1 /******************************************************************************
2 *******************************************************************************
4 ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
5 ** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
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.
11 *******************************************************************************
12 ******************************************************************************/
17 * This is the "low-level" comms layer.
19 * It is responsible for sending/receiving messages
20 * from other nodes in the cluster.
22 * Cluster nodes are referred to by their nodeids. nodeids are
23 * simply 32 bit numbers to the locking module - if they need to
24 * be expanded for the cluster infrastructure then that is its
25 * responsibility. It is this layer's
26 * responsibility to resolve these into IP address or
27 * whatever it needs for inter-node communication.
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.
39 * lowcomms will choose to use either TCP or SCTP as its transport layer
40 * depending on the configuration variable 'protocol'. This should be set
41 * to 0 (default) for TCP or 1 for SCTP. It should be configured using a
42 * cluster-wide mechanism as it must be the same on all nodes of the cluster
43 * for the DLM to function.
47 #include <asm/ioctls.h>
50 #include <linux/pagemap.h>
51 #include <linux/file.h>
52 #include <linux/mutex.h>
53 #include <linux/sctp.h>
54 #include <net/sctp/user.h>
57 #include "dlm_internal.h"
62 #define NEEDED_RMEM (4*1024*1024)
63 #define CONN_HASH_SIZE 32
71 static void cbuf_add(struct cbuf
*cb
, int n
)
76 static int cbuf_data(struct cbuf
*cb
)
78 return ((cb
->base
+ cb
->len
) & cb
->mask
);
81 static void cbuf_init(struct cbuf
*cb
, int size
)
83 cb
->base
= cb
->len
= 0;
87 static void cbuf_eat(struct cbuf
*cb
, int n
)
94 static bool cbuf_empty(struct cbuf
*cb
)
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
;
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
110 struct list_head writequeue
; /* List of outgoing writequeue_entries */
111 spinlock_t writequeue_lock
;
112 int (*rx_action
) (struct connection
*); /* What to do when active */
113 void (*connect_action
) (struct connection
*); /* What to do to connect */
114 struct page
*rx_page
;
117 #define MAX_CONNECT_RETRIES 3
119 struct hlist_node list
;
120 struct connection
*othercon
;
121 struct work_struct rwork
; /* Receive workqueue */
122 struct work_struct swork
; /* Send workqueue */
124 #define sock2con(x) ((struct connection *)(x)->sk_user_data)
126 /* An entry waiting to be sent */
127 struct writequeue_entry
{
128 struct list_head list
;
134 struct connection
*con
;
137 static struct sockaddr_storage
*dlm_local_addr
[DLM_MAX_ADDR_COUNT
];
138 static int dlm_local_count
;
141 static struct workqueue_struct
*recv_workqueue
;
142 static struct workqueue_struct
*send_workqueue
;
144 static struct hlist_head connection_hash
[CONN_HASH_SIZE
];
145 static DEFINE_MUTEX(connections_lock
);
146 static struct kmem_cache
*con_cache
;
148 static void process_recv_sockets(struct work_struct
*work
);
149 static void process_send_sockets(struct work_struct
*work
);
152 /* This is deliberately very simple because most clusters have simple
153 sequential nodeids, so we should be able to go straight to a connection
154 struct in the array */
155 static inline int nodeid_hash(int nodeid
)
157 return nodeid
& (CONN_HASH_SIZE
-1);
160 static struct connection
*__find_con(int nodeid
)
163 struct hlist_node
*h
;
164 struct connection
*con
;
166 r
= nodeid_hash(nodeid
);
168 hlist_for_each_entry(con
, h
, &connection_hash
[r
], list
) {
169 if (con
->nodeid
== nodeid
)
176 * If 'allocation' is zero then we don't attempt to create a new
177 * connection structure for this node.
179 static struct connection
*__nodeid2con(int nodeid
, gfp_t alloc
)
181 struct connection
*con
= NULL
;
184 con
= __find_con(nodeid
);
188 con
= kmem_cache_zalloc(con_cache
, alloc
);
192 r
= nodeid_hash(nodeid
);
193 hlist_add_head(&con
->list
, &connection_hash
[r
]);
195 con
->nodeid
= nodeid
;
196 mutex_init(&con
->sock_mutex
);
197 INIT_LIST_HEAD(&con
->writequeue
);
198 spin_lock_init(&con
->writequeue_lock
);
199 INIT_WORK(&con
->swork
, process_send_sockets
);
200 INIT_WORK(&con
->rwork
, process_recv_sockets
);
202 /* Setup action pointers for child sockets */
204 struct connection
*zerocon
= __find_con(0);
206 con
->connect_action
= zerocon
->connect_action
;
208 con
->rx_action
= zerocon
->rx_action
;
214 /* Loop round all connections */
215 static void foreach_conn(void (*conn_func
)(struct connection
*c
))
218 struct hlist_node
*h
, *n
;
219 struct connection
*con
;
221 for (i
= 0; i
< CONN_HASH_SIZE
; i
++) {
222 hlist_for_each_entry_safe(con
, h
, n
, &connection_hash
[i
], list
){
228 static struct connection
*nodeid2con(int nodeid
, gfp_t allocation
)
230 struct connection
*con
;
232 mutex_lock(&connections_lock
);
233 con
= __nodeid2con(nodeid
, allocation
);
