RDS: Connection handling
While arguably the fact that the underlying transport needs a connection to convey RDS's datagrame reliably is not important to rds proper, the transports implemented so far (IB and TCP) have both been connection-oriented, and so the connection state machine-related code is in the common rds code. This patch also includes several work items, to handle connecting, sending, receiving, and shutdown. Signed-off-by: Andy Grover <andy.grover@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Andy Grover
David S. Miller
parent
a8c879a7ee
commit
00e0f34c61
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@ -0,0 +1,487 @@
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/*
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* Copyright (c) 2006 Oracle. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <net/inet_hashtables.h>
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#include "rds.h"
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#include "loop.h"
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#include "rdma.h"
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#define RDS_CONNECTION_HASH_BITS 12
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#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
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#define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1)
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/* converting this to RCU is a chore for another day.. */
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static DEFINE_SPINLOCK(rds_conn_lock);
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static unsigned long rds_conn_count;
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static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
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static struct kmem_cache *rds_conn_slab;
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static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
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{
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/* Pass NULL, don't need struct net for hash */
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unsigned long hash = inet_ehashfn(NULL,
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be32_to_cpu(laddr), 0,
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be32_to_cpu(faddr), 0);
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return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
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}
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#define rds_conn_info_set(var, test, suffix) do { \
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if (test) \
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var |= RDS_INFO_CONNECTION_FLAG_##suffix; \
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} while (0)
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static inline int rds_conn_is_sending(struct rds_connection *conn)
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{
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int ret = 0;
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if (!mutex_trylock(&conn->c_send_lock))
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ret = 1;
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else
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mutex_unlock(&conn->c_send_lock);
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return ret;
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}
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static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
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__be32 laddr, __be32 faddr,
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struct rds_transport *trans)
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{
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struct rds_connection *conn, *ret = NULL;
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struct hlist_node *pos;
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hlist_for_each_entry(conn, pos, head, c_hash_node) {
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if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
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conn->c_trans == trans) {
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ret = conn;
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break;
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}
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}
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rdsdebug("returning conn %p for %pI4 -> %pI4\n", ret,
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&laddr, &faddr);
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return ret;
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}
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/*
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* This is called by transports as they're bringing down a connection.
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* It clears partial message state so that the transport can start sending
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* and receiving over this connection again in the future. It is up to
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* the transport to have serialized this call with its send and recv.
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*/
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void rds_conn_reset(struct rds_connection *conn)
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{
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rdsdebug("connection %pI4 to %pI4 reset\n",
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&conn->c_laddr, &conn->c_faddr);
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rds_stats_inc(s_conn_reset);
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rds_send_reset(conn);
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conn->c_flags = 0;
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/* Do not clear next_rx_seq here, else we cannot distinguish
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* retransmitted packets from new packets, and will hand all
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* of them to the application. That is not consistent with the
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* reliability guarantees of RDS. */
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}
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/*
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* There is only every one 'conn' for a given pair of addresses in the
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* system at a time. They contain messages to be retransmitted and so
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* span the lifetime of the actual underlying transport connections.
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*
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* For now they are not garbage collected once they're created. They
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* are torn down as the module is removed, if ever.
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*/
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static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
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struct rds_transport *trans, gfp_t gfp,
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int is_outgoing)
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{
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struct rds_connection *conn, *tmp, *parent = NULL;
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struct hlist_head *head = rds_conn_bucket(laddr, faddr);
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unsigned long flags;
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int ret;
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spin_lock_irqsave(&rds_conn_lock, flags);
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conn = rds_conn_lookup(head, laddr, faddr, trans);
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if (conn
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&& conn->c_loopback
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&& conn->c_trans != &rds_loop_transport
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&& !is_outgoing) {
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/* This is a looped back IB connection, and we're
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* called by the code handling the incoming connect.
