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WSL2-Linux-Kernel/fs/dlm/lowcomms.c

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48 KiB
C
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// 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 <trace/events/dlm.h>
#include <trace/events/sock.h>
#include "dlm_internal.h"
#include "lowcomms.h"
#include "midcomms.h"
#include "memory.h"
#include "config.h"
#define DLM_SHUTDOWN_WAIT_TIMEOUT msecs_to_jiffies(5000)
#define NEEDED_RMEM (4*1024*1024)
struct connection {
struct socket *sock; /* NULL if not connected */
uint32_t nodeid; /* So we know who we are in the list */
/* this semaphore is used to allow parallel recv/send in read
* lock mode. When we release a sock we need to held the write lock.
*
* However this is locking code and not nice. When we remove the
* othercon handling we can look into other mechanism to synchronize
* io handling to call sock_release() at the right time.
*/
struct rw_semaphore sock_lock;
unsigned long flags;
#define CF_APP_LIMITED 0
#define CF_RECV_PENDING 1
#define CF_SEND_PENDING 2
#define CF_RECV_INTR 3
#define CF_IO_STOP 4
#define CF_IS_OTHERCON 5
struct list_head writequeue; /* List of outgoing writequeue_entries */
spinlock_t writequeue_lock;
int retries;
struct hlist_node list;
/* due some connect()/accept() races we currently have this cross over
* connection attempt second connection for one node.
*
* There is a solution to avoid the race by introducing a connect
* rule as e.g. our_nodeid > nodeid_to_connect who is allowed to
* connect. Otherside can connect but will only be considered that
* the other side wants to have a reconnect.
*
* However changing to this behaviour will break backwards compatible.
* In a DLM protocol major version upgrade we should remove this!
*/
struct connection *othercon;
struct work_struct rwork; /* receive worker */
struct work_struct swork; /* send worker */
wait_queue_head_t shutdown_wait;
unsigned char rx_leftover_buf[DLM_MAX_SOCKET_BUFSIZE];
int rx_leftover;
int mark;
int addr_count;
int curr_addr_index;
struct sockaddr_storage addr[DLM_MAX_ADDR_COUNT];
spinlock_t addrs_lock;
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 processqueue_entry {
unsigned char *buf;
int nodeid;
int buflen;
struct list_head list;
};
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);
};
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 struct listen_connection listen_con;
static struct sockaddr_storage dlm_local_addr[DLM_MAX_ADDR_COUNT];
static int dlm_local_count;
/* Work queues */
static struct workqueue_struct *io_workqueue;
static struct workqueue_struct *process_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;
#define DLM_IO_SUCCESS 0
#define DLM_IO_END 1
#define DLM_IO_EOF 2
#define DLM_IO_RESCHED 3
static void process_recv_sockets(struct work_struct *work);
static void process_send_sockets(struct work_struct *work);
static void process_dlm_messages(struct work_struct *work);
static DECLARE_WORK(process_work, process_dlm_messages);
static DEFINE_SPINLOCK(processqueue_lock);
static bool process_dlm_messages_pending;
static LIST_HEAD(processqueue);
bool dlm_lowcomms_is_running(void)
{
return !!listen_con.sock;
}
static void lowcomms_queue_swork(struct connection *con)
{
assert_spin_locked(&con->writequeue_lock);
if (!test_bit(CF_IO_STOP, &con->flags) &&
!test_bit(CF_APP_LIMITED, &con->flags) &&
!test_and_set_bit(CF_SEND_PENDING, &con->flags))
queue_work(io_workqueue, &con->swork);
}
static void lowcomms_queue_rwork(struct connection *con)
{
#ifdef CONFIG_LOCKDEP
WARN_ON_ONCE(!lockdep_sock_is_held(con->sock->sk));
#endif
if (!test_bit(CF_IO_STOP, &con->flags) &&
!test_and_set_bit(CF_RECV_PENDING, &con->flags))
queue_work(io_workqueue, &con->rwork);
}
static void writequeue_entry_ctor(void *data)
{
struct writequeue_entry *entry = data;
INIT_LIST_HEAD(&entry->msgs);
}
struct kmem_cache *dlm_lowcomms_writequeue_cache_create(void)
{
return kmem_cache_create("dlm_writequeue", sizeof(struct writequeue_entry),
0, 0, writequeue_entry_ctor);
}
struct kmem_cache *dlm_lowcomms_msg_cache_create(void)
{
return kmem_cache_create("dlm_msg", sizeof(struct dlm_msg), 0, 0, NULL);
}
/* need to held writequeue_lock */
static struct writequeue_entry *con_next_wq(struct connection *con)
{
struct writequeue_entry *e;
e = list_first_entry_or_null(&con->writequeue, struct writequeue_entry,
list);
/* if len is zero nothing is to send, if there are users filling
* buffers we wait until the users are done so we can send more.
