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![Alexander Aring](/assets/img/avatar_default.png)
During my code inspection I saw there is no implementation of a graceful shutdown for tcp. This patch will introduce a graceful shutdown for tcp connections. The shutdown is implemented synchronized as dlm_lowcomms_stop() is called to end all dlm communication. After shutdown is done, a lot of flush and closing functionality will be called. However I don't see a problem with that. The waitqueue for synchronize the shutdown has a timeout of 10 seconds, if timeout a force close will be exectued. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
1735 lines
42 KiB
C
1735 lines
42 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/******************************************************************************
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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) 2004-2009 Red Hat, Inc. All rights reserved.
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**
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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 its
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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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* lowcomms will choose to use either TCP or SCTP as its transport layer
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* depending on the configuration variable 'protocol'. This should be set
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* to 0 (default) for TCP or 1 for SCTP. It should be configured using a
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* cluster-wide mechanism as it must be the same on all nodes of the cluster
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* for the DLM to function.
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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 <linux/file.h>
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#include <linux/mutex.h>
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#include <linux/sctp.h>
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#include <linux/slab.h>
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#include <net/sctp/sctp.h>
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#include <net/ipv6.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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#define NEEDED_RMEM (4*1024*1024)
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#define CONN_HASH_SIZE 32
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/* Number of messages to send before rescheduling */
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#define MAX_SEND_MSG_COUNT 25
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#define DLM_SHUTDOWN_WAIT_TIMEOUT msecs_to_jiffies(10000)
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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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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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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;
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#define CF_READ_PENDING 1
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#define CF_WRITE_PENDING 2
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#define CF_INIT_PENDING 4
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#define CF_IS_OTHERCON 5
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#define CF_CLOSE 6
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#define CF_APP_LIMITED 7
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#define CF_CLOSING 8
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#define CF_SHUTDOWN 9
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struct list_head writequeue; /* List of outgoing writequeue_entries */
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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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void (*connect_action) (struct connection *); /* What to do to connect */
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void (*shutdown_action)(struct connection *con); /* What to do to shutdown */
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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 hlist_node list;
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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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wait_queue_head_t shutdown_wait; /* wait for graceful shutdown */
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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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struct dlm_node_addr {
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struct list_head list;
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int nodeid;
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int addr_count;
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int curr_addr_index;
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struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
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};
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static struct listen_sock_callbacks {
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void (*sk_error_report)(struct sock *);
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void (*sk_data_ready)(struct sock *);
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void (*sk_state_change)(struct sock *);
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void (*sk_write_space)(struct sock *);
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} listen_sock;
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static LIST_HEAD(dlm_node_addrs);
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static DEFINE_SPINLOCK(dlm_node_addrs_spin);
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static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
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static int dlm_local_count;
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static int dlm_allow_conn;
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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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static struct hlist_head connection_hash[CONN_HASH_SIZE];
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static DEFINE_MUTEX(connections_lock);
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static struct kmem_cache *con_cache;
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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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/* This is deliberately very simple because most clusters have simple
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sequential nodeids, so we should be able to go straight to a connection
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struct in the array */
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static inline int nodeid_hash(int nodeid)
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{
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return nodeid & (CONN_HASH_SIZE-1);
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}
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static struct connection *__find_con(int nodeid)
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{
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int r;
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struct connection *con;
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r = nodeid_hash(nodeid);
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hlist_for_each_entry(con, &connection_hash[r], list) {
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if (con->nodeid == nodeid)
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return con;
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}
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return NULL;
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}
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/*
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* If 'allocation' is zero then we don't attempt to create a new
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* connection structure for this node.
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*/
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static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
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{
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struct connection *con = NULL;
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int r;
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con = __find_con(nodeid);
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if (con || !alloc)
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return con;
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con = kmem_cache_zalloc(con_cache, alloc);
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if (!con)
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return NULL;
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r = nodeid_hash(nodeid);
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hlist_add_head(&con->list, &connection_hash[r]);
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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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init_waitqueue_head(&con->shutdown_wait);
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/* Setup action pointers for child sockets */
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if (con->nodeid) {
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struct connection *zerocon = __find_con(0);
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con->connect_action = zerocon->connect_action;
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if (!con->rx_action)
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con->rx_action = zerocon->rx_action;
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}
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return con;
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}
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/* Loop round all connections */
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static void foreach_conn(void (*conn_func)(struct connection *c))
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{
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int i;
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struct hlist_node *n;
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struct connection *con;
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for (i = 0; i < CONN_HASH_SIZE; i++) {
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hlist_for_each_entry_safe(con, n, &connection_hash[i], list)
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conn_func(con);
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}
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}
