xfs: hoist recovered refcount intent checks out of xfs_cui_item_recover

When we recover a refcount 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_refcount_item.c

@@ -417,6 +417,38 @@ const struct xfs_defer_op_type xfs_refcount_update_defer_type = {
 	.cancel_item	= xfs_refcount_update_cancel_item,
 };
 
+/* Is this recovered CUI ok? */
+static inline bool
+xfs_cui_validate_phys(
+	struct xfs_mount		*mp,
+	struct xfs_phys_extent		*refc)
+{
+	xfs_fsblock_t			startblock_fsb;
+	bool				op_ok;
+
+	startblock_fsb = XFS_BB_TO_FSB(mp,
+			   XFS_FSB_TO_DADDR(mp, refc->pe_startblock));
+	switch (refc->pe_flags & XFS_REFCOUNT_EXTENT_TYPE_MASK) {
+	case XFS_REFCOUNT_INCREASE:
+	case XFS_REFCOUNT_DECREASE:
+	case XFS_REFCOUNT_ALLOC_COW:
+	case XFS_REFCOUNT_FREE_COW:
+		op_ok = true;
+		break;
+	default:
+		op_ok = false;
+		break;
+	}
+	if (!op_ok || startblock_fsb == 0 ||
+	    refc->pe_len == 0 ||
+	    startblock_fsb >= mp->m_sb.sb_dblocks ||
+	    refc->pe_len >= mp->m_sb.sb_agblocks ||
+	    (refc->pe_flags & ~XFS_REFCOUNT_EXTENT_FLAGS))
+		return false;
+
+	return true;
+}
+
 /*
  * Process a refcount update intent item that was recovered from the log.
  * We need to update the refcountbt.
@@ -433,11 +465,9 @@ xfs_cui_item_recover(
 	struct xfs_trans		*tp;
 	struct xfs_btree_cur		*rcur = NULL;
 	struct xfs_mount		*mp = lip->li_mountp;
-	xfs_fsblock_t			startblock_fsb;
 	xfs_fsblock_t			new_fsb;
 	xfs_extlen_t			new_len;
 	unsigned int			refc_type;
-	bool				op_ok;
 	bool				requeue_only = false;
 	enum xfs_refcount_intent_type	type;
 	int				i;
@@ -449,26 +479,13 @@ xfs_cui_item_recover(
 	 * just toss the CUI.
 	 */
 	for (i = 0; i < cuip->cui_format.cui_nextents; i++) {
-		refc = &cuip->cui_format.cui_extents[i];
-		startblock_fsb = XFS_BB_TO_FSB(mp,
-				   XFS_FSB_TO_DADDR(mp, refc->pe_startblock));
-		switch (refc->pe_flags & XFS_REFCOUNT_EXTENT_TYPE_MASK) {
-		case XFS_REFCOUNT_INCREASE:
-		case XFS_REFCOUNT_DECREASE:
-		case XFS_REFCOUNT_ALLOC_COW:
-		case XFS_REFCOUNT_FREE_COW:
-			op_ok = true;
-			break;
-		default:
-			op_ok = false;
-			break;
-		}
-		if (!op_ok || startblock_fsb == 0 ||
-		    refc->pe_len == 0 ||
-		    startblock_fsb >= mp->m_sb.sb_dblocks ||
-		    refc->pe_len >= mp->m_sb.sb_agblocks ||
-		    (refc->pe_flags & ~XFS_REFCOUNT_EXTENT_FLAGS))
+		if (!xfs_cui_validate_phys(mp,
+					&cuip->cui_format.cui_extents[i])) {
+			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+					&cuip->cui_format,
+					sizeof(cuip->cui_format));
 			return -EFSCORRUPTED;
+		}
 	}
 
 	/*