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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/dlm/lowcomms.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/dlm/lowcomms.c')
-rw-r--r--fs/dlm/lowcomms.c2053
1 files changed, 2053 insertions, 0 deletions
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
new file mode 100644
index 000000000..72f34f96d
--- /dev/null
+++ b/fs/dlm/lowcomms.c
@@ -0,0 +1,2053 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
+**
+**
+*******************************************************************************
+******************************************************************************/
+
+/*
+ * lowcomms.c
+ *
+ * This is the "low-level" comms layer.
+ *
+ * It is responsible for sending/receiving messages
+ * from other nodes in the cluster.
+ *
+ * Cluster nodes are referred to by their nodeids. nodeids are
+ * simply 32 bit numbers to the locking module - if they need to
+ * be expanded for the cluster infrastructure then that is its
+ * responsibility. It is this layer's
+ * responsibility to resolve these into IP address or
+ * whatever it needs for inter-node communication.
+ *
+ * The comms level is two kernel threads that deal mainly with
+ * the receiving of messages from other nodes and passing them
+ * up to the mid-level comms layer (which understands the
+ * message format) for execution by the locking core, and
+ * a send thread which does all the setting up of connections
+ * to remote nodes and the sending of data. Threads are not allowed
+ * to send their own data because it may cause them to wait in times
+ * of high load. Also, this way, the sending thread can collect together
+ * messages bound for one node and send them in one block.
+ *
+ * lowcomms will choose to use either TCP or SCTP as its transport layer
+ * depending on the configuration variable 'protocol'. This should be set
+ * to 0 (default) for TCP or 1 for SCTP. It should be configured using a
+ * cluster-wide mechanism as it must be the same on all nodes of the cluster
+ * for the DLM to function.
+ *
+ */
+
+#include <asm/ioctls.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/mutex.h>
+#include <linux/sctp.h>
+#include <linux/slab.h>
+#include <net/sctp/sctp.h>
+#include <net/ipv6.h>
+
+#include <trace/events/dlm.h>
+
+#include "dlm_internal.h"
+#include "lowcomms.h"
+#include "midcomms.h"
+#include "memory.h"
+#include "config.h"
+
+#define NEEDED_RMEM (4*1024*1024)
+
+/* Number of messages to send before rescheduling */
+#define MAX_SEND_MSG_COUNT 25
+#define DLM_SHUTDOWN_WAIT_TIMEOUT msecs_to_jiffies(10000)
+
+struct connection {
+ struct socket *sock; /* NULL if not connected */
+ uint32_t nodeid; /* So we know who we are in the list */
+ struct mutex sock_mutex;
+ unsigned long flags;
+#define CF_READ_PENDING 1
+#define CF_WRITE_PENDING 2
+#define CF_INIT_PENDING 4
+#define CF_IS_OTHERCON 5
+#define CF_CLOSE 6
+#define CF_APP_LIMITED 7
+#define CF_CLOSING 8
+#define CF_SHUTDOWN 9
+#define CF_CONNECTED 10
+#define CF_RECONNECT 11
+#define CF_DELAY_CONNECT 12
+#define CF_EOF 13
+ struct list_head writequeue; /* List of outgoing writequeue_entries */
+ spinlock_t writequeue_lock;
+ atomic_t writequeue_cnt;
+ int retries;
+#define MAX_CONNECT_RETRIES 3
+ struct hlist_node list;
+ struct connection *othercon;
+ struct connection *sendcon;
+ struct work_struct rwork; /* Receive workqueue */
+ struct work_struct swork; /* Send workqueue */
+ wait_queue_head_t shutdown_wait; /* wait for graceful shutdown */
+ unsigned char *rx_buf;
+ int rx_buflen;
+ int rx_leftover;
+ struct rcu_head rcu;
+};
+#define sock2con(x) ((struct connection *)(x)->sk_user_data)
+
+struct listen_connection {
+ struct socket *sock;
+ struct work_struct rwork;
+};
+
+#define DLM_WQ_REMAIN_BYTES(e) (PAGE_SIZE - e->end)
+#define DLM_WQ_LENGTH_BYTES(e) (e->end - e->offset)
+
+/* An entry waiting to be sent */
+struct writequeue_entry {
+ struct list_head list;
+ struct page *page;
+ int offset;
+ int len;
+ int end;
+ int users;
+ bool dirty;
+ struct connection *con;
+ struct list_head msgs;
+ struct kref ref;
+};
+
+struct dlm_msg {
+ struct writequeue_entry *entry;
+ struct dlm_msg *orig_msg;
+ bool retransmit;
+ void *ppc;
+ int len;
+ int idx; /* new()/commit() idx exchange */
+
+ struct list_head list;
+ struct kref ref;
+};
+
+struct dlm_node_addr {
+ struct list_head list;
+ int nodeid;
+ int mark;
+ int addr_count;
+ int curr_addr_index;
+ struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
+};
+
+struct dlm_proto_ops {
+ bool try_new_addr;
+ const char *name;
+ int proto;
+
+ int (*connect)(struct connection *con, struct socket *sock,
+ struct sockaddr *addr, int addr_len);
+ void (*sockopts)(struct socket *sock);
+ int (*bind)(struct socket *sock);
+ int (*listen_validate)(void);
+ void (*listen_sockopts)(struct socket *sock);
+ int (*listen_bind)(struct socket *sock);
+ /* What to do to shutdown */
+ void (*shutdown_action)(struct connection *con);
+ /* What to do to eof check */
+ bool (*eof_condition)(struct connection *con);
+};
+
+static struct listen_sock_callbacks {
+ void (*sk_error_report)(struct sock *);
+ void (*sk_data_ready)(struct sock *);
+ void (*sk_state_change)(struct sock *);
+ void (*sk_write_space)(struct sock *);
+} listen_sock;
+
+static LIST_HEAD(dlm_node_addrs);
+static DEFINE_SPINLOCK(dlm_node_addrs_spin);
+
+static struct listen_connection listen_con;
+static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
+static int dlm_local_count;
+int dlm_allow_conn;
+
+/* Work queues */
+static struct workqueue_struct *recv_workqueue;
+static struct workqueue_struct *send_workqueue;
+
+static struct hlist_head connection_hash[CONN_HASH_SIZE];
+static DEFINE_SPINLOCK(connections_lock);
+DEFINE_STATIC_SRCU(connections_srcu);
+
+static const struct dlm_proto_ops *dlm_proto_ops;
+
+static void process_recv_sockets(struct work_struct *work);
+static void process_send_sockets(struct work_struct *work);
+
+static void writequeue_entry_ctor(void *data)
+{
+ struct writequeue_entry *entry = data;
+
+ INIT_LIST_HEAD(&entry->msgs);
+}
+
+struct kmem_cache *dlm_lowcomms_writequeue_cache_create(void)
+{
+ return kmem_cache_create("dlm_writequeue", sizeof(struct writequeue_entry),
+ 0, 0, writequeue_entry_ctor);
+}
+
+struct kmem_cache *dlm_lowcomms_msg_cache_create(void)
+{
+ return kmem_cache_create("dlm_msg", sizeof(struct dlm_msg), 0, 0, NULL);
+}
+
+/* need to held writequeue_lock */
+static struct writequeue_entry *con_next_wq(struct connection *con)
+{
+ struct writequeue_entry *e;
+
+ if (list_empty(&con->writequeue))
+ return NULL;
+
+ e = list_first_entry(&con->writequeue, struct writequeue_entry,
+ list);
+ /* if len is zero nothing is to send, if there are users filling
+ * buffers we wait until the users are done so we can send more.