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static struct connection *nodeid2con(int nodeid, gfp_t allocation)
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{
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struct connection *con;
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mutex_lock(&connections_lock);
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con = __nodeid2con(nodeid, allocation);
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mutex_unlock(&connections_lock);
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return con;
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}
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static struct dlm_node_addr *find_node_addr(int nodeid)
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{
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struct dlm_node_addr *na;
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list_for_each_entry(na, &dlm_node_addrs, list) {
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if (na->nodeid == nodeid)
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return na;
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}
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return NULL;
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}
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static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y)
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{
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switch (x->ss_family) {
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case AF_INET: {
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struct sockaddr_in *sinx = (struct sockaddr_in *)x;
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struct sockaddr_in *siny = (struct sockaddr_in *)y;
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if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr)
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return 0;
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if (sinx->sin_port != siny->sin_port)
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return 0;
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break;
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}
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case AF_INET6: {
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struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x;
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struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y;
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if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr))
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return 0;
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if (sinx->sin6_port != siny->sin6_port)
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return 0;
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break;
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}
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default:
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return 0;
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}
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return 1;
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}
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static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out,
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struct sockaddr *sa_out, bool try_new_addr)
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{
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struct sockaddr_storage sas;
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struct dlm_node_addr *na;
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if (!dlm_local_count)
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return -1;
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spin_lock(&dlm_node_addrs_spin);
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na = find_node_addr(nodeid);
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if (na && na->addr_count) {
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memcpy(&sas, na->addr[na->curr_addr_index],
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sizeof(struct sockaddr_storage));
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if (try_new_addr) {
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na->curr_addr_index++;
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if (na->curr_addr_index == na->addr_count)
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na->curr_addr_index = 0;
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}
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}
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spin_unlock(&dlm_node_addrs_spin);
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if (!na)
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return -EEXIST;
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if (!na->addr_count)
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return -ENOENT;
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if (sas_out)
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memcpy(sas_out, &sas, sizeof(struct sockaddr_storage));
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if (!sa_out)
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return 0;
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if (dlm_local_addr[0]->ss_family == AF_INET) {
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struct sockaddr_in *in4 = (struct sockaddr_in *) &sas;
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struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out;
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ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
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} else {
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struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas;
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struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out;
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ret6->sin6_addr = in6->sin6_addr;
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}
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return 0;
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}
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static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid)
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{
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struct dlm_node_addr *na;
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int rv = -EEXIST;
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int addr_i;
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spin_lock(&dlm_node_addrs_spin);
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list_for_each_entry(na, &dlm_node_addrs, list) {
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if (!na->addr_count)
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continue;
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for (addr_i = 0; addr_i < na->addr_count; addr_i++) {
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if (addr_compare(na->addr[addr_i], addr)) {
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*nodeid = na->nodeid;
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rv = 0;
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goto unlock;
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}
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}
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}
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unlock:
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spin_unlock(&dlm_node_addrs_spin);
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return rv;
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}
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int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len)
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{
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struct sockaddr_storage *new_addr;
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struct dlm_node_addr *new_node, *na;
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new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS);
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if (!new_node)
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return -ENOMEM;
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new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS);
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if (!new_addr) {
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kfree(new_node);
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return -ENOMEM;
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}
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memcpy(new_addr, addr, len);
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spin_lock(&dlm_node_addrs_spin);
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na = find_node_addr(nodeid);
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if (!na) {
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new_node->nodeid = nodeid;
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new_node->addr[0] = new_addr;
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new_node->addr_count = 1;
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list_add(&new_node->list, &dlm_node_addrs);
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spin_unlock(&dlm_node_addrs_spin);
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return 0;
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}
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if (na->addr_count >= DLM_MAX_ADDR_COUNT) {
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spin_unlock(&dlm_node_addrs_spin);
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kfree(new_addr);
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kfree(new_node);
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return -ENOSPC;
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}
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na->addr[na->addr_count++] = new_addr;
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spin_unlock(&dlm_node_addrs_spin);
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kfree(new_node);
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return 0;
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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)
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{
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struct connection *con;
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read_lock_bh(&sk->sk_callback_lock);
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con = sock2con(sk);
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if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags))
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queue_work(recv_workqueue, &con->rwork);
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read_unlock_bh(&sk->sk_callback_lock);
