookup_file_extent(trans, root, path,
objectid, start, trans != NULL);
if (ret < 0) {
err = ret;
goto out;
}
if (ret != 0) {
if (path->slots[0] == 0)
goto not_found;
path->slots[0]--;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
/* are we inside the extent that was found? */
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = found_key.type;
if (found_key.objectid != objectid ||
found_type != BTRFS_EXTENT_DATA_KEY) {
/*
* If we backup past the first extent we want to move forward
* and see if there is an extent in front of us, otherwise we'll
* say there is a hole for our whole search range which can
* cause problems.
*/
extent_end = start;
goto next;
}
found_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
extent_end = extent_start +
btrfs_file_extent_num_bytes(leaf, item);
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
size_t size;
size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
extent_end = ALIGN(extent_start + size, root->sectorsize);
}
next:
if (start >= extent_end) {
path->slots[0]++;
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
err = ret;
goto out;
}
if (ret > 0)
goto not_found;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_EXTENT_DATA_KEY)
goto not_found;
if (start + len <= found_key.offset)
goto not_found;
if (start > found_key.offset)
goto next;
em->start = start;
em->orig_start = start;
em->len = found_key.offset - start;
goto not_found_em;
}
btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
goto insert;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
unsigned long ptr;
char *map;
size_t size;
size_t extent_offset;
size_t copy_size;
if (new_inline)
goto out;
size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
extent_offset = page_offset(page) + pg_offset - extent_start;
copy_size = min_t(u64, PAGE_SIZE - pg_offset,
size - extent_offset);
em->start = extent_start + extent_offset;
em->len = ALIGN(copy_size, root->sectorsize);
em->orig_block_len = em->len;
em->orig_start = em->start;
ptr = btrfs_file_extent_inline_start(item) + extent_offset;
if (create == 0 && !PageUptodate(page)) {
if (btrfs_file_extent_compression(leaf, item) !=
BTRFS_COMPRESS_NONE) {
ret = uncompress_inline(path, page, pg_offset,
extent_offset, item);
if (ret) {
err = ret;
goto out;
}
} else {
map = kmap(page);
read_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
if (pg_offset + copy_size < PAGE_SIZE) {
memset(map + pg_offset + copy_size, 0,
PAGE_SIZE - pg_offset -
copy_size);
}
kunmap(page);
}
flush_dcache_page(page);
} else if (create && PageUptodate(page)) {
BUG();
if (!trans) {
kunmap(page);
free_extent_map(em);
em = NULL;
btrfs_release_path(path);
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return ERR_CAST(trans);
goto again;
}
map = kmap(page);
write_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
kunmap(page);
btrfs_mark_buffer_dirty(leaf);
}
set_extent_uptodate(io_tree, em->start,
extent_map_end(em) - 1, NULL, GFP_NOFS);
goto insert;
}
not_found:
em->start = start;
em->orig_start = start;
em->len = len;
not_found_em:
em->block_start = EXTENT_MAP_HOLE;
set_bit(EXTENT_FLAG_VACANCY, &em->flags);
insert:
btrfs_release_path(path);
if (em->start > start || extent_map_end(em) <= start) {
btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
em->start, em->len, start, len);
err = -EIO;
goto out;
}
err = 0;
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 0);
/* it is possible that someone inserted the extent into the tree
* while we had the lock dropped. It is also possible that
* an overlapping map exists in the tree
*/
if (ret == -EEXIST) {
struct extent_map *existing;
ret = 0;
existing = search_extent_mapping(em_tree, start, len);
/*
* existing will always be non-NULL, since there must be
* extent causing the -EEXIST.
*/
if (start >= extent_map_end(existing) ||
start <= existing->start) {
/*
* The existing extent map is the one nearest to
* the [start, start + len) range which overlaps
*/
err = merge_extent_mapping(em_tree, existing,
em, start);
free_extent_map(existing);
if (err) {
free_extent_map(em);
em = NULL;
}
} else {
free_extent_map(em);
em = existing;
err = 0;
}
}
write_unlock(&em_tree->lock);
out:
trace_btrfs_get_extent(root, em);
btrfs_free_path(path);
if (trans) {
ret = btrfs_end_transaction(trans, root);
if (!err)
err = ret;
}
if (err) {
free_extent_map(em);
return ERR_PTR(err);
}
BUG_ON(!em); /* Error is always set */
return em;
}
struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
size_t pg_offset, u64 start, u64 len,
int create)
{
struct extent_map *em;
struct extent_map *hole_em = NULL;
u64 range_start = start;
u64 end;
u64 found;
u64 found_end;
int err = 0;
em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
if (IS_ERR(em))
return em;
if (em) {
/*
* if our em maps to
* - a hole or
* - a pre-alloc extent,
* there might actually be delalloc bytes behind it.
*/
if (em->block_start != EXTENT_MAP_HOLE &&
!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
return em;
else
hole_em = em;
}
/* check to see if we've wrapped (len == -1 or similar) */
end = start + len;
if (end < start)
end = (u64)-1;
else
end -= 1;
em = NULL;
/* ok, we didn't find anything, lets look for delalloc */
found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
end, len, EXTENT_DELALLOC, 1);
found_end = range_start + found;
if (found_end < range_start)
found_end = (u64)-1;
/*
* we didn't find anything useful, return
* the original results from get_extent()
*/
if (range_start > end || found_end <= start) {
em = hole_em;
hole_em = NULL;
goto out;
}
/* adjust the range_start to make sure it doesn't
* go backwards from the start they passed in
*/
range_start = max(start, range_start);
found = found_end - range_start;
if (found > 0) {
u64 hole_start = start;
u64 hole_len = len;
em = alloc_extent_map();
if (!em) {
err = -ENOMEM;
goto out;
}
/*
* when btrfs_get_extent can't find anything it
* returns one huge hole
*
* make sure what it found really fits our range, and
* adjust to make sure it is based on the start from
* the caller
*/
if (hole_em) {
u64 calc_end = extent_map_end(hole_em);
if (calc_end <= start || (hole_em->start > end)) {
free_extent_map(hole_em);
hole_em = NULL;
} else {
hole_start = max(hole_em->start, start);
hole_len = calc_end - hole_start;
}
}
em->bdev = NULL;
if (hole_em && range_start > hole_start) {
/* our hole starts before our delalloc, so we
* have to return just the parts of the hole
* that go until the delalloc starts
*/
em->len = min(hole_len,
range_start - hole_start);
em->start = hole_start;
em->orig_start = hole_start;
/*
* don't adjust block start at all,
* it is fixed at EXTENT_MAP_HOLE
*/
em->block_start = hole_em->block_start;
em->block_len = hole_len;
if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
} else {
em->start = range_start;
em->len = found;
em->orig_start = range_start;
em->block_start = EXTENT_MAP_DELALLOC;
em->block_len = found;
}
} else if (hole_em) {
return hole_em;
}
out:
free_extent_map(hole_em);
if (err) {
free_extent_map(em);
return ERR_PTR(err);
}
return em;
}
static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
u64 start, u64 len)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map *em;
struct btrfs_key ins;
u64 alloc_hint;
int ret;
alloc_hint = get_extent_allocation_hint(inode, start, len);
ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
alloc_hint, &ins, 1, 1);
if (ret)
return ERR_PTR(ret);
/*
* Create the ordered extent before the extent map. This is to avoid
* races with the fast fsync path that would lead to it logging file
* extent items that point to disk extents that were not yet written to.
* The fast fsync path collects ordered extents into a local list and
* then collects all the new extent maps, so we must create the ordered
* extent first and make sure the fast fsync path collects any new
* ordered extents after collecting new extent maps as well.
* The fsync path simply can not rely on inode_dio_wait() because it
* causes deadlock with AIO.
