WSL2-Linux-Kernel/block
Ming Lei 2a5cf35cd6 block: fix single range discard merge
There are actually two kinds of discard merge:

- one is the normal discard merge, just like normal read/write request,
and call it single-range discard

- another is the multi-range discard, queue_max_discard_segments(rq->q) > 1

For the former case, queue_max_discard_segments(rq->q) is 1, and we
should handle this kind of discard merge like the normal read/write
request.

This patch fixes the following kernel panic issue[1], which is caused by
not removing the single-range discard request from elevator queue.

Guangwu has one raid discard test case, in which this issue is a bit
easier to trigger, and I verified that this patch can fix the kernel
panic issue in Guangwu's test case.

[1] kernel panic log from Jens's report

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000148
 PGD 0 P4D 0.
 Oops: 0000 [#1] SMP PTI
 CPU: 37 PID: 763 Comm: kworker/37:1H Not tainted \
4.20.0-rc3-00649-ge64d9a554a91-dirty #14  Hardware name: Wiwynn \
Leopard-Orv2/Leopard-DDR BW, BIOS LBM08   03/03/2017       Workqueue: kblockd \
blk_mq_run_work_fn                                            RIP: \
0010:blk_mq_get_driver_tag+0x81/0x120                                       Code: 24 \
10 48 89 7c 24 20 74 21 83 fa ff 0f 95 c0 48 8b 4c 24 28 65 48 33 0c 25 28 00 00 00 \
0f 85 96 00 00 00 48 83 c4 30 5b 5d c3 <48> 8b 87 48 01 00 00 8b 40 04 39 43 20 72 37 \
f6 87 b0 00 00 00 02  RSP: 0018:ffffc90004aabd30 EFLAGS: 00010246                     \
  RAX: 0000000000000003 RBX: ffff888465ea1300 RCX: ffffc90004aabde8
 RDX: 00000000ffffffff RSI: ffffc90004aabde8 RDI: 0000000000000000
 RBP: 0000000000000000 R08: ffff888465ea1348 R09: 0000000000000000
 R10: 0000000000001000 R11: 00000000ffffffff R12: ffff888465ea1300
 R13: 0000000000000000 R14: ffff888465ea1348 R15: ffff888465d10000
 FS:  0000000000000000(0000) GS:ffff88846f9c0000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000148 CR3: 000000000220a003 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  blk_mq_dispatch_rq_list+0xec/0x480
  ? elv_rb_del+0x11/0x30
  blk_mq_do_dispatch_sched+0x6e/0xf0
  blk_mq_sched_dispatch_requests+0xfa/0x170
  __blk_mq_run_hw_queue+0x5f/0xe0
  process_one_work+0x154/0x350
  worker_thread+0x46/0x3c0
  kthread+0xf5/0x130
  ? process_one_work+0x350/0x350
  ? kthread_destroy_worker+0x50/0x50
  ret_from_fork+0x1f/0x30
 Modules linked in: sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel \
kvm switchtec irqbypass iTCO_wdt iTCO_vendor_support efivars cdc_ether usbnet mii \
cdc_acm i2c_i801 lpc_ich mfd_core ipmi_si ipmi_devintf ipmi_msghandler acpi_cpufreq \
button sch_fq_codel nfsd nfs_acl lockd grace auth_rpcgss oid_registry sunrpc nvme \
nvme_core fuse sg loop efivarfs autofs4  CR2: 0000000000000148                        \

 ---[ end trace 340a1fb996df1b9b ]---
 RIP: 0010:blk_mq_get_driver_tag+0x81/0x120
 Code: 24 10 48 89 7c 24 20 74 21 83 fa ff 0f 95 c0 48 8b 4c 24 28 65 48 33 0c 25 28 \
00 00 00 0f 85 96 00 00 00 48 83 c4 30 5b 5d c3 <48> 8b 87 48 01 00 00 8b 40 04 39 43 \
20 72 37 f6 87 b0 00 00 00 02

