On 4/24/18 3:00 PM, kernel test robot wrote: > Greetings, > > 0day kernel testing robot got the below dmesg and the first bad commit is > > https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-linus > > commit ed74ae03424684a6ad8a973c3fa727c6b4162432 > Author: Bart Van Assche <bart.vanassche@xxxxxxx> > AuthorDate: Thu Apr 19 09:43:53 2018 -0700 > Commit: Jens Axboe <axboe@xxxxxxxxx> > CommitDate: Thu Apr 19 14:21:47 2018 -0600 > > blk-mq: Avoid that a completion can be ignored for BLK_EH_RESET_TIMER > > The blk-mq timeout handling code ignores completions that occur after > blk_mq_check_expired() has been called and before blk_mq_rq_timed_out() > has reset rq->aborted_gstate. If a block driver timeout handler always > returns BLK_EH_RESET_TIMER then the result will be that the request > never terminates. > > Fix this race as follows: > - Use the deadline instead of the request generation to detect whether > or not a request timer fired after reinitialization of a request. > - Store the request state in the lowest two bits of the deadline instead > of the lowest two bits of 'gstate'. > - Rename MQ_RQ_STATE_MASK into RQ_STATE_MASK and change it from an > enumeration member into a #define such that its type can be changed > into unsigned long. That allows to write & ~RQ_STATE_MASK instead of > ~(unsigned long)RQ_STATE_MASK. > - Remove all request member variables that became superfluous due to > this change: gstate, gstate_seq and aborted_gstate_sync. > - Remove the request state information that became superfluous due to this > patch, namely RQF_MQ_TIMEOUT_EXPIRED. > - Remove the code that became superfluous due to this change, namely > the RCU lock and unlock statements in blk_mq_complete_request() and > also the synchronize_rcu() call in the timeout handler. Any chance you can try with the newer version? https://github.com/bvanassche/linux/commit/4acd555fa13087 -- Jens Axboe
