| Message ID | 20171031215808.11629-1-longli@exchange.microsoft.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On 10/31/2017 05:58 PM, Long Li wrote: > From: Long Li <longli@microsoft.com> > > When there are multiple disks attached to the same SCSI controller, > the host may send several VSTOR_OPERATION_REMOVE_DEVICE or > VSTOR_OPERATION_ENUMERATE_BUS messages in a row, to indicate there is a > change on the SCSI controller. In response, storvsc rescans the SCSI host. > > There is no need to do multiple scans on the same host. Fix the code to do > only one scan. > > Signed-off-by: Long Li <longli@microsoft.com> > --- > drivers/scsi/storvsc_drv.c | 26 +++++++++++--------------- > 1 file changed, 11 insertions(+), 15 deletions(-) > > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c > index 6febcdb..b602f52 100644 > --- a/drivers/scsi/storvsc_drv.c > +++ b/drivers/scsi/storvsc_drv.c > @@ -488,6 +488,8 @@ struct hv_host_device { > unsigned char target; > struct workqueue_struct *handle_error_wq; > char work_q_name[20]; > + struct work_struct host_scan_work; > + struct Scsi_Host *host; > }; > > struct storvsc_scan_work { > @@ -516,13 +518,12 @@ static void storvsc_device_scan(struct work_struct *work) > > static void storvsc_host_scan(struct work_struct *work) > { > - struct storvsc_scan_work *wrk; > struct Scsi_Host *host; > struct scsi_device *sdev; > + struct hv_host_device *host_device = > + container_of(work, struct hv_host_device, host_scan_work); > > - wrk = container_of(work, struct storvsc_scan_work, work); > - host = wrk->host; > - > + host = host_device->host; > /* > * Before scanning the host, first check to see if any of the > * currrently known devices have been hot removed. We issue a > @@ -542,8 +543,6 @@ static void storvsc_host_scan(struct work_struct *work) > * Now scan the host to discover LUNs that may have been added. > */ > scsi_scan_host(host); > - > - kfree(wrk); > } > > static void storvsc_remove_lun(struct work_struct *work) > @@ -1119,8 +1118,7 @@ static void storvsc_on_receive(struct storvsc_device *stor_device, > struct vstor_packet *vstor_packet, > struct storvsc_cmd_request *request) > { > - struct storvsc_scan_work *work; > - > + struct hv_host_device *host_dev; > switch (vstor_packet->operation) { > case VSTOR_OPERATION_COMPLETE_IO: > storvsc_on_io_completion(stor_device, vstor_packet, request); > @@ -1128,13 +1126,9 @@ static void storvsc_on_receive(struct storvsc_device *stor_device, > > case VSTOR_OPERATION_REMOVE_DEVICE: > case VSTOR_OPERATION_ENUMERATE_BUS: > - work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC); > - if (!work) > - return; > - > - INIT_WORK(&work->work, storvsc_host_scan); > - work->host = stor_device->host; > - schedule_work(&work->work); > + host_dev = shost_priv(stor_device->host); > + queue_work( > + host_dev->handle_error_wq, &host_dev->host_scan_work); > break; > > case VSTOR_OPERATION_FCHBA_DATA: > @@ -1747,6 +1741,7 @@ static int storvsc_probe(struct hv_device *device, > > host_dev->port = host->host_no; > host_dev->dev = device; > + host_dev->host = host; > > > stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL); > @@ -1815,6 +1810,7 @@ static int storvsc_probe(struct hv_device *device, > create_singlethread_workqueue(host_dev->work_q_name); > if (!host_dev->handle_error_wq) > goto err_out2; > + INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan); > /* Register the HBA and start the scsi bus scan */ > ret = scsi_add_host(host, &device->device); > if (ret != 0) I've tested this patch with both a multipath failover while running fio and taking hyperV snap shots while luns are being hot added and removed. Tested-by: Cathy Avery <cavery@redhat.com>
Long, > When there are multiple disks attached to the same SCSI controller, > the host may send several VSTOR_OPERATION_REMOVE_DEVICE or > VSTOR_OPERATION_ENUMERATE_BUS messages in a row, to indicate there is > a change on the SCSI controller. In response, storvsc rescans the SCSI > host. Applied to 4.15/scsi-queue with some fuzz. Please verify, thanks!
