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linux/fs/dlm/lowcomms.c
Alexander Aring b97f85259f fs: dlm: implement delayed ack handling 
This patch changes that we don't ack each message. Lowcomms will take
care about to send an ack back after a bulk of messages was processed.
Currently it's only when the whole receive buffer was processed, there
might better positions to send an ack back but only the lowcomms
implementation know when there are more data to receive. This patch has
also disadvantages that we might retransmit more on errors, however this
is a very rare case.

Tested with make_panic on gfs2 with three nodes by running:

trace-cmd record -p function -l 'dlm_send_ack' sleep 100

and

trace-cmd report | wc -l

Before patch:
- 20548
- 21376
- 21398

After patch:
- 18338
- 20679
- 19949

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
2021-08-19 11:33:03 -05:00

2020 lines
48 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-only
/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
**
**
*******************************************************************************
******************************************************************************/
/*
* lowcomms.c
*
* This is the "low-level" comms layer.
*
* It is responsible for sending/receiving messages
* from other nodes in the cluster.
*
* Cluster nodes are referred to by their nodeids. nodeids are
* simply 32 bit numbers to the locking module - if they need to
* be expanded for the cluster infrastructure then that is its
* responsibility. It is this layer's
* responsibility to resolve these into IP address or
* whatever it needs for inter-node communication.
*
* The comms level is two kernel threads that deal mainly with
* the receiving of messages from other nodes and passing them
* up to the mid-level comms layer (which understands the
* message format) for execution by the locking core, and
* a send thread which does all the setting up of connections
* to remote nodes and the sending of data. Threads are not allowed
* to send their own data because it may cause them to wait in times
* of high load. Also, this way, the sending thread can collect together
* messages bound for one node and send them in one block.
*
* lowcomms will choose to use either TCP or SCTP as its transport layer
* depending on the configuration variable 'protocol'. This should be set
* to 0 (default) for TCP or 1 for SCTP. It should be configured using a
* cluster-wide mechanism as it must be the same on all nodes of the cluster
* for the DLM to function.
*
*/
#include <asm/ioctls.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/mutex.h>
#include <linux/sctp.h>
#include <linux/slab.h>
#include <net/sctp/sctp.h>
#include <net/ipv6.h>
#include "dlm_internal.h"
#include "lowcomms.h"
#include "midcomms.h"
#include "config.h"
#define NEEDED_RMEM (4*1024*1024)
/* Number of messages to send before rescheduling */
#define MAX_SEND_MSG_COUNT 25
#define DLM_SHUTDOWN_WAIT_TIMEOUT msecs_to_jiffies(10000)
struct connection {
struct socket *sock; /* NULL if not connected */
uint32_t nodeid; /* So we know who we are in the list */
struct mutex sock_mutex;
unsigned long flags;
#define CF_READ_PENDING 1
#define CF_WRITE_PENDING 2
#define CF_INIT_PENDING 4
#define CF_IS_OTHERCON 5
#define CF_CLOSE 6
#define CF_APP_LIMITED 7
#define CF_CLOSING 8
#define CF_SHUTDOWN 9
#define CF_CONNECTED 10
#define CF_RECONNECT 11
#define CF_DELAY_CONNECT 12
#define CF_EOF 13
struct list_head writequeue; /* List of outgoing writequeue_entries */
spinlock_t writequeue_lock;
atomic_t writequeue_cnt;
struct mutex wq_alloc;
int retries;
#define MAX_CONNECT_RETRIES 3
struct hlist_node list;
struct connection *othercon;
struct connection *sendcon;
struct work_struct rwork; /* Receive workqueue */
struct work_struct swork; /* Send workqueue */
wait_queue_head_t shutdown_wait; /* wait for graceful shutdown */
unsigned char *rx_buf;
int rx_buflen;
int rx_leftover;
struct rcu_head rcu;
};
#define sock2con(x) ((struct connection *)(x)->sk_user_data)
struct listen_connection {
struct socket *sock;
struct work_struct rwork;
};
#define DLM_WQ_REMAIN_BYTES(e) (PAGE_SIZE - e->end)
#define DLM_WQ_LENGTH_BYTES(e) (e->end - e->offset)
/* An entry waiting to be sent */
struct writequeue_entry {
struct list_head list;
struct page *page;
int offset;
int len;
int end;
int users;
bool dirty;
struct connection *con;
struct list_head msgs;
struct kref ref;
};
struct dlm_msg {
struct writequeue_entry *entry;
struct dlm_msg *orig_msg;
bool retransmit;
void *ppc;
int len;
int idx; /* new()/commit() idx exchange */
struct list_head list;
struct kref ref;
};
struct dlm_node_addr {
struct list_head list;
int nodeid;
int mark;
int addr_count;
int curr_addr_index;
struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
};
struct dlm_proto_ops {
bool try_new_addr;
const char *name;
int proto;
int (*connect)(struct connection *con, struct socket *sock,
struct sockaddr *addr, int addr_len);
void (*sockopts)(struct socket *sock);
int (*bind)(struct socket *sock);
int (*listen_validate)(void);
void (*listen_sockopts)(struct socket *sock);
int (*listen_bind)(struct socket *sock);
/* What to do to shutdown */
void (*shutdown_action)(struct connection *con);
/* What to do to eof check */
bool (*eof_condition)(struct connection *con);
};
static struct listen_sock_callbacks {
void (*sk_error_report)(struct sock *);
void (*sk_data_ready)(struct sock *);
void (*sk_state_change)(struct sock *);
void (*sk_write_space)(struct sock *);
} listen_sock;
static LIST_HEAD(dlm_node_addrs);
static DEFINE_SPINLOCK(dlm_node_addrs_spin);
static struct listen_connection listen_con;
static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
static int dlm_local_count;
int dlm_allow_conn;
/* Work queues */
static struct workqueue_struct *recv_workqueue;
static struct workqueue_struct *send_workqueue;
static struct hlist_head connection_hash[CONN_HASH_SIZE];
static DEFINE_SPINLOCK(connections_lock);
DEFINE_STATIC_SRCU(connections_srcu);
static const struct dlm_proto_ops *dlm_proto_ops;
static void process_recv_sockets(struct work_struct *work);
static void process_send_sockets(struct work_struct *work);
/* need to held writequeue_lock */
static struct writequeue_entry *con_next_wq(struct connection *con)
{
struct writequeue_entry *e;
if (list_empty(&con->writequeue))
return NULL;
e = list_first_entry(&con->writequeue, struct writequeue_entry,
list);
if (e->len == 0)
return NULL;
return e;
}
static struct connection *__find_con(int nodeid, int r)
{
struct connection *con;
hlist_for_each_entry_rcu(con, &connection_hash[r], list) {
if (con->nodeid == nodeid)
return con;
}
return NULL;
}
static bool tcp_eof_condition(struct connection *con)
{
return atomic_read(&con->writequeue_cnt);
}
static int dlm_con_init(struct connection *con, int nodeid)
{
con->rx_buflen = dlm_config.ci_buffer_size;
con->rx_buf = kmalloc(con->rx_buflen, GFP_NOFS);
if (!con->rx_buf)
return -ENOMEM;
con->nodeid = nodeid;
mutex_init(&con->sock_mutex);
INIT_LIST_HEAD(&con->writequeue);
spin_lock_init(&con->writequeue_lock);
atomic_set(&con->writequeue_cnt, 0);
INIT_WORK(&con->swork, process_send_sockets);
INIT_WORK(&con->rwork, process_recv_sockets);
init_waitqueue_head(&con->shutdown_wait);
return 0;
}
/*
* If 'allocation' is zero then we don't attempt to create a new
* connection structure for this node.
