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Diffstat (limited to 'fs/xfs/libxfs/xfs_bmap_btree.c')
-rw-r--r--fs/xfs/libxfs/xfs_bmap_btree.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index fbb18ba5d905..ffe608d2a2d9 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -400,8 +400,20 @@ xfs_bmbt_diff_two_keys(
union xfs_btree_key *k1,
union xfs_btree_key *k2)
{
- return (int64_t)be64_to_cpu(k1->bmbt.br_startoff) -
- be64_to_cpu(k2->bmbt.br_startoff);
+ uint64_t a = be64_to_cpu(k1->bmbt.br_startoff);
+ uint64_t b = be64_to_cpu(k2->bmbt.br_startoff);
+
+ /*
+ * Note: This routine previously casted a and b to int64 and subtracted
+ * them to generate a result. This lead to problems if b was the
+ * "maximum" key value (all ones) being signed incorrectly, hence this
+ * somewhat less efficient version.
+ */
+ if (a > b)
+ return 1;
+ if (b > a)
+ return -1;
+ return 0;
}
static xfs_failaddr_t