blob: cdb580a9c7a28352e903fa660c848826966b9dc1 [file] [log] [blame]
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001/******************************************************************************
2*******************************************************************************
3**
4** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06005** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
Patrick Caulfield6ed72572007-04-17 15:39:57 +01006**
7** This copyrighted material is made available to anyone wishing to use,
8** modify, copy, or redistribute it subject to the terms and conditions
9** of the GNU General Public License v.2.
10**
11*******************************************************************************
12******************************************************************************/
13
14/*
15 * lowcomms.c
16 *
17 * This is the "low-level" comms layer.
18 *
19 * It is responsible for sending/receiving messages
20 * from other nodes in the cluster.
21 *
22 * Cluster nodes are referred to by their nodeids. nodeids are
23 * simply 32 bit numbers to the locking module - if they need to
Joe Perches2cf12c02009-01-22 13:26:47 -080024 * be expanded for the cluster infrastructure then that is its
Patrick Caulfield6ed72572007-04-17 15:39:57 +010025 * responsibility. It is this layer's
26 * responsibility to resolve these into IP address or
27 * whatever it needs for inter-node communication.
28 *
29 * The comms level is two kernel threads that deal mainly with
30 * the receiving of messages from other nodes and passing them
31 * up to the mid-level comms layer (which understands the
32 * message format) for execution by the locking core, and
33 * a send thread which does all the setting up of connections
34 * to remote nodes and the sending of data. Threads are not allowed
35 * to send their own data because it may cause them to wait in times
36 * of high load. Also, this way, the sending thread can collect together
37 * messages bound for one node and send them in one block.
38 *
Joe Perches2cf12c02009-01-22 13:26:47 -080039 * lowcomms will choose to use either TCP or SCTP as its transport layer
Patrick Caulfield6ed72572007-04-17 15:39:57 +010040 * depending on the configuration variable 'protocol'. This should be set
Joe Perches2cf12c02009-01-22 13:26:47 -080041 * to 0 (default) for TCP or 1 for SCTP. It should be configured using a
Patrick Caulfield6ed72572007-04-17 15:39:57 +010042 * cluster-wide mechanism as it must be the same on all nodes of the cluster
43 * for the DLM to function.
44 *
45 */
46
47#include <asm/ioctls.h>
48#include <net/sock.h>
49#include <net/tcp.h>
50#include <linux/pagemap.h>
Patrick Caulfield6ed72572007-04-17 15:39:57 +010051#include <linux/file.h>
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -050052#include <linux/mutex.h>
Patrick Caulfield6ed72572007-04-17 15:39:57 +010053#include <linux/sctp.h>
54#include <net/sctp/user.h>
Joe Perches44ad5322009-01-22 13:24:49 -080055#include <net/ipv6.h>
Patrick Caulfield6ed72572007-04-17 15:39:57 +010056
57#include "dlm_internal.h"
58#include "lowcomms.h"
59#include "midcomms.h"
60#include "config.h"
61
62#define NEEDED_RMEM (4*1024*1024)
Christine Caulfield5e9ccc32009-01-28 12:57:40 -060063#define CONN_HASH_SIZE 32
Patrick Caulfield6ed72572007-04-17 15:39:57 +010064
65struct cbuf {
66 unsigned int base;
67 unsigned int len;
68 unsigned int mask;
69};
70
71static void cbuf_add(struct cbuf *cb, int n)
72{
73 cb->len += n;
74}
75
76static int cbuf_data(struct cbuf *cb)
77{
78 return ((cb->base + cb->len) & cb->mask);
79}
80
81static void cbuf_init(struct cbuf *cb, int size)
82{
83 cb->base = cb->len = 0;
84 cb->mask = size-1;
85}
86
87static void cbuf_eat(struct cbuf *cb, int n)
88{
89 cb->len -= n;
90 cb->base += n;
91 cb->base &= cb->mask;
92}
93
94static bool cbuf_empty(struct cbuf *cb)
95{
96 return cb->len == 0;
97}
98
99struct connection {
100 struct socket *sock; /* NULL if not connected */
101 uint32_t nodeid; /* So we know who we are in the list */
102 struct mutex sock_mutex;
103 unsigned long flags;
104#define CF_READ_PENDING 1
105#define CF_WRITE_PENDING 2
106#define CF_CONNECT_PENDING 3
107#define CF_INIT_PENDING 4
108#define CF_IS_OTHERCON 5
109 struct list_head writequeue; /* List of outgoing writequeue_entries */
110 spinlock_t writequeue_lock;
111 int (*rx_action) (struct connection *); /* What to do when active */
112 void (*connect_action) (struct connection *); /* What to do to connect */
113 struct page *rx_page;
114 struct cbuf cb;
115 int retries;
116#define MAX_CONNECT_RETRIES 3
117 int sctp_assoc;
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600118 struct hlist_node list;
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100119 struct connection *othercon;
120 struct work_struct rwork; /* Receive workqueue */
121 struct work_struct swork; /* Send workqueue */
122};
123#define sock2con(x) ((struct connection *)(x)->sk_user_data)
124
125/* An entry waiting to be sent */
126struct writequeue_entry {
127 struct list_head list;
128 struct page *page;
129 int offset;
130 int len;
131 int end;
132 int users;
133 struct connection *con;
134};
135
136static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
137static int dlm_local_count;
138
139/* Work queues */
140static struct workqueue_struct *recv_workqueue;
141static struct workqueue_struct *send_workqueue;
142
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600143static struct hlist_head connection_hash[CONN_HASH_SIZE];
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500144static DEFINE_MUTEX(connections_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100145static struct kmem_cache *con_cache;
146
147static void process_recv_sockets(struct work_struct *work);
148static void process_send_sockets(struct work_struct *work);
149
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600150
151/* This is deliberately very simple because most clusters have simple
152 sequential nodeids, so we should be able to go straight to a connection
153 struct in the array */
154static inline int nodeid_hash(int nodeid)
155{
156 return nodeid & (CONN_HASH_SIZE-1);
157}
158
159static struct connection *__find_con(int nodeid)
160{
161 int r;
162 struct hlist_node *h;
163 struct connection *con;
164
165 r = nodeid_hash(nodeid);
166
167 hlist_for_each_entry(con, h, &connection_hash[r], list) {
168 if (con->nodeid == nodeid)
169 return con;
170 }
171 return NULL;
172}
173
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100174/*
175 * If 'allocation' is zero then we don't attempt to create a new
176 * connection structure for this node.