+ */
+ if (e->users || e->len == 0)
+ return NULL;
+
+ return e;
+}
+
+static struct connection *__find_con(int nodeid, int r)
+{
+ struct connection *con;
+
+ hlist_for_each_entry_rcu(con, &connection_hash[r], list) {
+ if (con->nodeid == nodeid)
+ return con;
+ }
+
+ return NULL;
+}
+
+static bool tcp_eof_condition(struct connection *con)
+{
+ return atomic_read(&con->writequeue_cnt);
+}
+
+static int dlm_con_init(struct connection *con, int nodeid)
+{
+ con->rx_buflen = dlm_config.ci_buffer_size;
+ con->rx_buf = kmalloc(con->rx_buflen, GFP_NOFS);
+ if (!con->rx_buf)
+ return -ENOMEM;
+
+ con->nodeid = nodeid;
+ mutex_init(&con->sock_mutex);
+ INIT_LIST_HEAD(&con->writequeue);
+ spin_lock_init(&con->writequeue_lock);
+ atomic_set(&con->writequeue_cnt, 0);
+ INIT_WORK(&con->swork, process_send_sockets);
+ INIT_WORK(&con->rwork, process_recv_sockets);
+ init_waitqueue_head(&con->shutdown_wait);
+
+ return 0;
+}
+
+/*
+ * If 'allocation' is zero then we don't attempt to create a new
+ * connection structure for this node.
+ */
+static struct connection *nodeid2con(int nodeid, gfp_t alloc)
+{
+ struct connection *con, *tmp;
+ int r, ret;
+
+ r = nodeid_hash(nodeid);
+ con = __find_con(nodeid, r);
+ if (con || !alloc)
+ return con;
+
+ con = kzalloc(sizeof(*con), alloc);
+ if (!con)
+ return NULL;
+
+ ret = dlm_con_init(con, nodeid);
+ if (ret) {
+ kfree(con);
+ return NULL;
+ }
+
+ spin_lock(&connections_lock);
+ /* Because multiple workqueues/threads calls this function it can
+ * race on multiple cpu's. Instead of locking hot path __find_con()
+ * we just check in rare cases of recently added nodes again
+ * under protection of connections_lock. If this is the case we
+ * abort our connection creation and return the existing connection.
+ */
+ tmp = __find_con(nodeid, r);
+ if (tmp) {
+ spin_unlock(&connections_lock);
+ kfree(con->rx_buf);
+ kfree(con);
+ return tmp;
+ }
+
+ hlist_add_head_rcu(&con->list, &connection_hash[r]);
+ spin_unlock(&connections_lock);
+
+ return con;
+}
+
+/* Loop round all connections */
+static void foreach_conn(void (*conn_func)(struct connection *c))
+{
+ int i;
+ struct connection *con;
+
+ for (i = 0; i < CONN_HASH_SIZE; i++) {
+ hlist_for_each_entry_rcu(con, &connection_hash[i], list)
+ conn_func(con);
+ }
+}
+
+static struct dlm_node_addr *find_node_addr(int nodeid)
+{
+ struct dlm_node_addr *na;
+
+ list_for_each_entry(na, &dlm_node_addrs, list) {
+ if (na->nodeid == nodeid)
+ return na;
+ }
+ return NULL;
+}
+
+static int addr_compare(const struct sockaddr_storage *x,
+ const struct sockaddr_storage *y)
+{
+ switch (x->ss_family) {
+ case AF_INET: {
+ struct sockaddr_in *sinx = (struct sockaddr_in *)x;
+ struct sockaddr_in *siny = (struct sockaddr_in *)y;
+ if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr)
+ return 0;
+ if (sinx->sin_port != siny->sin_port)
+ return 0;
+ break;
+ }
+ case AF_INET6: {
+ struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x;
+ struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y;
+ if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr))
+ return 0;
+ if (sinx->sin6_port != siny->sin6_port)
+ return 0;
+ break;
+ }
+ default:
+ return 0;
+ }
+ return 1;
+}
+
+static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out,
+ struct sockaddr *sa_out, bool try_new_addr,
+ unsigned int *mark)
+{
+ struct sockaddr_storage sas;
+ struct dlm_node_addr *na;
+
+ if (!dlm_local_count)
+ return -1;
+
+ spin_lock(&dlm_node_addrs_spin);
+ na = find_node_addr(nodeid);
+ if (na && na->addr_count) {
+ memcpy(&sas, na->addr[na->curr_addr_index],
+ sizeof(struct sockaddr_storage));
+
+ if (try_new_addr) {
+ na->curr_addr_index++;
+ if (na->curr_addr_index == na->addr_count)
+ na->curr_addr_index = 0;
+ }
+ }
+ spin_unlock(&dlm_node_addrs_spin);
+
+ if (!na)
+ return -EEXIST;
+
+ if (!na->addr_count)
+ return -ENOENT;
+
+ *mark = na->mark;
+
+ if (sas_out)
+ memcpy(sas_out, &sas, sizeof(struct sockaddr_storage));
+
+ if (!sa_out)
+ return 0;
+
+ if (dlm_local_addr[0]->ss_family == AF_INET) {
+ struct sockaddr_in *in4 = (struct sockaddr_in *) &sas;
+ struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out;
+ ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
+ } else {
+ struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas;
+ struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out;
+ ret6->sin6_addr = in6->sin6_addr;
+ }
+
+ return 0;
+}
+
+static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid,
+ unsigned int *mark)
+{
+ struct dlm_node_addr *na;
+ int rv = -EEXIST;
+ int addr_i;
+
+ spin_lock(&dlm_node_addrs_spin);
+ list_for_each_entry(na, &dlm_node_addrs, list) {
+ if (!na->addr_count)
+ continue;
+
+ for (addr_i = 0; addr_i < na->addr_count; addr_i++) {
+ if (addr_compare(na->addr[addr_i], addr)) {
+ *nodeid = na->nodeid;
+ *mark = na->mark;
+ rv = 0;
+ goto unlock;
+ }
+ }
+ }
+unlock:
+ spin_unlock(&dlm_node_addrs_spin);
+ return rv;
+}
+
+/* caller need to held dlm_node_addrs_spin lock */
+static bool dlm_lowcomms_na_has_addr(const struct dlm_node_addr *na,
+ const struct sockaddr_storage *addr)
+{
+ int i;
+
+ for (i = 0; i < na->addr_count; i++) {
+ if (addr_compare(na->addr[i], addr))
+ return true;
+ }
+
+ return false;
+}
+
+int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len)
+{
+ struct sockaddr_storage *new_addr;
+ struct dlm_node_addr *new_node, *na;
+ bool ret;
+
+ new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS);
+ if (!new_node)
+ return -ENOMEM;
+
+ new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS);
+ if (!new_addr) {
+ kfree(new_node);
+ return -ENOMEM;
+ }
+
+ memcpy(new_addr, addr, len);
+
+ spin_lock(&dlm_node_addrs_spin);
+ na = find_node_addr(nodeid);
+ if (!na) {
+ new_node->nodeid = nodeid;
+ new_node->addr[0] = new_addr;
+ new_node->addr_count = 1;
+ new_node->mark = dlm_config.ci_mark;
+ list_add(&new_node->list, &dlm_node_addrs);
+ spin_unlock(&dlm_node_addrs_spin);
+ return 0;
+ }
+
+ ret = dlm_lowcomms_na_has_addr(na, addr);
+ if (ret) {
+ spin_unlock(&dlm_node_addrs_spin);
+ kfree(new_addr);
+ kfree(new_node);
+ return -EEXIST;
+ }
+
+ if (na->addr_count >= DLM_MAX_ADDR_COUNT) {
+ spin_unlock(&dlm_node_addrs_spin);
+ kfree(new_addr);
+ kfree(new_node);
+ return -ENOSPC;
+ }
+
+ na->addr[na->addr_count++] = new_addr;
+ spin_unlock(&dlm_node_addrs_spin);
+ kfree(new_node);
+ return 0;
+}
+
+/* Data available on socket or listen socket received a connect */
+static void lowcomms_data_ready(struct sock *sk)
+{
+ struct connection *con;
+
+ con = sock2con(sk);
+ if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags))
+ queue_work(recv_workqueue, &con->rwork);
+}
+
+static void lowcomms_listen_data_ready(struct sock *sk)
+{
+ if (!dlm_allow_conn)
+ return;
+
+ queue_work(recv_workqueue, &listen_con.rwork);
+}
+
+static void lowcomms_write_space(struct sock *sk)
+{
+ struct connection *con;
+
+ con = sock2con(sk);
+ if (!con)
+ return;
+
+ if (!test_and_set_bit(CF_CONNECTED, &con->flags)) {
+ log_print("connected to node %d", con->nodeid);
+ queue_work(send_workqueue, &con->swork);
+ return;
+ }
+
+ clear_bit(SOCK_NOSPACE, &con->sock->flags);
+
+ if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) {
+ con->sock->sk->sk_write_pending--;
+ clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags);
+ }
+
+ queue_work(send_workqueue, &con->swork);
+}
+
+static inline void lowcomms_connect_sock(struct connection *con)
+{
+ if (test_bit(CF_CLOSE, &con->flags))
+ return;
+ queue_work(send_workqueue, &con->swork);
+ cond_resched();
+}
+
+static void lowcomms_state_change(struct sock *sk)
+{
+ /* SCTP layer is not calling sk_data_ready when the connection
+ * is done, so we catch the signal through here. Also, it
+ * doesn't switch socket state when entering shutdown, so we
+ * skip the write in that case.