*/
ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
ins.offset, ins.offset, 0);
if (ret) {
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
return ERR_PTR(ret);
}
em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
ins.offset, ins.offset, ins.offset, 0);
if (IS_ERR(em)) {
struct btrfs_ordered_extent *oe;
btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
oe = btrfs_lookup_ordered_extent(inode, start);
ASSERT(oe);
if (WARN_ON(!oe))
return em;
set_bit(BTRFS_ORDERED_IOERR, &oe->flags);
set_bit(BTRFS_ORDERED_IO_DONE, &oe->flags);
btrfs_remove_ordered_extent(inode, oe);
/* Once for our lookup and once for the ordered extents tree. */
btrfs_put_ordered_extent(oe);
btrfs_put_ordered_extent(oe);
}
return em;
}
/*
* returns 1 when the nocow is safe, < 1 on error, 0 if the
* block must be cow'd
*/
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
u64 *ram_bytes)
{
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
int ret;
struct extent_buffer *leaf;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
u64 disk_bytenr;
u64 backref_offset;
u64 extent_end;
u64 num_bytes;
int slot;
int found_type;
bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
offset, 0);
if (ret < 0)
goto out;
slot = path->slots[0];
if (ret == 1) {
if (slot == 0) {
/* can't find the item, must cow */
ret = 0;
goto out;
}
slot--;
}
ret = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != btrfs_ino(inode) ||
key.type != BTRFS_EXTENT_DATA_KEY) {
/* not our file or wrong item type, must cow */
goto out;
}
if (key.offset > offset) {
/* Wrong offset, must cow */
goto out;
}
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(leaf, fi);
if (found_type != BTRFS_FILE_EXTENT_REG &&
found_type != BTRFS_FILE_EXTENT_PREALLOC) {
/* not a regular extent, must cow */
goto out;
}
if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
goto out;
extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
if (extent_end <= offset)
goto out;
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
if (disk_bytenr == 0)
goto out;
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out;
backref_offset = btrfs_file_extent_offset(leaf, fi);
if (orig_start) {
*orig_start = key.offset - backref_offset;
*orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
*ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
}
if (btrfs_extent_readonly(root, disk_bytenr))
goto out;
num_bytes = min(offset + *len, extent_end) - offset;
if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 range_end;
range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
ret = test_range_bit(io_tree, offset, range_end,
EXTENT_DELALLOC, 0, NULL);
if (ret) {
ret = -EAGAIN;
goto out;
}
}
btrfs_release_path(path);
/*
* look for other files referencing this extent, if we
* find any we must cow
*/
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = 0;
goto out;
}
ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
key.offset - backref_offset, disk_bytenr);
btrfs_end_transaction(trans, root);
if (ret) {
ret = 0;
goto out;
}
/*
* adjust disk_bytenr and num_bytes to cover just the bytes
* in this extent we are about to write. If there
* are any csums in that range we have to cow in order
* to keep the csums correct
*/
disk_bytenr += backref_offset;
disk_bytenr += offset - key.offset;
if (csum_exist_in_range(root, disk_bytenr, num_bytes))
goto out;
/*
* all of the above have passed, it is safe to overwrite this extent
* without cow
*/
*len = num_bytes;
ret = 1;
out:
btrfs_free_path(path);
return ret;
}
bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
{
struct radix_tree_root *root = &inode->i_mapping->page_tree;
int found = false;
void **pagep = NULL;
struct page *page = NULL;
int start_idx;
int end_idx;
start_idx = start >> PAGE_SHIFT;
/*
* end is the last byte in the last page. end == start is legal
*/
end_idx = end >> PAGE_SHIFT;
rcu_read_lock();
/* Most of the code in this while loop is lifted from
* find_get_page. It's been modified to begin searching from a
* page and return just the first page found in that range. If the
* found idx is less than or equal to the end idx then we know that
* a page exists. If no pages are found or if those pages are
* outside of the range then we're fine (yay!) */
while (page == NULL &&
radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
page = radix_tree_deref_slot(pagep);
if (unlikely(!page))
break;
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
page = NULL;
continue;
}
/*
* Otherwise, shmem/tmpfs must be storing a swap entry
* here as an exceptional entry: so return it without
* attempting to raise page count.
*/
page = NULL;
break; /* TODO: Is this relevant for this use case? */
}
if (!page_cache_get_speculative(page)) {
page = NULL;
continue;
}
/*
* Has the page moved?
* This is part of the lockless pagecache protocol. See
* include/linux/pagemap.h for details.
*/
if (unlikely(page != *pagep)) {
put_page(page);
page = NULL;
}
}
if (page) {
if (page->index <= end_idx)
found = true;
put_page(page);
}
rcu_read_unlock();
return found;
}
static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
struct extent_state **cached_state, int writing)
{
struct btrfs_ordered_extent *ordered;
int ret = 0;
while (1) {
lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
cached_state);
/*
* We're concerned with the entire range that we're going to be
* doing DIO to, so we need to make sure theres no ordered
* extents in this range.
*/
ordered = btrfs_lookup_ordered_range(inode, lockstart,
lockend - lockstart + 1);
/*
* We need to make sure there are no buffered pages in this
* range either, we could have raced between the invalidate in
* generic_file_direct_write and locking the extent. The
* invalidate needs to happen so that reads after a write do not
* get stale data.
*/
if (!ordered &&
(!writing ||
!btrfs_page_exists_in_range(inode, lockstart, lockend)))
break;
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
cached_state, GFP_NOFS);
if (ordered) {
/*
* If we are doing a DIO read and the ordered extent we
* found is for a buffered write, we can not wait for it
* to complete and retry, because if we do so we can
* deadlock with concurrent buffered writes on page
* locks. This happens only if our DIO read covers more
* than one extent map, if at this point has already
* created an ordered extent for a previous extent map
* and locked its range in the inode's io tree, and a
* concurrent write against that previous extent map's
* range and this range started (we unlock the ranges
* in the io tree only when the bios complete and
* buffered writes always lock pages before attempting
* to lock range in the io tree).
*/
if (writing ||
test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
btrfs_start_ordered_extent(inode, ordered, 1);
else
ret = -ENOTBLK;
btrfs_put_ordered_extent(ordered);
} else {
/*
* We could trigger writeback for this range (and wait
* for it to complete) and then invalidate the pages for
* this range (through invalidate_inode_pages2_range()),
* but that can lead us to a deadlock with a concurrent
* call to readpages() (a buffered read or a defrag call
* triggered a readahead) on a page lock due to an
* ordered dio extent we created before but did not have
* yet a corresponding bio submitted (whence it can not
* complete), which makes readpages() wait for that
* ordered extent to complete while holding a lock on
* that page.
*/
ret = -ENOTBLK;
}
if (ret)
break;
cond_resched();
}
return ret;
}
static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
u64 len, u64 orig_start,
u64 block_start, u64 block_len,
u64 orig_block_len, u64 ram_bytes,
int type)
{
struct extent_map_tree *em_tree;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
em_tree = &BTRFS_I(inode)->extent_tree;
em = alloc_extent_map();
if (!em)
return ERR_PTR(-ENOMEM);
em->start = start;
em->orig_start = orig_start;
em->mod_start = start;
em->mod_len = len;
em->len = len;
em->block_len = block_len;
em->block_start = block_start;
em->bdev = root->fs_info->fs_devices->latest_bdev;
em->orig_block_len = orig_block_len;
em->ram_bytes = ram_bytes;
em->generation = -1;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
if (type == BTRFS_ORDERED_PREALLOC)
set_bit(EXTENT_FLAG_FILLING, &em->flags);
do {
btrfs_drop_extent_cache(inode, em->start,
em->start + em->len - 1, 0);
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
} while (ret == -EEXIST);
if (ret) {
free_extent_map(em);
return ERR_PTR(ret);
}
return em;
}
static void adjust_dio_outstanding_extents(struct inode *inode,
struct btrfs_dio_data *dio_data,
const u64 len)
{
unsigned num_extents;
num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
/*
* If we have an outstanding_extents count still set then we're
* within our reservation, otherwise we need to adjust our inode
* counter appropriately.
*/
if (dio_data->outstanding_extents) {
dio_data->outstanding_extents -= num_extents;
} else {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents += num_extents;
spin_unlock(&BTRFS_I(inode)->lock);
}
}
static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_state *cached_state = NULL;
struct btrfs_dio_data *dio_data = NULL;
u64 start = iblock << inode->i_blkbits;
u64 lockstart, lockend;
u64 len = bh_result->b_size;
int unlock_bits = EXTENT_LOCKED;
int ret = 0;
if (create)
unlock_bits |= EXTENT_DIRTY;
else
len = min_t(u64, len, root->sectorsize);
lockstart = start;
lockend = start + len - 1;
if (current->journal_info) {
/*
* Need to pull our outstanding extents and set journal_info to NULL so
* that anything that needs to check if there's a transction doesn't get
* confused.
*/
dio_data = current->journal_info;
current->journal_info = NULL;
}
/*
* If this errors out it's because we couldn't invalidate pagecache for
* this range and we need to fallback to buffered.
*/
if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
create)) {
ret = -ENOTBLK;
goto err;
}
em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
/*
* Ok for INLINE and COMPRESSED extents we need to fallback on buffered
* io. INLINE is special, and we could probably kludge it in here, but
* it's still buffered so for safety lets just fall back to the generic
* buffered path.
*
* For COMPRESSED we _have_ to read the entire extent in so we can
* decompress it, so there will be buffering required no matter what we
* do, so go ahead and fallback to buffered.
*
* We return -ENOTBLK because thats what makes DIO go ahead and go back
* to buffered IO. Don't blame me, this is the price we pay for using
* the generic code.
*/
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
em->block_start == EXTENT_MAP_INLINE) {
free_extent_map(em);
ret = -ENOTBLK;
goto unlock_err;
}
/* Just a good old fashioned hole, return */
if (!create && (em->block_start == EXTENT_MAP_HOLE ||
test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
free_extent_map(em);
goto unlock_err;
}
/*
* We don't allocate a new extent in the following cases
*
* 1) The inode is marked as NODATACOW. In this case we'll just use the
* existing extent.
* 2) The extent is marked as PREALLOC. We're good to go here and can
* just use the extent.
*
*/
if (!create) {
len = min(len, em->len - (start - em->start));
lockstart = start + len;
goto unlock;
}
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
em->block_start != EXTENT_MAP_HOLE)) {
int type;
u64 block_start, orig_start, orig_block_len, ram_bytes;
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
type = BTRFS_ORDERED_PREALLOC;
else
type = BTRFS_ORDERED_NOCOW;
len = min(len, em->len - (start - em->start));
block_start = em->block_start + (start - em->start);
if (can_nocow_extent(inode, start, &len, &orig_start,
&orig_block_len, &ram_bytes) == 1) {
if (type == BTRFS_ORDERED_PREALLOC) {
free_extent_map(em);
em = create_pinned_em(inode, start, len,
orig_start,
block_start, len,
orig_block_len,
ram_bytes, type);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
}
ret = btrfs_add_ordered_extent_dio(inode, start,
block_start, len, len, type);
if (ret) {
free_extent_map(em);
goto unlock_err;
}
goto unlock;
}
}
/*
* this will cow the extent, reset the len in case we changed
* it above
*/
len = bh_result->b_size;
free_extent_map(em);
em = btrfs_new_extent_direct(inode, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
len = min(len, em->len - (start - em->start));
unlock:
bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
inode->i_blkbits;
bh_result->b_size = len;
bh_result->b_bdev = em->bdev;
set_buffer_mapped(bh_result);
if (create) {
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
set_buffer_new(bh_result);
/*
* Need to update the i_size under the extent lock so buffered
* readers will get the updated i_size when we unlock.