177 */
178static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
179{
180 struct connection *con = NULL;
181 int r;
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100182
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600183 con = __find_con(nodeid);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100184 if (con || !alloc)
185 return con;
186
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100187 con = kmem_cache_zalloc(con_cache, alloc);
188 if (!con)
189 return NULL;
190
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600191 r = nodeid_hash(nodeid);
192 hlist_add_head(&con->list, &connection_hash[r]);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100193
194 con->nodeid = nodeid;
195 mutex_init(&con->sock_mutex);
196 INIT_LIST_HEAD(&con->writequeue);
197 spin_lock_init(&con->writequeue_lock);
198 INIT_WORK(&con->swork, process_send_sockets);
199 INIT_WORK(&con->rwork, process_recv_sockets);
200
201 /* Setup action pointers for child sockets */
202 if (con->nodeid) {
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600203 struct connection *zerocon = __find_con(0);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100204
205 con->connect_action = zerocon->connect_action;
206 if (!con->rx_action)
207 con->rx_action = zerocon->rx_action;
208 }
209
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100210 return con;
211}
212
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600213/* Loop round all connections */
214static void foreach_conn(void (*conn_func)(struct connection *c))
215{
216 int i;
217 struct hlist_node *h, *n;
218 struct connection *con;
219
220 for (i = 0; i < CONN_HASH_SIZE; i++) {
221 hlist_for_each_entry_safe(con, h, n, &connection_hash[i], list){
222 conn_func(con);
223 }
224 }
225}
226
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100227static struct connection *nodeid2con(int nodeid, gfp_t allocation)
228{
229 struct connection *con;
230
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500231 mutex_lock(&connections_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100232 con = __nodeid2con(nodeid, allocation);
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500233 mutex_unlock(&connections_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100234
235 return con;
236}
237
238/* This is a bit drastic, but only called when things go wrong */
239static struct connection *assoc2con(int assoc_id)
240{
241 int i;
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600242 struct hlist_node *h;
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100243 struct connection *con;
244
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500245 mutex_lock(&connections_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600246
247 for (i = 0 ; i < CONN_HASH_SIZE; i++) {
248 hlist_for_each_entry(con, h, &connection_hash[i], list) {
249 if (con && con->sctp_assoc == assoc_id) {
250 mutex_unlock(&connections_lock);
251 return con;
252 }
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100253 }
254 }
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500255 mutex_unlock(&connections_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100256 return NULL;
257}
258
259static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
260{
261 struct sockaddr_storage addr;
262 int error;
263
264 if (!dlm_local_count)
265 return -1;
266
267 error = dlm_nodeid_to_addr(nodeid, &addr);
268 if (error)
269 return error;
270
271 if (dlm_local_addr[0]->ss_family == AF_INET) {
272 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr;
273 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr;
274 ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
275 } else {
276 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr;
277 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr;
Joe Perches44ad5322009-01-22 13:24:49 -0800278 ipv6_addr_copy(&ret6->sin6_addr, &in6->sin6_addr);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100279 }
280
281 return 0;
282}
283
284/* Data available on socket or listen socket received a connect */
285static void lowcomms_data_ready(struct sock *sk, int count_unused)
286{
287 struct connection *con = sock2con(sk);
Patrick Caulfieldafb853f2007-06-01 10:07:26 -0500288 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags))
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100289 queue_work(recv_workqueue, &con->rwork);
290}
291
292static void lowcomms_write_space(struct sock *sk)
293{
294 struct connection *con = sock2con(sk);
295
Patrick Caulfieldafb853f2007-06-01 10:07:26 -0500296 if (con && !test_and_set_bit(CF_WRITE_PENDING, &con->flags))
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100297 queue_work(send_workqueue, &con->swork);
298}
299
300static inline void lowcomms_connect_sock(struct connection *con)
301{
302 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
303 queue_work(send_workqueue, &con->swork);
304}
305
306static void lowcomms_state_change(struct sock *sk)
307{
308 if (sk->sk_state == TCP_ESTABLISHED)
309 lowcomms_write_space(sk);
310}
311
Christine Caulfield391fbdc2009-05-07 10:54:16 -0500312int dlm_lowcomms_connect_node(int nodeid)
313{
314 struct connection *con;
315
316 if (nodeid == dlm_our_nodeid())
317 return 0;
318
319 con = nodeid2con(nodeid, GFP_NOFS);
320 if (!con)
321 return -ENOMEM;
322 lowcomms_connect_sock(con);
323 return 0;
324}
325
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100326/* Make a socket active */
327static int add_sock(struct socket *sock, struct connection *con)
328{
329 con->sock = sock;
330
331 /* Install a data_ready callback */
332 con->sock->sk->sk_data_ready = lowcomms_data_ready;
333 con->sock->sk->sk_write_space = lowcomms_write_space;
334 con->sock->sk->sk_state_change = lowcomms_state_change;
335 con->sock->sk->sk_user_data = con;
Steven Whitehoused6d7b702008-11-12 16:49:48 -0600336 con->sock->sk->sk_allocation = GFP_NOFS;
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100337 return 0;
338}
339
340/* Add the port number to an IPv6 or 4 sockaddr and return the address
341 length */
342static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
343 int *addr_len)
344{
345 saddr->ss_family = dlm_local_addr[0]->ss_family;
346 if (saddr->ss_family == AF_INET) {
347 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
348 in4_addr->sin_port = cpu_to_be16(port);
349 *addr_len = sizeof(struct sockaddr_in);
350 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
351 } else {
352 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
353 in6_addr->sin6_port = cpu_to_be16(port);
354 *addr_len = sizeof(struct sockaddr_in6);
355 }
Patrick Caulfield01c8cab2007-07-17 16:53:15 +0100356 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100357}
358
359/* Close a remote connection and tidy up */
360static void close_connection(struct connection *con, bool and_other)
361{
362 mutex_lock(&con->sock_mutex);
363
364 if (con->sock) {
365 sock_release(con->sock);
366 con->sock = NULL;
367 }
368 if (con->othercon && and_other) {
369 /* Will only re-enter once. */
370 close_connection(con->othercon, false);
371 }
372 if (con->rx_page) {
373 __free_page(con->rx_page);
374 con->rx_page = NULL;
375 }