*/
static struct connection *nodeid2con(int nodeid, gfp_t alloc)
{
struct connection *con, *tmp;
int r, ret;
r = nodeid_hash(nodeid);
con = __find_con(nodeid, r);
if (con || !alloc)
return con;
con = kzalloc(sizeof(*con), alloc);
if (!con)
return NULL;
ret = dlm_con_init(con, nodeid);
if (ret) {
kfree(con);
return NULL;
}
mutex_init(&con->wq_alloc);
spin_lock(&connections_lock);
/* Because multiple workqueues/threads calls this function it can
* race on multiple cpu's. Instead of locking hot path __find_con()
* we just check in rare cases of recently added nodes again
* under protection of connections_lock. If this is the case we
* abort our connection creation and return the existing connection.
*/
tmp = __find_con(nodeid, r);
if (tmp) {
spin_unlock(&connections_lock);
kfree(con->rx_buf);
kfree(con);
return tmp;
}
hlist_add_head_rcu(&con->list, &connection_hash[r]);
spin_unlock(&connections_lock);
return con;
}
/* Loop round all connections */
static void foreach_conn(void (*conn_func)(struct connection *c))
{
int i;
struct connection *con;
for (i = 0; i < CONN_HASH_SIZE; i++) {
hlist_for_each_entry_rcu(con, &connection_hash[i], list)
conn_func(con);
}
}
static struct dlm_node_addr *find_node_addr(int nodeid)
{
struct dlm_node_addr *na;
list_for_each_entry(na, &dlm_node_addrs, list) {
if (na->nodeid == nodeid)
return na;
}
return NULL;
}
static int addr_compare(const struct sockaddr_storage *x,
const struct sockaddr_storage *y)
{
switch (x->ss_family) {
case AF_INET: {
struct sockaddr_in *sinx = (struct sockaddr_in *)x;
struct sockaddr_in *siny = (struct sockaddr_in *)y;
if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr)
return 0;
if (sinx->sin_port != siny->sin_port)
return 0;
break;
}
case AF_INET6: {
struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x;
struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y;
if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr))
return 0;
if (sinx->sin6_port != siny->sin6_port)
return 0;
break;
}
default:
return 0;
}
return 1;
}
static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out,
struct sockaddr *sa_out, bool try_new_addr,
unsigned int *mark)
{
struct sockaddr_storage sas;
struct dlm_node_addr *na;
if (!dlm_local_count)
return -1;
spin_lock(&dlm_node_addrs_spin);
na = find_node_addr(nodeid);
if (na && na->addr_count) {
memcpy(&sas, na->addr[na->curr_addr_index],
sizeof(struct sockaddr_storage));
if (try_new_addr) {
na->curr_addr_index++;
if (na->curr_addr_index == na->addr_count)
na->curr_addr_index = 0;
}
}
spin_unlock(&dlm_node_addrs_spin);
if (!na)
return -EEXIST;
if (!na->addr_count)
return -ENOENT;
*mark = na->mark;
if (sas_out)
memcpy(sas_out, &sas, sizeof(struct sockaddr_storage));
if (!sa_out)
return 0;
if (dlm_local_addr[0]->ss_family == AF_INET) {
struct sockaddr_in *in4 = (struct sockaddr_in *) &sas;
struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out;
ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
} else {
struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas;
struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out;
ret6->sin6_addr = in6->sin6_addr;
}
return 0;
}
static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid,
unsigned int *mark)
{
struct dlm_node_addr *na;
int rv = -EEXIST;
int addr_i;
spin_lock(&dlm_node_addrs_spin);
list_for_each_entry(na, &dlm_node_addrs, list) {
if (!na->addr_count)
continue;
for (addr_i = 0; addr_i < na->addr_count; addr_i++) {
if (addr_compare(na->addr[addr_i], addr)) {
*nodeid = na->nodeid;
*mark = na->mark;
rv = 0;
goto unlock;
}
}
}
unlock:
spin_unlock(&dlm_node_addrs_spin);
return rv;
}
/* caller need to held dlm_node_addrs_spin lock */
static bool dlm_lowcomms_na_has_addr(const struct dlm_node_addr *na,
const struct sockaddr_storage *addr)
{
int i;
for (i = 0; i < na->addr_count; i++) {
if (addr_compare(na->addr[i], addr))
return true;
}
return false;
}
int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len)
{
struct sockaddr_storage *new_addr;
struct dlm_node_addr *new_node, *na;
bool ret;
new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS);
if (!new_node)
return -ENOMEM;
new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS);
if (!new_addr) {
kfree(new_node);
return -ENOMEM;
}
memcpy(new_addr, addr, len);
spin_lock(&dlm_node_addrs_spin);
na = find_node_addr(nodeid);
if (!na) {
new_node->nodeid = nodeid;
new_node->addr[0] = new_addr;
new_node->addr_count = 1;
new_node->mark = dlm_config.ci_mark;
list_add(&new_node->list, &dlm_node_addrs);
spin_unlock(&dlm_node_addrs_spin);
return 0;
}
ret = dlm_lowcomms_na_has_addr(na, addr);
if (ret) {
spin_unlock(&dlm_node_addrs_spin);
kfree(new_addr);
kfree(new_node);
return -EEXIST;
}
if (na->addr_count >= DLM_MAX_ADDR_COUNT) {
spin_unlock(&dlm_node_addrs_spin);
kfree(new_addr);
kfree(new_node);
return -ENOSPC;
}
na->addr[na->addr_count++] = new_addr;
spin_unlock(&dlm_node_addrs_spin);
kfree(new_node);
return 0;
}
/* Data available on socket or listen socket received a connect */
static void lowcomms_data_ready(struct sock *sk)
{
struct connection *con;
read_lock_bh(&sk->sk_callback_lock);
con = sock2con(sk);
if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags))
queue_work(recv_workqueue, &con->rwork);
read_unlock_bh(&sk->sk_callback_lock);
}
static void lowcomms_listen_data_ready(struct sock *sk)
{
if (!dlm_allow_conn)
return;
queue_work(recv_workqueue, &listen_con.rwork);
}
static void lowcomms_write_space(struct sock *sk)
{
struct connection *con;
read_lock_bh(&sk->sk_callback_lock);
con = sock2con(sk);
if (!con)
goto out;
if (!test_and_set_bit(CF_CONNECTED, &con->flags)) {
log_print("successful connected to node %d", con->nodeid);
queue_work(send_workqueue, &con->swork);
goto out;
}
clear_bit(SOCK_NOSPACE, &con->sock->flags);
if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) {
con->sock->sk->sk_write_pending--;
clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags);
}
queue_work(send_workqueue, &con->swork);
out:
read_unlock_bh(&sk->sk_callback_lock);
}
static inline void lowcomms_connect_sock(struct connection *con)
{
if (test_bit(CF_CLOSE, &con->flags))
return;
queue_work(send_workqueue, &con->swork);
cond_resched();
}
static void lowcomms_state_change(struct sock *sk)
{
/* SCTP layer is not calling sk_data_ready when the connection
* is done, so we catch the signal through here. Also, it
* doesn't switch socket state when entering shutdown, so we
* skip the write in that case.