Fixes: 445251d0f4 ("blk-mq: fix discard merge with scheduler attached")
Reported-by: Jens Axboe <axboe@kernel.dk>
Cc: Guangwu Zhang <guazhang@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-30 10:07:57 -07:00
..
partitions partitions/aix: append null character to print data from disk 2018-07-27 09:17:41 -06:00
Kconfig block: remove redundant 'default n' from Kconfig-s 2018-10-10 14:11:07 -06:00
Kconfig.iosched block: remove redundant 'default n' from Kconfig-s 2018-10-10 14:11:07 -06:00
Makefile block: Move power management code into a new source file 2018-09-26 15:11:28 -06:00
badblocks.c
bfq-cgroup.c blkcg: revert blkcg cleanups series 2018-11-01 19:59:53 -06:00
bfq-iosched.c blkcg: revert blkcg cleanups series 2018-11-01 19:59:53 -06:00
bfq-iosched.h block, bfq: improve asymmetric scenarios detection 2018-10-13 15:40:00 -06:00
bfq-wf2q.c block, bfq: fix asymmetric scenarios detection 2018-10-25 11:17:40 -06:00
bio-integrity.c block: remove bio_rewind_iter() 2018-09-06 15:12:24 -06:00
bio.c block: copy ioprio in __bio_clone_fast() and bounce 2018-11-12 10:35:25 -07:00
blk-cgroup.c blkcg: revert blkcg cleanups series 2018-11-01 19:59:53 -06:00
blk-core.c SCSI: fix queue cleanup race before queue initialization is done 2018-11-14 08:19:10 -07:00
blk-exec.c
blk-flush.c blk-mq: change gfp flags to GFP_NOIO in blk_mq_realloc_hw_ctxs 2018-10-13 15:42:01 -06:00
blk-integrity.c block: merge BIOVEC_SEG_BOUNDARY into biovec_phys_mergeable 2018-09-24 12:33:57 -06:00
blk-ioc.c block, mm: remove unnecessary __GFP_HIGH flag 2018-07-09 09:07:54 -06:00
blk-iolatency.c for-linus-20181102 2018-11-02 11:25:48 -07:00
blk-lib.c block: fix 32 bit overflow in __blkdev_issue_discard() 2018-11-14 08:17:18 -07:00
blk-map.c
blk-merge.c block: fix single range discard merge 2018-11-30 10:07:57 -07:00
blk-mq-cpumap.c
blk-mq-debugfs-zoned.c block: Make struct request_queue smaller for CONFIG_BLK_DEV_ZONED=n 2018-07-09 09:07:52 -06:00
blk-mq-debugfs.c block: add a report_zones method 2018-10-25 11:17:40 -06:00
blk-mq-debugfs.h block: Make struct request_queue smaller for CONFIG_BLK_DEV_ZONED=n 2018-07-09 09:07:52 -06:00
blk-mq-pci.c blk-mq: code clean-up by adding an API to clear set->mq_map 2018-07-09 09:07:53 -06:00
blk-mq-rdma.c
blk-mq-sched.c blk-mq: init hctx sched after update ctx and hctx mapping 2018-08-21 09:02:55 -06:00
blk-mq-sched.h block: move call of scheduler's ->completed_request() hook 2018-09-27 17:34:52 -06:00
blk-mq-sysfs.c
blk-mq-tag.c This is the 4.19-rc6 release 2018-10-01 08:58:57 -06:00
blk-mq-tag.h
blk-mq-virtio.c
blk-mq.c blk-mq: place trace_block_getrq() in correct place 2018-10-25 11:17:40 -06:00
blk-mq.h blk-mq: issue directly if hw queue isn't busy in case of 'none' 2018-07-17 16:04:00 -06:00
blk-pm.c blk-mq: Enable support for runtime power management 2018-09-26 15:11:29 -06:00
blk-pm.h block: Split blk_pm_add_request() and blk_pm_put_request() 2018-09-26 15:11:28 -06:00
blk-rq-qos.c blk-rq-qos: make depth comparisons unsigned 2018-07-22 11:30:53 -06:00
blk-rq-qos.h blk-rq-qos: make depth comparisons unsigned 2018-07-22 11:30:53 -06:00
blk-settings.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
blk-softirq.c blk-mq: complete req in softirq context in case of single queue 2018-10-08 10:50:43 -06:00
blk-stat.c block: export blk_stat_enable_accounting() 2018-09-27 17:34:54 -06:00
blk-stat.h blk-stat: export helpers for modifying blk_rq_stat 2018-07-09 09:07:54 -06:00
blk-sysfs.c block: call rq_qos_exit() after queue is frozen 2018-10-31 08:40:36 -06:00
blk-tag.c for-linus-20180616 2018-06-17 05:37:55 +09:00
blk-throttle.c blkcg: revert blkcg cleanups series 2018-11-01 19:59:53 -06:00
blk-timeout.c blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE 2018-06-23 10:25:45 -06:00
blk-wbt.c blk-wbt: wake up all when we scale up, not down 2018-10-11 13:31:28 -06:00
blk-wbt.h block: remove external dependency on wbt_flags 2018-07-09 09:07:54 -06:00
blk-zoned.c block: Introduce blk_revalidate_disk_zones() 2018-10-25 11:17:40 -06:00
blk.h block: make sure discard bio is aligned with logical block size 2018-11-09 06:23:14 -07:00
bounce.c block: copy ioprio in __bio_clone_fast() and bounce 2018-11-12 10:35:25 -07:00
bsg-lib.c block/bsg-lib: use PTR_ERR_OR_ZERO to simplify the flow path 2018-08-01 09:13:03 -06:00
bsg.c block: bsg: move atomic_t ref_count variable to refcount API 2018-08-27 19:17:02 -06:00
cfq-iosched.c blkcg: revert blkcg cleanups series 2018-11-01 19:59:53 -06:00
cmdline-parser.c
compat_ioctl.c
deadline-iosched.c
elevator.c This is the 4.19-rc6 release 2018-10-01 08:58:57 -06:00
genhd.c This is the 4.19-rc6 release 2018-10-01 08:58:57 -06:00
ioctl.c block: Introduce BLKGETNRZONES ioctl 2018-10-25 11:17:40 -06:00
ioprio.c
kyber-iosched.c kyber: fix integer overflow of latency targets on 32-bit 2018-09-28 10:49:39 -06:00
mq-deadline.c
noop-iosched.c
opal_proto.h
partition-generic.c block: use nanosecond resolution for iostat 2018-09-21 20:26:59 -06:00
scsi_ioctl.c
sed-opal.c block: sed-opal: Fix a couple off by one bugs 2018-06-20 12:04:06 -06:00
t10-pi.c block: move dif_prepare/dif_complete functions to block layer 2018-07-30 08:27:02 -06:00