234 mutex_unlock(&connections_lock
);
239 /* This is a bit drastic, but only called when things go wrong */
240 static struct connection
*assoc2con(int assoc_id
)
243 struct hlist_node
*h
;
244 struct connection
*con
;
246 mutex_lock(&connections_lock
);
248 for (i
= 0 ; i
< CONN_HASH_SIZE
; i
++) {
249 hlist_for_each_entry(con
, h
, &connection_hash
[i
], list
) {
250 if (con
&& con
->sctp_assoc
== assoc_id
) {
251 mutex_unlock(&connections_lock
);
256 mutex_unlock(&connections_lock
);
260 static int nodeid_to_addr(int nodeid
, struct sockaddr
*retaddr
)
262 struct sockaddr_storage addr
;
265 if (!dlm_local_count
)
268 error
= dlm_nodeid_to_addr(nodeid
, &addr
);
272 if (dlm_local_addr
[0]->ss_family
== AF_INET
) {
273 struct sockaddr_in
*in4
= (struct sockaddr_in
*) &addr
;
274 struct sockaddr_in
*ret4
= (struct sockaddr_in
*) retaddr
;
275 ret4
->sin_addr
.s_addr
= in4
->sin_addr
.s_addr
;
277 struct sockaddr_in6
*in6
= (struct sockaddr_in6
*) &addr
;
278 struct sockaddr_in6
*ret6
= (struct sockaddr_in6
*) retaddr
;
279 ipv6_addr_copy(&ret6
->sin6_addr
, &in6
->sin6_addr
);
285 /* Data available on socket or listen socket received a connect */
286 static void lowcomms_data_ready(struct sock
*sk
, int count_unused
)
288 struct connection
*con
= sock2con(sk
);
289 if (con
&& !test_and_set_bit(CF_READ_PENDING
, &con
->flags
))
290 queue_work(recv_workqueue
, &con
->rwork
);
293 static void lowcomms_write_space(struct sock
*sk
)
295 struct connection
*con
= sock2con(sk
);
297 if (con
&& !test_and_set_bit(CF_WRITE_PENDING
, &con
->flags
))
298 queue_work(send_workqueue
, &con
->swork
);
301 static inline void lowcomms_connect_sock(struct connection
*con
)
303 if (test_bit(CF_CLOSE
, &con
->flags
))
305 if (!test_and_set_bit(CF_CONNECT_PENDING
, &con
->flags
))
306 queue_work(send_workqueue
, &con
->swork
);
309 static void lowcomms_state_change(struct sock
*sk
)
311 if (sk
->sk_state
== TCP_ESTABLISHED
)
312 lowcomms_write_space(sk
);
315 int dlm_lowcomms_connect_node(int nodeid
)
317 struct connection
*con
;
319 if (nodeid
== dlm_our_nodeid())
322 con
= nodeid2con(nodeid
, GFP_NOFS
);
325 lowcomms_connect_sock(con
);
329 /* Make a socket active */
330 static int add_sock(struct socket
*sock
, struct connection
*con
)
334 /* Install a data_ready callback */
335 con
->sock
->sk
->sk_data_ready
= lowcomms_data_ready
;
336 con
->sock
->sk
->sk_write_space
= lowcomms_write_space
;
337 con
->sock
->sk
->sk_state_change
= lowcomms_state_change
;
338 con
->sock
->sk
->sk_user_data
= con
;
339 con
->sock
->sk
->sk_allocation
= GFP_NOFS
;
343 /* Add the port number to an IPv6 or 4 sockaddr and return the address
345 static void make_sockaddr(struct sockaddr_storage
*saddr
, uint16_t port
,
348 saddr
->ss_family
= dlm_local_addr
[0]->ss_family
;
349 if (saddr
->ss_family
== AF_INET
) {
350 struct sockaddr_in
*in4_addr
= (struct sockaddr_in
*)saddr
;
351 in4_addr
->sin_port
= cpu_to_be16(port
);
352 *addr_len
= sizeof(struct sockaddr_in
);
353 memset(&in4_addr
->sin_zero
, 0, sizeof(in4_addr
->sin_zero
));
355 struct sockaddr_in6
*in6_addr
= (struct sockaddr_in6
*)saddr
;
356 in6_addr
->sin6_port
= cpu_to_be16(port
);
357 *addr_len
= sizeof(struct sockaddr_in6
);
359 memset((char *)saddr
+ *addr_len
, 0, sizeof(struct sockaddr_storage
) - *addr_len
);
362 /* Close a remote connection and tidy up */
363 static void close_connection(struct connection
*con
, bool and_other
)
365 mutex_lock(&con
->sock_mutex
);
368 sock_release(con
->sock
);
371 if (con
->othercon
&& and_other
) {
372 /* Will only re-enter once. */
373 close_connection(con
->othercon
, false);
376 __free_page(con
->rx_page
);
381 mutex_unlock(&con
->sock_mutex
);
384 /* We only send shutdown messages to nodes that are not part of the cluster */
385 static void sctp_send_shutdown(sctp_assoc_t associd
)
387 static char outcmsg
[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo
))];
388 struct msghdr outmessage
;
389 struct cmsghdr
*cmsg
;
390 struct sctp_sndrcvinfo
*sinfo
;
392 struct connection
*con
;
394 con
= nodeid2con(0,0);
397 outmessage
.msg_name
= NULL
;
398 outmessage
.msg_namelen
= 0;
399 outmessage
.msg_control
= outcmsg
;
400 outmessage
.msg_controllen
= sizeof(outcmsg
);
401 outmessage
.msg_flags
= MSG_EOR
;
403 cmsg
= CMSG_FIRSTHDR(&outmessage
);
404 cmsg
->cmsg_level
= IPPROTO_SCTP
;
405 cmsg
->cmsg_type
= SCTP_SNDRCV
;
406 cmsg
->cmsg_len
= CMSG_LEN(sizeof(struct sctp_sndrcvinfo
));
407 outmessage
.msg_controllen
= cmsg
->cmsg_len
;
408 sinfo
= CMSG_DATA(cmsg
);
409 memset(sinfo
, 0x00, sizeof(struct sctp_sndrcvinfo
));
411 sinfo
->sinfo_flags
|= MSG_EOF
;
412 sinfo
->sinfo_assoc_id
= associd
;
414 ret
= kernel_sendmsg(con
->sock
, &outmessage
, NULL
, 0, 0);
417 log_print("send EOF to node failed: %d", ret
);
420 static void sctp_init_failed_foreach(struct connection
*con
)
423 if (test_and_clear_bit(CF_CONNECT_PENDING
, &con
->flags
)) {
424 if (!test_and_set_bit(CF_WRITE_PENDING
, &con
->flags
))
425 queue_work(send_workqueue
, &con
->swork
);
429 /* INIT failed but we don't know which node...
