#include "rds.h"
#include "loop.h"
-#include "rdma.h"
#define RDS_CONNECTION_HASH_BITS 12
#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
var |= RDS_INFO_CONNECTION_FLAG_##suffix; \
} while (0)
-static inline int rds_conn_is_sending(struct rds_connection *conn)
-{
- int ret = 0;
-
- if (!mutex_trylock(&conn->c_send_lock))
- ret = 1;
- else
- mutex_unlock(&conn->c_send_lock);
-
- return ret;
-}
-
+/* rcu read lock must be held or the connection spinlock */
static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
__be32 laddr, __be32 faddr,
struct rds_transport *trans)
struct rds_connection *conn, *ret = NULL;
struct hlist_node *pos;
- hlist_for_each_entry(conn, pos, head, c_hash_node) {
+ hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
conn->c_trans == trans) {
ret = conn;
unsigned long flags;
int ret;
- spin_lock_irqsave(&rds_conn_lock, flags);
+
+ rcu_read_lock();
conn = rds_conn_lookup(head, laddr, faddr, trans);
if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
!is_outgoing) {
parent = conn;
conn = parent->c_passive;
}
- spin_unlock_irqrestore(&rds_conn_lock, flags);
+ rcu_read_unlock();
if (conn)
goto out;
conn = kmem_cache_zalloc(rds_conn_slab, gfp);
- if (conn == NULL) {
+ if (!conn) {
conn = ERR_PTR(-ENOMEM);
goto out;
}
spin_lock_init(&conn->c_lock);
conn->c_next_tx_seq = 1;
- mutex_init(&conn->c_send_lock);
+ spin_lock_init(&conn->c_send_lock);
+ atomic_set(&conn->c_send_generation, 1);
+ atomic_set(&conn->c_senders, 0);
INIT_LIST_HEAD(&conn->c_send_queue);
INIT_LIST_HEAD(&conn->c_retrans);
kmem_cache_free(rds_conn_slab, conn);
conn = found;
} else {
- hlist_add_head(&conn->c_hash_node, head);
+ hlist_add_head_rcu(&conn->c_hash_node, head);
rds_cong_add_conn(conn);
rds_conn_count++;
}
}
EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
+void rds_conn_shutdown(struct rds_connection *conn)
+{
+ /* shut it down unless it's down already */
+ if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
+ /*
+ * Quiesce the connection mgmt handlers before we start tearing
+ * things down. We don't hold the mutex for the entire
+ * duration of the shutdown operation, else we may be
+ * deadlocking with the CM handler. Instead, the CM event
+ * handler is supposed to check for state DISCONNECTING
+ */
+ mutex_lock(&conn->c_cm_lock);
+ if (!rds_conn_transition(conn, RDS_CONN_UP, RDS_CONN_DISCONNECTING)
+ && !rds_conn_transition(conn, RDS_CONN_ERROR, RDS_CONN_DISCONNECTING)) {
+ rds_conn_error(conn, "shutdown called in state %d\n",
+ atomic_read(&conn->c_state));
+ mutex_unlock(&conn->c_cm_lock);
+ return;
+ }
+ mutex_unlock(&conn->c_cm_lock);
+
+ /* verify everybody's out of rds_send_xmit() */
+ spin_lock_irq(&conn->c_send_lock);
+ spin_unlock_irq(&conn->c_send_lock);
+
+ while(atomic_read(&conn->c_senders)) {
+ schedule_timeout(1);
+ spin_lock_irq(&conn->c_send_lock);
+ spin_unlock_irq(&conn->c_send_lock);
+ }
+
+ conn->c_trans->conn_shutdown(conn);
+ rds_conn_reset(conn);
+
+ if (!rds_conn_transition(conn, RDS_CONN_DISCONNECTING, RDS_CONN_DOWN)) {
+ /* This can happen - eg when we're in the middle of tearing
+ * down the connection, and someone unloads the rds module.
