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![Al Viro](/assets/img/avatar_default.png)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1007 lines
23 KiB
C
1007 lines
23 KiB
C
/******************************************************************************
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*******************************************************************************
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**
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** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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** Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
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**
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** This copyrighted material is made available to anyone wishing to use,
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** modify, copy, or redistribute it subject to the terms and conditions
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** of the GNU General Public License v.2.
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**
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*******************************************************************************
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******************************************************************************/
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/*
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* lowcomms.c
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*
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* This is the "low-level" comms layer.
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*
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* It is responsible for sending/receiving messages
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* from other nodes in the cluster.
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*
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* Cluster nodes are referred to by their nodeids. nodeids are
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* simply 32 bit numbers to the locking module - if they need to
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* be expanded for the cluster infrastructure then that is it's
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* responsibility. It is this layer's
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* responsibility to resolve these into IP address or
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* whatever it needs for inter-node communication.
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*
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* The comms level is two kernel threads that deal mainly with
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* the receiving of messages from other nodes and passing them
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* up to the mid-level comms layer (which understands the
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* message format) for execution by the locking core, and
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* a send thread which does all the setting up of connections
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* to remote nodes and the sending of data. Threads are not allowed
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* to send their own data because it may cause them to wait in times
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* of high load. Also, this way, the sending thread can collect together
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* messages bound for one node and send them in one block.
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*
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* I don't see any problem with the recv thread executing the locking
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* code on behalf of remote processes as the locking code is
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* short, efficient and never waits.
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*
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*/
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#include <asm/ioctls.h>
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#include <net/sock.h>
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#include <net/tcp.h>
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#include <linux/pagemap.h>
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#include "dlm_internal.h"
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#include "lowcomms.h"
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#include "midcomms.h"
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#include "config.h"
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struct cbuf {
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unsigned int base;
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unsigned int len;
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unsigned int mask;
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};
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#define NODE_INCREMENT 32
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static void cbuf_add(struct cbuf *cb, int n)
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{
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cb->len += n;
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}
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static int cbuf_data(struct cbuf *cb)
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{
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return ((cb->base + cb->len) & cb->mask);
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}
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static void cbuf_init(struct cbuf *cb, int size)
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{
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cb->base = cb->len = 0;
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cb->mask = size-1;
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}
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static void cbuf_eat(struct cbuf *cb, int n)
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{
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cb->len -= n;
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cb->base += n;
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cb->base &= cb->mask;
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}
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static bool cbuf_empty(struct cbuf *cb)
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{
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return cb->len == 0;
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}
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/* Maximum number of incoming messages to process before
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doing a cond_resched()
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*/
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#define MAX_RX_MSG_COUNT 25
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struct connection {
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struct socket *sock; /* NULL if not connected */
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uint32_t nodeid; /* So we know who we are in the list */
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struct mutex sock_mutex;
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unsigned long flags; /* bit 1,2 = We are on the read/write lists */
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#define CF_READ_PENDING 1
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#define CF_WRITE_PENDING 2
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#define CF_CONNECT_PENDING 3
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#define CF_IS_OTHERCON 4
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struct list_head writequeue; /* List of outgoing writequeue_entries */
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struct list_head listenlist; /* List of allocated listening sockets */
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spinlock_t writequeue_lock;
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int (*rx_action) (struct connection *); /* What to do when active */
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struct page *rx_page;
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struct cbuf cb;
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int retries;
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#define MAX_CONNECT_RETRIES 3
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struct connection *othercon;
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struct work_struct rwork; /* Receive workqueue */
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struct work_struct swork; /* Send workqueue */
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};
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#define sock2con(x) ((struct connection *)(x)->sk_user_data)
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/* An entry waiting to be sent */
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struct writequeue_entry {
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struct list_head list;
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struct page *page;
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int offset;
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int len;
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int end;
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int users;
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struct connection *con;
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};
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static struct sockaddr_storage dlm_local_addr;
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/* Work queues */
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static struct workqueue_struct *recv_workqueue;
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static struct workqueue_struct *send_workqueue;
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/* An array of pointers to connections, indexed by NODEID */
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static struct connection **connections;
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static DECLARE_MUTEX(connections_lock);
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static struct kmem_cache *con_cache;
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static int conn_array_size;
