[PATCH v2 3/3] nvme: allow integrity when PI is not in first bytes

[Kanchan Joshi]

NVM command set 1.0 (or later) mandates PI to be in the last bytes of
metadata. But this was not supported in the block-layer, and driver
registered a nop profile.

Since block-integrity can now handle flexible PI offset, change the
driver to support this configuration.

Signed-off-by: Kanchan Joshi <joshi.k at samsung.com>
Reviewed-by: Sagi Grimberg <sagi at grimberg.me>
Reviewed-by: Keith Busch <kbusch at kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen at oracle.com>
---
 drivers/nvme/host/core.c | 8 +++++++-
 drivers/nvme/host/nvme.h | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 85ab0fcf9e88..4945d6259a13 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1726,6 +1726,7 @@ static void nvme_init_integrity(struct gendisk *disk,
 	}
 
 	integrity.tuple_size = head->ms;
+	integrity.pi_offset = head->pi_offset;
 	blk_integrity_register(disk, &integrity);
 	blk_queue_max_integrity_segments(disk->queue, max_integrity_segments);
 }
@@ -1835,11 +1836,16 @@ static int nvme_init_ms(struct nvme_ctrl *ctrl, struct nvme_ns_head *head,
 free_data:
 	kfree(nvm);
 set_pi:
-	if (head->pi_size && (first || head->ms == head->pi_size))
+	if (head->pi_size && head->ms >= head->pi_size)
 		head->pi_type = id->dps & NVME_NS_DPS_PI_MASK;
 	else
 		head->pi_type = 0;
 
+	if (first)
+		head->pi_offset = 0;
+	else
+		head->pi_offset = head->ms - head->pi_size;
+
 	return ret;
 }
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 030c80818240..281657320c3a 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -462,6 +462,7 @@ struct nvme_ns_head {
 	u16			ms;
 	u16			pi_size;
 	u8			pi_type;
+	u8			pi_offset;
 	u8			guard_type;
 	u16			sgs;
 	u32			sws;
-- 
2.25.1