Re: [PATCH 2/2] nvmet: return Invalid Field for invalid NSIDs in Get Features 82h

[Christoph Hellwig <hch@lst.de>]

On Fri, Sep 18, 2026 at 11:39:32AM +0800, Guixin Liu wrote:
> The Reservation Notification Mask feature (FID 82h) rejects the same
> NSIDs for Get Features as for Set Features, plus the broadcast NSID:
> 
>   "A Get Features command that uses a namespace ID of FFFFFFFFh
>   shall be aborted with status code of Invalid Field in Command.
>   If a Set Features command or a Get Features command attempts to
>   access the Reservation Notification Mask on a namespace that does
>   not support reservations or is invalid, then that command is
>   aborted with status code of Invalid Field in Command."
> 
>   -- NVMe Base Specification, section 5.2.26.1.33
> 
> The Get Features handler routes the namespace lookup through
> nvmet_req_find_ns(), which returns Invalid Namespace or Format for an
> unknown NSID.  Both rejected cases land there: a nonexistent NSID
> fails the lookup, and so does the broadcast NSID, which never names a
> namespace.  Both are aborted with Invalid Namespace or Format instead
> of Invalid Field in Command.
> 
> Translate the lookup failure to Invalid Field in Command, as was done
> for Set Features.
> 
> Fixes: 5a47c2080a73 ("nvmet: support reservation feature")
> Signed-off-by: Guixin Liu <kanie@linux.alibaba.com>
> ---
>  drivers/nvme/target/pr.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/target/pr.c b/drivers/nvme/target/pr.c
> index 927e3c44952b..8762ef64aa46 100644
> --- a/drivers/nvme/target/pr.c
> +++ b/drivers/nvme/target/pr.c
> @@ -79,8 +79,12 @@ u16 nvmet_get_feat_resv_notif_mask(struct nvmet_req *req)
>  	u16 status;
>  
>  	status = nvmet_req_find_ns(req);
> -	if (status)
> +	if (status) {
> +		/* 82h is Invalid Field for invalid and broadcast NSIDs */
> +		if (status == (NVME_SC_INVALID_NS | NVME_STATUS_DNR))
> +			status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
>  		return status;
> +	}

Same thing about the comment, and I guess a direct return would
also make this a tiny bit more readable.