430 restart INIT on all pending nodes */
431 static void sctp_init_failed(void)
433 mutex_lock(&connections_lock
);
435 foreach_conn(sctp_init_failed_foreach
);
437 mutex_unlock(&connections_lock
);
440 /* Something happened to an association */
441 static void process_sctp_notification(struct connection
*con
,
442 struct msghdr
*msg
, char *buf
)
444 union sctp_notification
*sn
= (union sctp_notification
*)buf
;
446 if (sn
->sn_header
.sn_type
== SCTP_ASSOC_CHANGE
) {
447 switch (sn
->sn_assoc_change
.sac_state
) {
452 /* Check that the new node is in the lockspace */
453 struct sctp_prim prim
;
457 struct connection
*new_con
;
459 sctp_peeloff_arg_t parg
;
460 int parglen
= sizeof(parg
);
463 * We get this before any data for an association.
464 * We verify that the node is in the cluster and
465 * then peel off a socket for it.
467 if ((int)sn
->sn_assoc_change
.sac_assoc_id
<= 0) {
468 log_print("COMM_UP for invalid assoc ID %d",
469 (int)sn
->sn_assoc_change
.sac_assoc_id
);
473 memset(&prim
, 0, sizeof(struct sctp_prim
));
474 prim_len
= sizeof(struct sctp_prim
);
475 prim
.ssp_assoc_id
= sn
->sn_assoc_change
.sac_assoc_id
;
477 ret
= kernel_getsockopt(con
->sock
,
483 log_print("getsockopt/sctp_primary_addr on "
484 "new assoc %d failed : %d",
485 (int)sn
->sn_assoc_change
.sac_assoc_id
,
488 /* Retry INIT later */
489 new_con
= assoc2con(sn
->sn_assoc_change
.sac_assoc_id
);
491 clear_bit(CF_CONNECT_PENDING
, &con
->flags
);
494 make_sockaddr(&prim
.ssp_addr
, 0, &addr_len
);
495 if (dlm_addr_to_nodeid(&prim
.ssp_addr
, &nodeid
)) {
497 unsigned char *b
=(unsigned char *)&prim
.ssp_addr
;
498 log_print("reject connect from unknown addr");
499 for (i
=0; i
<sizeof(struct sockaddr_storage
);i
++)
500 printk("%02x ", b
[i
]);
502 sctp_send_shutdown(prim
.ssp_assoc_id
);
506 new_con
= nodeid2con(nodeid
, GFP_NOFS
);
510 /* Peel off a new sock */
511 parg
.associd
= sn
->sn_assoc_change
.sac_assoc_id
;
512 ret
= kernel_getsockopt(con
->sock
, IPPROTO_SCTP
,
513 SCTP_SOCKOPT_PEELOFF
,
514 (void *)&parg
, &parglen
);
516 log_print("Can't peel off a socket for "
517 "connection %d to node %d: err=%d\n",
518 parg
.associd
, nodeid
, ret
);
520 file
= fget(parg
.sd
);
521 new_con
->sock
= SOCKET_I(file
->f_dentry
->d_inode
);
522 add_sock(new_con
->sock
, new_con
);
524 put_unused_fd(parg
.sd
);
526 log_print("got new/restarted association %d nodeid %d",
527 (int)sn
->sn_assoc_change
.sac_assoc_id
, nodeid
);
529 /* Send any pending writes */
530 clear_bit(CF_CONNECT_PENDING
, &new_con
->flags
);
531 clear_bit(CF_INIT_PENDING
, &con
->flags
);
532 if (!test_and_set_bit(CF_WRITE_PENDING
, &new_con
->flags
)) {
533 queue_work(send_workqueue
, &new_con
->swork
);
535 if (!test_and_set_bit(CF_READ_PENDING
, &new_con
->flags
))
536 queue_work(recv_workqueue
, &new_con
->rwork
);
541 case SCTP_SHUTDOWN_COMP
:
543 con
= assoc2con(sn
->sn_assoc_change
.sac_assoc_id
);
550 /* We don't know which INIT failed, so clear the PENDING flags
551 * on them all. if assoc_id is zero then it will then try
554 case SCTP_CANT_STR_ASSOC
:
556 log_print("Can't start SCTP association - retrying");
562 log_print("unexpected SCTP assoc change id=%d state=%d",
563 (int)sn
->sn_assoc_change
.sac_assoc_id
,
564 sn
->sn_assoc_change
.sac_state
);
569 /* Data received from remote end */
570 static int receive_from_sock(struct connection
*con
)
573 struct msghdr msg
= {};
577 int call_again_soon
= 0;
579 char incmsg
[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo
))];
581 mutex_lock(&con
->sock_mutex
);
583 if (con
->sock
== NULL
) {
588 if (con
->rx_page
== NULL
) {
590 * This doesn't need to be atomic, but I think it should
591 * improve performance if it is.
