From: Chao Yu yuchao0@huawei.com
[ 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 --- fs/f2fs/namei.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index 8617e742d087..e20a0f9e6845 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -772,7 +772,11 @@ 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); @@ -966,7 +970,11 @@ 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); }