*/
if (sk->sk_shutdown) {
if (sk->sk_shutdown == RCV_SHUTDOWN)
lowcomms_data_ready(sk);
} else if (sk->sk_state == TCP_ESTABLISHED) {
lowcomms_write_space(sk);
}
}
int dlm_lowcomms_connect_node(int nodeid)
{
struct connection *con;
int idx;
if (nodeid == dlm_our_nodeid())
return 0;
idx = srcu_read_lock(&connections_srcu);
con = nodeid2con(nodeid, GFP_NOFS);
if (!con) {
srcu_read_unlock(&connections_srcu, idx);
return -ENOMEM;
}
lowcomms_connect_sock(con);
srcu_read_unlock(&connections_srcu, idx);
return 0;
}
int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark)
{
struct dlm_node_addr *na;
spin_lock(&dlm_node_addrs_spin);
na = find_node_addr(nodeid);
if (!na) {
spin_unlock(&dlm_node_addrs_spin);
return -ENOENT;
}
na->mark = mark;
spin_unlock(&dlm_node_addrs_spin);
return 0;
}
static void lowcomms_error_report(struct sock *sk)
{
struct connection *con;
struct sockaddr_storage saddr;
void (*orig_report)(struct sock *) = NULL;
read_lock_bh(&sk->sk_callback_lock);
con = sock2con(sk);
if (con == NULL)
goto out;
orig_report = listen_sock.sk_error_report;
if (kernel_getpeername(sk->sk_socket, (struct sockaddr *)&saddr) < 0) {
printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
"sending to node %d, port %d, "
"sk_err=%d/%d\n", dlm_our_nodeid(),
con->nodeid, dlm_config.ci_tcp_port,
sk->sk_err, sk->sk_err_soft);
} else if (saddr.ss_family == AF_INET) {
struct sockaddr_in *sin4 = (struct sockaddr_in *)&saddr;
printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
"sending to node %d at %pI4, port %d, "
"sk_err=%d/%d\n", dlm_our_nodeid(),
con->nodeid, &sin4->sin_addr.s_addr,
dlm_config.ci_tcp_port, sk->sk_err,
sk->sk_err_soft);
} else {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&saddr;
printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
"sending to node %d at %u.%u.%u.%u, "
"port %d, sk_err=%d/%d\n", dlm_our_nodeid(),
con->nodeid, sin6->sin6_addr.s6_addr32[0],
sin6->sin6_addr.s6_addr32[1],
sin6->sin6_addr.s6_addr32[2],
sin6->sin6_addr.s6_addr32[3],
dlm_config.ci_tcp_port, sk->sk_err,
sk->sk_err_soft);
}
/* below sendcon only handling */
if (test_bit(CF_IS_OTHERCON, &con->flags))
con = con->sendcon;
switch (sk->sk_err) {
case ECONNREFUSED:
set_bit(CF_DELAY_CONNECT, &con->flags);
break;
default:
break;
}
if (!test_and_set_bit(CF_RECONNECT, &con->flags))
queue_work(send_workqueue, &con->swork);
out:
read_unlock_bh(&sk->sk_callback_lock);
if (orig_report)
orig_report(sk);
}
/* Note: sk_callback_lock must be locked before calling this function. */
static void save_listen_callbacks(struct socket *sock)
{
struct sock *sk = sock->sk;
listen_sock.sk_data_ready = sk->sk_data_ready;
listen_sock.sk_state_change = sk->sk_state_change;
listen_sock.sk_write_space = sk->sk_write_space;
listen_sock.sk_error_report = sk->sk_error_report;
}
static void restore_callbacks(struct socket *sock)
{
struct sock *sk = sock->sk;
write_lock_bh(&sk->sk_callback_lock);
sk->sk_user_data = NULL;
sk->sk_data_ready = listen_sock.sk_data_ready;
sk->sk_state_change = listen_sock.sk_state_change;
sk->sk_write_space = listen_sock.sk_write_space;
sk->sk_error_report = listen_sock.sk_error_report;
write_unlock_bh(&sk->sk_callback_lock);
}
static void add_listen_sock(struct socket *sock, struct listen_connection *con)
{
struct sock *sk = sock->sk;
write_lock_bh(&sk->sk_callback_lock);
save_listen_callbacks(sock);
con->sock = sock;
sk->sk_user_data = con;
sk->sk_allocation = GFP_NOFS;
/* Install a data_ready callback */
sk->sk_data_ready = lowcomms_listen_data_ready;
write_unlock_bh(&sk->sk_callback_lock);
}
/* Make a socket active */
static void add_sock(struct socket *sock, struct connection *con)
{
struct sock *sk = sock->sk;
write_lock_bh(&sk->sk_callback_lock);
con->sock = sock;
sk->sk_user_data = con;
/* Install a data_ready callback */
sk->sk_data_ready = lowcomms_data_ready;
sk->sk_write_space = lowcomms_write_space;
sk->sk_state_change = lowcomms_state_change;
sk->sk_allocation = GFP_NOFS;
sk->sk_error_report = lowcomms_error_report;
write_unlock_bh(&sk->sk_callback_lock);
}
/* Add the port number to an IPv6 or 4 sockaddr and return the address
length */
static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
int *addr_len)
{
saddr->ss_family = dlm_local_addr[0]->ss_family;
if (saddr->ss_family == AF_INET) {
struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
in4_addr->sin_port = cpu_to_be16(port);
*addr_len = sizeof(struct sockaddr_in);
memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
} else {
struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
in6_addr->sin6_port = cpu_to_be16(port);
*addr_len = sizeof(struct sockaddr_in6);
}
memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
}
static void dlm_page_release(struct kref *kref)
{
struct writequeue_entry *e = container_of(kref, struct writequeue_entry,
ref);
__free_page(e->page);
kfree(e);
}