*/
if (!e || e->users || 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 void dlm_con_init(struct connection *con, int nodeid)
{
con->nodeid = nodeid;
init_rwsem(&con->sock_lock);
INIT_LIST_HEAD(&con->writequeue);
spin_lock_init(&con->writequeue_lock);
INIT_WORK(&con->swork, process_send_sockets);
INIT_WORK(&con->rwork, process_recv_sockets);
spin_lock_init(&con->addrs_lock);
init_waitqueue_head(&con->shutdown_wait);
}
/*
* 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;
r = nodeid_hash(nodeid);
con = __find_con(nodeid, r);
if (con || !alloc)
return con;
con = kzalloc(sizeof(*con), alloc);
if (!con)
return NULL;
dlm_con_init(con, nodeid);
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);
return tmp;
}
hlist_add_head_rcu(&con->list, &connection_hash[r]);
spin_unlock(&connections_lock);
return con;
}
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 connection *con;
int idx;
if (!dlm_local_count)
return -1;
idx = srcu_read_lock(&connections_srcu);
con = nodeid2con(nodeid, 0);
if (!con) {
srcu_read_unlock(&connections_srcu, idx);
return -ENOENT;
}
spin_lock(&con->addrs_lock);
if (!con->addr_count) {
spin_unlock(&con->addrs_lock);
srcu_read_unlock(&connections_srcu, idx);
return -ENOENT;
}
memcpy(&sas, &con->addr[con->curr_addr_index],
sizeof(struct sockaddr_storage));
if (try_new_addr) {
con->curr_addr_index++;
if (con->curr_addr_index == con->addr_count)
con->curr_addr_index = 0;
}
*mark = con->mark;
spin_unlock(&con->addrs_lock);
if (sas_out)
memcpy(sas_out, &sas, sizeof(struct sockaddr_storage));
if (!sa_out) {
srcu_read_unlock(&connections_srcu, idx);
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;
}
srcu_read_unlock(&connections_srcu, idx);
return 0;
}
static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid,
unsigned int *mark)
{
struct connection *con;
int i, idx, addr_i;
idx = srcu_read_lock(&connections_srcu);
for (i = 0; i < CONN_HASH_SIZE; i++) {
hlist_for_each_entry_rcu(con, &connection_hash[i], list) {
WARN_ON_ONCE(!con->addr_count);
spin_lock(&con->addrs_lock);
for (addr_i = 0; addr_i < con->addr_count; addr_i++) {
if (addr_compare(&con->addr[addr_i], addr)) {
*nodeid = con->nodeid;
*mark = con->mark;
spin_unlock(&con->addrs_lock);
srcu_read_unlock(&connections_srcu, idx);
return 0;
}
}
spin_unlock(&con->addrs_lock);
}
}
srcu_read_unlock(&connections_srcu, idx);
return -ENOENT;
}
static bool dlm_lowcomms_con_has_addr(const struct connection *con,
const struct sockaddr_storage *addr)
{
int i;
for (i = 0; i < con->addr_count; i++) {
if (addr_compare(&con->addr[i], addr))
return true;
}
return false;
}
int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len)
{
struct connection *con;
bool ret, idx;
idx = srcu_read_lock(&connections_srcu);
con = nodeid2con(nodeid, GFP_NOFS);
if (!con) {
srcu_read_unlock(&connections_srcu, idx);
return -ENOMEM;
}
spin_lock(&con->addrs_lock);
if (!con->addr_count) {
memcpy(&con->addr[0], addr, sizeof(*addr));
con->addr_count = 1;
con->mark = dlm_config.ci_mark;
spin_unlock(&con->addrs_lock);
srcu_read_unlock(&connections_srcu, idx);
return 0;
}
ret = dlm_lowcomms_con_has_addr(con, addr);
if (ret) {
spin_unlock(&con->addrs_lock);
srcu_read_unlock(&connections_srcu, idx);
return -EEXIST;
}
if (con->addr_count >= DLM_MAX_ADDR_COUNT) {
spin_unlock(&con->addrs_lock);
srcu_read_unlock(&connections_srcu, idx);
return -ENOSPC;
}
memcpy(&con->addr[con->addr_count++], addr, sizeof(*addr));
srcu_read_unlock(&connections_srcu, idx);
spin_unlock(&con->addrs_lock);
return 0;
}
/* Data available on socket or listen socket received a connect */
static void lowcomms_data_ready(struct sock *sk)
{
struct connection *con = sock2con(sk);
trace_sk_data_ready(sk);
set_bit(CF_RECV_INTR, &con->flags);
lowcomms_queue_rwork(con);
}
static void lowcomms_write_space(struct sock *sk)
{
struct connection *con = sock2con(sk);
clear_bit(SOCK_NOSPACE, &con->sock->flags);
spin_lock_bh(&con->writequeue_lock);
if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) {
con->sock->sk->sk_write_pending--;
clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags);
}
lowcomms_queue_swork(con);
spin_unlock_bh(&con->writequeue_lock);
}
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.
