acrn-kernel/block
Ross Lagerwall 557ea2ff05 blk-mq: Fix stall due to recursive flush plug
[ Upstream commit 7090426351 ]

We have seen rare IO stalls as follows:

* blk_mq_plug_issue_direct() is entered with an mq_list containing two
requests.
* For the first request, it sets last == false and enters the driver's
queue_rq callback.
* The driver queue_rq callback indirectly calls schedule() which calls
blk_flush_plug(). This may happen if the driver has the
BLK_MQ_F_BLOCKING flag set and is allowed to sleep in ->queue_rq.
* blk_flush_plug() handles the remaining request in the mq_list. mq_list
is now empty.
* The original call to queue_rq resumes (with last == false).
* The loop in blk_mq_plug_issue_direct() terminates because there are no
remaining requests in mq_list.

The IO is now stalled because the last request submitted to the driver
had last == false and there was no subsequent call to commit_rqs().

Fix this by returning early in blk_mq_flush_plug_list() if rq_count is 0
which it will be in the recursive case, rather than checking if the
mq_list is empty. At the same time, adjust one of the callers to skip
the mq_list empty check as it is not necessary.

Fixes: dc5fc361d8 ("block: attempt direct issue of plug list")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230714101106.3635611-1-ross.lagerwall@citrix.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-03 10:23:48 +02:00
..
partitions block/partition: fix signedness issue for Amiga partitions 2023-07-19 16:22:17 +02:00
Kconfig block: remove "select BLK_RQ_IO_DATA_LEN" from BLK_CGROUP_IOCOST dependency 2022-06-29 08:35:57 -06:00
Kconfig.iosched
Makefile blk-cgroup: move blkcg_{get,set}_fc_appid out of line 2022-05-02 14:06:20 -06:00
badblocks.c block/badblocks: Remove redundant assignments 2022-04-23 07:15:26 -06:00
bdev.c vfs: support STATX_DIOALIGN on block devices 2022-09-11 19:47:12 -05:00
bfq-cgroup.c block, bfq: fix uaf for bfqq in bic_set_bfqq() 2023-02-09 11:28:06 +01:00
bfq-iosched.c block, bfq: Fix division by zero error on zero wsum 2023-05-24 17:32:38 +01:00
bfq-iosched.h block, bfq: remove unused variable for bfq_queue 2022-10-20 05:46:49 -07:00
bfq-wf2q.c block, bfq: remove useless parameter for bfq_add/del_bfqq_busy() 2022-08-22 10:07:56 -06:00
bio-integrity.c block: bio-integrity: Copy flags when bio_integrity_payload is cloned 2023-03-10 09:32:46 +01:00
bio.c block: clear bio->bi_bdev when putting a bio back in the cache 2023-03-10 09:34:02 +01:00
blk-cgroup-fc-appid.c cgroup: Homogenize cgroup_get_from_id() return value 2022-08-26 10:57:41 -10:00
blk-cgroup-rwstat.c
blk-cgroup-rwstat.h block: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
blk-cgroup.c block: Skip destroyed blkg when restart in blkg_destroy_all() 2023-05-17 11:53:33 +02:00
blk-cgroup.h blk-cgroup: pass a gendisk to blkcg_init_queue and blkcg_exit_queue 2022-09-26 19:09:31 -06:00
blk-core.c blk-mq: Fix stall due to recursive flush plug 2023-08-03 10:23:48 +02:00
blk-crypto-fallback.c treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
blk-crypto-internal.h blk-mq: release crypto keyslot before reporting I/O complete 2023-05-11 23:03:00 +09:00
blk-crypto-profile.c blk-crypto: use dynamic lock class for blk_crypto_profile::lock 2023-07-23 13:49:21 +02:00
blk-crypto-sysfs.c
blk-crypto.c blk-crypto: make blk_crypto_evict_key() more robust 2023-05-11 23:03:01 +09:00
blk-flush.c block: change request end_io handler to pass back a return value 2022-09-30 07:49:09 -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-ioc.c block: fix default IO priority handling again 2022-06-27 06:29:12 -06:00
blk-iocost.c blk-iocost: use spin_lock_irqsave in adjust_inuse_and_calc_cost 2023-07-19 16:20:55 +02:00