Patrick Caulfield9e5f2822007-08-02 14:58:14 +0100376
Patrick Caulfield61d96be2007-08-20 15:13:38 +0100377 con->retries = 0;
378 mutex_unlock(&con->sock_mutex);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100379}
380
381/* We only send shutdown messages to nodes that are not part of the cluster */
382static void sctp_send_shutdown(sctp_assoc_t associd)
383{
384 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
385 struct msghdr outmessage;
386 struct cmsghdr *cmsg;
387 struct sctp_sndrcvinfo *sinfo;
388 int ret;
389 struct connection *con;
390
391 con = nodeid2con(0,0);
392 BUG_ON(con == NULL);
393
394 outmessage.msg_name = NULL;
395 outmessage.msg_namelen = 0;
396 outmessage.msg_control = outcmsg;
397 outmessage.msg_controllen = sizeof(outcmsg);
398 outmessage.msg_flags = MSG_EOR;
399
400 cmsg = CMSG_FIRSTHDR(&outmessage);
401 cmsg->cmsg_level = IPPROTO_SCTP;
402 cmsg->cmsg_type = SCTP_SNDRCV;
403 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
404 outmessage.msg_controllen = cmsg->cmsg_len;
405 sinfo = CMSG_DATA(cmsg);
406 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
407
408 sinfo->sinfo_flags |= MSG_EOF;
409 sinfo->sinfo_assoc_id = associd;
410
411 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0);
412
413 if (ret != 0)
414 log_print("send EOF to node failed: %d", ret);
415}
416
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600417static void sctp_init_failed_foreach(struct connection *con)
418{
419 con->sctp_assoc = 0;
420 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
421 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
422 queue_work(send_workqueue, &con->swork);
423 }
424}
425
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100426/* INIT failed but we don't know which node...
427 restart INIT on all pending nodes */
428static void sctp_init_failed(void)
429{
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500430 mutex_lock(&connections_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600431
432 foreach_conn(sctp_init_failed_foreach);
433
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500434 mutex_unlock(&connections_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100435}
436
437/* Something happened to an association */
David Teigland617e82e2007-04-26 13:46:49 -0500438static void process_sctp_notification(struct connection *con,
439 struct msghdr *msg, char *buf)
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100440{
441 union sctp_notification *sn = (union sctp_notification *)buf;
442
443 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
444 switch (sn->sn_assoc_change.sac_state) {
445
446 case SCTP_COMM_UP:
447 case SCTP_RESTART:
448 {
449 /* Check that the new node is in the lockspace */
450 struct sctp_prim prim;
451 int nodeid;
452 int prim_len, ret;
453 int addr_len;
454 struct connection *new_con;
455 struct file *file;
456 sctp_peeloff_arg_t parg;
457 int parglen = sizeof(parg);
458
459 /*
460 * We get this before any data for an association.
461 * We verify that the node is in the cluster and
462 * then peel off a socket for it.
463 */
464 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
465 log_print("COMM_UP for invalid assoc ID %d",
David Teigland617e82e2007-04-26 13:46:49 -0500466 (int)sn->sn_assoc_change.sac_assoc_id);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100467 sctp_init_failed();
468 return;
469 }
470 memset(&prim, 0, sizeof(struct sctp_prim));
471 prim_len = sizeof(struct sctp_prim);
472 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
473
474 ret = kernel_getsockopt(con->sock,
475 IPPROTO_SCTP,
476 SCTP_PRIMARY_ADDR,
477 (char*)&prim,
478 &prim_len);
479 if (ret < 0) {
480 log_print("getsockopt/sctp_primary_addr on "
481 "new assoc %d failed : %d",
482 (int)sn->sn_assoc_change.sac_assoc_id,
483 ret);
484
485 /* Retry INIT later */
486 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
487 if (new_con)
488 clear_bit(CF_CONNECT_PENDING, &con->flags);
489 return;
490 }
491 make_sockaddr(&prim.ssp_addr, 0, &addr_len);
492 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
493 int i;
494 unsigned char *b=(unsigned char *)&prim.ssp_addr;
495 log_print("reject connect from unknown addr");
496 for (i=0; i<sizeof(struct sockaddr_storage);i++)
497 printk("%02x ", b[i]);
498 printk("\n");
499 sctp_send_shutdown(prim.ssp_assoc_id);
500 return;
501 }
502
David Teigland748285c2009-05-15 10:50:57 -0500503 new_con = nodeid2con(nodeid, GFP_NOFS);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100504 if (!new_con)
505 return;
506
507 /* Peel off a new sock */
508 parg.associd = sn->sn_assoc_change.sac_assoc_id;
David Teigland617e82e2007-04-26 13:46:49 -0500509 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP,
510 SCTP_SOCKOPT_PEELOFF,
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100511 (void *)&parg, &parglen);
Patrick Caulfield30d3a232007-04-23 16:26:21 +0100512 if (ret) {
David Teigland617e82e2007-04-26 13:46:49 -0500513 log_print("Can't peel off a socket for "
514 "connection %d to node %d: err=%d\n",
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100515 parg.associd, nodeid, ret);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100516 }
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100517 file = fget(parg.sd);
518 new_con->sock = SOCKET_I(file->f_dentry->d_inode);
519 add_sock(new_con->sock, new_con);
520 fput(file);
521 put_unused_fd(parg.sd);
522
523 log_print("got new/restarted association %d nodeid %d",
David Teigland617e82e2007-04-26 13:46:49 -0500524 (int)sn->sn_assoc_change.sac_assoc_id, nodeid);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100525
526 /* Send any pending writes */
527 clear_bit(CF_CONNECT_PENDING, &new_con->flags);
528 clear_bit(CF_INIT_PENDING, &con->flags);
529 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) {
530 queue_work(send_workqueue, &new_con->swork);
531 }
532 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags))
533 queue_work(recv_workqueue, &new_con->rwork);
534 }
535 break;
536
537 case SCTP_COMM_LOST:
538 case SCTP_SHUTDOWN_COMP:
539 {
540 con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
541 if (con) {
542 con->sctp_assoc = 0;
543 }
544 }
545 break;
546
547 /* We don't know which INIT failed, so clear the PENDING flags
548 * on them all. if assoc_id is zero then it will then try
549 * again */
550
551 case SCTP_CANT_STR_ASSOC:
552 {
553 log_print("Can't start SCTP association - retrying");
554 sctp_init_failed();
555 }
556 break;
557
558 default:
559 log_print("unexpected SCTP assoc change id=%d state=%d",
560 (int)sn->sn_assoc_change.sac_assoc_id,
561 sn->sn_assoc_change.sac_state);
562 }
563 }
564}
565
566/* Data received from remote end */
567static int receive_from_sock(struct connection *con)
568{
569 int ret = 0;
570 struct msghdr msg = {};
571 struct kvec iov[2];
572 unsigned len;
573 int r;
574 int call_again_soon = 0;
575 int nvec;
576 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
577
578 mutex_lock(&con->sock_mutex);
579
580 if (con->sock == NULL) {
581 ret = -EAGAIN;
582 goto out_close;
583 }
584
585 if (con->rx_page == NULL) {
586 /*
587 * This doesn't need to be atomic, but I think it should
588 * improve performance if it is.