*/
if (sk->sk_shutdown == RCV_SHUTDOWN)
lowcomms_data_ready(sk);
}
static void lowcomms_listen_data_ready(struct sock *sk)
{
trace_sk_data_ready(sk);
queue_work(io_workqueue, &listen_con.rwork);
}
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, 0);
if (WARN_ON_ONCE(!con)) {
srcu_read_unlock(&connections_srcu, idx);
return -ENOENT;
}
down_read(&con->sock_lock);
if (!con->sock) {
spin_lock_bh(&con->writequeue_lock);
lowcomms_queue_swork(con);
spin_unlock_bh(&con->writequeue_lock);
}
up_read(&con->sock_lock);
srcu_read_unlock(&connections_srcu, idx);
cond_resched();
return 0;
}
int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark)
{
struct connection *con;
int idx;
idx = srcu_read_lock(&connections_srcu);
con = nodeid2con(nodeid, 0);
if (!con) {
srcu_read_unlock(&connections_srcu, idx);
return -ENOENT;
}
spin_lock(&con->addrs_lock);
con->mark = mark;
spin_unlock(&con->addrs_lock);
srcu_read_unlock(&connections_srcu, idx);
return 0;
}
static void lowcomms_error_report(struct sock *sk)
{
struct connection *con = sock2con(sk);
struct inet_sock *inet;
inet = inet_sk(sk);
switch (sk->sk_family) {
case AF_INET:
printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
"sending to node %d at %pI4, dport %d, "
"sk_err=%d/%d\n", dlm_our_nodeid(),
con->nodeid, &inet->inet_daddr,
ntohs(inet->inet_dport), sk->sk_err,
sk->sk_err_soft);
break;
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6:
printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
"sending to node %d at %pI6c, "
"dport %d, sk_err=%d/%d\n", dlm_our_nodeid(),
con->nodeid, &sk->sk_v6_daddr,
ntohs(inet->inet_dport), sk->sk_err,
sk->sk_err_soft);
break;
#endif
default:
printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
"invalid socket family %d set, "
"sk_err=%d/%d\n", dlm_our_nodeid(),
sk->sk_family, sk->sk_err, sk->sk_err_soft);
break;
}
dlm_midcomms_unack_msg_resend(con->nodeid);
listen_sock.sk_error_report(sk);
}
static void restore_callbacks(struct sock *sk)
{
#ifdef CONFIG_LOCKDEP
WARN_ON_ONCE(!lockdep_sock_is_held(sk));
#endif
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;
}
/* Make a socket active */
static void add_sock(struct socket *sock, struct connection *con)
{
struct sock *sk = sock->sk;
lock_sock(sk);
con->sock = sock;
sk->sk_user_data = con;
sk->sk_data_ready = lowcomms_data_ready;
sk->sk_write_space = lowcomms_write_space;
if (dlm_config.ci_protocol == DLM_PROTO_SCTP)
sk->sk_state_change = lowcomms_state_change;
sk->sk_allocation = GFP_NOFS;
sk->sk_use_task_frag = false;
sk->sk_error_report = lowcomms_error_report;
release_sock(sk);
}
/* 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);
dlm_free_writequeue(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);
dlm_free_msg(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);
kref_put(&e->ref, dlm_page_release);
}
static void dlm_close_sock(struct socket **sock)
{
lock_sock((*sock)->sk);
restore_callbacks((*sock)->sk);
release_sock((*sock)->sk);
sock_release(*sock);
*sock = NULL;
}
static void allow_connection_io(struct connection *con)
{
if (con->othercon)
clear_bit(CF_IO_STOP, &con->othercon->flags);
clear_bit(CF_IO_STOP, &con->flags);
}
static void stop_connection_io(struct connection *con)
{
if (con->othercon)
stop_connection_io(con->othercon);
down_write(&con->sock_lock);
if (con->sock) {
lock_sock(con->sock->sk);
restore_callbacks(con->sock->sk);
spin_lock_bh(&con->writequeue_lock);
set_bit(CF_IO_STOP, &con->flags);
spin_unlock_bh(&con->writequeue_lock);
release_sock(con->sock->sk);
} else {
spin_lock_bh(&con->writequeue_lock);
set_bit(CF_IO_STOP, &con->flags);
spin_unlock_bh(&con->writequeue_lock);
}
up_write(&con->sock_lock);
cancel_work_sync(&con->swork);
cancel_work_sync(&con->rwork);
}
/* Close a remote connection and tidy up */
static void close_connection(struct connection *con, bool and_other)
{
struct writequeue_entry *e;
if (con->othercon && and_other)