blk-iolatency.c blk-cgroup: pass a gendisk to blkcg_schedule_throttle 2022-09-26 19:17:28 -06:00
blk-ioprio.c blk-ioprio: pass a gendisk to blk_ioprio_init and blk_ioprio_exit 2022-09-26 19:09:31 -06:00
blk-ioprio.h blk-ioprio: pass a gendisk to blk_ioprio_init and blk_ioprio_exit 2022-09-26 19:09:31 -06:00
blk-lib.c blk-lib: fix blkdev_issue_secure_erase 2022-09-15 00:25:17 -06:00
blk-map.c block: fix bio-cache for passthru IO 2023-06-05 09:26:21 +02:00
blk-merge.c blk-mq: release crypto keyslot before reporting I/O complete 2023-05-11 23:03:00 +09:00
blk-mq-cpumap.c block: Change the return type of blk_mq_map_queues() into void 2022-08-22 10:07:53 -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 blk-mq: fix potential io hang by wrong 'wake_batch' 2023-07-19 16:20:55 +02:00
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: Change the return type of blk_mq_map_queues() into void 2022-08-22 10:07:53 -06:00
blk-mq-rdma.c block: Change the return type of blk_mq_map_queues() into void 2022-08-22 10:07:53 -06:00
blk-mq-sched.c blk-mq: correct stale comment of .get_budget 2023-03-10 09:32:44 +01:00
blk-mq-sched.h
blk-mq-sysfs.c blk-mq: fix possible memleak when register 'hctx' failed 2022-12-31 13:33:03 +01:00
blk-mq-tag.c blk-mq: fix potential io hang by wrong 'wake_batch' 2023-07-19 16:20:55 +02:00
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 block: Change the return type of blk_mq_map_queues() into void 2022-08-22 10:07:53 -06:00
blk-mq.c blk-mq: Fix stall due to recursive flush plug 2023-08-03 10:23:48 +02:00
blk-mq.h blk-mq: fix potential io hang by wrong 'wake_batch' 2023-07-19 16:20:55 +02:00
blk-pm.c
blk-pm.h
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/blk-rq-qos: delete useless enmu RQ_QOS_IOPRIO 2022-09-21 19:50:53 -06:00
blk-settings.c block: fix revalidate performance regression 2023-06-09 10:34:23 +02:00
blk-stat.c blk-stat: fix QUEUE_FLAG_STATS clear 2023-05-11 23:03:00 +09:00
blk-stat.h
blk-sysfs.c blk-throttle: pass a gendisk to blk_throtl_register_queue 2022-09-26 19:17:27 -06:00
blk-throttle.c blk-throttle: Fix that bps of child could exceed bps limited in parent 2023-04-13 16:55:37 +02:00
blk-throttle.h blk-throttle: pass a gendisk to blk_throtl_cancel_bios 2022-09-26 19:17:28 -06:00
blk-timeout.c
blk-wbt.c blk-wbt: fix that 'rwb->wc' is always set to 1 in wbt_init() 2022-10-09 07:48:16 -06:00
blk-wbt.h blk-wbt: remove wbt_track stub 2022-03-31 12:58:38 -06:00
blk-zoned.c block: adapt blk_mq_plug() to not plug for writes that require a zone lock 2022-09-29 07:45:47 -06:00
blk.h block: Revert "block: Do not reread partition table on exclusively open device" 2023-03-17 08:50:20 +01:00
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: increment diskseq on all media change events 2023-07-19 16:21:47 +02:00
elevator.c blk-mq: use quiesced elevator switch when reinitializing queues 2022-09-27 09:58:56 -06:00
elevator.h block: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
fops.c block: Deny writable memory mapping if block is read-only 2023-06-09 10:34:17 +02:00
genhd.c block: fix blktrace debugfs entries leakage 2023-07-19 16:20:58 +02:00
holder.c block: remove WARN_ON() from bd_link_disk_holder 2022-06-23 07:48:05 -06:00
ioctl.c block: fix scan partition for exclusively open device again 2023-03-17 08:50:21 +01:00
ioprio.c block: Fix handling of tasks without ioprio in ioprio_get(2) 2022-06-27 06:29:12 -06:00
kyber-iosched.c block/kyber: Use the new blk_opf_t type 2022-07-14 12:14:30 -06:00
mq-deadline.c block: mq-deadline: Rename deadline_is_seq_writes() 2023-01-24 07:24:44 +01:00
opal_proto.h block: sed-opal: Add ioctl to return device status 2022-08-22 07:52:51 -06:00
sed-opal.c block: sed-opal: kmalloc the cmd/resp buffers 2022-11-08 07:14:35 -07:00
t10-pi.c