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authorBart Van Assche <bart.vanassche@sandisk.com>2015-05-18 13:24:38 +0200
committerDoug Ledford <dledford@redhat.com>2015-05-18 13:35:55 -0400
commite68ca75200fed4700471fb84ea0d09e25f269654 (patch)
tree9e3edf242fac69f72abe78a9228629bce7da1cc8
parenta44074f14ba1ea0747ea737026eb929b81993dc3 (diff)
scsi_transport_srp: Reduce failover time
Unlike FC, there is no risk that SCSI devices will be offlined by the SCSI error handler if the SCSI error handler 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 <bart.vanassche@sandisk.com> Cc: James Bottomley <JBottomley@Odin.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
-rw-r--r--drivers/scsi/scsi_transport_srp.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index f115f67a6ba5..a85292b1d09d 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.
@@ -628,9 +633,11 @@ 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;
}