On 2018/4/19 6:48, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> xfstest generic/429 sometimes hangs on f2fs, caused by a thread being
> unable to take a directory's i_rwsem for write in vfs_rmdir(). In the
> test, one thread repeatedly creates and removes a directory, and other
> threads repeatedly look up a file in the directory. The bug is that
> f2fs_mkdir() calls d_instantiate() before unlock_new_inode(), resulting
> in the directory inode being exposed to lookups before it has been fully
> initialized. And with CONFIG_DEBUG_LOCK_ALLOC, unlock_new_inode()
> reinitializes ->i_rwsem, corrupting its state when it is already held.
>
> Fix it by calling unlock_new_inode() before d_instantiate(). This
> matches what other filesystems do.
>
> Fixes: 57397d86c62d ("f2fs: add inode operations for special inodes")
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>
Thanks,