*/
if (start + len > i_size_read(inode))
i_size_write(inode, start + len);
adjust_dio_outstanding_extents(inode, dio_data, len);
btrfs_free_reserved_data_space(inode, start, len);
WARN_ON(dio_data->reserve < len);
dio_data->reserve -= len;
dio_data->unsubmitted_oe_range_end = start + len;
current->journal_info = dio_data;
}
/*
* In the case of write we need to clear and unlock the entire range,
* in the case of read we need to unlock only the end area that we
* aren't using if there is any left over space.
*/
if (lockstart < lockend) {
clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
lockend, unlock_bits, 1, 0,
&cached_state, GFP_NOFS);
} else {
free_extent_state(cached_state);
}
free_extent_map(em);
return 0;
unlock_err:
clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
unlock_bits, 1, 0, &cached_state, GFP_NOFS);
err:
if (dio_data)
current->journal_info = dio_data;
/*
* Compensate the delalloc release we do in btrfs_direct_IO() when we
* write less data then expected, so that we don't underflow our inode's
* outstanding extents counter.
*/
if (create && dio_data)
adjust_dio_outstanding_extents(inode, dio_data, len);
return ret;
}
static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
int rw, int mirror_num)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
BUG_ON(rw & REQ_WRITE);
bio_get(bio);
ret = btrfs_bio_wq_end_io(root->fs_info, bio,
BTRFS_WQ_ENDIO_DIO_REPAIR);
if (ret)
goto err;
ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
err:
bio_put(bio);
return ret;
}
static int btrfs_check_dio_repairable(struct inode *inode,
struct bio *failed_bio,
struct io_failure_record *failrec,
int failed_mirror)
{
int num_copies;
num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
failrec->logical, failrec->len);
if (num_copies == 1) {
/*
* we only have a single copy of the data, so don't bother with
* all the retry and error correction code that follows. no
* matter what the error is, it is very likely to persist.
*/
pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
num_copies, failrec->this_mirror, failed_mirror);
return 0;
}
failrec->failed_mirror = failed_mirror;
failrec->this_mirror++;
if (failrec->this_mirror == failed_mirror)
failrec->this_mirror++;
if (failrec->this_mirror > num_copies) {
pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
num_copies, failrec->this_mirror, failed_mirror);
return 0;
}
return 1;
}
static int dio_read_error(struct inode *inode, struct bio *failed_bio,
struct page *page, unsigned int pgoff,
u64 start, u64 end, int failed_mirror,
bio_end_io_t *repair_endio, void *repair_arg)
{
struct io_failure_record *failrec;
struct bio *bio;
int isector;
int read_mode;
int ret;
BUG_ON(failed_bio->bi_rw & REQ_WRITE);
ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
if (ret)
return ret;
ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
failed_mirror);
if (!ret) {
free_io_failure(inode, failrec);
return -EIO;
}
if ((failed_bio->bi_vcnt > 1)
|| (failed_bio->bi_io_vec->bv_len
> BTRFS_I(inode)->root->sectorsize))
read_mode = READ_SYNC | REQ_FAILFAST_DEV;
else
read_mode = READ_SYNC;
isector = start - btrfs_io_bio(failed_bio)->logical;
isector >>= inode->i_sb->s_blocksize_bits;
bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
pgoff, isector, repair_endio, repair_arg);
if (!bio) {
free_io_failure(inode, failrec);
return -EIO;
}
btrfs_debug(BTRFS_I(inode)->root->fs_info,
"Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
read_mode, failrec->this_mirror, failrec->in_validation);
ret = submit_dio_repair_bio(inode, bio, read_mode,
failrec->this_mirror);
if (ret) {
free_io_failure(inode, failrec);
bio_put(bio);
}
return ret;
}
struct btrfs_retry_complete {
struct completion done;
struct inode *inode;
u64 start;
int uptodate;
};
static void btrfs_retry_endio_nocsum(struct bio *bio)
{
struct btrfs_retry_complete *done = bio->bi_private;
struct inode *inode;
struct bio_vec *bvec;
int i;
if (bio->bi_error)
goto end;
ASSERT(bio->bi_vcnt == 1);
inode = bio->bi_io_vec->bv_page->mapping->host;
ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
done->uptodate = 1;
bio_for_each_segment_all(bvec, bio, i)
clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
end:
complete(&done->done);
bio_put(bio);
}
static int __btrfs_correct_data_nocsum(struct inode *inode,
struct btrfs_io_bio *io_bio)
{
struct btrfs_fs_info *fs_info;
struct bio_vec *bvec;
struct btrfs_retry_complete done;
u64 start;
unsigned int pgoff;
u32 sectorsize;
int nr_sectors;
int i;
int ret;
fs_info = BTRFS_I(inode)->root->fs_info;
sectorsize = BTRFS_I(inode)->root->sectorsize;
start = io_bio->logical;
done.inode = inode;
bio_for_each_segment_all(bvec, &io_bio->bio, i) {
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
pgoff = bvec->bv_offset;
next_block_or_try_again:
done.uptodate = 0;
done.start = start;
init_completion(&done.done);
ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
pgoff, start, start + sectorsize - 1,
io_bio->mirror_num,
btrfs_retry_endio_nocsum, &done);
if (ret)
return ret;
wait_for_completion(&done.done);
if (!done.uptodate) {
/* We might have another mirror, so try again */
goto next_block_or_try_again;
}
start += sectorsize;
if (nr_sectors--) {
pgoff += sectorsize;
goto next_block_or_try_again;
}
}
return 0;
}
static void btrfs_retry_endio(struct bio *bio)
{
struct btrfs_retry_complete *done = bio->bi_private;
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
struct inode *inode;
struct bio_vec *bvec;
u64 start;
int uptodate;
int ret;
int i;
if (bio->bi_error)
goto end;
uptodate = 1;
start = done->start;
ASSERT(bio->bi_vcnt == 1);
inode = bio->bi_io_vec->bv_page->mapping->host;
ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
bio_for_each_segment_all(bvec, bio, i) {
ret = __readpage_endio_check(done->inode, io_bio, i,
bvec->bv_page, bvec->bv_offset,
done->start, bvec->bv_len);
if (!ret)
clean_io_failure(done->inode, done->start,
bvec->bv_page, bvec->bv_offset);
else
uptodate = 0;
}
done->uptodate = uptodate;
end:
complete(&done->done);
bio_put(bio);
}
static int __btrfs_subio_endio_read(struct inode *inode,
struct btrfs_io_bio *io_bio, int err)
{
struct btrfs_fs_info *fs_info;
struct bio_vec *bvec;
struct btrfs_retry_complete done;
u64 start;
u64 offset = 0;
u32 sectorsize;
int nr_sectors;
unsigned int pgoff;
int csum_pos;
int i;
int ret;
fs_info = BTRFS_I(inode)->root->fs_info;
sectorsize = BTRFS_I(inode)->root->sectorsize;
err = 0;
start = io_bio->logical;
done.inode = inode;
bio_for_each_segment_all(bvec, &io_bio->bio, i) {
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
pgoff = bvec->bv_offset;
next_block:
csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
ret = __readpage_endio_check(inode, io_bio, csum_pos,
bvec->bv_page, pgoff, start,
sectorsize);
if (likely(!ret))
goto next;
try_again:
done.uptodate = 0;
done.start = start;
init_completion(&done.done);
ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
pgoff, start, start + sectorsize - 1,
io_bio->mirror_num,
btrfs_retry_endio, &done);
if (ret) {
err = ret;
goto next;
}
wait_for_completion(&done.done);
if (!done.uptodate) {
/* We might have another mirror, so try again */
goto try_again;
}
next:
offset += sectorsize;
start += sectorsize;
ASSERT(nr_sectors);
if (--nr_sectors) {
pgoff += sectorsize;
goto next_block;
}
}
return err;
}
static int btrfs_subio_endio_read(struct inode *inode,
struct btrfs_io_bio *io_bio, int err)
{
bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
if (skip_csum) {
if (unlikely(err))
return __btrfs_correct_data_nocsum(inode, io_bio);
else
return 0;
} else {
return __btrfs_subio_endio_read(inode, io_bio, err);
}
}
static void btrfs_endio_direct_read(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
struct inode *inode = dip->inode;
struct bio *dio_bio;
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
int err = bio->bi_error;
if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
err = btrfs_subio_endio_read(inode, io_bio, err);
unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
dip->logical_offset + dip->bytes - 1);
dio_bio = dip->dio_bio;
kfree(dip);
dio_bio->bi_error = bio->bi_error;
dio_end_io(dio_bio, bio->bi_error);
if (io_bio->end_io)
io_bio->end_io(io_bio, err);
bio_put(bio);
}
static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
const u64 offset,
const u64 bytes,
const int uptodate)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ordered_extent *ordered = NULL;
u64 ordered_offset = offset;
u64 ordered_bytes = bytes;
int ret;
again:
ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
&ordered_offset,
ordered_bytes,
uptodate);
if (!ret)
goto out_test;
btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
finish_ordered_fn, NULL, NULL);
btrfs_queue_work(root->fs_info->endio_write_workers,
&ordered->work);
out_test:
/*
* our bio might span multiple ordered extents. If we haven't
* completed the accounting for the whole dio, go back and try again
*/
if (ordered_offset < offset + bytes) {
ordered_bytes = offset + bytes - ordered_offset;
ordered = NULL;
goto again;
}
}
static void btrfs_endio_direct_write(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
struct bio *dio_bio = dip->dio_bio;
btrfs_endio_direct_write_update_ordered(dip->inode,
dip->logical_offset,
dip->bytes,
!bio->bi_error);
kfree(dip);
dio_bio->bi_error = bio->bi_error;
dio_end_io(dio_bio, bio->bi_error);
bio_put(bio);
}
static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
struct bio *bio, int mirror_num,
unsigned long bio_flags, u64 offset)
{
int ret;
struct btrfs_root *root = BTRFS_I(inode)->root;
ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
BUG_ON(ret); /* -ENOMEM */
return 0;
}
static void btrfs_end_dio_bio(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
int err = bio->bi_error;
if (err)
btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
"direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
btrfs_ino(dip->inode), bio->bi_rw,
(unsigned long long)bio->bi_iter.bi_sector,
bio->bi_iter.bi_size, err);
if (dip->subio_endio)
err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
if (err) {
dip->errors = 1;
/*
* before atomic variable goto zero, we must make sure
* dip->errors is perceived to be set.