589 */
590 con->rx_page = alloc_page(GFP_ATOMIC);
591 if (con->rx_page == NULL)
592 goto out_resched;
593 cbuf_init(&con->cb, PAGE_CACHE_SIZE);
594 }
595
596 /* Only SCTP needs these really */
597 memset(&incmsg, 0, sizeof(incmsg));
598 msg.msg_control = incmsg;
599 msg.msg_controllen = sizeof(incmsg);
600
601 /*
602 * iov[0] is the bit of the circular buffer between the current end
603 * point (cb.base + cb.len) and the end of the buffer.
604 */
605 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
606 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
607 iov[1].iov_len = 0;
608 nvec = 1;
609
610 /*
611 * iov[1] is the bit of the circular buffer between the start of the
612 * buffer and the start of the currently used section (cb.base)
613 */
614 if (cbuf_data(&con->cb) >= con->cb.base) {
615 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);
616 iov[1].iov_len = con->cb.base;
617 iov[1].iov_base = page_address(con->rx_page);
618 nvec = 2;
619 }
620 len = iov[0].iov_len + iov[1].iov_len;
621
622 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
623 MSG_DONTWAIT | MSG_NOSIGNAL);
624 if (ret <= 0)
625 goto out_close;
626
627 /* Process SCTP notifications */
628 if (msg.msg_flags & MSG_NOTIFICATION) {
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100629 msg.msg_control = incmsg;
630 msg.msg_controllen = sizeof(incmsg);
631
632 process_sctp_notification(con, &msg,
David Teigland617e82e2007-04-26 13:46:49 -0500633 page_address(con->rx_page) + con->cb.base);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100634 mutex_unlock(&con->sock_mutex);
635 return 0;
636 }
637 BUG_ON(con->nodeid == 0);
638
639 if (ret == len)
640 call_again_soon = 1;
641 cbuf_add(&con->cb, ret);
642 ret = dlm_process_incoming_buffer(con->nodeid,
643 page_address(con->rx_page),
644 con->cb.base, con->cb.len,
645 PAGE_CACHE_SIZE);
646 if (ret == -EBADMSG) {
David Teigland617e82e2007-04-26 13:46:49 -0500647 log_print("lowcomms: addr=%p, base=%u, len=%u, "
648 "iov_len=%u, iov_base[0]=%p, read=%d",
649 page_address(con->rx_page), con->cb.base, con->cb.len,
650 len, iov[0].iov_base, r);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100651 }
652 if (ret < 0)
653 goto out_close;
654 cbuf_eat(&con->cb, ret);
655
656 if (cbuf_empty(&con->cb) && !call_again_soon) {
657 __free_page(con->rx_page);
658 con->rx_page = NULL;
659 }
660
661 if (call_again_soon)
662 goto out_resched;
663 mutex_unlock(&con->sock_mutex);
664 return 0;
665
666out_resched:
667 if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
668 queue_work(recv_workqueue, &con->rwork);
669 mutex_unlock(&con->sock_mutex);
670 return -EAGAIN;
671
672out_close:
673 mutex_unlock(&con->sock_mutex);
Patrick Caulfield9e5f2822007-08-02 14:58:14 +0100674 if (ret != -EAGAIN) {
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100675 close_connection(con, false);
676 /* Reconnect when there is something to send */
677 }
678 /* Don't return success if we really got EOF */
679 if (ret == 0)
680 ret = -EAGAIN;
681
682 return ret;
683}
684
685/* Listening socket is busy, accept a connection */
686static int tcp_accept_from_sock(struct connection *con)
687{
688 int result;
689 struct sockaddr_storage peeraddr;
690 struct socket *newsock;
691 int len;
692 int nodeid;
693 struct connection *newcon;
694 struct connection *addcon;
695
696 memset(&peeraddr, 0, sizeof(peeraddr));
697 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
698 IPPROTO_TCP, &newsock);
699 if (result < 0)
700 return -ENOMEM;
701
702 mutex_lock_nested(&con->sock_mutex, 0);
703
704 result = -ENOTCONN;
705 if (con->sock == NULL)
706 goto accept_err;
707
708 newsock->type = con->sock->type;
709 newsock->ops = con->sock->ops;
710
711 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
712 if (result < 0)
713 goto accept_err;
714
715 /* Get the connected socket's peer */
716 memset(&peeraddr, 0, sizeof(peeraddr));
717 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
718 &len, 2)) {
719 result = -ECONNABORTED;
720 goto accept_err;
721 }
722
723 /* Get the new node's NODEID */
724 make_sockaddr(&peeraddr, 0, &len);
725 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
David Teigland617e82e2007-04-26 13:46:49 -0500726 log_print("connect from non cluster node");
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100727 sock_release(newsock);
728 mutex_unlock(&con->sock_mutex);
729 return -1;
730 }
731
732 log_print("got connection from %d", nodeid);
733
734 /* Check to see if we already have a connection to this node. This
735 * could happen if the two nodes initiate a connection at roughly
736 * the same time and the connections cross on the wire.
