misc: fix unsigned integer comparison complaints

gcc 11.2 complains about certain variables now that xfs_extnum_t is an
unsigned 64-bit integer:

dinode.c: In function ‘process_exinode’:
dinode.c:960:21: error: comparison of unsigned expression in ‘< 0’ is always false [-Werror=type-limits]
  960 |         if (numrecs < 0)

Since we actually have a function that will tell us the maximum
supported extent count for an ondisk dinode structure, use a direct
comparison instead of tricky integer math to detect overflows.  A more
exhaustive audit is probably necessary.

IOWS, shut up, gcc...

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

3 files changed, 24 insertions, 11 deletions

diff --git a/db/check.c b/db/check.c
index fb28994d05..c9149daadf 100644
--- a/db/check.c
+++ b/db/check.c
@@ -2711,14 +2711,18 @@ process_exinode(
 	int			whichfork)
 {
 	xfs_bmbt_rec_t		*rp;
+	xfs_extnum_t		max_nex;
 
 	rp = (xfs_bmbt_rec_t *)XFS_DFORK_PTR(dip, whichfork);
 	*nex = xfs_dfork_nextents(dip, whichfork);
-	if (*nex < 0 || *nex > XFS_DFORK_SIZE(dip, mp, whichfork) /
+	max_nex = xfs_iext_max_nextents(
+			xfs_dinode_has_large_extent_counts(dip),
+			whichfork);
+	if (*nex > max_nex || *nex > XFS_DFORK_SIZE(dip, mp, whichfork) /
 						sizeof(xfs_bmbt_rec_t)) {
 		if (!sflag || id->ilist)
-			dbprintf(_("bad number of extents %d for inode %lld\n"),
-				*nex, id->ino);
+			dbprintf(_("bad number of extents %llu for inode %lld\n"),
+				(unsigned long long)*nex, id->ino);
 		error++;
 		return;
 	}
diff --git a/db/metadump.c b/db/metadump.c
index 999c68f7ec..27d1df4327 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -2278,16 +2278,19 @@ process_exinode(
 {
 	int			whichfork;
 	int			used;
-	xfs_extnum_t		nex;
+	xfs_extnum_t		nex, max_nex;
 
 	whichfork = (itype == TYP_ATTR) ? XFS_ATTR_FORK : XFS_DATA_FORK;
 
 	nex = xfs_dfork_nextents(dip, whichfork);
+	max_nex = xfs_iext_max_nextents(
+			xfs_dinode_has_large_extent_counts(dip),
+			whichfork);
 	used = nex * sizeof(xfs_bmbt_rec_t);
-	if (nex < 0 || used > XFS_DFORK_SIZE(dip, mp, whichfork)) {
+	if (nex > max_nex || used > XFS_DFORK_SIZE(dip, mp, whichfork)) {
 		if (show_warnings)
-			print_warning("bad number of extents %d in inode %lld",
-				nex, (long long)cur_ino);
+			print_warning("bad number of extents %llu in inode %lld",
+				(unsigned long long)nex, (long long)cur_ino);
 		return 1;
 	}
 
diff --git a/repair/dinode.c b/repair/dinode.c
index 04e7f83e82..00de31fb12 100644
--- a/repair/dinode.c
+++ b/repair/dinode.c
@@ -942,7 +942,7 @@ process_exinode(
 	xfs_bmbt_rec_t		*rp;
 	xfs_fileoff_t		first_key;
 	xfs_fileoff_t		last_key;
-	xfs_extnum_t		numrecs;
+	xfs_extnum_t		numrecs, max_numrecs;
 	int			ret;
 
 	lino = XFS_AGINO_TO_INO(mp, agno, ino);
@@ -956,7 +956,10 @@ process_exinode(
 	 * be in the range of valid on-disk numbers, which is:
 	 *	0 < numrecs < 2^31 - 1
 	 */
-	if (numrecs < 0)
+	max_numrecs = xfs_iext_max_nextents(
+			xfs_dinode_has_large_extent_counts(dip),
+			whichfork);
+	if (numrecs > max_numrecs)
 		numrecs = *nex;
 
 	/*
@@ -1899,7 +1902,7 @@ process_inode_data_fork(
 {
 	xfs_ino_t		lino = XFS_AGINO_TO_INO(mp, agno, ino);
 	int			err = 0;
-	xfs_extnum_t		nex;
+	xfs_extnum_t		nex, max_nex;
 
 	/*
 	 * extent count on disk is only valid for positive values. The kernel
@@ -1907,7 +1910,10 @@ process_inode_data_fork(
 	 * here, trash it!
 	 */
 	nex = xfs_dfork_data_extents(dino);
-	if (nex < 0)
+	max_nex = xfs_iext_max_nextents(
+			xfs_dinode_has_large_extent_counts(dino),
+			XFS_DATA_FORK);
+	if (nex > max_nex)
 		*nextents = 1;
 	else
 		*nextents = nex;