linux/block
Yufen Yu d3b3859687 blk-mq: run queue no matter whether the request is the last request
We do test on a virtio scsi device (/dev/sda) and the default mq
scheduler is 'none'. We found a IO hung as following:

blk_finish_plug
  blk_mq_plug_issue_direct
      scsi_mq_get_budget
      //get budget_token fail and sdev->restarts=1

			     	 scsi_end_request
				   scsi_run_queue_async
                                   //sdev->restart=0 and run queue

     blk_mq_request_bypass_insert
        //add request to hctx->dispatch list

  //continue to dispath plug list
  blk_mq_dispatch_plug_list
      blk_mq_try_issue_list_directly
        //success issue all requests from plug list

After .get_budget fail, scsi_mq_get_budget will increase 'restarts'.
Normally, it will run hw queue when io complete and set 'restarts'
as 0. But if we run queue before adding request to the dispatch list
and blk_mq_dispatch_plug_list also success issue all requests, then
on one will run queue, and the request will be stall in the dispatch
list and cannot complete forever.

It is wrong to use last request of plug list to decide if run queue is
needed since all the remained requests in plug list may be from other
hctxs. To fix the bug, pass run_queue as true always to
blk_mq_request_bypass_insert().

Fix-suggested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Fixes: dc5fc361d8 ("block: attempt direct issue of plug list")
Link: https://lore.kernel.org/r/20220803023355.3687360-1-yuyufen@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-18 07:39:01 -06:00
..
partitions Folio changes for 6.0 2022-08-03 10:35:43 -07:00
badblocks.c block/badblocks: Remove redundant assignments 2022-04-23 07:15:26 -06:00
bdev.c block: stop using bdevname in bdev_write_inode 2022-07-14 10:27:56 -06:00
bfq-cgroup.c block/bfq: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
bfq-iosched.c block/bfq: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
bfq-iosched.h block/bfq: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
bfq-wf2q.c block: bfq: Fix kernel-doc headers 2022-06-27 06:29:12 -06:00
bio-integrity.c block: pass struct queue_limits to the bio splitting helpers 2022-08-02 21:08:53 -06:00
bio.c block: fix leaking page ref on truncated direct io 2022-08-02 21:08:54 -06:00
blk-cgroup-fc-appid.c blk-cgroup: move blkcg_{get,set}_fc_appid out of line 2022-05-02 14:06:20 -06:00
blk-cgroup-rwstat.c blk-cgroup: Fix the recursive blkg rwstat 2021-03-05 11:32:15 -07:00
blk-cgroup-rwstat.h block: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
blk-cgroup.c blk-cgroup: Use atomic{,64}_try_cmpxchg 2022-07-12 15:46:03 -06:00
blk-cgroup.h blk-cgroup: Use atomic{,64}_try_cmpxchg 2022-07-12 15:46:03 -06:00
blk-core.c block: move ->bio_split to the gendisk 2022-08-02 21:08:49 -06:00
blk-crypto-fallback.c block: remove superfluous calls to blkcg_bio_issue_init 2022-05-04 18:29:52 -06:00
blk-crypto-internal.h blk-crypto: show crypto capabilities in sysfs 2022-02-28 06:40:23 -07:00
blk-crypto-profile.c blk-crypto: remove blk_crypto_unregister() 2021-11-29 06:38:51 -07:00
blk-crypto-sysfs.c blk-crypto: show crypto capabilities in sysfs 2022-02-28 06:40:23 -07:00
blk-crypto.c blk-crypto: show crypto capabilities in sysfs 2022-02-28 06:40:23 -07:00
blk-flush.c block: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
blk-ia-ranges.c block: simplify disk_set_independent_access_ranges 2022-06-29 08:36:46 -06:00
blk-integrity.c blk-crypto: remove blk_crypto_unregister() 2021-11-29 06:38:51 -07:00
blk-ioc.c block: fix default IO priority handling again 2022-06-27 06:29:12 -06:00
blk-iocost.c block: don't allow the same type rq_qos add more than once 2022-07-20 06:44:14 -06:00
blk-iolatency.c block: don't allow the same type rq_qos add more than once 2022-07-20 06:44:14 -06:00
blk-ioprio.c blk-ioprio: Convert from rqos policy to direct call 2022-06-27 06:29:12 -06:00
blk-ioprio.h blk-ioprio: Convert from rqos policy to direct call 2022-06-27 06:29:12 -06:00
blk-lib.c block: stop using bdevname in __blkdev_issue_discard 2022-07-14 10:27:56 -06:00
blk-map.c block/blk-map: Remove redundant assignment 2022-04-23 07:15:26 -06:00
