forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
311 lines
8.8 KiB
311 lines
8.8 KiB
/* |
|
* Copyright (c) 2006, 2018 Oracle and/or its affiliates. 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 <linux/export.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 RDS_IN_XMIT, 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; |
|
EXPORT_SYMBOL_GPL(rds_wq); |
|
|
|
void rds_connect_path_complete(struct rds_conn_path *cp, int curr) |
|
{ |
|
if (!rds_conn_path_transition(cp, curr, RDS_CONN_UP)) { |
|
printk(KERN_WARNING "%s: Cannot transition to state UP, " |
|
"current state is %d\n", |
|
__func__, |
|
atomic_read(&cp->cp_state)); |
|
rds_conn_path_drop(cp, false); |
|
return; |
|
} |
|
|
|
rdsdebug("conn %p for %pI6c to %pI6c complete\n", |
|
cp->cp_conn, &cp->cp_conn->c_laddr, &cp->cp_conn->c_faddr); |
|
|
|
cp->cp_reconnect_jiffies = 0; |
|
set_bit(0, &cp->cp_conn->c_map_queued); |
|
rcu_read_lock(); |
|
if (!rds_destroy_pending(cp->cp_conn)) { |
|
queue_delayed_work(rds_wq, &cp->cp_send_w, 0); |
|
queue_delayed_work(rds_wq, &cp->cp_recv_w, 0); |
|
} |
|
rcu_read_unlock(); |
|
cp->cp_conn->c_proposed_version = RDS_PROTOCOL_VERSION; |
|
} |
|
EXPORT_SYMBOL_GPL(rds_connect_path_complete); |
|
|
|
void rds_connect_complete(struct rds_connection *conn) |
|
{ |
|
rds_connect_path_complete(&conn->c_path[0], RDS_CONN_CONNECTING); |
|
} |
|
EXPORT_SYMBOL_GPL(rds_connect_complete); |
|
|
|
/* |
|
* 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. |
|
*/ |
|
void rds_queue_reconnect(struct rds_conn_path *cp) |
|
{ |
|
unsigned long rand; |
|
struct rds_connection *conn = cp->cp_conn; |
|
|
|
rdsdebug("conn %p for %pI6c to %pI6c reconnect jiffies %lu\n", |
|
conn, &conn->c_laddr, &conn->c_faddr, |
|
cp->cp_reconnect_jiffies); |
|
|
|
/* let peer with smaller addr initiate reconnect, to avoid duels */ |
|
if (conn->c_trans->t_type == RDS_TRANS_TCP && |
|
rds_addr_cmp(&conn->c_laddr, &conn->c_faddr) >= 0) |
|
return; |
|
|
|
set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags); |
|
if (cp->cp_reconnect_jiffies == 0) { |
|
cp->cp_reconnect_jiffies = rds_sysctl_reconnect_min_jiffies; |
|
rcu_read_lock(); |
|
if (!rds_destroy_pending(cp->cp_conn)) |
|
queue_delayed_work(rds_wq, &cp->cp_conn_w, 0); |
|
rcu_read_unlock(); |
|
return; |
|
} |
|
|
|
get_random_bytes(&rand, sizeof(rand)); |
|
rdsdebug("%lu delay %lu ceil conn %p for %pI6c -> %pI6c\n", |
|
rand % cp->cp_reconnect_jiffies, cp->cp_reconnect_jiffies, |
|
conn, &conn->c_laddr, &conn->c_faddr); |
|
rcu_read_lock(); |
|
if (!rds_destroy_pending(cp->cp_conn)) |
|
queue_delayed_work(rds_wq, &cp->cp_conn_w, |
|
rand % cp->cp_reconnect_jiffies); |
|
rcu_read_unlock(); |
|
|
|
cp->cp_reconnect_jiffies = min(cp->cp_reconnect_jiffies * 2, |
|
rds_sysctl_reconnect_max_jiffies); |
|
} |
|
|
|
void rds_connect_worker(struct work_struct *work) |
|
{ |
|
struct rds_conn_path *cp = container_of(work, |
|
struct rds_conn_path, |
|
cp_conn_w.work); |
|
struct rds_connection *conn = cp->cp_conn; |
|
int ret; |
|
|
|
if (cp->cp_index > 0 && |
|
rds_addr_cmp(&cp->cp_conn->c_laddr, &cp->cp_conn->c_faddr) >= 0) |
|
return; |
|
clear_bit(RDS_RECONNECT_PENDING, &cp->cp_flags); |
|