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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;
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read_lock_bh(&sk->sk_callback_lock);
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con = sock2con(sk);
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if (!con)
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goto out;
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clear_bit(SOCK_NOSPACE, &con->sock->flags);
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if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) {
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con->sock->sk->sk_write_pending--;
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clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags);
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}
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queue_work(send_workqueue, &con->swork);
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out:
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read_unlock_bh(&sk->sk_callback_lock);
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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_bit(CF_CLOSE, &con->flags))
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return;
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queue_work(send_workqueue, &con->swork);
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cond_resched();
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}
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static void lowcomms_state_change(struct sock *sk)
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{
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/* SCTP layer is not calling sk_data_ready when the connection
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* is done, so we catch the signal through here. Also, it
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* doesn't switch socket state when entering shutdown, so we
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* skip the write in that case.
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*/
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if (sk->sk_shutdown) {
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if (sk->sk_shutdown == RCV_SHUTDOWN)
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lowcomms_data_ready(sk);
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} else if (sk->sk_state == TCP_ESTABLISHED) {
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lowcomms_write_space(sk);
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}
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}
|
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|
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int dlm_lowcomms_connect_node(int nodeid)
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{
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struct connection *con;
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|
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if (nodeid == dlm_our_nodeid())
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return 0;
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con = nodeid2con(nodeid, GFP_NOFS);
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if (!con)
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return -ENOMEM;
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lowcomms_connect_sock(con);
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return 0;
|
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}
|
|
|
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static void lowcomms_error_report(struct sock *sk)
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{
|
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struct connection *con;
|
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struct sockaddr_storage saddr;
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void (*orig_report)(struct sock *) = NULL;
|
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|
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read_lock_bh(&sk->sk_callback_lock);
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con = sock2con(sk);
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if (con == NULL)
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goto out;
|
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orig_report = listen_sock.sk_error_report;
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if (con->sock == NULL ||
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kernel_getpeername(con->sock, (struct sockaddr *)&saddr) < 0) {
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printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
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|
"sending to node %d, port %d, "
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|
"sk_err=%d/%d\n", dlm_our_nodeid(),
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con->nodeid, dlm_config.ci_tcp_port,
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sk->sk_err, sk->sk_err_soft);
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} else if (saddr.ss_family == AF_INET) {
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struct sockaddr_in *sin4 = (struct sockaddr_in *)&saddr;
|
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|
|
printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
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|
"sending to node %d at %pI4, port %d, "
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|
"sk_err=%d/%d\n", dlm_our_nodeid(),
|
|
con->nodeid, &sin4->sin_addr.s_addr,
|
|
dlm_config.ci_tcp_port, sk->sk_err,
|
|
sk->sk_err_soft);
|
|
} else {
|
|
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&saddr;
|
|
|
|
printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
|
|
"sending to node %d at %u.%u.%u.%u, "
|
|
"port %d, sk_err=%d/%d\n", dlm_our_nodeid(),
|
|
con->nodeid, sin6->sin6_addr.s6_addr32[0],
|
|
sin6->sin6_addr.s6_addr32[1],
|
|
sin6->sin6_addr.s6_addr32[2],
|
|
sin6->sin6_addr.s6_addr32[3],
|
|
dlm_config.ci_tcp_port, sk->sk_err,
|
|
sk->sk_err_soft);
|
|
}
|
|
out:
|
|
read_unlock_bh(&sk->sk_callback_lock);
|
|
if (orig_report)
|
|
orig_report(sk);
|
|
}
|
|
|
|
/* Note: sk_callback_lock must be locked before calling this function. */
|
|
static void save_listen_callbacks(struct socket *sock)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
|
|
listen_sock.sk_data_ready = sk->sk_data_ready;
|
|
listen_sock.sk_state_change = sk->sk_state_change;
|
|
listen_sock.sk_write_space = sk->sk_write_space;
|
|
listen_sock.sk_error_report = sk->sk_error_report;
|
|
}
|
|
|
|
static void restore_callbacks(struct socket *sock)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
|
|
write_lock_bh(&sk->sk_callback_lock);
|
|
sk->sk_user_data = NULL;
|
|
sk->sk_data_ready = listen_sock.sk_data_ready;
|
|
sk->sk_state_change = listen_sock.sk_state_change;
|
|
sk->sk_write_space = listen_sock.sk_write_space;
|
|
sk->sk_error_report = listen_sock.sk_error_report;
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
}
|
|
|
|
/* Make a socket active */
|
|
static void add_sock(struct socket *sock, struct connection *con)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
|
|
write_lock_bh(&sk->sk_callback_lock);
|
|
con->sock = sock;
|
|
|
|
sk->sk_user_data = con;
|
|
/* Install a data_ready callback */
|
|
sk->sk_data_ready = lowcomms_data_ready;
|
|
sk->sk_write_space = lowcomms_write_space;
|
|
sk->sk_state_change = lowcomms_state_change;
|
|
sk->sk_allocation = GFP_NOFS;
|
|
sk->sk_error_report = lowcomms_error_report;
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
}
|
|
|
|
/* Add the port number to an IPv6 or 4 sockaddr and return the address
|
|
length */
|
|
static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
|
|
int *addr_len)
|
|
{
|
|
saddr->ss_family = dlm_local_addr[0]->ss_family;
|
|
if (saddr->ss_family == AF_INET) {
|
|
struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
|
|
in4_addr->sin_port = cpu_to_be16(port);
|
|
*addr_len = sizeof(struct sockaddr_in);
|
|
memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
|
|
} else {
|
|
struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
|
|
in6_addr->sin6_port = cpu_to_be16(port);
|
|
*addr_len = sizeof(struct sockaddr_in6);
|
|
}
|
|
memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
|
|
}
|
|
|
|
/* Close a remote connection and tidy up */
|
|
static void close_connection(struct connection *con, bool and_other,
|
|
bool tx, bool rx)
|
|
{
|
|
bool closing = test_and_set_bit(CF_CLOSING, &con->flags);
|
|
|
|
if (tx && !closing && cancel_work_sync(&con->swork)) {
|
|
log_print("canceled swork for node %d", con->nodeid);
|
|
clear_bit(CF_WRITE_PENDING, &con->flags);
|
|
}
|
|
if (rx && !closing && cancel_work_sync(&con->rwork)) {
|
|
log_print("canceled rwork for node %d", con->nodeid);
|
|
clear_bit(CF_READ_PENDING, &con->flags);
|
|
}
|
|
|
|
mutex_lock(&con->sock_mutex);
|
|
if (con->sock) {
|
|
restore_callbacks(con->sock);
|
|
sock_release(con->sock);
|
|
con->sock = NULL;
|
|
}
|
|
if (con->othercon && and_other) {
|
|
/* Will only re-enter once. */
|
|
close_connection(con->othercon, false, true, true);
|
|
}
|
|
if (con->rx_page) {
|
|
__free_page(con->rx_page);
|
|
con->rx_page = NULL;
|
|
}
|
|
|
|
con->retries = 0;
|
|
mutex_unlock(&con->sock_mutex);
|
|
clear_bit(CF_CLOSING, &con->flags);
|
|
}
|
|
|
|
static void shutdown_connection(struct connection *con)
|
|
{
|
|
int ret;
|
|
|
|
if (cancel_work_sync(&con->swork)) {
|
|
log_print("canceled swork for node %d", con->nodeid);
|
|
clear_bit(CF_WRITE_PENDING, &con->flags);
|
|
}
|
|
|
|
mutex_lock(&con->sock_mutex);
|
|
/* nothing to shutdown */
|
|
if (!con->sock) {
|
|
mutex_unlock(&con->sock_mutex);
|
|
return;
|
|
}
|
|
|
|
set_bit(CF_SHUTDOWN, &con->flags);
|
|
ret = kernel_sock_shutdown(con->sock, SHUT_WR);
|
|
mutex_unlock(&con->sock_mutex);
|
|
if (ret) {
|
|
log_print("Connection %p failed to shutdown: %d will force close",
|
|
con, ret);
|
|
goto force_close;
|
|
} else {
|
|
ret = wait_event_timeout(con->shutdown_wait,
|
|
!test_bit(CF_SHUTDOWN, &con->flags),
|
|
DLM_SHUTDOWN_WAIT_TIMEOUT);
|
|
if (ret == 0) {
|
|
log_print("Connection %p shutdown timed out, will force close",
|
|
con);
|
|
goto force_close;
|
|
}
|
|
}
|
|
|
|
return;
|
|
|
|
force_close:
|
|
clear_bit(CF_SHUTDOWN, &con->flags);
|
|
close_connection(con, false, true, true);
|
|
}
|
|
|
|
static void dlm_tcp_shutdown(struct connection *con)
|
|
{
|
|
if (con->othercon)
|
|
shutdown_connection(con->othercon);
|
|
shutdown_connection(con);
|
|
}
|
|
|
|
/* Data received from remote end */
|
|
static int receive_from_sock(struct connection *con)
|
|
{
|
|
int ret = 0;
|
|
struct msghdr msg = {};
|
|
struct kvec iov[2];
|
|
unsigned len;
|
|
int r;
|
|
int call_again_soon = 0;
|
|
int nvec;
|
|
|
|
mutex_lock(&con->sock_mutex);
|
|
|
|
if (con->sock == NULL) {
|
|
ret = -EAGAIN;
|
|
goto out_close;
|
|
}
|
|
if (con->nodeid == 0) {
|
|
ret = -EINVAL;
|
|
goto out_close;
|
|
}
|
|
|
|
if (con->rx_page == NULL) {
|
|
/*
|
|
* This doesn't need to be atomic, but I think it should
|
|
* improve performance if it is.
