discard cmd through ioctl

[sheng qiu]

Hi Keith,

thanks for your reply.
for the struct "nvme_passthru_cmd", can you tell me what's the "flags"
and "rsvd1" used for? which cmd filed does it associated to the NVMe
Spec?

just want to make sure i am composing the correct cmd format.

THanks!
Sheng

On Fri, Feb 6, 2015 at 12:02 PM, Keith Busch <keith.busch at intel.com> wrote:
> On Fri, 6 Feb 2015, sheng qiu wrote:
>>
>> Hi,
>>
>> May i ask is there a way to issue data set management cmd from
>> application to achieve discard function with current NVMe driver?
>>
>> i see there are regular IO or Admin interface for ioctl at driver
>> side. Is this also applicable to dsm cmd?
>
>
> Sure, you can use the NVME_IOCTL_IO_CMD to submit any arbitary IO command
> you like.
>
> It would probably be easier to use sg_unmap or blkdiscard to achieve the
> same thing unless you require using the DSM command's other attributes
> in addition to deallocate.
>
>> Thanks,
>> Sheng