static void dlm_msg_release(struct kref *kref)
{
struct dlm_msg *msg = container_of(kref, struct dlm_msg, ref);
kref_put(&msg->entry->ref, dlm_page_release);
kfree(msg);
}
static void free_entry(struct writequeue_entry *e)
{
struct dlm_msg *msg, *tmp;
list_for_each_entry_safe(msg, tmp, &e->msgs, list) {
if (msg->orig_msg) {
msg->orig_msg->retransmit = false;
kref_put(&msg->orig_msg->ref, dlm_msg_release);
}
list_del(&msg->list);
kref_put(&msg->ref, dlm_msg_release);
}
list_del(&e->list);
atomic_dec(&e->con->writequeue_cnt);
kref_put(&e->ref, dlm_page_release);
}
static void dlm_close_sock(struct socket **sock)
{
if (*sock) {
restore_callbacks(*sock);
sock_release(*sock);
*sock = NULL;
}
}
/* Close a remote connection and tidy up */
static void close_connection(struct connection *con, bool and_other,
bool tx, bool rx)
{
bool closing = test_and_set_bit(CF_CLOSING, &con->flags);
struct writequeue_entry *e;
if (tx && !closing && cancel_work_sync(&con->swork)) {
log_print("canceled swork for node %d", con->nodeid);
clear_bit(CF_WRITE_PENDING, &con->flags);
}
if (rx && !closing && cancel_work_sync(&con->rwork)) {
log_print("canceled rwork for node %d", con->nodeid);
clear_bit(CF_READ_PENDING, &con->flags);
}
mutex_lock(&con->sock_mutex);
dlm_close_sock(&con->sock);
if (con->othercon && and_other) {
/* Will only re-enter once. */
close_connection(con->othercon, false, tx, rx);
}
/* if we send a writequeue entry only a half way, we drop the
* whole entry because reconnection and that we not start of the
* middle of a msg which will confuse the other end.
*
* we can always drop messages because retransmits, but what we
* cannot allow is to transmit half messages which may be processed
* at the other side.
*
* our policy is to start on a clean state when disconnects, we don't
* know what's send/received on transport layer in this case.
*/
spin_lock(&con->writequeue_lock);
if (!list_empty(&con->writequeue)) {
e = list_first_entry(&con->writequeue, struct writequeue_entry,
list);
if (e->dirty)
free_entry(e);
}
spin_unlock(&con->writequeue_lock);
con->rx_leftover = 0;
con->retries = 0;
clear_bit(CF_APP_LIMITED, &con->flags);
clear_bit(CF_CONNECTED, &con->flags);
clear_bit(CF_DELAY_CONNECT, &con->flags);
clear_bit(CF_RECONNECT, &con->flags);
clear_bit(CF_EOF, &con->flags);
mutex_unlock(&con->sock_mutex);
clear_bit(CF_CLOSING, &con->flags);
}
static void shutdown_connection(struct connection *con)
{
int ret;
flush_work(&con->swork);
mutex_lock(&con->sock_mutex);
/* nothing to shutdown */
if (!con->sock) {
mutex_unlock(&con->sock_mutex);
return;
}
set_bit(CF_SHUTDOWN, &con->flags);
ret = kernel_sock_shutdown(con->sock, SHUT_WR);
mutex_unlock(&con->sock_mutex);
if (ret) {
log_print("Connection %p failed to shutdown: %d will force close",
con, ret);
goto force_close;
} else {
ret = wait_event_timeout(con->shutdown_wait,
!test_bit(CF_SHUTDOWN, &con->flags),
DLM_SHUTDOWN_WAIT_TIMEOUT);
if (ret == 0) {
log_print("Connection %p shutdown timed out, will force close",
con);
goto force_close;
}
}
return;
force_close:
clear_bit(CF_SHUTDOWN, &con->flags);
close_connection(con, false, true, true);
}
static void dlm_tcp_shutdown(struct connection *con)
{
if (con->othercon)
shutdown_connection(con->othercon);
shutdown_connection(con);
}
static int con_realloc_receive_buf(struct connection *con, int newlen)
{
unsigned char *newbuf;
newbuf = kmalloc(newlen, GFP_NOFS);
if (!newbuf)
return -ENOMEM;
/* copy any leftover from last receive */
if (con->rx_leftover)
memmove(newbuf, con->rx_buf, con->rx_leftover);
/* swap to new buffer space */
kfree(con->rx_buf);
con->rx_buflen = newlen;
con->rx_buf = newbuf;
return 0;
}
/* Data received from remote end */
static int receive_from_sock(struct connection *con)
{
struct msghdr msg;
struct kvec iov;
int ret, buflen;
mutex_lock(&con->sock_mutex);
if (con->sock == NULL) {
ret = -EAGAIN;
goto out_close;
}
/* realloc if we get new buffer size to read out */
buflen = dlm_config.ci_buffer_size;
if (con->rx_buflen != buflen && con->rx_leftover <= buflen) {
ret = con_realloc_receive_buf(con, buflen);
if (ret < 0)
goto out_resched;
}
for (;;) {
/* calculate new buffer parameter regarding last receive and
* possible leftover bytes
*/
iov.iov_base = con->rx_buf + con->rx_leftover;
iov.iov_len = con->rx_buflen - con->rx_leftover;
memset(&msg, 0, sizeof(msg));
msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len,
msg.msg_flags);
if (ret == -EAGAIN)
break;
else if (ret <= 0)
goto out_close;
/* new buflen according readed bytes and leftover from last receive */
buflen = ret + con->rx_leftover;
ret = dlm_process_incoming_buffer(con->nodeid, con->rx_buf, buflen);
if (ret < 0)
goto out_close;
/* calculate leftover bytes from process and put it into begin of
* the receive buffer, so next receive we have the full message
* at the start address of the receive buffer.
