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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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090054#include <linux/slab.h>
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +010055#include <net/sctp/user.h>
Joe Perches44ad5322009-01-22 13:24:49 -080056#include <net/ipv6.h>
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +010057
58#include "dlm_internal.h"
59#include "lowcomms.h"
60#include "midcomms.h"
61#include "config.h"
62
63#define NEEDED_RMEM (4*1024*1024)
Christine Caulfield5e9ccc32009-01-28 12:57:40 -060064#define CONN_HASH_SIZE 32
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +010065
Bob Petersonf92c8dd2010-11-12 11:15:20 -060066/* Number of messages to send before rescheduling */
67#define MAX_SEND_MSG_COUNT 25
68
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +010069struct cbuf {
70 unsigned int base;
71 unsigned int len;
72 unsigned int mask;
73};
74
75static void cbuf_add(struct cbuf *cb, int n)
76{
77 cb->len += n;
78}
79
80static int cbuf_data(struct cbuf *cb)
81{
82 return ((cb->base + cb->len) & cb->mask);
83}
84
85static void cbuf_init(struct cbuf *cb, int size)
86{
87 cb->base = cb->len = 0;
88 cb->mask = size-1;
89}
90
91static void cbuf_eat(struct cbuf *cb, int n)
92{
93 cb->len -= n;
94 cb->base += n;
95 cb->base &= cb->mask;
96}
97
98static bool cbuf_empty(struct cbuf *cb)
99{
100 return cb->len == 0;
101}
102
103struct connection {
104 struct socket *sock; /* NULL if not connected */
105 uint32_t nodeid; /* So we know who we are in the list */
106 struct mutex sock_mutex;
107 unsigned long flags;
108#define CF_READ_PENDING 1
109#define CF_WRITE_PENDING 2
110#define CF_CONNECT_PENDING 3
111#define CF_INIT_PENDING 4
112#define CF_IS_OTHERCON 5
Lars Marowsky-Bree063c4c92009-08-11 16:18:23 -0500113#define CF_CLOSE 6
David Millerb36930d2010-11-10 21:56:39 -0800114#define CF_APP_LIMITED 7
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100115 struct list_head writequeue; /* List of outgoing writequeue_entries */
116 spinlock_t writequeue_lock;
117 int (*rx_action) (struct connection *); /* What to do when active */
118 void (*connect_action) (struct connection *); /* What to do to connect */
119 struct page *rx_page;
120 struct cbuf cb;
121 int retries;
122#define MAX_CONNECT_RETRIES 3
123 int sctp_assoc;
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600124 struct hlist_node list;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100125 struct connection *othercon;
126 struct work_struct rwork; /* Receive workqueue */
127 struct work_struct swork; /* Send workqueue */
128};
129#define sock2con(x) ((struct connection *)(x)->sk_user_data)
130
131/* An entry waiting to be sent */
132struct writequeue_entry {
133 struct list_head list;
134 struct page *page;
135 int offset;
136 int len;
137 int end;
138 int users;
139 struct connection *con;
140};
141
142static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
143static int dlm_local_count;
144
145/* Work queues */
146static struct workqueue_struct *recv_workqueue;
147static struct workqueue_struct *send_workqueue;
148
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600149static struct hlist_head connection_hash[CONN_HASH_SIZE];
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500150static DEFINE_MUTEX(connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100151static struct kmem_cache *con_cache;
152
153static void process_recv_sockets(struct work_struct *work);
154static void process_send_sockets(struct work_struct *work);
155
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600156
157/* This is deliberately very simple because most clusters have simple
158 sequential nodeids, so we should be able to go straight to a connection
159 struct in the array */
160static inline int nodeid_hash(int nodeid)
161{
162 return nodeid & (CONN_HASH_SIZE-1);
163}
164
165static struct connection *__find_con(int nodeid)
166{
167 int r;
168 struct hlist_node *h;
169 struct connection *con;
170
171 r = nodeid_hash(nodeid);
172
173 hlist_for_each_entry(con, h, &connection_hash[r], list) {
174 if (con->nodeid == nodeid)
175 return con;
176 }
177 return NULL;
178}
179
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100180/*
181 * If 'allocation' is zero then we don't attempt to create a new
182 * connection structure for this node.
183 */
184static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
185{
186 struct connection *con = NULL;
187 int r;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100188
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600189 con = __find_con(nodeid);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100190 if (con || !alloc)
191 return con;
192
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100193 con = kmem_cache_zalloc(con_cache, alloc);
194 if (!con)
195 return NULL;
196
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600197 r = nodeid_hash(nodeid);
198 hlist_add_head(&con->list, &connection_hash[r]);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100199
200 con->nodeid = nodeid;
201 mutex_init(&con->sock_mutex);
202 INIT_LIST_HEAD(&con->writequeue);
203 spin_lock_init(&con->writequeue_lock);
204 INIT_WORK(&con->swork, process_send_sockets);
205 INIT_WORK(&con->rwork, process_recv_sockets);
206
207 /* Setup action pointers for child sockets */
208 if (con->nodeid) {
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600209 struct connection *zerocon = __find_con(0);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100210
211 con->connect_action = zerocon->connect_action;
212 if (!con->rx_action)
213 con->rx_action = zerocon->rx_action;
214 }
215
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100216 return con;
217}
218
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600219/* Loop round all connections */
220static void foreach_conn(void (*conn_func)(struct connection *c))
221{
222 int i;
223 struct hlist_node *h, *n;
224 struct connection *con;
225
226 for (i = 0; i < CONN_HASH_SIZE; i++) {
227 hlist_for_each_entry_safe(con, h, n, &connection_hash[i], list){
228 conn_func(con);
229 }
230 }
231}
232
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100233static struct connection *nodeid2con(int nodeid, gfp_t allocation)
234{
235 struct connection *con;
236
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500237 mutex_lock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100238 con = __nodeid2con(nodeid, allocation);
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500239 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100240
241 return con;
242}
243
244/* This is a bit drastic, but only called when things go wrong */
245static struct connection *assoc2con(int assoc_id)
246{
247 int i;
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600248 struct hlist_node *h;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100249 struct connection *con;
250
