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-rw-r--r--drivers/scsi/scsi_transport_srp.c900
1 files changed, 900 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
new file mode 100644
index 000000000..98a34ed10
--- /dev/null
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -0,0 +1,900 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SCSI RDMA (SRP) transport class
+ *
+ * Copyright (C) 2007 FUJITA Tomonori <tomof@acm.org>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/jiffies.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_transport.h>
+#include <scsi/scsi_transport_srp.h>
+#include "scsi_priv.h"
+
+struct srp_host_attrs {
+ atomic_t next_port_id;
+};
+#define to_srp_host_attrs(host) ((struct srp_host_attrs *)(host)->shost_data)
+
+#define SRP_HOST_ATTRS 0
+#define SRP_RPORT_ATTRS 8
+
+struct srp_internal {
+ struct scsi_transport_template t;
+ struct srp_function_template *f;
+
+ struct device_attribute *host_attrs[SRP_HOST_ATTRS + 1];
+
+ struct device_attribute *rport_attrs[SRP_RPORT_ATTRS + 1];
+ struct transport_container rport_attr_cont;
+};
+
+static int scsi_is_srp_rport(const struct device *dev);
+
+#define to_srp_internal(tmpl) container_of(tmpl, struct srp_internal, t)
+
+#define dev_to_rport(d) container_of(d, struct srp_rport, dev)
+#define transport_class_to_srp_rport(dev) dev_to_rport((dev)->parent)
+static inline struct Scsi_Host *rport_to_shost(struct srp_rport *r)
+{
+ return dev_to_shost(r->dev.parent);
+}
+
+static int find_child_rport(struct device *dev, void *data)
+{
+ struct device **child = data;
+
+ if (scsi_is_srp_rport(dev)) {
+ WARN_ON_ONCE(*child);
+ *child = dev;
+ }
+ return 0;
+}
+
+static inline struct srp_rport *shost_to_rport(struct Scsi_Host *shost)
+{
+ struct device *child = NULL;
+
+ WARN_ON_ONCE(device_for_each_child(&shost->shost_gendev, &child,
+ find_child_rport) < 0);
+ return child ? dev_to_rport(child) : NULL;
+}
+
+/**
+ * srp_tmo_valid() - check timeout combination validity
+ * @reconnect_delay: Reconnect delay in seconds.
+ * @fast_io_fail_tmo: Fast I/O fail timeout in seconds.
+ * @dev_loss_tmo: Device loss timeout in seconds.
+ *
+ * The combination of the timeout parameters must be such that SCSI commands
+ * are finished in a reasonable time. Hence do not allow the fast I/O fail
+ * timeout to exceed SCSI_DEVICE_BLOCK_MAX_TIMEOUT nor allow dev_loss_tmo to
+ * exceed that limit if failing I/O fast has been disabled. Furthermore, these
+ * parameters must be such that multipath can detect failed paths timely.
+ * Hence do not allow all three parameters to be disabled simultaneously.
+ */
+int srp_tmo_valid(int reconnect_delay, int fast_io_fail_tmo, long dev_loss_tmo)
+{
+ if (reconnect_delay < 0 && fast_io_fail_tmo < 0 && dev_loss_tmo < 0)
+ return -EINVAL;
+ if (reconnect_delay == 0)
+ return -EINVAL;
+ if (fast_io_fail_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
+ return -EINVAL;
+ if (fast_io_fail_tmo < 0 &&
+ dev_loss_tmo > SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
+ return -EINVAL;
+ if (dev_loss_tmo >= LONG_MAX / HZ)
+ return -EINVAL;
+ if (fast_io_fail_tmo >= 0 && dev_loss_tmo >= 0 &&
+ fast_io_fail_tmo >= dev_loss_tmo)
+ return -EINVAL;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(srp_tmo_valid);
+
+static int srp_host_setup(struct transport_container *tc, struct device *dev,
+ struct device *cdev)
+{
+ struct Scsi_Host *shost = dev_to_shost(dev);
+ struct srp_host_attrs *srp_host = to_srp_host_attrs(shost);
+
+ atomic_set(&srp_host->next_port_id, 0);
+ return 0;
+}
+
+static DECLARE_TRANSPORT_CLASS(srp_host_class, "srp_host", srp_host_setup,
+ NULL, NULL);
+
+static DECLARE_TRANSPORT_CLASS(srp_rport_class, "srp_remote_ports",
+ NULL, NULL, NULL);
+
+static ssize_t
+show_srp_rport_id(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+ return sprintf(buf, "%16phC\n", rport->port_id);
