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scsi: core: Run queue in case of I/O resource contention failure

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I/O requests may be held in scheduler queue because of resource contention.
The starvation scenario was handled properly in the regular completion
path but we failed to account for it during I/O submission. This lead to
the hang captured below. Make sure we run the queue when resource
contention is encountered in the submission path.

[   39.054963] scsi 13:0:0:0: rejecting I/O to dead device
[   39.058700] scsi 13:0:0:0: rejecting I/O to dead device
[   39.087855] sd 13:0:0:1: [sdd] Synchronizing SCSI cache
[   39.088909] scsi 13:0:0:1: rejecting I/O to dead device
[   39.095351] scsi 13:0:0:1: rejecting I/O to dead device
[   39.096962] scsi 13:0:0:1: rejecting I/O to dead device
[  247.021859] INFO: task scsi-stress-rem:813 blocked for more than 122 seconds.
[  247.023258]       Not tainted 5.8.0-rc2 #8
[  247.024069] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  247.025331] scsi-stress-rem D    0   813    802 0x00004000
[  247.025334] Call Trace:
[  247.025354]  __schedule+0x504/0x55f
[  247.027987]  schedule+0x72/0xa8
[  247.027991]  blk_mq_freeze_queue_wait+0x63/0x8c
[  247.027994]  ? do_wait_intr_irq+0x7a/0x7a
[  247.027996]  blk_cleanup_queue+0x4b/0xc9
[  247.028000]  __scsi_remove_device+0xf6/0x14e
[  247.028002]  scsi_remove_device+0x21/0x2b
[  247.029037]  sdev_store_delete+0x58/0x7c
[  247.029041]  kernfs_fop_write+0x10d/0x14f
[  247.031281]  vfs_write+0xa2/0xdf
[  247.032670]  ksys_write+0x6b/0xb3
[  247.032673]  do_syscall_64+0x56/0x82
[  247.034053]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  247.034059] RIP: 0033:0x7f69f39e9008
[  247.036330] Code: Bad RIP value.
[  247.036331] RSP: 002b:00007ffdd8116498 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  247.037613] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f69f39e9008
[  247.039714] RDX: 0000000000000002 RSI: 000055cde92a0ab0 RDI: 0000000000000001
[  247.039715] RBP: 000055cde92a0ab0 R08: 000000000000000a R09: 00007f69f3a79e80
[  247.039716] R10: 000000000000000a R11: 0000000000000246 R12: 00007f69f3abb780
[  247.039717] R13: 0000000000000002 R14: 00007f69f3ab6740 R15: 0000000000000002

Link: https://lore.kernel.org/r/20200720025435.812030-1-ming.lei@redhat.com
Cc: linux-block@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Ming Lei 2020-07-20 10:54:35 +08:00 committed by Martin K. Petersen
parent 07d3f04550
commit 3f0dcfbcd2
1 changed files with 11 additions and 5 deletions
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16
drivers/scsi/scsi_lib.c
View File

@ -547,6 +547,15 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
scsi_uninit_cmd(cmd);
}
static void scsi_run_queue_async(struct scsi_device *sdev)
{
if (scsi_target(sdev)->single_lun ||
!list_empty(&sdev->host->starved_list))
kblockd_schedule_work(&sdev->requeue_work);
else
blk_mq_run_hw_queues(sdev->request_queue, true);
}
/* Returns false when no more bytes to process, true if there are more */
static bool scsi_end_request(struct request *req, blk_status_t error,
unsigned int bytes)
@ -591,11 +600,7 @@ static bool scsi_end_request(struct request *req, blk_status_t error,
__blk_mq_end_request(req, error);
if (scsi_target(sdev)->single_lun ||
!list_empty(&sdev->host->starved_list))
kblockd_schedule_work(&sdev->requeue_work);
else
blk_mq_run_hw_queues(q, true);
scsi_run_queue_async(sdev);
percpu_ref_put(&q->q_usage_counter);
return false;
@ -1702,6 +1707,7 @@ out_put_budget:
*/
if (req->rq_flags & RQF_DONTPREP)
scsi_mq_uninit_cmd(cmd);
scsi_run_queue_async(sdev);
break;
}
return ret;