737 * In this case we store the incoming one in "othercon"
738 */
David Teigland748285c2009-05-15 10:50:57 -0500739 newcon = nodeid2con(nodeid, GFP_NOFS);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100740 if (!newcon) {
741 result = -ENOMEM;
742 goto accept_err;
743 }
744 mutex_lock_nested(&newcon->sock_mutex, 1);
745 if (newcon->sock) {
746 struct connection *othercon = newcon->othercon;
747
748 if (!othercon) {
David Teigland748285c2009-05-15 10:50:57 -0500749 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100750 if (!othercon) {
David Teigland617e82e2007-04-26 13:46:49 -0500751 log_print("failed to allocate incoming socket");
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100752 mutex_unlock(&newcon->sock_mutex);
753 result = -ENOMEM;
754 goto accept_err;
755 }
756 othercon->nodeid = nodeid;
757 othercon->rx_action = receive_from_sock;
758 mutex_init(&othercon->sock_mutex);
759 INIT_WORK(&othercon->swork, process_send_sockets);
760 INIT_WORK(&othercon->rwork, process_recv_sockets);
761 set_bit(CF_IS_OTHERCON, &othercon->flags);
Patrick Caulfield61d96be2007-08-20 15:13:38 +0100762 }
763 if (!othercon->sock) {
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100764 newcon->othercon = othercon;
Patrick Caulfield97d84832007-06-27 11:36:23 +0100765 othercon->sock = newsock;
766 newsock->sk->sk_user_data = othercon;
767 add_sock(newsock, othercon);
768 addcon = othercon;
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100769 }
Patrick Caulfield97d84832007-06-27 11:36:23 +0100770 else {
771 printk("Extra connection from node %d attempted\n", nodeid);
772 result = -EAGAIN;
akpm@linux-foundation.orgf4fadb23c2007-06-27 14:43:37 -0700773 mutex_unlock(&newcon->sock_mutex);
Patrick Caulfield97d84832007-06-27 11:36:23 +0100774 goto accept_err;
775 }
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100776 }
777 else {
778 newsock->sk->sk_user_data = newcon;
779 newcon->rx_action = receive_from_sock;
780 add_sock(newsock, newcon);
781 addcon = newcon;
782 }
783
784 mutex_unlock(&newcon->sock_mutex);
785
786 /*
787 * Add it to the active queue in case we got data
788 * beween processing the accept adding the socket
789 * to the read_sockets list
790 */
791 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
792 queue_work(recv_workqueue, &addcon->rwork);
793 mutex_unlock(&con->sock_mutex);
794
795 return 0;
796
797accept_err:
798 mutex_unlock(&con->sock_mutex);
799 sock_release(newsock);
800
801 if (result != -EAGAIN)
David Teigland617e82e2007-04-26 13:46:49 -0500802 log_print("error accepting connection from node: %d", result);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100803 return result;
804}
805
806static void free_entry(struct writequeue_entry *e)
807{
808 __free_page(e->page);
809 kfree(e);
810}
811
812/* Initiate an SCTP association.
813 This is a special case of send_to_sock() in that we don't yet have a
814 peeled-off socket for this association, so we use the listening socket
815 and add the primary IP address of the remote node.
816 */
817static void sctp_init_assoc(struct connection *con)
818{
819 struct sockaddr_storage rem_addr;
820 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
821 struct msghdr outmessage;
822 struct cmsghdr *cmsg;
823 struct sctp_sndrcvinfo *sinfo;
824 struct connection *base_con;
825 struct writequeue_entry *e;
826 int len, offset;
827 int ret;
828 int addrlen;
829 struct kvec iov[1];
830
831 if (test_and_set_bit(CF_INIT_PENDING, &con->flags))
832 return;
833
834 if (con->retries++ > MAX_CONNECT_RETRIES)
835 return;
836
837 log_print("Initiating association with node %d", con->nodeid);
838
839 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) {
840 log_print("no address for nodeid %d", con->nodeid);
841 return;
842 }
843 base_con = nodeid2con(0, 0);
844 BUG_ON(base_con == NULL);
845
846 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen);
847
848 outmessage.msg_name = &rem_addr;
849 outmessage.msg_namelen = addrlen;
850 outmessage.msg_control = outcmsg;
851 outmessage.msg_controllen = sizeof(outcmsg);
852 outmessage.msg_flags = MSG_EOR;
853
854 spin_lock(&con->writequeue_lock);
855 e = list_entry(con->writequeue.next, struct writequeue_entry,
856 list);
857
858 BUG_ON((struct list_head *) e == &con->writequeue);
859
860 len = e->len;
861 offset = e->offset;
862 spin_unlock(&con->writequeue_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100863
864 /* Send the first block off the write queue */
865 iov[0].iov_base = page_address(e->page)+offset;
866 iov[0].iov_len = len;
867
868 cmsg = CMSG_FIRSTHDR(&outmessage);
869 cmsg->cmsg_level = IPPROTO_SCTP;
870 cmsg->cmsg_type = SCTP_SNDRCV;
871 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
872 sinfo = CMSG_DATA(cmsg);
873 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
874 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid());
875 outmessage.msg_controllen = cmsg->cmsg_len;
876
877 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len);
878 if (ret < 0) {
David Teigland617e82e2007-04-26 13:46:49 -0500879 log_print("Send first packet to node %d failed: %d",
880 con->nodeid, ret);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100881
882 /* Try again later */
883 clear_bit(CF_CONNECT_PENDING, &con->flags);
884 clear_bit(CF_INIT_PENDING, &con->flags);
885 }
886 else {
887 spin_lock(&con->writequeue_lock);
888 e->offset += ret;
889 e->len -= ret;
890
891 if (e->len == 0 && e->users == 0) {
892 list_del(&e->list);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100893 free_entry(e);
894 }
895 spin_unlock(&con->writequeue_lock);
896 }
897}
898
899/* Connect a new socket to its peer */
900static void tcp_connect_to_sock(struct connection *con)
901{
902 int result = -EHOSTUNREACH;
Lon Hohberger6bd8fed2007-10-25 18:51:54 -0400903 struct sockaddr_storage saddr, src_addr;
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100904 int addr_len;
905 struct socket *sock;
906
907 if (con->nodeid == 0) {
908 log_print("attempt to connect sock 0 foiled");
909 return;
910 }
911
912 mutex_lock(&con->sock_mutex);
913 if (con->retries++ > MAX_CONNECT_RETRIES)
914 goto out;
915
916 /* Some odd races can cause double-connects, ignore them */
917 if (con->sock) {
918 result = 0;
919 goto out;
920 }
921
922 /* Create a socket to communicate with */