+ */
+ if (sk->sk_shutdown) {
+ if (sk->sk_shutdown == RCV_SHUTDOWN)
+ lowcomms_data_ready(sk);
+ } else if (sk->sk_state == TCP_ESTABLISHED) {
+ lowcomms_write_space(sk);
+ }
+}
+
+int dlm_lowcomms_connect_node(int nodeid)
+{
+ struct connection *con;
+ int idx;
+
+ if (nodeid == dlm_our_nodeid())
+ return 0;
+
+ idx = srcu_read_lock(&connections_srcu);
+ con = nodeid2con(nodeid, GFP_NOFS);
+ if (!con) {
+ srcu_read_unlock(&connections_srcu, idx);
+ return -ENOMEM;
+ }
+
+ lowcomms_connect_sock(con);
+ srcu_read_unlock(&connections_srcu, idx);
+
+ return 0;
+}
+
+int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark)
+{
+ struct dlm_node_addr *na;
+
+ spin_lock(&dlm_node_addrs_spin);
+ na = find_node_addr(nodeid);
+ if (!na) {
+ spin_unlock(&dlm_node_addrs_spin);
+ return -ENOENT;
+ }
+
+ na->mark = mark;
+ spin_unlock(&dlm_node_addrs_spin);
+
+ return 0;
+}
+
+static void lowcomms_error_report(struct sock *sk)
+{
+ struct connection *con;
+ void (*orig_report)(struct sock *) = NULL;
+ struct inet_sock *inet;
+
+ con = sock2con(sk);
+ if (con == NULL)
+ goto out;
+
+ orig_report = listen_sock.sk_error_report;
+
+ inet = inet_sk(sk);
+ switch (sk->sk_family) {
+ case AF_INET:
+ printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
+ "sending to node %d at %pI4, dport %d, "
+ "sk_err=%d/%d\n", dlm_our_nodeid(),
+ con->nodeid, &inet->inet_daddr,
+ ntohs(inet->inet_dport), sk->sk_err,
+ sk->sk_err_soft);
+ break;
+#if IS_ENABLED(CONFIG_IPV6)
+ case AF_INET6:
+ printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
+ "sending to node %d at %pI6c, "
+ "dport %d, sk_err=%d/%d\n", dlm_our_nodeid(),
+ con->nodeid, &sk->sk_v6_daddr,
+ ntohs(inet->inet_dport), sk->sk_err,
+ sk->sk_err_soft);
+ break;
+#endif
+ default:
+ printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
+ "invalid socket family %d set, "
+ "sk_err=%d/%d\n", dlm_our_nodeid(),
+ sk->sk_family, sk->sk_err, sk->sk_err_soft);
+ goto out;
+ }
+
+ /* below sendcon only handling */
+ if (test_bit(CF_IS_OTHERCON, &con->flags))
+ con = con->sendcon;
+
+ switch (sk->sk_err) {
+ case ECONNREFUSED:
+ set_bit(CF_DELAY_CONNECT, &con->flags);
+ break;
+ default:
+ break;
+ }
+
+ if (!test_and_set_bit(CF_RECONNECT, &con->flags))
+ queue_work(send_workqueue, &con->swork);
+
+out:
+ 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;
+
+ lock_sock(sk);
+ 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;
+ release_sock(sk);
+}
+
+static void add_listen_sock(struct socket *sock, struct listen_connection *con)
+{
+ struct sock *sk = sock->sk;
+
+ lock_sock(sk);
+ save_listen_callbacks(sock);
+ con->sock = sock;
+
+ sk->sk_user_data = con;
+ sk->sk_allocation = GFP_NOFS;
+ /* Install a data_ready callback */
+ sk->sk_data_ready = lowcomms_listen_data_ready;
+ release_sock(sk);
+}
+
+/* Make a socket active */
+static void add_sock(struct socket *sock, struct connection *con)
+{
+ struct sock *sk = sock->sk;
+
+ lock_sock(sk);
+ con->sock = sock;
+
+ sk->sk_user_data = con;
+ /* 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;
+ release_sock(sk);
+}
+
+/* Add the port number to an IPv6 or 4 sockaddr and return the address
+ length */
+static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
+ int *addr_len)
+{
+ saddr->ss_family = dlm_local_addr[0]->ss_family;
+ if (saddr->ss_family == AF_INET) {
+ struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
+ in4_addr->sin_port = cpu_to_be16(port);
+ *addr_len = sizeof(struct sockaddr_in);
+ memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
+ } else {
+ struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
+ in6_addr->sin6_port = cpu_to_be16(port);
+ *addr_len = sizeof(struct sockaddr_in6);
+ }
+ memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
+}
+
+static void dlm_page_release(struct kref *kref)
+{
+ struct writequeue_entry *e = container_of(kref, struct writequeue_entry,
+ ref);
+
+ __free_page(e->page);
+ dlm_free_writequeue(e);
+}
+
+static void dlm_msg_release(struct kref *kref)
+{
+ struct dlm_msg *msg = container_of(kref, struct dlm_msg, ref);
+
+ kref_put(&msg->entry->ref, dlm_page_release);
+ dlm_free_msg(msg);
+}
+
+static void free_entry(struct writequeue_entry *e)
+{
+ struct dlm_msg *msg, *tmp;
+
+ list_for_each_entry_safe(msg, tmp, &e->msgs, list) {
+ if (msg->orig_msg) {
+ msg->orig_msg->retransmit = false;
+ kref_put(&msg->orig_msg->ref, dlm_msg_release);
+ }
+
+ list_del(&msg->list);
+ kref_put(&msg->ref, dlm_msg_release);
+ }
+
+ list_del(&e->list);
+ atomic_dec(&e->con->writequeue_cnt);
+ kref_put(&e->ref, dlm_page_release);
+}
+
+static void dlm_close_sock(struct socket **sock)
+{
+ if (*sock) {
+ restore_callbacks(*sock);
+ sock_release(*sock);
+ *sock = NULL;
+ }
+}
+
+/* Close a remote connection and tidy up */
+static void close_connection(struct connection *con, bool and_other,
+ bool tx, bool rx)
+{
+ bool closing = test_and_set_bit(CF_CLOSING, &con->flags);
+ struct writequeue_entry *e;
+
+ if (tx && !closing && cancel_work_sync(&con->swork)) {
+ log_print("canceled swork for node %d", con->nodeid);
+ clear_bit(CF_WRITE_PENDING, &con->flags);
+ }
+ if (rx && !closing && cancel_work_sync(&con->rwork)) {
+ log_print("canceled rwork for node %d", con->nodeid);
+ clear_bit(CF_READ_PENDING, &con->flags);
+ }
+
+ mutex_lock(&con->sock_mutex);
+ dlm_close_sock(&con->sock);
+
+ if (con->othercon && and_other) {
+ /* Will only re-enter once. */
+ close_connection(con->othercon, false, tx, rx);
+ }
+
+ /* if we send a writequeue entry only a half way, we drop the
+ * whole entry because reconnection and that we not start of the
+ * middle of a msg which will confuse the other end.
