mirror of https://gitee.com/openkylin/linux.git
2a5cf35cd6
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:
|
||
|---|---|---|
| .. | ||
| partitions | ||
| Kconfig | ||
| Kconfig.iosched | ||
| Makefile | ||
| badblocks.c | ||
| bfq-cgroup.c | ||
| bfq-iosched.c | ||
| bfq-iosched.h | ||
| bfq-wf2q.c | ||
| bio-integrity.c | ||
| bio.c | ||
| blk-cgroup.c | ||
| blk-core.c | ||
| blk-exec.c | ||
| blk-flush.c | ||
| blk-integrity.c | ||
| blk-ioc.c | ||
| blk-iolatency.c | ||
| blk-lib.c | ||
| blk-map.c | ||
| blk-merge.c | ||
| blk-mq-cpumap.c | ||
| blk-mq-debugfs-zoned.c | ||
| blk-mq-debugfs.c | ||
| blk-mq-debugfs.h | ||
| blk-mq-pci.c | ||
| blk-mq-rdma.c | ||
| blk-mq-sched.c | ||
| blk-mq-sched.h | ||
| blk-mq-sysfs.c | ||
| blk-mq-tag.c | ||
| blk-mq-tag.h | ||
| blk-mq-virtio.c | ||
| blk-mq.c | ||
| blk-mq.h | ||
| blk-pm.c | ||
| blk-pm.h | ||
| blk-rq-qos.c | ||
| blk-rq-qos.h | ||
| blk-settings.c | ||
| blk-softirq.c | ||
| blk-stat.c | ||
| blk-stat.h | ||
| blk-sysfs.c | ||
| blk-tag.c | ||
| blk-throttle.c | ||
| blk-timeout.c | ||
| blk-wbt.c | ||
| blk-wbt.h | ||
| blk-zoned.c | ||
| blk.h | ||
| bounce.c | ||
| bsg-lib.c | ||
| bsg.c | ||
| cfq-iosched.c | ||
| cmdline-parser.c | ||
| compat_ioctl.c | ||
| deadline-iosched.c | ||
| elevator.c | ||
| genhd.c | ||
| ioctl.c | ||
| ioprio.c | ||
| kyber-iosched.c | ||
| mq-deadline.c | ||
| noop-iosched.c | ||
| opal_proto.h | ||
| partition-generic.c | ||
| scsi_ioctl.c | ||
| sed-opal.c | ||
| t10-pi.c | ||