blk-mq: comment on races related with timeout handler
authorMing Lei <tom.leiming@gmail.com>
Mon, 27 Mar 2017 12:06:55 +0000 (20:06 +0800)
committerJens Axboe <axboe@fb.com>
Wed, 29 Mar 2017 14:03:42 +0000 (08:03 -0600)
commitd9d149a39690184f63d74e3425c1e90b1d7e67d6
tree11aa011fd37301c78c492322a2fbc5d1afbd75b0
parenta4ef8e566fd2b24606524425c3de5e235bd85428
blk-mq: comment on races related with timeout handler

This patch adds comment on two races related with
timeout handler:

- requeue from queue busy vs. timeout
- rq free & reallocation vs. timeout

Both the races themselves and current solution aren't
explicit enough, so add comments on them.

Cc: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
block/blk-mq.c