[PATCH 5.10 04/21] xfs: improve the code that checks recovered rmap intent items

[Siddh Raman Pant]

From: "Darrick J. Wong" <darrick.wong@xxxxxxxxxx>

The code that validates recovered rmap intent items is kind of a mess --
it doesn't use the standard xfs type validators, and it doesn't check
for things that it should.  Fix the validator function to use the
standard validation helpers and look for more types of obvious errors.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
(cherry picked from commit c447ad62dc906f4b5f788e8ff20c1768ab2eab2c)
Stable-dep-of: 7b5f775be14a ("xfs: fix unmount hang with unflushable inodes stuck in the AIL")
Signed-off-by: Siddh Raman Pant <siddh.raman.pant@xxxxxxxxxx>
---
 fs/xfs/xfs_rmap_item.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/fs/xfs/xfs_rmap_item.c b/fs/xfs/xfs_rmap_item.c
index 31cfd734962f..f248e2b0ab5d 100644
--- a/fs/xfs/xfs_rmap_item.c
+++ b/fs/xfs/xfs_rmap_item.c
@@ -466,11 +466,9 @@ xfs_rui_validate_map(
 	struct xfs_mount		*mp,
 	struct xfs_map_extent		*rmap)
 {
-	xfs_fsblock_t			startblock_fsb;
-	bool				op_ok;
+	if (rmap->me_flags & ~XFS_RMAP_EXTENT_FLAGS)
+		return false;
 
-	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:
@@ -480,17 +478,25 @@ xfs_rui_validate_map(
 	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;
+		return false;
 	}
-	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_RMAP_NON_INODE_OWNER(rmap->me_owner) &&
+	    !xfs_verify_ino(mp, rmap->me_owner))
+		return false;
+
+	if (rmap->me_startoff + rmap->me_len <= rmap->me_startoff)
+		return false;
+
+	if (rmap->me_startblock + rmap->me_len <= rmap->me_startblock)
+		return false;
+
+	if (!xfs_verify_fsbno(mp, rmap->me_startblock))
+		return false;
+
+	if (!xfs_verify_fsbno(mp, rmap->me_startblock + rmap->me_len - 1))
 		return false;
 
 	return true;
-- 
2.53.0