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f2fs: synchronize atomic write aborts

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To fix a race condition between atomic write aborts, I use the inode
lock and make COW inode to be re-usable thoroughout the whole
atomic file inode lifetime.

Reported-by: syzbot+823000d23b3400619f7c@syzkaller.appspotmail.com
Fixes: 3db1de0e58 ("f2fs: change the current atomic write way")
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Daeho Jeong 2023-02-09 10:18:19 -08:00 committed by Jaegeuk Kim
parent 7e986855fe
commit a46bebd502
4 changed files with 38 additions and 22 deletions
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44
fs/f2fs/file.c
View File

@ -1863,7 +1863,10 @@ static int f2fs_release_file(struct inode *inode, struct file *filp)
atomic_read(&inode->i_writecount) != 1)
return 0;
inode_lock(inode);
f2fs_abort_atomic_write(inode, true);
inode_unlock(inode);
return 0;
}
@ -1878,8 +1881,12 @@ static int f2fs_file_flush(struct file *file, fl_owner_t id)
* before dropping file lock, it needs to do in ->flush.
*/
if (F2FS_I(inode)->atomic_write_task == current &&
(current->flags & PF_EXITING))
(current->flags & PF_EXITING)) {
inode_lock(inode);
f2fs_abort_atomic_write(inode, true);
inode_unlock(inode);
}
return 0;
}
@ -2085,19 +2092,28 @@ static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate)
goto out;
}
/* Create a COW inode for atomic write */
pinode = f2fs_iget(inode->i_sb, fi->i_pino);
if (IS_ERR(pinode)) {
f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
ret = PTR_ERR(pinode);
goto out;
}
/* Check if the inode already has a COW inode */
if (fi->cow_inode == NULL) {
/* Create a COW inode for atomic write */
pinode = f2fs_iget(inode->i_sb, fi->i_pino);
if (IS_ERR(pinode)) {
f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
ret = PTR_ERR(pinode);
goto out;
}
ret = f2fs_get_tmpfile(mnt_userns, pinode, &fi->cow_inode);
iput(pinode);
if (ret) {
f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
goto out;
ret = f2fs_get_tmpfile(mnt_userns, pinode, &fi->cow_inode);
iput(pinode);
if (ret) {
f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
goto out;
}
set_inode_flag(fi->cow_inode, FI_COW_FILE);
clear_inode_flag(fi->cow_inode, FI_INLINE_DATA);
} else {
/* Reuse the already created COW inode */
f2fs_do_truncate_blocks(fi->cow_inode, 0, true);
}
f2fs_write_inode(inode, NULL);
@ -2105,8 +2121,6 @@ static int f2fs_ioc_start_atomic_write(struct file *filp, bool truncate)
stat_inc_atomic_inode(inode);
set_inode_flag(inode, FI_ATOMIC_FILE);
set_inode_flag(fi->cow_inode, FI_COW_FILE);
clear_inode_flag(fi->cow_inode, FI_INLINE_DATA);
isize = i_size_read(inode);
fi->original_i_size = isize;

11
fs/f2fs/inode.c
View File

@ -767,11 +767,18 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
void f2fs_evict_inode(struct inode *inode)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
nid_t xnid = F2FS_I(inode)->i_xattr_nid;
struct f2fs_inode_info *fi = F2FS_I(inode);
nid_t xnid = fi->i_xattr_nid;
int err = 0;
f2fs_abort_atomic_write(inode, true);
if (fi->cow_inode) {
clear_inode_flag(fi->cow_inode, FI_COW_FILE);
iput(fi->cow_inode);
fi->cow_inode = NULL;
}
trace_f2fs_evict_inode(inode);
truncate_inode_pages_final(&inode->i_data);
@ -856,7 +863,7 @@ no_delete:
stat_dec_inline_inode(inode);
stat_dec_compr_inode(inode);
stat_sub_compr_blocks(inode,
atomic_read(&F2FS_I(inode)->i_compr_blocks));
atomic_read(&fi->i_compr_blocks));
if (likely(!f2fs_cp_error(sbi) &&
!is_sbi_flag_set(sbi, SBI_CP_DISABLED)))

3
fs/f2fs/segment.c
View File

@ -192,9 +192,6 @@ void f2fs_abort_atomic_write(struct inode *inode, bool clean)
if (!f2fs_is_atomic_file(inode))
return;
clear_inode_flag(fi->cow_inode, FI_COW_FILE);
iput(fi->cow_inode);
fi->cow_inode = NULL;
release_atomic_write_cnt(inode);
clear_inode_flag(inode, FI_ATOMIC_COMMITTED);
clear_inode_flag(inode, FI_ATOMIC_REPLACE);

2
fs/f2fs/super.c
View File

@ -1427,8 +1427,6 @@ static int f2fs_drop_inode(struct inode *inode)
atomic_inc(&inode->i_count);
spin_unlock(&inode->i_lock);
f2fs_abort_atomic_write(inode, true);
/* should remain fi->extent_tree for writepage */
f2fs_destroy_extent_node(inode);