|
|
*/
|
|
con->rx_page = alloc_page(GFP_ATOMIC);
|
|
if (con->rx_page == NULL)
|
|
goto out_resched;
|
|
cbuf_init(&con->cb, PAGE_SIZE);
|
|
}
|
|
|
|
/*
|
|
* iov[0] is the bit of the circular buffer between the current end
|
|
* point (cb.base + cb.len) and the end of the buffer.
|
|
*/
|
|
iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
|
|
iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
|
|
iov[1].iov_len = 0;
|
|
nvec = 1;
|
|
|
|
/*
|
|
* iov[1] is the bit of the circular buffer between the start of the
|
|
* buffer and the start of the currently used section (cb.base)
|
|
*/
|
|
if (cbuf_data(&con->cb) >= con->cb.base) {
|
|
iov[0].iov_len = PAGE_SIZE - cbuf_data(&con->cb);
|
|
iov[1].iov_len = con->cb.base;
|
|
iov[1].iov_base = page_address(con->rx_page);
|
|
nvec = 2;
|
|
}
|
|
len = iov[0].iov_len + iov[1].iov_len;
|
|
iov_iter_kvec(&msg.msg_iter, READ, iov, nvec, len);
|
|
|
|
r = ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
|
|
if (ret <= 0)
|
|
goto out_close;
|
|
else if (ret == len)
|
|
call_again_soon = 1;
|
|
|
|
cbuf_add(&con->cb, ret);
|
|
ret = dlm_process_incoming_buffer(con->nodeid,
|
|
page_address(con->rx_page),
|
|
con->cb.base, con->cb.len,
|
|
PAGE_SIZE);
|
|
if (ret < 0) {
|
|
log_print("lowcomms err %d: addr=%p, base=%u, len=%u, read=%d",
|
|
ret, page_address(con->rx_page), con->cb.base,
|
|
con->cb.len, r);
|
|
cbuf_eat(&con->cb, r);
|
|
} else {
|
|
cbuf_eat(&con->cb, ret);
|
|
}
|
|
|
|
if (cbuf_empty(&con->cb) && !call_again_soon) {
|
|
__free_page(con->rx_page);
|
|
con->rx_page = NULL;
|
|
}
|
|
|
|
if (call_again_soon)
|
|
goto out_resched;
|
|
mutex_unlock(&con->sock_mutex);
|
|
return 0;
|
|
|
|
out_resched:
|
|
if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
|
|
queue_work(recv_workqueue, &con->rwork);
|
|
mutex_unlock(&con->sock_mutex);
|
|
return -EAGAIN;
|
|
|
|
out_close:
|
|
mutex_unlock(&con->sock_mutex);
|
|
if (ret != -EAGAIN) {
|
|
/* Reconnect when there is something to send */
|
|
close_connection(con, false, true, false);
|
|
if (ret == 0) {
|
|
log_print("connection %p got EOF from %d",
|
|
con, con->nodeid);
|
|
/* handling for tcp shutdown */
|
|
clear_bit(CF_SHUTDOWN, &con->flags);
|
|
wake_up(&con->shutdown_wait);
|
|
/* signal to breaking receive worker */
|
|
ret = -1;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Listening socket is busy, accept a connection */
|
|
static int accept_from_sock(struct connection *con)
|
|
{
|
|
int result;
|
|
struct sockaddr_storage peeraddr;
|
|
struct socket *newsock;
|
|
int len;
|
|
int nodeid;
|
|
struct connection *newcon;
|
|
struct connection *addcon;
|
|
|
|
mutex_lock(&connections_lock);
|
|
if (!dlm_allow_conn) {
|
|
mutex_unlock(&connections_lock);
|
|
return -1;
|
|
}
|
|
mutex_unlock(&connections_lock);
|
|
|
|
mutex_lock_nested(&con->sock_mutex, 0);
|
|
|
|
if (!con->sock) {
|
|
mutex_unlock(&con->sock_mutex);
|
|
return -ENOTCONN;
|
|
}
|
|
|
|
result = kernel_accept(con->sock, &newsock, O_NONBLOCK);
|
|
if (result < 0)
|
|
goto accept_err;
|
|
|
|
/* Get the connected socket's peer */
|
|
memset(&peeraddr, 0, sizeof(peeraddr));
|
|
len = newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 2);
|
|
if (len < 0) {
|
|
result = -ECONNABORTED;
|
|
goto accept_err;
|
|
}
|
|
|
|
/* Get the new node's NODEID */
|
|
make_sockaddr(&peeraddr, 0, &len);
|
|
if (addr_to_nodeid(&peeraddr, &nodeid)) {
|
|
unsigned char *b=(unsigned char *)&peeraddr;
|
|
log_print("connect from non cluster node");
|
|
print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE,
|
|
b, sizeof(struct sockaddr_storage));
|
|
sock_release(newsock);
|
|
mutex_unlock(&con->sock_mutex);
|
|
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"
|
|
*/
|
|
newcon = nodeid2con(nodeid, GFP_NOFS);
|
|
if (!newcon) {
|
|
result = -ENOMEM;
|
|
goto accept_err;
|
|
}
|
|
mutex_lock_nested(&newcon->sock_mutex, 1);
|
|
if (newcon->sock) {
|
|
struct connection *othercon = newcon->othercon;
|
|
|
|
if (!othercon) {
|
|
othercon = kmem_cache_zalloc(con_cache, GFP_NOFS);
|
|
if (!othercon) {
|
|
log_print("failed to allocate incoming socket");
|
|
mutex_unlock(&newcon->sock_mutex);
|
|
result = -ENOMEM;
|
|
goto accept_err;
|
|
}
|
|
othercon->nodeid = nodeid;
|
|
othercon->rx_action = receive_from_sock;
|
|
mutex_init(&othercon->sock_mutex);
|
|