close_connection(con->othercon, false);
down_write(&con->sock_lock);
if (!con->sock) {
up_write(&con->sock_lock);
return;
}
dlm_close_sock(&con->sock);
/* 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_bh(&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_bh(&con->writequeue_lock);
con->rx_leftover = 0;
con->retries = 0;
clear_bit(CF_APP_LIMITED, &con->flags);
clear_bit(CF_RECV_PENDING, &con->flags);
clear_bit(CF_SEND_PENDING, &con->flags);
up_write(&con->sock_lock);
}
static void shutdown_connection(struct connection *con, bool and_other)
{
int ret;
if (con->othercon && and_other)
shutdown_connection(con->othercon, false);
flush_workqueue(io_workqueue);
down_read(&con->sock_lock);
/* nothing to shutdown */
if (!con->sock) {
up_read(&con->sock_lock);
return;
}
ret = kernel_sock_shutdown(con->sock, SHUT_WR);
up_read(&con->sock_lock);
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, !con->sock,
DLM_SHUTDOWN_WAIT_TIMEOUT);
if (ret == 0) {
log_print("Connection %p shutdown timed out, will force close",
con);
goto force_close;
}
}
return;
force_close:
close_connection(con, false);
}
static struct processqueue_entry *new_processqueue_entry(int nodeid,
int buflen)
{
struct processqueue_entry *pentry;
pentry = kmalloc(sizeof(*pentry), GFP_NOFS);
if (!pentry)
return NULL;
pentry->buf = kmalloc(buflen, GFP_NOFS);
if (!pentry->buf) {
kfree(pentry);
return NULL;
}
pentry->nodeid = nodeid;
return pentry;
}
static void free_processqueue_entry(struct processqueue_entry *pentry)
{
kfree(pentry->buf);
kfree(pentry);
}
struct dlm_processed_nodes {
int nodeid;
struct list_head list;
};
static void add_processed_node(int nodeid, struct list_head *processed_nodes)
{
struct dlm_processed_nodes *n;
list_for_each_entry(n, processed_nodes, list) {
/* we already remembered this node */
if (n->nodeid == nodeid)
return;
}
/* if it's fails in worst case we simple don't send an ack back.
* We try it next time.
*/
n = kmalloc(sizeof(*n), GFP_NOFS);
if (!n)
return;
n->nodeid = nodeid;
list_add(&n->list, processed_nodes);
}
static void process_dlm_messages(struct work_struct *work)
{
struct dlm_processed_nodes *n, *n_tmp;
struct processqueue_entry *pentry;
LIST_HEAD(processed_nodes);
spin_lock(&processqueue_lock);
pentry = list_first_entry_or_null(&processqueue,
struct processqueue_entry, list);
if (WARN_ON_ONCE(!pentry)) {
spin_unlock(&processqueue_lock);
return;
}
list_del(&pentry->list);
spin_unlock(&processqueue_lock);
for (;;) {
dlm_process_incoming_buffer(pentry->nodeid, pentry->buf,
pentry->buflen);
add_processed_node(pentry->nodeid, &processed_nodes);
free_processqueue_entry(pentry);
spin_lock(&processqueue_lock);
pentry = list_first_entry_or_null(&processqueue,
struct processqueue_entry, list);
if (!pentry) {
process_dlm_messages_pending = false;
spin_unlock(&processqueue_lock);
break;
}
list_del(&pentry->list);
spin_unlock(&processqueue_lock);
}
/* send ack back after we processed couple of messages */
list_for_each_entry_safe(n, n_tmp, &processed_nodes, list) {
list_del(&n->list);
dlm_midcomms_receive_done(n->nodeid);
kfree(n);
}
}
/* Data received from remote end */
static int receive_from_sock(struct connection *con, int buflen)
{
struct processqueue_entry *pentry;
int ret, buflen_real;
struct msghdr msg;
struct kvec iov;
pentry = new_processqueue_entry(con->nodeid, buflen);
if (!pentry)
return DLM_IO_RESCHED;
memcpy(pentry->buf, con->rx_leftover_buf, con->rx_leftover);
/* calculate new buffer parameter regarding last receive and
* possible leftover bytes
*/
iov.iov_base = pentry->buf + con->rx_leftover;
iov.iov_len = buflen - con->rx_leftover;
memset(&msg, 0, sizeof(msg));
msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
clear_bit(CF_RECV_INTR, &con->flags);
again:
ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len,
msg.msg_flags);
trace_dlm_recv(con->nodeid, ret);
if (ret == -EAGAIN) {
lock_sock(con->sock->sk);
if (test_and_clear_bit(CF_RECV_INTR, &con->flags)) {