593 con
->rx_page
= alloc_page(GFP_ATOMIC
);
594 if (con
->rx_page
== NULL
)
596 cbuf_init(&con
->cb
, PAGE_CACHE_SIZE
);
599 /* Only SCTP needs these really */
600 memset(&incmsg
, 0, sizeof(incmsg
));
601 msg
.msg_control
= incmsg
;
602 msg
.msg_controllen
= sizeof(incmsg
);
605 * iov[0] is the bit of the circular buffer between the current end
606 * point (cb.base + cb.len) and the end of the buffer.
608 iov
[0].iov_len
= con
->cb
.base
- cbuf_data(&con
->cb
);
609 iov
[0].iov_base
= page_address(con
->rx_page
) + cbuf_data(&con
->cb
);
614 * iov[1] is the bit of the circular buffer between the start of the
615 * buffer and the start of the currently used section (cb.base)
617 if (cbuf_data(&con
->cb
) >= con
->cb
.base
) {
618 iov
[0].iov_len
= PAGE_CACHE_SIZE
- cbuf_data(&con
->cb
);
619 iov
[1].iov_len
= con
->cb
.base
;
620 iov
[1].iov_base
= page_address(con
->rx_page
);
623 len
= iov
[0].iov_len
+ iov
[1].iov_len
;
625 r
= ret
= kernel_recvmsg(con
->sock
, &msg
, iov
, nvec
, len
,
626 MSG_DONTWAIT
| MSG_NOSIGNAL
);
630 /* Process SCTP notifications */
631 if (msg
.msg_flags
& MSG_NOTIFICATION
) {
632 msg
.msg_control
= incmsg
;
633 msg
.msg_controllen
= sizeof(incmsg
);
635 process_sctp_notification(con
, &msg
,
636 page_address(con
->rx_page
) + con
->cb
.base
);
637 mutex_unlock(&con
->sock_mutex
);
640 BUG_ON(con
->nodeid
== 0);
644 cbuf_add(&con
->cb
, ret
);
645 ret
= dlm_process_incoming_buffer(con
->nodeid
,
646 page_address(con
->rx_page
),
647 con
->cb
.base
, con
->cb
.len
,
649 if (ret
== -EBADMSG
) {
650 log_print("lowcomms: addr=%p, base=%u, len=%u, "
651 "iov_len=%u, iov_base[0]=%p, read=%d",
652 page_address(con
->rx_page
), con
->cb
.base
, con
->cb
.len
,
653 len
, iov
[0].iov_base
, r
);
657 cbuf_eat(&con
->cb
, ret
);
659 if (cbuf_empty(&con
->cb
) && !call_again_soon
) {
660 __free_page(con
->rx_page
);
666 mutex_unlock(&con
->sock_mutex
);
670 if (!test_and_set_bit(CF_READ_PENDING
, &con
->flags
))
671 queue_work(recv_workqueue
, &con
->rwork
);
672 mutex_unlock(&con
->sock_mutex
);
676 mutex_unlock(&con
->sock_mutex
);
677 if (ret
!= -EAGAIN
) {
678 close_connection(con
, false);
679 /* Reconnect when there is something to send */
681 /* Don't return success if we really got EOF */
688 /* Listening socket is busy, accept a connection */
689 static int tcp_accept_from_sock(struct connection
*con
)
692 struct sockaddr_storage peeraddr
;
693 struct socket
*newsock
;
696 struct connection
*newcon
;
697 struct connection
*addcon
;
699 memset(&peeraddr
, 0, sizeof(peeraddr
));
700 result
= sock_create_kern(dlm_local_addr
[0]->ss_family
, SOCK_STREAM
,
701 IPPROTO_TCP
, &newsock
);
705 mutex_lock_nested(&con
->sock_mutex
, 0);
708 if (con
->sock
== NULL
)
711 newsock
->type
= con
->sock
->type
;
712 newsock
->ops
= con
->sock
->ops
;
714 result
= con
->sock
->ops
->accept(con
->sock
, newsock
, O_NONBLOCK
);
718 /* Get the connected socket's peer */
719 memset(&peeraddr
, 0, sizeof(peeraddr
));
720 if (newsock
->ops
->getname(newsock
, (struct sockaddr
*)&peeraddr
,
722 result
= -ECONNABORTED
;
726 /* Get the new node's NODEID */
727 make_sockaddr(&peeraddr
, 0, &len
);
728 if (dlm_addr_to_nodeid(&peeraddr
, &nodeid
)) {
729 log_print("connect from non cluster node");
730 sock_release(newsock
);
731 mutex_unlock(&con
->sock_mutex
);
735 log_print("got connection from %d", nodeid
);
737 /* Check to see if we already have a connection to this node. This
738 * could happen if the two nodes initiate a connection at roughly
739 * the same time and the connections cross on the wire.
