From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Mon, 30 Nov 2020 00:33:37 +0000 (-0800)
Subject: xfs: improve the code that checks recovered refcount intent items
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0d79781a1aa6a6a567e63294012eee2384f406f2;p=linux.git

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.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
---

diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c
index e19f96c9b93a2..c24f2da0f795b 100644
--- a/fs/xfs/xfs_refcount_item.c
+++ b/fs/xfs/xfs_refcount_item.c
@@ -423,27 +423,26 @@ xfs_cui_validate_phys(
 	struct xfs_mount		*mp,
 	struct xfs_phys_extent		*refc)
 {
-	xfs_fsblock_t			startblock_fsb;
-	bool				op_ok;
+	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;
+
+	if (!xfs_verify_fsbno(mp, refc->pe_startblock))
+		return false;
+
+	if (!xfs_verify_fsbno(mp, refc->pe_startblock + refc->pe_len - 1))
 		return false;
 
 	return true;