dm: simplify __process_abnormal_io()

Only call bio_op() once in switch statement.  Also remove the
excessive factoring out to one line functions.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

drivers/md/dm.c

@@ -1474,28 +1474,6 @@ static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
 	return 0;
 }
 
-typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);
-
-static unsigned get_num_discard_bios(struct dm_target *ti)
-{
-	return ti->num_discard_bios;
-}
-
-static unsigned get_num_secure_erase_bios(struct dm_target *ti)
-{
-	return ti->num_secure_erase_bios;
-}
-
-static unsigned get_num_write_same_bios(struct dm_target *ti)
-{
-	return ti->num_write_same_bios;
-}
-
-static unsigned get_num_write_zeroes_bios(struct dm_target *ti)
-{
-	return ti->num_write_zeroes_bios;
-}
-
 static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *ti,
 				       unsigned num_bios)
 {
@@ -1521,26 +1499,6 @@ static int __send_changing_extent_only(struct clone_info *ci, struct dm_target *
 	return 0;
 }
 
-static int __send_discard(struct clone_info *ci, struct dm_target *ti)
-{
-	return __send_changing_extent_only(ci, ti, get_num_discard_bios(ti));
-}
-
-static int __send_secure_erase(struct clone_info *ci, struct dm_target *ti)
-{
-	return __send_changing_extent_only(ci, ti, get_num_secure_erase_bios(ti));
-}
-
-static int __send_write_same(struct clone_info *ci, struct dm_target *ti)
-{
-	return __send_changing_extent_only(ci, ti, get_num_write_same_bios(ti));
-}
-
-static int __send_write_zeroes(struct clone_info *ci, struct dm_target *ti)
-{
-	return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios(ti));
-}
-
 static bool is_abnormal_io(struct bio *bio)
 {
 	bool r = false;
@@ -1561,18 +1519,26 @@ static bool __process_abnormal_io(struct clone_info *ci, struct dm_target *ti,
 				  int *result)
 {
 	struct bio *bio = ci->bio;
+	unsigned num_bios = 0;
 
-	if (bio_op(bio) == REQ_OP_DISCARD)
-		*result = __send_discard(ci, ti);
-	else if (bio_op(bio) == REQ_OP_SECURE_ERASE)
-		*result = __send_secure_erase(ci, ti);
-	else if (bio_op(bio) == REQ_OP_WRITE_SAME)
-		*result = __send_write_same(ci, ti);
-	else if (bio_op(bio) == REQ_OP_WRITE_ZEROES)
-		*result = __send_write_zeroes(ci, ti);
-	else
+	switch (bio_op(bio)) {
+	case REQ_OP_DISCARD:
+		num_bios = ti->num_discard_bios;
+		break;
+	case REQ_OP_SECURE_ERASE:
+		num_bios = ti->num_secure_erase_bios;
+		break;
+	case REQ_OP_WRITE_SAME:
+		num_bios = ti->num_write_same_bios;
+		break;
+	case REQ_OP_WRITE_ZEROES:
+		num_bios = ti->num_write_zeroes_bios;
+		break;
+	default:
 		return false;
+	}
 
+	*result = __send_changing_extent_only(ci, ti, num_bios);
 	return true;
 }