blob: 609108a83267f3cfffd9d539f29496c0e5ffc1b1 [file] [log] [blame]
Patrick Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 15:39:57 +010051#include <linux/file.h>
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -050052#include <linux/mutex.h>
Patrick Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 15:39:57 +0100182
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600183 con = __find_con(nodeid);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100184 if (con || !alloc)
185 return con;
186
Patrick Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 15:39:57 +0100232 con = __nodeid2con(nodeid, allocation);
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500233 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 15:39:57 +0100253 }
254 }
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500255 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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 Caulfield6ed7257b2007-04-17 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
312/* Make a socket active */
313static int add_sock(struct socket *sock, struct connection *con)
314{
315 con->sock = sock;
316
317 /* Install a data_ready callback */
318 con->sock->sk->sk_data_ready = lowcomms_data_ready;
319 con->sock->sk->sk_write_space = lowcomms_write_space;
320 con->sock->sk->sk_state_change = lowcomms_state_change;
321 con->sock->sk->sk_user_data = con;
Steven Whitehoused6d7b702008-11-12 16:49:48 -0600322 con->sock->sk->sk_allocation = GFP_NOFS;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100323 return 0;
324}
325
326/* Add the port number to an IPv6 or 4 sockaddr and return the address
327 length */
328static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
329 int *addr_len)
330{
331 saddr->ss_family = dlm_local_addr[0]->ss_family;
332 if (saddr->ss_family == AF_INET) {
333 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
334 in4_addr->sin_port = cpu_to_be16(port);
335 *addr_len = sizeof(struct sockaddr_in);
336 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
337 } else {
338 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
339 in6_addr->sin6_port = cpu_to_be16(port);
340 *addr_len = sizeof(struct sockaddr_in6);
341 }
Patrick Caulfield01c8cab2007-07-17 16:53:15 +0100342 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100343}
344
345/* Close a remote connection and tidy up */
346static void close_connection(struct connection *con, bool and_other)
347{
348 mutex_lock(&con->sock_mutex);
349
350 if (con->sock) {
351 sock_release(con->sock);
352 con->sock = NULL;
353 }
354 if (con->othercon && and_other) {
355 /* Will only re-enter once. */
356 close_connection(con->othercon, false);
357 }
358 if (con->rx_page) {
359 __free_page(con->rx_page);
360 con->rx_page = NULL;
361 }
Patrick Caulfield9e5f2822007-08-02 14:58:14 +0100362
Patrick Caulfield61d96be2007-08-20 15:13:38 +0100363 con->retries = 0;
364 mutex_unlock(&con->sock_mutex);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100365}
366
367/* We only send shutdown messages to nodes that are not part of the cluster */
368static void sctp_send_shutdown(sctp_assoc_t associd)
369{
370 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
371 struct msghdr outmessage;
372 struct cmsghdr *cmsg;
373 struct sctp_sndrcvinfo *sinfo;
374 int ret;
375 struct connection *con;
376
377 con = nodeid2con(0,0);
378 BUG_ON(con == NULL);
379
380 outmessage.msg_name = NULL;
381 outmessage.msg_namelen = 0;
382 outmessage.msg_control = outcmsg;
383 outmessage.msg_controllen = sizeof(outcmsg);
384 outmessage.msg_flags = MSG_EOR;
385
386 cmsg = CMSG_FIRSTHDR(&outmessage);
387 cmsg->cmsg_level = IPPROTO_SCTP;
388 cmsg->cmsg_type = SCTP_SNDRCV;
389 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
390 outmessage.msg_controllen = cmsg->cmsg_len;
391 sinfo = CMSG_DATA(cmsg);
392 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
393
394 sinfo->sinfo_flags |= MSG_EOF;
395 sinfo->sinfo_assoc_id = associd;
396
397 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0);
398
399 if (ret != 0)
400 log_print("send EOF to node failed: %d", ret);
401}
402
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600403static void sctp_init_failed_foreach(struct connection *con)
404{
405 con->sctp_assoc = 0;
406 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
407 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
408 queue_work(send_workqueue, &con->swork);
409 }
410}
411
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100412/* INIT failed but we don't know which node...
413 restart INIT on all pending nodes */
414static void sctp_init_failed(void)
415{
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500416 mutex_lock(&connections_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600417
418 foreach_conn(sctp_init_failed_foreach);
419
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500420 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100421}
422
423/* Something happened to an association */
David Teigland617e82e2007-04-26 13:46:49 -0500424static void process_sctp_notification(struct connection *con,
425 struct msghdr *msg, char *buf)
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100426{
427 union sctp_notification *sn = (union sctp_notification *)buf;
428
429 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
430 switch (sn->sn_assoc_change.sac_state) {
431
432 case SCTP_COMM_UP:
433 case SCTP_RESTART:
434 {
435 /* Check that the new node is in the lockspace */
436 struct sctp_prim prim;
437 int nodeid;
438 int prim_len, ret;
439 int addr_len;
440 struct connection *new_con;
441 struct file *file;
442 sctp_peeloff_arg_t parg;
443 int parglen = sizeof(parg);
444
445 /*
446 * We get this before any data for an association.
