diff options
| author | Chao Yu <yuchao0@huawei.com> | 2021-01-12 09:55:09 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-07 12:20:46 +0100 |
| commit | 8253cc11abb2baae408a2ac40e88c7910d1eb549 (patch) | |
| tree | 431f8d7a26aaaecd9335ffcb76561c772167f5a3 | |
| parent | 77dc257b4feb05c9e92d57d2021428a4f38a19e4 (diff) | |
f2fs: fix to set/clear I_LINKABLE under i_lock
[ Upstream commit 46085f37fc9e12d5c3539fb768b5ad7951e72acf ]
fsstress + fault injection test case reports a warning message as
below:
WARNING: CPU: 13 PID: 6226 at fs/inode.c:361 inc_nlink+0x32/0x40
Call Trace:
f2fs_init_inode_metadata+0x25c/0x4a0 [f2fs]
f2fs_add_inline_entry+0x153/0x3b0 [f2fs]
f2fs_add_dentry+0x75/0x80 [f2fs]
f2fs_do_add_link+0x108/0x160 [f2fs]
f2fs_rename2+0x6ab/0x14f0 [f2fs]
vfs_rename+0x70c/0x940
do_renameat2+0x4d8/0x4f0
__x64_sys_renameat2+0x4b/0x60
do_syscall_64+0x33/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Following race case can cause this:
Thread A Kworker
- f2fs_rename
- f2fs_create_whiteout
- __f2fs_tmpfile
- f2fs_i_links_write
- f2fs_mark_inode_dirty_sync
- mark_inode_dirty_sync
- writeback_single_inode
- __writeback_single_inode
- spin_lock(&inode->i_lock)
- inode->i_state |= I_LINKABLE
- inode->i_state &= ~dirty
- spin_unlock(&inode->i_lock)
- f2fs_add_link
- f2fs_do_add_link
- f2fs_add_dentry
- f2fs_add_inline_entry
- f2fs_init_inode_metadata
- f2fs_i_links_write
- inc_nlink
- WARN_ON(!(inode->i_state & I_LINKABLE))
Fix to add i_lock to avoid i_state update race condition.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/f2fs/namei.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index 5d9584281935..3a97ac56821b 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -797,7 +797,11 @@ static int __f2fs_tmpfile(struct inode *dir, struct dentry *dentry, if (whiteout) { f2fs_i_links_write(inode, false); + + spin_lock(&inode->i_lock); inode->i_state |= I_LINKABLE; + spin_unlock(&inode->i_lock); + *whiteout = inode; } else { d_tmpfile(dentry, inode); @@ -996,7 +1000,11 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry, err = f2fs_add_link(old_dentry, whiteout); if (err) goto put_out_dir; + + spin_lock(&whiteout->i_lock); whiteout->i_state &= ~I_LINKABLE; + spin_unlock(&whiteout->i_lock); + iput(whiteout); } |