ret = rds_conn_path_transition(cp, RDS_CONN_DOWN, RDS_CONN_CONNECTING); |
|
if (ret) { |
|
ret = conn->c_trans->conn_path_connect(cp); |
|
rdsdebug("conn %p for %pI6c to %pI6c dispatched, ret %d\n", |
|
conn, &conn->c_laddr, &conn->c_faddr, ret); |
|
|
|
if (ret) { |
|
if (rds_conn_path_transition(cp, |
|
RDS_CONN_CONNECTING, |
|
RDS_CONN_DOWN)) |
|
rds_queue_reconnect(cp); |
|
else |
|
rds_conn_path_error(cp, "connect failed\n"); |
|
} |
|
} |
|
} |
|
|
|
void rds_send_worker(struct work_struct *work) |
|
{ |
|
struct rds_conn_path *cp = container_of(work, |
|
struct rds_conn_path, |
|
cp_send_w.work); |
|
int ret; |
|
|
|
if (rds_conn_path_state(cp) == RDS_CONN_UP) { |
|
clear_bit(RDS_LL_SEND_FULL, &cp->cp_flags); |
|
ret = rds_send_xmit(cp); |
|
cond_resched(); |
|
rdsdebug("conn %p ret %d\n", cp->cp_conn, ret); |
|
switch (ret) { |
|
case -EAGAIN: |
|
rds_stats_inc(s_send_immediate_retry); |
|
queue_delayed_work(rds_wq, &cp->cp_send_w, 0); |
|
break; |
|
case -ENOMEM: |
|
rds_stats_inc(s_send_delayed_retry); |
|
queue_delayed_work(rds_wq, &cp->cp_send_w, 2); |
|
break; |
|
default: |
|
break; |
|
} |
|
} |
|
} |
|
|
|
void rds_recv_worker(struct work_struct *work) |
|
{ |
|
struct rds_conn_path *cp = container_of(work, |
|
struct rds_conn_path, |
|
cp_recv_w.work); |
|
int ret; |
|
|
|
if (rds_conn_path_state(cp) == RDS_CONN_UP) { |
|
ret = cp->cp_conn->c_trans->recv_path(cp); |
|
rdsdebug("conn %p ret %d\n", cp->cp_conn, ret); |
|
switch (ret) { |
|
case -EAGAIN: |
|
rds_stats_inc(s_recv_immediate_retry); |
|
queue_delayed_work(rds_wq, &cp->cp_recv_w, 0); |
|
break; |
|
case -ENOMEM: |
|
rds_stats_inc(s_recv_delayed_retry); |
|
queue_delayed_work(rds_wq, &cp->cp_recv_w, 2); |
|
break; |
|
default: |
|
break; |
|
} |
|
} |
|
} |
|
|
|
void rds_shutdown_worker(struct work_struct *work) |
|
{ |
|
struct rds_conn_path *cp = container_of(work, |
|
struct rds_conn_path, |
|
cp_down_w); |
|
|
|
rds_conn_shutdown(cp); |
|
} |
|
|
|
void rds_threads_exit(void) |
|
{ |
|
destroy_workqueue(rds_wq); |
|
} |
|
|
|
int rds_threads_init(void) |
|
{ |
|
rds_wq = create_singlethread_workqueue("krdsd"); |
|
if (!rds_wq) |
|
return -ENOMEM; |
|
|
|
return 0; |
|
} |
|
|
|
/* Compare two IPv6 addresses. Return 0 if the two addresses are equal. |
|
* Return 1 if the first is greater. Return -1 if the second is greater. |
|
*/ |
|
int rds_addr_cmp(const struct in6_addr *addr1, |
|
const struct in6_addr *addr2) |
|
{ |
|
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 |
|
const __be64 *a1, *a2; |
|
u64 x, y; |
|
|
|
a1 = (__be64 *)addr1; |
|
a2 = (__be64 *)addr2; |
|
|
|
if (*a1 != *a2) { |
|
if (be64_to_cpu(*a1) < be64_to_cpu(*a2)) |
|
return -1; |
|
else |
|
return 1; |
|
} else { |
|
x = be64_to_cpu(*++a1); |
|
y = be64_to_cpu(*++a2); |
|
if (x < y) |
|
return -1; |
|
else if (x > y) |
|
return 1; |
|
else |
|
return 0; |
|
} |
|
#else |
|
u32 a, b; |
|
int i; |
|
|
|
for (i = 0; i < 4; i++) { |
|
if (addr1->s6_addr32[i] != addr2->s6_addr32[i]) { |
|
a = ntohl(addr1->s6_addr32[i]); |
|
b = ntohl(addr2->s6_addr32[i]); |
|
if (a < b) |
|
return -1; |
|
else if (a > b) |
|
return 1; |
|
} |
|
} |
|
return 0; |
|
#endif |
|
} |
|
EXPORT_SYMBOL_GPL(rds_addr_cmp);
|
|
|