release_sock(con->sock->sk);
goto again;
}
clear_bit(CF_RECV_PENDING, &con->flags);
release_sock(con->sock->sk);
free_processqueue_entry(pentry);
return DLM_IO_END;
} else if (ret == 0) {
/* close will clear CF_RECV_PENDING */
free_processqueue_entry(pentry);
return DLM_IO_EOF;
} else if (ret < 0) {
free_processqueue_entry(pentry);
return ret;
}
/* new buflen according readed bytes and leftover from last receive */
buflen_real = ret + con->rx_leftover;
ret = dlm_validate_incoming_buffer(con->nodeid, pentry->buf,
buflen_real);
if (ret < 0) {
free_processqueue_entry(pentry);
return ret;
}
pentry->buflen = ret;
/* 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_real - ret;
memmove(con->rx_leftover_buf, pentry->buf + ret,
con->rx_leftover);
spin_lock(&processqueue_lock);
list_add_tail(&pentry->list, &processqueue);
if (!process_dlm_messages_pending) {
process_dlm_messages_pending = true;
queue_work(process_workqueue, &process_work);
}
spin_unlock(&processqueue_lock);
return DLM_IO_SUCCESS;
}
/* Listening socket is busy, accept a connection */
static int accept_from_sock(void)
{
struct sockaddr_storage peeraddr;
int len, idx, result, nodeid;
struct connection *newcon;
struct socket *newsock;
unsigned int mark;
result = kernel_accept(listen_con.sock, &newsock, O_NONBLOCK);
if (result == -EAGAIN)
return DLM_IO_END;
else 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)) {
switch (peeraddr.ss_family) {
case AF_INET: {
struct sockaddr_in *sin = (struct sockaddr_in *)&peeraddr;
log_print("connect from non cluster IPv4 node %pI4",
&sin->sin_addr);
break;
}
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6: {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&peeraddr;
log_print("connect from non cluster IPv6 node %pI6c",
&sin6->sin6_addr);
break;
}
#endif
default:
log_print("invalid family from non cluster node");
break;
}
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, 0);
if (WARN_ON_ONCE(!newcon)) {
srcu_read_unlock(&connections_srcu, idx);
result = -ENOENT;
goto accept_err;
}
sock_set_mark(newsock->sk, mark);
down_write(&newcon->sock_lock);
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");
up_write(&newcon->sock_lock);
srcu_read_unlock(&connections_srcu, idx);
result = -ENOMEM;
goto accept_err;
}
dlm_con_init(othercon, nodeid);
lockdep_set_subclass(&othercon->sock_lock, 1);
newcon->othercon = othercon;
set_bit(CF_IS_OTHERCON, &othercon->flags);
} else {
/* close other sock con if we have something new */
close_connection(othercon, false);
}
down_write(&othercon->sock_lock);
add_sock(newsock, othercon);
/* check if we receved something while adding */
lock_sock(othercon->sock->sk);
lowcomms_queue_rwork(othercon);
release_sock(othercon->sock->sk);
up_write(&othercon->sock_lock);
}
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);
/* check if we receved something while adding */
lock_sock(newcon->sock->sk);
lowcomms_queue_rwork(newcon);
release_sock(newcon->sock->sk);
}
up_write(&newcon->sock_lock);
srcu_read_unlock(&connections_srcu, idx);
return DLM_IO_SUCCESS;
accept_err:
if (newsock)
sock_release(newsock);
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;
int i;
dlm_local_count = 0;
for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) {
if (dlm_our_addr(&sas, i))
break;
memcpy(&dlm_local_addr[dlm_local_count++], &sas, sizeof(sas));
}
}
static struct writequeue_entry *new_writequeue_entry(struct connection *con)
{
struct writequeue_entry *entry;
entry = dlm_allocate_writequeue();
if (!entry)
return NULL;
entry->page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
if (!entry->page) {
dlm_free_writequeue(entry);
return NULL;
}
entry->offset = 0;
entry->len = 0;
entry->end = 0;
entry->dirty = false;
entry->con = con;
entry->users = 1;
kref_init(&entry->ref);
return entry;
}
static struct writequeue_entry *new_wq_entry(struct connection *con, int len,
char **ppc, void (*cb)(void *data),