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500251 mutex_lock(&connections_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600252
253 for (i = 0 ; i < CONN_HASH_SIZE; i++) {
254 hlist_for_each_entry(con, h, &connection_hash[i], list) {
Julia Lawallf70cb332010-08-03 23:34:16 +0200255 if (con->sctp_assoc == assoc_id) {
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600256 mutex_unlock(&connections_lock);
257 return con;
258 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100259 }
260 }
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500261 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100262 return NULL;
263}
264
265static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
266{
267 struct sockaddr_storage addr;
268 int error;
269
270 if (!dlm_local_count)
271 return -1;
272
273 error = dlm_nodeid_to_addr(nodeid, &addr);
274 if (error)
275 return error;
276
277 if (dlm_local_addr[0]->ss_family == AF_INET) {
278 struct sockaddr_in *in4 = (struct sockaddr_in *) &addr;
279 struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr;
280 ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
281 } else {
282 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr;
283 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr;
Joe Perches44ad5322009-01-22 13:24:49 -0800284 ipv6_addr_copy(&ret6->sin6_addr, &in6->sin6_addr);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100285 }
286
287 return 0;
288}
289
290/* Data available on socket or listen socket received a connect */
291static void lowcomms_data_ready(struct sock *sk, int count_unused)
292{
293 struct connection *con = sock2con(sk);
Patrick Caulfieldafb853f2007-06-01 10:07:26 -0500294 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags))
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100295 queue_work(recv_workqueue, &con->rwork);
296}
297
298static void lowcomms_write_space(struct sock *sk)
299{
300 struct connection *con = sock2con(sk);
301
David Millerb36930d2010-11-10 21:56:39 -0800302 if (!con)
303 return;
304
305 clear_bit(SOCK_NOSPACE, &con->sock->flags);
306
307 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) {
308 con->sock->sk->sk_write_pending--;
309 clear_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags);
310 }
311
312 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100313 queue_work(send_workqueue, &con->swork);
314}
315
316static inline void lowcomms_connect_sock(struct connection *con)
317{
Lars Marowsky-Bree063c4c92009-08-11 16:18:23 -0500318 if (test_bit(CF_CLOSE, &con->flags))
319 return;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100320 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
321 queue_work(send_workqueue, &con->swork);
322}
323
324static void lowcomms_state_change(struct sock *sk)
325{
326 if (sk->sk_state == TCP_ESTABLISHED)
327 lowcomms_write_space(sk);
328}
329
Christine Caulfield391fbdc2009-05-07 10:54:16 -0500330int dlm_lowcomms_connect_node(int nodeid)
331{
332 struct connection *con;
333
David Teigland04bedd72009-09-18 14:31:47 -0500334 /* with sctp there's no connecting without sending */
335 if (dlm_config.ci_protocol != 0)
336 return 0;
337
Christine Caulfield391fbdc2009-05-07 10:54:16 -0500338 if (nodeid == dlm_our_nodeid())
339 return 0;
340
341 con = nodeid2con(nodeid, GFP_NOFS);
342 if (!con)
343 return -ENOMEM;
344 lowcomms_connect_sock(con);
345 return 0;
346}
347
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100348/* Make a socket active */
349static int add_sock(struct socket *sock, struct connection *con)
350{
351 con->sock = sock;
352
353 /* Install a data_ready callback */
354 con->sock->sk->sk_data_ready = lowcomms_data_ready;
355 con->sock->sk->sk_write_space = lowcomms_write_space;
356 con->sock->sk->sk_state_change = lowcomms_state_change;
357 con->sock->sk->sk_user_data = con;
Steven Whitehoused6d7b702008-11-12 16:49:48 -0600358 con->sock->sk->sk_allocation = GFP_NOFS;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100359 return 0;
360}
361
362/* Add the port number to an IPv6 or 4 sockaddr and return the address
363 length */
364static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
365 int *addr_len)
366{
367 saddr->ss_family = dlm_local_addr[0]->ss_family;
368 if (saddr->ss_family == AF_INET) {
369 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
370 in4_addr->sin_port = cpu_to_be16(port);
371 *addr_len = sizeof(struct sockaddr_in);
372 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
373 } else {
374 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
375 in6_addr->sin6_port = cpu_to_be16(port);
376 *addr_len = sizeof(struct sockaddr_in6);
377 }
Patrick Caulfield01c8cab2007-07-17 16:53:15 +0100378 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100379}
380
381/* Close a remote connection and tidy up */
382static void close_connection(struct connection *con, bool and_other)
383{
384 mutex_lock(&con->sock_mutex);
385
386 if (con->sock) {
387 sock_release(con->sock);
388 con->sock = NULL;
389 }
390 if (con->othercon && and_other) {
391 /* Will only re-enter once. */
392 close_connection(con->othercon, false);
393 }
394 if (con->rx_page) {
395 __free_page(con->rx_page);
396 con->rx_page = NULL;
397 }
Patrick Caulfield9e5f2822007-08-02 14:58:14 +0100398
Patrick Caulfield61d96be02007-08-20 15:13:38 +0100399 con->retries = 0;
400 mutex_unlock(&con->sock_mutex);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100401}
402
403/* We only send shutdown messages to nodes that are not part of the cluster */
404static void sctp_send_shutdown(sctp_assoc_t associd)
405{
406 static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
407 struct msghdr outmessage;
408 struct cmsghdr *cmsg;
409 struct sctp_sndrcvinfo *sinfo;
410 int ret;
411 struct connection *con;
412
413 con = nodeid2con(0,0);
414 BUG_ON(con == NULL);
415
416 outmessage.msg_name = NULL;
417 outmessage.msg_namelen = 0;
418 outmessage.msg_control = outcmsg;
419 outmessage.msg_controllen = sizeof(outcmsg);
420 outmessage.msg_flags = MSG_EOR;
421
422 cmsg = CMSG_FIRSTHDR(&outmessage);
423 cmsg->cmsg_level = IPPROTO_SCTP;
424 cmsg->cmsg_type = SCTP_SNDRCV;
425 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
426 outmessage.msg_controllen = cmsg->cmsg_len;
427 sinfo = CMSG_DATA(cmsg);
428 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
429
430 sinfo->sinfo_flags |= MSG_EOF;
431 sinfo->sinfo_assoc_id = associd;
432
433 ret = kernel_sendmsg(con->sock, &outmessage, NULL, 0, 0);
434
435 if (ret != 0)
436 log_print("send EOF to node failed: %d", ret);
437}
438
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600439static void sctp_init_failed_foreach(struct connection *con)
440{
441 con->sctp_assoc = 0;
442 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
443 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
444 queue_work(send_workqueue, &con->swork);
445 }
446}
447
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100448/* INIT failed but we don't know which node...
