| Message ID | 20180110181817.25166-5-bart.vanassche@wdc.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Wed, Jan 10, 2018 at 10:18:17AM -0800, Bart Van Assche wrote: > The previous two patches guarantee that srp_queuecommand() does not get > invoked while reconnecting occurs. Hence remove the code from > srp_queuecommand() that prevents command queueing while reconnecting. > This patch avoids that the following can appear in the kernel log: > > BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747 > in_atomic(): 1, irqs_disabled(): 0, pid: 5600, name: scsi_eh_9 > 1 lock held by scsi_eh_9/5600: > #0: (rcu_read_lock){....}, at: [<00000000cbb798c7>] __blk_mq_run_hw_queue+0xf1/0x1e0 > Preemption disabled at: > [<00000000139badf2>] __blk_mq_delay_run_hw_queue+0x78/0xf0 > CPU: 9 PID: 5600 Comm: scsi_eh_9 Tainted: G W 4.15.0-rc4-dbg+ #1 > Hardware name: Dell Inc. PowerEdge R720/0VWT90, BIOS 2.5.4 01/22/2016 > Call Trace: > dump_stack+0x67/0x99 > ___might_sleep+0x16a/0x250 [ib_srp] > __mutex_lock+0x46/0x9d0 > srp_queuecommand+0x356/0x420 [ib_srp] > scsi_dispatch_cmd+0xf6/0x3f0 > scsi_queue_rq+0x4a8/0x5f0 > blk_mq_dispatch_rq_list+0x73/0x440 > blk_mq_sched_dispatch_requests+0x109/0x1a0 > __blk_mq_run_hw_queue+0x131/0x1e0 > __blk_mq_delay_run_hw_queue+0x9a/0xf0 > blk_mq_run_hw_queue+0xc0/0x1e0 > blk_mq_start_hw_queues+0x2c/0x40 > scsi_run_queue+0x18e/0x2d0 > scsi_run_host_queues+0x22/0x40 > scsi_error_handler+0x18d/0x5f0 > kthread+0x11c/0x140 > ret_from_fork+0x24/0x30 > > Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> > Reviewed-by: Hannes Reinecke <hare@suse.com> > Cc: Jason Gunthorpe <jgg@mellanox.com> > Cc: Doug Ledford <dledford@redhat.com> > --- > drivers/infiniband/ulp/srp/ib_srp.c | 21 ++------------------- > 1 file changed, 2 insertions(+), 19 deletions(-) > > diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c > index 972d4b3c5223..670f187ecb91 100644 > --- a/drivers/infiniband/ulp/srp/ib_srp.c > +++ b/drivers/infiniband/ulp/srp/ib_srp.c > @@ -2149,7 +2149,6 @@ static void srp_handle_qp_err(struct ib_cq *cq, struct ib_wc *wc, > static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) > { > struct srp_target_port *target = host_to_target(shost); > - struct srp_rport *rport = target->rport; > struct srp_rdma_ch *ch; > struct srp_request *req; > struct srp_iu *iu; > @@ -2159,16 +2158,6 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) > u32 tag; > u16 idx; > int len, ret; > - const bool in_scsi_eh = !in_interrupt() && current == shost->ehandler; > - > - /* > - * The SCSI EH thread is the only context from which srp_queuecommand() > - * can get invoked for blocked devices (SDEV_BLOCK / > - * SDEV_CREATED_BLOCK). Avoid racing with srp_reconnect_rport() by > - * locking the rport mutex if invoked from inside the SCSI EH. > - */ > - if (in_scsi_eh) > - mutex_lock(&rport->mutex); This issue is triggered because that the above EH handler context detection is wrong since scsi_run_host_queues() from scsi_error_handler() is for handling normal requests, see the comment below: /* * finally we need to re-initiate requests that may be pending. we will * have had everything blocked while error handling is taking place, and * now that error recovery is done, we will need to ensure that these * requests are started. */ scsi_run_host_queues(shost); This issue should have been fixed by the following one line change simply: in_scsi_eh = !!scmd->eh_action;
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 972d4b3c5223..670f187ecb91 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -2149,7 +2149,6 @@ static void srp_handle_qp_err(struct ib_cq *cq, struct ib_wc *wc, static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) { struct srp_target_port *target = host_to_target(shost); - struct srp_rport *rport = target->rport; struct srp_rdma_ch *ch; struct srp_request *req; struct srp_iu *iu; @@ -2159,16 +2158,6 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) u32 tag; u16 idx; int len, ret; - const bool in_scsi_eh = !in_interrupt() && current == shost->ehandler; - - /* - * The SCSI EH thread is the only context from which srp_queuecommand() - * can get invoked for blocked devices (SDEV_BLOCK / - * SDEV_CREATED_BLOCK). Avoid racing with srp_reconnect_rport() by - * locking the rport mutex if invoked from inside the SCSI EH. - */ - if (in_scsi_eh) - mutex_lock(&rport->mutex); scmnd->result = srp_chkready(target->rport); if (unlikely(scmnd->result)) @@ -2230,13 +2219,7 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) goto err_unmap; } - ret = 0; - -unlock_rport: - if (in_scsi_eh) - mutex_unlock(&rport->mutex); - - return ret; + return 0; err_unmap: srp_unmap_data(scmnd, ch, req); @@ -2258,7 +2241,7 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) ret = SCSI_MLQUEUE_HOST_BUSY; } - goto unlock_rport; + return ret; } /*
The previous two patches guarantee that srp_queuecommand() does not get invoked while reconnecting occurs. Hence remove the code from srp_queuecommand() that prevents command queueing while reconnecting. This patch avoids that the following can appear in the kernel log: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747 in_atomic(): 1, irqs_disabled(): 0, pid: 5600, name: scsi_eh_9 1 lock held by scsi_eh_9/5600: #0: (rcu_read_lock){....}, at: [<00000000cbb798c7>] __blk_mq_run_hw_queue+0xf1/0x1e0 Preemption disabled at: [<00000000139badf2>] __blk_mq_delay_run_hw_queue+0x78/0xf0 CPU: 9 PID: 5600 Comm: scsi_eh_9 Tainted: G W 4.15.0-rc4-dbg+ #1 Hardware name: Dell Inc. PowerEdge R720/0VWT90, BIOS 2.5.4 01/22/2016 Call Trace: dump_stack+0x67/0x99 ___might_sleep+0x16a/0x250 [ib_srp] __mutex_lock+0x46/0x9d0 srp_queuecommand+0x356/0x420 [ib_srp] scsi_dispatch_cmd+0xf6/0x3f0 scsi_queue_rq+0x4a8/0x5f0 blk_mq_dispatch_rq_list+0x73/0x440 blk_mq_sched_dispatch_requests+0x109/0x1a0 __blk_mq_run_hw_queue+0x131/0x1e0 __blk_mq_delay_run_hw_queue+0x9a/0xf0 blk_mq_run_hw_queue+0xc0/0x1e0 blk_mq_start_hw_queues+0x2c/0x40 scsi_run_queue+0x18e/0x2d0 scsi_run_host_queues+0x22/0x40 scsi_error_handler+0x18d/0x5f0 kthread+0x11c/0x140 ret_from_fork+0x24/0x30 Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Doug Ledford <dledford@redhat.com> --- drivers/infiniband/ulp/srp/ib_srp.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-)