[PATCH v4 2/3] block: don't remap ref tag for T10 PI type 0

[Max Gurtovoy <maxg@mellanox.com>]

Only type 1 and type 2 have a reference tag by definition.

Suggested-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
---

changes from v3:
 - added blk_integrity_need_remap helper

---
 block/t10-pi.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/block/t10-pi.c b/block/t10-pi.c
index a33eac4..753b5a8 100644
--- a/block/t10-pi.c
+++ b/block/t10-pi.c
@@ -168,6 +168,12 @@ static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
 };
 EXPORT_SYMBOL(t10_pi_type3_ip);
 
+static inline bool blk_integrity_need_remap(struct gendisk *disk)
+{
+	return disk->protection_type == T10_PI_TYPE1_PROTECTION ||
+		disk->protection_type == T10_PI_TYPE2_PROTECTION;
+}
+
 /**
  * t10_pi_prepare - prepare PI prior submitting request to device
  * @rq:              request with PI that should be prepared
@@ -178,7 +184,7 @@ static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
  * likely to be different. Remap protection information to match the
  * physical LBA.
  *
- * Type 3 does not have a reference tag so no remapping is required.
+ * Types 0 and 3 don't have a reference tag so no remapping is required.
  */
 void t10_pi_prepare(struct request *rq)
 {
@@ -186,7 +192,7 @@ void t10_pi_prepare(struct request *rq)
 	u32 ref_tag = t10_pi_ref_tag(rq);
 	struct bio *bio;
 
-	if (rq->rq_disk->protection_type == T10_PI_TYPE3_PROTECTION)
+	if (!blk_integrity_need_remap(rq->rq_disk))
 		return;
 
 	__rq_for_each_bio(bio, rq) {
@@ -234,7 +240,7 @@ void t10_pi_prepare(struct request *rq)
  * to the device, we should remap it back to virtual values expected by the
  * block layer.
  *
- * Type 3 does not have a reference tag so no remapping is required.
+ * Types 0 and 3 don't have a reference tag so no remapping is required.
  */
 void t10_pi_complete(struct request *rq, unsigned int nr_bytes)
 {
@@ -243,7 +249,7 @@ void t10_pi_complete(struct request *rq, unsigned int nr_bytes)
 	u32 ref_tag = t10_pi_ref_tag(rq);
 	struct bio *bio;
 
-	if (rq->rq_disk->protection_type == T10_PI_TYPE3_PROTECTION)
+	if (!blk_integrity_need_remap(rq->rq_disk))
 		return;
 
 	__rq_for_each_bio(bio, rq) {
-- 
1.8.3.1