Re: LTP case read_all_proc fails on qemux86-64 since 5.0-rc1
From: Jens Axboe
Date: Wed Jan 23 2019 - 11:05:24 EST
On 1/22/19 8:39 PM, Jens Axboe wrote:
> On Jan 22, 2019, at 8:13 PM, He Zhe <zhe.he@xxxxxxxxxxxxx> wrote:
>>
>>
>> LTP case read_all_proc(read_all -d /proc -q -r 10) often, but not every time, fails with the following call traces, since 600335205b8d "ide: convert to blk-mq"(5.0-rc1) till now(5.0-rc3).
>>
>> qemu-system-x86_64 -drive file=rootfs.ext4,if=virtio,format=raw -object rng-random,filename=/dev/urandom,id=rng0 -device virtio-rng-pci,rng=rng0 -nographic -m 16192 -smp cpus=12 -cpu core2duo -enable-kvm -serial mon:stdio -serial null -kernel bzImage -append 'root=/dev/vda rw highres=off console=ttyS0 mem=16192M'
>>
>> tst_test.c:1085: INFO: Timeout per run is 0h 05m 00s
>> [ 47.080156] Warning: /proc/ide/hd?/settings interface is obsolete, and will be removed soon!
>> [ 47.085330] ------------[ cut here ]------------
>> [ 47.085810] kernel BUG at block/blk-mq.c:767!
>> [ 47.086498] invalid opcode: 0000 [#1] PREEMPT SMP PTI
>> [ 47.087022] CPU: 5 PID: 146 Comm: kworker/5:1H Not tainted 5.0.0-rc3 #1
>> [ 47.087858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
>> [ 47.088992] Workqueue: kblockd blk_mq_run_work_fn
>> [ 47.089469] RIP: 0010:blk_mq_add_to_requeue_list+0xc1/0xd0
>> [ 47.090035] Code: 48 8d 53 48 49 8b 8c 24 b8 04 00 00 48 89 51 08 48 89 4b 48 49 8d 8c 24 b8 04 00 00 48 89 4b 50 49 89 94 24 b8 04 00 008
>> [ 47.091930] RSP: 0018:ffff9e1ea4b43e40 EFLAGS: 00010002
>> [ 47.092458] RAX: ffff9e1ea13c0048 RBX: ffff9e1ea13c0000 RCX: 0000000000000006
>> [ 47.093181] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9e1ea13c0000
>> [ 47.093906] RBP: ffff9e1ea4b43e68 R08: ffffeb5bcf630680 R09: 0000000000000000
>> [ 47.094626] R10: 0000000000000001 R11: 0000000000000012 R12: ffff9e1ea1033a40
>> [ 47.095347] R13: ffff9e1ea13a8d00 R14: ffff9e1ea13a9000 R15: 0000000000000046
>> [ 47.096071] FS: 0000000000000000(0000) GS:ffff9e1ea4b40000(0000) knlGS:0000000000000000
>> [ 47.096898] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 47.097477] CR2: 0000003fda41fda0 CR3: 00000003d8e6a000 CR4: 00000000000006e0
>> [ 47.098203] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> [ 47.098929] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> [ 47.099650] Call Trace:
>> [ 47.099910] <IRQ>
>> [ 47.100128] blk_mq_requeue_request+0x58/0x60
>> [ 47.100576] ide_requeue_and_plug+0x20/0x50
>> [ 47.101014] ide_intr+0x21a/0x230
>> [ 47.101362] ? idecd_open+0xc0/0xc0
>> [ 47.101735] __handle_irq_event_percpu+0x43/0x1e0
>> [ 47.102214] handle_irq_event_percpu+0x32/0x80
>> [ 47.102668] handle_irq_event+0x39/0x60
>> [ 47.103074] handle_edge_irq+0xe8/0x1c0
>> [ 47.103470] handle_irq+0x20/0x30
>> [ 47.103819] do_IRQ+0x46/0xe0
>> [ 47.104128] common_interrupt+0xf/0xf
>> [ 47.104505] </IRQ>
>> [ 47.104731] RIP: 0010:ide_output_data+0xbc/0x100
>> [ 47.105201] Code: 74 22 8d 41 ff 85 c9 74 24 49 8d 54 40 02 41 0f b7 00 66 41 89 01 49 83 c0 02 49 39 d0 75 ef 5b 41 5c 5d c3 4c 89 c6 445
>> [ 47.107092] RSP: 0018:ffffbd508059bb18 EFLAGS: 00010246 ORIG_RAX: ffffffffffffffdd
>> [ 47.107862] RAX: ffff9e1ea13a8800 RBX: ffff9e1ea13a9000 RCX: 0000000000000000
>> [ 47.108581] RDX: 0000000000000170 RSI: ffff9e1ea13c012c RDI: 0000000000000000
>> [ 47.109293] RBP: ffffbd508059bb28 R08: ffff9e1ea13c0120 R09: 0000000000000170
>> [ 47.110016] R10: 000000000000000d R11: 000000000000000c R12: ffff9e1ea13a8800
>> [ 47.110731] R13: 000000000000000c R14: ffff9e1ea13c0000 R15: 0000000000007530
>> [ 47.111446] ide_transfer_pc+0x216/0x310
>> [ 47.111848] ? __const_udelay+0x3d/0x40
>> [ 47.112236] ? ide_execute_command+0x85/0xb0
>> [ 47.112668] ? ide_pc_intr+0x3f0/0x3f0
>> [ 47.113051] ? ide_check_atapi_device+0x110/0x110
>> [ 47.113524] ide_issue_pc+0x178/0x240