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* We need a second connection object into which we
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* can stick the other QP. */
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parent = conn;
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conn = parent->c_passive;
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}
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spin_unlock_irqrestore(&rds_conn_lock, flags);
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if (conn)
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goto out;
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conn = kmem_cache_alloc(rds_conn_slab, gfp);
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if (conn == NULL) {
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conn = ERR_PTR(-ENOMEM);
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goto out;
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}
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memset(conn, 0, sizeof(*conn));
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INIT_HLIST_NODE(&conn->c_hash_node);
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conn->c_version = RDS_PROTOCOL_3_0;
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conn->c_laddr = laddr;
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conn->c_faddr = faddr;
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spin_lock_init(&conn->c_lock);
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conn->c_next_tx_seq = 1;
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mutex_init(&conn->c_send_lock);
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INIT_LIST_HEAD(&conn->c_send_queue);
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INIT_LIST_HEAD(&conn->c_retrans);
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ret = rds_cong_get_maps(conn);
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if (ret) {
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kmem_cache_free(rds_conn_slab, conn);
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conn = ERR_PTR(ret);
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goto out;
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}
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/*
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* This is where a connection becomes loopback. If *any* RDS sockets
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* can bind to the destination address then we'd rather the messages
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* flow through loopback rather than either transport.
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*/
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if (rds_trans_get_preferred(faddr)) {
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conn->c_loopback = 1;
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if (is_outgoing && trans->t_prefer_loopback) {
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/* "outgoing" connection - and the transport
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* says it wants the connection handled by the
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* loopback transport. This is what TCP does.
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*/
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trans = &rds_loop_transport;
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}
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}
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conn->c_trans = trans;
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ret = trans->conn_alloc(conn, gfp);
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if (ret) {
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kmem_cache_free(rds_conn_slab, conn);
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conn = ERR_PTR(ret);
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goto out;
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}
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atomic_set(&conn->c_state, RDS_CONN_DOWN);
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conn->c_reconnect_jiffies = 0;
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INIT_DELAYED_WORK(&conn->c_send_w, rds_send_worker);
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INIT_DELAYED_WORK(&conn->c_recv_w, rds_recv_worker);
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INIT_DELAYED_WORK(&conn->c_conn_w, rds_connect_worker);
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INIT_WORK(&conn->c_down_w, rds_shutdown_worker);
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mutex_init(&conn->c_cm_lock);
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conn->c_flags = 0;
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rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n",
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conn, &laddr, &faddr,
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trans->t_name ? trans->t_name : "[unknown]",
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is_outgoing ? "(outgoing)" : "");
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spin_lock_irqsave(&rds_conn_lock, flags);
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if (parent == NULL) {
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tmp = rds_conn_lookup(head, laddr, faddr, trans);
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if (tmp == NULL)
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hlist_add_head(&conn->c_hash_node, head);
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} else {
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tmp = parent->c_passive;
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if (!tmp)
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parent->c_passive = conn;
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}
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if (tmp) {
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trans->conn_free(conn->c_transport_data);
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kmem_cache_free(rds_conn_slab, conn);
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conn = tmp;
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} else {
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rds_cong_add_conn(conn);
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rds_conn_count++;
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}
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spin_unlock_irqrestore(&rds_conn_lock, flags);
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out:
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return conn;
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}
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struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr,
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struct rds_transport *trans, gfp_t gfp)
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{
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return __rds_conn_create(laddr, faddr, trans, gfp, 0);
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}
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struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr,
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struct rds_transport *trans, gfp_t gfp)
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{
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return __rds_conn_create(laddr, faddr, trans, gfp, 1);
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}
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void rds_conn_destroy(struct rds_connection *conn)
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{
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struct rds_message *rm, *rtmp;
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rdsdebug("freeing conn %p for %pI4 -> "
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"%pI4\n", conn, &conn->c_laddr,
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&conn->c_faddr);
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hlist_del_init(&conn->c_hash_node);
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/* wait for the rds thread to shut it down */
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atomic_set(&conn->c_state, RDS_CONN_ERROR);
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cancel_delayed_work(&conn->c_conn_w);
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queue_work(rds_wq, &conn->c_down_w);
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flush_workqueue(rds_wq);
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/* tear down queued messages */
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list_for_each_entry_safe(rm, rtmp,
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&conn->c_send_queue,
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m_conn_item) {
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list_del_init(&rm->m_conn_item);
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BUG_ON(!list_empty(&rm->m_sock_item));
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rds_message_put(rm);
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}
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if (conn->c_xmit_rm)
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rds_message_put(conn->c_xmit_rm);
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conn->c_trans->conn_free(conn->c_transport_data);
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/*
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* The congestion maps aren't freed up here. They're
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* freed by rds_cong_exit() after all the connections
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* have been freed.