923 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
924 IPPROTO_TCP, &sock);
925 if (result < 0)
926 goto out_err;
927
928 memset(&saddr, 0, sizeof(saddr));
Masatake YAMATO311f6fc2008-06-27 08:35:03 -0500929 if (dlm_nodeid_to_addr(con->nodeid, &saddr)) {
930 sock_release(sock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100931 goto out_err;
Masatake YAMATO311f6fc2008-06-27 08:35:03 -0500932 }
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100933
934 sock->sk->sk_user_data = con;
935 con->rx_action = receive_from_sock;
936 con->connect_action = tcp_connect_to_sock;
937 add_sock(sock, con);
938
Lon Hohberger6bd8fed2007-10-25 18:51:54 -0400939 /* Bind to our cluster-known address connecting to avoid
940 routing problems */
941 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr));
942 make_sockaddr(&src_addr, 0, &addr_len);
943 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr,
944 addr_len);
945 if (result < 0) {
946 log_print("could not bind for connect: %d", result);
947 /* This *may* not indicate a critical error */
948 }
949
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100950 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
951
952 log_print("connecting to %d", con->nodeid);
953 result =
954 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
955 O_NONBLOCK);
956 if (result == -EINPROGRESS)
957 result = 0;
958 if (result == 0)
959 goto out;
960
961out_err:
962 if (con->sock) {
963 sock_release(con->sock);
964 con->sock = NULL;
965 }
966 /*
967 * Some errors are fatal and this list might need adjusting. For other
968 * errors we try again until the max number of retries is reached.
969 */
970 if (result != -EHOSTUNREACH && result != -ENETUNREACH &&
Marcin Slusarz0035a4b2008-05-11 22:01:29 +0200971 result != -ENETDOWN && result != -EINVAL
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100972 && result != -EPROTONOSUPPORT) {
973 lowcomms_connect_sock(con);
974 result = 0;
975 }
976out:
977 mutex_unlock(&con->sock_mutex);
978 return;
979}
980
981static struct socket *tcp_create_listen_sock(struct connection *con,
982 struct sockaddr_storage *saddr)
983{
984 struct socket *sock = NULL;
985 int result = 0;
986 int one = 1;
987 int addr_len;
988
989 if (dlm_local_addr[0]->ss_family == AF_INET)
990 addr_len = sizeof(struct sockaddr_in);
991 else
992 addr_len = sizeof(struct sockaddr_in6);
993
994 /* Create a socket to communicate with */
David Teigland617e82e2007-04-26 13:46:49 -0500995 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
996 IPPROTO_TCP, &sock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100997 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -0500998 log_print("Can't create listening comms socket");
Patrick Caulfield6ed72572007-04-17 15:39:57 +0100999 goto create_out;
1000 }
1001
1002 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
1003 (char *)&one, sizeof(one));
1004
1005 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001006 log_print("Failed to set SO_REUSEADDR on socket: %d", result);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001007 }
1008 sock->sk->sk_user_data = con;
1009 con->rx_action = tcp_accept_from_sock;
1010 con->connect_action = tcp_connect_to_sock;
1011 con->sock = sock;
1012
1013 /* Bind to our port */
1014 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
1015 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
1016 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001017 log_print("Can't bind to port %d", dlm_config.ci_tcp_port);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001018 sock_release(sock);
1019 sock = NULL;
1020 con->sock = NULL;
1021 goto create_out;
1022 }
1023 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
1024 (char *)&one, sizeof(one));
1025 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001026 log_print("Set keepalive failed: %d", result);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001027 }
1028
1029 result = sock->ops->listen(sock, 5);
1030 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001031 log_print("Can't listen on port %d", dlm_config.ci_tcp_port);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001032 sock_release(sock);
1033 sock = NULL;
1034 goto create_out;
1035 }
1036
1037create_out:
1038 return sock;
1039}
1040
1041/* Get local addresses */
1042static void init_local(void)
1043{
1044 struct sockaddr_storage sas, *addr;
1045 int i;
1046
Patrick Caulfield30d3a232007-04-23 16:26:21 +01001047 dlm_local_count = 0;
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001048 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
1049 if (dlm_our_addr(&sas, i))
1050 break;
1051
1052 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1053 if (!addr)
1054 break;
1055 memcpy(addr, &sas, sizeof(*addr));
1056 dlm_local_addr[dlm_local_count++] = addr;
1057 }
1058}
1059
David Teigland617e82e2007-04-26 13:46:49 -05001060/* Bind to an IP address. SCTP allows multiple address so it can do
1061 multi-homing */
1062static int add_sctp_bind_addr(struct connection *sctp_con,
1063 struct sockaddr_storage *addr,
1064 int addr_len, int num)
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001065{
1066 int result = 0;
1067
1068 if (num == 1)
1069 result = kernel_bind(sctp_con->sock,
1070 (struct sockaddr *) addr,
1071 addr_len);
1072 else
1073 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP,
1074 SCTP_SOCKOPT_BINDX_ADD,
1075 (char *)addr, addr_len);
1076
1077 if (result < 0)
1078 log_print("Can't bind to port %d addr number %d",
1079 dlm_config.ci_tcp_port, num);
1080
1081 return result;
1082}
1083
1084/* Initialise SCTP socket and bind to all interfaces */
1085static int sctp_listen_for_all(void)
1086{
1087 struct socket *sock = NULL;
1088 struct sockaddr_storage localaddr;
1089 struct sctp_event_subscribe subscribe;
1090 int result = -EINVAL, num = 1, i, addr_len;
1091 struct connection *con = nodeid2con(0, GFP_KERNEL);
1092 int bufsize = NEEDED_RMEM;
1093
1094 if (!con)
1095 return -ENOMEM;
1096
1097 log_print("Using SCTP for communications");
1098
1099 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
1100 IPPROTO_SCTP, &sock);
1101 if (result < 0) {
1102 log_print("Can't create comms socket, check SCTP is loaded");
1103 goto out;
1104 }
1105
1106 /* Listen for events */