+ *
+ * we can always drop messages because retransmits, but what we
+ * cannot allow is to transmit half messages which may be processed
+ * at the other side.
+ *
+ * our policy is to start on a clean state when disconnects, we don't
+ * know what's send/received on transport layer in this case.
+ */
+ spin_lock(&con->writequeue_lock);
+ if (!list_empty(&con->writequeue)) {
+ e = list_first_entry(&con->writequeue, struct writequeue_entry,
+ list);
+ if (e->dirty)
+ free_entry(e);
+ }
+ spin_unlock(&con->writequeue_lock);
+
+ con->rx_leftover = 0;
+ con->retries = 0;
+ clear_bit(CF_APP_LIMITED, &con->flags);
+ clear_bit(CF_CONNECTED, &con->flags);
+ clear_bit(CF_DELAY_CONNECT, &con->flags);
+ clear_bit(CF_RECONNECT, &con->flags);
+ clear_bit(CF_EOF, &con->flags);
+ mutex_unlock(&con->sock_mutex);
+ clear_bit(CF_CLOSING, &con->flags);
+}
+
+static void shutdown_connection(struct connection *con)
+{
+ int ret;
+
+ flush_work(&con->swork);
+
+ mutex_lock(&con->sock_mutex);
+ /* nothing to shutdown */
+ if (!con->sock) {
+ mutex_unlock(&con->sock_mutex);
+ return;
+ }
+
+ set_bit(CF_SHUTDOWN, &con->flags);
+ ret = kernel_sock_shutdown(con->sock, SHUT_WR);
+ mutex_unlock(&con->sock_mutex);
+ if (ret) {
+ log_print("Connection %p failed to shutdown: %d will force close",
+ con, ret);
+ goto force_close;
+ } else {
+ ret = wait_event_timeout(con->shutdown_wait,
+ !test_bit(CF_SHUTDOWN, &con->flags),
+ DLM_SHUTDOWN_WAIT_TIMEOUT);
+ if (ret == 0) {
+ log_print("Connection %p shutdown timed out, will force close",
+ con);
+ goto force_close;
+ }
+ }
+
+ return;
+
+force_close:
+ clear_bit(CF_SHUTDOWN, &con->flags);
+ close_connection(con, false, true, true);
+}
+
+static void dlm_tcp_shutdown(struct connection *con)
+{
+ if (con->othercon)
+ shutdown_connection(con->othercon);
+ shutdown_connection(con);
+}
+
+static int con_realloc_receive_buf(struct connection *con, int newlen)
+{
+ unsigned char *newbuf;
+
+ newbuf = kmalloc(newlen, GFP_NOFS);
+ if (!newbuf)
+ return -ENOMEM;
+
+ /* copy any leftover from last receive */
+ if (con->rx_leftover)
+ memmove(newbuf, con->rx_buf, con->rx_leftover);
+
+ /* swap to new buffer space */
+ kfree(con->rx_buf);
+ con->rx_buflen = newlen;
+ con->rx_buf = newbuf;
+
+ return 0;
+}
+
+/* Data received from remote end */
+static int receive_from_sock(struct connection *con)
+{
+ struct msghdr msg;
+ struct kvec iov;
+ int ret, buflen;
+
+ mutex_lock(&con->sock_mutex);
+
+ if (con->sock == NULL) {
+ ret = -EAGAIN;
+ goto out_close;
+ }
+
+ /* realloc if we get new buffer size to read out */
+ buflen = dlm_config.ci_buffer_size;
+ if (con->rx_buflen != buflen && con->rx_leftover <= buflen) {
+ ret = con_realloc_receive_buf(con, buflen);
+ if (ret < 0)
+ goto out_resched;
+ }
+
+ for (;;) {
+ /* calculate new buffer parameter regarding last receive and
+ * possible leftover bytes
+ */
+ iov.iov_base = con->rx_buf + con->rx_leftover;
+ iov.iov_len = con->rx_buflen - con->rx_leftover;
+
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
+ ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len,
+ msg.msg_flags);
+ trace_dlm_recv(con->nodeid, ret);
+ if (ret == -EAGAIN)
+ break;
+ else if (ret <= 0)
+ goto out_close;
+
+ /* new buflen according readed bytes and leftover from last receive */
+ buflen = ret + con->rx_leftover;
+ ret = dlm_process_incoming_buffer(con->nodeid, con->rx_buf, buflen);
+ if (ret < 0)
+ goto out_close;
+
+ /* calculate leftover bytes from process and put it into begin of
+ * the receive buffer, so next receive we have the full message
+ * at the start address of the receive buffer.
+ */
+ con->rx_leftover = buflen - ret;
+ if (con->rx_leftover) {
+ memmove(con->rx_buf, con->rx_buf + ret,
+ con->rx_leftover);
+ }
+ }
+
+ dlm_midcomms_receive_done(con->nodeid);
+ mutex_unlock(&con->sock_mutex);
+ return 0;
+
+out_resched:
+ if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
+ queue_work(recv_workqueue, &con->rwork);
+ mutex_unlock(&con->sock_mutex);
+ return -EAGAIN;
+
+out_close:
+ if (ret == 0) {
+ log_print("connection %p got EOF from %d",
+ con, con->nodeid);
+
+ if (dlm_proto_ops->eof_condition &&
+ dlm_proto_ops->eof_condition(con)) {
+ set_bit(CF_EOF, &con->flags);
+ mutex_unlock(&con->sock_mutex);
+ } else {
+ mutex_unlock(&con->sock_mutex);
+ close_connection(con, false, true, false);
+
+ /* handling for tcp shutdown */
+ clear_bit(CF_SHUTDOWN, &con->flags);
+ wake_up(&con->shutdown_wait);
+ }
+
+ /* signal to breaking receive worker */
+ ret = -1;
+ } else {
+ mutex_unlock(&con->sock_mutex);
+ }
+ return ret;
+}
+
+/* Listening socket is busy, accept a connection */
+static int accept_from_sock(struct listen_connection *con)
+{
+ int result;
+ struct sockaddr_storage peeraddr;
+ struct socket *newsock;
+ int len, idx;
+ int nodeid;
+ struct connection *newcon;
+ struct connection *addcon;
+ unsigned int mark;
+
+ if (!con->sock)
+ return -ENOTCONN;
+
+ result = kernel_accept(con->sock, &newsock, O_NONBLOCK);
+ if (result < 0)
+ goto accept_err;
+
+ /* Get the connected socket's peer */
+ memset(&peeraddr, 0, sizeof(peeraddr));
+ len = newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 2);
+ if (len < 0) {
+ result = -ECONNABORTED;
+ goto accept_err;
+ }
+
+ /* Get the new node's NODEID */
+ make_sockaddr(&peeraddr, 0, &len);
+ if (addr_to_nodeid(&peeraddr, &nodeid, &mark)) {
+ switch (peeraddr.ss_family) {
+ case AF_INET: {
+ struct sockaddr_in *sin = (struct sockaddr_in *)&peeraddr;
+
+ log_print("connect from non cluster IPv4 node %pI4",
+ &sin->sin_addr);
+ break;
+ }
+#if IS_ENABLED(CONFIG_IPV6)
+ case AF_INET6: {
+ struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&peeraddr;
+
+ log_print("connect from non cluster IPv6 node %pI6c",
+ &sin6->sin6_addr);
+ break;
+ }
+#endif
+ default:
+ log_print("invalid family from non cluster node");
+ break;
+ }
+
+ sock_release(newsock);
+ return -1;
+ }
+
+ log_print("got connection from %d", nodeid);
+
+ /* Check to see if we already have a connection to this node. This
+ * could happen if the two nodes initiate a connection at roughly
+ * the same time and the connections cross on the wire.