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*/
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rds_cong_remove_conn(conn);
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BUG_ON(!list_empty(&conn->c_retrans));
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kmem_cache_free(rds_conn_slab, conn);
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rds_conn_count--;
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}
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static void rds_conn_message_info(struct socket *sock, unsigned int len,
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struct rds_info_iterator *iter,
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struct rds_info_lengths *lens,
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int want_send)
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{
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struct hlist_head *head;
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struct hlist_node *pos;
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struct list_head *list;
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struct rds_connection *conn;
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struct rds_message *rm;
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unsigned long flags;
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unsigned int total = 0;
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size_t i;
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len /= sizeof(struct rds_info_message);
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spin_lock_irqsave(&rds_conn_lock, flags);
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for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
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i++, head++) {
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hlist_for_each_entry(conn, pos, head, c_hash_node) {
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if (want_send)
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list = &conn->c_send_queue;
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else
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list = &conn->c_retrans;
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spin_lock(&conn->c_lock);
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/* XXX too lazy to maintain counts.. */
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list_for_each_entry(rm, list, m_conn_item) {
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total++;
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if (total <= len)
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rds_inc_info_copy(&rm->m_inc, iter,
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conn->c_laddr,
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conn->c_faddr, 0);
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}
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spin_unlock(&conn->c_lock);
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}
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}
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spin_unlock_irqrestore(&rds_conn_lock, flags);
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lens->nr = total;
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lens->each = sizeof(struct rds_info_message);
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}
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static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
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struct rds_info_iterator *iter,
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struct rds_info_lengths *lens)
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{
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rds_conn_message_info(sock, len, iter, lens, 1);
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}
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static void rds_conn_message_info_retrans(struct socket *sock,
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unsigned int len,
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struct rds_info_iterator *iter,
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struct rds_info_lengths *lens)
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{
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rds_conn_message_info(sock, len, iter, lens, 0);
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}
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void rds_for_each_conn_info(struct socket *sock, unsigned int len,
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struct rds_info_iterator *iter,
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struct rds_info_lengths *lens,
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int (*visitor)(struct rds_connection *, void *),
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size_t item_len)
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{
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uint64_t buffer[(item_len + 7) / 8];
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struct hlist_head *head;
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struct hlist_node *pos;
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struct hlist_node *tmp;
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struct rds_connection *conn;
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unsigned long flags;
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size_t i;
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spin_lock_irqsave(&rds_conn_lock, flags);
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lens->nr = 0;
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lens->each = item_len;
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for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
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i++, head++) {
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hlist_for_each_entry_safe(conn, pos, tmp, head, c_hash_node) {
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/* XXX no c_lock usage.. */
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if (!visitor(conn, buffer))
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continue;
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/* We copy as much as we can fit in the buffer,
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* but we count all items so that the caller
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* can resize the buffer. */
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if (len >= item_len) {
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rds_info_copy(iter, buffer, item_len);
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len -= item_len;
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}
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lens->nr++;
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}
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}
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spin_unlock_irqrestore(&rds_conn_lock, flags);