blk-merge.c block: pass struct queue_limits to the bio splitting helpers 2022-08-02 21:08:53 -06:00
blk-mq-cpumap.c blk-mq: remove the calling of local_memory_node() 2020-10-20 07:08:17 -06:00
blk-mq-debugfs-zoned.c block: move zone related fields to struct gendisk 2022-07-06 06:46:26 -06:00
blk-mq-debugfs.c block: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
blk-mq-debugfs.h block: remove per-disk debugfs files in blk_unregister_queue 2022-06-17 07:31:05 -06:00
blk-mq-pci.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-rdma.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-sched.c block: serialize all debugfs operations using q->debugfs_mutex 2022-06-17 07:31:05 -06:00
blk-mq-sched.h block: move blk_mq_sched_assign_ioc to blk-ioc.c 2021-11-29 06:41:29 -07:00
blk-mq-sysfs.c blk-mq: cleanup disk sysfs registration 2022-06-28 11:32:42 -06:00
blk-mq-tag.c blk-mq: Drop local variable for reserved tag 2022-07-06 06:33:53 -06:00
blk-mq-tag.h blk-mq: blk_mq_tag_busy is no need to return a value 2022-06-27 06:29:12 -06:00
blk-mq-virtio.c blk-mq: Fix typo in comment 2020-03-17 20:55:21 +01:00
blk-mq.c blk-mq: run queue no matter whether the request is the last request 2022-08-18 07:39:01 -06:00
blk-mq.h block: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
blk-pm.c scsi: block: pm: Always set request queue runtime active in blk_post_runtime_resume() 2021-12-22 23:38:29 -05:00
blk-pm.h block: Remove unused blk_pm_*() function definitions 2021-02-22 06:33:48 -07:00
blk-rq-qos.c block/rq_qos: Use atomic_try_cmpxchg in atomic_inc_below 2022-07-12 14:38:52 -06:00
blk-rq-qos.h block: don't allow the same type rq_qos add more than once 2022-07-20 06:44:14 -06:00
blk-settings.c block: pass a gendisk to blk_queue_clear_zone_settings 2022-07-06 06:46:26 -06:00
blk-stat.c block: make queue stat accounting a reference 2021-12-14 17:23:05 -07:00
blk-stat.h block: make queue stat accounting a reference 2021-12-14 17:23:05 -07:00
blk-sysfs.c block: move ->bio_split to the gendisk 2022-08-02 21:08:49 -06:00
blk-throttle.c block: Use enum req_op where appropriate 2022-07-14 12:14:30 -06:00
blk-throttle.h block: cancel all throttled bios in del_gendisk() 2022-03-18 09:57:56 -06:00
blk-timeout.c block: blk-timeout: delete duplicated word 2020-07-31 16:29:47 -06:00
blk-wbt.c block: don't allow the same type rq_qos add more than once 2022-07-20 06:44:14 -06:00
blk-wbt.h blk-wbt: remove wbt_track stub 2022-03-31 12:58:38 -06:00
blk-zoned.c treewide: Rename enum req_opf into enum req_op 2022-07-14 12:14:30 -06:00
blk.h block: pass struct queue_limits to the bio splitting helpers 2022-08-02 21:08:53 -06:00
bounce.c block: change the blk_queue_bounce calling convention 2022-08-02 17:22:54 -06:00
bsg-lib.c blk-mq: Drop blk_mq_ops.timeout 'reserved' arg 2022-07-06 06:33:53 -06:00
bsg.c scsi: core: bsg: Remove usage of the deprecated ida_simple_xxx() API 2022-06-21 21:22:51 -04:00
disk-events.c block: remove genhd.h 2022-02-02 07:49:59 -07:00
elevator.c for-5.18/block-2022-03-18 2022-03-21 16:48:55 -07:00
elevator.h block: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
fops.c iov_iter work, part 1 - isolated cleanups and optimizations. 2022-08-03 13:50:22 -07:00
genhd.c block: Do not call blk_put_queue() if gendisk allocation fails 2022-08-12 06:42:06 -06:00
holder.c block: remove WARN_ON() from bd_link_disk_holder 2022-06-23 07:48:05 -06:00
ioctl.c block: replace blkdev_nr_zones with bdev_nr_zones 2022-07-06 06:46:26 -06:00
ioprio.c block: Fix handling of tasks without ioprio in ioprio_get(2) 2022-06-27 06:29:12 -06:00
Kconfig block: remove "select BLK_RQ_IO_DATA_LEN" from BLK_CGROUP_IOCOST dependency 2022-06-29 08:35:57 -06:00
Kconfig.iosched block: only build the icq tracking code when needed 2021-12-16 10:59:02 -07:00
kyber-iosched.c block/kyber: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
Makefile blk-cgroup: move blkcg_{get,set}_fc_appid out of line 2022-05-02 14:06:20 -06:00
mq-deadline.c block/mq-deadline: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
opal_proto.h block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
sed-opal.c block: remove genhd.h 2022-02-02 07:49:59 -07:00
t10-pi.c block: add pi for extended integrity 2022-03-07 12:48:35 -07:00