diff options
| author | Tyrel Datwyler <tyreld@linux.vnet.ibm.com> | 2019-05-03 02:50:58 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2019-06-19 01:46:22 +0200 |
| commit | aa343c695aa59f03f31a2f989b8c977a727e46e3 (patch) | |
| tree | c1185d4850dd3bed1e43607d53d8d0d845d49fb0 /drivers/scsi/ibmvscsi | |
| parent | scsi: ibmvscsi: redo driver work thread to use enum action states (diff) | |
| download | linux-aa343c695aa59f03f31a2f989b8c977a727e46e3.tar.xz linux-aa343c695aa59f03f31a2f989b8c977a727e46e3.zip | |
scsi: ibmvscsi: fix tripping of blk_mq_run_hw_queue WARN_ON
After a successful SRP login response we call scsi_unblock_requests() to
kick any pending IOs. The callback to process this SRP response happens in
a tasklet and therefore is in softirq context. The result of such is that
when blk-mq is enabled, it is no longer safe to call scsi_unblock_requests()
from this context. The result of duing so triggers the following WARN_ON
splat in dmesg after a host reset or CRQ reenablement.
WARNING: CPU: 0 PID: 0 at block/blk-mq.c:1375 __blk_mq_run_hw_queue+0x120/0x180
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.0.0-rc8 #4
NIP [c0000000009771e0] __blk_mq_run_hw_queue+0x120/0x180
LR [c000000000977484] __blk_mq_delay_run_hw_queue+0x244/0x250
Call Trace:
__blk_mq_delay_run_hw_queue+0x244/0x250
blk_mq_run_hw_queue+0x8c/0x1c0
blk_mq_run_hw_queues+0x60/0x90
scsi_run_queue+0x1e4/0x3b0
scsi_run_host_queues+0x48/0x80
login_rsp+0xb0/0x100
ibmvscsi_handle_crq+0x30c/0x3e0
ibmvscsi_task+0x54/0xe0
tasklet_action_common.isra.3+0xc4/0x1a0
__do_softirq+0x174/0x3f4
irq_exit+0xf0/0x120
__do_irq+0xb0/0x210
call_do_irq+0x14/0x24
do_IRQ+0x9c/0x130
hardware_interrupt_common+0x14c/0x150
This patch fixes the issue by introducing a new host action for unblocking
the scsi requests in our seperate work thread.
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/ibmvscsi')
| -rw-r--r-- | drivers/scsi/ibmvscsi/ibmvscsi.c | 5 | ||||
| -rw-r--r-- | drivers/scsi/ibmvscsi/ibmvscsi.h | 1 |
2 files changed, 5 insertions, 1 deletions
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c index 8df82c58e7b9..727c31dc11a0 100644 --- a/drivers/scsi/ibmvscsi/ibmvscsi.c +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c @@ -1179,7 +1179,8 @@ static void login_rsp(struct srp_event_struct *evt_struct) be32_to_cpu(evt_struct->xfer_iu->srp.login_rsp.req_lim_delta)); /* If we had any pending I/Os, kick them */ - scsi_unblock_requests(hostdata->host); + hostdata->action = IBMVSCSI_HOST_ACTION_UNBLOCK; + wake_up(&hostdata->work_wait_q); } /** @@ -2123,6 +2124,7 @@ static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata) spin_lock_irqsave(hostdata->host->host_lock, flags); switch (hostdata->action) { case IBMVSCSI_HOST_ACTION_NONE: + case IBMVSCSI_HOST_ACTION_UNBLOCK: break; case IBMVSCSI_HOST_ACTION_RESET: spin_unlock_irqrestore(hostdata->host->host_lock, flags); @@ -2164,6 +2166,7 @@ static int __ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata) return 0; case IBMVSCSI_HOST_ACTION_RESET: case IBMVSCSI_HOST_ACTION_REENABLE: + case IBMVSCSI_HOST_ACTION_UNBLOCK: default: break; } diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.h b/drivers/scsi/ibmvscsi/ibmvscsi.h index 04bcbc832dc9..d9bf502334ba 100644 --- a/drivers/scsi/ibmvscsi/ibmvscsi.h +++ b/drivers/scsi/ibmvscsi/ibmvscsi.h @@ -92,6 +92,7 @@ enum ibmvscsi_host_action { IBMVSCSI_HOST_ACTION_NONE = 0, IBMVSCSI_HOST_ACTION_RESET, IBMVSCSI_HOST_ACTION_REENABLE, + IBMVSCSI_HOST_ACTION_UNBLOCK, }; /* all driver data associated with a host adapter */ |