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}
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static int rds_conn_info_visitor(struct rds_connection *conn,
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void *buffer)
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{
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struct rds_info_connection *cinfo = buffer;
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cinfo->next_tx_seq = conn->c_next_tx_seq;
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cinfo->next_rx_seq = conn->c_next_rx_seq;
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cinfo->laddr = conn->c_laddr;
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cinfo->faddr = conn->c_faddr;
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strncpy(cinfo->transport, conn->c_trans->t_name,
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sizeof(cinfo->transport));
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cinfo->flags = 0;
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rds_conn_info_set(cinfo->flags,
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rds_conn_is_sending(conn), SENDING);
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/* XXX Future: return the state rather than these funky bits */
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rds_conn_info_set(cinfo->flags,
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atomic_read(&conn->c_state) == RDS_CONN_CONNECTING,
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CONNECTING);
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rds_conn_info_set(cinfo->flags,
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atomic_read(&conn->c_state) == RDS_CONN_UP,
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CONNECTED);
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return 1;
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}
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static void rds_conn_info(struct socket *sock, unsigned int len,
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struct rds_info_iterator *iter,
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struct rds_info_lengths *lens)
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{
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rds_for_each_conn_info(sock, len, iter, lens,
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rds_conn_info_visitor,
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sizeof(struct rds_info_connection));
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}
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int __init rds_conn_init(void)
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{
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rds_conn_slab = kmem_cache_create("rds_connection",
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sizeof(struct rds_connection),
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0, 0, NULL);
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if (rds_conn_slab == NULL)
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return -ENOMEM;
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rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
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rds_info_register_func(RDS_INFO_SEND_MESSAGES,
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rds_conn_message_info_send);
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rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
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rds_conn_message_info_retrans);
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return 0;
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}
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void rds_conn_exit(void)
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{
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rds_loop_exit();
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WARN_ON(!hlist_empty(rds_conn_hash));
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kmem_cache_destroy(rds_conn_slab);
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rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
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||||
rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
|
||||
rds_conn_message_info_send);
|
||||
rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
|
||||
rds_conn_message_info_retrans);
|
||||
}
|
||||
|
||||
/*
|
||||
* Force a disconnect
|
||||
*/
|
||||
void rds_conn_drop(struct rds_connection *conn)
|
||||
{
|
||||
atomic_set(&conn->c_state, RDS_CONN_ERROR);
|
||||
queue_work(rds_wq, &conn->c_down_w);
|
||||
}
|
||||
|
||||
/*
|
||||
* An error occurred on the connection
|
||||
*/
|
||||
void
|
||||
__rds_conn_error(struct rds_connection *conn, const char *fmt, ...)
|
||||
{
|
||||
va_list ap;
|
||||
|
||||
va_start(ap, fmt);
|
||||
vprintk(fmt, ap);
|
||||
va_end(ap);
|
||||
|
||||
rds_conn_drop(conn);
|
||||
}
|
||||
|
|
@ -0,0 +1,265 @@
|
|||
/*
|
||||
* Copyright (c) 2006 Oracle. All rights reserved.
|
||||
*
|
||||
* This software is available to you under a choice of one of two
|
||||
* licenses. You may choose to be licensed under the terms of the GNU
|
||||
* General Public License (GPL) Version 2, available from the file
|
||||
* COPYING in the main directory of this source tree, or the
|
||||
* OpenIB.org BSD license below:
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or
|
||||
* without modification, are permitted provided that the following
|
||||
* conditions are met:
|
||||
*
|
||||
* - Redistributions of source code must retain the above
|
||||
* copyright notice, this list of conditions and the following
|
||||
* disclaimer.
|
||||
*
|
||||
* - Redistributions in binary form must reproduce the above
|
||||
* copyright notice, this list of conditions and the following
|
||||
* disclaimer in the documentation and/or other materials
|
||||
* provided with the distribution.
|
||||
*
|
||||
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
||||
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
||||
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
||||
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
||||
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
|
||||
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
||||
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
||||
* SOFTWARE.
|
||||
*
|
||||
*/
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/random.h>
|
||||
|
||||
#include "rds.h"
|
||||
|
||||
/*
|
||||
* All of connection management is simplified by serializing it through
|
||||
* work queues that execute in a connection managing thread.
|
||||
*
|
||||
* TCP wants to send acks through sendpage() in response to data_ready(),
|
||||
* but it needs a process context to do so.
|
||||
*
|
||||
* The receive paths need to allocate but can't drop packets (!) so we have
|
||||
* a thread around to block allocating if the receive fast path sees an
|
||||
* allocation failure.