*/
con->rx_leftover = buflen - ret;
if (con->rx_leftover) {
memmove(con->rx_buf, con->rx_buf + ret,
con->rx_leftover);
}
}
dlm_midcomms_receive_done(con->nodeid);
mutex_unlock(&con->sock_mutex);
return 0;
out_resched:
if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
queue_work(recv_workqueue, &con->rwork);
mutex_unlock(&con->sock_mutex);
return -EAGAIN;
out_close:
if (ret == 0) {
log_print("connection %p got EOF from %d",
con, con->nodeid);
if (dlm_proto_ops->eof_condition &&
dlm_proto_ops->eof_condition(con)) {
set_bit(CF_EOF, &con->flags);
mutex_unlock(&con->sock_mutex);
} else {
mutex_unlock(&con->sock_mutex);
close_connection(con, false, true, false);
/* handling for tcp shutdown */
clear_bit(CF_SHUTDOWN, &con->flags);
wake_up(&con->shutdown_wait);
}
/* signal to breaking receive worker */
ret = -1;
} else {
mutex_unlock(&con->sock_mutex);
}
return ret;
}
/* Listening socket is busy, accept a connection */
static int accept_from_sock(struct listen_connection *con)
{
int result;
struct sockaddr_storage peeraddr;
struct socket *newsock;
int len, idx;
int nodeid;
struct connection *newcon;
struct connection *addcon;
unsigned int mark;
if (!con->sock)
return -ENOTCONN;
result = kernel_accept(con->sock, &newsock, O_NONBLOCK);
if (result < 0)
goto accept_err;
/* Get the connected socket's peer */
memset(&peeraddr, 0, sizeof(peeraddr));
len = newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 2);
if (len < 0) {
result = -ECONNABORTED;
goto accept_err;
}
/* Get the new node's NODEID */
make_sockaddr(&peeraddr, 0, &len);
if (addr_to_nodeid(&peeraddr, &nodeid, &mark)) {
unsigned char *b=(unsigned char *)&peeraddr;
log_print("connect from non cluster node");
print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE,
b, sizeof(struct sockaddr_storage));
sock_release(newsock);
return -1;
}
log_print("got connection from %d", nodeid);
/* Check to see if we already have a connection to this node. This
* could happen if the two nodes initiate a connection at roughly
* the same time and the connections cross on the wire.
* In this case we store the incoming one in "othercon"
*/
idx = srcu_read_lock(&connections_srcu);
newcon = nodeid2con(nodeid, GFP_NOFS);
if (!newcon) {
srcu_read_unlock(&connections_srcu, idx);
result = -ENOMEM;
goto accept_err;
}
sock_set_mark(newsock->sk, mark);
mutex_lock(&newcon->sock_mutex);
if (newcon->sock) {
struct connection *othercon = newcon->othercon;
if (!othercon) {
othercon = kzalloc(sizeof(*othercon), GFP_NOFS);
if (!othercon) {
log_print("failed to allocate incoming socket");
mutex_unlock(&newcon->sock_mutex);
srcu_read_unlock(&connections_srcu, idx);
result = -ENOMEM;
goto accept_err;
}
result = dlm_con_init(othercon, nodeid);
if (result < 0) {
kfree(othercon);
mutex_unlock(&newcon->sock_mutex);
srcu_read_unlock(&connections_srcu, idx);
goto accept_err;
}
lockdep_set_subclass(&othercon->sock_mutex, 1);
set_bit(CF_IS_OTHERCON, &othercon->flags);
newcon->othercon = othercon;
othercon->sendcon = newcon;
} else {
/* close other sock con if we have something new */
close_connection(othercon, false, true, false);
}
mutex_lock(&othercon->sock_mutex);
add_sock(newsock, othercon);
addcon = othercon;
mutex_unlock(&othercon->sock_mutex);
}
else {
/* accept copies the sk after we've saved the callbacks, so we
don't want to save them a second time or comm errors will
result in calling sk_error_report recursively. */
add_sock(newsock, newcon);
addcon = newcon;
}
set_bit(CF_CONNECTED, &addcon->flags);
mutex_unlock(&newcon->sock_mutex);
/*
* Add it to the active queue in case we got data
* between processing the accept adding the socket
* to the read_sockets list
*/
if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
queue_work(recv_workqueue, &addcon->rwork);
srcu_read_unlock(&connections_srcu, idx);
return 0;
accept_err:
if (newsock)
sock_release(newsock);
if (result != -EAGAIN)
log_print("error accepting connection from node: %d", result);
return result;
}
/*
* writequeue_entry_complete - try to delete and free write queue entry
* @e: write queue entry to try to delete
* @completed: bytes completed
*
* writequeue_lock must be held.
*/
static void writequeue_entry_complete(struct writequeue_entry *e, int completed)
{
e->offset += completed;
e->len -= completed;
/* signal that page was half way transmitted */
e->dirty = true;
if (e->len == 0 && e->users == 0)
free_entry(e);
}
/*
* sctp_bind_addrs - bind a SCTP socket to all our addresses
*/
static int sctp_bind_addrs(struct socket *sock, uint16_t port)
{
struct sockaddr_storage localaddr;
struct sockaddr *addr = (struct sockaddr *)&localaddr;
int i, addr_len, result = 0;
for (i = 0; i < dlm_local_count; i++) {
memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
make_sockaddr(&localaddr, port, &addr_len);
if (!i)
result = kernel_bind(sock, addr, addr_len);
else
result = sock_bind_add(sock->sk, addr, addr_len);
if (result < 0) {
log_print("Can't bind to %d addr number %d, %d.\n",
port, i + 1, result);
break;
}
}
return result;
}
/* Get local addresses */
static void init_local(void)
{
struct sockaddr_storage sas, *addr;
int i;
dlm_local_count = 0;
for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) {
if (dlm_our_addr(&sas, i))
break;
addr = kmemdup(&sas, sizeof(*addr), GFP_NOFS);
if (!addr)
break;
dlm_local_addr[dlm_local_count++] = addr;
}
}
static void deinit_local(void)
{
int i;
for (i = 0; i < dlm_local_count; i++)
kfree(dlm_local_addr[i]);
}
static struct writequeue_entry *new_writequeue_entry(struct connection *con,
gfp_t allocation)
{
struct writequeue_entry *entry;
entry = kzalloc(sizeof(*entry), allocation);
if (!entry)
return NULL;
entry->page = alloc_page(allocation | __GFP_ZERO);
if (!entry->page) {
kfree(entry);
return NULL;
}
entry->con = con;
entry->users = 1;
kref_init(&entry->ref);
INIT_LIST_HEAD(&entry->msgs);
return entry;
}
static struct writequeue_entry *new_wq_entry(struct connection *con, int len,
gfp_t allocation, char **ppc,
void (*cb)(struct dlm_mhandle *mh),
struct dlm_mhandle *mh)
{
struct writequeue_entry *e;
spin_lock(&con->writequeue_lock);
if (!list_empty(&con->writequeue)) {
e = list_last_entry(&con->writequeue, struct writequeue_entry, list);
if (DLM_WQ_REMAIN_BYTES(e) >= len) {
kref_get(&e->ref);
*ppc = page_address(e->page) + e->end;
if (cb)
cb(mh);
e->end += len;
e->users++;
spin_unlock(&con->writequeue_lock);
return e;
}
}
spin_unlock(&con->writequeue_lock);
e = new_writequeue_entry(con, allocation);
if (!e)
return NULL;
kref_get(&e->ref);
*ppc = page_address(e->page);
e->end += len;
atomic_inc(&con->writequeue_cnt);
spin_lock(&con->writequeue_lock);
if (cb)
cb(mh);
list_add_tail(&e->list, &con->writequeue);
spin_unlock(&con->writequeue_lock);
return e;
};
static struct dlm_msg *dlm_lowcomms_new_msg_con(struct connection *con, int len,
gfp_t allocation, char **ppc,
void (*cb)(struct dlm_mhandle *mh),
struct dlm_mhandle *mh)
{
struct writequeue_entry *e;
struct dlm_msg *msg;
bool sleepable;
msg = kzalloc(sizeof(*msg), allocation);
if (!msg)
return NULL;
/* this mutex is being used as a wait to avoid multiple "fast"
* new writequeue page list entry allocs in new_wq_entry in
* normal operation which is sleepable context. Without it
* we could end in multiple writequeue entries with one
* dlm message because multiple callers were waiting at
* the writequeue_lock in new_wq_entry().
