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path: root/drivers/scsi/scsi_transport_iscsi.c
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Diffstat (limited to 'drivers/scsi/scsi_transport_iscsi.c')
-rw-r--r--drivers/scsi/scsi_transport_iscsi.c239
1 files changed, 140 insertions, 99 deletions
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 27951ea05dd4..2c0dd64159b0 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -86,6 +86,9 @@ struct iscsi_internal {
struct transport_container session_cont;
};
+static DEFINE_IDR(iscsi_ep_idr);
+static DEFINE_MUTEX(iscsi_ep_idr_mutex);
+
static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
static struct workqueue_struct *iscsi_conn_cleanup_workq;
@@ -168,6 +171,11 @@ struct device_attribute dev_attr_##_prefix##_##_name = \
static void iscsi_endpoint_release(struct device *dev)
{
struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
+
+ mutex_lock(&iscsi_ep_idr_mutex);
+ idr_remove(&iscsi_ep_idr, ep->id);
+ mutex_unlock(&iscsi_ep_idr_mutex);
+
kfree(ep);
}
@@ -180,7 +188,7 @@ static ssize_t
show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
{
struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
- return sysfs_emit(buf, "%llu\n", (unsigned long long) ep->id);
+ return sysfs_emit(buf, "%d\n", ep->id);
}
static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);
@@ -193,48 +201,32 @@ static struct attribute_group iscsi_endpoint_group = {
.attrs = iscsi_endpoint_attrs,
};
-#define ISCSI_MAX_EPID -1
-
-static int iscsi_match_epid(struct device *dev, const void *data)
-{
- struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
- const uint64_t *epid = data;
-
- return *epid == ep->id;
-}
-
struct iscsi_endpoint *
iscsi_create_endpoint(int dd_size)
{
- struct device *dev;
struct iscsi_endpoint *ep;
- uint64_t id;
- int err;
-
- for (id = 1; id < ISCSI_MAX_EPID; id++) {
- dev = class_find_device(&iscsi_endpoint_class, NULL, &id,
- iscsi_match_epid);
- if (!dev)
- break;
- else
- put_device(dev);
- }
- if (id == ISCSI_MAX_EPID) {
- printk(KERN_ERR "Too many connections. Max supported %u\n",
- ISCSI_MAX_EPID - 1);
- return NULL;
- }
+ int err, id;
ep = kzalloc(sizeof(*ep) + dd_size, GFP_KERNEL);
if (!ep)
return NULL;
+ mutex_lock(&iscsi_ep_idr_mutex);
+ id = idr_alloc(&iscsi_ep_idr, ep, 0, -1, GFP_NOIO);
+ if (id < 0) {
+ mutex_unlock(&iscsi_ep_idr_mutex);
+ printk(KERN_ERR "Could not allocate endpoint ID. Error %d.\n",
+ id);
+ goto free_ep;
+ }
+ mutex_unlock(&iscsi_ep_idr_mutex);
+
ep->id = id;
ep->dev.class = &iscsi_endpoint_class;
- dev_set_name(&ep->dev, "ep-%llu", (unsigned long long) id);
+ dev_set_name(&ep->dev, "ep-%d", id);
err = device_register(&ep->dev);
if (err)
- goto free_ep;
+ goto free_id;
err = sysfs_create_group(&ep->dev.kobj, &iscsi_endpoint_group);
if (err)
@@ -248,6 +240,10 @@ unregister_dev:
device_unregister(&ep->dev);
return NULL;
+free_id:
+ mutex_lock(&iscsi_ep_idr_mutex);
+ idr_remove(&iscsi_ep_idr, id);
+ mutex_unlock(&iscsi_ep_idr_mutex);
free_ep:
kfree(ep);
return NULL;
@@ -275,14 +271,17 @@ EXPORT_SYMBOL_GPL(iscsi_put_endpoint);
*/
struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle)
{
- struct device *dev;
+ struct iscsi_endpoint *ep;
