On Fri, Nov 30, 2018 at 01:36:09PM -0700, Jens Axboe wrote: > On 11/30/18 1:26 PM, Keith Busch wrote: > > A driver may wish to iterate every tagged request, not just ones that > > satisfy blk_mq_request_started(). The intended use is so a driver may > > terminate entered requests on quiesced queues. > > How about we just move the started check into the handler passed in for > those that care about it? Much saner to make the interface iterate > everything, and leave whatever state check to the callback. So we used to do that, and I changed it back in May to test for MQ_RQ_IN_FLIGHT, and then Ming changed it to check blk_mq_request_started. So this is clearly a minefield of sorts.. Note that at least mtip32xx, nbd, skd and the various nvme transports want to use the function to terminate all requests in the error path, and it would be great to have one single understood, documented and debugged helper for that in the core, so this is a vote for moving more of the logic in your second helper into the core code. skd will need actually use ->complete to release resources for that, though and mtip plays some odd abort bits. If it weren't for the interesting abort behavior in nvme-fc that means we could even unexport the low-level interface.