*/
smp_mb__before_atomic();
}
/* if there are more bios still pending for this dio, just exit */
if (!atomic_dec_and_test(&dip->pending_bios))
goto out;
if (dip->errors) {
bio_io_error(dip->orig_bio);
} else {
dip->dio_bio->bi_error = 0;
bio_endio(dip->orig_bio);
}
out:
bio_put(bio);
}
static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
u64 first_sector, gfp_t gfp_flags)
{
struct bio *bio;
bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
if (bio)
bio_associate_current(bio);
return bio;
}
static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
struct inode *inode,
struct btrfs_dio_private *dip,
struct bio *bio,
u64 file_offset)
{
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
int ret;
/*
* We load all the csum data we need when we submit
* the first bio to reduce the csum tree search and
* contention.
*/
if (dip->logical_offset == file_offset) {
ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
file_offset);
if (ret)
return ret;
}
if (bio == dip->orig_bio)
return 0;
file_offset -= dip->logical_offset;
file_offset >>= inode->i_sb->s_blocksize_bits;
io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
return 0;
}
static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
int rw, u64 file_offset, int skip_sum,
int async_submit)
{
struct btrfs_dio_private *dip = bio->bi_private;
int write = rw & REQ_WRITE;
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret;
if (async_submit)
async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
bio_get(bio);
if (!write) {
ret = btrfs_bio_wq_end_io(root->fs_info, bio,
BTRFS_WQ_ENDIO_DATA);
if (ret)
goto err;
}
if (skip_sum)
goto map;
if (write && async_submit) {
ret = btrfs_wq_submit_bio(root->fs_info,
inode, rw, bio, 0, 0,
file_offset,
__btrfs_submit_bio_start_direct_io,
__btrfs_submit_bio_done);
goto err;
} else if (write) {
/*
* If we aren't doing async submit, calculate the csum of the
* bio now.
*/
ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
if (ret)
goto err;
} else {
ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
file_offset);
if (ret)
goto err;
}
map:
ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
err:
bio_put(bio);
return ret;
}
static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
int skip_sum)
{
struct inode *inode = dip->inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct bio *bio;
struct bio *orig_bio = dip->orig_bio;
struct bio_vec *bvec = orig_bio->bi_io_vec;
u64 start_sector = orig_bio->bi_iter.bi_sector;
u64 file_offset = dip->logical_offset;
u64 submit_len = 0;
u64 map_length;
u32 blocksize = root->sectorsize;
int async_submit = 0;
int nr_sectors;
int ret;
int i;
map_length = orig_bio->bi_iter.bi_size;
ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
&map_length, NULL, 0);
if (ret)
return -EIO;
if (map_length >= orig_bio->bi_iter.bi_size) {
bio = orig_bio;
dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
goto submit;
}
/* async crcs make it difficult to collect full stripe writes. */
if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
async_submit = 0;
else
async_submit = 1;
bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
if (!bio)
return -ENOMEM;
bio->bi_private = dip;
bio->bi_end_io = btrfs_end_dio_bio;
btrfs_io_bio(bio)->logical = file_offset;
atomic_inc(&dip->pending_bios);
while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
i = 0;
next_block:
if (unlikely(map_length < submit_len + blocksize ||
bio_add_page(bio, bvec->bv_page, blocksize,
bvec->bv_offset + (i * blocksize)) < blocksize)) {
/*
* inc the count before we submit the bio so
* we know the end IO handler won't happen before
* we inc the count. Otherwise, the dip might get freed
* before we're done setting it up
*/
atomic_inc(&dip->pending_bios);
ret = __btrfs_submit_dio_bio(bio, inode, rw,
file_offset, skip_sum,
async_submit);
if (ret) {
bio_put(bio);
atomic_dec(&dip->pending_bios);
goto out_err;
}
start_sector += submit_len >> 9;
file_offset += submit_len;
submit_len = 0;
bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
start_sector, GFP_NOFS);
if (!bio)
goto out_err;
bio->bi_private = dip;
bio->bi_end_io = btrfs_end_dio_bio;
btrfs_io_bio(bio)->logical = file_offset;
map_length = orig_bio->bi_iter.bi_size;
ret = btrfs_map_block(root->fs_info, rw,
start_sector << 9,
&map_length, NULL, 0);
if (ret) {
bio_put(bio);
goto out_err;
}
goto next_block;
} else {
submit_len += blocksize;
if (--nr_sectors) {
i++;
goto next_block;
}
bvec++;
}
}
submit:
ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
async_submit);
if (!ret)
return 0;
bio_put(bio);
out_err:
dip->errors = 1;
/*
* before atomic variable goto zero, we must
* make sure dip->errors is perceived to be set.
*/
smp_mb__before_atomic();
if (atomic_dec_and_test(&dip->pending_bios))
bio_io_error(dip->orig_bio);
/* bio_end_io() will handle error, so we needn't return it */
return 0;
}
static void btrfs_submit_direct(int rw, struct bio *dio_bio,
struct inode *inode, loff_t file_offset)
{
struct btrfs_dio_private *dip = NULL;
struct bio *io_bio = NULL;
struct btrfs_io_bio *btrfs_bio;
int skip_sum;
int write = rw & REQ_WRITE;
int ret = 0;
skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
if (!io_bio) {
ret = -ENOMEM;
goto free_ordered;
}
dip = kzalloc(sizeof(*dip), GFP_NOFS);
if (!dip) {
ret = -ENOMEM;
goto free_ordered;
}
dip->private = dio_bio->bi_private;
dip->inode = inode;
dip->logical_offset = file_offset;
dip->bytes = dio_bio->bi_iter.bi_size;
dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
io_bio->bi_private = dip;
dip->orig_bio = io_bio;
dip->dio_bio = dio_bio;
atomic_set(&dip->pending_bios, 0);
btrfs_bio = btrfs_io_bio(io_bio);
btrfs_bio->logical = file_offset;
if (write) {
io_bio->bi_end_io = btrfs_endio_direct_write;
} else {
io_bio->bi_end_io = btrfs_endio_direct_read;
dip->subio_endio = btrfs_subio_endio_read;
}
/*
* Reset the range for unsubmitted ordered extents (to a 0 length range)
* even if we fail to submit a bio, because in such case we do the
* corresponding error handling below and it must not be done a second
* time by btrfs_direct_IO().
*/
if (write) {
struct btrfs_dio_data *dio_data = current->journal_info;
dio_data->unsubmitted_oe_range_end = dip->logical_offset +
dip->bytes;
dio_data->unsubmitted_oe_range_start =
dio_data->unsubmitted_oe_range_end;
}
ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
if (!ret)
return;
if (btrfs_bio->end_io)
btrfs_bio->end_io(btrfs_bio, ret);
free_ordered:
/*
* If we arrived here it means either we failed to submit the dip
* or we either failed to clone the dio_bio or failed to allocate the
* dip. If we cloned the dio_bio and allocated the dip, we can just
* call bio_endio against our io_bio so that we get proper resource
* cleanup if we fail to submit the dip, otherwise, we must do the
* same as btrfs_endio_direct_[write|read] because we can't call these
* callbacks - they require an allocated dip and a clone of dio_bio.
*/
if (io_bio && dip) {
io_bio->bi_error = -EIO;
bio_endio(io_bio);
/*
* The end io callbacks free our dip, do the final put on io_bio
* and all the cleanup and final put for dio_bio (through
* dio_end_io()).
*/
dip = NULL;
io_bio = NULL;
} else {
if (write)
btrfs_endio_direct_write_update_ordered(inode,
file_offset,
dio_bio->bi_iter.bi_size,
0);
else
unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
file_offset + dio_bio->bi_iter.bi_size - 1);
dio_bio->bi_error = -EIO;
/*
* Releases and cleans up our dio_bio, no need to bio_put()
* nor bio_endio()/bio_io_error() against dio_bio.
*/
dio_end_io(dio_bio, ret);
}
if (io_bio)
bio_put(io_bio);
kfree(dip);
}
static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
const struct iov_iter *iter, loff_t offset)
{
int seg;
int i;
unsigned blocksize_mask = root->sectorsize - 1;
ssize_t retval = -EINVAL;
if (offset & blocksize_mask)
goto out;
if (iov_iter_alignment(iter) & blocksize_mask)
goto out;
/* If this is a write we don't need to check anymore */
if (iov_iter_rw(iter) == WRITE)
return 0;
/*
* Check to make sure we don't have duplicate iov_base's in this
* iovec, if so return EINVAL, otherwise we'll get csum errors
* when reading back.
