blk-mq timeout question

From	Stefan Haberland <sth@linux.vnet.ibm.com>
Newsgroups	linux.kernel
Subject	blk-mq timeout question
Date	2017-07-07 15:50 +0200
Message-ID	<u0BNU-4Ks-7@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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While changing the DASD device driver to use the blk-mq interfaces I 
found the following unexpected behavior:

In case of a timeout our complete callback is never called. Here is the 
sequence of events as I understood:

- timeout occurs
- blk_mq_check_expired() calls and checks blk_mark_rq_complete()
- our .timeout callback is called which returns BLK_EH_NOT_HANDLED and 
schedules delayed work
- our worker calls blk_mq_complete_request()
- this also checks blk_mark_rq_complete() and therefore never calls our 
complete callback

Question:
Should blk_clear_rq_complete() also be called for the BLK_EH_NOT_HANDLED 
case?

Regards,
Stefan

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blk-mq timeout question Stefan Haberland <sth@linux.vnet.ibm.com> - 2017-07-07 15:50 +0200
  Re: blk-mq timeout question Ming Lei <tom.leiming@gmail.com> - 2017-07-10 04:30 +0200

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