447 * We verify that the node is in the cluster and
448 * then peel off a socket for it.
449 */
450 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
451 log_print("COMM_UP for invalid assoc ID %d",
David Teigland617e82e2007-04-26 13:46:49 -0500452 (int)sn->sn_assoc_change.sac_assoc_id);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100453 sctp_init_failed();
454 return;
455 }
456 memset(&prim, 0, sizeof(struct sctp_prim));
457 prim_len = sizeof(struct sctp_prim);
458 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
459
460 ret = kernel_getsockopt(con->sock,
461 IPPROTO_SCTP,
462 SCTP_PRIMARY_ADDR,
463 (char*)&prim,
464 &prim_len);
465 if (ret < 0) {
466 log_print("getsockopt/sctp_primary_addr on "
467 "new assoc %d failed : %d",
468 (int)sn->sn_assoc_change.sac_assoc_id,
469 ret);
470
471 /* Retry INIT later */
472 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
473 if (new_con)
474 clear_bit(CF_CONNECT_PENDING, &con->flags);
475 return;
476 }
477 make_sockaddr(&prim.ssp_addr, 0, &addr_len);
478 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
479 int i;
480 unsigned char *b=(unsigned char *)&prim.ssp_addr;
481 log_print("reject connect from unknown addr");
482 for (i=0; i<sizeof(struct sockaddr_storage);i++)
483 printk("%02x ", b[i]);
484 printk("\n");
485 sctp_send_shutdown(prim.ssp_assoc_id);
486 return;
487 }
488
489 new_con = nodeid2con(nodeid, GFP_KERNEL);
490 if (!new_con)
491 return;
492
493 /* Peel off a new sock */
494 parg.associd = sn->sn_assoc_change.sac_assoc_id;
David Teigland617e82e2007-04-26 13:46:49 -0500495 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP,
496 SCTP_SOCKOPT_PEELOFF,
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100497 (void *)&parg, &parglen);
Patrick Caulfield30d3a232007-04-23 16:26:21 +0100498 if (ret) {
David Teigland617e82e2007-04-26 13:46:49 -0500499 log_print("Can't peel off a socket for "
500 "connection %d to node %d: err=%d\n",
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100501 parg.associd, nodeid, ret);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100502 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100503 file = fget(parg.sd);
504 new_con->sock = SOCKET_I(file->f_dentry->d_inode);
505 add_sock(new_con->sock, new_con);
506 fput(file);
507 put_unused_fd(parg.sd);
508
509 log_print("got new/restarted association %d nodeid %d",
David Teigland617e82e2007-04-26 13:46:49 -0500510 (int)sn->sn_assoc_change.sac_assoc_id, nodeid);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100511
512 /* Send any pending writes */
513 clear_bit(CF_CONNECT_PENDING, &new_con->flags);
514 clear_bit(CF_INIT_PENDING, &con->flags);
515 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) {
516 queue_work(send_workqueue, &new_con->swork);
517 }
518 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags))
519 queue_work(recv_workqueue, &new_con->rwork);
520 }
521 break;
522
523 case SCTP_COMM_LOST:
524 case SCTP_SHUTDOWN_COMP:
525 {
526 con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
527 if (con) {
528 con->sctp_assoc = 0;
529 }
530 }
531 break;
532
533 /* We don't know which INIT failed, so clear the PENDING flags
534 * on them all. if assoc_id is zero then it will then try
535 * again */
536
537 case SCTP_CANT_STR_ASSOC:
538 {
539 log_print("Can't start SCTP association - retrying");
540 sctp_init_failed();
541 }
542 break;
543
544 default:
545 log_print("unexpected SCTP assoc change id=%d state=%d",
546 (int)sn->sn_assoc_change.sac_assoc_id,
547 sn->sn_assoc_change.sac_state);
548 }
549 }
550}
551
552/* Data received from remote end */
553static int receive_from_sock(struct connection *con)
554{
555 int ret = 0;
556 struct msghdr msg = {};
557 struct kvec iov[2];
558 unsigned len;
559 int r;
560 int call_again_soon = 0;
561 int nvec;
562 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
563
564 mutex_lock(&con->sock_mutex);
565
566 if (con->sock == NULL) {
567 ret = -EAGAIN;
568 goto out_close;
569 }
570
571 if (con->rx_page == NULL) {
572 /*
573 * This doesn't need to be atomic, but I think it should
574 * improve performance if it is.
