This patch adds the following functionality to the FC transport: - dev_loss_tmo LLDD callback : Called to essentially confirm the deletion of an rport. Thus, it is called whenever the dev_loss_tmo fires, or when the rport is deleted due to other circumstances (module unload, etc). It is expected that the callback will initiate the termination of any outstanding i/o on the rport. - fast_io_fail_tmo and LLD callback: There are some cases where it may take a long while to truly determine device loss, but the system is in a multipathing configuration that if the i/o was failed quickly (faster than dev_loss_tmo), it could be redirected to a different path and completed sooner. Many thanks to Mike Reed who cleaned up the initial RFC in support of this post. The original RFC is at: http://marc.theaimsgroup.com/?l=linux-scsi&m=115505981027246&w=2 Note: This patch assumes 3 prior fc transport patches have been installed: http://marc.theaimsgroup.com/?l=linux-scsi&m=115555807316329&w=2 http://marc.theaimsgroup.com/?l=linux-scsi&m=115581614930261&w=2 http://marc.theaimsgroup.com/?l=linux-scsi&m=115593664816371&w=2 Sorry - next time I'll do something like making these individual patches of the same posting when I know they'll be posted closely together. -- james s Signed-off-by: James Smart <James.Smart@xxxxxxxxxx> diff -upNr a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c --- a/drivers/scsi/scsi_transport_fc.c 2006-08-18 10:35:16.000000000 -0400 +++ b/drivers/scsi/scsi_transport_fc.c 2006-08-18 17:04:54.000000000 -0400 @@ -242,6 +242,7 @@ fc_bitfield_name_search(remote_port_role static void fc_timeout_deleted_rport(void *data); +static void fc_timeout_fail_rport_io(void *data); static void fc_scsi_scan_rport(void *data); /* @@ -249,7 +250,7 @@ static void fc_scsi_scan_rport(void *dat * Increase these values if you add attributes */ #define FC_STARGET_NUM_ATTRS 3 -#define FC_RPORT_NUM_ATTRS 9 +#define FC_RPORT_NUM_ATTRS 10 #define FC_HOST_NUM_ATTRS 17 struct fc_internal { @@ -622,11 +623,14 @@ store_fc_rport_##field(struct class_devi struct fc_rport *rport = transport_class_to_rport(cdev); \ struct Scsi_Host *shost = rport_to_shost(rport); \ struct fc_internal *i = to_fc_internal(shost->transportt); \ + char *cp; \ if ((rport->port_state == FC_PORTSTATE_BLOCKED) || \ (rport->port_state == FC_PORTSTATE_DELETED) || \ (rport->port_state == FC_PORTSTATE_NOTPRESENT)) \ return -EBUSY; \ - val = simple_strtoul(buf, NULL, 0); \ + val = simple_strtoul(buf, &cp, 0); \ + if (*cp && (*cp != '\n')) \ + return -EINVAL; \ i->f->set_rport_##field(rport, val); \ return count; \ } @@ -708,6 +712,13 @@ static FC_CLASS_DEVICE_ATTR(rport, title if (i->f->show_rport_##field) \ count++ +#define SETUP_PRIVATE_RPORT_ATTRIBUTE_RW(field) \ +{ \ + i->private_rport_attrs[count] = class_device_attr_rport_##field; \ + i->rport_attrs[count] = &i->private_rport_attrs[count]; \ + count++; \ +} + /* The FC Transport Remote Port Attributes: */ @@ -740,12 +751,14 @@ store_fc_rport_dev_loss_tmo(struct class struct fc_rport *rport = transport_class_to_rport(cdev); struct Scsi_Host *shost = rport_to_shost(rport); struct fc_internal *i = to_fc_internal(shost->transportt); + char *cp; if ((rport->port_state == FC_PORTSTATE_BLOCKED) || (rport->port_state == FC_PORTSTATE_DELETED) || (rport->port_state == FC_PORTSTATE_NOTPRESENT)) return -EBUSY; - val = simple_strtoul(buf, NULL, 0); - if ((val < 0) || (val > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)) + val = simple_strtoul(buf, &cp, 0); + if ((*cp && (*cp != '\n')) || + (val < 0) || (val > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)) return -EINVAL; i->f->set_rport_dev_loss_tmo(rport, val); return count; @@ -795,6 +808,44 @@ static FC_CLASS_DEVICE_ATTR(rport, roles fc_private_rport_rd_enum_attr(port_state, FC_PORTSTATE_MAX_NAMELEN); fc_private_rport_rd_attr(scsi_target_id, "%d\n", 20); +/* + * fast_io_fail_tmo attribute + */ +static ssize_t +show_fc_rport_fast_io_fail_tmo (struct class_device *cdev, char *buf) +{ + struct fc_rport *rport = transport_class_to_rport(cdev); + + if (rport->fast_io_fail_tmo == -1) + return snprintf(buf, 5, "off\n"); + return snprintf(buf, 20, "%d\n", rport->fast_io_fail_tmo); +} + +static ssize_t +store_fc_rport_fast_io_fail_tmo(struct class_device *cdev, const char *buf, + size_t count) +{ + int val; + char *cp; + struct fc_rport *rport = transport_class_to_rport(cdev); + + if ((rport->port_state == FC_PORTSTATE_BLOCKED) || + (rport->port_state == FC_PORTSTATE_DELETED) || + (rport->port_state == FC_PORTSTATE_NOTPRESENT)) + return -EBUSY; + if (strncmp(buf, "off", 3) == 0) + rport->fast_io_fail_tmo = -1; + else { + val = simple_strtoul(buf, &cp, 0); + if ((*cp && (*cp != '\n')) || + (val < 0) || (val >= rport->dev_loss_tmo)) + return -EINVAL; + rport->fast_io_fail_tmo = val; + } + return count; +} +static FC_CLASS_DEVICE_ATTR(rport, fast_io_fail_tmo, S_IRUGO | S_IWUSR, + show_fc_rport_fast_io_fail_tmo, store_fc_rport_fast_io_fail_tmo); /* @@ -880,8 +931,11 @@ store_fc_host_##field(struct class_devic int val; \ struct Scsi_Host *shost = transport_class_to_shost(cdev); \ struct fc_internal *i = to_fc_internal(shost->transportt); \ + char *cp; \ \ - val = simple_strtoul(buf, NULL, 0); \ + val = simple_strtoul(buf, &cp, 0); \ + if (*cp && (*cp != '\n')) \ + return -EINVAL; \ i->f->set_host_##field(shost, val); \ return count; \ } @@ -1481,6 +1535,8 @@ fc_attach_transport(struct fc_function_t SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(roles); SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(port_state); SETUP_PRIVATE_RPORT_ATTRIBUTE_RD(scsi_target_id); + if (ft->terminate_rport_io) + SETUP_PRIVATE_RPORT_ATTRIBUTE_RW(fast_io_fail_tmo); BUG_ON(count > FC_RPORT_NUM_ATTRS); @@ -1552,7 +1608,7 @@ fc_flush_work(struct Scsi_Host *shost) * @delay: jiffies to delay the work queuing * * Return value: - * 0 on success / != 0 for error + * 1 on success / 0 already queued / < 0 for error **/ static int fc_queue_devloss_work(struct Scsi_Host *shost, struct work_struct *work, @@ -1567,6 +1623,9 @@ fc_queue_devloss_work(struct Scsi_Host * return -EINVAL; } + if (delay == 0) + return queue_work(fc_host_devloss_work_q(shost), work); + return queue_delayed_work(fc_host_devloss_work_q(shost), work, delay); } @@ -1659,10 +1718,23 @@ fc_starget_delete(void *data) struct fc_rport *rport = (struct fc_rport *)data; struct Scsi_Host *shost = rport_to_shost(rport); unsigned long flags; + struct fc_internal *i = to_fc_internal(shost->transportt); + + /* + * Involve the LLDD if possible. All io on the rport is to + * be terminated, either as part of the dev_loss_tmo callback + * processing, or via the terminate_rport_io function. + */ + if (i->f->dev_loss_tmo_callbk) + i->f->dev_loss_tmo_callbk(rport); + else if (i->f->terminate_rport_io) + i->f->terminate_rport_io(rport); spin_lock_irqsave(shost->host_lock, flags); if (rport->flags & FC_RPORT_DEVLOSS_PENDING) { spin_unlock_irqrestore(shost->host_lock, flags); + if (!cancel_delayed_work(&rport->fail_io_work)) + fc_flush_devloss(shost); if (!cancel_delayed_work(&rport->dev_loss_work)) fc_flush_devloss(shost); spin_lock_irqsave(shost->host_lock, flags); @@ -1685,10 +1757,7 @@ fc_rport_final_delete(void *data) struct fc_rport *rport = (struct fc_rport *)data; struct device *dev = &rport->dev; struct Scsi_Host *shost = rport_to_shost(rport); - - /* Delete SCSI target and sdevs */ - if (rport->scsi_target_id != -1) - fc_starget_delete(data); + struct fc_internal *i = to_fc_internal(shost->transportt); /* * if a scan is pending, flush the SCSI Host work_q so that @@ -1697,6 +1766,14 @@ fc_rport_final_delete(void *data) if (rport->flags & FC_RPORT_SCAN_PENDING) scsi_flush_work(shost); + /* Delete SCSI target and sdevs */ + if (rport->scsi_target_id != -1) + fc_starget_delete(data); + else if (i->f->dev_loss_tmo_callbk) + i->f->dev_loss_tmo_callbk(rport); + else