740 * In this case we store the incoming one in "othercon"
742 newcon
= nodeid2con(nodeid
, GFP_NOFS
);
747 mutex_lock_nested(&newcon
->sock_mutex
, 1);
749 struct connection
*othercon
= newcon
->othercon
;
752 othercon
= kmem_cache_zalloc(con_cache
, GFP_NOFS
);
754 log_print("failed to allocate incoming socket");
755 mutex_unlock(&newcon
->sock_mutex
);
759 othercon
->nodeid
= nodeid
;
760 othercon
->rx_action
= receive_from_sock
;
761 mutex_init(&othercon
->sock_mutex
);
762 INIT_WORK(&othercon
->swork
, process_send_sockets
);
763 INIT_WORK(&othercon
->rwork
, process_recv_sockets
);
764 set_bit(CF_IS_OTHERCON
, &othercon
->flags
);
766 if (!othercon
->sock
) {
767 newcon
->othercon
= othercon
;
768 othercon
->sock
= newsock
;
769 newsock
->sk
->sk_user_data
= othercon
;
770 add_sock(newsock
, othercon
);
774 printk("Extra connection from node %d attempted\n", nodeid
);
776 mutex_unlock(&newcon
->sock_mutex
);
781 newsock
->sk
->sk_user_data
= newcon
;
782 newcon
->rx_action
= receive_from_sock
;
783 add_sock(newsock
, newcon
);
787 mutex_unlock(&newcon
->sock_mutex
);
790 * Add it to the active queue in case we got data
791 * beween processing the accept adding the socket
792 * to the read_sockets list
794 if (!test_and_set_bit(CF_READ_PENDING
, &addcon
->flags
))
795 queue_work(recv_workqueue
, &addcon
->rwork
);
796 mutex_unlock(&con
->sock_mutex
);
801 mutex_unlock(&con
->sock_mutex
);
802 sock_release(newsock
);
804 if (result
!= -EAGAIN
)
805 log_print("error accepting connection from node: %d", result
);
809 static void free_entry(struct writequeue_entry
*e
)
811 __free_page(e
->page
);
815 /* Initiate an SCTP association.
816 This is a special case of send_to_sock() in that we don't yet have a
817 peeled-off socket for this association, so we use the listening socket
818 and add the primary IP address of the remote node.
820 static void sctp_init_assoc(struct connection
*con
)
822 struct sockaddr_storage rem_addr
;
823 char outcmsg
[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo
))];
824 struct msghdr outmessage
;
825 struct cmsghdr
*cmsg
;
826 struct sctp_sndrcvinfo
*sinfo
;
827 struct connection
*base_con
;
828 struct writequeue_entry
*e
;
834 if (test_and_set_bit(CF_INIT_PENDING
, &con
->flags
))
837 if (con
->retries
++ > MAX_CONNECT_RETRIES
)
840 log_print("Initiating association with node %d", con
->nodeid
);
842 if (nodeid_to_addr(con
->nodeid
, (struct sockaddr
*)&rem_addr
)) {
843 log_print("no address for nodeid %d", con
->nodeid
);
846 base_con
= nodeid2con(0, 0);
847 BUG_ON(base_con
== NULL
);
849 make_sockaddr(&rem_addr
, dlm_config
.ci_tcp_port
, &addrlen
);
851 outmessage
.msg_name
= &rem_addr
;
852 outmessage
.msg_namelen
= addrlen
;
853 outmessage
.msg_control
= outcmsg
;
854 outmessage
.msg_controllen
= sizeof(outcmsg
);
855 outmessage
.msg_flags
= MSG_EOR
;
857 spin_lock(&con
->writequeue_lock
);
858 e
= list_entry(con
->writequeue
.next
, struct writequeue_entry
,
861 BUG_ON((struct list_head
*) e
== &con
->writequeue
);
865 spin_unlock(&con
->writequeue_lock
);
867 /* Send the first block off the write queue */
868 iov
[0].iov_base
= page_address(e
->page
)+offset
;
869 iov
[0].iov_len
= len
;
871 cmsg
= CMSG_FIRSTHDR(&outmessage
);
872 cmsg
->cmsg_level
= IPPROTO_SCTP
;
873 cmsg
->cmsg_type
= SCTP_SNDRCV
;
874 cmsg
->cmsg_len
= CMSG_LEN(sizeof(struct sctp_sndrcvinfo
));
875 sinfo
= CMSG_DATA(cmsg
);
876 memset(sinfo
, 0x00, sizeof(struct sctp_sndrcvinfo
));
877 sinfo
->sinfo_ppid
= cpu_to_le32(dlm_our_nodeid());
878 outmessage
.msg_controllen
= cmsg
->cmsg_len
;
880 ret
= kernel_sendmsg(base_con
->sock
, &outmessage
, iov
, 1, len
);
882 log_print("Send first packet to node %d failed: %d",
885 /* Try again later */
886 clear_bit(CF_CONNECT_PENDING
, &con
->flags
);
887 clear_bit(CF_INIT_PENDING
, &con
->flags
);
890 spin_lock(&con
->writequeue_lock
);
894 if (e
->len
== 0 && e
->users
== 0) {
898 spin_unlock(&con
->writequeue_lock
);
902 /* Connect a new socket to its peer */
903 static void tcp_connect_to_sock(struct connection