575 */
576 con->rx_page = alloc_page(GFP_ATOMIC);
577 if (con->rx_page == NULL)
578 goto out_resched;
579 cbuf_init(&con->cb, PAGE_CACHE_SIZE);
580 }
581
582 /* Only SCTP needs these really */
583 memset(&incmsg, 0, sizeof(incmsg));
584 msg.msg_control = incmsg;
585 msg.msg_controllen = sizeof(incmsg);
586
587 /*
588 * iov[0] is the bit of the circular buffer between the current end
589 * point (cb.base + cb.len) and the end of the buffer.
590 */
591 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
592 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
593 iov[1].iov_len = 0;
594 nvec = 1;
595
596 /*
597 * iov[1] is the bit of the circular buffer between the start of the
598 * buffer and the start of the currently used section (cb.base)
599 */
600 if (cbuf_data(&con->cb) >= con->cb.base) {
601 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);
602 iov[1].iov_len = con->cb.base;
603 iov[1].iov_base = page_address(con->rx_page);
604 nvec = 2;
605 }
606 len = iov[0].iov_len + iov[1].iov_len;
607
608 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
609 MSG_DONTWAIT | MSG_NOSIGNAL);
610 if (ret <= 0)
611 goto out_close;
612
613 /* Process SCTP notifications */
614 if (msg.msg_flags & MSG_NOTIFICATION) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100615 msg.msg_control = incmsg;
616 msg.msg_controllen = sizeof(incmsg);
617
618 process_sctp_notification(con, &msg,
David Teigland617e82e2007-04-26 13:46:49 -0500619 page_address(con->rx_page) + con->cb.base);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100620 mutex_unlock(&con->sock_mutex);
621 return 0;
622 }
623 BUG_ON(con->nodeid == 0);
624
625 if (ret == len)
626 call_again_soon = 1;
627 cbuf_add(&con->cb, ret);
628 ret = dlm_process_incoming_buffer(con->nodeid,
629 page_address(con->rx_page),
630 con->cb.base, con->cb.len,
631 PAGE_CACHE_SIZE);
632 if (ret == -EBADMSG) {
David Teigland617e82e2007-04-26 13:46:49 -0500633 log_print("lowcomms: addr=%p, base=%u, len=%u, "
634 "iov_len=%u, iov_base[0]=%p, read=%d",
635 page_address(con->rx_page), con->cb.base, con->cb.len,
636 len, iov[0].iov_base, r);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100637 }
638 if (ret < 0)
639 goto out_close;
640 cbuf_eat(&con->cb, ret);
641
642 if (cbuf_empty(&con->cb) && !call_again_soon) {
643 __free_page(con->rx_page);
644 con->rx_page = NULL;
645 }
646
647 if (call_again_soon)
648 goto out_resched;
649 mutex_unlock(&con->sock_mutex);
650 return 0;
651
652out_resched:
653 if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
654 queue_work(recv_workqueue, &con->rwork);
655 mutex_unlock(&con->sock_mutex);
656 return -EAGAIN;
657
658out_close:
659 mutex_unlock(&con->sock_mutex);
Patrick Caulfield9e5f2822007-08-02 14:58:14 +0100660 if (ret != -EAGAIN) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100661 close_connection(con, false);
662 /* Reconnect when there is something to send */
663 }
664 /* Don't return success if we really got EOF */
665 if (ret == 0)
666 ret = -EAGAIN;
667
668 return ret;
669}
670
671/* Listening socket is busy, accept a connection */
672static int tcp_accept_from_sock(struct connection *con)
673{
674 int result;
675 struct sockaddr_storage peeraddr;
676 struct socket *newsock;
677 int len;
678 int nodeid;
679 struct connection *newcon;
680 struct connection *addcon;
681
682 memset(&peeraddr, 0, sizeof(peeraddr));
683 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
684 IPPROTO_TCP, &newsock);
685 if (result < 0)
686 return -ENOMEM;
687
688 mutex_lock_nested(&con->sock_mutex, 0);
689
690 result = -ENOTCONN;
691 if (con->sock == NULL)
692 goto accept_err;
693
694 newsock->type = con->sock->type;
695 newsock->ops = con->sock->ops;
696
697 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
698 if (result < 0)
699 goto accept_err;
700
701 /* Get the connected socket's peer */
702 memset(&peeraddr, 0, sizeof(peeraddr));
703 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
704 &len, 2)) {
705 result = -ECONNABORTED;
706 goto accept_err;
707 }
708
709 /* Get the new node's NODEID */
710 make_sockaddr(&peeraddr, 0, &len);
711 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
David Teigland617e82e2007-04-26 13:46:49 -0500712 log_print("connect from non cluster node");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100713 sock_release(newsock);
714 mutex_unlock(&con->sock_mutex);
715 return -1;
716 }
717
718 log_print("got connection from %d", nodeid);
719
720 /* Check to see if we already have a connection to this node. This
721 * could happen if the two nodes initiate a connection at roughly
722 * the same time and the connections cross on the wire.