> From: Martin K. Petersen [mailto:martin.petersen@oracle.com] > Sent: Monday, November 6, 2017 7:40 PM > To: Long Li <longli@microsoft.com> > Cc: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang > <haiyangz@microsoft.com>; Stephen Hemminger > <sthemmin@microsoft.com>; James E . J . Bottomley > <JBottomley@odin.com>; Martin K . Petersen > <martin.petersen@oracle.com>; devel@linuxdriverproject.org; linux- > scsi@vger.kernel.org; linux-kernel@vger.kernel.org; Long Li > <longli@microsoft.com> > Subject: Re: [PATCH] storvsc: Avoid excessive host scan on controller change > > > Long, > > > When there are multiple disks attached to the same SCSI controller, > > the host may send several VSTOR_OPERATION_REMOVE_DEVICE or > > VSTOR_OPERATION_ENUMERATE_BUS messages in a row, to indicate > there is > > a change on the SCSI controller. In response, storvsc rescans the SCSI > > host. > > Applied to 4.15/scsi-queue with some fuzz. Please verify, thanks! Martin, thank you! All looking good. Long > > -- > Martin K. Petersen Oracle Linux Engineering
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 6febcdb..b602f52 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -488,6 +488,8 @@ struct hv_host_device { unsigned char target; struct workqueue_struct *handle_error_wq; char work_q_name[20]; + struct work_struct host_scan_work; + struct Scsi_Host *host; }; struct storvsc_scan_work { @@ -516,13 +518,12 @@ static void storvsc_device_scan(struct work_struct *work) static void storvsc_host_scan(struct work_struct *work) { - struct storvsc_scan_work *wrk; struct Scsi_Host *host; struct scsi_device *sdev; + struct hv_host_device *host_device = + container_of(work, struct hv_host_device, host_scan_work); - wrk = container_of(work, struct storvsc_scan_work, work); - host = wrk->host; - + host = host_device->host; /* * Before scanning the host, first check to see if any of the * currrently known devices have been hot removed. We issue a @@ -542,8 +543,6 @@ static void storvsc_host_scan(struct work_struct *work) * Now scan the host to discover LUNs that may have been added. */ scsi_scan_host(host); - - kfree(wrk); } static void storvsc_remove_lun(struct work_struct *work) @@ -1119,8 +1118,7 @@ static void storvsc_on_receive(struct storvsc_device *stor_device, struct vstor_packet *vstor_packet, struct storvsc_cmd_request *request) { - struct storvsc_scan_work *work; - + struct hv_host_device *host_dev; switch (vstor_packet->operation) { case VSTOR_OPERATION_COMPLETE_IO: storvsc_on_io_completion(stor_device, vstor_packet, request); @@ -1128,13 +1126,9 @@ static void storvsc_on_receive(struct storvsc_device *stor_device, case VSTOR_OPERATION_REMOVE_DEVICE: case VSTOR_OPERATION_ENUMERATE_BUS: - work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC); - if (!work) - return; - - INIT_WORK(&work->work, storvsc_host_scan); - work->host = stor_device->host; - schedule_work(&work->work); + host_dev = shost_priv(stor_device->host); + queue_work( + host_dev->handle_error_wq, &host_dev->host_scan_work); break; case VSTOR_OPERATION_FCHBA_DATA: @@ -1747,6 +1741,7 @@ static int storvsc_probe(struct hv_device *device, host_dev->port = host->host_no; host_dev->dev = device; + host_dev->host = host; stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL); @@ -1815,6 +1810,7 @@ static int storvsc_probe(struct hv_device *device, create_singlethread_workqueue(host_dev->work_q_name); if (!host_dev->handle_error_wq) goto err_out2; + INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan); /* Register the HBA and start the scsi bus scan */ ret = scsi_add_host(host, &device->device); if (ret != 0)