449 restart INIT on all pending nodes */
450static void sctp_init_failed(void)
451{
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500452 mutex_lock(&connections_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -0600453
454 foreach_conn(sctp_init_failed_foreach);
455
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -0500456 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100457}
458
459/* Something happened to an association */
David Teigland617e82e2007-04-26 13:46:49 -0500460static void process_sctp_notification(struct connection *con,
461 struct msghdr *msg, char *buf)
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100462{
463 union sctp_notification *sn = (union sctp_notification *)buf;
464
465 if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
466 switch (sn->sn_assoc_change.sac_state) {
467
468 case SCTP_COMM_UP:
469 case SCTP_RESTART:
470 {
471 /* Check that the new node is in the lockspace */
472 struct sctp_prim prim;
473 int nodeid;
474 int prim_len, ret;
475 int addr_len;
476 struct connection *new_con;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100477 sctp_peeloff_arg_t parg;
478 int parglen = sizeof(parg);
David Teigland6861f352009-09-24 15:58:23 -0500479 int err;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100480
481 /*
482 * We get this before any data for an association.
483 * We verify that the node is in the cluster and
484 * then peel off a socket for it.
485 */
486 if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
487 log_print("COMM_UP for invalid assoc ID %d",
David Teigland617e82e2007-04-26 13:46:49 -0500488 (int)sn->sn_assoc_change.sac_assoc_id);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100489 sctp_init_failed();
490 return;
491 }
492 memset(&prim, 0, sizeof(struct sctp_prim));
493 prim_len = sizeof(struct sctp_prim);
494 prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
495
496 ret = kernel_getsockopt(con->sock,
497 IPPROTO_SCTP,
498 SCTP_PRIMARY_ADDR,
499 (char*)&prim,
500 &prim_len);
501 if (ret < 0) {
502 log_print("getsockopt/sctp_primary_addr on "
503 "new assoc %d failed : %d",
504 (int)sn->sn_assoc_change.sac_assoc_id,
505 ret);
506
507 /* Retry INIT later */
508 new_con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
509 if (new_con)
510 clear_bit(CF_CONNECT_PENDING, &con->flags);
511 return;
512 }
513 make_sockaddr(&prim.ssp_addr, 0, &addr_len);
514 if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
515 int i;
516 unsigned char *b=(unsigned char *)&prim.ssp_addr;
517 log_print("reject connect from unknown addr");
518 for (i=0; i<sizeof(struct sockaddr_storage);i++)
519 printk("%02x ", b[i]);
520 printk("\n");
521 sctp_send_shutdown(prim.ssp_assoc_id);
522 return;
523 }
524
David Teigland748285c2009-05-15 10:50:57 -0500525 new_con = nodeid2con(nodeid, GFP_NOFS);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100526 if (!new_con)
527 return;
528
529 /* Peel off a new sock */
530 parg.associd = sn->sn_assoc_change.sac_assoc_id;
David Teigland617e82e2007-04-26 13:46:49 -0500531 ret = kernel_getsockopt(con->sock, IPPROTO_SCTP,
532 SCTP_SOCKOPT_PEELOFF,
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100533 (void *)&parg, &parglen);
David Teigland6861f352009-09-24 15:58:23 -0500534 if (ret < 0) {
David Teigland617e82e2007-04-26 13:46:49 -0500535 log_print("Can't peel off a socket for "
David Teigland6861f352009-09-24 15:58:23 -0500536 "connection %d to node %d: err=%d",
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100537 parg.associd, nodeid, ret);
David Teigland6861f352009-09-24 15:58:23 -0500538 return;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100539 }
David Teigland6861f352009-09-24 15:58:23 -0500540 new_con->sock = sockfd_lookup(parg.sd, &err);
541 if (!new_con->sock) {
542 log_print("sockfd_lookup error %d", err);
543 return;
544 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100545 add_sock(new_con->sock, new_con);
David Teigland6861f352009-09-24 15:58:23 -0500546 sockfd_put(new_con->sock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100547
David Teigland6861f352009-09-24 15:58:23 -0500548 log_print("connecting to %d sctp association %d",
549 nodeid, (int)sn->sn_assoc_change.sac_assoc_id);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100550
551 /* Send any pending writes */
552 clear_bit(CF_CONNECT_PENDING, &new_con->flags);
553 clear_bit(CF_INIT_PENDING, &con->flags);
554 if (!test_and_set_bit(CF_WRITE_PENDING, &new_con->flags)) {
555 queue_work(send_workqueue, &new_con->swork);
556 }
557 if (!test_and_set_bit(CF_READ_PENDING, &new_con->flags))
558 queue_work(recv_workqueue, &new_con->rwork);
559 }
560 break;
561
562 case SCTP_COMM_LOST:
563 case SCTP_SHUTDOWN_COMP:
564 {
565 con = assoc2con(sn->sn_assoc_change.sac_assoc_id);
566 if (con) {
567 con->sctp_assoc = 0;
568 }
569 }
570 break;
571
572 /* We don't know which INIT failed, so clear the PENDING flags
573 * on them all. if assoc_id is zero then it will then try
574 * again */
575
576 case SCTP_CANT_STR_ASSOC:
577 {
578 log_print("Can't start SCTP association - retrying");
579 sctp_init_failed();
580 }
581 break;
582
583 default:
584 log_print("unexpected SCTP assoc change id=%d state=%d",
585 (int)sn->sn_assoc_change.sac_assoc_id,
586 sn->sn_assoc_change.sac_state);
587 }
588 }
589}
590
591/* Data received from remote end */
592static int receive_from_sock(struct connection *con)
593{
594 int ret = 0;
595 struct msghdr msg = {};
596 struct kvec iov[2];
597 unsigned len;
598 int r;
599 int call_again_soon = 0;
600 int nvec;
601 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
602
603 mutex_lock(&con->sock_mutex);
604
605 if (con->sock == NULL) {
606 ret = -EAGAIN;
607 goto out_close;
608 }
609
610 if (con->rx_page == NULL) {
611 /*
612 * This doesn't need to be atomic, but I think it should
613 * improve performance if it is.
614 */
615 con->rx_page = alloc_page(GFP_ATOMIC);
616 if (con->rx_page == NULL)
617 goto out_resched;
618 cbuf_init(&con->cb, PAGE_CACHE_SIZE);
619 }
620
621 /* Only SCTP needs these really */
622 memset(&incmsg, 0, sizeof(incmsg));
623 msg.msg_control = incmsg;
624 msg.msg_controllen = sizeof(incmsg);
625
626 /*
627 * iov[0] is the bit of the circular buffer between the current end
628 * point (cb.base + cb.len) and the end of the buffer.