+ * In this case we store the incoming one in "othercon"
+ */
+ idx = srcu_read_lock(&connections_srcu);
+ newcon = nodeid2con(nodeid, GFP_NOFS);
+ if (!newcon) {
+ srcu_read_unlock(&connections_srcu, idx);
+ result = -ENOMEM;
+ goto accept_err;
+ }
+
+ sock_set_mark(newsock->sk, mark);
+
+ mutex_lock(&newcon->sock_mutex);
+ if (newcon->sock) {
+ struct connection *othercon = newcon->othercon;
+
+ if (!othercon) {
+ othercon = kzalloc(sizeof(*othercon), GFP_NOFS);
+ if (!othercon) {
+ log_print("failed to allocate incoming socket");
+ mutex_unlock(&newcon->sock_mutex);
+ srcu_read_unlock(&connections_srcu, idx);
+ result = -ENOMEM;
+ goto accept_err;
+ }
+
+ result = dlm_con_init(othercon, nodeid);
+ if (result < 0) {
+ kfree(othercon);
+ mutex_unlock(&newcon->sock_mutex);
+ srcu_read_unlock(&connections_srcu, idx);
+ goto accept_err;
+ }
+
+ lockdep_set_subclass(&othercon->sock_mutex, 1);
+ set_bit(CF_IS_OTHERCON, &othercon->flags);
+ newcon->othercon = othercon;
+ othercon->sendcon = newcon;
+ } else {
+ /* close other sock con if we have something new */
+ close_connection(othercon, false, true, false);
+ }
+
+ mutex_lock(&othercon->sock_mutex);
+ add_sock(newsock, othercon);
+ addcon = othercon;
+ mutex_unlock(&othercon->sock_mutex);
+ }
+ else {
+ /* accept copies the sk after we've saved the callbacks, so we
+ don't want to save them a second time or comm errors will
+ result in calling sk_error_report recursively. */
+ add_sock(newsock, newcon);
+ addcon = newcon;
+ }
+
+ set_bit(CF_CONNECTED, &addcon->flags);
+ mutex_unlock(&newcon->sock_mutex);
+
+ /*
+ * Add it to the active queue in case we got data
+ * between processing the accept adding the socket
+ * to the read_sockets list
+ */
+ if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
+ queue_work(recv_workqueue, &addcon->rwork);
+
+ srcu_read_unlock(&connections_srcu, idx);
+
+ return 0;
+
+accept_err:
+ if (newsock)
+ sock_release(newsock);
+
+ if (result != -EAGAIN)
+ log_print("error accepting connection from node: %d", result);
+ return result;
+}
+
+/*
+ * writequeue_entry_complete - try to delete and free write queue entry
+ * @e: write queue entry to try to delete
+ * @completed: bytes completed
+ *
+ * writequeue_lock must be held.
+ */
+static void writequeue_entry_complete(struct writequeue_entry *e, int completed)
+{
+ e->offset += completed;
+ e->len -= completed;
+ /* signal that page was half way transmitted */
+ e->dirty = true;
+
+ if (e->len == 0 && e->users == 0)
+ free_entry(e);
+}
+
+/*
+ * sctp_bind_addrs - bind a SCTP socket to all our addresses
+ */
+static int sctp_bind_addrs(struct socket *sock, uint16_t port)
+{
+ struct sockaddr_storage localaddr;
+ struct sockaddr *addr = (struct sockaddr *)&localaddr;
+ int i, addr_len, result = 0;
+
+ for (i = 0; i < dlm_local_count; i++) {
+ memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
+ make_sockaddr(&localaddr, port, &addr_len);
+
+ if (!i)
+ result = kernel_bind(sock, addr, addr_len);
+ else
+ result = sock_bind_add(sock->sk, addr, addr_len);
+
+ if (result < 0) {
+ log_print("Can't bind to %d addr number %d, %d.\n",
+ port, i + 1, result);
+ break;
+ }
+ }
+ return result;
+}
+
+/* Get local addresses */
+static void init_local(void)
+{
+ struct sockaddr_storage sas, *addr;
+ int i;
+
+ dlm_local_count = 0;
+ for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) {
+ if (dlm_our_addr(&sas, i))
+ break;
+
+ addr = kmemdup(&sas, sizeof(*addr), GFP_NOFS);
+ if (!addr)
+ break;
+ dlm_local_addr[dlm_local_count++] = addr;
+ }
+}
+
+static void deinit_local(void)
+{
+ int i;
+
+ for (i = 0; i < dlm_local_count; i++)
+ kfree(dlm_local_addr[i]);
+}
+
+static struct writequeue_entry *new_writequeue_entry(struct connection *con)
+{
+ struct writequeue_entry *entry;
+
+ entry = dlm_allocate_writequeue();
+ if (!entry)
+ return NULL;
+
+ entry->page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
+ if (!entry->page) {
+ dlm_free_writequeue(entry);
+ return NULL;
+ }
+
+ entry->offset = 0;
+ entry->len = 0;
+ entry->end = 0;
+ entry->dirty = false;
+ entry->con = con;
+ entry->users = 1;
+ kref_init(&entry->ref);
+ return entry;
+}
+
+static struct writequeue_entry *new_wq_entry(struct connection *con, int len,
+ char **ppc, void (*cb)(void *data),
+ void *data)
+{
+ struct writequeue_entry *e;
+
+ spin_lock(&con->writequeue_lock);
+ if (!list_empty(&con->writequeue)) {
+ e = list_last_entry(&con->writequeue, struct writequeue_entry, list);
+ if (DLM_WQ_REMAIN_BYTES(e) >= len) {
+ kref_get(&e->ref);
+
+ *ppc = page_address(e->page) + e->end;
+ if (cb)
+ cb(data);
+
+ e->end += len;
+ e->users++;
+ goto out;
+ }
+ }
+
+ e = new_writequeue_entry(con);
+ if (!e)
+ goto out;
+
+ kref_get(&e->ref);
+ *ppc = page_address(e->page);
+ e->end += len;
+ atomic_inc(&con->writequeue_cnt);
+ if (cb)
+ cb(data);
+
+ list_add_tail(&e->list, &con->writequeue);
+
+out:
+ spin_unlock(&con->writequeue_lock);
+ return e;
+};
+
+static struct dlm_msg *dlm_lowcomms_new_msg_con(struct connection *con, int len,
+ gfp_t allocation, char **ppc,
+ void (*cb)(void *data),
+ void *data)
+{
+ struct writequeue_entry *e;
+ struct dlm_msg *msg;
+
+ msg = dlm_allocate_msg(allocation);
+ if (!msg)
+ return NULL;
+
+ kref_init(&msg->ref);
+
+ e = new_wq_entry(con, len, ppc, cb, data);
+ if (!e) {
+ dlm_free_msg(msg);
+ return NULL;
+ }
+
+ msg->retransmit = false;
+ msg->orig_msg = NULL;
+ msg->ppc = *ppc;
+ msg->len = len;
+ msg->entry = e;
+
+ return msg;
+}
+
+/* avoid false positive for nodes_srcu, unlock happens in
+ * dlm_lowcomms_commit_msg which is a must call if success
+ */
+#ifndef __CHECKER__
+struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation,
+ char **ppc, void (*cb)(void *data),
+ void *data)
+{
+ struct connection *con;
+ struct dlm_msg *msg;
+ int idx;
+
+ if (len > DLM_MAX_SOCKET_BUFSIZE ||
+ len < sizeof(struct dlm_header)) {
+ BUILD_BUG_ON(PAGE_SIZE < DLM_MAX_SOCKET_BUFSIZE);
+ log_print("failed to allocate a buffer of size %d", len);
+ WARN_ON(1);
+ return NULL;
+ }
+
+ idx = srcu_read_lock(&connections_srcu);
+ con = nodeid2con(nodeid, allocation);
+ if (!con) {
+ srcu_read_unlock(&connections_srcu, idx);
+ return NULL;
+ }
+
+ msg = dlm_lowcomms_new_msg_con(con, len, allocation, ppc, cb, data);
+ if (!msg) {