|
||||
*/
|
||||
|
||||
/* Grand Unified Theory of connection life cycle:
|
||||
* At any point in time, the connection can be in one of these states:
|
||||
* DOWN, CONNECTING, UP, DISCONNECTING, ERROR
|
||||
*
|
||||
* The following transitions are possible:
|
||||
* ANY -> ERROR
|
||||
* UP -> DISCONNECTING
|
||||
* ERROR -> DISCONNECTING
|
||||
* DISCONNECTING -> DOWN
|
||||
* DOWN -> CONNECTING
|
||||
* CONNECTING -> UP
|
||||
*
|
||||
* Transition to state DISCONNECTING/DOWN:
|
||||
* - Inside the shutdown worker; synchronizes with xmit path
|
||||
* through c_send_lock, and with connection management callbacks
|
||||
* via c_cm_lock.
|
||||
*
|
||||
* For receive callbacks, we rely on the underlying transport
|
||||
* (TCP, IB/RDMA) to provide the necessary synchronisation.
|
||||
*/
|
||||
struct workqueue_struct *rds_wq;
|
||||
|
||||
void rds_connect_complete(struct rds_connection *conn)
|
||||
{
|
||||
if (!rds_conn_transition(conn, RDS_CONN_CONNECTING, RDS_CONN_UP)) {
|
||||
printk(KERN_WARNING "%s: Cannot transition to state UP, "
|
||||
"current state is %d\n",
|
||||
__func__,
|
||||
atomic_read(&conn->c_state));
|
||||
atomic_set(&conn->c_state, RDS_CONN_ERROR);
|
||||
queue_work(rds_wq, &conn->c_down_w);
|
||||
return;
|
||||
}
|
||||
|
||||
rdsdebug("conn %p for %pI4 to %pI4 complete\n",
|
||||
conn, &conn->c_laddr, &conn->c_faddr);
|
||||
|
||||
conn->c_reconnect_jiffies = 0;
|
||||
set_bit(0, &conn->c_map_queued);
|
||||
queue_delayed_work(rds_wq, &conn->c_send_w, 0);
|
||||
queue_delayed_work(rds_wq, &conn->c_recv_w, 0);
|
||||
}
|
||||
|
||||
/*
|
||||
* This random exponential backoff is relied on to eventually resolve racing
|
||||
* connects.
|
||||
*
|
||||
* If connect attempts race then both parties drop both connections and come
|
||||
* here to wait for a random amount of time before trying again. Eventually
|
||||
* the backoff range will be so much greater than the time it takes to
|
||||
* establish a connection that one of the pair will establish the connection
|
||||
* before the other's random delay fires.
|
||||
*
|
||||
* Connection attempts that arrive while a connection is already established
|
||||
* are also considered to be racing connects. This lets a connection from
|
||||
* a rebooted machine replace an existing stale connection before the transport
|
||||
* notices that the connection has failed.
|
||||
*
|
||||
* We should *always* start with a random backoff; otherwise a broken connection
|
||||
* will always take several iterations to be re-established.
