Commit 05c49e6b authored Nov 11, 2018 by Anand Jain Committed by David Sterba Dec 17, 2018

btrfs: dev-replace: go back to suspend state if another EXCL_OP is running



In a secnario where balance and replace co-exists as below,

  - start balance
  - pause balance
  - start replace
  - reboot

and when system restarts, balance resumes first. Then the replace is
attempted to restart but will fail as the EXCL_OP lock is already held
by the balance. If so place the replace state back to
BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED state.

Fixes: 010a47bd ("btrfs: add proper safety check before resuming dev-replace")
CC: stable@vger.kernel.org # 4.18+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 0d228ece

fs/btrfs/dev-replace.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -903,6 +903,10 @@ int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info)
		* dev-replace to start anyway.
		*/
		if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
		btrfs_dev_replace_write_lock(dev_replace);
		dev_replace->replace_state =
		BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED;
		btrfs_dev_replace_write_unlock(dev_replace);
		btrfs_info(fs_info,
		"cannot resume dev-replace, other exclusive operation running");
		return 0;