> -----Original Message----- > From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi- > owner@xxxxxxxxxxxxxxx] On Behalf Of Rob Evers > Sent: Friday, May 18, 2012 1:09 PM > To: linux-scsi@xxxxxxxxxxxxxxx > Subject: [PATCH 1/3 V2] alua: implement 'implied transition timeout' > > During alua transitions, an array can return transitioning > status in response to rtpg requests. These requests get > retried for a maximum of 60 seconds by default before timing > out. Sometimes this timeout isn't sufficient to allow the > array to complete the transition. T10-spc4 addresses this > under 'Report Target Port Groups' command. > > This update retrieves the timeout value from the storage > array if available and retries the transitioning rtpgs > for up to the 'implied transitioning timeout' value > > Signed-off-by: Rob Evers <revers@xxxxxxxxxx> Reviewed-by: Babu Moger <babu.moger@xxxxxxxxxx> > --- > drivers/scsi/device_handler/scsi_dh_alua.c | 41 > ++++++++++++++++++++++++--- > include/scsi/scsi.h | 2 + > 2 files changed, 38 insertions(+), 5 deletions(-) > > diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c > b/drivers/scsi/device_handler/scsi_dh_alua.c > index 04c5cea..6a7efd3 100644 > --- a/drivers/scsi/device_handler/scsi_dh_alua.c > +++ b/drivers/scsi/device_handler/scsi_dh_alua.c > @@ -46,13 +46,16 @@ > #define TPGS_SUPPORT_OFFLINE 0x40 > #define TPGS_SUPPORT_TRANSITION 0x80 > > +#define RTPG_FMT_MASK 0x70 > +#define RTPG_FMT_EXT_HDR 0x10 > + > #define TPGS_MODE_UNINITIALIZED -1 > #define TPGS_MODE_NONE 0x0 > #define TPGS_MODE_IMPLICIT 0x1 > #define TPGS_MODE_EXPLICIT 0x2 > > #define ALUA_INQUIRY_SIZE 36 > -#define ALUA_FAILOVER_TIMEOUT (60 * HZ) > +#define ALUA_FAILOVER_TIMEOUT 60 > #define ALUA_FAILOVER_RETRIES 5 > > struct alua_dh_data { > @@ -63,6 +66,7 @@ struct alua_dh_data { > unsigned char inq[ALUA_INQUIRY_SIZE]; > unsigned char *buff; > int bufflen; > + unsigned char transition_tmo; > unsigned char sense[SCSI_SENSE_BUFFERSIZE]; > int senselen; > struct scsi_device *sdev; > @@ -123,7 +127,7 @@ static struct request *get_alua_req(struct scsi_device > *sdev, > rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT > | > REQ_FAILFAST_DRIVER; > rq->retries = ALUA_FAILOVER_RETRIES; > - rq->timeout = ALUA_FAILOVER_TIMEOUT; > + rq->timeout = ALUA_FAILOVER_TIMEOUT * HZ; > > return rq; > } > @@ -180,7 +184,7 @@ static unsigned submit_rtpg(struct scsi_device *sdev, > struct alua_dh_data *h) > > /* Prepare the command. */ > rq->cmd[0] = MAINTENANCE_IN; > - rq->cmd[1] = MI_REPORT_TARGET_PGS; > + rq->cmd[1] = MI_REPORT_TARGET_PGS | > MI_EXT_HDR_PARAM_FMT; > rq->cmd[6] = (h->bufflen >> 24) & 0xff; > rq->cmd[7] = (h->bufflen >> 16) & 0xff; > rq->cmd[8] = (h->bufflen >> 8) & 0xff; > @@ -514,8 +518,14 @@ static int alua_rtpg(struct scsi_device *sdev, struct > alua_dh_data *h) > unsigned char *ucp; > unsigned err; > unsigned long expiry, interval = 1000; > + unsigned int tpg_desc_tbl_off; > + unsigned char orig_transition_tmo; > + > + if (!h->transition_tmo) > + expiry = round_jiffies_up(jiffies + > ALUA_FAILOVER_TIMEOUT * HZ); > + else > + expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ); > > - expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT); > retry: > err = submit_rtpg(sdev, h); > > @@ -551,7 +561,28 @@ static int alua_rtpg(struct scsi_device *sdev, struct > alua_dh_data *h) > goto retry; > } > > - for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) { > + orig_transition_tmo = h->transition_tmo; > + if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && h- > >buff[5] != 0) > + h->transition_tmo = h->buff[5]; > + else > + h->transition_tmo = ALUA_FAILOVER_TIMEOUT; > + > + if (orig_transition_tmo != h->transition_tmo) { > + sdev_printk(KERN_INFO, sdev, > + "%s: transition timeout set to %d seconds\n", > + ALUA_DH_NAME, h->transition_tmo); > + expiry = jiffies + h->transition_tmo * HZ; > + } > + > + if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR) > + tpg_desc_tbl_off = 8; > + else > + tpg_desc_tbl_off = 4; > + > + for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off; > + k < len; > + k += off, ucp += off) { > + > if (h->group_id == (ucp[2] << 8) + ucp[3]) { > h->state = ucp[0] & 0x0f; > valid_states = ucp[1]; > diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h > index f34a5a8..c6f0974 100644 > --- a/include/scsi/scsi.h > +++ b/include/scsi/scsi.h > @@ -161,6 +161,8 @@ struct scsi_cmnd; > #define MI_REPORT_PRIORITY 0x0e > #define MI_REPORT_TIMESTAMP 0x0f > #define MI_MANAGEMENT_PROTOCOL_IN 0x10 > +/* value for MI_REPORT_TARGET_PGS ext header */ > +#define MI_EXT_HDR_PARAM_FMT 0x20 > /* values for maintenance out */ > #define MO_SET_IDENTIFYING_INFORMATION 0x06 > #define MO_SET_TARGET_PGS 0x0a > -- > 1.7.7.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