1107 memset(&subscribe, 0, sizeof(subscribe));
1108 subscribe.sctp_data_io_event = 1;
1109 subscribe.sctp_association_event = 1;
1110 subscribe.sctp_send_failure_event = 1;
1111 subscribe.sctp_shutdown_event = 1;
1112 subscribe.sctp_partial_delivery_event = 1;
1113
David S. Millerdf61c952007-11-06 23:48:57 -08001114 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE,
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001115 (char *)&bufsize, sizeof(bufsize));
1116 if (result)
David Teigland617e82e2007-04-26 13:46:49 -05001117 log_print("Error increasing buffer space on socket %d", result);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001118
1119 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
David Teigland617e82e2007-04-26 13:46:49 -05001120 (char *)&subscribe, sizeof(subscribe));
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001121 if (result < 0) {
1122 log_print("Failed to set SCTP_EVENTS on socket: result=%d",
1123 result);
1124 goto create_delsock;
1125 }
1126
1127 /* Init con struct */
1128 sock->sk->sk_user_data = con;
1129 con->sock = sock;
1130 con->sock->sk->sk_data_ready = lowcomms_data_ready;
1131 con->rx_action = receive_from_sock;
1132 con->connect_action = sctp_init_assoc;
1133
1134 /* Bind to all interfaces. */
1135 for (i = 0; i < dlm_local_count; i++) {
1136 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
1137 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len);
1138
1139 result = add_sctp_bind_addr(con, &localaddr, addr_len, num);
1140 if (result)
1141 goto create_delsock;
1142 ++num;
1143 }
1144
1145 result = sock->ops->listen(sock, 5);
1146 if (result < 0) {
1147 log_print("Can't set socket listening");
1148 goto create_delsock;
1149 }
1150
1151 return 0;
1152
1153create_delsock:
1154 sock_release(sock);
1155 con->sock = NULL;
1156out:
1157 return result;
1158}
1159
1160static int tcp_listen_for_all(void)
1161{
1162 struct socket *sock = NULL;
1163 struct connection *con = nodeid2con(0, GFP_KERNEL);
1164 int result = -EINVAL;
1165
1166 if (!con)
1167 return -ENOMEM;
1168
1169 /* We don't support multi-homed hosts */
1170 if (dlm_local_addr[1] != NULL) {
David Teigland617e82e2007-04-26 13:46:49 -05001171 log_print("TCP protocol can't handle multi-homed hosts, "
1172 "try SCTP");
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001173 return -EINVAL;
1174 }
1175
1176 log_print("Using TCP for communications");
1177
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001178 sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
1179 if (sock) {
1180 add_sock(sock, con);
1181 result = 0;
1182 }
1183 else {
1184 result = -EADDRINUSE;
1185 }
1186
1187 return result;
1188}
1189
1190
1191
1192static struct writequeue_entry *new_writequeue_entry(struct connection *con,
1193 gfp_t allocation)
1194{
1195 struct writequeue_entry *entry;
1196
1197 entry = kmalloc(sizeof(struct writequeue_entry), allocation);
1198 if (!entry)
1199 return NULL;
1200
1201 entry->page = alloc_page(allocation);
1202 if (!entry->page) {
1203 kfree(entry);
1204 return NULL;
1205 }
1206
1207 entry->offset = 0;
1208 entry->len = 0;
1209 entry->end = 0;
1210 entry->users = 0;
1211 entry->con = con;
1212
1213 return entry;
1214}
1215
David Teigland617e82e2007-04-26 13:46:49 -05001216void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001217{
1218 struct connection *con;
1219 struct writequeue_entry *e;
1220 int offset = 0;
1221 int users = 0;
1222
1223 con = nodeid2con(nodeid, allocation);
1224 if (!con)
1225 return NULL;
1226
1227 spin_lock(&con->writequeue_lock);
1228 e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
1229 if ((&e->list == &con->writequeue) ||
1230 (PAGE_CACHE_SIZE - e->end < len)) {
1231 e = NULL;
1232 } else {
1233 offset = e->end;
1234 e->end += len;
1235 users = e->users++;
1236 }
1237 spin_unlock(&con->writequeue_lock);
1238
1239 if (e) {
1240 got_one:
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001241 *ppc = page_address(e->page) + offset;
1242 return e;
1243 }
1244
1245 e = new_writequeue_entry(con, allocation);
1246 if (e) {
1247 spin_lock(&con->writequeue_lock);
1248 offset = e->end;
1249 e->end += len;
1250 users = e->users++;
1251 list_add_tail(&e->list, &con->writequeue);
1252 spin_unlock(&con->writequeue_lock);
1253 goto got_one;
1254 }
1255 return NULL;
1256}
1257
1258void dlm_lowcomms_commit_buffer(void *mh)
1259{
1260 struct writequeue_entry *e = (struct writequeue_entry *)mh;
1261 struct connection *con = e->con;
1262 int users;
1263
1264 spin_lock(&con->writequeue_lock);
1265 users = --e->users;
1266 if (users)
1267 goto out;
1268 e->len = e->end - e->offset;
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001269 spin_unlock(&con->writequeue_lock);
1270
1271 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
1272 queue_work(send_workqueue, &con->swork);
1273 }
1274 return;
1275
1276out:
1277 spin_unlock(&con->writequeue_lock);
1278 return;
1279}
1280
1281/* Send a message */
1282static void send_to_sock(struct connection *con)
1283{
1284 int ret = 0;
1285 ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int);
1286 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1287 struct writequeue_entry *e;
1288 int len, offset;
1289
1290 mutex_lock(&con->sock_mutex);
1291 if (con->sock == NULL)
1292 goto out_connect;
1293
1294 sendpage = con->sock->ops->sendpage;
1295
1296 spin_lock(&con->writequeue_lock);
1297 for (;;) {
1298 e = list_entry(con->writequeue.next, struct writequeue_entry,
1299 list);
1300 if ((struct list_head *) e == &con->writequeue)
1301 break;
1302
1303 len = e->len;
1304 offset = e->offset;
1305 BUG_ON(len == 0 && e->users == 0);
1306 spin_unlock(&con->writequeue_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001307
1308 ret = 0;
1309 if (len) {
1310 ret = sendpage(con->sock, e->page, offset, len,
1311 msg_flags);
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001312 if (ret == -EAGAIN || ret == 0) {
1313 cond_resched();
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001314 goto out;
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001315 }
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001316 if (ret <= 0)
1317 goto send_error;
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001318 }
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001319 /* Don't starve people filling buffers */
