Commit a690e5f2 authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba
Browse files

btrfs: mark resumed async balance as writing 



When btrfs balance is interrupted with umount, the background balance
resumes on the next mount. There is a potential deadlock with FS freezing
here like as described in commit 26559780b953 ("btrfs: zoned: mark
relocation as writing"). Mark the process as sb_writing to avoid it.

Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent d03ae0d3

fs/btrfs/volumes.c

+2 −0
Original line number Diff line number Diff line
@@ -4430,10 +4430,12 @@ static int balance_kthread(void *data) 
	struct btrfs_fs_info *fs_info = data;

	int ret = 0;



	sb_start_write(fs_info->sb);

	mutex_lock(&fs_info->balance_mutex);

	if (fs_info->balance_ctl)

		ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL);

	mutex_unlock(&fs_info->balance_mutex);

	sb_end_write(fs_info->sb);



	return ret;

}