*/
for (seg = 0; seg < iter->nr_segs; seg++) {
for (i = seg + 1; i < iter->nr_segs; i++) {
if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
goto out;
}
}
retval = 0;
out:
return retval;
}
static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
loff_t offset)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_dio_data dio_data = { 0 };
size_t count = 0;
int flags = 0;
bool wakeup = true;
bool relock = false;
ssize_t ret;
if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
return 0;
inode_dio_begin(inode);
smp_mb__after_atomic();
/*
* The generic stuff only does filemap_write_and_wait_range, which
* isn't enough if we've written compressed pages to this area, so
* we need to flush the dirty pages again to make absolutely sure
* that any outstanding dirty pages are on disk.
*/
count = iov_iter_count(iter);
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags))
filemap_fdatawrite_range(inode->i_mapping, offset,
offset + count - 1);
if (iov_iter_rw(iter) == WRITE) {
/*
* If the write DIO is beyond the EOF, we need update
* the isize, but it is protected by i_mutex. So we can
* not unlock the i_mutex at this case.
*/
if (offset + count <= inode->i_size) {
inode_unlock(inode);
relock = true;
}
ret = btrfs_delalloc_reserve_space(inode, offset, count);
if (ret)
goto out;
dio_data.outstanding_extents = div64_u64(count +
BTRFS_MAX_EXTENT_SIZE - 1,
BTRFS_MAX_EXTENT_SIZE);
/*
* We need to know how many extents we reserved so that we can
* do the accounting properly if we go over the number we
* originally calculated. Abuse current->journal_info for this.
*/
dio_data.reserve = round_up(count, root->sectorsize);
dio_data.unsubmitted_oe_range_start = (u64)offset;
dio_data.unsubmitted_oe_range_end = (u64)offset;
current->journal_info = &dio_data;
} else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
&BTRFS_I(inode)->runtime_flags)) {
inode_dio_end(inode);
flags = DIO_LOCKING | DIO_SKIP_HOLES;
wakeup = false;
}
ret = __blockdev_direct_IO(iocb, inode,
BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
iter, offset, btrfs_get_blocks_direct, NULL,
btrfs_submit_direct, flags);
if (iov_iter_rw(iter) == WRITE) {
current->journal_info = NULL;
if (ret < 0 && ret != -EIOCBQUEUED) {
if (dio_data.reserve)
btrfs_delalloc_release_space(inode, offset,
dio_data.reserve);
/*
* On error we might have left some ordered extents
* without submitting corresponding bios for them, so
* cleanup them up to avoid other tasks getting them
* and waiting for them to complete forever.
*/
if (dio_data.unsubmitted_oe_range_start <
dio_data.unsubmitted_oe_range_end)
btrfs_endio_direct_write_update_ordered(inode,
dio_data.unsubmitted_oe_range_start,
dio_data.unsubmitted_oe_range_end -
dio_data.unsubmitted_oe_range_start,
0);
} else if (ret >= 0 && (size_t)ret < count)
btrfs_delalloc_release_space(inode, offset,
count - (size_t)ret);
}
out:
if (wakeup)
inode_dio_end(inode);
if (relock)
inode_lock(inode);
return ret;
}
#define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len)
{
int ret;
ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
if (ret)
return ret;
return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
}
int btrfs_readpage(struct file *file, struct page *page)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_read_full_page(tree, page, btrfs_get_extent, 0);
}
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct extent_io_tree *tree;
struct inode *inode = page->mapping->host;
int ret;
if (current->flags & PF_MEMALLOC) {
redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
/*
* If we are under memory pressure we will call this directly from the
* VM, we need to make sure we have the inode referenced for the ordered
* extent. If not just return like we didn't do anything.
*/
if (!igrab(inode)) {
redirty_page_for_writepage(wbc, page);
return AOP_WRITEPAGE_ACTIVATE;
}
tree = &BTRFS_I(page->mapping->host)->io_tree;
ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
btrfs_add_delayed_iput(inode);
return ret;
}
static int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(mapping->host)->io_tree;
return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
}
static int
btrfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(mapping->host)->io_tree;
return extent_readpages(tree, mapping, pages, nr_pages,
btrfs_get_extent);
}
static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
struct extent_io_tree *tree;
struct extent_map_tree *map;
int ret;
tree = &BTRFS_I(page->mapping->host)->io_tree;
map = &BTRFS_I(page->mapping->host)->extent_tree;
ret = try_release_extent_mapping(map, tree, page, gfp_flags);
if (ret == 1) {
ClearPagePrivate(page);
set_page_private(page, 0);
put_page(page);
}
return ret;
}
static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
if (PageWriteback(page) || PageDirty(page))
return 0;
return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
}
static void btrfs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
struct inode *inode = page->mapping->host;
struct extent_io_tree *tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
u64 page_start = page_offset(page);
u64 page_end = page_start + PAGE_SIZE - 1;
u64 start;
u64 end;
int inode_evicting = inode->i_state & I_FREEING;
/*
* we have the page locked, so new writeback can't start,
* and the dirty bit won't be cleared while we are here.
*
* Wait for IO on this page so that we can safely clear
* the PagePrivate2 bit and do ordered accounting
*/
wait_on_page_writeback(page);
tree = &BTRFS_I(inode)->io_tree;
if (offset) {
btrfs_releasepage(page, GFP_NOFS);
return;
}
if (!inode_evicting)
lock_extent_bits(tree, page_start, page_end, &cached_state);
again:
start = page_start;
ordered = btrfs_lookup_ordered_range(inode, start,
page_end - start + 1);
if (ordered) {
end = min(page_end, ordered->file_offset + ordered->len - 1);
/*
* IO on this page will never be started, so we need
* to account for any ordered extents now
*/
if (!inode_evicting)
clear_extent_bit(tree, start, end,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 1, 0, &cached_state,
GFP_NOFS);
/*
* whoever cleared the private bit is responsible
* for the finish_ordered_io
*/
if (TestClearPagePrivate2(page)) {
struct btrfs_ordered_inode_tree *tree;
u64 new_len;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
new_len = start - ordered->file_offset;
if (new_len < ordered->truncated_len)
ordered->truncated_len = new_len;
spin_unlock_irq(&tree->lock);
if (btrfs_dec_test_ordered_pending(inode, &ordered,
start,
end - start + 1, 1))
btrfs_finish_ordered_io(ordered);
}
btrfs_put_ordered_extent(ordered);
if (!inode_evicting) {
cached_state = NULL;
lock_extent_bits(tree, start, end,
&cached_state);
}
start = end + 1;
if (start < page_end)
goto again;
}
/*
* Qgroup reserved space handler
* Page here will be either
* 1) Already written to disk
* In this case, its reserved space is released from data rsv map
* and will be freed by delayed_ref handler finally.
* So even we call qgroup_free_data(), it won't decrease reserved
* space.
* 2) Not written to disk
* This means the reserved space should be freed here.
*/
btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
if (!inode_evicting) {
clear_extent_bit(tree, page_start, page_end,
EXTENT_LOCKED | EXTENT_DIRTY |
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 1, 1,
&cached_state, GFP_NOFS);
__btrfs_releasepage(page, GFP_NOFS);
}
ClearPageChecked(page);
if (PagePrivate(page)) {
ClearPagePrivate(page);
set_page_private(page, 0);
put_page(page);
}
}
/*
* btrfs_page_mkwrite() is not allowed to change the file size as it gets
* called from a page fault handler when a page is first dirtied. Hence we must
* be careful to check for EOF conditions here. We set the page up correctly
* for a written page which means we get ENOSPC checking when writing into
* holes and correct delalloc and unwritten extent mapping on filesystems that
* support these features.
*
* We are not allowed to take the i_mutex here so we have to play games to
* protect against truncate races as the page could now be beyond EOF. Because
* vmtruncate() writes the inode size before removing pages, once we have the
* page lock we can determine safely if the page is beyond EOF. If it is not
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = file_inode(vma->vm_file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
char *kaddr;
unsigned long zero_start;
loff_t size;
int ret;
int reserved = 0;
u64 reserved_space;
u64 page_start;
u64 page_end;
u64 end;
reserved_space = PAGE_SIZE;
sb_start_pagefault(inode->i_sb);
page_start = page_offset(page);
page_end = page_start + PAGE_SIZE - 1;
end = page_end;
/*
* Reserving delalloc space after obtaining the page lock can lead to
* deadlock. For example, if a dirty page is locked by this function
* and the call to btrfs_delalloc_reserve_space() ends up triggering
* dirty page write out, then the btrfs_writepage() function could
* end up waiting indefinitely to get a lock on the page currently
* being processed by btrfs_page_mkwrite() function.
*/
ret = btrfs_delalloc_reserve_space(inode, page_start,
reserved_space);
if (!ret) {
ret = file_update_time(vma->vm_file);
reserved = 1;
}
if (ret) {
if (ret == -ENOMEM)
ret = VM_FAULT_OOM;
else /* -ENOSPC, -EIO, etc */
ret = VM_FAULT_SIGBUS;
if (reserved)
goto out;
goto out_noreserve;
}
ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
again:
lock_page(page);
size = i_size_read(inode);
if ((page->mapping != inode->i_mapping) ||
(page_start >= size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
wait_on_page_writeback(page);
lock_extent_bits(io_tree, page_start, page_end, &cached_state);
set_page_extent_mapped(page);
/*
* we can't set the delalloc bits if there are pending ordered
* extents. Drop our locks and wait for them to finish
*/
ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
if (ordered) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
if (page->index == ((size - 1) >> PAGE_SHIFT)) {
reserved_space = round_up(size - page_start, root->sectorsize);
if (reserved_space < PAGE_SIZE) {
end = page_start + reserved_space - 1;
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents++;
spin_unlock(&BTRFS_I(inode)->lock);
btrfs_delalloc_release_space(inode, page_start,
PAGE_SIZE - reserved_space);
}
}
/*
* XXX - page_mkwrite gets called every time the page is dirtied, even
* if it was already dirty, so for space accounting reasons we need to
* clear any delalloc bits for the range we are fixing to save. There
* is probably a better way to do this, but for now keep consistent with
* prepare_pages in the normal write path.