1320 cond_resched();
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001321
1322 spin_lock(&con->writequeue_lock);
1323 e->offset += ret;
1324 e->len -= ret;
1325
1326 if (e->len == 0 && e->users == 0) {
1327 list_del(&e->list);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001328 free_entry(e);
1329 continue;
1330 }
1331 }
1332 spin_unlock(&con->writequeue_lock);
1333out:
1334 mutex_unlock(&con->sock_mutex);
1335 return;
1336
1337send_error:
1338 mutex_unlock(&con->sock_mutex);
1339 close_connection(con, false);
1340 lowcomms_connect_sock(con);
1341 return;
1342
1343out_connect:
1344 mutex_unlock(&con->sock_mutex);
1345 if (!test_bit(CF_INIT_PENDING, &con->flags))
1346 lowcomms_connect_sock(con);
1347 return;
1348}
1349
1350static void clean_one_writequeue(struct connection *con)
1351{
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001352 struct writequeue_entry *e, *safe;
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001353
1354 spin_lock(&con->writequeue_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001355 list_for_each_entry_safe(e, safe, &con->writequeue, list) {
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001356 list_del(&e->list);
1357 free_entry(e);
1358 }
1359 spin_unlock(&con->writequeue_lock);
1360}
1361
1362/* Called from recovery when it knows that a node has
1363 left the cluster */
1364int dlm_lowcomms_close(int nodeid)
1365{
1366 struct connection *con;
1367
1368 log_print("closing connection to node %d", nodeid);
1369 con = nodeid2con(nodeid, 0);
1370 if (con) {
1371 clean_one_writequeue(con);
1372 close_connection(con, true);
1373 }
1374 return 0;
1375}
1376
1377/* Receive workqueue function */
1378static void process_recv_sockets(struct work_struct *work)
1379{
1380 struct connection *con = container_of(work, struct connection, rwork);
1381 int err;
1382
1383 clear_bit(CF_READ_PENDING, &con->flags);
1384 do {
1385 err = con->rx_action(con);
1386 } while (!err);
1387}
1388
1389/* Send workqueue function */
1390static void process_send_sockets(struct work_struct *work)
1391{
1392 struct connection *con = container_of(work, struct connection, swork);
1393
1394 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
1395 con->connect_action(con);
1396 }
1397 clear_bit(CF_WRITE_PENDING, &con->flags);
1398 send_to_sock(con);
1399}
1400
1401
1402/* Discard all entries on the write queues */
1403static void clean_writequeues(void)
1404{
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001405 foreach_conn(clean_one_writequeue);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001406}
1407
1408static void work_stop(void)
1409{
1410 destroy_workqueue(recv_workqueue);
1411 destroy_workqueue(send_workqueue);
1412}
1413
1414static int work_start(void)
1415{
1416 int error;
1417 recv_workqueue = create_workqueue("dlm_recv");
1418 error = IS_ERR(recv_workqueue);
1419 if (error) {
1420 log_print("can't start dlm_recv %d", error);
1421 return error;
1422 }
1423
1424 send_workqueue = create_singlethread_workqueue("dlm_send");
1425 error = IS_ERR(send_workqueue);
1426 if (error) {
1427 log_print("can't start dlm_send %d", error);
1428 destroy_workqueue(recv_workqueue);
1429 return error;
1430 }
1431
1432 return 0;
1433}
1434
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001435static void stop_conn(struct connection *con)
1436{
1437 con->flags |= 0x0F;
Christine Caulfield391fbdc2009-05-07 10:54:16 -05001438 if (con->sock && con->sock->sk)
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001439 con->sock->sk->sk_user_data = NULL;
1440}
1441
1442static void free_conn(struct connection *con)
1443{
1444 close_connection(con, true);
1445 if (con->othercon)
1446 kmem_cache_free(con_cache, con->othercon);
1447 hlist_del(&con->list);
1448 kmem_cache_free(con_cache, con);
1449}
1450
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001451void dlm_lowcomms_stop(void)
1452{
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001453 /* Set all the flags to prevent any
1454 socket activity.
1455 */
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001456 mutex_lock(&connections_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001457 foreach_conn(stop_conn);
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001458 mutex_unlock(&connections_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001459
1460 work_stop();
1461
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001462 mutex_lock(&connections_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001463 clean_writequeues();
1464
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001465 foreach_conn(free_conn);
1466
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001467 mutex_unlock(&connections_lock);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001468 kmem_cache_destroy(con_cache);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001469}
1470
1471int dlm_lowcomms_start(void)
1472{
1473 int error = -EINVAL;
1474 struct connection *con;
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001475 int i;
1476
1477 for (i = 0; i < CONN_HASH_SIZE; i++)
1478 INIT_HLIST_HEAD(&connection_hash[i]);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001479
1480 init_local();
1481 if (!dlm_local_count) {
David Teigland617e82e2007-04-26 13:46:49 -05001482 error = -ENOTCONN;
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001483 log_print("no local IP address has been set");
1484 goto out;
1485 }
1486
1487 error = -ENOMEM;
1488 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
1489 __alignof__(struct connection), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001490 NULL);
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001491 if (!con_cache)
1492 goto out;
1493
Patrick Caulfield6ed72572007-04-17 15:39:57 +01001494 /* Start listening */
1495 if (dlm_config.ci_protocol == 0)
1496 error = tcp_listen_for_all();
1497 else
1498 error = sctp_listen_for_all();
1499 if (error)
1500 goto fail_unlisten;
1501
1502 error = work_start();
1503 if (error)
1504 goto fail_unlisten;
1505
1506 return 0;
1507
1508fail_unlisten:
1509 con = nodeid2con(0,0);
1510 if (con) {
1511 close_connection(con, false);
1512 kmem_cache_free(con_cache, con);
1513 }
1514 kmem_cache_destroy(con_cache);
1515
1516out:
1517 return error;
1518}