xfs: refactor cmp_key_with_cur routines to take advantage of cmp_int()

The net value of these functions is to determine the result of a
three-way-comparison between operands of the same type.

Simplify the code using cmp_int() to eliminate potential errors with
opencoded casts and subtractions. This also means we can change the return
value type of cmp_key_with_cur routines from int64_t to int and make the
interface a bit clearer.

Found by Linux Verification Center (linuxtesting.org).

Suggested-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

9 files changed, 30 insertions, 74 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c
index f371f1b32cfbe..fa1f03c1331e1 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.c
+++ b/fs/xfs/libxfs/xfs_alloc_btree.c
@@ -186,7 +186,7 @@ xfs_allocbt_init_ptr_from_cur(
 		ptr->s = agf->agf_cnt_root;
 }
 
-STATIC int64_t
+STATIC int
 xfs_bnobt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
@@ -194,23 +194,20 @@ xfs_bnobt_cmp_key_with_cur(
 	struct xfs_alloc_rec_incore	*rec = &cur->bc_rec.a;
 	const struct xfs_alloc_rec	*kp = &key->alloc;
 
-	return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
+	return cmp_int(be32_to_cpu(kp->ar_startblock),
+		       rec->ar_startblock);
 }
 
-STATIC int64_t
+STATIC int
 xfs_cntbt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
 {
 	struct xfs_alloc_rec_incore	*rec = &cur->bc_rec.a;
 	const struct xfs_alloc_rec	*kp = &key->alloc;
-	int64_t				diff;
-
-	diff = (int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
-	if (diff)
-		return diff;
 
-	return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
+	return cmp_int(be32_to_cpu(kp->ar_blockcount), rec->ar_blockcount) ?:
+	       cmp_int(be32_to_cpu(kp->ar_startblock), rec->ar_startblock);
 }
 
 STATIC int
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index bfe67e5d4d112..188feac04b603 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -369,13 +369,13 @@ xfs_bmbt_init_rec_from_cur(
 	xfs_bmbt_disk_set_all(&rec->bmbt, &cur->bc_rec.b);
 }
 
-STATIC int64_t
+STATIC int
 xfs_bmbt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
 {
-	return (int64_t)be64_to_cpu(key->bmbt.br_startoff) -
-				      cur->bc_rec.b.br_startoff;
+	return cmp_int(be64_to_cpu(key->bmbt.br_startoff),
+		       cur->bc_rec.b.br_startoff);
 }
 
 STATIC int
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index fecd9f0b93984..1bf20d509ac99 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -175,7 +175,7 @@ struct xfs_btree_ops {
 	 * Compare key value and cursor value -- positive if key > cur,
 	 * negative if key < cur, and zero if equal.
 	 */
-	int64_t (*cmp_key_with_cur)(struct xfs_btree_cur *cur,
+	int	(*cmp_key_with_cur)(struct xfs_btree_cur *cur,
 				    const union xfs_btree_key *key);
 
 	/*
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index ab9fce20b0838..100afdd66cdd5 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -265,13 +265,13 @@ xfs_finobt_init_ptr_from_cur(
 	ptr->s = agi->agi_free_root;
 }
 
-STATIC int64_t
+STATIC int
 xfs_inobt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
 {
-	return (int64_t)be32_to_cpu(key->inobt.ir_startino) -
-			  cur->bc_rec.i.ir_startino;
+	return cmp_int(be32_to_cpu(key->inobt.ir_startino),
+		       cur->bc_rec.i.ir_startino);
 }
 
 STATIC int
diff --git a/fs/xfs/libxfs/xfs_refcount_btree.c b/fs/xfs/libxfs/xfs_refcount_btree.c
index 1c3996b11563d..06da3ca14727a 100644
--- a/fs/xfs/libxfs/xfs_refcount_btree.c
+++ b/fs/xfs/libxfs/xfs_refcount_btree.c
@@ -174,7 +174,7 @@ xfs_refcountbt_init_ptr_from_cur(
 	ptr->s = agf->agf_refcount_root;
 }
 
-STATIC int64_t
+STATIC int
 xfs_refcountbt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
@@ -185,7 +185,7 @@ xfs_refcountbt_cmp_key_with_cur(
 
 	start = xfs_refcount_encode_startblock(irec->rc_startblock,
 			irec->rc_domain);
-	return (int64_t)be32_to_cpu(kp->rc_startblock) - start;
+	return cmp_int(be32_to_cpu(kp->rc_startblock), start);
 }
 
 STATIC int
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
index 3cccdb0d04182..bf16aee50d732 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -243,34 +243,18 @@ static inline uint64_t offset_keymask(uint64_t offset)
 	return offset & ~XFS_RMAP_OFF_UNWRITTEN;
 }
 
-STATIC int64_t
+STATIC int
 xfs_rmapbt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
 {
 	struct xfs_rmap_irec		*rec = &cur->bc_rec.r;
 	const struct xfs_rmap_key	*kp = &key->rmap;
-	__u64				x, y;
-	int64_t				d;
-
-	d = (int64_t)be32_to_cpu(kp->rm_startblock) - rec->rm_startblock;
-	if (d)
-		return d;
 
