[PATCH] nvmet: propagate npwg and awupf topology

[PATCH] nvmet: propagate npwg and awupf topology

[Luis Chamberlain]

Ensure we propagate npwg and awupf to the target as well instead
of assuming its the same logical blocks per physical block.

This ensures devices with large IUs and large atomics get their
information properly propagated on the target.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 drivers/nvme/target/io-cmd-bdev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
index 0bda83d0fc3e..567e5ac49fb0 100644
--- a/drivers/nvme/target/io-cmd-bdev.c
+++ b/drivers/nvme/target/io-cmd-bdev.c
@@ -26,7 +26,8 @@ void nvmet_bdev_set_limits(struct block_device *bdev, struct nvme_id_ns *id)
 	 */
 	id->nsfeat |= 1 << 1;
 	id->nawun = lpp0b;
-	id->nawupf = lpp0b;
+	id->nawupf = to0based(bdev_atomic_write_unit_max_bytes(bdev) /
+			      bdev_logical_block_size(bdev));
 	id->nacwu = lpp0b;
 
 	/*
@@ -36,7 +37,7 @@ void nvmet_bdev_set_limits(struct block_device *bdev, struct nvme_id_ns *id)
 	 */
 	id->nsfeat |= 1 << 4;
 	/* NPWG = Namespace Preferred Write Granularity. 0's based */
-	id->npwg = lpp0b;
+	id->npwg = to0based(bdev_io_min(bdev) / bdev_logical_block_size(bdev));
 	/* NPWA = Namespace Preferred Write Alignment. 0's based */
 	id->npwa = id->npwg;
 	/* NPDG = Namespace Preferred Deallocate Granularity. 0's based */
-- 
2.45.2

Re: [PATCH] nvmet: propagate npwg and awupf topology

[Christoph Hellwig]

On Wed, Dec 11, 2024 at 07:31:47PM -0800, Luis Chamberlain wrote:
> Ensure we propagate npwg and awupf to the target as well instead
> of assuming its the same logical blocks per physical block.
> 
> This ensures devices with large IUs and large atomics get their
> information properly propagated on the target.

nvmet never sets REQ_ATOMIC and thus won't get atomic writes from
say SCSI.  So supporting atomic writes is a little more work than
just propagating the values.

Re: [PATCH] nvmet: propagate npwg and awupf topology

[John Garry]

On 12/12/2024 05:52, Christoph Hellwig wrote:
> On Wed, Dec 11, 2024 at 07:31:47PM -0800, Luis Chamberlain wrote:
>> Ensure we propagate npwg and awupf to the target as well instead
>> of assuming its the same logical blocks per physical block.
>>
>> This ensures devices with large IUs and large atomics get their
>> information properly propagated on the target.
> 
> nvmet never sets REQ_ATOMIC and thus won't get atomic writes from
> say SCSI.  So supporting atomic writes is a little more work than
> just propagating the values.
> 

In case missed, Mike had patches for SCSI target code:
https://lore.kernel.org/linux-scsi/20241008020437.78788-1-michael.christie@oracle.com/

I still need to check them ...

Re: [PATCH] nvmet: propagate npwg and awupf topology

[Luis Chamberlain]

On Thu, Dec 12, 2024 at 11:25:29AM +0000, John Garry wrote:
> I still need to check them ...

We can punt atomics later then.

 Luis