*con
)
905 int result
= -EHOSTUNREACH
;
906 struct sockaddr_storage saddr
, src_addr
;
908 struct socket
*sock
= NULL
;
910 if (con
->nodeid
== 0) {
911 log_print("attempt to connect sock 0 foiled");
915 mutex_lock(&con
->sock_mutex
);
916 if (con
->retries
++ > MAX_CONNECT_RETRIES
)
919 /* Some odd races can cause double-connects, ignore them */
925 /* Create a socket to communicate with */
926 result
= sock_create_kern(dlm_local_addr
[0]->ss_family
, SOCK_STREAM
,
931 memset(&saddr
, 0, sizeof(saddr
));
932 if (dlm_nodeid_to_addr(con
->nodeid
, &saddr
))
935 sock
->sk
->sk_user_data
= con
;
936 con
->rx_action
= receive_from_sock
;
937 con
->connect_action
= tcp_connect_to_sock
;
940 /* Bind to our cluster-known address connecting to avoid
942 memcpy(&src_addr
, dlm_local_addr
[0], sizeof(src_addr
));
943 make_sockaddr(&src_addr
, 0, &addr_len
);
944 result
= sock
->ops
->bind(sock
, (struct sockaddr
*) &src_addr
,
947 log_print("could not bind for connect: %d", result
);
948 /* This *may* not indicate a critical error */
951 make_sockaddr(&saddr
, dlm_config
.ci_tcp_port
, &addr_len
);
953 log_print("connecting to %d", con
->nodeid
);
955 sock
->ops
->connect(sock
, (struct sockaddr
*)&saddr
, addr_len
,
957 if (result
== -EINPROGRESS
)
964 sock_release(con
->sock
);
970 * Some errors are fatal and this list might need adjusting. For other
971 * errors we try again until the max number of retries is reached.
973 if (result
!= -EHOSTUNREACH
&& result
!= -ENETUNREACH
&&
974 result
!= -ENETDOWN
&& result
!= -EINVAL
975 && result
!= -EPROTONOSUPPORT
) {
976 lowcomms_connect_sock(con
);
980 mutex_unlock(&con
->sock_mutex
);
984 static struct socket
*tcp_create_listen_sock(struct connection
*con
,
985 struct sockaddr_storage
*saddr
)
987 struct socket
*sock
= NULL
;
992 if (dlm_local_addr
[0]->ss_family
== AF_INET
)
993 addr_len
= sizeof(struct sockaddr_in
);
995 addr_len
= sizeof(struct sockaddr_in6
);
997 /* Create a socket to communicate with */
998 result
= sock_create_kern(dlm_local_addr
[0]->ss_family
, SOCK_STREAM
,
1001 log_print("Can't create listening comms socket");
1005 result
= kernel_setsockopt(sock
, SOL_SOCKET
, SO_REUSEADDR
,
1006 (char *)&one
, sizeof(one
));
1009 log_print("Failed to set SO_REUSEADDR on socket: %d", result
);
1011 sock
->sk
->sk_user_data
= con
;
1012 con
->rx_action
= tcp_accept_from_sock
;
1013 con
->connect_action
= tcp_connect_to_sock
;
1016 /* Bind to our port */
1017 make_sockaddr(saddr
, dlm_config
.ci_tcp_port
, &addr_len
);
1018 result
= sock
->ops
->bind(sock
, (struct sockaddr
*) saddr
, addr_len
);
1020 log_print("Can't bind to port %d", dlm_config
.ci_tcp_port
);
1026 result
= kernel_setsockopt(sock
, SOL_SOCKET
, SO_KEEPALIVE
,
1027 (char *)&one
, sizeof(one
));
1029 log_print("Set keepalive failed: %d", result
);
1032 result
= sock
->ops
->listen(sock
, 5);
1034 log_print("Can't listen on port %d", dlm_config
.ci_tcp_port
);
1044 /* Get local addresses */
1045 static void init_local(void)
1047 struct sockaddr_storage sas
, *addr
;
1050 dlm_local_count
= 0;
1051 for (i
= 0; i
< DLM_MAX_ADDR_COUNT
- 1; i
++) {
1052 if (dlm_our_addr(&sas
, i
))
1055 addr
= kmalloc(sizeof(*addr
), GFP_KERNEL
);
1058 memcpy(addr
, &sas
, sizeof(*addr
));
1059 dlm_local_addr
[dlm_local_count
++] = addr
;
1063 /* Bind to an IP address. SCTP allows multiple address so it can do
1065 static int add_sctp_bind_addr(struct connection
*sctp_con
,
1066 struct sockaddr_storage
*addr
,
1067 int addr_len
, int num
)
1072 result
= kernel_bind(sctp_con
->sock
,
1073 (struct sockaddr
*) addr
,
1076 result
= kernel_setsockopt(sctp_con
->sock
, SOL_SCTP
,
1077 SCTP_SOCKOPT_BINDX_ADD
,
1078 (char *)addr
, addr_len
);
1081 log_print("Can't bind to port %d addr number %d",
1082 dlm_config
.ci_tcp_port
, num
);
1087 /* Initialise SCTP socket and bind to all interfaces */
1088 static int sctp_listen_for_all(void)
1090 struct socket
*sock
= NULL
;
1091 struct sockaddr_storage localaddr
;
1092 struct sctp_event_subscribe subscribe
;
1093 int result
= -EINVAL