629 */
630 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
631 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
632 iov[1].iov_len = 0;
633 nvec = 1;
634
635 /*
636 * iov[1] is the bit of the circular buffer between the start of the
637 * buffer and the start of the currently used section (cb.base)
638 */
639 if (cbuf_data(&con->cb) >= con->cb.base) {
640 iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);
641 iov[1].iov_len = con->cb.base;
642 iov[1].iov_base = page_address(con->rx_page);
643 nvec = 2;
644 }
645 len = iov[0].iov_len + iov[1].iov_len;
646
647 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
648 MSG_DONTWAIT | MSG_NOSIGNAL);
649 if (ret <= 0)
650 goto out_close;
651
652 /* Process SCTP notifications */
653 if (msg.msg_flags & MSG_NOTIFICATION) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100654 msg.msg_control = incmsg;
655 msg.msg_controllen = sizeof(incmsg);
656
657 process_sctp_notification(con, &msg,
David Teigland617e82e2007-04-26 13:46:49 -0500658 page_address(con->rx_page) + con->cb.base);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100659 mutex_unlock(&con->sock_mutex);
660 return 0;
661 }
662 BUG_ON(con->nodeid == 0);
663
664 if (ret == len)
665 call_again_soon = 1;
666 cbuf_add(&con->cb, ret);
667 ret = dlm_process_incoming_buffer(con->nodeid,
668 page_address(con->rx_page),
669 con->cb.base, con->cb.len,
670 PAGE_CACHE_SIZE);
671 if (ret == -EBADMSG) {
David Teigland617e82e2007-04-26 13:46:49 -0500672 log_print("lowcomms: addr=%p, base=%u, len=%u, "
673 "iov_len=%u, iov_base[0]=%p, read=%d",
674 page_address(con->rx_page), con->cb.base, con->cb.len,
675 len, iov[0].iov_base, r);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100676 }
677 if (ret < 0)
678 goto out_close;
679 cbuf_eat(&con->cb, ret);
680
681 if (cbuf_empty(&con->cb) && !call_again_soon) {
682 __free_page(con->rx_page);
683 con->rx_page = NULL;
684 }
685
686 if (call_again_soon)
687 goto out_resched;
688 mutex_unlock(&con->sock_mutex);
689 return 0;
690
691out_resched:
692 if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
693 queue_work(recv_workqueue, &con->rwork);
694 mutex_unlock(&con->sock_mutex);
695 return -EAGAIN;
696
697out_close:
698 mutex_unlock(&con->sock_mutex);
Patrick Caulfield9e5f2822007-08-02 14:58:14 +0100699 if (ret != -EAGAIN) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100700 close_connection(con, false);
701 /* Reconnect when there is something to send */
702 }
703 /* Don't return success if we really got EOF */
704 if (ret == 0)
705 ret = -EAGAIN;
706
707 return ret;
708}
709
710/* Listening socket is busy, accept a connection */
711static int tcp_accept_from_sock(struct connection *con)
712{
713 int result;
714 struct sockaddr_storage peeraddr;
715 struct socket *newsock;
716 int len;
717 int nodeid;
718 struct connection *newcon;
719 struct connection *addcon;
720
721 memset(&peeraddr, 0, sizeof(peeraddr));
722 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
723 IPPROTO_TCP, &newsock);
724 if (result < 0)
725 return -ENOMEM;
726
727 mutex_lock_nested(&con->sock_mutex, 0);
728
729 result = -ENOTCONN;
730 if (con->sock == NULL)
731 goto accept_err;
732
733 newsock->type = con->sock->type;
734 newsock->ops = con->sock->ops;
735
736 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
737 if (result < 0)
738 goto accept_err;
739
740 /* Get the connected socket's peer */
741 memset(&peeraddr, 0, sizeof(peeraddr));
742 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
743 &len, 2)) {
744 result = -ECONNABORTED;
745 goto accept_err;
746 }
747
748 /* Get the new node's NODEID */
749 make_sockaddr(&peeraddr, 0, &len);
750 if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
David Teigland617e82e2007-04-26 13:46:49 -0500751 log_print("connect from non cluster node");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100752 sock_release(newsock);
753 mutex_unlock(&con->sock_mutex);
754 return -1;
755 }
756
757 log_print("got connection from %d", nodeid);
758
759 /* Check to see if we already have a connection to this node. This
760 * could happen if the two nodes initiate a connection at roughly
761 * the same time and the connections cross on the wire.
762 * In this case we store the incoming one in "othercon"
763 */
David Teigland748285c2009-05-15 10:50:57 -0500764 newcon = nodeid2con(nodeid, GFP_NOFS);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100765 if (!newcon) {
766 result = -ENOMEM;
767 goto accept_err;
768 }
769 mutex_lock_nested(&newcon->sock_mutex, 1);
770 if (newcon->sock) {
771 struct connection *othercon = newcon->othercon;
772
773 if (!othercon) {
David Teigland748285c2009-05-15 10:50:57 -0500774 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100775 if (!othercon) {
David Teigland617e82e2007-04-26 13:46:49 -0500776 log_print("failed to allocate incoming socket");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100777 mutex_unlock(&newcon->sock_mutex);
778 result = -ENOMEM;
779 goto accept_err;
780 }
781 othercon->nodeid = nodeid;
782 othercon->rx_action = receive_from_sock;
783 mutex_init(&othercon->sock_mutex);
784 INIT_WORK(&othercon->swork, process_send_sockets);
785 INIT_WORK(&othercon->rwork, process_recv_sockets);
786 set_bit(CF_IS_OTHERCON, &othercon->flags);
Patrick Caulfield61d96be02007-08-20 15:13:38 +0100787 }
788 if (!othercon->sock) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100789 newcon->othercon = othercon;
Patrick Caulfield97d84832007-06-27 11:36:23 +0100790 othercon->sock = newsock;
791 newsock->sk->sk_user_data = othercon;
792 add_sock(newsock, othercon);
793 addcon = othercon;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100794 }
Patrick Caulfield97d84832007-06-27 11:36:23 +0100795 else {
796 printk("Extra connection from node %d attempted\n", nodeid);
797 result = -EAGAIN;
akpm@linux-foundation.orgf4fadb23c2007-06-27 14:43:37 -0700798 mutex_unlock(&newcon->sock_mutex);
Patrick Caulfield97d84832007-06-27 11:36:23 +0100799 goto accept_err;
800 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100801 }
802 else {
803 newsock->sk->sk_user_data = newcon;
804 newcon->rx_action = receive_from_sock;
805 add_sock(newsock, newcon);
806 addcon = newcon;
807 }
808
809 mutex_unlock(&newcon->sock_mutex);
810
811 /*
812 * Add it to the active queue in case we got data
813 * beween processing the accept adding the socket
814 * to the read_sockets list
815 */
816 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
817 queue_work(recv_workqueue, &addcon->rwork);
818 mutex_unlock(&con->sock_mutex);
819
820 return 0;
821
822accept_err:
823 mutex_unlock(&con->sock_mutex);
824 sock_release(newsock);
825
826 if (result != -EAGAIN)
David Teigland617e82e2007-04-26 13:46:49 -0500827 log_print("error accepting connection from node: %d", result);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100828 return result;
829}
830
831static void free_entry(struct writequeue_entry *e)
832{
833 __free_page(e->page);
834 kfree(e);
835}
836
837/* Initiate an SCTP association.
