/**
* srp_reconnect_rport() - reconnect to an SRP target port
* @rport: SRP target port.
*
* Blocks SCSI command queueing before invoking reconnect() such that
* queuecommand() won't be invoked concurrently with reconnect() from outside
* the SCSI EH. This is important since a reconnect() implementation may
* reallocate resources needed by queuecommand().
*
* Notes:
* - This function neither waits until outstanding requests have finished nor
* tries to abort these. It is the responsibility of the reconnect()
* function to finish outstanding commands before reconnecting to the target
* port.
* - It is the responsibility of the caller to ensure that the resources
* reallocated by the reconnect() function won't be used while this function
* is in progress. One possible strategy is to invoke this function from
* the context of the SCSI EH thread only. Another possible strategy is to
* lock the rport mutex inside each SCSI LLD callback that can be invoked by
* the SCSI EH (the scsi_host_template.eh_*() functions and also the
* scsi_host_template.queuecommand() function).
*/
int srp_reconnect_rport(struct srp_rport *rport)
{
struct Scsi_Host *shost = rport_to_shost(rport);
struct srp_internal *i = to_srp_internal(shost->transportt);
struct scsi_device *sdev;
int res;
pr_debug("SCSI host %s\n", dev_name(&shost->shost_gendev));
res = mutex_lock_interruptible(&rport->mutex);
if (res)
goto out;
scsi_target_block(&shost->shost_gendev);
res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
pr_debug("%s (state %d): transport.reconnect() returned %d\n",
dev_name(&shost->shost_gendev), rport->state, res);
if (res == 0) {
cancel_delayed_work(&rport->fast_io_fail_work);
cancel_delayed_work(&rport->dev_loss_work);
rport->failed_reconnects = 0;
srp_rport_set_state(rport, SRP_RPORT_RUNNING);
scsi_target_unblock(&shost->shost_gendev, SDEV_RUNNING);
/*
* If the SCSI error handler has offlined one or more devices,
* invoking scsi_target_unblock() won't change the state of
* these devices into running so do that explicitly.
*/
spin_lock_irq(shost->host_lock);
__shost_for_each_device(sdev, shost)
if (sdev->sdev_state == SDEV_OFFLINE)
sdev->sdev_state = SDEV_RUNNING;
spin_unlock_irq(shost->host_lock);
} else if (rport->state == SRP_RPORT_RUNNING) {
static ssize_t store_srp_rport_delete(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct srp_rport *rport = transport_class_to_srp_rport(dev);
struct Scsi_Host *shost = dev_to_shost(dev);
struct srp_internal *i = to_srp_internal(shost->transportt);
if (i->f->rport_delete) {
i->f->rport_delete(rport);
return count;
} else {
return -ENOSYS;
}
}
static void __rport_fail_io_fast(struct srp_rport *rport)
{
struct Scsi_Host *shost = rport_to_shost(rport);
struct srp_internal *i;
lockdep_assert_held(&rport->mutex);
if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST))
return;
scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
/* Involve the LLD if possible to terminate all I/O on the rport. */
i = to_srp_internal(shost->transportt);
if (i->f->terminate_rport_io)
i->f->terminate_rport_io(rport);
}
/**
* rport_dev_loss_timedout() - device loss timeout handler
* @work: Work structure used for scheduling this operation.
*/
static void rport_dev_loss_timedout(struct work_struct *work)
{
struct srp_rport *rport = container_of(to_delayed_work(work),
struct srp_rport, dev_loss_work);
struct Scsi_Host *shost = rport_to_shost(rport);
struct srp_internal *i = to_srp_internal(shost->transportt);
pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
dev_name(&rport->dev), dev_name(&shost->shost_gendev));
mutex_lock(&rport->mutex);
WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
mutex_unlock(&rport->mutex);
i->f->rport_delete(rport);
}
static void __rport_fail_io_fast(struct srp_rport *rport)
{
struct Scsi_Host *shost = rport_to_shost(rport);
struct srp_internal *i;
lockdep_assert_held(&rport->mutex);
if (srp_rport_set_state(rport, SRP_RPORT_FAIL_FAST))
return;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0) || defined(CONFIG_COMPAT_SCSI_TARGET_UNBLOCK)
scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
#else
scsi_target_unblock(rport->dev.parent);
#endif
/* Involve the LLD if possible to terminate all I/O on the rport. */
i = to_srp_internal(shost->transportt);
if (i->f->terminate_rport_io)
i->f->terminate_rport_io(rport);
}
/**
* rport_dev_loss_timedout() - device loss timeout handler
* @work: Work structure used for scheduling this operation.
*/
static void rport_dev_loss_timedout(struct work_struct *work)
{
struct srp_rport *rport = container_of(to_delayed_work(work),
struct srp_rport, dev_loss_work);
struct Scsi_Host *shost = rport_to_shost(rport);
struct srp_internal *i = to_srp_internal(shost->transportt);
pr_info("dev_loss_tmo expired for SRP %s / %s.\n",
dev_name(&rport->dev), dev_name(&shost->shost_gendev));
mutex_lock(&rport->mutex);
WARN_ON(srp_rport_set_state(rport, SRP_RPORT_LOST) != 0);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 6, 0) || defined(CONFIG_COMPAT_SCSI_TARGET_UNBLOCK)
scsi_target_unblock(rport->dev.parent, SDEV_TRANSPORT_OFFLINE);
#else
scsi_target_unblock(rport->dev.parent);
#endif
mutex_unlock(&rport->mutex);
i->f->rport_delete(rport);
}