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static void process_recv_sockets(struct work_struct *work);
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static void process_send_sockets(struct work_struct *work);
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static struct connection *nodeid2con(int nodeid, gfp_t allocation)
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{
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struct connection *con = NULL;
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down(&connections_lock);
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if (nodeid >= conn_array_size) {
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int new_size = nodeid + NODE_INCREMENT;
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struct connection **new_conns;
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new_conns = kzalloc(sizeof(struct connection *) *
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new_size, allocation);
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if (!new_conns)
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goto finish;
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memcpy(new_conns, connections, sizeof(struct connection *) * conn_array_size);
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conn_array_size = new_size;
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kfree(connections);
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connections = new_conns;
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}
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con = connections[nodeid];
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if (con == NULL && allocation) {
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con = kmem_cache_zalloc(con_cache, allocation);
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if (!con)
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goto finish;
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con->nodeid = nodeid;
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mutex_init(&con->sock_mutex);
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INIT_LIST_HEAD(&con->writequeue);
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spin_lock_init(&con->writequeue_lock);
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INIT_WORK(&con->swork, process_send_sockets);
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INIT_WORK(&con->rwork, process_recv_sockets);
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connections[nodeid] = con;
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}
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finish:
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up(&connections_lock);
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return con;
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}
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/* Data available on socket or listen socket received a connect */
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static void lowcomms_data_ready(struct sock *sk, int count_unused)
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{
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struct connection *con = sock2con(sk);
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if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
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queue_work(recv_workqueue, &con->rwork);
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}
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static void lowcomms_write_space(struct sock *sk)
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{
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struct connection *con = sock2con(sk);
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if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
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queue_work(send_workqueue, &con->swork);
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}
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static inline void lowcomms_connect_sock(struct connection *con)
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{
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if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
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queue_work(send_workqueue, &con->swork);
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}
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static void lowcomms_state_change(struct sock *sk)
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{
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if (sk->sk_state == TCP_ESTABLISHED)
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lowcomms_write_space(sk);
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}
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/* Make a socket active */
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static int add_sock(struct socket *sock, struct connection *con)
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{
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con->sock = sock;
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/* Install a data_ready callback */
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con->sock->sk->sk_data_ready = lowcomms_data_ready;
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con->sock->sk->sk_write_space = lowcomms_write_space;
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con->sock->sk->sk_state_change = lowcomms_state_change;
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return 0;
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}
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/* Add the port number to an IP6 or 4 sockaddr and return the address
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length */
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static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
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int *addr_len)
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{
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saddr->ss_family = dlm_local_addr.ss_family;
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if (saddr->ss_family == AF_INET) {
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struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
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in4_addr->sin_port = cpu_to_be16(port);
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*addr_len = sizeof(struct sockaddr_in);
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} else {
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struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
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in6_addr->sin6_port = cpu_to_be16(port);
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*addr_len = sizeof(struct sockaddr_in6);
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}
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}
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/* Close a remote connection and tidy up */
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static void close_connection(struct connection *con, bool and_other)
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{
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mutex_lock(&con->sock_mutex);
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if (con->sock) {
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sock_release(con->sock);
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con->sock = NULL;
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}
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if (con->othercon && and_other) {
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/* Will only re-enter once. */
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close_connection(con->othercon, false);
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}
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if (con->rx_page) {
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__free_page(con->rx_page);
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con->rx_page = NULL;
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}
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con->retries = 0;
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mutex_unlock(&con->sock_mutex);
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}
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/* Data received from remote end */
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static int receive_from_sock(struct connection *con)
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{
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int ret = 0;
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struct msghdr msg = {};
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struct kvec iov[2];
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unsigned len;
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int r;
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int call_again_soon = 0;
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int nvec;
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mutex_lock(&con->sock_mutex);
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if (con->sock == NULL) {
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ret = -EAGAIN;
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goto out_close;
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}
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if (con->rx_page == NULL) {
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/*
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* This doesn't need to be atomic, but I think it should
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* improve performance if it is.
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*/
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con->rx_page = alloc_page(GFP_ATOMIC);
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if (con->rx_page == NULL)
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goto out_resched;
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cbuf_init(&con->cb, PAGE_CACHE_SIZE);
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}
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/*
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* iov[0] is the bit of the circular buffer between the current end
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* point (cb.base + cb.len) and the end of the buffer.