+ srcu_read_unlock(&connections_srcu, idx);
+ return NULL;
+ }
+
+ /* for dlm_lowcomms_commit_msg() */
+ kref_get(&msg->ref);
+ /* we assume if successful commit must called */
+ msg->idx = idx;
+ return msg;
+}
+#endif
+
+static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg)
+{
+ struct writequeue_entry *e = msg->entry;
+ struct connection *con = e->con;
+ int users;
+
+ spin_lock(&con->writequeue_lock);
+ kref_get(&msg->ref);
+ list_add(&msg->list, &e->msgs);
+
+ users = --e->users;
+ if (users)
+ goto out;
+
+ e->len = DLM_WQ_LENGTH_BYTES(e);
+ spin_unlock(&con->writequeue_lock);
+
+ queue_work(send_workqueue, &con->swork);
+ return;
+
+out:
+ spin_unlock(&con->writequeue_lock);
+ return;
+}
+
+/* avoid false positive for nodes_srcu, lock was happen in
+ * dlm_lowcomms_new_msg
+ */
+#ifndef __CHECKER__
+void dlm_lowcomms_commit_msg(struct dlm_msg *msg)
+{
+ _dlm_lowcomms_commit_msg(msg);
+ srcu_read_unlock(&connections_srcu, msg->idx);
+ /* because dlm_lowcomms_new_msg() */
+ kref_put(&msg->ref, dlm_msg_release);
+}
+#endif
+
+void dlm_lowcomms_put_msg(struct dlm_msg *msg)
+{
+ kref_put(&msg->ref, dlm_msg_release);
+}
+
+/* does not held connections_srcu, usage workqueue only */
+int dlm_lowcomms_resend_msg(struct dlm_msg *msg)
+{
+ struct dlm_msg *msg_resend;
+ char *ppc;
+
+ if (msg->retransmit)
+ return 1;
+
+ msg_resend = dlm_lowcomms_new_msg_con(msg->entry->con, msg->len,
+ GFP_ATOMIC, &ppc, NULL, NULL);
+ if (!msg_resend)
+ return -ENOMEM;
+
+ msg->retransmit = true;
+ kref_get(&msg->ref);
+ msg_resend->orig_msg = msg;
+
+ memcpy(ppc, msg->ppc, msg->len);
+ _dlm_lowcomms_commit_msg(msg_resend);
+ dlm_lowcomms_put_msg(msg_resend);
+
+ return 0;
+}
+
+/* Send a message */
+static void send_to_sock(struct connection *con)
+{
+ const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
+ struct writequeue_entry *e;
+ int len, offset, ret;
+ int count = 0;
+
+ mutex_lock(&con->sock_mutex);
+ if (con->sock == NULL)
+ goto out_connect;
+
+ spin_lock(&con->writequeue_lock);
+ for (;;) {
+ e = con_next_wq(con);
+ if (!e)
+ break;
+
+ len = e->len;
+ offset = e->offset;
+ BUG_ON(len == 0 && e->users == 0);
+ spin_unlock(&con->writequeue_lock);
+
+ ret = kernel_sendpage(con->sock, e->page, offset, len,
+ msg_flags);
+ trace_dlm_send(con->nodeid, ret);
+ if (ret == -EAGAIN || ret == 0) {
+ if (ret == -EAGAIN &&
+ test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) &&
+ !test_and_set_bit(CF_APP_LIMITED, &con->flags)) {
+ /* Notify TCP that we're limited by the
+ * application window size.
+ */
+ set_bit(SOCK_NOSPACE, &con->sock->flags);
+ con->sock->sk->sk_write_pending++;
+ }
+ cond_resched();
+ goto out;
+ } else if (ret < 0)
+ goto out;
+
+ /* Don't starve people filling buffers */
+ if (++count >= MAX_SEND_MSG_COUNT) {
+ cond_resched();
+ count = 0;
+ }
+
+ spin_lock(&con->writequeue_lock);
+ writequeue_entry_complete(e, ret);
+ }
+ spin_unlock(&con->writequeue_lock);
+
+ /* close if we got EOF */
+ if (test_and_clear_bit(CF_EOF, &con->flags)) {
+ mutex_unlock(&con->sock_mutex);
+ close_connection(con, false, false, true);
+
+ /* handling for tcp shutdown */
+ clear_bit(CF_SHUTDOWN, &con->flags);
+ wake_up(&con->shutdown_wait);
+ } else {
+ mutex_unlock(&con->sock_mutex);
+ }
+
+ return;
+
+out:
+ mutex_unlock(&con->sock_mutex);
+ return;
+
+out_connect:
+ mutex_unlock(&con->sock_mutex);
+ queue_work(send_workqueue, &con->swork);
+ cond_resched();
+}
+
+static void clean_one_writequeue(struct connection *con)
+{
+ struct writequeue_entry *e, *safe;
+
+ spin_lock(&con->writequeue_lock);
+ list_for_each_entry_safe(e, safe, &con->writequeue, list) {
+ free_entry(e);
+ }
+ spin_unlock(&con->writequeue_lock);
+}
+
+/* Called from recovery when it knows that a node has
+ left the cluster */
+int dlm_lowcomms_close(int nodeid)
+{
+ struct connection *con;
+ struct dlm_node_addr *na;
+ int idx;
+
+ log_print("closing connection to node %d", nodeid);
+ idx = srcu_read_lock(&connections_srcu);
+ con = nodeid2con(nodeid, 0);
+ if (con) {
+ set_bit(CF_CLOSE, &con->flags);
+ close_connection(con, true, true, true);
+ clean_one_writequeue(con);
+ if (con->othercon)
+ clean_one_writequeue(con->othercon);
+ }
+ srcu_read_unlock(&connections_srcu, idx);
+
+ spin_lock(&dlm_node_addrs_spin);
+ na = find_node_addr(nodeid);
+ if (na) {
+ list_del(&na->list);
+ while (na->addr_count--)
+ kfree(na->addr[na->addr_count]);
+ kfree(na);
+ }
+ spin_unlock(&dlm_node_addrs_spin);
+
+ return 0;
+}
+
+/* Receive workqueue function */
+static void process_recv_sockets(struct work_struct *work)
+{
+ struct connection *con = container_of(work, struct connection, rwork);
+
+ clear_bit(CF_READ_PENDING, &con->flags);
+ receive_from_sock(con);
+}
+
+static void process_listen_recv_socket(struct work_struct *work)
+{
+ int ret;
+
+ do {
+ ret = accept_from_sock(&listen_con);
+ } while (!ret);
+}
+
+static void dlm_connect(struct connection *con)
+{
+ struct sockaddr_storage addr;
+ int result, addr_len;
+ struct socket *sock;
+ unsigned int mark;
+
+ /* Some odd races can cause double-connects, ignore them */
+ if (con->retries++ > MAX_CONNECT_RETRIES)
+ return;
+
+ if (con->sock) {
+ log_print("node %d already connected.", con->nodeid);
+ return;
+ }
+
+ memset(&addr, 0, sizeof(addr));
+ result = nodeid_to_addr(con->nodeid, &addr, NULL,
+ dlm_proto_ops->try_new_addr, &mark);
+ if (result < 0) {
+ log_print("no address for nodeid %d", con->nodeid);
+ return;
+ }
+
+ /* Create a socket to communicate with */
+ result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
+ SOCK_STREAM, dlm_proto_ops->proto, &sock);
+ if (result < 0)
+ goto socket_err;
+
+ sock_set_mark(sock->sk, mark);
+ dlm_proto_ops->sockopts(sock);
+
+ add_sock(sock, con);
+
+ result = dlm_proto_ops->bind(sock);
+ if (result < 0)
+ goto add_sock_err;
+
+ log_print_ratelimited("connecting to %d", con->nodeid);
+ make_sockaddr(&addr, dlm_config.ci_tcp_port, &addr_len);
+ result = dlm_proto_ops->connect(con, sock, (struct sockaddr *)&addr,
+ addr_len);
+ if (result < 0)
+ goto add_sock_err;
+
+ return;
+
+add_sock_err:
+ dlm_close_sock(&con->sock);
+
+socket_err:
+ /*
+ * Some errors are fatal and this list might need adjusting. For other
+ * errors we try again until the max number of retries is reached.