723 * In this case we store the incoming one in "othercon"
724 */
725 newcon = nodeid2con(nodeid, GFP_KERNEL);
726 if (!newcon) {
727 result = -ENOMEM;
728 goto accept_err;
729 }
730 mutex_lock_nested(&newcon->sock_mutex, 1);
731 if (newcon->sock) {
732 struct connection *othercon = newcon->othercon;
733
734 if (!othercon) {
735 othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL);
736 if (!othercon) {
David Teigland617e82e2007-04-26 13:46:49 -0500737 log_print("failed to allocate incoming socket");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100738 mutex_unlock(&newcon->sock_mutex);
739 result = -ENOMEM;
740 goto accept_err;
741 }
742 othercon->nodeid = nodeid;
743 othercon->rx_action = receive_from_sock;
744 mutex_init(&othercon->sock_mutex);
745 INIT_WORK(&othercon->swork, process_send_sockets);
746 INIT_WORK(&othercon->rwork, process_recv_sockets);
747 set_bit(CF_IS_OTHERCON, &othercon->flags);
Patrick Caulfield61d96be2007-08-20 15:13:38 +0100748 }
749 if (!othercon->sock) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100750 newcon->othercon = othercon;
Patrick Caulfield97d84832007-06-27 11:36:23 +0100751 othercon->sock = newsock;
752 newsock->sk->sk_user_data = othercon;
753 add_sock(newsock, othercon);
754 addcon = othercon;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100755 }
Patrick Caulfield97d84832007-06-27 11:36:23 +0100756 else {
757 printk("Extra connection from node %d attempted\n", nodeid);
758 result = -EAGAIN;
akpm@linux-foundation.orgf4fadb23c2007-06-27 14:43:37 -0700759 mutex_unlock(&newcon->sock_mutex);
Patrick Caulfield97d84832007-06-27 11:36:23 +0100760 goto accept_err;
761 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100762 }
763 else {
764 newsock->sk->sk_user_data = newcon;
765 newcon->rx_action = receive_from_sock;
766 add_sock(newsock, newcon);
767 addcon = newcon;
768 }
769
770 mutex_unlock(&newcon->sock_mutex);
771
772 /*
773 * Add it to the active queue in case we got data
774 * beween processing the accept adding the socket
775 * to the read_sockets list
776 */
777 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
778 queue_work(recv_workqueue, &addcon->rwork);
779 mutex_unlock(&con->sock_mutex);
780
781 return 0;
782
783accept_err:
784 mutex_unlock(&con->sock_mutex);
785 sock_release(newsock);
786
787 if (result != -EAGAIN)
David Teigland617e82e2007-04-26 13:46:49 -0500788 log_print("error accepting connection from node: %d", result);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100789 return result;
790}
791
792static void free_entry(struct writequeue_entry *e)
793{
794 __free_page(e->page);
795 kfree(e);
796}
797
798/* Initiate an SCTP association.
799 This is a special case of send_to_sock() in that we don't yet have a
800 peeled-off socket for this association, so we use the listening socket
801 and add the primary IP address of the remote node.
802 */
803static void sctp_init_assoc(struct connection *con)
804{
805 struct sockaddr_storage rem_addr;
806 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
807 struct msghdr outmessage;
808 struct cmsghdr *cmsg;
809 struct sctp_sndrcvinfo *sinfo;
810 struct connection *base_con;
811 struct writequeue_entry *e;
812 int len, offset;
813 int ret;
814 int addrlen;
815 struct kvec iov[1];
816
817 if (test_and_set_bit(CF_INIT_PENDING, &con->flags))
818 return;
819
820 if (con->retries++ > MAX_CONNECT_RETRIES)
821 return;
822
823 log_print("Initiating association with node %d", con->nodeid);
824
825 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) {
826 log_print("no address for nodeid %d", con->nodeid);
827 return;
828 }
829 base_con = nodeid2con(0, 0);
830 BUG_ON(base_con == NULL);
831
832 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen);
833
834 outmessage.msg_name = &rem_addr;
835 outmessage.msg_namelen = addrlen;
836 outmessage.msg_control = outcmsg;
837 outmessage.msg_controllen = sizeof(outcmsg);
838 outmessage.msg_flags = MSG_EOR;
839
840 spin_lock(&con->writequeue_lock);
841 e = list_entry(con->writequeue.next, struct writequeue_entry,
842 list);
843
844 BUG_ON((struct list_head *) e == &con->writequeue);
845
846 len = e->len;
847 offset = e->offset;
848 spin_unlock(&con->writequeue_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100849
850 /* Send the first block off the write queue */
851 iov[0].iov_base = page_address(e->page)+offset;
852 iov[0].iov_len = len;
853
854 cmsg = CMSG_FIRSTHDR(&outmessage);
855 cmsg->cmsg_level = IPPROTO_SCTP;
856 cmsg->cmsg_type = SCTP_SNDRCV;
857 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
858 sinfo = CMSG_DATA(cmsg);
859 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
860 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid());
861 outmessage.msg_controllen = cmsg->cmsg_len;
862
863 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len);
864 if (ret < 0) {
David Teigland617e82e2007-04-26 13:46:49 -0500865 log_print("Send first packet to node %d failed: %d",