+}
+
+static DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
+
+static const struct {
+ u32 value;
+ char *name;
+} srp_rport_role_names[] = {
+ {SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
+ {SRP_RPORT_ROLE_TARGET, "SRP Target"},
+};
+
+static ssize_t
+show_srp_rport_roles(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
+ if (srp_rport_role_names[i].value == rport->roles) {
+ name = srp_rport_role_names[i].name;
+ break;
+ }
+ return sprintf(buf, "%s\n", name ? : "unknown");
+}
+
+static DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
+
+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 DEVICE_ATTR(delete, S_IWUSR, NULL, store_srp_rport_delete);
+
+static ssize_t show_srp_rport_state(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ static const char *const state_name[] = {
+ [SRP_RPORT_RUNNING] = "running",
+ [SRP_RPORT_BLOCKED] = "blocked",
+ [SRP_RPORT_FAIL_FAST] = "fail-fast",
+ [SRP_RPORT_LOST] = "lost",
+ };
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+ enum srp_rport_state state = rport->state;
+
+ return sprintf(buf, "%s\n",
+ (unsigned)state < ARRAY_SIZE(state_name) ?
+ state_name[state] : "???");
+}
+
+static DEVICE_ATTR(state, S_IRUGO, show_srp_rport_state, NULL);
+
+static ssize_t srp_show_tmo(char *buf, int tmo)
+{
+ return tmo >= 0 ? sprintf(buf, "%d\n", tmo) : sprintf(buf, "off\n");
+}
+
+int srp_parse_tmo(int *tmo, const char *buf)
+{
+ int res = 0;
+
+ if (strncmp(buf, "off", 3) != 0)
+ res = kstrtoint(buf, 0, tmo);
+ else
+ *tmo = -1;
+
+ return res;
+}
+EXPORT_SYMBOL(srp_parse_tmo);
+
+static ssize_t show_reconnect_delay(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+
+ return srp_show_tmo(buf, rport->reconnect_delay);
+}
+
+static ssize_t store_reconnect_delay(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, const size_t count)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+ int res, delay;
+
+ res = srp_parse_tmo(&delay, buf);
+ if (res)
+ goto out;
+ res = srp_tmo_valid(delay, rport->fast_io_fail_tmo,
+ rport->dev_loss_tmo);
+ if (res)
+ goto out;
+
+ if (rport->reconnect_delay <= 0 && delay > 0 &&
+ rport->state != SRP_RPORT_RUNNING) {
+ queue_delayed_work(system_long_wq, &rport->reconnect_work,
+ delay * HZ);
+ } else if (delay <= 0) {
+ cancel_delayed_work(&rport->reconnect_work);
+ }
+ rport->reconnect_delay = delay;
+ res = count;
+
+out:
+ return res;
+}
+
+static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR, show_reconnect_delay,
+ store_reconnect_delay);
+
+static ssize_t show_failed_reconnects(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+
+ return sprintf(buf, "%d\n", rport->failed_reconnects);
+}
+
+static DEVICE_ATTR(failed_reconnects, S_IRUGO, show_failed_reconnects, NULL);
+
+static ssize_t show_srp_rport_fast_io_fail_tmo(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+
+ return srp_show_tmo(buf, rport->fast_io_fail_tmo);
+}
+
+static ssize_t store_srp_rport_fast_io_fail_tmo(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+ int res;
+ int fast_io_fail_tmo;
+
+ res = srp_parse_tmo(&fast_io_fail_tmo, buf);
+ if (res)
+ goto out;
+ res = srp_tmo_valid(rport->reconnect_delay, fast_io_fail_tmo,
+ rport->dev_loss_tmo);
+ if (res)
+ goto out;
+ rport->fast_io_fail_tmo = fast_io_fail_tmo;
+ res = count;
+
+out:
+ return res;
+}
+
+static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
+ show_srp_rport_fast_io_fail_tmo,
+ store_srp_rport_fast_io_fail_tmo);
+
+static ssize_t show_srp_rport_dev_loss_tmo(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+
+ return srp_show_tmo(buf, rport->dev_loss_tmo);
+}
+
+static ssize_t store_srp_rport_dev_loss_tmo(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct srp_rport *rport = transport_class_to_srp_rport(dev);
+ int res;
