xfs: return a failure address from xfs_rmap_irec_offset_unpack

Currently, xfs_rmap_irec_offset_unpack returns only 0 or -EFSCORRUPTED.
Change this function to return the code address of a failed conversion
in preparation for the next patch, which standardizes localized record
checking and reporting code.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/libxfs/xfs_rmap.c

@@ -193,7 +193,7 @@ xfs_rmap_delete(
 }
 
 /* Convert an internal btree record to an rmap record. */
-int
+xfs_failaddr_t
 xfs_rmap_btrec_to_irec(
 	const union xfs_btree_rec	*rec,
 	struct xfs_rmap_irec		*irec)
@@ -2320,11 +2320,10 @@ xfs_rmap_query_range_helper(
 {
 	struct xfs_rmap_query_range_info	*query = priv;
 	struct xfs_rmap_irec			irec;
-	int					error;
 
-	error = xfs_rmap_btrec_to_irec(rec, &irec);
-	if (error)
-		return error;
+	if (xfs_rmap_btrec_to_irec(rec, &irec) != NULL)
+		return -EFSCORRUPTED;
+
 	return query->fn(cur, &irec, query->priv);
 }
 

fs/xfs/libxfs/xfs_rmap.h

@@ -62,13 +62,14 @@ xfs_rmap_irec_offset_pack(
 	return x;
 }
 
-static inline int
+static inline xfs_failaddr_t
 xfs_rmap_irec_offset_unpack(
 	__u64			offset,
 	struct xfs_rmap_irec	*irec)
 {
 	if (offset & ~(XFS_RMAP_OFF_MASK | XFS_RMAP_OFF_FLAGS))
-		return -EFSCORRUPTED;
+		return __this_address;
+
 	irec->rm_offset = XFS_RMAP_OFF(offset);
 	irec->rm_flags = 0;
 	if (offset & XFS_RMAP_OFF_ATTR_FORK)
@@ -77,7 +78,7 @@ xfs_rmap_irec_offset_unpack(
 		irec->rm_flags |= XFS_RMAP_BMBT_BLOCK;
 	if (offset & XFS_RMAP_OFF_UNWRITTEN)
 		irec->rm_flags |= XFS_RMAP_UNWRITTEN;
-	return 0;
+	return NULL;
 }
 
 static inline void
@@ -192,7 +193,7 @@ int xfs_rmap_lookup_le_range(struct xfs_btree_cur *cur, xfs_agblock_t bno,
 int xfs_rmap_compare(const struct xfs_rmap_irec *a,
 		const struct xfs_rmap_irec *b);
 union xfs_btree_rec;
-int xfs_rmap_btrec_to_irec(const union xfs_btree_rec *rec,
+xfs_failaddr_t xfs_rmap_btrec_to_irec(const union xfs_btree_rec *rec,
 		struct xfs_rmap_irec *irec);
 int xfs_rmap_has_record(struct xfs_btree_cur *cur, xfs_agblock_t bno,
 		xfs_extlen_t len, bool *exists);

fs/xfs/scrub/rmap.c

@@ -100,11 +100,11 @@ xchk_rmapbt_rec(
 	bool			is_unwritten;
 	bool			is_bmbt;
 	bool			is_attr;
-	int			error;
 
-	error = xfs_rmap_btrec_to_irec(rec, &irec);
-	if (!xchk_btree_process_error(bs->sc, bs->cur, 0, &error))
-		goto out;
+	if (xfs_rmap_btrec_to_irec(rec, &irec) != NULL) {
+		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+		return 0;
+	}
 
 	/* Check extent. */
 	if (irec.rm_startblock + irec.rm_blockcount <= irec.rm_startblock)
@@ -159,8 +159,7 @@ xchk_rmapbt_rec(
 	}
 
 	xchk_rmapbt_xref(bs->sc, &irec);
-out:
-	return error;
+	return 0;
 }
 
 /* Scrub the rmap btree for some AG. */