Commit e4e7ede7 authored Jun 27, 2018 by Filipe Manana Committed by David Sterba Jun 28, 2018

Btrfs: fix mount failure when qgroup rescan is in progress



If a power failure happens while the qgroup rescan kthread is running,
the next mount operation will always fail. This is because of a recent
regression that makes qgroup_rescan_init() incorrectly return -EINVAL
when we are mounting the filesystem (through btrfs_read_qgroup_config()).
This causes the -EINVAL error to be returned regardless of any qgroup
flags being set instead of returning the error only when neither of
the flags BTRFS_QGROUP_STATUS_FLAG_RESCAN nor BTRFS_QGROUP_STATUS_FLAG_ON
are set.

A test case for fstests follows up soon.

Fixes: 9593bf49 ("btrfs: qgroup: show more meaningful qgroup_rescan_init error message")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

parent 717beb96

fs/btrfs/qgroup.c

+10 −3

Original line number	Diff line number	Diff line
		@@ -2786,13 +2786,20 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,

		if (!init_flags) {
		/* we're resuming qgroup rescan at mount time */
		if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN))
		if (!(fs_info->qgroup_flags &
		BTRFS_QGROUP_STATUS_FLAG_RESCAN)) {
		btrfs_warn(fs_info,
		"qgroup rescan init failed, qgroup is not enabled");
		else if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
		ret = -EINVAL;
		} else if (!(fs_info->qgroup_flags &
		BTRFS_QGROUP_STATUS_FLAG_ON)) {
		btrfs_warn(fs_info,
		"qgroup rescan init failed, qgroup rescan is not queued");
		return -EINVAL;
		ret = -EINVAL;
		}

		if (ret)
		return ret;
		}

		mutex_lock(&fs_info->qgroup_rescan_lock);

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