866 con->nodeid, ret);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100867
868 /* Try again later */
869 clear_bit(CF_CONNECT_PENDING, &con->flags);
870 clear_bit(CF_INIT_PENDING, &con->flags);
871 }
872 else {
873 spin_lock(&con->writequeue_lock);
874 e->offset += ret;
875 e->len -= ret;
876
877 if (e->len == 0 && e->users == 0) {
878 list_del(&e->list);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100879 free_entry(e);
880 }
881 spin_unlock(&con->writequeue_lock);
882 }
883}
884
885/* Connect a new socket to its peer */
886static void tcp_connect_to_sock(struct connection *con)
887{
888 int result = -EHOSTUNREACH;
Lon Hohberger6bd8fed2007-10-25 18:51:54 -0400889 struct sockaddr_storage saddr, src_addr;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100890 int addr_len;
891 struct socket *sock;
892
893 if (con->nodeid == 0) {
894 log_print("attempt to connect sock 0 foiled");
895 return;
896 }
897
898 mutex_lock(&con->sock_mutex);
899 if (con->retries++ > MAX_CONNECT_RETRIES)
900 goto out;
901
902 /* Some odd races can cause double-connects, ignore them */
903 if (con->sock) {
904 result = 0;
905 goto out;
906 }
907
908 /* Create a socket to communicate with */
909 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
910 IPPROTO_TCP, &sock);
911 if (result < 0)
912 goto out_err;
913
914 memset(&saddr, 0, sizeof(saddr));
Masatake YAMATO311f6fc2008-06-27 08:35:03 -0500915 if (dlm_nodeid_to_addr(con->nodeid, &saddr)) {
916 sock_release(sock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100917 goto out_err;
Masatake YAMATO311f6fc2008-06-27 08:35:03 -0500918 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100919
920 sock->sk->sk_user_data = con;
921 con->rx_action = receive_from_sock;
922 con->connect_action = tcp_connect_to_sock;
923 add_sock(sock, con);
924
Lon Hohberger6bd8fed2007-10-25 18:51:54 -0400925 /* Bind to our cluster-known address connecting to avoid
926 routing problems */
927 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr));
928 make_sockaddr(&src_addr, 0, &addr_len);
929 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr,
930 addr_len);
931 if (result < 0) {
932 log_print("could not bind for connect: %d", result);
933 /* This *may* not indicate a critical error */
934 }
935
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100936 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
937
938 log_print("connecting to %d", con->nodeid);
939 result =
940 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
941 O_NONBLOCK);
942 if (result == -EINPROGRESS)
943 result = 0;
944 if (result == 0)
945 goto out;
946
947out_err:
948 if (con->sock) {
949 sock_release(con->sock);
950 con->sock = NULL;
951 }
952 /*
953 * Some errors are fatal and this list might need adjusting. For other
954 * errors we try again until the max number of retries is reached.
955 */
956 if (result != -EHOSTUNREACH && result != -ENETUNREACH &&
Marcin Slusarz0035a4b2008-05-11 22:01:29 +0200957 result != -ENETDOWN && result != -EINVAL
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100958 && result != -EPROTONOSUPPORT) {
959 lowcomms_connect_sock(con);
960 result = 0;
961 }
962out:
963 mutex_unlock(&con->sock_mutex);
964 return;
965}
966
967static struct socket *tcp_create_listen_sock(struct connection *con,
968 struct sockaddr_storage *saddr)
969{
970 struct socket *sock = NULL;
971 int result = 0;
972 int one = 1;
973 int addr_len;
974
975 if (dlm_local_addr[0]->ss_family == AF_INET)
976 addr_len = sizeof(struct sockaddr_in);
977 else
978 addr_len = sizeof(struct sockaddr_in6);
979
980 /* Create a socket to communicate with */
David Teigland617e82e2007-04-26 13:46:49 -0500981 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
982 IPPROTO_TCP, &sock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100983 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -0500984 log_print("Can't create listening comms socket");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100985 goto create_out;
986 }
987
988 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
989 (char *)&one, sizeof(one));
990
991 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -0500992 log_print("Failed to set SO_REUSEADDR on socket: %d", result);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100993 }
994 sock->sk->sk_user_data = con;
995 con->rx_action = tcp_accept_from_sock;
996 con->connect_action = tcp_connect_to_sock;
997 con->sock = sock;
998
999 /* Bind to our port */
1000 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
1001 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
1002 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001003 log_print("Can't bind to port %d", dlm_config.ci_tcp_port);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001004 sock_release(sock);
1005 sock = NULL;
1006 con->sock = NULL;
1007 goto create_out;
1008 }
1009 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
1010 (char *)&one, sizeof(one));
