Re: can we drop the bio based path in null_blk

[Pankaj Raghav <p.raghav@samsung.com>]

On 25/01/2024 09:15, Christoph Hellwig wrote:
> On Wed, Jan 24, 2024 at 09:31:25PM +0100, Pankaj Raghav (Samsung) wrote:
>> The subject says removing the bio mode in null_blk but here you are
>> asking an open question about the non-so-relevant ones should move to
>> blk-mq. My input is for the latter part, FWIW.
> 
> Well, it's two different things.  My prime concern right now is
> null_blk, which is very clumsy due to the two different I/O paths,
> and actually broken in that the bio mode doesn't respect various
> I/O limits that can be configured, and at least in zone modes also
> ones that aren't configured but required (I/Os spanning zones).
> 

My 2 cents: The drivers that still use submit_bio are mostly memory
based except for n64. And there is only one blktest(block/023) that
tests the bio path (Shinchiro can comment here if this is wrong).

So we could remove the submit_bio path in null_blk to simplify things
as most of the drivers that uses this path do not do anything complicated
in submit_bio and are mostly memory based.

--
Pankaj Raghav