, num
= 1, i
, addr_len
;
1094 struct connection
*con
= nodeid2con(0, GFP_KERNEL
);
1095 int bufsize
= NEEDED_RMEM
;
1100 log_print("Using SCTP for communications");
1102 result
= sock_create_kern(dlm_local_addr
[0]->ss_family
, SOCK_SEQPACKET
,
1103 IPPROTO_SCTP
, &sock
);
1105 log_print("Can't create comms socket, check SCTP is loaded");
1109 /* Listen for events */
1110 memset(&subscribe
, 0, sizeof(subscribe
));
1111 subscribe
.sctp_data_io_event
= 1;
1112 subscribe
.sctp_association_event
= 1;
1113 subscribe
.sctp_send_failure_event
= 1;
1114 subscribe
.sctp_shutdown_event
= 1;
1115 subscribe
.sctp_partial_delivery_event
= 1;
1117 result
= kernel_setsockopt(sock
, SOL_SOCKET
, SO_RCVBUFFORCE
,
1118 (char *)&bufsize
, sizeof(bufsize
));
1120 log_print("Error increasing buffer space on socket %d", result
);
1122 result
= kernel_setsockopt(sock
, SOL_SCTP
, SCTP_EVENTS
,
1123 (char *)&subscribe
, sizeof(subscribe
));
1125 log_print("Failed to set SCTP_EVENTS on socket: result=%d",
1127 goto create_delsock
;
1130 /* Init con struct */
1131 sock
->sk
->sk_user_data
= con
;
1133 con
->sock
->sk
->sk_data_ready
= lowcomms_data_ready
;
1134 con
->rx_action
= receive_from_sock
;
1135 con
->connect_action
= sctp_init_assoc
;
1137 /* Bind to all interfaces. */
1138 for (i
= 0; i
< dlm_local_count
; i
++) {
1139 memcpy(&localaddr
, dlm_local_addr
[i
], sizeof(localaddr
));
1140 make_sockaddr(&localaddr
, dlm_config
.ci_tcp_port
, &addr_len
);
1142 result
= add_sctp_bind_addr(con
, &localaddr
, addr_len
, num
);
1144 goto create_delsock
;
1148 result
= sock
->ops
->listen(sock
, 5);
1150 log_print("Can't set socket listening");
1151 goto create_delsock
;
1163 static int tcp_listen_for_all(void)
1165 struct socket
*sock
= NULL
;
1166 struct connection
*con
= nodeid2con(0, GFP_KERNEL
);
1167 int result
= -EINVAL
;
1172 /* We don't support multi-homed hosts */
1173 if (dlm_local_addr
[1] != NULL
) {
1174 log_print("TCP protocol can't handle multi-homed hosts, "
1179 log_print("Using TCP for communications");
1181 sock
= tcp_create_listen_sock(con
, dlm_local_addr
[0]);
1183 add_sock(sock
, con
);
1187 result
= -EADDRINUSE
;
1195 static struct writequeue_entry
*new_writequeue_entry(struct connection
*con
,
1198 struct writequeue_entry
*entry
;
1200 entry
= kmalloc(sizeof(struct writequeue_entry
), allocation
);
1204 entry
->page
= alloc_page(allocation
);
1219 void *dlm_lowcomms_get_buffer(int nodeid
, int len
, gfp_t allocation
, char **ppc
)
1221 struct connection
*con
;
1222 struct writequeue_entry
*e
;
1226 con
= nodeid2con(nodeid
, allocation
);
1230 spin_lock(&con
->writequeue_lock
);
1231 e
= list_entry(con
->writequeue
.prev
, struct writequeue_entry
, list
);
1232 if ((&e
->list
== &con
->writequeue
) ||
1233 (PAGE_CACHE_SIZE
- e
->end
< len
)) {
1240 spin_unlock(&con
->writequeue_lock
);
1244 *ppc
= page_address(e
->page
) + offset
;
1248 e
= new_writequeue_entry(con
, allocation
);
1250 spin_lock(&con
->writequeue_lock
);
1254 list_add_tail(&e
->list
, &con
->writequeue
);
1255 spin_unlock(&con
->writequeue_lock
);
1261 void dlm_lowcomms_commit_buffer(void *mh
)
1263 struct writequeue_entry
*e
= (struct writequeue_entry
*)mh
;
1264 struct connection
*con
= e
->con
;
1267 spin_lock(&con
->writequeue_lock
);
1271 e
->len
= e
->end
- e
->offset
;
1272 spin_unlock(&con
->writequeue_lock
);
1274 if (!test_and_set_bit(CF_WRITE_PENDING
, &con
->flags
)) {
1275 queue_work(send_workqueue
, &con
->swork
);
1280 spin_unlock(&con
->writequeue_lock
);
1284 /* Send a message */
1285 static void send_to_sock(struct connection
*con
)
1288 const int msg_flags
= MSG_DONTWAIT
| MSG_NOSIGNAL
;
1289 struct writequeue_entry
*e
;
1292 mutex_lock(&con
->sock_mutex
);
1293 if (con
->sock
== NULL
)
1296 spin_lock(&con
->writequeue_lock
);
1298 e
= list_entry(con
->writequeue
.next
, struct writequeue_entry
,
1300 if ((struct list_head
*) e
== &con
->writequeue
)
1305 BUG_ON(len
== 0 && e
->users
== 0);
1306 spin_unlock(&con
->writequeue_lock
);
1310 ret
= kernel_sendpage(con
->sock
, e
->page
