From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH v12 6/6] Avoid re-enabling I/O after the transport became offline Date: Mon, 01 Jul 2013 10:27:56 +0200 Message-ID: <51D13D8C.9070407@suse.de> References: <51CC5176.90609@acm.org> <51CC52EB.9040900@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:46133 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751375Ab3GAI15 (ORCPT ); Mon, 1 Jul 2013 04:27:57 -0400 In-Reply-To: <51CC52EB.9040900@acm.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Bart Van Assche Cc: James Bottomley , Mike Christie , Chanho Min , Joe Lawrence , linux-scsi , David Milburn , Tejun Heo On 06/27/2013 04:57 PM, Bart Van Assche wrote: > Disallow the SDEV_TRANSPORT_OFFLINE to SDEV_CANCEL transition such > that no I/O is sent to devices for which the transport is offline. > Notes: > - Functions like sd_shutdown() use scsi_execute_req() and hence > set the REQ_PREEMPT flag. Such requests are passed to the LLD > queuecommand callback in the SDEV_CANCEL state. > - This patch does not affect Fibre Channel LLD drivers since these > drivers invoke fc_remote_port_chkready() before submitting a SCSI > request to the HBA. That prevents a timeout to occur in state > SDEV_CANCEL if the transport is offline. >=20 > Signed-off-by: Bart Van Assche > Cc: Mike Christie > Cc: James Bottomley > Cc: Hannes Reinecke > Cc: Tejun Heo > --- > drivers/scsi/scsi_lib.c | 1 - > drivers/scsi/scsi_sysfs.c | 4 +++- > 2 files changed, 3 insertions(+), 2 deletions(-) >=20 > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index 6a4fde7..63875c3 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -2180,7 +2180,6 @@ scsi_device_set_state(struct scsi_device *sdev,= enum scsi_device_state state) > case SDEV_RUNNING: > case SDEV_QUIESCE: > case SDEV_OFFLINE: > - case SDEV_TRANSPORT_OFFLINE: > case SDEV_BLOCK: > break; > default: > diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c > index dfbaa34..666b741 100644 > --- a/drivers/scsi/scsi_sysfs.c > +++ b/drivers/scsi/scsi_sysfs.c > @@ -959,14 +959,16 @@ void __scsi_remove_device(struct scsi_device *s= dev) > { > struct Scsi_Host *shost =3D sdev->host; > struct device *dev =3D &sdev->sdev_gendev; > + enum scsi_device_state sdev_state; > int res; > =20 > if (sdev->is_visible) { > spin_lock_irq(shost->host_lock); > + sdev_state =3D sdev->sdev_state; > res =3D scsi_device_set_state(sdev, SDEV_CANCEL); > spin_unlock_irq(shost->host_lock); > =20 > - if (res !=3D 0) > + if (res !=3D 0 && sdev_state !=3D SDEV_TRANSPORT_OFFLINE) > return; > =20 > bsg_unregister_queue(sdev->request_queue); >=20 Hmm. This is really subtle. Do you mind adding inserting a comment here on why this is required? Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html