xfs: improve the code that checks recovered refcount intent items

The code that validates recovered refcount 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.

Note that we can't actually check the startblock until we know if the
refcount item is targetting the realtime device, so that has to be
separate.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

1 files changed, 12 insertions, 12 deletions

diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c
index 13bfebc9dbb0..32f405d85825 100644
--- a/fs/xfs/xfs_refcount_item.c
+++ b/fs/xfs/xfs_refcount_item.c
@@ -423,27 +423,27 @@ xfs_cui_validate_phys(
 	struct xfs_mount		*mp,
 	struct xfs_phys_extent		*refc)
 {
-	xfs_fsblock_t			startblock_fsb;
-	bool				op_ok;
+	xfs_fsblock_t			end;
+
+	if (refc->pe_flags & ~XFS_REFCOUNT_EXTENT_FLAGS)
+		return false;
 
-	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;
+		return false;
 	}
-	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 (refc->pe_startblock + refc->pe_len <= refc->pe_startblock)
+		return false;
+
+	end = refc->pe_startblock + refc->pe_len - 1;
+	if (!xfs_verify_fsbno(mp, refc->pe_startblock) ||
+	    !xfs_verify_fsbno(mp, end))
 		return false;
 
 	return true;