|
||||
*/
|
||||
static void rds_queue_reconnect(struct rds_connection *conn)
|
||||
{
|
||||
unsigned long rand;
|
||||
|
||||
rdsdebug("conn %p for %pI4 to %pI4 reconnect jiffies %lu\n",
|
||||
conn, &conn->c_laddr, &conn->c_faddr,
|
||||
conn->c_reconnect_jiffies);
|
||||
|
||||
set_bit(RDS_RECONNECT_PENDING, &conn->c_flags);
|
||||
if (conn->c_reconnect_jiffies == 0) {
|
||||
conn->c_reconnect_jiffies = rds_sysctl_reconnect_min_jiffies;
|
||||
queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
|
||||
return;
|
||||
}
|
||||
|
||||
get_random_bytes(&rand, sizeof(rand));
|
||||
rdsdebug("%lu delay %lu ceil conn %p for %pI4 -> %pI4\n",
|
||||
rand % conn->c_reconnect_jiffies, conn->c_reconnect_jiffies,
|
||||
conn, &conn->c_laddr, &conn->c_faddr);
|
||||
queue_delayed_work(rds_wq, &conn->c_conn_w,
|
||||
rand % conn->c_reconnect_jiffies);
|
||||
|
||||
conn->c_reconnect_jiffies = min(conn->c_reconnect_jiffies * 2,
|
||||
rds_sysctl_reconnect_max_jiffies);
|
||||
}
|
||||
|
||||
void rds_connect_worker(struct work_struct *work)
|
||||
{
|
||||
struct rds_connection *conn = container_of(work, struct rds_connection, c_conn_w.work);
|
||||
int ret;
|
||||
|
||||
clear_bit(RDS_RECONNECT_PENDING, &conn->c_flags);
|
||||
if (rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
|
||||
ret = conn->c_trans->conn_connect(conn);
|
||||
rdsdebug("conn %p for %pI4 to %pI4 dispatched, ret %d\n",
|
||||
conn, &conn->c_laddr, &conn->c_faddr, ret);
|
||||
|
||||
if (ret) {
|
||||
if (rds_conn_transition(conn, RDS_CONN_CONNECTING, RDS_CONN_DOWN))
|
||||
rds_queue_reconnect(conn);
|
||||
else
|
||||
rds_conn_error(conn, "RDS: connect failed\n");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void rds_shutdown_worker(struct work_struct *work)
|
||||
{
|
||||
struct rds_connection *conn = container_of(work, struct rds_connection, c_down_w);
|
||||
|
||||
/* 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);
|
||||
|
||||
mutex_lock(&conn->c_send_lock);
|
||||
conn->c_trans->conn_shutdown(conn);
|
||||
rds_conn_reset(conn);
|
||||
mutex_unlock(&conn->c_send_lock);
|
||||
|
||||
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(&conn->c_conn_w);
|
||||
if (!hlist_unhashed(&conn->c_hash_node))
|
||||
rds_queue_reconnect(conn);
|
||||
}
|
||||
|
||||
void rds_send_worker(struct work_struct *work)
|
||||
{
|
||||
struct rds_connection *conn = container_of(work, struct rds_connection, c_send_w.work);
|
||||
int ret;
|
||||
|
||||
if (rds_conn_state(conn) == RDS_CONN_UP) {
|
||||
ret = rds_send_xmit(conn);
|
||||
rdsdebug("conn %p ret %d\n", conn, ret);
|
||||
switch (ret) {
|
||||
case -EAGAIN:
|
||||
rds_stats_inc(s_send_immediate_retry);
|
||||
queue_delayed_work(rds_wq, &conn->c_send_w, 0);
|
||||
break;
|
||||
case -ENOMEM:
|
||||
rds_stats_inc(s_send_delayed_retry);
|
||||
queue_delayed_work(rds_wq, &conn->c_send_w, 2);
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void rds_recv_worker(struct work_struct *work)
|
||||
{
|
||||
struct rds_connection *conn = container_of(work, struct rds_connection, c_recv_w.work);
|
||||
int ret;
|
||||
|
||||
if (rds_conn_state(conn) == RDS_CONN_UP) {
|
||||
ret = conn->c_trans->recv(conn);
|
||||
rdsdebug("conn %p ret %d\n", conn, ret);
|
||||
switch (ret) {
|
||||
case -EAGAIN:
|
||||
rds_stats_inc(s_recv_immediate_retry);
|
||||
queue_delayed_work(rds_wq, &conn->c_recv_w, 0);
|
||||
break;
|
||||
case -ENOMEM:
|
||||
rds_stats_inc(s_recv_delayed_retry);
|
||||
queue_delayed_work(rds_wq, &conn->c_recv_w, 2);
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void rds_threads_exit(void)
|
||||
{
|
||||
destroy_workqueue(rds_wq);
|
||||
}
|
||||
|
||||
int __init rds_threads_init(void)
|
||||
{
|
||||
rds_wq = create_singlethread_workqueue("krdsd");
|
||||
if (rds_wq == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
return 0;
|
||||
}
|
||||
Loading…
Reference in New Issue