, offset
, len
,
1312 if (ret
== -EAGAIN
|| ret
== 0) {
1319 /* Don't starve people filling buffers */
1322 spin_lock(&con
->writequeue_lock
);
1326 if (e
->len
== 0 && e
->users
== 0) {
1332 spin_unlock(&con
->writequeue_lock
);
1334 mutex_unlock(&con
->sock_mutex
);
1338 mutex_unlock(&con
->sock_mutex
);
1339 close_connection(con
, false);
1340 lowcomms_connect_sock(con
);
1344 mutex_unlock(&con
->sock_mutex
);
1345 if (!test_bit(CF_INIT_PENDING
, &con
->flags
))
1346 lowcomms_connect_sock(con
);
1350 static void clean_one_writequeue(struct connection
*con
)
1352 struct writequeue_entry
*e
, *safe
;
1354 spin_lock(&con
->writequeue_lock
);
1355 list_for_each_entry_safe(e
, safe
, &con
->writequeue
, list
) {
1359 spin_unlock(&con
->writequeue_lock
);
1362 /* Called from recovery when it knows that a node has
1364 int dlm_lowcomms_close(int nodeid
)
1366 struct connection
*con
;
1368 log_print("closing connection to node %d", nodeid
);
1369 con
= nodeid2con(nodeid
, 0);
1371 clear_bit(CF_CONNECT_PENDING
, &con
->flags
);
1372 clear_bit(CF_WRITE_PENDING
, &con
->flags
);
1373 set_bit(CF_CLOSE
, &con
->flags
);
1374 if (cancel_work_sync(&con
->swork
))
1375 log_print("canceled swork for node %d", nodeid
);
1376 if (cancel_work_sync(&con
->rwork
))
1377 log_print("canceled rwork for node %d", nodeid
);
1378 clean_one_writequeue(con
);
1379 close_connection(con
, true);
1384 /* Receive workqueue function */
1385 static void process_recv_sockets(struct work_struct
*work
)
1387 struct connection
*con
= container_of(work
, struct connection
, rwork
);
1390 clear_bit(CF_READ_PENDING
, &con
->flags
);
1392 err
= con
->rx_action(con
);
1396 /* Send workqueue function */
1397 static void process_send_sockets(struct work_struct
*work
)
1399 struct connection
*con
= container_of(work
, struct connection
, swork
);
1401 if (test_and_clear_bit(CF_CONNECT_PENDING
, &con
->flags
)) {
1402 con
->connect_action(con
);
1403 set_bit(CF_WRITE_PENDING
, &con
->flags
);
1405 if (test_and_clear_bit(CF_WRITE_PENDING
, &con
->flags
))
1410 /* Discard all entries on the write queues */
1411 static void clean_writequeues(void)
1413 foreach_conn(clean_one_writequeue
);
1416 static void work_stop(void)
1418 destroy_workqueue(recv_workqueue
);
1419 destroy_workqueue(send_workqueue
);
1422 static int work_start(void)
1425 recv_workqueue
= create_workqueue("dlm_recv");
1426 error
= IS_ERR(recv_workqueue
);
1428 log_print("can't start dlm_recv %d", error
);
1432 send_workqueue
= create_singlethread_workqueue("dlm_send");
1433 error
= IS_ERR(send_workqueue
);
1435 log_print("can't start dlm_send %d", error
);
1436 destroy_workqueue(recv_workqueue
);
1443 static void stop_conn(struct connection
*con
)
1446 if (con
->sock
&& con
->sock
->sk
)
1447 con
->sock
->sk
->sk_user_data
= NULL
;
1450 static void free_conn(struct connection
*con
)
1452 close_connection(con
, true);
1454 kmem_cache_free(con_cache
, con
->othercon
);
1455 hlist_del(&con
->list
);
1456 kmem_cache_free(con_cache
, con
);
1459 void dlm_lowcomms_stop(void)
1461 /* Set all the flags to prevent any
1464 mutex_lock(&connections_lock
);
1465 foreach_conn(stop_conn
);
1466 mutex_unlock(&connections_lock
);
1470 mutex_lock(&connections_lock
);
1471 clean_writequeues();
1473 foreach_conn(free_conn
);
1475 mutex_unlock(&connections_lock
);
1476 kmem_cache_destroy(con_cache
);
1479 int dlm_lowcomms_start(void)
1481 int error
= -EINVAL
;
1482 struct connection
*con
;
1485 for (i
= 0; i
< CONN_HASH_SIZE
; i
++)
1486 INIT_HLIST_HEAD(&connection_hash
[i
]);
1489 if (!dlm_local_count
) {
1491 log_print("no local IP address has been set");
1496 con_cache
= kmem_cache_create("dlm_conn", sizeof(struct connection
),
1497 __alignof__(struct connection
), 0,
1502 /* Start listening */
1503 if (dlm_config
.ci_protocol
== 0)
1504 error
= tcp_listen_for_all();
1506 error
= sctp_listen_for_all();
1510 error
= work_start();
1517 con
= nodeid2con(0,0);
1519 close_connection(con
, false);
1520 kmem_cache_free(con_cache
, con
);
1522 kmem_cache_destroy(con_cache
);