linux/block
Ming Lei 0bca799b92 blk-mq: order getting budget and driver tag
This patch orders getting budget and driver tag by making sure to acquire
driver tag after budget is got, this way can help to avoid the following
race:

1) before dispatch request from scheduler queue, get one budget first, then
dequeue a request, call it request A.

2) in another IO path for dispatching request B which is from hctx->dispatch,
driver tag is got, then try to get budget in blk_mq_dispatch_rq_list(),
unfortunately the budget is held by request A.

3) meantime blk_mq_dispatch_rq_list() is called for dispatching request
A, and try to get driver tag first, unfortunately no driver tag is
available because the driver tag is held by request B

4) both two IO pathes can't move on, and IO stall is caused.

This issue can be observed when running dbench on USB storage.

This patch fixes this issue by always getting budget before getting
driver tag.

Cc: stable@vger.kernel.org
Fixes: de14829740 ("blk-mq: introduce .get_budget and .put_budget in blk_mq_ops")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-10 08:38:46 -06:00
..
partitions partitions/msdos: Unable to mount UFS 44bsd partitions 2018-01-10 09:12:16 -07:00
badblocks.c badblocks: fix wrong return value in badblocks_set if badblocks are disabled 2017-11-03 11:29:50 -07:00
bfq-cgroup.c block, bfq: put async queues for root bfq groups too 2018-01-09 08:45:25 -07:00
bfq-iosched.c block, bfq: lower-bound the estimated peak rate to 1 2018-03-26 10:18:27 -06:00
bfq-iosched.h block, bfq: lower-bound the estimated peak rate to 1 2018-03-26 10:18:27 -06:00
bfq-wf2q.c block, bfq: limit sectors served with interactive weight raising 2018-01-18 08:21:37 -07:00
bio-integrity.c block: Fix __bio_integrity_endio() documentation 2018-01-17 09:59:33 -07:00
bio.c Fix slab name "biovec-(1<<(21-12))" 2018-03-21 19:25:22 -06:00
blk-cgroup.c blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir() 2018-03-16 10:35:12 -06:00
blk-core.c for-4.17/block-20180402 2018-04-05 14:27:02 -07:00
blk-exec.c blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request 2018-01-17 09:49:21 -07:00
blk-flush.c blk-mq: don't allocate driver tag upfront for flush rq 2017-11-04 12:40:13 -06:00
blk-integrity.c block: switch bios to blk_status_t 2017-06-09 09:27:32 -06:00
blk-ioc.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-lib.c block: add bdev_read_only() checks to common helpers 2018-01-18 12:57:19 -07:00
blk-map.c Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block 2018-01-29 11:51:49 -08:00
blk-merge.c blk-mq: fix discard merge with scheduler attached 2018-02-01 14:01:02 -07:00
blk-mq-cpumap.c blk-mq: map queues to all present CPUs 2017-07-24 10:01:31 -06:00
blk-mq-debugfs.c blk-mq-debugfs: Show more request state information 2018-03-17 14:41:17 -06:00
blk-mq-debugfs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-mq-pci.c blk-mq: Allow PCI vector offset for mapping queues 2018-03-27 21:25:36 -06:00
blk-mq-rdma.c block: Add rdma affinity based queue mapping helper 2017-08-08 14:58:03 -04:00
blk-mq-sched.c blk-mq-sched: Enable merging discard bio into request 2018-02-01 14:45:11 -07:00
blk-mq-sched.h blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request 2018-01-17 09:49:21 -07:00
blk-mq-sysfs.c block: properly protect the 'queue' kobj in blk_unregister_queue 2018-01-15 08:41:38 -07:00
blk-mq-tag.c blk-mq: improve heavily contended tag case 2017-12-22 11:09:37 -07:00
blk-mq-tag.h Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block 2017-11-14 15:32:19 -08:00
blk-mq-virtio.c
blk-mq.c blk-mq: order getting budget and driver tag 2018-04-10 08:38:46 -06:00
blk-mq.h blk-mq: Rename blk_mq_request_direct_issue() into blk_mq_request_issue_directly() 2018-01-19 12:51:59 -07:00
blk-settings.c block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}() 2018-03-08 14:13:48 -07:00
blk-softirq.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-stat.c block: Protect queue flag changes with the queue lock 2018-03-08 14:13:48 -07:00
blk-stat.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-sysfs.c block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}() 2018-03-08 14:13:48 -07:00
blk-tag.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-throttle.c Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block 2018-01-29 11:51:49 -08:00
blk-timeout.c blk-mq: Directly schedule q->timeout_work when aborting a request 2018-04-02 16:36:13 -06:00
blk-wbt.c blk-wbt: account flush requests correctly 2018-02-06 14:14:03 -07:00
blk-wbt.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-zoned.c block: Suppress kernel-doc warnings triggered by blk-zoned.c 2018-03-09 08:23:32 -07:00
blk.h block: Move the queue_flag_*() functions from a public into a private header file 2018-03-08 14:13:48 -07:00
bounce.c treewide: simplify Kconfig dependencies for removed archs 2018-03-26 15:55:57 +02:00
bsg-lib.c bsg: split handling of SCSI CDBs vs transport requeues 2018-03-13 11:40:24 -06:00
bsg.c bsg: split handling of SCSI CDBs vs transport requeues 2018-03-13 11:40:24 -06:00
cfq-iosched.c block/cfq: cache rightmost rb_node 2017-09-08 18:26:49 -07:00
cmdline-parser.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_ioctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
deadline-iosched.c deadline-iosched: Introduce zone locking support 2018-01-05 09:22:17 -07:00
elevator.c block: Document scheduler modification locking requirements 2018-01-18 12:54:42 -07:00
genhd.c block, char_dev: Use correct format specifier for unsigned ints 2018-03-15 17:59:24 +01:00
ioctl.c block: pass inclusive 'lend' parameter to truncate_inode_pages_range 2018-02-23 15:20:19 -07:00
ioprio.c block: Add fallthrough markers to switch statements 2017-06-21 11:46:07 -06:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig.iosched License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kyber-iosched.c block: kyber: fix domain token leak during requeue 2018-02-24 15:55:54 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mq-deadline.c mq-deadline: Make sure to always unlock zones 2018-03-01 08:39:24 -07:00
noop-iosched.c
opal_proto.h block: sed-opal: Set MBRDone on S3 resume path if TPER is MBREnabled 2017-09-11 09:45:52 -06:00
partition-generic.c block: display the correct diskname for bio 2018-03-01 08:41:25 -07:00
scsi_ioctl.c block: silently forbid sending any ioctl to a partition 2018-01-10 12:30:37 -07:00
sed-opal.c for-4.17/block-20180402 2018-04-05 14:27:02 -07:00
t10-pi.c t10-pi: Move opencoded contants to common header 2017-07-03 16:56:25 -06:00