[PATCH v2 6/6] xfs: refactor xfs_btree_diff_two_ptrs() to take advantage of cmp_int()

[Fedor Pchelkin <pchelkin@ispras.ru>]

Use cmp_int() to yield the result of a three-way-comparison instead of
performing subtractions with extra casts. Thus also rename the function
to make its name clearer in purpose.

Found by Linux Verification Center (linuxtesting.org).

Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
---

v2: rename the "diff_two_ptrs" part (Darrick)

 fs/xfs/libxfs/xfs_btree.c | 8 ++++----
 fs/xfs/libxfs/xfs_btree.h | 6 +++---
 fs/xfs/scrub/btree.c      | 2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index d3591728998e..a61211d253f1 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -5353,15 +5353,15 @@ xfs_btree_count_blocks(
 }
 
 /* Compare two btree pointers. */
-int64_t
-xfs_btree_diff_two_ptrs(
+int
+xfs_btree_cmp_two_ptrs(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_ptr	*a,
 	const union xfs_btree_ptr	*b)
 {
 	if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
-		return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l);
-	return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s);
+		return cmp_int(be64_to_cpu(a->l), be64_to_cpu(b->l));
+	return cmp_int(be32_to_cpu(a->s), be32_to_cpu(b->s));
 }
 
 struct xfs_btree_has_records {
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 1bf20d509ac9..60e78572e725 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -519,9 +519,9 @@ struct xfs_btree_block *xfs_btree_get_block(struct xfs_btree_cur *cur,
 		int level, struct xfs_buf **bpp);
 bool xfs_btree_ptr_is_null(struct xfs_btree_cur *cur,
 		const union xfs_btree_ptr *ptr);
-int64_t xfs_btree_diff_two_ptrs(struct xfs_btree_cur *cur,
-				const union xfs_btree_ptr *a,
-				const union xfs_btree_ptr *b);
+int xfs_btree_cmp_two_ptrs(struct xfs_btree_cur *cur,
+			   const union xfs_btree_ptr *a,
+			   const union xfs_btree_ptr *b);
 void xfs_btree_get_sibling(struct xfs_btree_cur *cur,
 			   struct xfs_btree_block *block,
 			   union xfs_btree_ptr *ptr, int lr);
diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c
index fe678a0438bc..cd6f0ff382a7 100644
--- a/fs/xfs/scrub/btree.c
+++ b/fs/xfs/scrub/btree.c
@@ -306,7 +306,7 @@ xchk_btree_block_check_sibling(
 	if (pbp)
 		xchk_buffer_recheck(bs->sc, pbp);
 
-	if (xfs_btree_diff_two_ptrs(cur, pp, sibling))
+	if (xfs_btree_cmp_two_ptrs(cur, pp, sibling))
 		xchk_btree_set_corrupt(bs->sc, cur, level);
 out:
 	xfs_btree_del_cursor(ncur, XFS_BTREE_ERROR);
-- 
2.50.0