838 This is a special case of send_to_sock() in that we don't yet have a
839 peeled-off socket for this association, so we use the listening socket
840 and add the primary IP address of the remote node.
841 */
842static void sctp_init_assoc(struct connection *con)
843{
844 struct sockaddr_storage rem_addr;
845 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
846 struct msghdr outmessage;
847 struct cmsghdr *cmsg;
848 struct sctp_sndrcvinfo *sinfo;
849 struct connection *base_con;
850 struct writequeue_entry *e;
851 int len, offset;
852 int ret;
853 int addrlen;
854 struct kvec iov[1];
855
856 if (test_and_set_bit(CF_INIT_PENDING, &con->flags))
857 return;
858
859 if (con->retries++ > MAX_CONNECT_RETRIES)
860 return;
861
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100862 if (nodeid_to_addr(con->nodeid, (struct sockaddr *)&rem_addr)) {
863 log_print("no address for nodeid %d", con->nodeid);
864 return;
865 }
866 base_con = nodeid2con(0, 0);
867 BUG_ON(base_con == NULL);
868
869 make_sockaddr(&rem_addr, dlm_config.ci_tcp_port, &addrlen);
870
871 outmessage.msg_name = &rem_addr;
872 outmessage.msg_namelen = addrlen;
873 outmessage.msg_control = outcmsg;
874 outmessage.msg_controllen = sizeof(outcmsg);
875 outmessage.msg_flags = MSG_EOR;
876
877 spin_lock(&con->writequeue_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100878
David Teigland04bedd72009-09-18 14:31:47 -0500879 if (list_empty(&con->writequeue)) {
880 spin_unlock(&con->writequeue_lock);
881 log_print("writequeue empty for nodeid %d", con->nodeid);
882 return;
883 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100884
David Teigland04bedd72009-09-18 14:31:47 -0500885 e = list_first_entry(&con->writequeue, struct writequeue_entry, list);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100886 len = e->len;
887 offset = e->offset;
888 spin_unlock(&con->writequeue_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100889
890 /* Send the first block off the write queue */
891 iov[0].iov_base = page_address(e->page)+offset;
892 iov[0].iov_len = len;
893
894 cmsg = CMSG_FIRSTHDR(&outmessage);
895 cmsg->cmsg_level = IPPROTO_SCTP;
896 cmsg->cmsg_type = SCTP_SNDRCV;
897 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
898 sinfo = CMSG_DATA(cmsg);
899 memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
900 sinfo->sinfo_ppid = cpu_to_le32(dlm_our_nodeid());
901 outmessage.msg_controllen = cmsg->cmsg_len;
902
903 ret = kernel_sendmsg(base_con->sock, &outmessage, iov, 1, len);
904 if (ret < 0) {
David Teigland617e82e2007-04-26 13:46:49 -0500905 log_print("Send first packet to node %d failed: %d",
906 con->nodeid, ret);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100907
908 /* Try again later */
909 clear_bit(CF_CONNECT_PENDING, &con->flags);
910 clear_bit(CF_INIT_PENDING, &con->flags);
911 }
912 else {
913 spin_lock(&con->writequeue_lock);
914 e->offset += ret;
915 e->len -= ret;
916
917 if (e->len == 0 && e->users == 0) {
918 list_del(&e->list);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100919 free_entry(e);
920 }
921 spin_unlock(&con->writequeue_lock);
922 }
923}
924
925/* Connect a new socket to its peer */
926static void tcp_connect_to_sock(struct connection *con)
927{
928 int result = -EHOSTUNREACH;
Lon Hohberger6bd8fed2007-10-25 18:51:54 -0400929 struct sockaddr_storage saddr, src_addr;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100930 int addr_len;
Casey Dahlina89d63a2009-07-14 12:17:51 -0500931 struct socket *sock = NULL;
David Teiglandcb2d45d2010-11-12 11:12:55 -0600932 int one = 1;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100933
934 if (con->nodeid == 0) {
935 log_print("attempt to connect sock 0 foiled");
936 return;
937 }
938
939 mutex_lock(&con->sock_mutex);
940 if (con->retries++ > MAX_CONNECT_RETRIES)
941 goto out;
942
943 /* Some odd races can cause double-connects, ignore them */
944 if (con->sock) {
945 result = 0;
946 goto out;
947 }
948
949 /* Create a socket to communicate with */
950 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
951 IPPROTO_TCP, &sock);
952 if (result < 0)
953 goto out_err;
954
955 memset(&saddr, 0, sizeof(saddr));
Casey Dahlinb5711b82009-07-28 12:29:05 -0500956 if (dlm_nodeid_to_addr(con->nodeid, &saddr))
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100957 goto out_err;
958
959 sock->sk->sk_user_data = con;
960 con->rx_action = receive_from_sock;
961 con->connect_action = tcp_connect_to_sock;
962 add_sock(sock, con);
963
Lon Hohberger6bd8fed2007-10-25 18:51:54 -0400964 /* Bind to our cluster-known address connecting to avoid
965 routing problems */
966 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr));
967 make_sockaddr(&src_addr, 0, &addr_len);
968 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr,
969 addr_len);
970 if (result < 0) {
971 log_print("could not bind for connect: %d", result);
972 /* This *may* not indicate a critical error */
973 }
974
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100975 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
976
977 log_print("connecting to %d", con->nodeid);
David Teiglandcb2d45d2010-11-12 11:12:55 -0600978
979 /* Turn off Nagle's algorithm */
980 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
981 sizeof(one));
982
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100983 result =
984 sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
985 O_NONBLOCK);
986 if (result == -EINPROGRESS)
987 result = 0;
988 if (result == 0)
989 goto out;
990
991out_err:
992 if (con->sock) {
993 sock_release(con->sock);
994 con->sock = NULL;
Casey Dahlina89d63a2009-07-14 12:17:51 -0500995 } else if (sock) {
996 sock_release(sock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +0100997 }
998 /*
999 * Some errors are fatal and this list might need adjusting. For other
1000 * errors we try again until the max number of retries is reached.