void *data)
{
struct writequeue_entry *e;
spin_lock_bh(&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(data);
e->end += len;
e->users++;
goto out;
}
}
e = new_writequeue_entry(con);
if (!e)
goto out;
kref_get(&e->ref);
*ppc = page_address(e->page);
e->end += len;
if (cb)
cb(data);
list_add_tail(&e->list, &con->writequeue);
out:
spin_unlock_bh(&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)(void *data),
void *data)
{
struct writequeue_entry *e;
struct dlm_msg *msg;
msg = dlm_allocate_msg(allocation);
if (!msg)
return NULL;
kref_init(&msg->ref);
e = new_wq_entry(con, len, ppc, cb, data);
if (!e) {
dlm_free_msg(msg);
return NULL;
}
msg->retransmit = false;
msg->orig_msg = NULL;
msg->ppc = *ppc;
msg->len = len;
msg->entry = e;
return msg;
}
/* avoid false positive for nodes_srcu, unlock happens in
* dlm_lowcomms_commit_msg which is a must call if success
*/
#ifndef __CHECKER__
struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation,
char **ppc, void (*cb)(void *data),
void *data)
{
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_ONCE(1);
return NULL;
}
idx = srcu_read_lock(&connections_srcu);
con = nodeid2con(nodeid, 0);
if (WARN_ON_ONCE(!con)) {
srcu_read_unlock(&connections_srcu, idx);
return NULL;
}
msg = dlm_lowcomms_new_msg_con(con, len, allocation, ppc, cb, data);
if (!msg) {
srcu_read_unlock(&connections_srcu, idx);
return NULL;
}
/* for dlm_lowcomms_commit_msg() */
kref_get(&msg->ref);
/* we assume if successful commit must called */
msg->idx = idx;
return msg;
}
#endif
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_bh(&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);
lowcomms_queue_swork(con);
out:
spin_unlock_bh(&con->writequeue_lock);
return;
}
/* avoid false positive for nodes_srcu, lock was happen in
* dlm_lowcomms_new_msg
*/
#ifndef __CHECKER__
void dlm_lowcomms_commit_msg(struct dlm_msg *msg)
{
_dlm_lowcomms_commit_msg(msg);
srcu_read_unlock(&connections_srcu, msg->idx);
/* because dlm_lowcomms_new_msg() */
kref_put(&msg->ref, dlm_msg_release);
}
#endif
void dlm_lowcomms_put_msg(struct dlm_msg *msg)
{
kref_put(&msg->ref, dlm_msg_release);
}
/* does not held connections_srcu, usage lowcomms_error_report 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 int send_to_sock(struct connection *con)
{
const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
struct writequeue_entry *e;
int len, offset, ret;
spin_lock_bh(&con->writequeue_lock);
e = con_next_wq(con);
if (!e) {
clear_bit(CF_SEND_PENDING, &con->flags);
spin_unlock_bh(&con->writequeue_lock);
return DLM_IO_END;
}
len = e->len;
offset = e->offset;
WARN_ON_ONCE(len == 0 && e->users == 0);
spin_unlock_bh(&con->writequeue_lock);
ret = kernel_sendpage(con->sock, e->page, offset, len,
msg_flags);
trace_dlm_send(con->nodeid, ret);
if (ret == -EAGAIN || ret == 0) {
lock_sock(con->sock->sk);
spin_lock_bh(&con->writequeue_lock);
if (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->sk->sk_socket->flags);
con->sock->sk->sk_write_pending++;
clear_bit(CF_SEND_PENDING, &con->flags);
spin_unlock_bh(&con->writequeue_lock);
release_sock(con->sock->sk);
/* wait for write_space() event */
return DLM_IO_END;
}
spin_unlock_bh(&con->writequeue_lock);
release_sock(con->sock->sk);
return DLM_IO_RESCHED;
} else if (ret < 0) {
return ret;
}
spin_lock_bh(&con->writequeue_lock);
writequeue_entry_complete(e, ret);
spin_unlock_bh(&con->writequeue_lock);
return DLM_IO_SUCCESS;
}
static void clean_one_writequeue(struct connection *con)
{
struct writequeue_entry *e, *safe;
spin_lock_bh(&con->writequeue_lock);
list_for_each_entry_safe(e, safe, &con->writequeue, list) {
free_entry(e);
}
spin_unlock_bh(&con->writequeue_lock);
}
static void connection_release(struct rcu_head *rcu)
{
struct connection *con = container_of(rcu, struct connection, rcu);
WARN_ON_ONCE(!list_empty(&con->writequeue));
WARN_ON_ONCE(con->sock);
kfree(con);
}
/* Called from recovery when it knows that a node has