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*/
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iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
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iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
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nvec = 1;
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/*
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* iov[1] is the bit of the circular buffer between the start of the
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* buffer and the start of the currently used section (cb.base)
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*/
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if (cbuf_data(&con->cb) >= con->cb.base) {
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iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);
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iov[1].iov_len = con->cb.base;
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iov[1].iov_base = page_address(con->rx_page);
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nvec = 2;
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}
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len = iov[0].iov_len + iov[1].iov_len;
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r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
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MSG_DONTWAIT | MSG_NOSIGNAL);
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if (ret <= 0)
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goto out_close;
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if (ret == -EAGAIN)
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goto out_resched;
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if (ret == len)
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call_again_soon = 1;
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cbuf_add(&con->cb, ret);
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ret = dlm_process_incoming_buffer(con->nodeid,
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page_address(con->rx_page),
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con->cb.base, con->cb.len,
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PAGE_CACHE_SIZE);
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if (ret == -EBADMSG) {
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printk(KERN_INFO "dlm: lowcomms: addr=%p, base=%u, len=%u, "
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"iov_len=%u, iov_base[0]=%p, read=%d\n",
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page_address(con->rx_page), con->cb.base, con->cb.len,
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len, iov[0].iov_base, r);
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}
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if (ret < 0)
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goto out_close;
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cbuf_eat(&con->cb, ret);
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if (cbuf_empty(&con->cb) && !call_again_soon) {
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__free_page(con->rx_page);
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con->rx_page = NULL;
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}
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if (call_again_soon)
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goto out_resched;
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mutex_unlock(&con->sock_mutex);
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return 0;
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out_resched:
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if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
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queue_work(recv_workqueue, &con->rwork);
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mutex_unlock(&con->sock_mutex);
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return -EAGAIN;
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out_close:
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mutex_unlock(&con->sock_mutex);
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if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) {
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close_connection(con, false);
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/* Reconnect when there is something to send */
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}
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/* Don't return success if we really got EOF */
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if (ret == 0)
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ret = -EAGAIN;
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return ret;
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}
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/* Listening socket is busy, accept a connection */
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static int accept_from_sock(struct connection *con)
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{
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int result;
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struct sockaddr_storage peeraddr;
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struct socket *newsock;
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int len;
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int nodeid;
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struct connection *newcon;
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struct connection *addcon;
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memset(&peeraddr, 0, sizeof(peeraddr));
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result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM,
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IPPROTO_TCP, &newsock);
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if (result < 0)
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return -ENOMEM;
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mutex_lock_nested(&con->sock_mutex, 0);
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result = -ENOTCONN;
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if (con->sock == NULL)
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goto accept_err;
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newsock->type = con->sock->type;
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newsock->ops = con->sock->ops;
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result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
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if (result < 0)
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goto accept_err;
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/* Get the connected socket's peer */
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memset(&peeraddr, 0, sizeof(peeraddr));
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if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
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&len, 2)) {
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result = -ECONNABORTED;
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goto accept_err;
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}
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/* Get the new node's NODEID */
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make_sockaddr(&peeraddr, 0, &len);
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if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
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printk("dlm: connect from non cluster node\n");
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sock_release(newsock);
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mutex_unlock(&con->sock_mutex);
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return -1;
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}
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log_print("got connection from %d", nodeid);
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/* Check to see if we already have a connection to this node. This
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* could happen if the two nodes initiate a connection at roughly
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* the same time and the connections cross on the wire.