INIT_LIST_HEAD(&othercon->writequeue);
|
|
spin_lock_init(&othercon->writequeue_lock);
|
|
INIT_WORK(&othercon->swork, process_send_sockets);
|
|
INIT_WORK(&othercon->rwork, process_recv_sockets);
|
|
init_waitqueue_head(&othercon->shutdown_wait);
|
|
set_bit(CF_IS_OTHERCON, &othercon->flags);
|
|
} else {
|
|
/* close other sock con if we have something new */
|
|
close_connection(othercon, false, true, false);
|
|
}
|
|
|
|
mutex_lock_nested(&othercon->sock_mutex, 2);
|
|
newcon->othercon = othercon;
|
|
add_sock(newsock, othercon);
|
|
addcon = othercon;
|
|
mutex_unlock(&othercon->sock_mutex);
|
|
}
|
|
else {
|
|
newcon->rx_action = receive_from_sock;
|
|
/* accept copies the sk after we've saved the callbacks, so we
|
|
don't want to save them a second time or comm errors will
|
|
result in calling sk_error_report recursively. */
|
|
add_sock(newsock, newcon);
|
|
addcon = newcon;
|
|
}
|
|
|
|
mutex_unlock(&newcon->sock_mutex);
|
|
|
|
/*
|
|
* Add it to the active queue in case we got data
|
|
* between processing the accept adding the socket
|
|
* to the read_sockets list
|
|
*/
|
|
if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
|
|
queue_work(recv_workqueue, &addcon->rwork);
|
|
mutex_unlock(&con->sock_mutex);
|
|
|
|
return 0;
|
|
|
|
accept_err:
|
|
mutex_unlock(&con->sock_mutex);
|
|
if (newsock)
|
|
sock_release(newsock);
|
|
|
|
if (result != -EAGAIN)
|
|
log_print("error accepting connection from node: %d", result);
|
|
return result;
|
|
}
|
|
|
|
static void free_entry(struct writequeue_entry *e)
|
|
{
|
|
__free_page(e->page);
|
|
kfree(e);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
if (e->len == 0 && e->users == 0) {
|
|
list_del(&e->list);
|
|
free_entry(e);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* sctp_bind_addrs - bind a SCTP socket to all our addresses
|
|
*/
|
|
static int sctp_bind_addrs(struct connection *con, 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(con->sock, addr, addr_len);
|
|
else
|
|
result = sock_bind_add(con->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;
|
|
}
|
|
|
|
/* Initiate an SCTP association.
|
|
This is a special case of send_to_sock() in that we don't yet have a
|
|
peeled-off socket for this association, so we use the listening socket
|
|
and add the primary IP address of the remote node.
|
|
*/
|
|
static void sctp_connect_to_sock(struct connection *con)
|
|
{
|
|
struct sockaddr_storage daddr;
|
|
int result;
|
|
int addr_len;
|
|
struct socket *sock;
|
|
unsigned int mark;
|
|
|
|
if (con->nodeid == 0) {
|
|
log_print("attempt to connect sock 0 foiled");
|
|
return;
|
|
}
|
|
|
|
mutex_lock(&con->sock_mutex);
|
|
|
|
/* Some odd races can cause double-connects, ignore them */
|
|
if (con->retries++ > MAX_CONNECT_RETRIES)
|
|
goto out;
|
|
|
|
if (con->sock) {
|
|
log_print("node %d already connected.", con->nodeid);
|
|
goto out;
|
|
}
|
|
|
|
memset(&daddr, 0, sizeof(daddr));
|
|
result = nodeid_to_addr(con->nodeid, &daddr, NULL, true);
|
|
if (result < 0) {
|
|
log_print("no address for nodeid %d", con->nodeid);
|
|
goto out;
|
|
}
|
|
|
|
/* Create a socket to communicate with */
|
|
result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
|
|
SOCK_STREAM, IPPROTO_SCTP, &sock);
|
|
if (result < 0)
|
|
goto socket_err;
|
|
|
|
/* set skb mark */
|
|
result = dlm_comm_mark(con->nodeid, &mark);
|
|
if (result < 0)
|
|
goto bind_err;
|
|
|
|
sock_set_mark(sock->sk, mark);
|
|
|
|
con->rx_action = receive_from_sock;
|
|
con->connect_action = sctp_connect_to_sock;
|
|
add_sock(sock, con);
|
|
|
|
/* Bind to all addresses. */
|
|
if (sctp_bind_addrs(con, 0))
|
|
goto bind_err;
|
|
|
|
make_sockaddr(&daddr, dlm_config.ci_tcp_port, &addr_len);
|
|
|
|
log_print("connecting to %d", con->nodeid);
|
|
|
|
/* Turn off Nagle's algorithm */
|
|
sctp_sock_set_nodelay(sock->sk);
|
|
|
|
/*
|
|
* 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);
|
|
result = sock->ops->connect(sock, (struct sockaddr *)&daddr, addr_len,
|
|
0);
|
|
sock_set_sndtimeo(sock->sk, 0);
|
|
|
|
if (result == -EINPROGRESS)
|
|
result = 0;
|
|
if (result == 0)
|
|
goto out;
|
|
|
|
bind_err:
|
|
con->sock = NULL;
|
|
sock_release(sock);
|
|
|
|
socket_err:
|
|
/*
|
|
* Some errors are fatal and this list might need adjusting. For other
|
|
* errors we try again until the max number of retries is reached.