1011 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001012 log_print("Set keepalive failed: %d", result);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001013 }
1014
1015 result = sock->ops->listen(sock, 5);
1016 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001017 log_print("Can't listen on port %d", dlm_config.ci_tcp_port);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001018 sock_release(sock);
1019 sock = NULL;
1020 goto create_out;
1021 }
1022
1023create_out:
1024 return sock;
1025}
1026
1027/* Get local addresses */
1028static void init_local(void)
1029{
1030 struct sockaddr_storage sas, *addr;
1031 int i;
1032
Patrick Caulfield30d3a232007-04-23 16:26:21 +01001033 dlm_local_count = 0;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001034 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
1035 if (dlm_our_addr(&sas, i))
1036 break;
1037
1038 addr = kmalloc(sizeof(*addr), GFP_KERNEL);
1039 if (!addr)
1040 break;
1041 memcpy(addr, &sas, sizeof(*addr));
1042 dlm_local_addr[dlm_local_count++] = addr;
1043 }
1044}
1045
David Teigland617e82e2007-04-26 13:46:49 -05001046/* Bind to an IP address. SCTP allows multiple address so it can do
1047 multi-homing */
1048static int add_sctp_bind_addr(struct connection *sctp_con,
1049 struct sockaddr_storage *addr,
1050 int addr_len, int num)
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001051{
1052 int result = 0;
1053
1054 if (num == 1)
1055 result = kernel_bind(sctp_con->sock,
1056 (struct sockaddr *) addr,
1057 addr_len);
1058 else
1059 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP,
1060 SCTP_SOCKOPT_BINDX_ADD,
1061 (char *)addr, addr_len);
1062
1063 if (result < 0)
1064 log_print("Can't bind to port %d addr number %d",
1065 dlm_config.ci_tcp_port, num);
1066
1067 return result;
1068}
1069
1070/* Initialise SCTP socket and bind to all interfaces */
1071static int sctp_listen_for_all(void)
1072{
1073 struct socket *sock = NULL;
1074 struct sockaddr_storage localaddr;
1075 struct sctp_event_subscribe subscribe;
1076 int result = -EINVAL, num = 1, i, addr_len;
1077 struct connection *con = nodeid2con(0, GFP_KERNEL);
1078 int bufsize = NEEDED_RMEM;
1079
1080 if (!con)
1081 return -ENOMEM;
1082
1083 log_print("Using SCTP for communications");
1084
1085 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
1086 IPPROTO_SCTP, &sock);
1087 if (result < 0) {
1088 log_print("Can't create comms socket, check SCTP is loaded");
1089 goto out;
1090 }
1091
1092 /* Listen for events */
1093 memset(&subscribe, 0, sizeof(subscribe));
1094 subscribe.sctp_data_io_event = 1;
1095 subscribe.sctp_association_event = 1;
1096 subscribe.sctp_send_failure_event = 1;
1097 subscribe.sctp_shutdown_event = 1;
1098 subscribe.sctp_partial_delivery_event = 1;
1099
David S. Millerdf61c952007-11-06 23:48:57 -08001100 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE,
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001101 (char *)&bufsize, sizeof(bufsize));
1102 if (result)
David Teigland617e82e2007-04-26 13:46:49 -05001103 log_print("Error increasing buffer space on socket %d", result);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001104
1105 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
David Teigland617e82e2007-04-26 13:46:49 -05001106 (char *)&subscribe, sizeof(subscribe));
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001107 if (result < 0) {
1108 log_print("Failed to set SCTP_EVENTS on socket: result=%d",
1109 result);
1110 goto create_delsock;
1111 }
1112
1113 /* Init con struct */
1114 sock->sk->sk_user_data = con;
1115 con->sock = sock;
1116 con->sock->sk->sk_data_ready = lowcomms_data_ready;
1117 con->rx_action = receive_from_sock;
1118 con->connect_action = sctp_init_assoc;
1119
1120 /* Bind to all interfaces. */
1121 for (i = 0; i < dlm_local_count; i++) {
1122 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
1123 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len);
1124
1125 result = add_sctp_bind_addr(con, &localaddr, addr_len, num);
1126 if (result)
1127 goto create_delsock;
1128 ++num;
1129 }
1130
1131 result = sock->ops->listen(sock, 5);
1132 if (result < 0) {
1133 log_print("Can't set socket listening");
1134 goto create_delsock;
1135 }
1136
1137 return 0;
1138
1139create_delsock:
1140 sock_release(sock);
1141 con->sock = NULL;
1142out:
1143 return result;
1144}
1145
1146static int tcp_listen_for_all(void)
1147{
1148 struct socket *sock = NULL;
1149 struct connection *con = nodeid2con(0, GFP_KERNEL);
1150 int result = -EINVAL;
1151
1152 if (!con)
1153 return -ENOMEM;
1154
1155 /* We don't support multi-homed hosts */
1156 if (dlm_local_addr[1] != NULL) {
David Teigland617e82e2007-04-26 13:46:49 -05001157 log_print("TCP protocol can't handle multi-homed hosts, "
1158 "try SCTP");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001159 return -EINVAL;
1160 }
1161
1162 log_print("Using TCP for communications");
1163