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* TEMPORARY FIX:
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* In this case we store the incoming one in "othercon"
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*/
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newcon = nodeid2con(nodeid, GFP_KERNEL);
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if (!newcon) {
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result = -ENOMEM;
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goto accept_err;
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}
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mutex_lock_nested(&newcon->sock_mutex, 1);
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if (newcon->sock) {
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struct connection *othercon = newcon->othercon;
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if (!othercon) {
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othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL);
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if (!othercon) {
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printk("dlm: failed to allocate incoming socket\n");
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mutex_unlock(&newcon->sock_mutex);
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result = -ENOMEM;
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goto accept_err;
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}
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othercon->nodeid = nodeid;
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othercon->rx_action = receive_from_sock;
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mutex_init(&othercon->sock_mutex);
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INIT_WORK(&othercon->swork, process_send_sockets);
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INIT_WORK(&othercon->rwork, process_recv_sockets);
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set_bit(CF_IS_OTHERCON, &othercon->flags);
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newcon->othercon = othercon;
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}
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othercon->sock = newsock;
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newsock->sk->sk_user_data = othercon;
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add_sock(newsock, othercon);
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addcon = othercon;
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}
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else {
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newsock->sk->sk_user_data = newcon;
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newcon->rx_action = receive_from_sock;
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add_sock(newsock, newcon);
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addcon = newcon;
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}
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mutex_unlock(&newcon->sock_mutex);
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/*
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* Add it to the active queue in case we got data
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* beween processing the accept adding the socket
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* to the read_sockets list
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*/
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if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
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queue_work(recv_workqueue, &addcon->rwork);
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mutex_unlock(&con->sock_mutex);
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return 0;
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accept_err:
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mutex_unlock(&con->sock_mutex);
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sock_release(newsock);
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if (result != -EAGAIN)
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printk("dlm: error accepting connection from node: %d\n", result);
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return result;
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}
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/* Connect a new socket to its peer */