*/
sleepable = gfpflags_normal_context(allocation);
if (sleepable)
mutex_lock(&con->wq_alloc);
kref_init(&msg->ref);
e = new_wq_entry(con, len, allocation, ppc, cb, mh);
if (!e) {
if (sleepable)
mutex_unlock(&con->wq_alloc);
kfree(msg);
return NULL;
}
if (sleepable)
mutex_unlock(&con->wq_alloc);
msg->ppc = *ppc;
msg->len = len;
msg->entry = e;
return msg;
}
struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation,
char **ppc, void (*cb)(struct dlm_mhandle *mh),
struct dlm_mhandle *mh)
{
struct connection *con;
struct dlm_msg *msg;
int idx;
if (len > DLM_MAX_SOCKET_BUFSIZE ||
len < sizeof(struct dlm_header)) {
BUILD_BUG_ON(PAGE_SIZE < DLM_MAX_SOCKET_BUFSIZE);
log_print("failed to allocate a buffer of size %d", len);
WARN_ON(1);
return NULL;
}
idx = srcu_read_lock(&connections_srcu);
con = nodeid2con(nodeid, allocation);
if (!con) {
srcu_read_unlock(&connections_srcu, idx);
return NULL;
}
msg = dlm_lowcomms_new_msg_con(con, len, allocation, ppc, cb, mh);
if (!msg) {
srcu_read_unlock(&connections_srcu, idx);
return NULL;
}
/* we assume if successful commit must called */
msg->idx = idx;
return msg;
}
static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg)
{
struct writequeue_entry *e = msg->entry;
struct connection *con = e->con;
int users;
spin_lock(&con->writequeue_lock);
kref_get(&msg->ref);
list_add(&msg->list, &e->msgs);
users = --e->users;
if (users)
goto out;
e->len = DLM_WQ_LENGTH_BYTES(e);
spin_unlock(&con->writequeue_lock);
queue_work(send_workqueue, &con->swork);
return;
out:
spin_unlock(&con->writequeue_lock);
return;
}
void dlm_lowcomms_commit_msg(struct dlm_msg *msg)
{
_dlm_lowcomms_commit_msg(msg);
srcu_read_unlock(&connections_srcu, msg->idx);
}
void dlm_lowcomms_put_msg(struct dlm_msg *msg)
{
kref_put(&msg->ref, dlm_msg_release);
}
/* does not held connections_srcu, usage workqueue only */
int dlm_lowcomms_resend_msg(struct dlm_msg *msg)
{
struct dlm_msg *msg_resend;
char *ppc;
if (msg->retransmit)
return 1;
msg_resend = dlm_lowcomms_new_msg_con(msg->entry->con, msg->len,
GFP_ATOMIC, &ppc, NULL, NULL);
if (!msg_resend)
return -ENOMEM;
msg->retransmit = true;
kref_get(&msg->ref);
msg_resend->orig_msg = msg;
memcpy(ppc, msg->ppc, msg->len);
_dlm_lowcomms_commit_msg(msg_resend);
dlm_lowcomms_put_msg(msg_resend);
return 0;
}
/* Send a message */
static void send_to_sock(struct connection *con)
{
const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
struct writequeue_entry *e;
int len, offset, ret;
int count = 0;
mutex_lock(&con->sock_mutex);
if (con->sock == NULL)
goto out_connect;
spin_lock(&con->writequeue_lock);
for (;;) {
e = con_next_wq(con);
if (!e)
break;
e = list_first_entry(&con->writequeue, struct writequeue_entry, list);
len = e->len;
offset = e->offset;
BUG_ON(len == 0 && e->users == 0);
spin_unlock(&con->writequeue_lock);
ret = kernel_sendpage(con->sock, e->page, offset, len,
msg_flags);
if (ret == -EAGAIN || ret == 0) {
if (ret == -EAGAIN &&
test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) &&
!test_and_set_bit(CF_APP_LIMITED, &con->flags)) {
/* Notify TCP that we're limited by the
* application window size.
*/
set_bit(SOCK_NOSPACE, &con->sock->flags);
con->sock->sk->sk_write_pending++;
}
cond_resched();
goto out;
} else if (ret < 0)
goto out;
/* Don't starve people filling buffers */
if (++count >= MAX_SEND_MSG_COUNT) {
cond_resched();
count = 0;
}
spin_lock(&con->writequeue_lock);
writequeue_entry_complete(e, ret);
}
spin_unlock(&con->writequeue_lock);
/* close if we got EOF */
if (test_and_clear_bit(CF_EOF, &con->flags)) {
mutex_unlock(&con->sock_mutex);
close_connection(con, false, false, true);
/* handling for tcp shutdown */
clear_bit(CF_SHUTDOWN, &con->flags);
wake_up(&con->shutdown_wait);
} else {
mutex_unlock(&con->sock_mutex);
}
return;
out:
mutex_unlock(&con->sock_mutex);
return;
out_connect:
mutex_unlock(&con->sock_mutex);
queue_work(send_workqueue, &con->swork);
cond_resched();
}
static void clean_one_writequeue(struct connection *con)
{
struct writequeue_entry *e, *safe;
spin_lock(&con->writequeue_lock);
list_for_each_entry_safe(e, safe, &con->writequeue, list) {
free_entry(e);
}
spin_unlock(&con->writequeue_lock);
}
/* Called from recovery when it knows that a node has
left the cluster */
int dlm_lowcomms_close(int nodeid)
{
struct connection *con;
struct dlm_node_addr *na;
int idx;
log_print("closing connection to node %d", nodeid);
idx = srcu_read_lock(&connections_srcu);
con = nodeid2con(nodeid, 0);
if (con) {
set_bit(CF_CLOSE, &con->flags);
close_connection(con, true, true, true);
clean_one_writequeue(con);
if (con->othercon)
clean_one_writequeue(con->othercon);
}
srcu_read_unlock(&connections_srcu, idx);
spin_lock(&dlm_node_addrs_spin);
na = find_node_addr(nodeid);
if (na) {
list_del(&na->list);
while (na->addr_count--)
kfree(na->addr[na->addr_count]);
kfree(na);
}
spin_unlock(&dlm_node_addrs_spin);
return 0;
}
/* Receive workqueue function */
static void process_recv_sockets(struct work_struct *work)
{
struct connection *con = container_of(work, struct connection, rwork);
clear_bit(CF_READ_PENDING, &con->flags);
receive_from_sock(con);
}
static void process_listen_recv_socket(struct work_struct *work)
{
accept_from_sock(&listen_con);
}
static void dlm_connect(struct connection *con)
{
struct sockaddr_storage addr;
int result, addr_len;
struct socket *sock;
unsigned int mark;
/* Some odd races can cause double-connects, ignore them */
if (con->retries++ > MAX_CONNECT_RETRIES)
return;
if (con->sock) {
log_print("node %d already connected.", con->nodeid);
return;
}
memset(&addr, 0, sizeof(addr));
result = nodeid_to_addr(con->nodeid, &addr, NULL,
dlm_proto_ops->try_new_addr, &mark);
if (result < 0) {
log_print("no address for nodeid %d", con->nodeid);
return;
}
/* Create a socket to communicate with */
result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
SOCK_STREAM, dlm_proto_ops->proto, &sock);
if (result < 0)
goto socket_err;
sock_set_mark(sock->sk, mark);
dlm_proto_ops->sockopts(sock);
add_sock(sock, con);
result = dlm_proto_ops->bind(sock);
if (result < 0)
goto add_sock_err;
log_print_ratelimited("connecting to %d", con->nodeid);
make_sockaddr(&addr, dlm_config.ci_tcp_port, &addr_len);
result = dlm_proto_ops->connect(con, sock, (struct sockaddr *)&addr,
addr_len);
if (result < 0)
goto add_sock_err;
return;
add_sock_err:
dlm_close_sock(&con->sock);
socket_err:
/*
* Some errors are fatal and this list might need adjusting. For other
* errors we try again until the max number of retries is reached.