*/
clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, &cached_state, GFP_NOFS);
ret = btrfs_set_extent_delalloc(inode, page_start, end,
&cached_state);
if (ret) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state, GFP_NOFS);
ret = VM_FAULT_SIGBUS;
goto out_unlock;
}
ret = 0;
/* page is wholly or partially inside EOF */
if (page_start + PAGE_SIZE > size)
zero_start = size & ~PAGE_MASK;
else
zero_start = PAGE_SIZE;
if (zero_start != PAGE_SIZE) {
kaddr = kmap(page);
memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
flush_dcache_page(page);
kunmap(page);
}
ClearPageChecked(page);
set_page_dirty(page);
SetPageUptodate(page);
BTRFS_I(inode)->last_trans = root->fs_info->generation;
BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
out_unlock:
if (!ret) {
sb_end_pagefault(inode->i_sb);
return VM_FAULT_LOCKED;
}
unlock_page(page);
out:
btrfs_delalloc_release_space(inode, page_start, reserved_space);
out_noreserve:
sb_end_pagefault(inode->i_sb);
return ret;
}
static int btrfs_truncate(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv;
int ret = 0;
int err = 0;
struct btrfs_trans_handle *trans;
u64 mask = root->sectorsize - 1;
u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
(u64)-1);
if (ret)
return ret;
/*
* Yes ladies and gentelment, this is indeed ugly. The fact is we have
* 3 things going on here
*
* 1) We need to reserve space for our orphan item and the space to
* delete our orphan item. Lord knows we don't want to have a dangling
* orphan item because we didn't reserve space to remove it.
*
* 2) We need to reserve space to update our inode.
*
* 3) We need to have something to cache all the space that is going to
* be free'd up by the truncate operation, but also have some slack
* space reserved in case it uses space during the truncate (thank you
* very much snapshotting).
*
* And we need these to all be seperate. The fact is we can use alot of
* space doing the truncate, and we have no earthly idea how much space
* we will use, so we need the truncate reservation to be seperate so it
* doesn't end up using space reserved for updating the inode or
* removing the orphan item. We also need to be able to stop the
* transaction and start a new one, which means we need to be able to
* update the inode several times, and we have no idea of knowing how
* many times that will be, so we can't just reserve 1 item for the
* entirety of the opration, so that has to be done seperately as well.
* Then there is the orphan item, which does indeed need to be held on
* to for the whole operation, and we need nobody to touch this reserved
* space except the orphan code.
*
* So that leaves us with
*
* 1) root->orphan_block_rsv - for the orphan deletion.
* 2) rsv - for the truncate reservation, which we will steal from the
* transaction reservation.
* 3) fs_info->trans_block_rsv - this will have 1 items worth left for
* updating the inode.
*/
rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
if (!rsv)
return -ENOMEM;
rsv->size = min_size;
rsv->failfast = 1;
/*
* 1 for the truncate slack space
* 1 for updating the inode.
*/
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out;
}
/* Migrate the slack space for the truncate to our reserve */
ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
min_size);
BUG_ON(ret);
/*
* So if we truncate and then write and fsync we normally would just
* write the extents that changed, which is a problem if we need to
* first truncate that entire inode. So set this flag so we write out
* all of the extents in the inode to the sync log so we're completely
* safe.
*/
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
trans->block_rsv = rsv;
while (1) {
ret = btrfs_truncate_inode_items(trans, root, inode,
inode->i_size,
BTRFS_EXTENT_DATA_KEY);
if (ret != -ENOSPC && ret != -EAGAIN) {
err = ret;
break;
}
trans->block_rsv = &root->fs_info->trans_block_rsv;
ret = btrfs_update_inode(trans, root, inode);
if (ret) {
err = ret;
break;
}
btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
ret = err = PTR_ERR(trans);
trans = NULL;
break;
}
ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
rsv, min_size);
BUG_ON(ret); /* shouldn't happen */
trans->block_rsv = rsv;
}
if (ret == 0 && inode->i_nlink > 0) {
trans->block_rsv = root->orphan_block_rsv;
ret = btrfs_orphan_del(trans, inode);
if (ret)
err = ret;
}
if (trans) {
trans->block_rsv = &root->fs_info->trans_block_rsv;
ret = btrfs_update_inode(trans, root, inode);
if (ret && !err)
err = ret;
ret = btrfs_end_transaction(trans, root);
btrfs_btree_balance_dirty(root);
}
out:
btrfs_free_block_rsv(root, rsv);
if (ret && !err)
err = ret;
return err;
}
/*
* create a new subvolume directory/inode (helper for the ioctl).
*/
int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
struct btrfs_root *new_root,
struct btrfs_root *parent_root,
u64 new_dirid)
{
struct inode *inode;
int err;
u64 index = 0;
inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
new_dirid, new_dirid,
S_IFDIR | (~current_umask() & S_IRWXUGO),
&index);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
set_nlink(inode, 1);
btrfs_i_size_write(inode, 0);
unlock_new_inode(inode);
err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
if (err)
btrfs_err(new_root->fs_info,
"error inheriting subvolume %llu properties: %d",
new_root->root_key.objectid, err);
err = btrfs_update_inode(trans, new_root, inode);
iput(inode);
return err;
}
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
struct btrfs_inode *ei;
struct inode *inode;
ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
if (!ei)
return NULL;
ei->root = NULL;
ei->generation = 0;
ei->last_trans = 0;
ei->last_sub_trans = 0;
ei->logged_trans = 0;
ei->delalloc_bytes = 0;
ei->defrag_bytes = 0;
ei->disk_i_size = 0;
ei->flags = 0;
ei->csum_bytes = 0;
ei->index_cnt = (u64)-1;
ei->dir_index = 0;
ei->last_unlink_trans = 0;
ei->last_log_commit = 0;
ei->delayed_iput_count = 0;
spin_lock_init(&ei->lock);
ei->outstanding_extents = 0;
ei->reserved_extents = 0;
ei->runtime_flags = 0;
ei->force_compress = BTRFS_COMPRESS_NONE;
ei->delayed_node = NULL;
ei->i_otime.tv_sec = 0;
ei->i_otime.tv_nsec = 0;
inode = &ei->vfs_inode;
extent_map_tree_init(&ei->extent_tree);
extent_io_tree_init(&ei->io_tree, &inode->i_data);
extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
ei->io_tree.track_uptodate = 1;
ei->io_failure_tree.track_uptodate = 1;
atomic_set(&ei->sync_writers, 0);
mutex_init(&ei->log_mutex);
mutex_init(&ei->delalloc_mutex);
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
INIT_LIST_HEAD(&ei->delalloc_inodes);
INIT_LIST_HEAD(&ei->delayed_iput);
RB_CLEAR_NODE(&ei->rb_node);
return inode;
}
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_destroy_inode(struct inode *inode)
{
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
#endif
static void btrfs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
void btrfs_destroy_inode(struct inode *inode)
{
struct btrfs_ordered_extent *ordered;
struct btrfs_root *root = BTRFS_I(inode)->root;
WARN_ON(!hlist_empty(&inode->i_dentry));
WARN_ON(inode->i_data.nrpages);
WARN_ON(BTRFS_I(inode)->outstanding_extents);
WARN_ON(BTRFS_I(inode)->reserved_extents);
WARN_ON(BTRFS_I(inode)->delalloc_bytes);
WARN_ON(BTRFS_I(inode)->csum_bytes);
WARN_ON(BTRFS_I(inode)->defrag_bytes);
/*
* This can happen where we create an inode, but somebody else also
* created the same inode and we need to destroy the one we already
* created.