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static void connect_to_sock(struct connection *con)
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{
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int result = -EHOSTUNREACH;
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struct sockaddr_storage saddr;
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int addr_len;
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struct socket *sock;
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if (con->nodeid == 0) {
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log_print("attempt to connect sock 0 foiled");
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return;
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}
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mutex_lock(&con->sock_mutex);
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if (con->retries++ > MAX_CONNECT_RETRIES)
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goto out;
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/* Some odd races can cause double-connects, ignore them */
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if (con->sock) {
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result = 0;
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goto out;
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}
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/* Create a socket to communicate with */
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result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM,
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IPPROTO_TCP, &sock);
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if (result < 0)
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goto out_err;
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memset(&saddr, 0, sizeof(saddr));
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if (dlm_nodeid_to_addr(con->nodeid, &saddr))
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goto out_err;
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sock->sk->sk_user_data = con;
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con->rx_action = receive_from_sock;
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make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
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|
|
add_sock(sock, con);
|
|
|
|
log_print("connecting to %d", con->nodeid);
|
|
result =
|
|
sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
|
|
O_NONBLOCK);
|
|
if (result == -EINPROGRESS)
|
|
result = 0;
|
|
if (result == 0)
|
|
goto out;
|
|
|
|
out_err:
|
|
if (con->sock) {
|
|
sock_release(con->sock);
|
|
con->sock = NULL;
|
|
}
|
|
/*
|
|
* 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) {
|
|
lowcomms_connect_sock(con);
|
|
result = 0;
|
|
}
|
|
out:
|
|
mutex_unlock(&con->sock_mutex);
|
|
return;
|
|
}
|
|
|
|
static struct socket *create_listen_sock(struct connection *con,
|
|
struct sockaddr_storage *saddr)
|
|
{
|
|
struct socket *sock = NULL;
|
|
mm_segment_t fs;
|
|
int result = 0;
|
|
int one = 1;
|
|
int addr_len;
|
|
|
|
if (dlm_local_addr.ss_family == AF_INET)
|
|
addr_len = sizeof(struct sockaddr_in);
|
|
else
|
|
addr_len = sizeof(struct sockaddr_in6);
|
|
|
|
/* Create a socket to communicate with */
|
|
result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM, IPPROTO_TCP, &sock);
|
|
if (result < 0) {
|
|
printk("dlm: Can't create listening comms socket\n");
|
|
goto create_out;
|
|
}
|
|
|
|
fs = get_fs();
|
|
set_fs(get_ds());
|
|
result = sock_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
|
|
(char *)&one, sizeof(one));
|
|
set_fs(fs);
|
|
if (result < 0) {
|
|
printk("dlm: Failed to set SO_REUSEADDR on socket: result=%d\n",
|
|
result);
|
|
}
|
|
sock->sk->sk_user_data = con;
|
|
con->rx_action = accept_from_sock;
|
|
con->sock = sock;
|
|
|
|
/* Bind to our port */
|
|
make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
|
|
result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
|
|
if (result < 0) {
|
|
printk("dlm: Can't bind to port %d\n", dlm_config.ci_tcp_port);
|
|
sock_release(sock);
|
|
sock = NULL;
|
|
con->sock = NULL;
|
|
goto create_out;
|
|
}
|
|
|
|
fs = get_fs();
|
|
set_fs(get_ds());
|
|
|
|
result = sock_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
|
|
(char *)&one, sizeof(one));
|
|
set_fs(fs);
|
|
if (result < 0) {
|
|
printk("dlm: Set keepalive failed: %d\n", result);
|
|
}
|
|
|
|