1001 */
1002 if (result != -EHOSTUNREACH && result != -ENETUNREACH &&
Marcin Slusarz0035a4b2008-05-11 22:01:29 +02001003 result != -ENETDOWN && result != -EINVAL
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001004 && result != -EPROTONOSUPPORT) {
1005 lowcomms_connect_sock(con);
1006 result = 0;
1007 }
1008out:
1009 mutex_unlock(&con->sock_mutex);
1010 return;
1011}
1012
1013static struct socket *tcp_create_listen_sock(struct connection *con,
1014 struct sockaddr_storage *saddr)
1015{
1016 struct socket *sock = NULL;
1017 int result = 0;
1018 int one = 1;
1019 int addr_len;
1020
1021 if (dlm_local_addr[0]->ss_family == AF_INET)
1022 addr_len = sizeof(struct sockaddr_in);
1023 else
1024 addr_len = sizeof(struct sockaddr_in6);
1025
1026 /* Create a socket to communicate with */
David Teigland617e82e2007-04-26 13:46:49 -05001027 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_STREAM,
1028 IPPROTO_TCP, &sock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001029 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001030 log_print("Can't create listening comms socket");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001031 goto create_out;
1032 }
1033
David Teiglandcb2d45d2010-11-12 11:12:55 -06001034 /* Turn off Nagle's algorithm */
1035 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
1036 sizeof(one));
1037
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001038 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
1039 (char *)&one, sizeof(one));
1040
1041 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001042 log_print("Failed to set SO_REUSEADDR on socket: %d", result);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001043 }
1044 sock->sk->sk_user_data = con;
1045 con->rx_action = tcp_accept_from_sock;
1046 con->connect_action = tcp_connect_to_sock;
1047 con->sock = sock;
1048
1049 /* Bind to our port */
1050 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
1051 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
1052 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001053 log_print("Can't bind to port %d", dlm_config.ci_tcp_port);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001054 sock_release(sock);
1055 sock = NULL;
1056 con->sock = NULL;
1057 goto create_out;
1058 }
1059 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
1060 (char *)&one, sizeof(one));
1061 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001062 log_print("Set keepalive failed: %d", result);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001063 }
1064
1065 result = sock->ops->listen(sock, 5);
1066 if (result < 0) {
David Teigland617e82e2007-04-26 13:46:49 -05001067 log_print("Can't listen on port %d", dlm_config.ci_tcp_port);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001068 sock_release(sock);
1069 sock = NULL;
1070 goto create_out;
1071 }
1072
1073create_out:
1074 return sock;
1075}
1076
1077/* Get local addresses */
1078static void init_local(void)
1079{
1080 struct sockaddr_storage sas, *addr;
1081 int i;
1082
Patrick Caulfield30d3a232007-04-23 16:26:21 +01001083 dlm_local_count = 0;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001084 for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
1085 if (dlm_our_addr(&sas, i))
1086 break;
1087
David Teigland573c24c2009-11-30 16:34:43 -06001088 addr = kmalloc(sizeof(*addr), GFP_NOFS);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001089 if (!addr)
1090 break;
1091 memcpy(addr, &sas, sizeof(*addr));
1092 dlm_local_addr[dlm_local_count++] = addr;
1093 }
1094}
1095
David Teigland617e82e2007-04-26 13:46:49 -05001096/* Bind to an IP address. SCTP allows multiple address so it can do
1097 multi-homing */
1098static int add_sctp_bind_addr(struct connection *sctp_con,
1099 struct sockaddr_storage *addr,
1100 int addr_len, int num)
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001101{
1102 int result = 0;
1103
1104 if (num == 1)
1105 result = kernel_bind(sctp_con->sock,
1106 (struct sockaddr *) addr,
1107 addr_len);
1108 else
1109 result = kernel_setsockopt(sctp_con->sock, SOL_SCTP,
1110 SCTP_SOCKOPT_BINDX_ADD,
1111 (char *)addr, addr_len);
1112
1113 if (result < 0)
1114 log_print("Can't bind to port %d addr number %d",
1115 dlm_config.ci_tcp_port, num);
1116
1117 return result;
1118}
1119
1120/* Initialise SCTP socket and bind to all interfaces */
1121static int sctp_listen_for_all(void)
1122{
1123 struct socket *sock = NULL;
1124 struct sockaddr_storage localaddr;
1125 struct sctp_event_subscribe subscribe;
1126 int result = -EINVAL, num = 1, i, addr_len;
David Teigland573c24c2009-11-30 16:34:43 -06001127 struct connection *con = nodeid2con(0, GFP_NOFS);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001128 int bufsize = NEEDED_RMEM;
1129
1130 if (!con)
1131 return -ENOMEM;
1132
1133 log_print("Using SCTP for communications");
1134
1135 result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
1136 IPPROTO_SCTP, &sock);
1137 if (result < 0) {
1138 log_print("Can't create comms socket, check SCTP is loaded");
1139 goto out;
1140 }
1141
1142 /* Listen for events */
1143 memset(&subscribe, 0, sizeof(subscribe));
1144 subscribe.sctp_data_io_event = 1;
1145 subscribe.sctp_association_event = 1;
1146 subscribe.sctp_send_failure_event = 1;
1147 subscribe.sctp_shutdown_event = 1;
1148 subscribe.sctp_partial_delivery_event = 1;
1149
David S. Millerdf61c952007-11-06 23:48:57 -08001150 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE,
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001151 (char *)&bufsize, sizeof(bufsize));
1152 if (result)
David Teigland617e82e2007-04-26 13:46:49 -05001153 log_print("Error increasing buffer space on socket %d", result);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001154
