From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: [PATCH 06/12] scsi_transport_srp: Reduce failover time Date: Thu, 30 Apr 2015 10:59:45 +0200 Message-ID: <5541EF01.3030008@sandisk.com> References: <5541EE21.3050809@sandisk.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5541EE21.3050809@sandisk.com> Sender: linux-scsi-owner@vger.kernel.org To: Doug Ledford Cc: James Bottomley , Sagi Grimberg , Sebastian Parschauer , linux-rdma , "linux-scsi@vger.kernel.org" List-Id: linux-rdma@vger.kernel.org Unlike FC, there is no risk that SCSI devices will be offlined by the error handler if it is started while a reconnect attempt is ongoing. Hence report timeout errors as soon as possible if a higher software layer (e.g. multipathd) needs to be informed about a timeout. It is assumed that if both fast_io_fail_tmo < 0 and rport->dev_loss_tmo < 0 that this means that there is no need to report timeouts quickly. Signed-off-by: Bart Van Assche Cc: James Bottomley Cc: Sagi Grimberg Cc: Sebastian Parschauer --- drivers/scsi/scsi_transport_srp.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c index 4a44337..6667c2b 100644 --- a/drivers/scsi/scsi_transport_srp.c +++ b/drivers/scsi/scsi_transport_srp.c @@ -61,6 +61,11 @@ static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r) return dev_to_shost(r->dev.parent); } +static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost) +{ + return transport_class_to_srp_rport(&shost->shost_gendev); +} + /** * srp_tmo_valid() - check timeout combination validity * @reconnect_delay: Reconnect delay in seconds. @@ -626,9 +631,11 @@ static enum blk_eh_timer_return srp_timed_out(struct scsi_cmnd *scmd) struct scsi_device *sdev = scmd->device; struct Scsi_Host *shost = sdev->host; struct srp_internal *i = to_srp_internal(shost->transportt); + struct srp_rport *rport = shost_to_rport(shost); pr_debug("timeout for sdev %s\n", dev_name(&sdev->sdev_gendev)); - return i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ? + return rport->fast_io_fail_tmo < 0 && rport->dev_loss_tmo < 0 && + i->f->reset_timer_if_blocked && scsi_device_blocked(sdev) ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED; } -- 2.1.4