Re: [dm-devel] [PATCH v5] blk-mq: introduce BLK_STS_DEV_RESOURCE

On Tue, Jan 30, 2018 at 08:22:27PM -0700, Jens Axboe wrote:

On 1/30/18 8:21 PM, Bart Van Assche wrote:

quoted

On Tue, 2018-01-30 at 20:17 -0700, Jens Axboe wrote:

quoted

BLK_STS_RESOURCE should always be safe to return, and it should work
the same as STS_DEV_RESOURCE, except it may cause an extra queue
run.

Well written drivers should use STS_DEV_RESOURCE where it makes
sense.

Hello Jens,

I would appreciate it if other names would be chosen than BLK_STS_RESOURCE
and BLK_STS_DEV_RESOURCE, e.g. names that directly refer to the fact that
one of the two status codes causes the queue to be rerun and the other not.
I'm afraid that the currently chosen names will cause confusion.

DEV_RESOURCE is pretty clear I think, but I agree that STS_RESOURCE
could perhaps be better. STS_SYSTEM_RESOURCE? It makes the distinction

I guess it still can't cover all, for example, .queue_rq() may not
submit rq to hardware successfully because of tansport busy, such FC,..

-- 
Ming