nvme: fix PI insert on write
I recently ran into an issue where the PI generated using the block layer
integrity code differs from that from a kernel using the PRACT fallback
when the block layer integrity code is disabled, and I tracked this down
to us using PRACT incorrectly.
The NVM Command Set Specification (section 5.33 in 1.2, similar in older
versions) specifies the PRACT insert behavior as:
Inserted protection information consists of the computed CRC for the
protection information format (refer to section 5.3.1) in the Guard
field, the LBAT field value in the Application Tag field, the LBST
field value in the Storage Tag field, if defined, and the computed
reference tag in the Logical Block Reference Tag.
Where the computed reference tag is defined as following for type 1 and
type 2 using the text below that is duplicated in the respective bullet
points:
the value of the computed reference tag for the first logical block of
the command is the value contained in the Initial Logical Block
Reference Tag (ILBRT) or Expected Initial Logical Block Reference Tag
(EILBRT) field in the command, and the computed reference tag is
incremented for each subsequent logical block.
So we need to set ILBRT field, but we currently don't. Interestingly
this works fine on my older type 1 formatted SSD, but Qemu trips up on
this. We already set ILBRT for Write Same since commit aeb7bb061be5
("nvme: set the PRACT bit when using Write Zeroes with T10 PI").
To ease this, move the PI type check into nvme_set_ref_tag.
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 812c156..6b74939 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -903,6 +903,15 @@ static void nvme_set_ref_tag(struct nvme_ns *ns, struct nvme_command *cmnd,
u32 upper, lower;
u64 ref48;
+ /* only type1 and type 2 PI formats have a reftag */
+ switch (ns->head->pi_type) {
+ case NVME_NS_DPS_PI_TYPE1:
+ case NVME_NS_DPS_PI_TYPE2:
+ break;
+ default:
+ return;
+ }
+
/* both rw and write zeroes share the same reftag format */
switch (ns->head->guard_type) {
case NVME_NVM_NS_16B_GUARD:
@@ -942,13 +951,7 @@ static inline blk_status_t nvme_setup_write_zeroes(struct nvme_ns *ns,
if (nvme_ns_has_pi(ns->head)) {
cmnd->write_zeroes.control |= cpu_to_le16(NVME_RW_PRINFO_PRACT);
-
- switch (ns->head->pi_type) {
- case NVME_NS_DPS_PI_TYPE1:
- case NVME_NS_DPS_PI_TYPE2:
- nvme_set_ref_tag(ns, cmnd, req);
- break;
- }
+ nvme_set_ref_tag(ns, cmnd, req);
}
return BLK_STS_OK;
@@ -1039,6 +1042,7 @@ static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns,
if (WARN_ON_ONCE(!nvme_ns_has_pi(ns->head)))
return BLK_STS_NOTSUPP;
control |= NVME_RW_PRINFO_PRACT;
+ nvme_set_ref_tag(ns, cmnd, req);
}
if (bio_integrity_flagged(req->bio, BIP_CHECK_GUARD))