|
|
*/
|
|
if (result != -EHOSTUNREACH &&
|
|
result != -ENETUNREACH &&
|
|
result != -ENETDOWN &&
|
|
result != -EINVAL &&
|
|
result != -EPROTONOSUPPORT) {
|
|
log_print("connect %d try %d error %d", con->nodeid,
|
|
con->retries, result);
|
|
mutex_unlock(&con->sock_mutex);
|
|
msleep(1000);
|
|
lowcomms_connect_sock(con);
|
|
return;
|
|
}
|
|
|
|
out:
|
|
mutex_unlock(&con->sock_mutex);
|
|
}
|
|
|
|
/* Connect a new socket to its peer */
|
|
static void tcp_connect_to_sock(struct connection *con)
|
|
{
|
|
struct sockaddr_storage saddr, src_addr;
|
|
int addr_len;
|
|
struct socket *sock = NULL;
|
|
unsigned int mark;
|
|
int result;
|
|
|
|
if (con->nodeid == 0) {
|
|
log_print("attempt to connect sock 0 foiled");
|
|
return;
|
|
}
|
|
|
|
mutex_lock(&con->sock_mutex);
|
|
if (con->retries++ > MAX_CONNECT_RETRIES)
|
|
goto out;
|
|
|
|
/* Some odd races can cause double-connects, ignore them */
|
|
if (con->sock)
|
|
goto out;
|
|
|
|
/* Create a socket to communicate with */
|
|
result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
|
|
SOCK_STREAM, IPPROTO_TCP, &sock);
|
|
if (result < 0)
|
|
goto out_err;
|
|
|
|
/* set skb mark */
|
|
result = dlm_comm_mark(con->nodeid, &mark);
|
|
if (result < 0)
|
|
goto out_err;
|
|
|
|
sock_set_mark(sock->sk, mark);
|
|
|
|
memset(&saddr, 0, sizeof(saddr));
|
|
result = nodeid_to_addr(con->nodeid, &saddr, NULL, false);
|
|
if (result < 0) {
|
|
log_print("no address for nodeid %d", con->nodeid);
|
|
goto out_err;
|
|
}
|
|
|
|
con->rx_action = receive_from_sock;
|
|
con->connect_action = tcp_connect_to_sock;
|
|
con->shutdown_action = dlm_tcp_shutdown;
|
|
add_sock(sock, con);
|
|
|
|
/* 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) {
|
|
log_print("could not bind for connect: %d", result);
|
|
/* This *may* not indicate a critical error */
|
|
}
|
|
|
|
make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
|
|
|
|
log_print("connecting to %d", con->nodeid);
|
|
|
|
/* Turn off Nagle's algorithm */
|
|
tcp_sock_set_nodelay(sock->sk);
|
|
|
|
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;
|
|
} else if (sock) {
|
|
sock_release(sock);
|
|
}
|
|
/*
|
|
* Some errors are fatal and this list might need adjusting. For other
|
|
* errors we try again until the max number of retries is reached.
|
|
*/
|
|
if (result != -EHOSTUNREACH &&
|
|
result != -ENETUNREACH &&
|
|
result != -ENETDOWN &&
|
|
result != -EINVAL &&
|
|
result != -EPROTONOSUPPORT) {
|
|
log_print("connect %d try %d error %d", con->nodeid,
|
|
con->retries, result);
|
|
mutex_unlock(&con->sock_mutex);
|
|
msleep(1000);
|
|
lowcomms_connect_sock(con);
|
|
return;
|
|
}
|
|
out:
|
|
mutex_unlock(&con->sock_mutex);
|
|
return;
|
|
}
|
|
|
|
static struct socket *tcp_create_listen_sock(struct connection *con,
|
|
struct sockaddr_storage *saddr)
|
|
{
|
|
struct socket *sock = NULL;
|
|
int result = 0;
|
|
int addr_len;
|
|
|
|
if (dlm_local_addr[0]->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(&init_net, dlm_local_addr[0]->ss_family,
|
|
SOCK_STREAM, IPPROTO_TCP, &sock);
|
|
if (result < 0) {
|
|
log_print("Can't create listening comms socket");
|
|
goto create_out;
|
|
}
|
|
|
|
sock_set_mark(sock->sk, dlm_config.ci_mark);
|
|
|
|
/* Turn off Nagle's algorithm */
|
|
tcp_sock_set_nodelay(sock->sk);
|
|
|
|
sock_set_reuseaddr(sock->sk);
|
|
|
|
write_lock_bh(&sock->sk->sk_callback_lock);
|
|
sock->sk->sk_user_data = con;
|
|
save_listen_callbacks(sock);
|
|
con->rx_action = accept_from_sock;
|
|
con->connect_action = tcp_connect_to_sock;
|
|
write_unlock_bh(&sock->sk->sk_callback_lock);
|
|
|
|
/* 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) {
|
|
log_print("Can't bind to port %d", dlm_config.ci_tcp_port);
|
|
sock_release(sock);
|
|
sock = NULL;
|
|
con->sock = NULL;
|
|
goto create_out;
|
|
}
|
|
sock_set_keepalive(sock->sk);
|
|
|
|
result = sock->ops->listen(sock, 5);
|
|
if (result < 0) {
|
|
log_print("Can't listen on port %d", dlm_config.ci_tcp_port);
|
|
sock_release(sock);
|
|
sock = NULL;
|
|
goto create_out;
|
|
}
|
|
|
|
create_out:
|
|
return sock;
|
|
}
|
|
|
|
/* Get local addresses */
|
|
static void init_local(void)
|
|
{
|
|
struct sockaddr_storage sas, *addr;
|
|
int i;
|
|
|
|
dlm_local_count = 0;
|
|
for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) {
|
|
if (dlm_our_addr(&sas, i))
|
|
break;
|
|
|
|
addr = kmemdup(&sas, sizeof(*addr), GFP_NOFS);
|
|
if (!addr)
|
|
break;
|
|
dlm_local_addr[dlm_local_count++] = addr;
|
|
}
|
|
}
|
|
|
|
/* Initialise SCTP socket and bind to all interfaces */
|
|
static int sctp_listen_for_all(void)
|
|
{
|
|
struct socket *sock = NULL;
|
|
int result = -EINVAL;
|
|
struct connection *con = nodeid2con(0, GFP_NOFS);
|
|
|
|
if (!con)
|
|
return -ENOMEM;
|
|
|
|
log_print("Using SCTP for communications");
|
|
|
|
result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
|
|