+ int dev_loss_tmo;
+
+ res = srp_parse_tmo(&dev_loss_tmo, buf);
+ if (res)
+ goto out;
+ res = srp_tmo_valid(rport->reconnect_delay, rport->fast_io_fail_tmo,
+ dev_loss_tmo);
+ if (res)
+ goto out;
+ rport->dev_loss_tmo = dev_loss_tmo;
+ res = count;
+
+out:
+ return res;
+}
+
+static DEVICE_ATTR(dev_loss_tmo, S_IRUGO | S_IWUSR,
+ show_srp_rport_dev_loss_tmo,
+ store_srp_rport_dev_loss_tmo);
+
+static int srp_rport_set_state(struct srp_rport *rport,
+ enum srp_rport_state new_state)
+{
+ enum srp_rport_state old_state = rport->state;
+
+ lockdep_assert_held(&rport->mutex);
+
+ switch (new_state) {
+ case SRP_RPORT_RUNNING:
+ switch (old_state) {
+ case SRP_RPORT_LOST:
+ goto invalid;
+ default:
+ break;
+ }
+ break;
+ case SRP_RPORT_BLOCKED:
+ switch (old_state) {
+ case SRP_RPORT_RUNNING:
+ break;
+ default:
+ goto invalid;
+ }
+ break;
+ case SRP_RPORT_FAIL_FAST:
+ switch (old_state) {
+ case SRP_RPORT_LOST:
+ goto invalid;
+ default:
+ break;
+ }
+ break;
+ case SRP_RPORT_LOST:
+ break;
+ }
+ rport->state = new_state;
+ return 0;
+
+invalid:
+ return -EINVAL;
+}
+
+/**
+ * srp_reconnect_work() - reconnect and schedule a new attempt if necessary
+ * @work: Work structure used for scheduling this operation.
+ */
+static void srp_reconnect_work(struct work_struct *work)
+{
+ struct srp_rport *rport = container_of(to_delayed_work(work),
+ struct srp_rport, reconnect_work);
+ struct Scsi_Host *shost = rport_to_shost(rport);
+ int delay, res;
+
+ res = srp_reconnect_rport(rport);
+ if (res != 0) {
+ shost_printk(KERN_ERR, shost,
+ "reconnect attempt %d failed (%d)\n",
+ ++rport->failed_reconnects, res);
+ delay = rport->reconnect_delay *
+ min(100, max(1, rport->failed_reconnects - 10));
+ if (delay > 0)
+ queue_delayed_work(system_long_wq,
+ &rport->reconnect_work, delay * HZ);
+ }
+}
+
+/*
+ * scsi_target_block() must have been called before this function is
+ * called to guarantee that no .queuecommand() calls are in progress.
+ */
+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_fast_io_fail_timedout() - fast I/O failure timeout handler
+ * @work: Work structure used for scheduling this operation.
+ */
+static void rport_fast_io_fail_timedout(struct work_struct *work)
+{
+ struct srp_rport *rport = container_of(to_delayed_work(work),
+ struct srp_rport, fast_io_fail_work);
+ struct Scsi_Host *shost = rport_to_shost(rport);
+
+ pr_info("fast_io_fail_tmo expired for SRP %s / %s.\n",
+ dev_name(&rport->dev), dev_name(&shost->shost_gendev));
+
+ mutex_lock(&rport->mutex);
+ if (rport->state == SRP_RPORT_BLOCKED)
+ __rport_fail_io_fast(rport);
+ mutex_unlock(&rport->mutex);
+}
+
+/**
+ * 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 __srp_start_tl_fail_timers(struct srp_rport *rport)
+{
+ struct Scsi_Host *shost = rport_to_shost(rport);
+ int delay, fast_io_fail_tmo, dev_loss_tmo;
+
+ lockdep_assert_held(&rport->mutex);
+
+ delay = rport->reconnect_delay;
+ fast_io_fail_tmo = rport->fast_io_fail_tmo;
+ dev_loss_tmo = rport->dev_loss_tmo;
+ pr_debug("%s current state: %d\n", dev_name(&shost->shost_gendev),
+ rport->state);
+
+ if (rport->state == SRP_RPORT_LOST)
+ return;
+ if (delay > 0)
+ queue_delayed_work(system_long_wq, &rport->reconnect_work,
+ 1UL * delay * HZ);
+ if ((fast_io_fail_tmo >= 0 || dev_loss_tmo >= 0) &&
+ srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
+ pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
+ rport->state);
+ scsi_target_block(&shost->shost_gendev);
+ if (fast_io_fail_tmo >= 0)
+ queue_delayed_work(system_long_wq,
+ &rport->fast_io_fail_work,
+ 1UL * fast_io_fail_tmo * HZ);
+ if (dev_loss_tmo >= 0)
+ queue_delayed_work(system_long_wq,
+ &rport->dev_loss_work,
+ 1UL * dev_loss_tmo * HZ);
+ }
+}
+
+/**
+ * srp_start_tl_fail_timers() - start the transport layer failure timers
+ * @rport: SRP target port.