-	x = be64_to_cpu(kp->rm_owner);
-	y = rec->rm_owner;
-	if (x > y)
-		return 1;
-	else if (y > x)
-		return -1;
-
-	x = offset_keymask(be64_to_cpu(kp->rm_offset));
-	y = offset_keymask(xfs_rmap_irec_offset_pack(rec));
-	if (x > y)
-		return 1;
-	else if (y > x)
-		return -1;
-	return 0;
+	return cmp_int(be32_to_cpu(kp->rm_startblock), rec->rm_startblock) ?:
+	       cmp_int(be64_to_cpu(kp->rm_owner), rec->rm_owner) ?:
+	       cmp_int(offset_keymask(be64_to_cpu(kp->rm_offset)),
+		       offset_keymask(xfs_rmap_irec_offset_pack(rec)));
 }
 
 STATIC int
diff --git a/fs/xfs/libxfs/xfs_rtrefcount_btree.c b/fs/xfs/libxfs/xfs_rtrefcount_btree.c
index d9f79ae579c69..ac11e94b42ae3 100644
--- a/fs/xfs/libxfs/xfs_rtrefcount_btree.c
+++ b/fs/xfs/libxfs/xfs_rtrefcount_btree.c
@@ -156,7 +156,7 @@ xfs_rtrefcountbt_init_ptr_from_cur(
 	ptr->l = 0;
 }
 
-STATIC int64_t
+STATIC int
 xfs_rtrefcountbt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
@@ -167,7 +167,7 @@ xfs_rtrefcountbt_cmp_key_with_cur(
 
 	start = xfs_refcount_encode_startblock(irec->rc_startblock,
 			irec->rc_domain);
-	return (int64_t)be32_to_cpu(kp->rc_startblock) - start;
+	return cmp_int(be32_to_cpu(kp->rc_startblock), start);
 }
 
 STATIC int
diff --git a/fs/xfs/libxfs/xfs_rtrmap_btree.c b/fs/xfs/libxfs/xfs_rtrmap_btree.c
index 231a189ea2fe6..55f9031657695 100644
--- a/fs/xfs/libxfs/xfs_rtrmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rtrmap_btree.c
@@ -185,34 +185,18 @@ static inline uint64_t offset_keymask(uint64_t offset)
 	return offset & ~XFS_RMAP_OFF_UNWRITTEN;
 }
 
-STATIC int64_t
+STATIC int
 xfs_rtrmapbt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
 {
 	struct xfs_rmap_irec		*rec = &cur->bc_rec.r;
 	const struct xfs_rmap_key	*kp = &key->rmap;
-	__u64				x, y;
-	int64_t				d;
-
-	d = (int64_t)be32_to_cpu(kp->rm_startblock) - rec->rm_startblock;
-	if (d)
-		return d;
 
-	x = be64_to_cpu(kp->rm_owner);
-	y = rec->rm_owner;
-	if (x > y)
-		return 1;
-	else if (y > x)
-		return -1;
-
-	x = offset_keymask(be64_to_cpu(kp->rm_offset));
-	y = offset_keymask(xfs_rmap_irec_offset_pack(rec));
-	if (x > y)
-		return 1;
-	else if (y > x)
-		return -1;
-	return 0;
+	return cmp_int(be32_to_cpu(kp->rm_startblock), rec->rm_startblock) ?:
+	       cmp_int(be64_to_cpu(kp->rm_owner), rec->rm_owner) ?:
+	       cmp_int(offset_keymask(be64_to_cpu(kp->rm_offset)),
+		       offset_keymask(xfs_rmap_irec_offset_pack(rec)));
 }
 
 STATIC int
diff --git a/fs/xfs/scrub/rcbag_btree.c b/fs/xfs/scrub/rcbag_btree.c
index 46598817b2391..9a4ef823c5a7f 100644
--- a/fs/xfs/scrub/rcbag_btree.c
+++ b/fs/xfs/scrub/rcbag_btree.c
@@ -47,7 +47,7 @@ rcbagbt_init_rec_from_cur(
 	bag_rec->rbg_refcount = bag_irec->rbg_refcount;
 }
 
-STATIC int64_t
+STATIC int
 rcbagbt_cmp_key_with_cur(
 	struct xfs_btree_cur		*cur,
 	const union xfs_btree_key	*key)
@@ -55,17 +55,8 @@ rcbagbt_cmp_key_with_cur(
 	struct rcbag_rec		*rec = (struct rcbag_rec *)&cur->bc_rec;
 	const struct rcbag_key		*kp = (const struct rcbag_key *)key;
 
-	if (kp->rbg_startblock > rec->rbg_startblock)
-		return 1;
-	if (kp->rbg_startblock < rec->rbg_startblock)
-		return -1;
-
-	if (kp->rbg_blockcount > rec->rbg_blockcount)
-		return 1;
-	if (kp->rbg_blockcount < rec->rbg_blockcount)
-		return -1;
-
-	return 0;
+	return cmp_int(kp->rbg_startblock, rec->rbg_startblock) ?:
+	       cmp_int(kp->rbg_blockcount, rec->rbg_blockcount);
 }
 
 STATIC int