*/
if (result != -EHOSTUNREACH &&
result != -ENETUNREACH &&
result != -ENETDOWN &&
result != -EINVAL &&
result != -EPROTONOSUPPORT) {
log_print("connect %d try %d error %d", con->nodeid,
con->retries, result);
msleep(1000);
lowcomms_connect_sock(con);
}
}
/* Send workqueue function */
static void process_send_sockets(struct work_struct *work)
{
struct connection *con = container_of(work, struct connection, swork);
WARN_ON(test_bit(CF_IS_OTHERCON, &con->flags));
clear_bit(CF_WRITE_PENDING, &con->flags);
if (test_and_clear_bit(CF_RECONNECT, &con->flags)) {
close_connection(con, false, false, true);
dlm_midcomms_unack_msg_resend(con->nodeid);
}
if (con->sock == NULL) {
if (test_and_clear_bit(CF_DELAY_CONNECT, &con->flags))
msleep(1000);
mutex_lock(&con->sock_mutex);
dlm_connect(con);
mutex_unlock(&con->sock_mutex);
}
if (!list_empty(&con->writequeue))
send_to_sock(con);
}
static void work_stop(void)
{
if (recv_workqueue) {
destroy_workqueue(recv_workqueue);
recv_workqueue = NULL;
}
if (send_workqueue) {
destroy_workqueue(send_workqueue);
send_workqueue = NULL;
}
}
static int work_start(void)
{
recv_workqueue = alloc_ordered_workqueue("dlm_recv", WQ_MEM_RECLAIM);
if (!recv_workqueue) {
log_print("can't start dlm_recv");
return -ENOMEM;
}
send_workqueue = alloc_ordered_workqueue("dlm_send", WQ_MEM_RECLAIM);
if (!send_workqueue) {
log_print("can't start dlm_send");
destroy_workqueue(recv_workqueue);
recv_workqueue = NULL;
return -ENOMEM;
}
return 0;
}
static void shutdown_conn(struct connection *con)
{
if (dlm_proto_ops->shutdown_action)
dlm_proto_ops->shutdown_action(con);
}
void dlm_lowcomms_shutdown(void)
{
int idx;
/* Set all the flags to prevent any
* socket activity.
*/
dlm_allow_conn = 0;
if (recv_workqueue)
flush_workqueue(recv_workqueue);
if (send_workqueue)
flush_workqueue(send_workqueue);
dlm_close_sock(&listen_con.sock);
idx = srcu_read_lock(&connections_srcu);
foreach_conn(shutdown_conn);
srcu_read_unlock(&connections_srcu, idx);
}
static void _stop_conn(struct connection *con, bool and_other)
{
mutex_lock(&con->sock_mutex);
set_bit(CF_CLOSE, &con->flags);
set_bit(CF_READ_PENDING, &con->flags);
set_bit(CF_WRITE_PENDING, &con->flags);
if (con->sock && con->sock->sk) {
write_lock_bh(&con->sock->sk->sk_callback_lock);
con->sock->sk->sk_user_data = NULL;
write_unlock_bh(&con->sock->sk->sk_callback_lock);
}
if (con->othercon && and_other)
_stop_conn(con->othercon, false);
mutex_unlock(&con->sock_mutex);
}
static void stop_conn(struct connection *con)
{
_stop_conn(con, true);
}
static void connection_release(struct rcu_head *rcu)
{
struct connection *con = container_of(rcu, struct connection, rcu);
kfree(con->rx_buf);
kfree(con);
}
static void free_conn(struct connection *con)
{
close_connection(con, true, true, true);
spin_lock(&connections_lock);
hlist_del_rcu(&con->list);
spin_unlock(&connections_lock);
if (con->othercon) {
clean_one_writequeue(con->othercon);
call_srcu(&connections_srcu, &con->othercon->rcu,
connection_release);
}
clean_one_writequeue(con);
call_srcu(&connections_srcu, &con->rcu, connection_release);
}
static void work_flush(void)
{
int ok;
int i;
struct connection *con;
do {
ok = 1;
foreach_conn(stop_conn);
if (recv_workqueue)
flush_workqueue(recv_workqueue);
if (send_workqueue)
flush_workqueue(send_workqueue);
for (i = 0; i < CONN_HASH_SIZE && ok; i++) {
hlist_for_each_entry_rcu(con, &connection_hash[i],
list) {
ok &= test_bit(CF_READ_PENDING, &con->flags);
ok &= test_bit(CF_WRITE_PENDING, &con->flags);
if (con->othercon) {
ok &= test_bit(CF_READ_PENDING,
&con->othercon->flags);
ok &= test_bit(CF_WRITE_PENDING,
&con->othercon->flags);
}
}
}
} while (!ok);
}
void dlm_lowcomms_stop(void)
{
int idx;
idx = srcu_read_lock(&connections_srcu);
work_flush();
foreach_conn(free_conn);
srcu_read_unlock(&connections_srcu, idx);
work_stop();
deinit_local();
dlm_proto_ops = NULL;
}
static int dlm_listen_for_all(void)
{
struct socket *sock;
int result;
log_print("Using %s for communications",
dlm_proto_ops->name);
result = dlm_proto_ops->listen_validate();
if (result < 0)
return result;
result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
SOCK_STREAM, dlm_proto_ops->proto, &sock);
if (result < 0) {
log_print("Can't create comms socket, check SCTP is loaded");
goto out;
}
sock_set_mark(sock->sk, dlm_config.ci_mark);
dlm_proto_ops->listen_sockopts(sock);
result = dlm_proto_ops->listen_bind(sock);
if (result < 0)
goto out;
save_listen_callbacks(sock);
add_listen_sock(sock, &listen_con);
INIT_WORK(&listen_con.rwork, process_listen_recv_socket);
result = sock->ops->listen(sock, 5);
if (result < 0) {
dlm_close_sock(&listen_con.sock);
goto out;
}
return 0;
out:
sock_release(sock);
return result;
}
static int dlm_tcp_bind(struct socket *sock)
{
struct sockaddr_storage src_addr;
int result, addr_len;
/* Bind to our cluster-known address connecting to avoid
* routing problems.