SOCK_STREAM, IPPROTO_SCTP, &sock);
|
|
if (result < 0) {
|
|
log_print("Can't create comms socket, check SCTP is loaded");
|
|
goto out;
|
|
}
|
|
|
|
sock_set_rcvbuf(sock->sk, NEEDED_RMEM);
|
|
sock_set_mark(sock->sk, dlm_config.ci_mark);
|
|
sctp_sock_set_nodelay(sock->sk);
|
|
|
|
write_lock_bh(&sock->sk->sk_callback_lock);
|
|
/* Init con struct */
|
|
sock->sk->sk_user_data = con;
|
|
save_listen_callbacks(sock);
|
|
con->sock = sock;
|
|
con->sock->sk->sk_data_ready = lowcomms_data_ready;
|
|
con->rx_action = accept_from_sock;
|
|
con->connect_action = sctp_connect_to_sock;
|
|
|
|
write_unlock_bh(&sock->sk->sk_callback_lock);
|
|
|
|
/* Bind to all addresses. */
|
|
if (sctp_bind_addrs(con, dlm_config.ci_tcp_port))
|
|
goto create_delsock;
|
|
|
|
result = sock->ops->listen(sock, 5);
|
|
if (result < 0) {
|
|
log_print("Can't set socket listening");
|
|
goto create_delsock;
|
|
}
|
|
|
|
return 0;
|
|
|
|
create_delsock:
|
|
sock_release(sock);
|
|
con->sock = NULL;
|
|
out:
|
|
return result;
|
|
}
|
|
|
|
static int tcp_listen_for_all(void)
|
|
{
|
|
struct socket *sock = NULL;
|
|
struct connection *con = nodeid2con(0, GFP_NOFS);
|
|
int result = -EINVAL;
|
|
|
|
if (!con)
|
|
return -ENOMEM;
|
|
|
|
/* We don't support multi-homed hosts */
|
|
if (dlm_local_addr[1] != NULL) {
|
|
log_print("TCP protocol can't handle multi-homed hosts, "
|
|
"try SCTP");
|
|
return -EINVAL;
|
|
}
|
|
|
|
log_print("Using TCP for communications");
|
|
|
|
sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
|
|
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;
|
|
|
|
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_SIZE - e->end < len)) {
|
|
e = NULL;
|
|
} else {
|
|
offset = e->end;
|
|
e->end += len;
|
|
e->users++;
|
|
}
|
|
spin_unlock(&con->writequeue_lock);
|
|
|
|
if (e) {
|
|
got_one:
|
|
*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;
|
|
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;
|
|
spin_unlock(&con->writequeue_lock);
|
|
|
|
queue_work(send_workqueue, &con->swork);
|
|
return;
|
|
|
|
out:
|
|
spin_unlock(&con->writequeue_lock);
|
|
return;
|
|
}
|
|
|
|
/* Send a message */
|
|
static void send_to_sock(struct connection *con)
|
|
{
|
|
int ret = 0;
|
|
const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
|
|
struct writequeue_entry *e;
|
|
int len, offset;
|
|
int count = 0;
|
|
|
|
mutex_lock(&con->sock_mutex);
|
|
if (con->sock == NULL)
|
|
goto out_connect;
|
|
|
|
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);
|
|
|
|
ret = 0;
|
|
if (len) {
|
|
ret = kernel_sendpage(con->sock, e->page, offset, len,
|
|
msg_flags);
|
|
if (ret == -EAGAIN || ret == 0) {
|
|
if (ret == -EAGAIN &&
|
|
test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) &&
|
|
!test_and_set_bit(CF_APP_LIMITED, &con->flags)) {
|
|
/* Notify TCP that we're limited by the
|
|
* application window size.
|
|
*/
|
|
set_bit(SOCK_NOSPACE, &con->sock->flags);
|
|
con->sock->sk->sk_write_pending++;
|
|
}
|
|
cond_resched();
|
|
goto out;
|
|
} else if (ret < 0)
|
|
goto send_error;
|
|
}
|
|
|
|
/* Don't starve people filling buffers */
|
|
if (++count >= MAX_SEND_MSG_COUNT) {
|
|
cond_resched();
|
|
count = 0;
|
|
}
|
|
|
|
spin_lock(&con->writequeue_lock);
|
|
writequeue_entry_complete(e, ret);
|
|
}
|
|
spin_unlock(&con->writequeue_lock);
|
|
out:
|
|
mutex_unlock(&con->sock_mutex);
|
|
return;
|
|
|
|
send_error:
|
|
mutex_unlock(&con->sock_mutex);
|
|
close_connection(con, false, false, true);
|
|
/* Requeue the send work. When the work daemon runs again, it will try
|
|
a new connection, then call this function again. */
|
|
queue_work(send_workqueue, &con->swork);
|
|
return;
|
|
|
|
out_connect:
|
|
mutex_unlock(&con->sock_mutex);
|
|
queue_work(send_workqueue, &con->swork);
|
|
cond_resched();
|
|
}
|
|
|
|
static void clean_one_writequeue(struct connection *con)
|
|
{
|
|
struct writequeue_entry *e, *safe;
|
|
|
|
spin_lock(&con->writequeue_lock);
|
|
list_for_each_entry_safe(e, safe, &con->writequeue, list) {
|
|
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;
|
|
struct dlm_node_addr *na;
|
|
|
|
log_print("closing connection to node %d", nodeid);
|
|
con = nodeid2con(nodeid, 0);
|
|
if (con) {
|
|
set_bit(CF_CLOSE, &con->flags);
|
|
close_connection(con, true, true, true);
|
|
clean_one_writequeue(con);
|
|
}
|
|
|
|
spin_lock(&dlm_node_addrs_spin);
|
|
na = find_node_addr(nodeid);
|
|
if (na) {
|
|
list_del(&na->list);
|
|
while (na->addr_count--)
|
|
kfree(na->addr[na->addr_count]);
|
|
kfree(na);
|
|
}
|
|
spin_unlock(&dlm_node_addrs_spin);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Receive workqueue function */
|
|
static void process_recv_sockets(struct work_struct *work)
|
|
{
|
|
struct connection *con = container_of(work, struct connection, rwork);
|
|
int err;
|
|
|
|
clear_bit(CF_READ_PENDING, &con->flags);
|
|
do {
|
|
err = con->rx_action(con);
