On 08/25/2011 07:36 AM, michaelc@xxxxxxxxxxx wrote:
> From: Mike Christie <michaelc@xxxxxxxxxxx>
>
> The problem is that if we are doing a scsi scan then the device goes
> into recovery then we will wait for the recovery to complete. It waits
> because scsi-ml will send inquiries or report luns and the queueing code
> will have been blocked due to the host not being ready. However, if we
> are in recovery and then a scan is started the scan will silently fail
> and some devices will not be added.
>
> It is easy to hit the problem where devices do not show up with
> FC where we are doing tests that disrupt the target controllers.
> When the controller is disruprted (reboot, or setting firmware, etc),
> and we cause the dev loss tmo to fire then devices will be removed
> Then when the problem has been fixed, the rport will be scanned and
> devices should be added back. But if we cause another disruption before
> scanning has started then devices will not get added back. If the problem
> is not started until the scan is started then the devices will be added
> back.
>
> This patch fixes that problem by not failing scans when the host
> is in recovery. We will let scsi-ml send the IO and let the queueing
> and scsi error handling deal with it like is done if we went into
> recovery while scanning.
>
> For recovery cases where the host is being torn down then with the
> patch we will still fail the scan since there is not point in scanning.
>
> Patch was made and tested over scsi-misc.
>
>
> Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
> ---
> include/scsi/scsi_host.h | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
> index f1f2644..22b7b23 100644
> --- a/include/scsi/scsi_host.h
> +++ b/include/scsi/scsi_host.h
> @@ -791,7 +791,8 @@ static inline struct device *scsi_get_device(struct Scsi_Host *shost)
> **/
> static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
> {
> - return shost->shost_state == SHOST_RUNNING;
> + return shost->shost_state == SHOST_RUNNING ||
> + shost->shost_state == SHOST_RECOVERY;
> }
>
> extern void scsi_unblock_requests(struct Scsi_Host *);
James, ping?
Any reason it was not included?
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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