xfs: refactor bmap record validation

Refactor the bmap validator into a more complete helper that looks for
extents that run off the end of the device, overflow into the next AG,
or have invalid flag states.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/libxfs/xfs_bmap.c

@@ -1261,11 +1261,15 @@ xfs_iread_extents(
 		 */
 		frp = XFS_BMBT_REC_ADDR(mp, block, 1);
 		for (j = 0; j < num_recs; j++, frp++, i++) {
+			xfs_failaddr_t	fa;
+
 			xfs_bmbt_disk_get_all(frp, &new);
-			if (!xfs_bmbt_validate_extent(mp, whichfork, &new)) {
-				XFS_ERROR_REPORT("xfs_bmap_read_extents(2)",
-						 XFS_ERRLEVEL_LOW, mp);
+			fa = xfs_bmap_validate_extent(ip, whichfork, &new);
+			if (fa) {
 				error = -EFSCORRUPTED;
+				xfs_inode_verifier_error(ip, error,
+						"xfs_iread_extents(2)",
+						frp, sizeof(*frp), fa);
 				goto out_brelse;
 			}
 			xfs_iext_insert(ip, &icur, &new, state);
@@ -6154,3 +6158,39 @@ xfs_bmap_finish_one(
 
 	return error;
 }
+
+/* Check that an inode's extent does not have invalid flags or bad ranges. */
+xfs_failaddr_t
+xfs_bmap_validate_extent(
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_bmbt_irec	*irec)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	xfs_fsblock_t		endfsb;
+	bool			isrt;
+
+	isrt = XFS_IS_REALTIME_INODE(ip);
+	endfsb = irec->br_startblock + irec->br_blockcount - 1;
+	if (isrt) {
+		if (!xfs_verify_rtbno(mp, irec->br_startblock))
+			return __this_address;
+		if (!xfs_verify_rtbno(mp, endfsb))
+			return __this_address;
+	} else {
+		if (!xfs_verify_fsbno(mp, irec->br_startblock))
+			return __this_address;
+		if (!xfs_verify_fsbno(mp, endfsb))
+			return __this_address;
+		if (XFS_FSB_TO_AGNO(mp, irec->br_startblock) !=
+		    XFS_FSB_TO_AGNO(mp, endfsb))
+			return __this_address;
+	}
+	if (irec->br_state != XFS_EXT_NORM) {
+		if (whichfork != XFS_DATA_FORK)
+			return __this_address;
+		if (!xfs_sb_version_hasextflgbit(&mp->m_sb))
+			return __this_address;
+	}
+	return NULL;
+}

fs/xfs/libxfs/xfs_bmap.h

@@ -274,4 +274,7 @@ static inline int xfs_bmap_fork_to_state(int whichfork)
 	}
 }
 
+xfs_failaddr_t xfs_bmap_validate_extent(struct xfs_inode *ip, int whichfork,
+		struct xfs_bmbt_irec *irec);
+
 #endif	/* __XFS_BMAP_H__ */

fs/xfs/libxfs/xfs_bmap_btree.h

@@ -118,18 +118,4 @@ extern int xfs_bmbt_change_owner(struct xfs_trans *tp, struct xfs_inode *ip,
 extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *,
 		struct xfs_trans *, struct xfs_inode *, int);
 
-/*
- * Check that the extent does not contain an invalid unwritten extent flag.
- */
-static inline bool xfs_bmbt_validate_extent(struct xfs_mount *mp, int whichfork,
-		struct xfs_bmbt_irec *irec)
-{
-	if (irec->br_state == XFS_EXT_NORM)
-		return true;
-	if (whichfork == XFS_DATA_FORK &&
-	    xfs_sb_version_hasextflgbit(&mp->m_sb))
-		return true;
-	return false;
-}
-
 #endif	/* __XFS_BMAP_BTREE_H__ */

fs/xfs/libxfs/xfs_inode_fork.c

@@ -245,10 +245,14 @@ xfs_iformat_extents(
 
 		xfs_iext_first(ifp, &icur);
 		for (i = 0; i < nex; i++, dp++) {
+			xfs_failaddr_t	fa;
+
 			xfs_bmbt_disk_get_all(dp, &new);
-			if (!xfs_bmbt_validate_extent(mp, whichfork, &new)) {
-				XFS_ERROR_REPORT("xfs_iformat_extents(2)",
-						 XFS_ERRLEVEL_LOW, mp);
+			fa = xfs_bmap_validate_extent(ip, whichfork, &new);
+			if (fa) {
+				xfs_inode_verifier_error(ip, -EFSCORRUPTED,
+						"xfs_iformat_extents(2)",
+						dp, sizeof(*dp), fa);
 				return -EFSCORRUPTED;
 			}
 
@@ -595,7 +599,7 @@ xfs_iextents_copy(
 	for_each_xfs_iext(ifp, &icur, &rec) {
 		if (isnullstartblock(rec.br_startblock))
 			continue;
-		ASSERT(xfs_bmbt_validate_extent(ip->i_mount, whichfork, &rec));
+		ASSERT(xfs_bmap_validate_extent(ip, whichfork, &rec) == NULL);
 		xfs_bmbt_disk_set_all(dp, &rec);
 		trace_xfs_write_extent(ip, &icur, state, _RET_IP_);
 		copied += sizeof(struct xfs_bmbt_rec);