If we do a direct IO sync write, at btrfs_sync_file(), and we need to skip inode logging or we get an error starting a transaction or an error when flushing delalloc, we end up unlocking the inode when we shouldn't under the 'out_release_extents' label, and then unlock it again at btrfs_direct_write(). Fix that by checking if we have to skip inode unlocking under that label. Reported-by: syzbot+7dbbb74af6291b5a5a8b@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://lore.kernel.org/linux-btrfs/000000000000dfd631061eaeb4bc@xxxxxxxxxx/ Fixes: 939b656bc8ab ("btrfs: fix corruption after buffer fault in during direct IO append write") Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 9f10a9f23fcc..9914419f3b7d 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1868,7 +1868,10 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) out_release_extents: btrfs_release_log_ctx_extents(&ctx); - btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP); + if (skip_ilock) + up_write(&inode->i_mmap_lock); + else + btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP); goto out; }
