[PATCHv4 2/8] nvme: allow integrity on extended metadata formats

[Keith Busch <kbusch@kernel.org>]

The block integrity subsystem knows how to construct protection
information buffers with metadata beyond the protection information
fields. Remove the driver restriction.

Note, this can only work if the PI field appears first in the metadata,
as the integrity subsystem doesn't calculate guard tags on preceding
metadata.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 drivers/nvme/host/core.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index ace8c61850b1..ace5f30acaf6 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1754,12 +1754,9 @@ static void nvme_configure_metadata(struct nvme_ns *ns, struct nvme_id_ns *id)
 {
 	struct nvme_ctrl *ctrl = ns->ctrl;
 
-	/*
-	 * The PI implementation requires the metadata size to be equal to the
-	 * t10 pi tuple size.
-	 */
 	ns->ms = le16_to_cpu(id->lbaf[id->flbas & NVME_NS_FLBAS_LBA_MASK].ms);
-	if (ns->ms == sizeof(struct t10_pi_tuple))
+	if (id->dps & NVME_NS_DPS_PI_FIRST ||
+	    ns->ms == sizeof(struct t10_pi_tuple))
 		ns->pi_type = id->dps & NVME_NS_DPS_PI_MASK;
 	else
 		ns->pi_type = 0;
-- 
2.25.4