>> [ 47.113901] ide_cd_do_request+0x15c/0x350
>> [ 47.114314] ide_queue_rq+0x180/0x6b0
>> [ 47.114686] ? blk_mq_get_driver_tag+0xa1/0x110
>> [ 47.115153] blk_mq_dispatch_rq_list+0x90/0x550
>> [ 47.115606] ? __queue_delayed_work+0x63/0x90
>> [ 47.116054] ? deadline_fifo_request+0x41/0x90
>> [ 47.116506] blk_mq_do_dispatch_sched+0x80/0x100
>> [ 47.116976] blk_mq_sched_dispatch_requests+0xfc/0x170
>> [ 47.117491] __blk_mq_run_hw_queue+0x6f/0xd0
>> [ 47.117941] blk_mq_run_work_fn+0x1b/0x20
>> [ 47.118342] process_one_work+0x14c/0x450
>> [ 47.118747] worker_thread+0x4a/0x440
>> [ 47.119125] kthread+0x105/0x140
>> [ 47.119456] ? process_one_work+0x450/0x450
>> [ 47.119880] ? kthread_park+0x90/0x90
>> [ 47.120251] ret_from_fork+0x35/0x40
>> [ 47.120619] Modules linked in:
>> [ 47.120952] ---[ end trace 4562f716e88fdefe ]---
>> [ 47.121423] RIP: 0010:blk_mq_add_to_requeue_list+0xc1/0xd0
>> [ 47.121981] Code: 48 8d 53 48 49 8b 8c 24 b8 04 00 00 48 89 51 08 48 89 4b 48 49 8d 8c 24 b8 04 00 00 48 89 4b 50 49 89 94 24 b8 04 00 008
>> [ 47.123851] RSP: 0018:ffff9e1ea4b43e40 EFLAGS: 00010002
>> [ 47.124393] RAX: ffff9e1ea13c0048 RBX: ffff9e1ea13c0000 RCX: 0000000000000006
>> [ 47.125108] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff9e1ea13c0000
>> [ 47.125819] RBP: ffff9e1ea4b43e68 R08: ffffeb5bcf630680 R09: 0000000000000000
>> [ 47.126539] R10: 0000000000000001 R11: 0000000000000012 R12: ffff9e1ea1033a40
>> [ 47.127262] R13: ffff9e1ea13a8d00 R14: ffff9e1ea13a9000 R15: 0000000000000046
>> [ 47.127988] FS: 0000000000000000(0000) GS:ffff9e1ea4b40000(0000) knlGS:0000000000000000
>> [ 47.128793] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 47.129385] CR2: 0000003fda41fda0 CR3: 00000003d8e6a000 CR4: 00000000000006e0
>> [ 47.130104] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> [ 47.130823] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> [ 47.131547] Kernel panic - not syncing: Fatal exception in interrupt
>> [ 47.132609] Kernel Offset: 0x7c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
>> [ 47.133679] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
>> [ 47.134432] ------------[ cut here ]-----------
>
> Iâll take a look at this, thanks for the report.
I can't reproduce this, unfortunately. But I'm guessing it might be related
to a race with the requeue and request handling in IDE. Can you try with
the below patch?
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 8445b484ae69..a10347a6505a 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -439,7 +439,7 @@ static inline void ide_unlock_host(struct ide_host *host)
}
}
-void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
+static void __ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
{
struct request_queue *q = drive->queue;
@@ -451,6 +451,16 @@ void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
blk_mq_delay_run_hw_queue(q->queue_hw_ctx[0], 3);
}
+void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
+{
+ ide_hwif_t *hwif = drive->hwif;
+ unsigned long flags;
+
+ spin_lock_irqsave(&hwif->lock, flags);
+ __ide_requeue_and_plug(drive, rq);
+ spin_unlock_irqrestore(&hwif->lock, flags);
+}
+
/*
* Issue a new request to a device.
*/
@@ -560,9 +570,9 @@ blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
}
} else {
plug_device:
+ __ide_requeue_and_plug(drive, rq);
spin_unlock_irq(&hwif->lock);
ide_unlock_host(host);
- ide_requeue_and_plug(drive, rq);
return BLK_STS_OK;
}
@@ -687,12 +697,14 @@ void ide_timer_expiry (struct timer_list *t)
plug_device = 1;
}
}
+
+ if (plug_device)
+ __ide_requeue_and_plug(drive, rq_in_flight);
+
spin_unlock_irqrestore(&hwif->lock, flags);
- if (plug_device) {
+ if (plug_device)
ide_unlock_host(hwif->host);
- ide_requeue_and_plug(drive, rq_in_flight);
- }
}
/**
--
Jens Axboe