1155 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
David Teigland617e82e2007-04-26 13:46:49 -05001156 (char *)&subscribe, sizeof(subscribe));
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001157 if (result < 0) {
1158 log_print("Failed to set SCTP_EVENTS on socket: result=%d",
1159 result);
1160 goto create_delsock;
1161 }
1162
1163 /* Init con struct */
1164 sock->sk->sk_user_data = con;
1165 con->sock = sock;
1166 con->sock->sk->sk_data_ready = lowcomms_data_ready;
1167 con->rx_action = receive_from_sock;
1168 con->connect_action = sctp_init_assoc;
1169
1170 /* Bind to all interfaces. */
1171 for (i = 0; i < dlm_local_count; i++) {
1172 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
1173 make_sockaddr(&localaddr, dlm_config.ci_tcp_port, &addr_len);
1174
1175 result = add_sctp_bind_addr(con, &localaddr, addr_len, num);
1176 if (result)
1177 goto create_delsock;
1178 ++num;
1179 }
1180
1181 result = sock->ops->listen(sock, 5);
1182 if (result < 0) {
1183 log_print("Can't set socket listening");
1184 goto create_delsock;
1185 }
1186
1187 return 0;
1188
1189create_delsock:
1190 sock_release(sock);
1191 con->sock = NULL;
1192out:
1193 return result;
1194}
1195
1196static int tcp_listen_for_all(void)
1197{
1198 struct socket *sock = NULL;
David Teigland573c24c2009-11-30 16:34:43 -06001199 struct connection *con = nodeid2con(0, GFP_NOFS);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001200 int result = -EINVAL;
1201
1202 if (!con)
1203 return -ENOMEM;
1204
1205 /* We don't support multi-homed hosts */
1206 if (dlm_local_addr[1] != NULL) {
David Teigland617e82e2007-04-26 13:46:49 -05001207 log_print("TCP protocol can't handle multi-homed hosts, "
1208 "try SCTP");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001209 return -EINVAL;
1210 }
1211
1212 log_print("Using TCP for communications");
1213
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001214 sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
1215 if (sock) {
1216 add_sock(sock, con);
1217 result = 0;
1218 }
1219 else {
1220 result = -EADDRINUSE;
1221 }
1222
1223 return result;
1224}
1225
1226
1227
1228static struct writequeue_entry *new_writequeue_entry(struct connection *con,
1229 gfp_t allocation)
1230{
1231 struct writequeue_entry *entry;
1232
1233 entry = kmalloc(sizeof(struct writequeue_entry), allocation);
1234 if (!entry)
1235 return NULL;
1236
1237 entry->page = alloc_page(allocation);
1238 if (!entry->page) {
1239 kfree(entry);
1240 return NULL;
1241 }
1242
1243 entry->offset = 0;
1244 entry->len = 0;
1245 entry->end = 0;
1246 entry->users = 0;
1247 entry->con = con;
1248
1249 return entry;
1250}
1251
David Teigland617e82e2007-04-26 13:46:49 -05001252void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001253{
1254 struct connection *con;
1255 struct writequeue_entry *e;
1256 int offset = 0;
1257 int users = 0;
1258
1259 con = nodeid2con(nodeid, allocation);
1260 if (!con)
1261 return NULL;
1262
1263 spin_lock(&con->writequeue_lock);
1264 e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
1265 if ((&e->list == &con->writequeue) ||
1266 (PAGE_CACHE_SIZE - e->end < len)) {
1267 e = NULL;
1268 } else {
1269 offset = e->end;
1270 e->end += len;
1271 users = e->users++;
1272 }
1273 spin_unlock(&con->writequeue_lock);
1274
1275 if (e) {
1276 got_one:
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001277 *ppc = page_address(e->page) + offset;
1278 return e;
1279 }
1280
1281 e = new_writequeue_entry(con, allocation);
1282 if (e) {
1283 spin_lock(&con->writequeue_lock);
1284 offset = e->end;
1285 e->end += len;
1286 users = e->users++;
1287 list_add_tail(&e->list, &con->writequeue);
1288 spin_unlock(&con->writequeue_lock);
1289 goto got_one;
1290 }
1291 return NULL;
1292}
1293
1294void dlm_lowcomms_commit_buffer(void *mh)
1295{
1296 struct writequeue_entry *e = (struct writequeue_entry *)mh;
1297 struct connection *con = e->con;
1298 int users;
1299
1300 spin_lock(&con->writequeue_lock);
1301 users = --e->users;
1302 if (users)
1303 goto out;
1304 e->len = e->end - e->offset;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001305 spin_unlock(&con->writequeue_lock);
1306
1307 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
1308 queue_work(send_workqueue, &con->swork);
1309 }
1310 return;
1311
1312out:
1313 spin_unlock(&con->writequeue_lock);
1314 return;
1315}
1316
1317/* Send a message */
1318static void send_to_sock(struct connection *con)
1319{
1320 int ret = 0;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001321 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1322 struct writequeue_entry *e;
1323 int len, offset;
Bob Petersonf92c8dd2010-11-12 11:15:20 -06001324 int count = 0;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001325
1326 mutex_lock(&con->sock_mutex);
1327 if (con->sock == NULL)
1328 goto out_connect;
1329
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001330 spin_lock(&con->writequeue_lock);
1331 for (;;) {
1332 e = list_entry(con->writequeue.next, struct writequeue_entry,
1333 list);
1334 if ((struct list_head *) e == &con->writequeue)
1335 break;
1336
1337 len = e->len;
1338 offset = e->offset;
1339 BUG_ON(len == 0 && e->users == 0);
1340 spin_unlock(&con->writequeue_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001341
1342 ret = 0;
1343 if (len) {
Paolo Bonzini1329e3f2009-08-24 13:18:04 -05001344 ret = kernel_sendpage(con->sock, e->page, offset, len,
1345 msg_flags);
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001346 if (ret == -EAGAIN || ret == 0) {
David Millerb36930d2010-11-10 21:56:39 -08001347 if (ret == -EAGAIN &&
1348 test_bit(SOCK_ASYNC_NOSPACE, &con->sock->flags) &&
1349 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) {
1350 /* Notify TCP that we're limited by the
1351 * application window size.