if (i->f->terminate_rport_io) + i->f->terminate_rport_io(rport); + transport_remove_device(dev); device_del(dev); transport_destroy_device(dev); @@ -1748,8 +1825,10 @@ fc_rport_create(struct Scsi_Host *shost, if (fci->f->dd_fcrport_size) rport->dd_data = &rport[1]; rport->channel = channel; + rport->fast_io_fail_tmo = -1; INIT_WORK(&rport->dev_loss_work, fc_timeout_deleted_rport, rport); + INIT_WORK(&rport->fail_io_work, fc_timeout_fail_rport_io, rport); INIT_WORK(&rport->scan_work, fc_scsi_scan_rport, rport); INIT_WORK(&rport->stgt_delete_work, fc_starget_delete, rport); INIT_WORK(&rport->rport_delete_work, fc_rport_final_delete, rport); @@ -1913,11 +1992,13 @@ fc_remote_port_add(struct Scsi_Host *sho /* restart the target */ /* - * Stop the target timer first. Take no action + * Stop the target timers first. Take no action * on the del_timer failure as the state * machine state change will validate the * transaction. */ + if (!cancel_delayed_work(&rport->fail_io_work)) + fc_flush_devloss(shost); if (!cancel_delayed_work(work)) fc_flush_devloss(shost); @@ -2061,6 +2142,7 @@ void fc_remote_port_delete(struct fc_rport *rport) { struct Scsi_Host *shost = rport_to_shost(rport); + struct fc_internal *i = to_fc_internal(shost->transportt); int timeout = rport->dev_loss_tmo; unsigned long flags; @@ -2091,6 +2173,12 @@ fc_remote_port_delete(struct fc_rport * scsi_target_block(&rport->dev); + /* see if we need to kill io faster than waiting for device loss */ + if ((rport->fast_io_fail_tmo != -1) && + (rport->fast_io_fail_tmo < timeout) && (i->f->terminate_rport_io)) + fc_queue_devloss_work(shost, &rport->fail_io_work, + rport->fast_io_fail_tmo * HZ); + /* cap the length the devices can be blocked until they are deleted */ fc_queue_devloss_work(shost, &rport->dev_loss_work, timeout * HZ); } @@ -2150,6 +2238,8 @@ fc_remote_port_rolechg(struct fc_rport * machine state change will validate the * transaction. */ + if (!cancel_delayed_work(&rport->fail_io_work)) + fc_flush_devloss(shost); if (!cancel_delayed_work(&rport->dev_loss_work)) fc_flush_devloss(shost); @@ -2271,6 +2361,28 @@ fc_timeout_deleted_rport(void *data) } /** + * fc_timeout_fail_rport_io - Timeout handler for a fast io failing on a + * disconnected SCSI target. + * + * @data: rport to terminate io on. + * + * Notes: Only requests the failure of the io, not that all are flushed + * prior to returning. + **/ +static void +fc_timeout_fail_rport_io(void *data) +{ + struct fc_rport *rport = (struct fc_rport *)data; + struct Scsi_Host *shost = rport_to_shost(rport); + struct fc_internal *i = to_fc_internal(shost->transportt); + + if (rport->port_state != FC_PORTSTATE_BLOCKED) + return; + + i->f->terminate_rport_io(rport); +} + +/** * fc_scsi_scan_rport - called to perform a scsi scan on a remote port. * * @data: remote port to be scanned. diff -upNr a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h --- a/include/scsi/scsi_transport_fc.h 2006-08-18 10:35:17.000000000 -0400 +++ b/include/scsi/scsi_transport_fc.h 2006-08-18 15:40:51.000000000 -0400 @@ -195,6 +195,7 @@ struct fc_rport { /* aka fc_starget_attr u32 roles; enum fc_port_state port_state; /* Will only be ONLINE or UNKNOWN */ u32 scsi_target_id; + u32 fast_io_fail_tmo; /* exported data */ void *dd_data; /* Used for driver-specific storage */ @@ -207,6 +208,7 @@ struct fc_rport { /* aka fc_starget_attr struct device dev; struct work_struct dev_loss_work; struct work_struct scan_work; + struct work_struct fail_io_work; struct work_struct stgt_delete_work; struct work_struct rport_delete_work; } __attribute__((aligned(sizeof(unsigned long)))); @@ -445,6 +447,9 @@ struct fc_function_template { int (*issue_fc_host_lip)(struct Scsi_Host *); + void (*dev_loss_tmo_callbk)(struct fc_rport *); + void (*terminate_rport_io)(struct fc_rport *); + /* allocation lengths for host-specific data */ u32 dd_fcrport_size; - 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
