From: KY Srinivasan <kys@microsoft.com>
To: Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@infradead.org>
CC: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "devel@linuxdriverproject.org" <devel@linuxdriverproject.org>,
        "ohering@suse.com" <ohering@suse.com>,
        "jbottomley@parallels.com" <jbottomley@parallels.com>,
        "jasowang@redhat.com" <jasowang@redhat.com>,
        "apw@canonical.com" <apw@canonical.com>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>
Subject: RE: [PATCH 6/8] Drivers: scsi: storvsc: Implement an abort handler
Thread-Topic: [PATCH 6/8] Drivers: scsi: storvsc: Implement an abort handler
Thread-Index: AQHPmwbaMJcVE9K7bk+ZFkv2/whfmJuXbd+AgACmi9CAAQSuAIAAzDFQgADAb4CAAFJ50A==
Date: Fri, 11 Jul 2014 14:49:17 +0000
Message-ID: <24b8bacd815e4c43add14f66c85ff61b@BY2PR03MB299.namprd03.prod.outlook.com>
References: <1404866789-26910-1-git-send-email-kys@microsoft.com>
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> -----Original Message-----
> From: Hannes Reinecke [mailto:hare@suse.de]
> Sent: Friday, July 11, 2014 2:53 AM
> To: KY Srinivasan; Christoph Hellwig
> Cc: linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> ohering@suse.com; jbottomley@parallels.com; jasowang@redhat.com;
> apw@canonical.com; linux-scsi@vger.kernel.org
> Subject: Re: [PATCH 6/8] Drivers: scsi: storvsc: Implement an abort handler
> 
> On 07/11/2014 12:26 AM, KY Srinivasan wrote:
> >
> >
> >> -----Original Message-----
> >> From: Christoph Hellwig [mailto:hch@infradead.org]
> >> Sent: Thursday, July 10, 2014 3:13 AM
> >> To: KY Srinivasan
> >> Cc: Christoph Hellwig; linux-kernel@vger.kernel.org;
> >> devel@linuxdriverproject.org; ohering@suse.com;
> >> jbottomley@parallels.com; jasowang@redhat.com; apw@canonical.com;
> >> linux-scsi@vger.kernel.org
> >> Subject: Re: [PATCH 6/8] Drivers: scsi: storvsc: Implement an abort
> >> handler
> >>
> >>
> >> Note that you could increase the timeout and/or implement an
> >> eh_timed_out handler that just returns BLK_EH_RESET_TIMER, but if the
> >> completion takes too long the expectation is that a command will
> >> eventually finish instead of beeing delayed by an unmound amount.
> >
> > I like this idea; I will implement a eh_timed_out_handler.
> >
> Something like this should be sufficient:
> 
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index
> e71a0d7..630ae81 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -1468,6 +1468,12 @@ static int storvsc_get_chs(struct scsi_device
> *sdev, stru ct block_device * bdev,
>          return 0;
>   }
> 
> +static enum blk_eh_timer_return
> +storvsc_timed_out_handler(struct scsi_cmnd *scmd) {
> +       return BLK_EH_RESET_TIMER;
> +}
> +
>   static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
>   {
>          struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
> @@ -1687,6 +1693,7 @@ static struct scsi_host_template scsi_driver = {
>          .name =                 "storvsc_host_t",
>          .bios_param =           storvsc_get_chs,
>          .queuecommand =         storvsc_queuecommand,
> +       .eh_timed_out =         storvsc_timed_out_handler,
>          .eh_host_reset_handler =        storvsc_host_reset_handler,
>          .slave_alloc =          storvsc_device_alloc,
>          .slave_destroy =        storvsc_device_destroy,
> 
> Cheers,

Thanks Hannes. Based on Christoph's feedback I have implemented exactly this patch. It is under test on Azure.
I will be re-spinning and posting the patches shortly.

K. Y
> 
> Hannes
> --
> Dr. Hannes Reinecke		      zSeries & Storage
> hare@suse.de			      +49 911 74053 688
> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N?rnberg
> GF: J. Hawn, J. Guild, F. Imend?rffer, HRB 16746 (AG N?rnberg)
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