left the cluster */
int dlm_lowcomms_close(int nodeid)
{
struct connection *con;
int idx;
log_print("closing connection to node %d", nodeid);
idx = srcu_read_lock(&connections_srcu);
con = nodeid2con(nodeid, 0);
if (WARN_ON_ONCE(!con)) {
srcu_read_unlock(&connections_srcu, idx);
return -ENOENT;
}
stop_connection_io(con);
log_print("io handling for node: %d stopped", nodeid);
close_connection(con, true);
spin_lock(&connections_lock);
hlist_del_rcu(&con->list);
spin_unlock(&connections_lock);
clean_one_writequeue(con);
call_srcu(&connections_srcu, &con->rcu, connection_release);
if (con->othercon) {
clean_one_writequeue(con->othercon);
if (con->othercon)
call_srcu(&connections_srcu, &con->othercon->rcu, connection_release);
}
srcu_read_unlock(&connections_srcu, idx);
/* for debugging we print when we are done to compare with other
* messages in between. This function need to be correctly synchronized
* with io handling
*/
log_print("closing connection to node %d done", nodeid);
return 0;
}
/* Receive worker function */
static void process_recv_sockets(struct work_struct *work)
{
struct connection *con = container_of(work, struct connection, rwork);
int ret, buflen;
down_read(&con->sock_lock);
if (!con->sock) {
up_read(&con->sock_lock);
return;
}
buflen = READ_ONCE(dlm_config.ci_buffer_size);
do {
ret = receive_from_sock(con, buflen);
} while (ret == DLM_IO_SUCCESS);
up_read(&con->sock_lock);
switch (ret) {
case DLM_IO_END:
/* CF_RECV_PENDING cleared */
break;
case DLM_IO_EOF:
close_connection(con, false);
wake_up(&con->shutdown_wait);
/* CF_RECV_PENDING cleared */
break;
case DLM_IO_RESCHED:
cond_resched();
queue_work(io_workqueue, &con->rwork);
/* CF_RECV_PENDING not cleared */
break;
default:
if (ret < 0) {
if (test_bit(CF_IS_OTHERCON, &con->flags)) {
close_connection(con, false);
} else {
spin_lock_bh(&con->writequeue_lock);
lowcomms_queue_swork(con);
spin_unlock_bh(&con->writequeue_lock);
}
/* CF_RECV_PENDING cleared for othercon
* we trigger send queue if not already done
* and process_send_sockets will handle it
*/
break;
}
WARN_ON_ONCE(1);
break;
}
}
static void process_listen_recv_socket(struct work_struct *work)
{
int ret;
if (WARN_ON_ONCE(!listen_con.sock))
return;
do {
ret = accept_from_sock();
} while (ret == DLM_IO_SUCCESS);
if (ret < 0)
log_print("critical error accepting connection: %d", ret);
}
static int dlm_connect(struct connection *con)
{
struct sockaddr_storage addr;
int result, addr_len;
struct socket *sock;
unsigned int mark;
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 result;
}
/* 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)
return result;
sock_set_mark(sock->sk, mark);
dlm_proto_ops->sockopts(sock);
result = dlm_proto_ops->bind(sock);
if (result < 0) {
sock_release(sock);
return result;
}
add_sock(sock, con);
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);
switch (result) {
case -EINPROGRESS:
/* not an error */
fallthrough;
case 0:
break;
default:
if (result < 0)
dlm_close_sock(&con->sock);
break;
}
return result;
}
/* Send worker function */
static void process_send_sockets(struct work_struct *work)
{
struct connection *con = container_of(work, struct connection, swork);
int ret;
WARN_ON_ONCE(test_bit(CF_IS_OTHERCON, &con->flags));
down_read(&con->sock_lock);
if (!con->sock) {
up_read(&con->sock_lock);
down_write(&con->sock_lock);
if (!con->sock) {
ret = dlm_connect(con);
switch (ret) {
case 0:
break;
case -EINPROGRESS:
/* avoid spamming resched on connection
* we might can switch to a state_change
* event based mechanism if established
*/
msleep(100);
break;
default:
/* CF_SEND_PENDING not cleared */
up_write(&con->sock_lock);
log_print("connect to node %d try %d error %d",
con->nodeid, con->retries++, ret);
msleep(1000);
/* For now we try forever to reconnect. In
* future we should send a event to cluster
* manager to fence itself after certain amount
* of retries.