+ *
+ * Start the transport layer fast I/O failure and device loss timers. Do not
+ * modify a timer that was already started.
+ */
+void srp_start_tl_fail_timers(struct srp_rport *rport)
+{
+ mutex_lock(&rport->mutex);
+ __srp_start_tl_fail_timers(rport);
+ mutex_unlock(&rport->mutex);
+}
+EXPORT_SYMBOL(srp_start_tl_fail_timers);
+
+/**
+ * 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;
+ if (rport->state != SRP_RPORT_FAIL_FAST && rport->state != SRP_RPORT_LOST)
+ /*
+ * sdev state must be SDEV_TRANSPORT_OFFLINE, transition
+ * to SDEV_BLOCK is illegal. Calling scsi_target_unblock()
+ * later is ok though, scsi_internal_device_unblock_nowait()
+ * treats SDEV_TRANSPORT_OFFLINE like SDEV_BLOCK.
+ */
+ 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.
+ */
+ shost_for_each_device(sdev, shost) {
+ mutex_lock(&sdev->state_mutex);
+ if (sdev->sdev_state == SDEV_OFFLINE)
+ sdev->sdev_state = SDEV_RUNNING;
+ mutex_unlock(&sdev->state_mutex);
+ }
+ } else if (rport->state == SRP_RPORT_RUNNING) {
+ /*
+ * srp_reconnect_rport() has been invoked with fast_io_fail
+ * and dev_loss off. Mark the port as failed and start the TL
+ * failure timers if these had not yet been started.
+ */
+ __rport_fail_io_fast(rport);
+ __srp_start_tl_fail_timers(rport);
+ } else if (rport->state != SRP_RPORT_BLOCKED) {
+ scsi_target_unblock(&shost->shost_gendev,
+ SDEV_TRANSPORT_OFFLINE);
+ }
+ mutex_unlock(&rport->mutex);
+
+out:
+ return res;
+}
+EXPORT_SYMBOL(srp_reconnect_rport);
+
+/**
+ * srp_timed_out() - SRP transport intercept of the SCSI timeout EH
+ * @scmd: SCSI command.
+ *
+ * If a timeout occurs while an rport is in the blocked state, ask the SCSI
+ * EH to continue waiting (BLK_EH_RESET_TIMER). Otherwise let the SCSI core
+ * handle the timeout (BLK_EH_DONE).
+ *
+ * Note: This function is called from soft-IRQ context and with the request
+ * queue lock held.
+ */
+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 rport && 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_DONE;
+}
+EXPORT_SYMBOL(srp_timed_out);
+
+static void srp_rport_release(struct device *dev)
+{
+ struct srp_rport *rport = dev_to_rport(dev);
+
+ put_device(dev->parent);
+ kfree(rport);
+}
+
+static int scsi_is_srp_rport(const struct device *dev)
+{
+ return dev->release == srp_rport_release;
+}
+
+static int srp_rport_match(struct attribute_container *cont,
+ struct device *dev)
+{
+ struct Scsi_Host *shost;
+ struct srp_internal *i;
+
+ if (!scsi_is_srp_rport(dev))
+ return 0;
+
+ shost = dev_to_shost(dev->parent);
+ if (!shost->transportt)
+ return 0;
+ if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
+ return 0;
+
+ i = to_srp_internal(shost->transportt);
+ return &i->rport_attr_cont.ac == cont;
+}
+
+static int srp_host_match(struct attribute_container *cont, struct device *dev)
+{
+ struct Scsi_Host *shost;
+ struct srp_internal *i;
+
+ if (!scsi_is_host_device(dev))
+ return 0;
+
+ shost = dev_to_shost(dev);
+ if (!shost->transportt)
+ return 0;
+ if (shost->transportt->host_attrs.ac.class != &srp_host_class.class)
+ return 0;
+
+ i = to_srp_internal(shost->transportt);
+ return &i->t.host_attrs.ac == cont;
+}
+
+/**
+ * srp_rport_get() - increment rport reference count
+ * @rport: SRP target port.