|
|
} while (!err);
|
|
}
|
|
|
|
/* Send workqueue function */
|
|
static void process_send_sockets(struct work_struct *work)
|
|
{
|
|
struct connection *con = container_of(work, struct connection, swork);
|
|
|
|
clear_bit(CF_WRITE_PENDING, &con->flags);
|
|
if (con->sock == NULL) /* not mutex protected so check it inside too */
|
|
con->connect_action(con);
|
|
if (!list_empty(&con->writequeue))
|
|
send_to_sock(con);
|
|
}
|
|
|
|
|
|
/* Discard all entries on the write queues */
|
|
static void clean_writequeues(void)
|
|
{
|
|
foreach_conn(clean_one_writequeue);
|
|
}
|
|
|
|
static void work_stop(void)
|
|
{
|
|
if (recv_workqueue)
|
|
destroy_workqueue(recv_workqueue);
|
|
if (send_workqueue)
|
|
destroy_workqueue(send_workqueue);
|
|
}
|
|
|
|
static int work_start(void)
|
|
{
|
|
recv_workqueue = alloc_workqueue("dlm_recv",
|
|
WQ_UNBOUND | WQ_MEM_RECLAIM, 1);
|
|
if (!recv_workqueue) {
|
|
log_print("can't start dlm_recv");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
send_workqueue = alloc_workqueue("dlm_send",
|
|
WQ_UNBOUND | WQ_MEM_RECLAIM, 1);
|
|
if (!send_workqueue) {
|
|
log_print("can't start dlm_send");
|
|
destroy_workqueue(recv_workqueue);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void _stop_conn(struct connection *con, bool and_other)
|
|
{
|
|
mutex_lock(&con->sock_mutex);
|
|
set_bit(CF_CLOSE, &con->flags);
|
|
set_bit(CF_READ_PENDING, &con->flags);
|
|
set_bit(CF_WRITE_PENDING, &con->flags);
|
|
if (con->sock && con->sock->sk) {
|
|
write_lock_bh(&con->sock->sk->sk_callback_lock);
|
|
con->sock->sk->sk_user_data = NULL;
|
|
write_unlock_bh(&con->sock->sk->sk_callback_lock);
|
|
}
|
|
if (con->othercon && and_other)
|
|
_stop_conn(con->othercon, false);
|
|
mutex_unlock(&con->sock_mutex);
|
|
}
|
|
|
|
static void stop_conn(struct connection *con)
|
|
{
|
|
_stop_conn(con, true);
|
|
}
|
|
|
|
static void shutdown_conn(struct connection *con)
|
|
{
|
|
if (con->shutdown_action)
|
|
con->shutdown_action(con);
|
|
}
|
|
|
|
static void free_conn(struct connection *con)
|
|
{
|
|
close_connection(con, true, true, true);
|
|
if (con->othercon)
|
|
kmem_cache_free(con_cache, con->othercon);
|
|
hlist_del(&con->list);
|
|
kmem_cache_free(con_cache, con);
|
|
}
|
|
|
|
static void work_flush(void)
|
|
{
|
|
int ok;
|
|
int i;
|
|
struct hlist_node *n;
|
|
struct connection *con;
|
|
|
|
if (recv_workqueue)
|
|
flush_workqueue(recv_workqueue);
|
|
if (send_workqueue)
|
|
flush_workqueue(send_workqueue);
|
|
do {
|
|
ok = 1;
|
|
foreach_conn(stop_conn);
|
|
if (recv_workqueue)
|
|
flush_workqueue(recv_workqueue);
|
|
if (send_workqueue)
|
|
flush_workqueue(send_workqueue);
|
|
for (i = 0; i < CONN_HASH_SIZE && ok; i++) {
|
|
hlist_for_each_entry_safe(con, n,
|
|
&connection_hash[i], list) {
|
|
ok &= test_bit(CF_READ_PENDING, &con->flags);
|
|
ok &= test_bit(CF_WRITE_PENDING, &con->flags);
|
|
if (con->othercon) {
|
|
ok &= test_bit(CF_READ_PENDING,
|
|
&con->othercon->flags);
|
|
ok &= test_bit(CF_WRITE_PENDING,
|
|
&con->othercon->flags);
|
|
}
|
|
}
|
|
}
|
|
} while (!ok);
|
|
}
|
|
|
|
void dlm_lowcomms_stop(void)
|
|
{
|
|
/* Set all the flags to prevent any
|
|
socket activity.
|
|
*/
|
|
mutex_lock(&connections_lock);
|
|
dlm_allow_conn = 0;
|
|
mutex_unlock(&connections_lock);
|
|
foreach_conn(shutdown_conn);
|
|
work_flush();
|
|
clean_writequeues();
|
|
foreach_conn(free_conn);
|
|
work_stop();
|
|
|
|
kmem_cache_destroy(con_cache);
|
|
}
|
|
|
|
int dlm_lowcomms_start(void)
|
|
{
|
|
int error = -EINVAL;
|
|
struct connection *con;
|
|
int i;
|
|
|
|
for (i = 0; i < CONN_HASH_SIZE; i++)
|
|
INIT_HLIST_HEAD(&connection_hash[i]);
|
|
|
|
init_local();
|
|
if (!dlm_local_count) {
|
|
error = -ENOTCONN;
|
|
log_print("no local IP address has been set");
|
|
goto fail;
|
|
}
|
|
|
|
error = -ENOMEM;
|
|
con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
|
|
__alignof__(struct connection), 0,
|
|
NULL);
|
|
if (!con_cache)
|
|
goto fail;
|
|
|
|
error = work_start();
|
|
if (error)
|
|
goto fail_destroy;
|
|
|
|
dlm_allow_conn = 1;
|
|
|
|
/* Start listening */
|
|
if (dlm_config.ci_protocol == 0)
|
|
error = tcp_listen_for_all();
|
|
else
|
|
error = sctp_listen_for_all();
|
|
if (error)
|
|
goto fail_unlisten;
|
|
|
|
return 0;
|
|
|
|
fail_unlisten:
|
|
dlm_allow_conn = 0;
|
|
con = nodeid2con(0,0);
|
|
if (con) {
|
|
close_connection(con, false, true, true);
|
|
kmem_cache_free(con_cache, con);
|
|
}
|
|
fail_destroy:
|
|
kmem_cache_destroy(con_cache);
|
|
fail:
|
|
return error;
|
|
}
|
|
|
|
void dlm_lowcomms_exit(void)
|
|
{
|
|
struct dlm_node_addr *na, *safe;
|
|
|
|
spin_lock(&dlm_node_addrs_spin);
|
|
list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) {
|
|
list_del(&na->list);
|
|
while (na->addr_count--)
|
|
kfree(na->addr[na->addr_count]);
|
|
kfree(na);
|
|
}
|
|
spin_unlock(&dlm_node_addrs_spin);
|
|
}
|