Commits
Sergei Trofimovich committed 800ee2247f4
btrfs: fix crash in remount(thread_pool=) case Reproducer: mount /dev/ubda /mnt mount -oremount,thread_pool=42 /mnt Gives a crash: ? btrfs_workqueue_set_max+0x0/0x70 btrfs_resize_thread_pool+0xe3/0xf0 ? sync_filesystem+0x0/0xc0 ? btrfs_resize_thread_pool+0x0/0xf0 btrfs_remount+0x1d2/0x570 ? kern_path+0x0/0x80 do_remount_sb+0xd9/0x1c0 do_mount+0x26a/0xbf0 ? kfree+0x0/0x1b0 SyS_mount+0xc4/0x110 It's a call btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers, new_pool_size); with fs_info->scrub_wr_completion_workers = NULL; as scrub wqs get created only on user's demand. Patch skips not-created-yet workqueues. Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> CC: Qu Wenruo <quwenruo@cn.fujitsu.com> CC: Chris Mason <clm@fb.com> CC: Josef Bacik <jbacik@fb.com> CC: linux-btrfs@vger.kernel.org Signed-off-by: Chris Mason <clm@fb.com>