+ */
+ if (result != -EHOSTUNREACH &&
+ result != -ENETUNREACH &&
+ result != -ENETDOWN &&
+ result != -EINVAL &&
+ result != -EPROTONOSUPPORT) {
+ log_print("connect %d try %d error %d", con->nodeid,
+ con->retries, result);
+ msleep(1000);
+ lowcomms_connect_sock(con);
+ }
+}
+
+/* Send workqueue function */
+static void process_send_sockets(struct work_struct *work)
+{
+ struct connection *con = container_of(work, struct connection, swork);
+
+ WARN_ON(test_bit(CF_IS_OTHERCON, &con->flags));
+
+ clear_bit(CF_WRITE_PENDING, &con->flags);
+
+ if (test_and_clear_bit(CF_RECONNECT, &con->flags)) {
+ close_connection(con, false, false, true);
+ dlm_midcomms_unack_msg_resend(con->nodeid);
+ }
+
+ if (con->sock == NULL) {
+ if (test_and_clear_bit(CF_DELAY_CONNECT, &con->flags))
+ msleep(1000);
+
+ mutex_lock(&con->sock_mutex);
+ dlm_connect(con);
+ mutex_unlock(&con->sock_mutex);
+ }
+
+ if (!list_empty(&con->writequeue))
+ send_to_sock(con);
+}
+
+static void work_stop(void)
+{
+ if (recv_workqueue) {
+ destroy_workqueue(recv_workqueue);
+ recv_workqueue = NULL;
+ }
+
+ if (send_workqueue) {
+ destroy_workqueue(send_workqueue);
+ send_workqueue = NULL;
+ }
+}
+
+static int work_start(void)
+{
+ recv_workqueue = alloc_ordered_workqueue("dlm_recv", WQ_MEM_RECLAIM);
+ if (!recv_workqueue) {
+ log_print("can't start dlm_recv");
+ return -ENOMEM;
+ }
+
+ send_workqueue = alloc_ordered_workqueue("dlm_send", WQ_MEM_RECLAIM);
+ if (!send_workqueue) {
+ log_print("can't start dlm_send");
+ destroy_workqueue(recv_workqueue);
+ recv_workqueue = NULL;
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void shutdown_conn(struct connection *con)
+{
+ if (dlm_proto_ops->shutdown_action)
+ dlm_proto_ops->shutdown_action(con);
+}
+
+void dlm_lowcomms_shutdown(void)
+{
+ int idx;
+
+ /* Set all the flags to prevent any
+ * socket activity.
+ */
+ dlm_allow_conn = 0;
+
+ if (recv_workqueue)
+ flush_workqueue(recv_workqueue);
+ if (send_workqueue)
+ flush_workqueue(send_workqueue);
+
+ dlm_close_sock(&listen_con.sock);
+
+ idx = srcu_read_lock(&connections_srcu);
+ foreach_conn(shutdown_conn);
+ srcu_read_unlock(&connections_srcu, idx);
+}
+
+static void _stop_conn(struct connection *con, bool and_other)
+{
+ mutex_lock(&con->sock_mutex);
+ set_bit(CF_CLOSE, &con->flags);
+ set_bit(CF_READ_PENDING, &con->flags);
+ set_bit(CF_WRITE_PENDING, &con->flags);
+ if (con->sock && con->sock->sk) {
+ lock_sock(con->sock->sk);
+ con->sock->sk->sk_user_data = NULL;
+ release_sock(con->sock->sk);
+ }
+ if (con->othercon && and_other)
+ _stop_conn(con->othercon, false);
+ mutex_unlock(&con->sock_mutex);
+}
+
+static void stop_conn(struct connection *con)
+{
+ _stop_conn(con, true);
+}
+
+static void connection_release(struct rcu_head *rcu)
+{
+ struct connection *con = container_of(rcu, struct connection, rcu);
+
+ kfree(con->rx_buf);
+ kfree(con);
+}
+
+static void free_conn(struct connection *con)
+{
+ close_connection(con, true, true, true);
+ spin_lock(&connections_lock);
+ hlist_del_rcu(&con->list);
+ spin_unlock(&connections_lock);
+ if (con->othercon) {
+ clean_one_writequeue(con->othercon);
+ call_srcu(&connections_srcu, &con->othercon->rcu,
+ connection_release);
+ }
+ clean_one_writequeue(con);
+ call_srcu(&connections_srcu, &con->rcu, connection_release);
+}
+
+static void work_flush(void)
+{
+ int ok;
+ int i;
+ struct connection *con;
+
+ do {
+ ok = 1;
+ foreach_conn(stop_conn);
+ if (recv_workqueue)
+ flush_workqueue(recv_workqueue);
+ if (send_workqueue)
+ flush_workqueue(send_workqueue);
+ for (i = 0; i < CONN_HASH_SIZE && ok; i++) {
+ hlist_for_each_entry_rcu(con, &connection_hash[i],
+ list) {
+ ok &= test_bit(CF_READ_PENDING, &con->flags);
+ ok &= test_bit(CF_WRITE_PENDING, &con->flags);
+ if (con->othercon) {
+ ok &= test_bit(CF_READ_PENDING,
+ &con->othercon->flags);
+ ok &= test_bit(CF_WRITE_PENDING,
+ &con->othercon->flags);
+ }
+ }
+ }
+ } while (!ok);
+}
+
+void dlm_lowcomms_stop(void)
+{
+ int idx;
+
+ idx = srcu_read_lock(&connections_srcu);
+ work_flush();
+ foreach_conn(free_conn);
+ srcu_read_unlock(&connections_srcu, idx);
+ work_stop();
+ deinit_local();
+
+ dlm_proto_ops = NULL;
+}
+
+static int dlm_listen_for_all(void)
+{
+ struct socket *sock;
+ int result;
+
+ log_print("Using %s for communications",
+ dlm_proto_ops->name);
+
+ result = dlm_proto_ops->listen_validate();
+ if (result < 0)
+ return result;
+
+ result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
+ SOCK_STREAM, dlm_proto_ops->proto, &sock);
+ if (result < 0) {
+ log_print("Can't create comms socket: %d", result);
+ return result;
+ }
+
+ sock_set_mark(sock->sk, dlm_config.ci_mark);
+ dlm_proto_ops->listen_sockopts(sock);
+
+ result = dlm_proto_ops->listen_bind(sock);
+ if (result < 0)
+ goto out;
+
+ save_listen_callbacks(sock);
+ add_listen_sock(sock, &listen_con);
+
+ INIT_WORK(&listen_con.rwork, process_listen_recv_socket);
+ result = sock->ops->listen(sock, 5);
+ if (result < 0) {
+ dlm_close_sock(&listen_con.sock);
+ return result;
+ }
+
+ return 0;
+
+out:
+ sock_release(sock);
+ return result;
+}
+
+static int dlm_tcp_bind(struct socket *sock)
+{
+ struct sockaddr_storage src_addr;
+ int result, addr_len;
+
+ /* Bind to our cluster-known address connecting to avoid
+ * routing problems.