1352 */
1353 set_bit(SOCK_NOSPACE, &con->sock->flags);
1354 con->sock->sk->sk_write_pending++;
1355 }
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001356 cond_resched();
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001357 goto out;
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001358 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001359 if (ret <= 0)
1360 goto send_error;
Patrick Caulfieldd66f8272007-09-14 08:49:21 +01001361 }
Bob Petersonf92c8dd2010-11-12 11:15:20 -06001362
1363 /* Don't starve people filling buffers */
1364 if (++count >= MAX_SEND_MSG_COUNT) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001365 cond_resched();
Bob Petersonf92c8dd2010-11-12 11:15:20 -06001366 count = 0;
1367 }
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001368
1369 spin_lock(&con->writequeue_lock);
1370 e->offset += ret;
1371 e->len -= ret;
1372
1373 if (e->len == 0 && e->users == 0) {
1374 list_del(&e->list);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001375 free_entry(e);
1376 continue;
1377 }
1378 }
1379 spin_unlock(&con->writequeue_lock);
1380out:
1381 mutex_unlock(&con->sock_mutex);
1382 return;
1383
1384send_error:
1385 mutex_unlock(&con->sock_mutex);
1386 close_connection(con, false);
1387 lowcomms_connect_sock(con);
1388 return;
1389
1390out_connect:
1391 mutex_unlock(&con->sock_mutex);
1392 if (!test_bit(CF_INIT_PENDING, &con->flags))
1393 lowcomms_connect_sock(con);
1394 return;
1395}
1396
1397static void clean_one_writequeue(struct connection *con)
1398{
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001399 struct writequeue_entry *e, *safe;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001400
1401 spin_lock(&con->writequeue_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001402 list_for_each_entry_safe(e, safe, &con->writequeue, list) {
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001403 list_del(&e->list);
1404 free_entry(e);
1405 }
1406 spin_unlock(&con->writequeue_lock);
1407}
1408
1409/* Called from recovery when it knows that a node has
1410 left the cluster */
1411int dlm_lowcomms_close(int nodeid)
1412{
1413 struct connection *con;
1414
1415 log_print("closing connection to node %d", nodeid);
1416 con = nodeid2con(nodeid, 0);
1417 if (con) {
Lars Marowsky-Bree063c4c92009-08-11 16:18:23 -05001418 clear_bit(CF_CONNECT_PENDING, &con->flags);
1419 clear_bit(CF_WRITE_PENDING, &con->flags);
1420 set_bit(CF_CLOSE, &con->flags);
1421 if (cancel_work_sync(&con->swork))
1422 log_print("canceled swork for node %d", nodeid);
1423 if (cancel_work_sync(&con->rwork))
1424 log_print("canceled rwork for node %d", nodeid);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001425 clean_one_writequeue(con);
1426 close_connection(con, true);
1427 }
1428 return 0;
1429}
1430
1431/* Receive workqueue function */
1432static void process_recv_sockets(struct work_struct *work)
1433{
1434 struct connection *con = container_of(work, struct connection, rwork);
1435 int err;
1436
1437 clear_bit(CF_READ_PENDING, &con->flags);
1438 do {
1439 err = con->rx_action(con);
1440 } while (!err);
1441}
1442
1443/* Send workqueue function */
1444static void process_send_sockets(struct work_struct *work)
1445{
1446 struct connection *con = container_of(work, struct connection, swork);
1447
1448 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
1449 con->connect_action(con);
Lars Marowsky-Bree063c4c92009-08-11 16:18:23 -05001450 set_bit(CF_WRITE_PENDING, &con->flags);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001451 }
Lars Marowsky-Bree063c4c92009-08-11 16:18:23 -05001452 if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags))
1453 send_to_sock(con);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001454}
1455
1456
1457/* Discard all entries on the write queues */
1458static void clean_writequeues(void)
1459{
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001460 foreach_conn(clean_one_writequeue);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001461}
1462
1463static void work_stop(void)
1464{
1465 destroy_workqueue(recv_workqueue);
1466 destroy_workqueue(send_workqueue);
1467}
1468
1469static int work_start(void)
1470{
Steven Whitehousedcce2402010-11-12 12:12:29 +00001471 recv_workqueue = alloc_workqueue("dlm_recv", WQ_MEM_RECLAIM |
1472 WQ_HIGHPRI | WQ_FREEZEABLE, 0);
Namhyung Kimb9d41052010-12-13 13:42:24 -06001473 if (!recv_workqueue) {
1474 log_print("can't start dlm_recv");
1475 return -ENOMEM;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001476 }
1477
Steven Whitehousedcce2402010-11-12 12:12:29 +00001478 send_workqueue = alloc_workqueue("dlm_send", WQ_MEM_RECLAIM |
1479 WQ_HIGHPRI | WQ_FREEZEABLE, 0);
Namhyung Kimb9d41052010-12-13 13:42:24 -06001480 if (!send_workqueue) {
1481 log_print("can't start dlm_send");
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001482 destroy_workqueue(recv_workqueue);
Namhyung Kimb9d41052010-12-13 13:42:24 -06001483 return -ENOMEM;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001484 }
1485
1486 return 0;
1487}
1488
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001489static void stop_conn(struct connection *con)
1490{
1491 con->flags |= 0x0F;
Christine Caulfield391fbdc2009-05-07 10:54:16 -05001492 if (con->sock && con->sock->sk)
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001493 con->sock->sk->sk_user_data = NULL;
1494}
1495
1496static void free_conn(struct connection *con)
1497{
1498 close_connection(con, true);
1499 if (con->othercon)
1500 kmem_cache_free(con_cache, con->othercon);
1501 hlist_del(&con->list);
1502 kmem_cache_free(con_cache, con);
1503}
1504
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001505void dlm_lowcomms_stop(void)
1506{
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001507 /* Set all the flags to prevent any
1508 socket activity.
1509 */
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001510 mutex_lock(&connections_lock);
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001511 foreach_conn(stop_conn);
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001512 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001513
1514 work_stop();
1515
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001516 mutex_lock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001517 clean_writequeues();
1518
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001519 foreach_conn(free_conn);
1520
Matthias Kaehlcke7a936ce2008-05-12 10:04:51 -05001521 mutex_unlock(&connections_lock);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001522 kmem_cache_destroy(con_cache);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001523}
1524
1525int dlm_lowcomms_start(void)
1526{
1527 int error = -EINVAL;
1528 struct connection *con;
Christine Caulfield5e9ccc32009-01-28 12:57:40 -06001529 int i;
1530
1531 for (i = 0; i < CONN_HASH_SIZE; i++)
1532 INIT_HLIST_HEAD(&connection_hash[i]);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001533
1534 init_local();
1535 if (!dlm_local_count) {
David Teigland617e82e2007-04-26 13:46:49 -05001536 error = -ENOTCONN;
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001537 log_print("no local IP address has been set");
1538 goto out;
1539 }
1540
1541 error = -ENOMEM;
1542 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
1543 __alignof__(struct connection), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001544 NULL);
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001545 if (!con_cache)
1546 goto out;
1547
Patrick Caulfield6ed7257b2007-04-17 15:39:57 +01001548 /* Start listening */
1549 if (dlm_config.ci_protocol == 0)
1550 error = tcp_listen_for_all();
1551 else
1552 error = sctp_listen_for_all();
1553 if (error)
1554 goto fail_unlisten;
1555
1556 error = work_start();
1557 if (error)
1558 goto fail_unlisten;
1559
1560 return 0;
1561
1562fail_unlisten:
1563 con = nodeid2con(0,0);
1564 if (con) {
1565 close_connection(con, false);
1566 kmem_cache_free(con_cache, con);
1567 }
1568 kmem_cache_destroy(con_cache);
1569
1570out:
1571 return error;
1572}