result = sock->ops->listen(sock, 5);
|
|
if (result < 0) {
|
|
printk("dlm: Can't listen on port %d\n", dlm_config.ci_tcp_port);
|
|
sock_release(sock);
|
|
sock = NULL;
|
|
goto create_out;
|
|
}
|
|
|
|
create_out:
|
|
return sock;
|
|
}
|
|
|
|
|
|
/* Listen on all interfaces */
|
|
static int listen_for_all(void)
|
|
{
|
|
struct socket *sock = NULL;
|
|
struct connection *con = nodeid2con(0, GFP_KERNEL);
|
|
int result = -EINVAL;
|
|
|
|
/* We don't support multi-homed hosts */
|
|
set_bit(CF_IS_OTHERCON, &con->flags);
|
|
|
|
sock = create_listen_sock(con, &dlm_local_addr);
|
|
if (sock) {
|
|
add_sock(sock, con);
|
|
result = 0;
|
|
}
|
|
else {
|
|
result = -EADDRINUSE;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
|
|
static struct writequeue_entry *new_writequeue_entry(struct connection *con,
|
|
gfp_t allocation)
|
|
{
|
|
struct writequeue_entry *entry;
|
|
|
|
entry = kmalloc(sizeof(struct writequeue_entry), allocation);
|
|
if (!entry)
|
|
return NULL;
|
|
|
|
entry->page = alloc_page(allocation);
|
|
if (!entry->page) {
|
|
kfree(entry);
|
|
return NULL;
|
|
}
|
|
|
|
entry->offset = 0;
|
|
entry->len = 0;
|
|
entry->end = 0;
|
|
entry->users = 0;
|
|
entry->con = con;
|
|
|
|
return entry;
|
|
}
|
|
|
|
void *dlm_lowcomms_get_buffer(int nodeid, int len,
|
|
gfp_t allocation, char **ppc)
|
|
{
|
|
struct connection *con;
|
|
struct writequeue_entry *e;
|
|
int offset = 0;
|
|
int users = 0;
|
|
|
|
con = nodeid2con(nodeid, allocation);
|
|
if (!con)
|
|
return NULL;
|
|
|
|
spin_lock(&con->writequeue_lock);
|
|
e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
|
|
if ((&e->list == &con->writequeue) ||
|
|
(PAGE_CACHE_SIZE - e->end < len)) {
|
|
e = NULL;
|
|
} else {
|
|
offset = e->end;
|
|
e->end += len;
|
|
users = e->users++;
|
|
}
|
|
spin_unlock(&con->writequeue_lock);
|
|
|
|
if (e) {
|
|
got_one:
|
|
if (users == 0)
|
|
kmap(e->page);
|
|
*ppc = page_address(e->page) + offset;
|
|
return e;
|
|
}
|
|
|
|
e = new_writequeue_entry(con, allocation);
|
|
if (e) {
|
|
spin_lock(&con->writequeue_lock);
|
|
offset = e->end;
|
|
e->end += len;
|
|
users = e->users++;
|
|
list_add_tail(&e->list, &con->writequeue);
|
|
spin_unlock(&con->writequeue_lock);
|
|
goto got_one;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
void dlm_lowcomms_commit_buffer(void *mh)
|
|
{
|
|
struct writequeue_entry *e = (struct writequeue_entry *)mh;
|
|
struct connection *con = e->con;
|
|
int users;
|
|
|
|
spin_lock(&con->writequeue_lock);
|
|
users = --e->users;
|
|
if (users)
|
|
goto out;
|
|
e->len = e->end - e->offset;
|
|
kunmap(e->page);
|
|
spin_unlock(&con->writequeue_lock);
|
|
|
|
if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
|
|
queue_work(send_workqueue, &con->swork);
|
|
}
|
|
return;
|
|
|
|
out:
|
|
spin_unlock(&con->writequeue_lock);
|
|
return;
|
|
}
|
|
|
|
static void free_entry(struct writequeue_entry *e)
|
|
{
|
|
__free_page(e->page);
|
|
kfree(e);
|
|
}
|
|
|
|
/* Send a message */
|
|
static void send_to_sock(struct connection *con)
|
|
{
|
|
int ret = 0;
|
|
ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int);
|
|
const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
|
|
struct writequeue_entry *e;
|
|
int len, offset;
|
|
|
|
mutex_lock(&con->sock_mutex);
|
|
if (con->sock == NULL)
|
|
goto out_connect;
|
|
|
|
sendpage = con->sock->ops->sendpage;
|
|
|
|
spin_lock(&con->writequeue_lock);
|
|
for (;;) {
|
|
e = list_entry(con->writequeue.next, struct writequeue_entry,
|
|
list);
|
|
if ((struct list_head *) e == &con->writequeue)
|
|
break;
|
|
|
|
len = e->len;
|
|
offset = e->offset;
|
|
BUG_ON(len == 0 && e->users == 0);
|
|
spin_unlock(&con->writequeue_lock);
|
|
kmap(e->page);
|
|
|
|
ret = 0;
|
|
if (len) {
|
|
ret = sendpage(con->sock, e->page, offset, len,
|
|
msg_flags);
|
|
if (ret == -EAGAIN || ret == 0)
|
|
goto out;
|
|
if (ret <= 0)
|
|
goto send_error;
|
|
}
|
|
else {
|
|
/* Don't starve people filling buffers */
|
|
cond_resched();
|
|
}
|
|
|
|
spin_lock(&con->writequeue_lock);
|
|
e->offset += ret;
|
|
e->len -= ret;
|
|
|
|
if (e->len == 0 && e->users == 0) {
|
|
list_del(&e->list);
|
|
kunmap(e->page);
|
|
free_entry(e);
|
|
continue;
|
|
}
|
|
}
|
|
spin_unlock(&con->writequeue_lock);
|
|
out:
|
|
mutex_unlock(&con->sock_mutex);
|
|
return;
|
|
|
|
send_error:
|
|
mutex_unlock(&con->sock_mutex);
|
|
close_connection(con, false);
|
|
lowcomms_connect_sock(con);
|
|
return;
|
|
|
|
out_connect:
|
|
mutex_unlock(&con->sock_mutex);
|
|