*/
memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr));
make_sockaddr(&src_addr, 0, &addr_len);
result = sock->ops->bind(sock, (struct sockaddr *)&src_addr,
addr_len);
if (result < 0) {
/* This *may* not indicate a critical error */
log_print("could not bind for connect: %d", result);
}
return 0;
}
static int dlm_tcp_connect(struct connection *con, struct socket *sock,
struct sockaddr *addr, int addr_len)
{
int ret;
ret = sock->ops->connect(sock, addr, addr_len, O_NONBLOCK);
switch (ret) {
case -EINPROGRESS:
fallthrough;
case 0:
return 0;
}
return ret;
}
static int dlm_tcp_listen_validate(void)
{
/* We don't support multi-homed hosts */
if (dlm_local_count > 1) {
log_print("TCP protocol can't handle multi-homed hosts, try SCTP");
return -EINVAL;
}
return 0;
}
static void dlm_tcp_sockopts(struct socket *sock)
{
/* Turn off Nagle's algorithm */
tcp_sock_set_nodelay(sock->sk);
}
static void dlm_tcp_listen_sockopts(struct socket *sock)
{
dlm_tcp_sockopts(sock);
sock_set_reuseaddr(sock->sk);
}
static int dlm_tcp_listen_bind(struct socket *sock)
{
int addr_len;
/* Bind to our port */
make_sockaddr(dlm_local_addr[0], dlm_config.ci_tcp_port, &addr_len);
return sock->ops->bind(sock, (struct sockaddr *)dlm_local_addr[0],
addr_len);
}
static const struct dlm_proto_ops dlm_tcp_ops = {
.name = "TCP",
.proto = IPPROTO_TCP,
.connect = dlm_tcp_connect,
.sockopts = dlm_tcp_sockopts,
.bind = dlm_tcp_bind,
.listen_validate = dlm_tcp_listen_validate,
.listen_sockopts = dlm_tcp_listen_sockopts,
.listen_bind = dlm_tcp_listen_bind,
.shutdown_action = dlm_tcp_shutdown,
.eof_condition = tcp_eof_condition,
};
static int dlm_sctp_bind(struct socket *sock)
{
return sctp_bind_addrs(sock, 0);
}
static int dlm_sctp_connect(struct connection *con, struct socket *sock,
struct sockaddr *addr, int addr_len)
{
int ret;
/*
* Make sock->ops->connect() function return in specified time,
* since O_NONBLOCK argument in connect() function does not work here,
* then, we should restore the default value of this attribute.
*/
sock_set_sndtimeo(sock->sk, 5);
ret = sock->ops->connect(sock, addr, addr_len, 0);
sock_set_sndtimeo(sock->sk, 0);
if (ret < 0)
return ret;
if (!test_and_set_bit(CF_CONNECTED, &con->flags))
log_print("successful connected to node %d", con->nodeid);
return 0;
}
static int dlm_sctp_listen_validate(void)
{
if (!IS_ENABLED(CONFIG_IP_SCTP)) {
log_print("SCTP is not enabled by this kernel");
return -EOPNOTSUPP;
}
request_module("sctp");
return 0;
}
static int dlm_sctp_bind_listen(struct socket *sock)
{
return sctp_bind_addrs(sock, dlm_config.ci_tcp_port);
}
static void dlm_sctp_sockopts(struct socket *sock)
{
/* Turn off Nagle's algorithm */
sctp_sock_set_nodelay(sock->sk);
sock_set_rcvbuf(sock->sk, NEEDED_RMEM);
}
static const struct dlm_proto_ops dlm_sctp_ops = {
.name = "SCTP",
.proto = IPPROTO_SCTP,
.try_new_addr = true,
.connect = dlm_sctp_connect,
.sockopts = dlm_sctp_sockopts,
.bind = dlm_sctp_bind,
.listen_validate = dlm_sctp_listen_validate,
.listen_sockopts = dlm_sctp_sockopts,
.listen_bind = dlm_sctp_bind_listen,
};
int dlm_lowcomms_start(void)
{
int error = -EINVAL;
int i;
for (i = 0; i < CONN_HASH_SIZE; i++)
INIT_HLIST_HEAD(&connection_hash[i]);
init_local();
if (!dlm_local_count) {
error = -ENOTCONN;
log_print("no local IP address has been set");
goto fail;
}
INIT_WORK(&listen_con.rwork, process_listen_recv_socket);
error = work_start();
if (error)
goto fail_local;
dlm_allow_conn = 1;
/* Start listening */
switch (dlm_config.ci_protocol) {
case DLM_PROTO_TCP:
dlm_proto_ops = &dlm_tcp_ops;
break;
case DLM_PROTO_SCTP:
dlm_proto_ops = &dlm_sctp_ops;
break;
default:
log_print("Invalid protocol identifier %d set",
dlm_config.ci_protocol);
error = -EINVAL;
goto fail_proto_ops;
}
error = dlm_listen_for_all();
if (error)
goto fail_listen;
return 0;
fail_listen:
dlm_proto_ops = NULL;
fail_proto_ops:
dlm_allow_conn = 0;
dlm_close_sock(&listen_con.sock);
work_stop();
fail_local:
deinit_local();
fail:
return error;
}
void dlm_lowcomms_exit(void)
{
struct dlm_node_addr *na, *safe;
spin_lock(&dlm_node_addrs_spin);
list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) {
list_del(&na->list);
while (na->addr_count--)
kfree(na->addr[na->addr_count]);
kfree(na);
}
spin_unlock(&dlm_node_addrs_spin);
}
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