xfs: refactor long-format btree header verification routines

Create two helper functions to verify the headers of a long format
btree block.  We'll use this later for the realtime rmapbt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 54c0a927a0fa..95d4c355c466 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -4529,6 +4529,51 @@ xfs_btree_change_owner(
 			&bbcoi);
 }
 
+/* Verify the v5 fields of a long-format btree block. */
+bool
+xfs_btree_lblock_v5hdr_verify(
+	struct xfs_buf		*bp,
+	uint64_t		owner)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return false;
+	if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
+		return false;
+	if (block->bb_u.l.bb_blkno != cpu_to_be64(bp->b_bn))
+		return false;
+	if (owner != XFS_RMAP_OWN_UNKNOWN &&
+	    be64_to_cpu(block->bb_u.l.bb_owner) != owner)
+		return false;
+	return true;
+}
+
+/* Verify a long-format btree block. */
+bool
+xfs_btree_lblock_verify(
+	struct xfs_buf		*bp,
+	unsigned int		max_recs)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+
+	/* numrecs verification */
+	if (be16_to_cpu(block->bb_numrecs) > max_recs)
+		return false;
+
+	/* sibling pointer verification */
+	if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
+	    !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_leftsib)))
+		return false;
+	if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
+	    !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_rightsib)))
+		return false;
+
+	return true;
+}
+
 /**
  * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
  *				      btree block