- dev = class_find_device(&iscsi_endpoint_class, NULL, &handle,
- iscsi_match_epid);
- if (!dev)
- return NULL;
+ mutex_lock(&iscsi_ep_idr_mutex);
+ ep = idr_find(&iscsi_ep_idr, handle);
+ if (!ep)
+ goto unlock;
- return iscsi_dev_to_endpoint(dev);
+ get_device(&ep->dev);
+unlock:
+ mutex_unlock(&iscsi_ep_idr_mutex);
+ return ep;
}
EXPORT_SYMBOL_GPL(iscsi_lookup_endpoint);
@@ -2202,10 +2201,10 @@ static void iscsi_stop_conn(struct iscsi_cls_conn *conn, int flag)
switch (flag) {
case STOP_CONN_RECOVER:
- conn->state = ISCSI_CONN_FAILED;
+ WRITE_ONCE(conn->state, ISCSI_CONN_FAILED);
break;
case STOP_CONN_TERM:
- conn->state = ISCSI_CONN_DOWN;
+ WRITE_ONCE(conn->state, ISCSI_CONN_DOWN);
break;
default:
iscsi_cls_conn_printk(KERN_ERR, conn, "invalid stop flag %d\n",
@@ -2217,6 +2216,49 @@ static void iscsi_stop_conn(struct iscsi_cls_conn *conn, int flag)
ISCSI_DBG_TRANS_CONN(conn, "Stopping conn done.\n");
}
+static void iscsi_ep_disconnect(struct iscsi_cls_conn *conn, bool is_active)
+{
+ struct iscsi_cls_session *session = iscsi_conn_to_session(conn);
+ struct iscsi_endpoint *ep;
+
+ ISCSI_DBG_TRANS_CONN(conn, "disconnect ep.\n");
+ WRITE_ONCE(conn->state, ISCSI_CONN_FAILED);
+
+ if (!conn->ep || !session->transport->ep_disconnect)
+ return;
+
+ ep = conn->ep;
+ conn->ep = NULL;
+
+ session->transport->unbind_conn(conn, is_active);
+ session->transport->ep_disconnect(ep);
+ ISCSI_DBG_TRANS_CONN(conn, "disconnect ep done.\n");
+}
+
+static void iscsi_if_disconnect_bound_ep(struct iscsi_cls_conn *conn,
+ struct iscsi_endpoint *ep,
+ bool is_active)
+{
+ /* Check if this was a conn error and the kernel took ownership */
+ spin_lock_irq(&conn->lock);
+ if (!test_bit(ISCSI_CLS_CONN_BIT_CLEANUP, &conn->flags)) {
+ spin_unlock_irq(&conn->lock);
+ iscsi_ep_disconnect(conn, is_active);
+ } else {
+ spin_unlock_irq(&conn->lock);
+ ISCSI_DBG_TRANS_CONN(conn, "flush kernel conn cleanup.\n");
+ mutex_unlock(&conn->ep_mutex);
+
+ flush_work(&conn->cleanup_work);
+ /*
+ * Userspace is now done with the EP so we can release the ref
+ * iscsi_cleanup_conn_work_fn took.
+ */
+ iscsi_put_endpoint(ep);
+ mutex_lock(&conn->ep_mutex);
+ }
+}
+
static int iscsi_if_stop_conn(struct iscsi_transport *transport,
struct iscsi_uevent *ev)
{
@@ -2238,11 +2280,24 @@ static int iscsi_if_stop_conn(struct iscsi_transport *transport,
iscsi_stop_conn(conn, flag);
} else {
/*
+ * For offload, when iscsid is restarted it won't know about
+ * existing endpoints so it can't do a ep_disconnect. We clean
+ * it up here for userspace.
+ */
+ mutex_lock(&conn->ep_mutex);
+ if (conn->ep)
+ iscsi_if_disconnect_bound_ep(conn, conn->ep, true);
+ mutex_unlock(&conn->ep_mutex);
+
+ /*
* Figure out if it was the kernel or userspace initiating this.
*/
+ spin_lock_irq(&conn->lock);
if (!test_and_set_bit(ISCSI_CLS_CONN_BIT_CLEANUP, &conn->flags)) {
+ spin_unlock_irq(&conn->lock);
iscsi_stop_conn(conn, flag);
} else {
+ spin_unlock_irq(&conn->lock);
ISCSI_DBG_TRANS_CONN(conn,
"flush kernel conn cleanup.\n");
flush_work(&conn->cleanup_work);
@@ -2251,31 +2306,14 @@ static int iscsi_if_stop_conn(struct iscsi_transport *transport,
* Only clear for recovery to avoid extra cleanup runs during
* termination.