+ * Quite reproduceable with loopback connections.
+ * Mostly harmless.
+ */
+ rds_conn_error(conn,
+ "%s: failed to transition to state DOWN, "
+ "current state is %d\n",
+ __func__,
+ atomic_read(&conn->c_state));
+ return;
+ }
+ }
+
+ /* Then reconnect if it's still live.
+ * The passive side of an IB loopback connection is never added
+ * to the conn hash, so we never trigger a reconnect on this
+ * conn - the reconnect is always triggered by the active peer. */
+ cancel_delayed_work_sync(&conn->c_conn_w);
+ rcu_read_lock();
+ if (!hlist_unhashed(&conn->c_hash_node)) {
+ rcu_read_unlock();
+ rds_queue_reconnect(conn);
+ } else {
+ rcu_read_unlock();
+ }
+}
+
+/*
+ * Stop and free a connection.
+ */
void rds_conn_destroy(struct rds_connection *conn)
{
struct rds_message *rm, *rtmp;
"%pI4\n", conn, &conn->c_laddr,
&conn->c_faddr);
- hlist_del_init(&conn->c_hash_node);
+ /* Ensure conn will not be scheduled for reconnect */
+ spin_lock_irq(&rds_conn_lock);
+ hlist_del_init_rcu(&conn->c_hash_node);
+ spin_unlock_irq(&rds_conn_lock);
- /* wait for the rds thread to shut it down */
- atomic_set(&conn->c_state, RDS_CONN_ERROR);
- cancel_delayed_work(&conn->c_conn_w);
- queue_work(rds_wq, &conn->c_down_w);
- flush_workqueue(rds_wq);
+ synchronize_rcu();
+
+ rds_conn_shutdown(conn);
/* tear down queued messages */
list_for_each_entry_safe(rm, rtmp,
struct list_head *list;
struct rds_connection *conn;
struct rds_message *rm;
- unsigned long flags;
unsigned int total = 0;
size_t i;
len /= sizeof(struct rds_info_message);
- spin_lock_irqsave(&rds_conn_lock, flags);
+ rcu_read_lock();
for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
i++, head++) {
- hlist_for_each_entry(conn, pos, head, c_hash_node) {
+ hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
if (want_send)
list = &conn->c_send_queue;
else
spin_unlock(&conn->c_lock);
}
}
-
- spin_unlock_irqrestore(&rds_conn_lock, flags);
+ rcu_read_unlock();
lens->nr = total;
lens->each = sizeof(struct rds_info_message);
uint64_t buffer[(item_len + 7) / 8];
struct hlist_head *head;
struct hlist_node *pos;
- struct hlist_node *tmp;
struct rds_connection *conn;
- unsigned long flags;
size_t i;
- spin_lock_irqsave(&rds_conn_lock, flags);
+ rcu_read_lock();
lens->nr = 0;
lens->each = item_len;
for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
i++, head++) {
- hlist_for_each_entry_safe(conn, pos, tmp, head, c_hash_node) {
+ hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
/* XXX no c_lock usage.. */
if (!visitor(conn, buffer))
lens->nr++;
}
}
-
- spin_unlock_irqrestore(&rds_conn_lock, flags);
+ rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
cinfo->flags = 0;
rds_conn_info_set(cinfo->flags,
- rds_conn_is_sending(conn), SENDING);
+ spin_is_locked(&conn->c_send_lock), SENDING);
/* XXX Future: return the state rather than these funky bits */
rds_conn_info_set(cinfo->flags,
atomic_read(&conn->c_state) == RDS_CONN_CONNECTING,
rds_conn_slab = kmem_cache_create("rds_connection",
sizeof(struct rds_connection),
0, 0, NULL);
- if (rds_conn_slab == NULL)
+ if (!rds_conn_slab)
return -ENOMEM;
rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
projects / mv-sheeva.git / blobdiff