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001164 sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
1165 if (sock) {
1166 add_sock(sock, con);
1167 result = 0;
1168 }
1169 else {
1170 result = -EADDRINUSE;
1171 }
1172
1173 return result;
1174}
1175
1176
1177
1178static struct writequeue_entry *new_writequeue_entry(struct connection *con,
1179 gfp_t allocation)
1180{
1181 struct writequeue_entry *entry;
1182
1183 entry = kmalloc(sizeof(struct writequeue_entry), allocation);
1184 if (!entry)
1185 return NULL;
1186
1187 entry->page = alloc_page(allocation);
1188 if (!entry->page) {
1189 kfree(entry);
1190 return NULL;
1191 }
1192
1193 entry->offset = 0;
1194 entry->len = 0;
1195 entry->end = 0;
1196 entry->users = 0;
1197 entry->con = con;
1198
1199 return entry;
1200}
1201
David Teigland617e82e2007-04-26 13:46:49 -05001202void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001203{
1204 struct connection *con;
1205 struct writequeue_entry *e;
1206 int offset = 0;
1207 int users = 0;
1208
1209 con = nodeid2con(nodeid, allocation);
1210 if (!con)
1211 return NULL;
1212
1213 spin_lock(&con->writequeue_lock);
1214 e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
1215 if ((&e->list == &con->writequeue) ||
1216 (PAGE_CACHE_SIZE - e->end < len)) {
1217 e = NULL;
1218 } else {
1219 offset = e->end;
1220 e->end += len;
1221 users = e->users++;
1222 }
1223 spin_unlock(&con->writequeue_lock);
1224
1225 if (e) {
1226 got_one:
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001227 *ppc = page_address(e->page) + offset;
1228 return e;
1229 }
1230
1231 e = new_writequeue_entry(con, allocation);
1232 if (e) {
1233 spin_lock(&con->writequeue_lock);
1234 offset = e->end;
1235 e->end += len;
1236 users = e->users++;
1237 list_add_tail(&e->list, &con->writequeue);
1238 spin_unlock(&con->writequeue_lock);
1239 goto got_one;
1240 }
1241 return NULL;
1242}
1243
1244void dlm_lowcomms_commit_buffer(void *mh)
1245{
1246 struct writequeue_entry *e = (struct writequeue_entry *)mh;
1247 struct connection *con = e->con;
1248 int users;
1249
1250 spin_lock(&con->writequeue_lock);
1251 users = --e->users;
1252 if (users)
1253 goto out;
1254 e->len = e->end - e->offset;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001255 spin_unlock(&con->writequeue_lock);
1256
1257 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
1258 queue_work(send_workqueue, &con->swork);
1259 }
1260 return;
1261
1262out:
1263 spin_unlock(&con->writequeue_lock);
1264 return;
1265}
1266
1267/* Send a message */
1268static void send_to_sock(struct connection *con)
1269{
1270 int ret = 0;
1271 ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int);
1272 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1273 struct writequeue_entry *e;
1274 int len, offset;
1275
1276 mutex_lock(&con->sock_mutex);
1277 if (con->sock == NULL)
1278 goto out_connect;
1279
1280 sendpage = con->sock->ops->sendpage;
1281
1282 spin_lock(&con->writequeue_lock);
1283 for (;;) {
1284 e = list_entry(con->writequeue.next, struct writequeue_entry,
1285 list);
1286 if ((struct list_head *) e == &con->writequeue)
1287 break;
1288
1289 len = e->len;
1290 offset = e->offset;
1291 BUG_ON(len == 0 && e->users == 0);
1292 spin_unlock(&con->writequeue_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001293
1294 ret = 0;
1295 if (len) {
1296 ret = sendpage(con->sock, e->page, offset, len,
1297 msg_flags);
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001298 if (ret == -EAGAIN || ret == 0) {
1299 cond_resched();
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001300 goto out;
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001301 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001302 if (ret <= 0)
1303 goto send_error;
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001304 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001305 /* Don't starve people filling buffers */
1306 cond_resched();
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001307
1308 spin_lock(&con->writequeue_lock);
1309 e->offset += ret;
1310 e->len -= ret;
1311
1312 if (e->len == 0 && e->users == 0) {
1313 list_del(&e->list);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001314 free_entry(e);
1315 continue;
1316 }
1317 }
1318 spin_unlock(&con->writequeue_lock);
1319out:
1320 mutex_unlock(&con->sock_mutex);
1321 return;
1322
1323send_error:
1324 mutex_unlock(&con->sock_mutex);
1325 close_connection(con, false);
1326 lowcomms_connect_sock(con);
1327 return;
1328
1329out_connect:
1330 mutex_unlock(&con->sock_mutex);
1331 if (!test_bit(CF_INIT_PENDING, &con->flags))
1332 lowcomms_connect_sock(con);
1333 return;
1334}
1335
1336static void clean_one_writequeue(struct connection *con)
1337{
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001338 struct writequeue_entry *e, *safe;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001339
1340 spin_lock(&con->writequeue_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001341 list_for_each_entry_safe(e, safe, &con->writequeue, list) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001342 list_del(&e->list);