*/
if (!root)
goto free;
if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
&BTRFS_I(inode)->runtime_flags)) {
btrfs_info(root->fs_info, "inode %llu still on the orphan list",
btrfs_ino(inode));
atomic_dec(&root->orphan_inodes);
}
while (1) {
ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
if (!ordered)
break;
else {
btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
ordered->file_offset, ordered->len);
btrfs_remove_ordered_extent(inode, ordered);
btrfs_put_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
}
}
btrfs_qgroup_check_reserved_leak(inode);
inode_tree_del(inode);
btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
free:
call_rcu(&inode->i_rcu, btrfs_i_callback);
}
int btrfs_drop_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
if (root == NULL)
return 1;
/* the snap/subvol tree is on deleting */
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
else
return generic_drop_inode(inode);
}
static void init_once(void *foo)
{
struct btrfs_inode *ei = (struct btrfs_inode *) foo;
inode_init_once(&ei->vfs_inode);
}
void btrfs_destroy_cachep(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(btrfs_inode_cachep);
kmem_cache_destroy(btrfs_trans_handle_cachep);
kmem_cache_destroy(btrfs_transaction_cachep);
kmem_cache_destroy(btrfs_path_cachep);
kmem_cache_destroy(btrfs_free_space_cachep);
}
int btrfs_init_cachep(void)
{
btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
sizeof(struct btrfs_inode), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
init_once);
if (!btrfs_inode_cachep)
goto fail;
btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
sizeof(struct btrfs_trans_handle), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_trans_handle_cachep)
goto fail;
btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
sizeof(struct btrfs_transaction), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_transaction_cachep)
goto fail;
btrfs_path_cachep = kmem_cache_create("btrfs_path",
sizeof(struct btrfs_path), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_path_cachep)
goto fail;
btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
sizeof(struct btrfs_free_space), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
if (!btrfs_free_space_cachep)
goto fail;
return 0;
fail:
btrfs_destroy_cachep();
return -ENOMEM;
}
static int btrfs_getattr(struct vfsmount *mnt,
struct dentry *dentry, struct kstat *stat)
{
u64 delalloc_bytes;
struct inode *inode = d_inode(dentry);
u32 blocksize = inode->i_sb->s_blocksize;
generic_fillattr(inode, stat);
stat->dev = BTRFS_I(inode)->root->anon_dev;
spin_lock(&BTRFS_I(inode)->lock);
delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
spin_unlock(&BTRFS_I(inode)->lock);
stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
ALIGN(delalloc_bytes, blocksize)) >> 9;
return 0;
}
static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct btrfs_root *dest = BTRFS_I(new_dir)->root;
struct inode *new_inode = d_inode(new_dentry);
struct inode *old_inode = d_inode(old_dentry);
u64 index = 0;
u64 root_objectid;
int ret;
u64 old_ino = btrfs_ino(old_inode);
if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return -EPERM;
/* we only allow rename subvolume link between subvolumes */
if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
return -EXDEV;
if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
(new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
return -ENOTEMPTY;
if (S_ISDIR(old_inode->i_mode) && new_inode &&
new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
/* check for collisions, even if the name isn't there */
ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
new_dentry->d_name.name,
new_dentry->d_name.len);
if (ret) {
if (ret == -EEXIST) {
/* we shouldn't get
* eexist without a new_inode */
if (WARN_ON(!new_inode)) {
return ret;
}
} else {
/* maybe -EOVERFLOW */
return ret;
}
}
ret = 0;
/*
* we're using rename to replace one file with another. Start IO on it
* now so we don't add too much work to the end of the transaction
*/
if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
filemap_flush(old_inode->i_mapping);
/* close the racy window with snapshot create/destroy ioctl */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&root->fs_info->subvol_sem);
/*
* We want to reserve the absolute worst case amount of items. So if
* both inodes are subvols and we need to unlink them then that would
* require 4 item modifications, but if they are both normal inodes it
* would require 5 item modifications, so we'll assume their normal
* inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
* should cover the worst case number of items we'll modify.
*/
trans = btrfs_start_transaction(root, 11);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_notrans;
}
if (dest != root)
btrfs_record_root_in_trans(trans, dest);
ret = btrfs_set_inode_index(new_dir, &index);
if (ret)
goto out_fail;
BTRFS_I(old_inode)->dir_index = 0ULL;
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(root->fs_info, trans);
} else {
ret = btrfs_insert_inode_ref(trans, dest,
new_dentry->d_name.name,
new_dentry->d_name.len,
old_ino,
btrfs_ino(new_dir), index);
if (ret)
goto out_fail;
/*
* this is an ugly little race, but the rename is required
* to make sure that if we crash, the inode is either at the
* old name or the new one. pinning the log transaction lets
* us make sure we don't allow a log commit to come in after
* we unlink the name but before we add the new name back in.
*/
btrfs_pin_log_trans(root);
}
inode_inc_iversion(old_dir);
inode_inc_iversion(new_dir);
inode_inc_iversion(old_inode);
old_dir->i_ctime = old_dir->i_mtime =
new_dir->i_ctime = new_dir->i_mtime =
old_inode->i_ctime = current_fs_time(old_dir->i_sb);
if (old_dentry->d_parent != new_dentry->d_parent)
btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
old_dentry->d_name.name,
old_dentry->d_name.len);
} else {
ret = __btrfs_unlink_inode(trans, root, old_dir,
d_inode(old_dentry),
old_dentry->d_name.name,
old_dentry->d_name.len);
if (!ret)
ret = btrfs_update_inode(trans, root, old_inode);
}
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_fail;
}
if (new_inode) {
inode_inc_iversion(new_inode);
new_inode->i_ctime = current_fs_time(new_inode->i_sb);
if (unlikely(btrfs_ino(new_inode) ==
BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
root_objectid = BTRFS_I(new_inode)->location.objectid;
ret = btrfs_unlink_subvol(trans, dest, new_dir,
root_objectid,
new_dentry->d_name.name,
new_dentry->d_name.len);
BUG_ON(new_inode->i_nlink == 0);
} else {
ret = btrfs_unlink_inode(trans, dest, new_dir,
d_inode(new_dentry),
new_dentry->d_name.name,
new_dentry->d_name.len);
}
if (!ret && new_inode->i_nlink == 0)
ret = btrfs_orphan_add(trans, d_inode(new_dentry));
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_fail;
}
}
ret = btrfs_add_link(trans, new_dir, old_inode,
new_dentry->d_name.name,
new_dentry->d_name.len, 0, index);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
goto out_fail;
}
if (old_inode->i_nlink == 1)
BTRFS_I(old_inode)->dir_index = index;
if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
struct dentry *parent = new_dentry->d_parent;
btrfs_log_new_name(trans, old_inode, old_dir, parent);
btrfs_end_log_trans(root);
}
out_fail:
btrfs_end_transaction(trans, root);
out_notrans:
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&root->fs_info->subvol_sem);
return ret;
}
static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
if (flags & ~RENAME_NOREPLACE)
return -EINVAL;
return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
}
static void btrfs_run_delalloc_work(struct btrfs_work *work)
{
struct btrfs_delalloc_work *delalloc_work;
struct inode *inode;
delalloc_work = container_of(work, struct btrfs_delalloc_work,
work);
inode = delalloc_work->inode;
filemap_flush(inode->i_mapping);
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags))
filemap_flush(inode->i_mapping);
if (delalloc_work->delay_iput)
btrfs_add_delayed_iput(inode);
else
iput(inode);
complete(&delalloc_work->completion);
}
struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
int delay_iput)
{
struct btrfs_delalloc_work *work;
work = kmalloc(sizeof(*work), GFP_NOFS);
if (!work)
return NULL;
init_completion(&work->completion);
INIT_LIST_HEAD(&work->list);
work->inode = inode;
work->delay_iput = delay_iput;
WARN_ON_ONCE(!inode);
btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
btrfs_run_delalloc_work, NULL, NULL);
return work;
}
void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
{
wait_for_completion(&work->completion);
kfree(work);
}
/*
* some fairly slow code that needs optimization. This walks the list
* of all the inodes with pending delalloc and forces them to disk.
*/
static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
int nr)
{
struct btrfs_inode *binode;
struct inode *inode;
struct btrfs_delalloc_work *work, *next;
struct list_head works;
struct list_head splice;
int ret = 0;
INIT_LIST_HEAD(&works);
INIT_LIST_HEAD(&splice);
mutex_lock(&root->delalloc_mutex);
spin_lock(&root->delalloc_lock);
list_splice_init(&root->delalloc_inodes, &splice);
while (!list_empty(&splice)) {
binode = list_entry(splice.next, struct btrfs_inode,
delalloc_inodes);
list_move_tail(&binode->delalloc_inodes,
&root->delalloc_inodes);
inode = igrab(&binode->vfs_inode);
if (!inode) {
cond_resched_lock(&root->delalloc_lock);
continue;
}
spin_unlock(&root->delalloc_lock);
work = btrfs_alloc_delalloc_work(inode, delay_iput);
if (!work) {
if (delay_iput)
btrfs_add_delayed_iput(inode);
else
iput(inode);
ret = -ENOMEM;
goto out;
}
list_add_tail(&work->list, &works);
btrfs_queue_work(root->fs_info->flush_workers,
&work->work);
ret++;
if (nr != -1 && ret >= nr)
goto out;
cond_resched();
spin_lock(&root->delalloc_lock);
}
spin_unlock(&root->delalloc_lock);
out:
list_for_each_entry_safe(work, next, &works, list) {
list_del_init(&work->list);
btrfs_wait_and_free_delalloc_work(work);
}
if (!list_empty_careful(&splice)) {
spin_lock(&root->delalloc_lock);
list_splice_tail(&splice, &root->delalloc_inodes);
spin_unlock(&root->delalloc_lock);
}
mutex_unlock(&root->delalloc_mutex);
return ret;
}
int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
{
int ret;
if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
return -EROFS;
ret = __start_delalloc_inodes(root, delay_iput, -1);
if (ret > 0)
ret = 0;
/*
* the filemap_flush will queue IO into the worker threads, but
* we have to make sure the IO is actually started and that
* ordered extents get created before we return
*/
atomic_inc(&root->fs_info->async_submit_draining);
while (atomic_read(&root->fs_info->nr_async_submits) ||
atomic_read(&root->fs_info->async_delalloc_pages)) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->nr_async_submits) == 0 &&
atomic_read(&root->fs_info->async_delalloc_pages) == 0));
}
atomic_dec(&root->fs_info->async_submit_draining);
return ret;
}
int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
int nr)
{
struct btrfs_root *root;
struct list_head splice;
int ret;
if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
return -EROFS;
INIT_LIST_HEAD(&splice);
mutex_lock(&fs_info->delalloc_root_mutex);
spin_lock(&fs_info->delalloc_root_lock);
list_splice_init(&fs_info->delalloc_roots, &splice);
while (!list_empty(&splice) && nr) {
root = list_first_entry(&splice, struct btrfs_root,
delalloc_root);
root = btrfs_grab_fs_root(root);
BUG_ON(!root);
list_move_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
ret = __start_delalloc_inodes(root, delay_iput, nr);
btrfs_put_fs_root(root);
if (ret < 0)
goto out;
if (nr != -1) {
nr -= ret;
WARN_ON(nr < 0);
}
spin_lock(&fs_info->delalloc_root_lock);
}
spin_unlock(&fs_info->delalloc_root_lock);
ret = 0;
atomic_inc(&fs_info->async_submit_draining);
while (atomic_read(&fs_info->nr_async_submits) ||
atomic_read(&fs_info->async_delalloc_pages)) {
wait_event(fs_info->async_submit_wait,
(atomic_read(&fs_info->nr_async_submits) == 0 &&
atomic_read(&fs_info->async_delalloc_pages) == 0));
}
atomic_dec(&fs_info->async_submit_draining);
out:
if (!list_empty_careful(&splice)) {
spin_lock(&fs_info->delalloc_root_lock);
list_splice_tail(&splice, &fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
mutex_unlock(&fs_info->delalloc_root_mutex);
return ret;
}
static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct inode *inode = NULL;
int err;
int drop_inode = 0;
u64 objectid;
u64 index = 0;
int name_len;
int datasize;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
struct extent_buffer *leaf;
name_len = strlen(symname);
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
return -ENAMETOOLONG;
/*
* 2 items for inode item and ref
* 2 items for dir items
* 1 item for updating parent inode item
* 1 item for the inline extent item
* 1 item for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 7);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(dir), objectid,
S_IFLNK|S_IRWXUGO, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock_inode;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out_unlock_inode;
}
key.objectid = btrfs_ino(inode);
key.offset = 0;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(name_len);
err = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (err) {
btrfs_free_path(path);
goto out_unlock_inode;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei,
BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_compression(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
ptr = btrfs_file_extent_inline_start(ei);
write_extent_buffer(leaf, symname, ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
inode->i_op = &btrfs_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &btrfs_symlink_aops;
inode_set_bytes(inode, name_len);
btrfs_i_size_write(inode, name_len);
err = btrfs_update_inode(trans, root, inode);
/*
* Last step, add directory indexes for our symlink inode. This is the
* last step to avoid extra cleanup of these indexes if an error happens
* elsewhere above.