*/
+ spin_lock_irq(&conn->lock);
clear_bit(ISCSI_CLS_CONN_BIT_CLEANUP, &conn->flags);
+ spin_unlock_irq(&conn->lock);
}
ISCSI_DBG_TRANS_CONN(conn, "iscsi if conn stop done.\n");
return 0;
}
-static void iscsi_ep_disconnect(struct iscsi_cls_conn *conn, bool is_active)
-{
- struct iscsi_cls_session *session = iscsi_conn_to_session(conn);
- struct iscsi_endpoint *ep;
-
- ISCSI_DBG_TRANS_CONN(conn, "disconnect ep.\n");
- conn->state = ISCSI_CONN_FAILED;
-
- if (!conn->ep || !session->transport->ep_disconnect)
- return;
-
- ep = conn->ep;
- conn->ep = NULL;
-
- session->transport->unbind_conn(conn, is_active);
- session->transport->ep_disconnect(ep);
- ISCSI_DBG_TRANS_CONN(conn, "disconnect ep done.\n");
-}
-
static void iscsi_cleanup_conn_work_fn(struct work_struct *work)
{
struct iscsi_cls_conn *conn = container_of(work, struct iscsi_cls_conn,
@@ -2284,18 +2322,11 @@ static void iscsi_cleanup_conn_work_fn(struct work_struct *work)
mutex_lock(&conn->ep_mutex);
/*
- * If we are not at least bound there is nothing for us to do. Userspace
- * will do a ep_disconnect call if offload is used, but will not be
- * doing a stop since there is nothing to clean up, so we have to clear
- * the cleanup bit here.
+ * Get a ref to the ep, so we don't release its ID until after
+ * userspace is done referencing it in iscsi_if_disconnect_bound_ep.
*/
- if (conn->state != ISCSI_CONN_BOUND && conn->state != ISCSI_CONN_UP) {
- ISCSI_DBG_TRANS_CONN(conn, "Got error while conn is already failed. Ignoring.\n");
- clear_bit(ISCSI_CLS_CONN_BIT_CLEANUP, &conn->flags);
- mutex_unlock(&conn->ep_mutex);
- return;
- }
-
+ if (conn->ep)
+ get_device(&conn->ep->dev);
iscsi_ep_disconnect(conn, false);
if (system_state != SYSTEM_RUNNING) {
@@ -2340,11 +2371,12 @@ iscsi_alloc_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
conn->dd_data = &conn[1];
mutex_init(&conn->ep_mutex);
+ spin_lock_init(&conn->lock);
INIT_LIST_HEAD(&conn->conn_list);
INIT_WORK(&conn->cleanup_work, iscsi_cleanup_conn_work_fn);
conn->transport = transport;
conn->cid = cid;
- conn->state = ISCSI_CONN_DOWN;
+ WRITE_ONCE(conn->state, ISCSI_CONN_DOWN);
/* this is released in the dev's release function */
if (!get_device(&session->dev))
@@ -2542,9 +2574,32 @@ void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
struct iscsi_uevent *ev;
struct iscsi_internal *priv;
int len = nlmsg_total_size(sizeof(*ev));
+ unsigned long flags;
+ int state;
- if (!test_and_set_bit(ISCSI_CLS_CONN_BIT_CLEANUP, &conn->flags))
- queue_work(iscsi_conn_cleanup_workq, &conn->cleanup_work);
+ spin_lock_irqsave(&conn->lock, flags);
+ /*
+ * Userspace will only do a stop call if we are at least bound. And, we
+ * only need to do the in kernel cleanup if in the UP state so cmds can
+ * be released to upper layers. If in other states just wait for
+ * userspace to avoid races that can leave the cleanup_work queued.
