xfs: hoist recovered rmap intent checks out of xfs_rui_item_recover

When we recover a rmap intent from the log, we need to validate its
contents before we try to replay them.  Hoist the checking code into a
separate function in preparation to refactor this code to use validation
helpers.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/xfs_rmap_item.c

@@ -460,6 +460,42 @@ const struct xfs_defer_op_type xfs_rmap_update_defer_type = {
 	.cancel_item	= xfs_rmap_update_cancel_item,
 };
 
+/* Is this recovered RUI ok? */
+static inline bool
+xfs_rui_validate_map(
+	struct xfs_mount		*mp,
+	struct xfs_map_extent		*rmap)
+{
+	xfs_fsblock_t			startblock_fsb;
+	bool				op_ok;
+
+	startblock_fsb = XFS_BB_TO_FSB(mp,
+			   XFS_FSB_TO_DADDR(mp, rmap->me_startblock));
+	switch (rmap->me_flags & XFS_RMAP_EXTENT_TYPE_MASK) {
+	case XFS_RMAP_EXTENT_MAP:
+	case XFS_RMAP_EXTENT_MAP_SHARED:
+	case XFS_RMAP_EXTENT_UNMAP:
+	case XFS_RMAP_EXTENT_UNMAP_SHARED:
+	case XFS_RMAP_EXTENT_CONVERT:
+	case XFS_RMAP_EXTENT_CONVERT_SHARED:
+	case XFS_RMAP_EXTENT_ALLOC:
+	case XFS_RMAP_EXTENT_FREE:
+		op_ok = true;
+		break;
+	default:
+		op_ok = false;
+		break;
+	}
+	if (!op_ok || startblock_fsb == 0 ||
+	    rmap->me_len == 0 ||
+	    startblock_fsb >= mp->m_sb.sb_dblocks ||
+	    rmap->me_len >= mp->m_sb.sb_agblocks ||
+	    (rmap->me_flags & ~XFS_RMAP_EXTENT_FLAGS))
+		return false;
+
+	return true;
+}
+
 /*
  * Process an rmap update intent item that was recovered from the log.
  * We need to update the rmapbt.
@@ -475,10 +511,8 @@ xfs_rui_item_recover(
 	struct xfs_trans		*tp;
 	struct xfs_btree_cur		*rcur = NULL;
 	struct xfs_mount		*mp = lip->li_mountp;
-	xfs_fsblock_t			startblock_fsb;
 	enum xfs_rmap_intent_type	type;
 	xfs_exntst_t			state;
-	bool				op_ok;
 	int				i;
 	int				whichfork;
 	int				error = 0;
@@ -489,30 +523,13 @@ xfs_rui_item_recover(
 	 * just toss the RUI.
 	 */
 	for (i = 0; i < ruip->rui_format.rui_nextents; i++) {
-		rmap = &ruip->rui_format.rui_extents[i];
-		startblock_fsb = XFS_BB_TO_FSB(mp,
-				   XFS_FSB_TO_DADDR(mp, rmap->me_startblock));
-		switch (rmap->me_flags & XFS_RMAP_EXTENT_TYPE_MASK) {
-		case XFS_RMAP_EXTENT_MAP:
-		case XFS_RMAP_EXTENT_MAP_SHARED:
-		case XFS_RMAP_EXTENT_UNMAP:
-		case XFS_RMAP_EXTENT_UNMAP_SHARED:
-		case XFS_RMAP_EXTENT_CONVERT:
-		case XFS_RMAP_EXTENT_CONVERT_SHARED:
-		case XFS_RMAP_EXTENT_ALLOC:
-		case XFS_RMAP_EXTENT_FREE:
-			op_ok = true;
-			break;
-		default:
-			op_ok = false;
-			break;
-		}
-		if (!op_ok || startblock_fsb == 0 ||
-		    rmap->me_len == 0 ||
-		    startblock_fsb >= mp->m_sb.sb_dblocks ||
-		    rmap->me_len >= mp->m_sb.sb_agblocks ||
-		    (rmap->me_flags & ~XFS_RMAP_EXTENT_FLAGS))
+		if (!xfs_rui_validate_map(mp,
+					&ruip->rui_format.rui_extents[i])) {
+			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+					&ruip->rui_format,
+					sizeof(ruip->rui_format));
 			return -EFSCORRUPTED;
+		}
 	}
 
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,