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Commit fcfbe2c4 authored by Dave Chinner's avatar Dave Chinner Committed by Dave Chinner
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xfs: log recovery needs to validate against sb_meta_uuid 



Now that sb_uuid can be changed by the user, we cannot use this to
validate the metadata blocks being recovered belong to this
filesystem. We must check against the sb_meta_uuid as that will
remain unchanged.

There is a complication in this code - the superblock itself. We can
not check the sb_meta_uuid unconditionally, as that may not be set
on disk. Hence we must verify the superblock sb_uuid matches between
the log record and the in-core superblock.

Found by inspection after the previous two problems were found.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent ac383de2

fs/xfs/xfs_log_recover.c

+12 −2
Original line number Diff line number Diff line
@@ -1890,7 +1890,17 @@ xlog_recover_get_buf_lsn( 
		uuid = &((struct xfs_attr3_rmt_hdr *)blk)->rm_uuid;

		break;

	case XFS_SB_MAGIC:

		/*

		 * superblock uuids are magic. We may or may not have a

		 * sb_meta_uuid on disk, but it will be set in the in-core

		 * superblock. We set the uuid pointer for verification

		 * according to the superblock feature mask to ensure we check

		 * the relevant UUID in the superblock.

		 */

		lsn = be64_to_cpu(((struct xfs_dsb *)blk)->sb_lsn);

		if (xfs_sb_version_hasmetauuid(&mp->m_sb))

			uuid = &((struct xfs_dsb *)blk)->sb_meta_uuid;

		else

			uuid = &((struct xfs_dsb *)blk)->sb_uuid;

		break;

	default:
@@ -1898,7 +1908,7 @@ xlog_recover_get_buf_lsn( 
	}



	if (lsn != (xfs_lsn_t)-1) {

		if (!uuid_equal(&mp->m_sb.sb_uuid, uuid))

		if (!uuid_equal(&mp->m_sb.sb_meta_uuid, uuid))

			goto recover_immediately;

		return lsn;

	}