[PATCH] nvme: allow ioctl to submit io command with dif for NVMeoF

[Chao Leng]

Hi, Keith
     Any other comments on this patch?
     Is there any chance that this patch can be accepted?

On 2022/8/4 11:00, Chao Leng wrote:
> 
> 
> On 2022/8/3 23:44, Keith Busch wrote:
>> On Wed, Aug 03, 2022 at 05:44:36PM +0800, Chao Leng wrote:
>>> If nvme over fabrics support t10dif, NVME_NS_EXT_LBAS and
>>> NVME_NS_METADATA_SUPPORTED of ns->features will be set to 1.
>>> Now nvme_submit_io do not allow the metadata if NVME_NS_EXT_LBAS of
>>> ns->features is setted. Indeed It should allow the metadata if both
>>> NVME_NS_EXT_LBAS and NVME_NS_METADATA_SUPPORTED of ns->features are setted.
>>
>> I'm not sure. As a passthrough interface, don't you want to set up the host
>> buffers with the inline metadata instead of relying on the HBA to splice
>> separate ones?
> If HBA support t10DIF, we need the HBA to verify the metadata for end-to-end DIF.
> So we need set up the metadata separately.
> Two scenarios:
> 1.Test whether the HBA verification meets expectations when specify data and metadata.
> 2.The user wants to use the capability of end-to-end DIF through IOCTL.
> If the HBA does not support T10DIF, Keep the old behavior.
>>
>> If you really want to control this kind of thing, it would be better to use
>> NVME_IOCTL_IO_CMD instead of NVME_IOCTL_SUBMIT_IO.
> NVME_IOCTL_IO_CMD is a universal interface, of course, it can work well.
> But nvme-cli do not support customized commands, and it is not friendly to use.
> We can use nvme write/read simply, it looks better.
>> .
>>
> 
> .