*/
queue_work(io_workqueue, &con->swork);
return;
}
}
downgrade_write(&con->sock_lock);
}
do {
ret = send_to_sock(con);
} while (ret == DLM_IO_SUCCESS);
up_read(&con->sock_lock);
switch (ret) {
case DLM_IO_END:
/* CF_SEND_PENDING cleared */
break;
case DLM_IO_RESCHED:
/* CF_SEND_PENDING not cleared */
cond_resched();
queue_work(io_workqueue, &con->swork);
break;
default:
if (ret < 0) {
close_connection(con, false);
/* CF_SEND_PENDING cleared */
spin_lock_bh(&con->writequeue_lock);
lowcomms_queue_swork(con);
spin_unlock_bh(&con->writequeue_lock);
break;
}
WARN_ON_ONCE(1);
break;
}
}
static void work_stop(void)
{
if (io_workqueue) {
destroy_workqueue(io_workqueue);
io_workqueue = NULL;
}
if (process_workqueue) {
destroy_workqueue(process_workqueue);
process_workqueue = NULL;
}
}
static int work_start(void)
{
io_workqueue = alloc_workqueue("dlm_io", WQ_HIGHPRI | WQ_MEM_RECLAIM,
0);
if (!io_workqueue) {
log_print("can't start dlm_io");
return -ENOMEM;
}
/* ordered dlm message process queue,
* should be converted to a tasklet
*/
process_workqueue = alloc_ordered_workqueue("dlm_process",
WQ_HIGHPRI | WQ_MEM_RECLAIM);
if (!process_workqueue) {
log_print("can't start dlm_process");
destroy_workqueue(io_workqueue);
io_workqueue = NULL;
return -ENOMEM;
}
return 0;
}
void dlm_lowcomms_shutdown(void)
{
struct connection *con;
int i, idx;
/* stop lowcomms_listen_data_ready calls */
lock_sock(listen_con.sock->sk);
listen_con.sock->sk->sk_data_ready = listen_sock.sk_data_ready;
release_sock(listen_con.sock->sk);
cancel_work_sync(&listen_con.rwork);
dlm_close_sock(&listen_con.sock);
idx = srcu_read_lock(&connections_srcu);
for (i = 0; i < CONN_HASH_SIZE; i++) {
hlist_for_each_entry_rcu(con, &connection_hash[i], list) {
shutdown_connection(con, true);
stop_connection_io(con);
flush_workqueue(process_workqueue);
close_connection(con, true);
clean_one_writequeue(con);
if (con->othercon)
clean_one_writequeue(con->othercon);
allow_connection_io(con);
}
}
srcu_read_unlock(&connections_srcu, idx);
}
void dlm_lowcomms_stop(void)
{
work_stop();
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: %d", result);
return result;
}
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;
lock_sock(sock->sk);
listen_sock.sk_data_ready = sock->sk->sk_data_ready;
listen_sock.sk_write_space = sock->sk->sk_write_space;
listen_sock.sk_error_report = sock->sk->sk_error_report;
listen_sock.sk_state_change = sock->sk->sk_state_change;
listen_con.sock = sock;
sock->sk->sk_allocation = GFP_NOFS;
sock->sk->sk_use_task_frag = false;
sock->sk->sk_data_ready = lowcomms_listen_data_ready;
release_sock(sock->sk);
result = sock->ops->listen(sock, 5);
if (result < 0) {
dlm_close_sock(&listen_con.sock);
return result;
}
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)
{
return sock->ops->connect(sock, addr, addr_len, O_NONBLOCK);
}
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,
};
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);
return ret;
}
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;
init_local();
if (!dlm_local_count) {
error = -ENOTCONN;
log_print("no local IP address has been set");
goto fail;
}
error = work_start();
if (error)
goto fail;
/* 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:
work_stop();
fail:
return error;
}
void dlm_lowcomms_init(void)
{
int i;
for (i = 0; i < CONN_HASH_SIZE; i++)
INIT_HLIST_HEAD(&connection_hash[i]);
INIT_WORK(&listen_con.rwork, process_listen_recv_socket);
}
void dlm_lowcomms_exit(void)
{
struct connection *con;
int i, idx;
idx = srcu_read_lock(&connections_srcu);
for (i = 0; i < CONN_HASH_SIZE; i++) {
hlist_for_each_entry_rcu(con, &connection_hash[i], list) {
spin_lock(&connections_lock);
hlist_del_rcu(&con->list);
spin_unlock(&connections_lock);
if (con->othercon)
call_srcu(&connections_srcu, &con->othercon->rcu,
connection_release);
call_srcu(&connections_srcu, &con->rcu, connection_release);
}
}
srcu_read_unlock(&connections_srcu, idx);
}
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