+ */
+ memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr));
+ make_sockaddr(&src_addr, 0, &addr_len);
+
+ result = kernel_bind(sock, (struct sockaddr *)&src_addr,
+ addr_len);
+ if (result < 0) {
+ /* This *may* not indicate a critical error */
+ log_print("could not bind for connect: %d", result);
+ }
+
+ return 0;
+}
+
+static int dlm_tcp_connect(struct connection *con, struct socket *sock,
+ struct sockaddr *addr, int addr_len)
+{
+ int ret;
+
+ ret = kernel_connect(sock, addr, addr_len, O_NONBLOCK);
+ switch (ret) {
+ case -EINPROGRESS:
+ fallthrough;
+ case 0:
+ return 0;
+ }
+
+ return ret;
+}
+
+static int dlm_tcp_listen_validate(void)
+{
+ /* We don't support multi-homed hosts */
+ if (dlm_local_count > 1) {
+ log_print("TCP protocol can't handle multi-homed hosts, try SCTP");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void dlm_tcp_sockopts(struct socket *sock)
+{
+ /* Turn off Nagle's algorithm */
+ tcp_sock_set_nodelay(sock->sk);
+}
+
+static void dlm_tcp_listen_sockopts(struct socket *sock)
+{
+ dlm_tcp_sockopts(sock);
+ sock_set_reuseaddr(sock->sk);
+}
+
+static int dlm_tcp_listen_bind(struct socket *sock)
+{
+ int addr_len;
+
+ /* Bind to our port */
+ make_sockaddr(dlm_local_addr[0], dlm_config.ci_tcp_port, &addr_len);
+ return kernel_bind(sock, (struct sockaddr *)&dlm_local_addr[0],
+ addr_len);
+}
+
+static const struct dlm_proto_ops dlm_tcp_ops = {
+ .name = "TCP",
+ .proto = IPPROTO_TCP,
+ .connect = dlm_tcp_connect,
+ .sockopts = dlm_tcp_sockopts,
+ .bind = dlm_tcp_bind,
+ .listen_validate = dlm_tcp_listen_validate,
+ .listen_sockopts = dlm_tcp_listen_sockopts,
+ .listen_bind = dlm_tcp_listen_bind,
+ .shutdown_action = dlm_tcp_shutdown,
+ .eof_condition = tcp_eof_condition,
+};
+
+static int dlm_sctp_bind(struct socket *sock)
+{
+ return sctp_bind_addrs(sock, 0);
+}
+
+static int dlm_sctp_connect(struct connection *con, struct socket *sock,
+ struct sockaddr *addr, int addr_len)
+{
+ int ret;
+
+ /*
+ * Make kernel_connect() function return in specified time,
+ * since O_NONBLOCK argument in connect() function does not work here,
+ * then, we should restore the default value of this attribute.
+ */
+ sock_set_sndtimeo(sock->sk, 5);
+ ret = kernel_connect(sock, addr, addr_len, 0);
+ sock_set_sndtimeo(sock->sk, 0);
+ if (ret < 0)
+ return ret;
+
+ if (!test_and_set_bit(CF_CONNECTED, &con->flags))
+ log_print("connected to node %d", con->nodeid);
+
+ return 0;
+}
+
+static int dlm_sctp_listen_validate(void)
+{
+ if (!IS_ENABLED(CONFIG_IP_SCTP)) {
+ log_print("SCTP is not enabled by this kernel");
+ return -EOPNOTSUPP;
+ }
+
+ request_module("sctp");
+ return 0;
+}
+
+static int dlm_sctp_bind_listen(struct socket *sock)
+{
+ return sctp_bind_addrs(sock, dlm_config.ci_tcp_port);
+}
+
+static void dlm_sctp_sockopts(struct socket *sock)
+{
+ /* Turn off Nagle's algorithm */
+ sctp_sock_set_nodelay(sock->sk);
+ sock_set_rcvbuf(sock->sk, NEEDED_RMEM);
+}
+
+static const struct dlm_proto_ops dlm_sctp_ops = {
+ .name = "SCTP",
+ .proto = IPPROTO_SCTP,
+ .try_new_addr = true,
+ .connect = dlm_sctp_connect,
+ .sockopts = dlm_sctp_sockopts,
+ .bind = dlm_sctp_bind,
+ .listen_validate = dlm_sctp_listen_validate,
+ .listen_sockopts = dlm_sctp_sockopts,
+ .listen_bind = dlm_sctp_bind_listen,
+};
+
+int dlm_lowcomms_start(void)
+{
+ int error = -EINVAL;
+
+ init_local();
+ if (!dlm_local_count) {
+ error = -ENOTCONN;
+ log_print("no local IP address has been set");
+ goto fail;
+ }
+
+ error = work_start();
+ if (error)
+ goto fail_local;
+
+ dlm_allow_conn = 1;
+
+ /* Start listening */
+ switch (dlm_config.ci_protocol) {
+ case DLM_PROTO_TCP:
+ dlm_proto_ops = &dlm_tcp_ops;
+ break;
+ case DLM_PROTO_SCTP:
+ dlm_proto_ops = &dlm_sctp_ops;
+ break;
+ default:
+ log_print("Invalid protocol identifier %d set",
+ dlm_config.ci_protocol);
+ error = -EINVAL;
+ goto fail_proto_ops;
+ }
+
+ error = dlm_listen_for_all();
+ if (error)
+ goto fail_listen;
+
+ return 0;
+
+fail_listen:
+ dlm_proto_ops = NULL;
+fail_proto_ops:
+ dlm_allow_conn = 0;
+ work_stop();
+fail_local:
+ deinit_local();
+fail:
+ return error;
+}
+
+void dlm_lowcomms_init(void)
+{
+ int i;
+
+ for (i = 0; i < CONN_HASH_SIZE; i++)
+ INIT_HLIST_HEAD(&connection_hash[i]);
+
+ INIT_WORK(&listen_con.rwork, process_listen_recv_socket);
+}
+
+void dlm_lowcomms_exit(void)
+{
+ struct 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);
+}