connect_to_sock(con);
|
|
return;
|
|
}
|
|
|
|
static void clean_one_writequeue(struct connection *con)
|
|
{
|
|
struct list_head *list;
|
|
struct list_head *temp;
|
|
|
|
spin_lock(&con->writequeue_lock);
|
|
list_for_each_safe(list, temp, &con->writequeue) {
|
|
struct writequeue_entry *e =
|
|
list_entry(list, struct writequeue_entry, list);
|
|
list_del(&e->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;
|
|
|
|
if (!connections)
|
|
goto out;
|
|
|
|
log_print("closing connection to node %d", nodeid);
|
|
con = nodeid2con(nodeid, 0);
|
|
if (con) {
|
|
clean_one_writequeue(con);
|
|
close_connection(con, true);
|
|
}
|
|
return 0;
|
|
|
|
out:
|
|
return -1;
|
|
}
|
|
|
|
/* Look for activity on active sockets */
|
|
static void process_recv_sockets(struct work_struct *work)
|
|
{
|
|
struct connection *con = container_of(work, struct connection, rwork);
|
|
int err;
|
|
|
|
clear_bit(CF_READ_PENDING, &con->flags);
|
|
do {
|
|
err = con->rx_action(con);
|
|
} while (!err);
|
|
}
|
|
|
|
|
|
static void process_send_sockets(struct work_struct *work)
|
|
{
|
|
struct connection *con = container_of(work, struct connection, swork);
|
|
|
|
if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
|
|
connect_to_sock(con);
|
|
}
|
|
|
|
clear_bit(CF_WRITE_PENDING, &con->flags);
|
|
send_to_sock(con);
|
|
}
|
|
|
|
|
|
/* Discard all entries on the write queues */
|
|
static void clean_writequeues(void)
|
|
{
|
|
int nodeid;
|
|
|
|
for (nodeid = 1; nodeid < conn_array_size; nodeid++) {
|
|
struct connection *con = nodeid2con(nodeid, 0);
|
|
|
|
if (con)
|
|
clean_one_writequeue(con);
|
|
}
|
|
}
|
|
|
|
static void work_stop(void)
|
|
{
|
|
destroy_workqueue(recv_workqueue);
|
|
destroy_workqueue(send_workqueue);
|
|
}
|
|
|
|
static int work_start(void)
|
|
{
|
|
int error;
|
|
recv_workqueue = create_workqueue("dlm_recv");
|
|
error = IS_ERR(recv_workqueue);
|
|
if (error) {
|
|
log_print("can't start dlm_recv %d", error);
|
|
return error;
|
|
}
|
|
|
|
send_workqueue = create_singlethread_workqueue("dlm_send");
|
|
error = IS_ERR(send_workqueue);
|
|
if (error) {
|
|
log_print("can't start dlm_send %d", error);
|
|
destroy_workqueue(recv_workqueue);
|
|
return error;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void dlm_lowcomms_stop(void)
|
|
{
|
|
int i;
|
|
|
|
/* Set all the flags to prevent any
|
|
socket activity.
|
|
*/
|
|
for (i = 0; i < conn_array_size; i++) {
|
|
if (connections[i])
|
|
connections[i]->flags |= 0xFF;
|
|
}
|
|
|
|
work_stop();
|
|
clean_writequeues();
|
|
|
|
for (i = 0; i < conn_array_size; i++) {
|
|
if (connections[i]) {
|
|
close_connection(connections[i], true);
|
|
if (connections[i]->othercon)
|
|
kmem_cache_free(con_cache, connections[i]->othercon);
|
|
kmem_cache_free(con_cache, connections[i]);
|
|
}
|
|
}
|
|
|
|
kfree(connections);
|
|
connections = NULL;
|
|
|
|
kmem_cache_destroy(con_cache);
|
|
}
|
|
|
|
/* This is quite likely to sleep... */
|
|
int dlm_lowcomms_start(void)
|
|
{
|
|
int error = 0;
|
|
|
|
error = -ENOMEM;
|
|
connections = kzalloc(sizeof(struct connection *) *
|
|
NODE_INCREMENT, GFP_KERNEL);
|
|
if (!connections)
|
|
goto out;
|
|
|
|
conn_array_size = NODE_INCREMENT;
|
|
|
|
if (dlm_our_addr(&dlm_local_addr, 0)) {
|
|
log_print("no local IP address has been set");
|
|
goto fail_free_conn;
|
|
}
|
|
if (!dlm_our_addr(&dlm_local_addr, 1)) {
|
|
log_print("This dlm comms module does not support multi-homed clustering");
|
|
goto fail_free_conn;
|
|
}
|
|
|
|
con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
|
|
__alignof__(struct connection), 0,
|
|
NULL, NULL);
|
|
if (!con_cache)
|
|
goto fail_free_conn;
|
|
|
|
|
|
/* Start listening */
|
|
error = listen_for_all();
|
|
if (error)
|
|
goto fail_unlisten;
|
|
|
|
error = work_start();
|
|
if (error)
|
|
goto fail_unlisten;
|
|
|
|
return 0;
|
|
|
|
fail_unlisten:
|
|
close_connection(connections[0], false);
|
|
kmem_cache_free(con_cache, connections[0]);
|
|
kmem_cache_destroy(con_cache);
|
|
|
|
fail_free_conn:
|
|
kfree(connections);
|
|
|
|
out:
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Overrides for Emacs so that we follow Linus's tabbing style.
|
|
* Emacs will notice this stuff at the end of the file and automatically
|
|
* adjust the settings for this buffer only. This must remain at the end
|
|
* of the file.
|
|
* ---------------------------------------------------------------------------
|
|
* Local variables:
|
|
* c-file-style: "linux"
|
|
* End:
|
|
*/
|