+ */
+void srp_rport_get(struct srp_rport *rport)
+{
+ get_device(&rport->dev);
+}
+EXPORT_SYMBOL(srp_rport_get);
+
+/**
+ * srp_rport_put() - decrement rport reference count
+ * @rport: SRP target port.
+ */
+void srp_rport_put(struct srp_rport *rport)
+{
+ put_device(&rport->dev);
+}
+EXPORT_SYMBOL(srp_rport_put);
+
+/**
+ * srp_rport_add - add a SRP remote port to the device hierarchy
+ * @shost: scsi host the remote port is connected to.
+ * @ids: The port id for the remote port.
+ *
+ * Publishes a port to the rest of the system.
+ */
+struct srp_rport *srp_rport_add(struct Scsi_Host *shost,
+ struct srp_rport_identifiers *ids)
+{
+ struct srp_rport *rport;
+ struct device *parent = &shost->shost_gendev;
+ struct srp_internal *i = to_srp_internal(shost->transportt);
+ int id, ret;
+
+ rport = kzalloc(sizeof(*rport), GFP_KERNEL);
+ if (!rport)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&rport->mutex);
+
+ device_initialize(&rport->dev);
+
+ rport->dev.parent = get_device(parent);
+ rport->dev.release = srp_rport_release;
+
+ memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
+ rport->roles = ids->roles;
+
+ if (i->f->reconnect)
+ rport->reconnect_delay = i->f->reconnect_delay ?
+ *i->f->reconnect_delay : 10;
+ INIT_DELAYED_WORK(&rport->reconnect_work, srp_reconnect_work);
+ rport->fast_io_fail_tmo = i->f->fast_io_fail_tmo ?
+ *i->f->fast_io_fail_tmo : 15;
+ rport->dev_loss_tmo = i->f->dev_loss_tmo ? *i->f->dev_loss_tmo : 60;
+ INIT_DELAYED_WORK(&rport->fast_io_fail_work,
+ rport_fast_io_fail_timedout);
+ INIT_DELAYED_WORK(&rport->dev_loss_work, rport_dev_loss_timedout);
+
+ id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
+ dev_set_name(&rport->dev, "port-%d:%d", shost->host_no, id);
+
+ transport_setup_device(&rport->dev);
+
+ ret = device_add(&rport->dev);
+ if (ret) {
+ transport_destroy_device(&rport->dev);
+ put_device(&rport->dev);
+ return ERR_PTR(ret);
+ }
+
+ transport_add_device(&rport->dev);
+ transport_configure_device(&rport->dev);
+
+ return rport;
+}
+EXPORT_SYMBOL_GPL(srp_rport_add);
+
+/**
+ * srp_rport_del - remove a SRP remote port
+ * @rport: SRP remote port to remove
+ *
+ * Removes the specified SRP remote port.
+ */
+void srp_rport_del(struct srp_rport *rport)
+{
+ struct device *dev = &rport->dev;
+
+ transport_remove_device(dev);
+ device_del(dev);
+ transport_destroy_device(dev);
+
+ put_device(dev);
+}
+EXPORT_SYMBOL_GPL(srp_rport_del);
+
+static int do_srp_rport_del(struct device *dev, void *data)
+{
+ if (scsi_is_srp_rport(dev))
+ srp_rport_del(dev_to_rport(dev));
+ return 0;
+}
+
+/**
+ * srp_remove_host - tear down a Scsi_Host's SRP data structures
+ * @shost: Scsi Host that is torn down
+ *
+ * Removes all SRP remote ports for a given Scsi_Host.
+ * Must be called just before scsi_remove_host for SRP HBAs.
+ */
+void srp_remove_host(struct Scsi_Host *shost)
+{
+ device_for_each_child(&shost->shost_gendev, NULL, do_srp_rport_del);
+}
+EXPORT_SYMBOL_GPL(srp_remove_host);
+
+/**
+ * srp_stop_rport_timers - stop the transport layer recovery timers
+ * @rport: SRP remote port for which to stop the timers.