1343 free_entry(e);
1344 }
1345 spin_unlock(&con->writequeue_lock);
1346}
1347
1348/* Called from recovery when it knows that a node has
1349 left the cluster */
1350int dlm_lowcomms_close(int nodeid)
1351{
1352 struct connection *con;
1353
1354 log_print("closing connection to node %d", nodeid);
1355 con = nodeid2con(nodeid, 0);
1356 if (con) {
1357 clean_one_writequeue(con);
1358 close_connection(con, true);
1359 }
1360 return 0;
1361}
1362
1363/* Receive workqueue function */
1364static void process_recv_sockets(struct work_struct *work)
1365{
1366 struct connection *con = container_of(work, struct connection, rwork);
1367 int err;
1368
1369 clear_bit(CF_READ_PENDING, &con->flags);
1370 do {
1371 err = con->rx_action(con);
1372 } while (!err);
1373}
1374
1375/* Send workqueue function */
1376static void process_send_sockets(struct work_struct *work)
1377{
1378 struct connection *con = container_of(work, struct connection, swork);
1379
1380 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
1381 con->connect_action(con);
1382 }
1383 clear_bit(CF_WRITE_PENDING, &con->flags);
1384 send_to_sock(con);
1385}
1386
1387
1388/* Discard all entries on the write queues */
1389static void clean_writequeues(void)
1390{
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001391 foreach_conn(clean_one_writequeue);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001392}
1393
1394static void work_stop(void)
1395{
1396 destroy_workqueue(recv_workqueue);
1397 destroy_workqueue(send_workqueue);
1398}
1399
1400static int work_start(void)
1401{
1402 int error;
1403 recv_workqueue = create_workqueue("dlm_recv");
1404 error = IS_ERR(recv_workqueue);
1405 if (error) {
1406 log_print("can't start dlm_recv %d", error);
1407 return error;
1408 }
1409
1410 send_workqueue = create_singlethread_workqueue("dlm_send");
1411 error = IS_ERR(send_workqueue);
1412 if (error) {
1413 log_print("can't start dlm_send %d", error);
1414 destroy_workqueue(recv_workqueue);
1415 return error;
1416 }
1417
1418 return 0;
1419}
1420
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001421static void stop_conn(struct connection *con)
1422{
1423 con->flags |= 0x0F;
1424 if (con->sock)
1425 con->sock->sk->sk_user_data = NULL;
1426}
1427
1428static void free_conn(struct connection *con)
1429{
1430 close_connection(con, true);
1431 if (con->othercon)
1432 kmem_cache_free(con_cache, con->othercon);
1433 hlist_del(&con->list);
1434 kmem_cache_free(con_cache, con);
1435}
1436
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001437void dlm_lowcomms_stop(void)
1438{
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001439 /* Set all the flags to prevent any
1440 socket activity.
1441 */
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001442 mutex_lock(&connections_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001443 foreach_conn(stop_conn);
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001444 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001445
1446 work_stop();
1447
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001448 mutex_lock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001449 clean_writequeues();
1450
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001451 foreach_conn(free_conn);
1452
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001453 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001454 kmem_cache_destroy(con_cache);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001455}
1456
1457int dlm_lowcomms_start(void)
1458{
1459 int error = -EINVAL;
1460 struct connection *con;
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001461 int i;
1462
1463 for (i = 0; i < CONN_HASH_SIZE; i++)
1464 INIT_HLIST_HEAD(&connection_hash[i]);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001465
1466 init_local();
1467 if (!dlm_local_count) {
David Teigland617e82e2007-04-26 13:46:49 -05001468 error = -ENOTCONN;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001469 log_print("no local IP address has been set");
1470 goto out;
1471 }
1472
1473 error = -ENOMEM;
1474 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
1475 __alignof__(struct connection), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001476 NULL);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001477 if (!con_cache)
1478 goto out;
1479
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001480 /* Start listening */
1481 if (dlm_config.ci_protocol == 0)
1482 error = tcp_listen_for_all();
1483 else
1484 error = sctp_listen_for_all();
1485 if (error)
1486 goto fail_unlisten;
1487
1488 error = work_start();
1489 if (error)
1490 goto fail_unlisten;
1491
1492 return 0;
1493
1494fail_unlisten:
1495 con = nodeid2con(0,0);
1496 if (con) {
1497 close_connection(con, false);
1498 kmem_cache_free(con_cache, con);
1499 }
1500 kmem_cache_destroy(con_cache);
1501
1502out:
1503 return error;
1504}