*/
if (!err)
err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
if (err) {
drop_inode = 1;
goto out_unlock_inode;
}
unlock_new_inode(inode);
d_instantiate(dentry, inode);
out_unlock:
btrfs_end_transaction(trans, root);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(root);
return err;
out_unlock_inode:
drop_inode = 1;
unlock_new_inode(inode);
goto out_unlock;
}
static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint,
struct btrfs_trans_handle *trans)
{
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key ins;
u64 cur_offset = start;
u64 i_size;
u64 cur_bytes;
u64 last_alloc = (u64)-1;
int ret = 0;
bool own_trans = true;
if (trans)
own_trans = false;
while (num_bytes > 0) {
if (own_trans) {
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
}
cur_bytes = min_t(u64, num_bytes, SZ_256M);
cur_bytes = max(cur_bytes, min_size);
/*
* If we are severely fragmented we could end up with really
* small allocations, so if the allocator is returning small
* chunks lets make its job easier by only searching for those
* sized chunks.
*/
cur_bytes = min(cur_bytes, last_alloc);
ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
*alloc_hint, &ins, 1, 0);
if (ret) {
if (own_trans)
btrfs_end_transaction(trans, root);
break;
}
last_alloc = ins.offset;
ret = insert_reserved_file_extent(trans, inode,
cur_offset, ins.objectid,
ins.offset, ins.offset,
ins.offset, 0, 0, 0,
BTRFS_FILE_EXTENT_PREALLOC);
if (ret) {
btrfs_free_reserved_extent(root, ins.objectid,
ins.offset, 0);
btrfs_abort_transaction(trans, root, ret);
if (own_trans)
btrfs_end_transaction(trans, root);
break;
}
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + ins.offset -1, 0);
em = alloc_extent_map();
if (!em) {
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
goto next;
}
em->start = cur_offset;
em->orig_start = cur_offset;
em->len = ins.offset;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = ins.offset;
em->bdev = root->fs_info->fs_devices->latest_bdev;
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
em->generation = trans->transid;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST)
break;
btrfs_drop_extent_cache(inode, cur_offset,
cur_offset + ins.offset - 1,
0);
}
free_extent_map(em);
next:
num_bytes -= ins.offset;
cur_offset += ins.offset;
*alloc_hint = ins.objectid + ins.offset;
inode_inc_iversion(inode);
inode->i_ctime = current_fs_time(inode->i_sb);
BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
(actual_len > inode->i_size) &&
(cur_offset > inode->i_size)) {
if (cur_offset > actual_len)
i_size = actual_len;
else
i_size = cur_offset;
i_size_write(inode, i_size);
btrfs_ordered_update_i_size(inode, i_size, NULL);
}
ret = btrfs_update_inode(trans, root, inode);
if (ret) {
btrfs_abort_transaction(trans, root, ret);
if (own_trans)
btrfs_end_transaction(trans, root);
break;
}
if (own_trans)
btrfs_end_transaction(trans, root);
}
return ret;
}
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint,
NULL);
}
int btrfs_prealloc_file_range_trans(struct inode *inode,
struct btrfs_trans_handle *trans, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint, trans);
}
static int btrfs_set_page_dirty(struct page *page)
{
return __set_page_dirty_nobuffers(page);
}
static int btrfs_permission(struct inode *inode, int mask)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
umode_t mode = inode->i_mode;
if (mask & MAY_WRITE &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
if (btrfs_root_readonly(root))
return -EROFS;
if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
return -EACCES;
}
return generic_permission(inode, mask);
}
static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
u64 objectid;
u64 index;
int ret = 0;
/*
* 5 units required for adding orphan entry
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_find_free_ino(root, &objectid);
if (ret)
goto out;
inode = btrfs_new_inode(trans, root, dir, NULL, 0,
btrfs_ino(dir), objectid, mode, &index);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
inode = NULL;
goto out;
}
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
ret = btrfs_init_inode_security(trans, inode, dir, NULL);
if (ret)
goto out_inode;
ret = btrfs_update_inode(trans, root, inode);
if (ret)
goto out_inode;
ret = btrfs_orphan_add(trans, inode);
if (ret)
goto out_inode;
/*
* We set number of links to 0 in btrfs_new_inode(), and here we set
* it to 1 because d_tmpfile() will issue a warning if the count is 0,
* through:
*
* d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
*/
set_nlink(inode, 1);
unlock_new_inode(inode);
d_tmpfile(dentry, inode);
mark_inode_dirty(inode);
out:
btrfs_end_transaction(trans, root);
if (ret)
iput(inode);
btrfs_balance_delayed_items(root);
btrfs_btree_balance_dirty(root);
return ret;
out_inode:
unlock_new_inode(inode);
goto out;
}
/* Inspired by filemap_check_errors() */
int btrfs_inode_check_errors(struct inode *inode)
{
int ret = 0;
if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
ret = -ENOSPC;
if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
ret = -EIO;
return ret;
}
static const struct inode_operations btrfs_dir_inode_operations = {
.getattr = btrfs_getattr,
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.link = btrfs_link,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
.rename2 = btrfs_rename2,
.symlink = btrfs_symlink,
.setattr = btrfs_setattr,
.mknod = btrfs_mknod,
.setxattr = btrfs_setxattr,
.getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
.tmpfile = btrfs_tmpfile,
};
static const struct inode_operations btrfs_dir_ro_inode_operations = {
.lookup = btrfs_lookup,
.permission = btrfs_permission,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate = btrfs_real_readdir,
.unlocked_ioctl = btrfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = btrfs_ioctl,
#endif
.release = btrfs_release_file,
.fsync = btrfs_sync_file,
};
static const struct extent_io_ops btrfs_extent_io_ops = {
.fill_delalloc = run_delalloc_range,
.submit_bio_hook = btrfs_submit_bio_hook,
.merge_bio_hook = btrfs_merge_bio_hook,
.readpage_end_io_hook = btrfs_readpage_end_io_hook,
.writepage_end_io_hook = btrfs_writepage_end_io_hook,
.writepage_start_hook = btrfs_writepage_start_hook,
.set_bit_hook = btrfs_set_bit_hook,
.clear_bit_hook = btrfs_clear_bit_hook,
.merge_extent_hook = btrfs_merge_extent_hook,
.split_extent_hook = btrfs_split_extent_hook,
};
/*
* btrfs doesn't support the bmap operation because swapfiles
* use bmap to make a mapping of extents in the file. They assume
* these extents won't change over the life of the file and they
* use the bmap result to do IO directly to the drive.
*
* the btrfs bmap call would return logical addresses that aren't
* suitable for IO and they also will change frequently as COW
* operations happen. So, swapfile + btrfs == corruption.
*
* For now we're avoiding this by dropping bmap.
*/
static const struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.writepages = btrfs_writepages,
.readpages = btrfs_readpages,
.direct_IO = btrfs_direct_IO,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
.set_page_dirty = btrfs_set_page_dirty,
.error_remove_page = generic_error_remove_page,
};
static const struct address_space_operations btrfs_symlink_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
};
static const struct inode_operations btrfs_file_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.setxattr = btrfs_setxattr,
.getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
.fiemap = btrfs_fiemap,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.setxattr = btrfs_setxattr,
.getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct inode_operations btrfs_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = page_get_link,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.setxattr = btrfs_setxattr,
.getxattr = generic_getxattr,
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.update_time = btrfs_update_time,
};
const struct dentry_operations btrfs_dentry_operations = {
.d_delete = btrfs_dentry_delete,
.d_release = btrfs_dentry_release,
};
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