+ *
+ * Must be called after srp_remove_host() and scsi_remove_host(). The caller
+ * must hold a reference on the rport (rport->dev) and on the SCSI host
+ * (rport->dev.parent).
+ */
+void srp_stop_rport_timers(struct srp_rport *rport)
+{
+ mutex_lock(&rport->mutex);
+ if (rport->state == SRP_RPORT_BLOCKED)
+ __rport_fail_io_fast(rport);
+ srp_rport_set_state(rport, SRP_RPORT_LOST);
+ mutex_unlock(&rport->mutex);
+
+ cancel_delayed_work_sync(&rport->reconnect_work);
+ cancel_delayed_work_sync(&rport->fast_io_fail_work);
+ cancel_delayed_work_sync(&rport->dev_loss_work);
+}
+EXPORT_SYMBOL_GPL(srp_stop_rport_timers);
+
+/**
+ * srp_attach_transport - instantiate SRP transport template
+ * @ft: SRP transport class function template
+ */
+struct scsi_transport_template *
+srp_attach_transport(struct srp_function_template *ft)
+{
+ int count;
+ struct srp_internal *i;
+
+ i = kzalloc(sizeof(*i), GFP_KERNEL);
+ if (!i)
+ return NULL;
+
+ i->t.host_size = sizeof(struct srp_host_attrs);
+ i->t.host_attrs.ac.attrs = &i->host_attrs[0];
+ i->t.host_attrs.ac.class = &srp_host_class.class;
+ i->t.host_attrs.ac.match = srp_host_match;
+ i->host_attrs[0] = NULL;
+ transport_container_register(&i->t.host_attrs);
+
+ i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
+ i->rport_attr_cont.ac.class = &srp_rport_class.class;
+ i->rport_attr_cont.ac.match = srp_rport_match;
+
+ count = 0;
+ i->rport_attrs[count++] = &dev_attr_port_id;
+ i->rport_attrs[count++] = &dev_attr_roles;
+ if (ft->has_rport_state) {
+ i->rport_attrs[count++] = &dev_attr_state;
+ i->rport_attrs[count++] = &dev_attr_fast_io_fail_tmo;
+ i->rport_attrs[count++] = &dev_attr_dev_loss_tmo;
+ }
+ if (ft->reconnect) {
+ i->rport_attrs[count++] = &dev_attr_reconnect_delay;
+ i->rport_attrs[count++] = &dev_attr_failed_reconnects;
+ }
+ if (ft->rport_delete)
+ i->rport_attrs[count++] = &dev_attr_delete;
+ i->rport_attrs[count++] = NULL;
+ BUG_ON(count > ARRAY_SIZE(i->rport_attrs));
+
+ transport_container_register(&i->rport_attr_cont);
+
+ i->f = ft;
+
+ return &i->t;
+}
+EXPORT_SYMBOL_GPL(srp_attach_transport);
+
+/**
+ * srp_release_transport - release SRP transport template instance
+ * @t: transport template instance
+ */
+void srp_release_transport(struct scsi_transport_template *t)
+{
+ struct srp_internal *i = to_srp_internal(t);
+
+ transport_container_unregister(&i->t.host_attrs);
+ transport_container_unregister(&i->rport_attr_cont);
+
+ kfree(i);
+}
+EXPORT_SYMBOL_GPL(srp_release_transport);
+
+static __init int srp_transport_init(void)
+{
+ int ret;
+
+ ret = transport_class_register(&srp_host_class);
+ if (ret)
+ return ret;
+ ret = transport_class_register(&srp_rport_class);
+ if (ret)
+ goto unregister_host_class;
+
+ return 0;
+unregister_host_class:
+ transport_class_unregister(&srp_host_class);
+ return ret;
+}
+
+static void __exit srp_transport_exit(void)
+{
+ transport_class_unregister(&srp_host_class);
+ transport_class_unregister(&srp_rport_class);
+}
+
+MODULE_AUTHOR("FUJITA Tomonori");
+MODULE_DESCRIPTION("SRP Transport Attributes");
+MODULE_LICENSE("GPL");
+
+module_init(srp_transport_init);
+module_exit(srp_transport_exit);