Re: [PATCH v3 09/19] nvme: Add pr_ops read_keys support

Christoph Hellwig
2022-10-30T08:17:20Z

On Wed, Oct 26, 2022 at 06:19:35PM -0500, Mike Christie wrote:
> This patch adds support for the pr_ops read_keys callout by calling the
> NVMe Reservation Report helper, then parsing that info to get the
> controller's registered keys. Because the callout is only used in the
> kernel where the callers do not know about controller/host IDs, the
> callout just returns the registered keys which is required by the SCSI PR
> in READ KEYS command.
>
> Signed-off-by: Mike Christie <michael.christie@oracle.com>
> ---
> drivers/nvme/host/pr.c | 73 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/nvme.h | 4 +++
> 2 files changed, 77 insertions(+)
>
> diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
> index aa88c55879b2..df7eb2440c67 100644
> --- a/drivers/nvme/host/pr.c
> +++ b/drivers/nvme/host/pr.c
> @@ -118,10 +118,83 @@ static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type
> return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
> }
>
> +static int nvme_pr_resv_report(struct block_device *bdev, u8 *data,
> + u32 data_len, bool *eds)

Is there any good reason this method seems to take a u8 instead of a void
pointer? As that seems to make a few things a bit messy.

> + if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
> + bdev->bd_disk->fops == &nvme_ns_head_ops)
> + ret = nvme_send_ns_head_pr_command(bdev, &c, data, data_len);
> + else
> + ret = nvme_send_ns_pr_command(bdev->bd_disk->private_data, &c,
> + data, data_len);

Can you please add a hlper for this logic?

> + for (i = 0; i < num_ret_keys; i++) {
> + if (eds) {
> + keys_info->keys[i] =
> + le64_to_cpu(status->regctl_eds[i].rkey);
> + } else {
> + keys_info->keys[i] =
> + le64_to_cpu(status->regctl_ds[i].rkey);
> + }

If you shorten the status variable name to something like rs this becomes
much easier to follow :)