+ */
+ state = READ_ONCE(conn->state);
+ switch (state) {
+ case ISCSI_CONN_BOUND:
+ case ISCSI_CONN_UP:
+ if (!test_and_set_bit(ISCSI_CLS_CONN_BIT_CLEANUP,
+ &conn->flags)) {
+ queue_work(iscsi_conn_cleanup_workq,
+ &conn->cleanup_work);
+ }
+ break;
+ default:
+ ISCSI_DBG_TRANS_CONN(conn, "Got conn error in state %d\n",
+ state);
+ break;
+ }
+ spin_unlock_irqrestore(&conn->lock, flags);
priv = iscsi_if_transport_lookup(conn->transport);
if (!priv)
@@ -2894,7 +2949,7 @@ iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
char *data = (char*)ev + sizeof(*ev);
struct iscsi_cls_conn *conn;
struct iscsi_cls_session *session;
- int err = 0, value = 0;
+ int err = 0, value = 0, state;
if (ev->u.set_param.len > PAGE_SIZE)
return -EINVAL;
@@ -2911,8 +2966,8 @@ iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
session->recovery_tmo = value;
break;
default:
- if ((conn->state == ISCSI_CONN_BOUND) ||
- (conn->state == ISCSI_CONN_UP)) {
+ state = READ_ONCE(conn->state);
+ if (state == ISCSI_CONN_BOUND || state == ISCSI_CONN_UP) {
err = transport->set_param(conn, ev->u.set_param.param,
data, ev->u.set_param.len);
} else {
@@ -2984,16 +3039,7 @@ static int iscsi_if_ep_disconnect(struct iscsi_transport *transport,
}
mutex_lock(&conn->ep_mutex);
- /* Check if this was a conn error and the kernel took ownership */
- if (test_bit(ISCSI_CLS_CONN_BIT_CLEANUP, &conn->flags)) {
- ISCSI_DBG_TRANS_CONN(conn, "flush kernel conn cleanup.\n");
- mutex_unlock(&conn->ep_mutex);
-
- flush_work(&conn->cleanup_work);
- goto put_ep;
- }
-
- iscsi_ep_disconnect(conn, false);
+ iscsi_if_disconnect_bound_ep(conn, ep, false);
mutex_unlock(&conn->ep_mutex);
put_ep:
iscsi_put_endpoint(ep);
@@ -3696,24 +3742,17 @@ static int iscsi_if_transport_conn(struct iscsi_transport *transport,
return -EINVAL;
mutex_lock(&conn->ep_mutex);
+ spin_lock_irq(&conn->lock);
if (test_bit(ISCSI_CLS_CONN_BIT_CLEANUP, &conn->flags)) {
+ spin_unlock_irq(&conn->lock);
mutex_unlock(&conn->ep_mutex);
ev->r.retcode = -ENOTCONN;
return 0;
}
+ spin_unlock_irq(&conn->lock);
switch (nlh->nlmsg_type) {
case ISCSI_UEVENT_BIND_CONN:
- if (conn->ep) {
- /*
- * For offload boot support where iscsid is restarted
- * during the pivot root stage, the ep will be intact
- * here when the new iscsid instance starts up and
- * reconnects.
- */
- iscsi_ep_disconnect(conn, true);
- }
-
session = iscsi_session_lookup(ev->u.b_conn.sid);
if (!session) {
err = -EINVAL;
@@ -3724,7 +3763,7 @@ static int iscsi_if_transport_conn(struct iscsi_transport *transport,
ev->u.b_conn.transport_eph,
ev->u.b_conn.is_leading);
if (!ev->r.retcode)
- conn->state = ISCSI_CONN_BOUND;
+ WRITE_ONCE(conn->state, ISCSI_CONN_BOUND);
if (ev->r.retcode || !transport->ep_connect)
break;
@@ -3743,7 +3782,8 @@ static int iscsi_if_transport_conn(struct iscsi_transport *transport,
case ISCSI_UEVENT_START_CONN:
ev->r.retcode = transport->start_conn(conn);
if (!ev->r.retcode)
- conn->state = ISCSI_CONN_UP;
+ WRITE_ONCE(conn->state, ISCSI_CONN_UP);
+
break;
case ISCSI_UEVENT_SEND_PDU:
pdu_len = nlh->nlmsg_len - sizeof(*nlh) - sizeof(*ev);
@@ -4050,10 +4090,11 @@ static ssize_t show_conn_state(struct device *dev,
{
struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);
const char *state = "unknown";
+ int conn_state = READ_ONCE(conn->state);
- if (conn->state >= 0 &&
- conn->state < ARRAY_SIZE(connection_state_names))
- state = connection_state_names[conn->state];
+ if (conn_state >= 0 &&
+ conn_state < ARRAY_SIZE(connection_state_names))
+ state = connection_state_names[conn_state];
return sysfs_emit(buf, "%s\n", state);
}