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 <linux/slab.h>
55 #include <net/sctp/sctp.h>
56 #include <net/sctp/user.h>
59 #include "dlm_internal.h"
64 #define NEEDED_RMEM (4*1024*1024)
65 #define CONN_HASH_SIZE 32
67 /* Number of messages to send before rescheduling */
68 #define MAX_SEND_MSG_COUNT 25
76 static void cbuf_add(struct cbuf
*cb
, int n
)
81 static int cbuf_data(struct cbuf
*cb
)
83 return ((cb
->base
+ cb
->len
) & cb
->mask
);
86 static void cbuf_init(struct cbuf
*cb
, int size
)
88 cb
->base
= cb
->len
= 0;
92 static void cbuf_eat(struct cbuf
*cb
, int n
)
99 static bool cbuf_empty(struct cbuf
*cb
)
105 struct socket
*sock
; /* NULL if not connected */
106 uint32_t nodeid
; /* So we know who we are in the list */
107 struct mutex sock_mutex
;
109 #define CF_READ_PENDING 1
110 #define CF_WRITE_PENDING 2
111 #define CF_CONNECT_PENDING 3
112 #define CF_INIT_PENDING 4
113 #define CF_IS_OTHERCON 5
115 #define CF_APP_LIMITED 7
116 struct list_head writequeue
; /* List of outgoing writequeue_entries */
117 spinlock_t writequeue_lock
;
118 int (*rx_action
) (struct connection
*); /* What to do when active */
119 void (*connect_action
) (struct connection
*); /* What to do to connect */
120 struct page
*rx_page
;
123 #define MAX_CONNECT_RETRIES 3
125 struct hlist_node list
;
126 struct connection
*othercon
;
127 struct work_struct rwork
; /* Receive workqueue */
128 struct work_struct swork
; /* Send workqueue */
130 #define sock2con(x) ((struct connection *)(x)->sk_user_data)
132 /* An entry waiting to be sent */
133 struct writequeue_entry
{
134 struct list_head list
;
140 struct connection
*con
;
143 static struct sockaddr_storage
*dlm_local_addr
[DLM_MAX_ADDR_COUNT
];
144 static int dlm_local_count
;
147 static struct workqueue_struct
*recv_workqueue
;
148 static struct workqueue_struct
*send_workqueue
;
150 static struct hlist_head connection_hash
[CONN_HASH_SIZE
];
151 static DEFINE_MUTEX(connections_lock
);
152 static struct kmem_cache
*con_cache
;
154 static void process_recv_sockets(struct work_struct
*work
);
155 static void process_send_sockets(struct work_struct
*work
);
158 /* This is deliberately very simple because most clusters have simple
159 sequential nodeids, so we should be able to go straight to a connection
160 struct in the array */
161 static inline int nodeid_hash(int nodeid
)
163 return nodeid
& (CONN_HASH_SIZE
-1);
166 static struct connection
*__find_con(int nodeid
)
169 struct hlist_node
*h
;
170 struct connection
*con
;
172 r
= nodeid_hash(nodeid
);
174 hlist_for_each_entry(con
, h
, &connection_hash
[r
], list
) {
175 if (con
->nodeid
== nodeid
)
182 * If 'allocation' is zero then we don't attempt to create a new
183 * connection structure for this node.
185 static struct connection
*__nodeid2con(int nodeid
, gfp_t alloc
)
187 struct connection
*con
= NULL
;
190 con
= __find_con(nodeid
);
194 con
= kmem_cache_zalloc(con_cache
, alloc
);
198 r
= nodeid_hash(nodeid
);
199 hlist_add_head(&con
->list
, &connection_hash
[r
]);
201 con
->nodeid
= nodeid
;
202 mutex_init(&con
->sock_mutex
);
203 INIT_LIST_HEAD(&con
->writequeue
);
204 spin_lock_init(&con
->writequeue_lock
);
205 INIT_WORK(&con
->swork
, process_send_sockets
);
206 INIT_WORK(&con
->rwork
, process_recv_sockets
);
208 /* Setup action pointers for child sockets */
210 struct connection
*zerocon
= __find_con(0);
212 con
->connect_action
= zerocon
->connect_action
;
214 con
->rx_action
= zerocon
->rx_action
;
220 /* Loop round all connections */
221 static void foreach_conn(void (*conn_func
)(struct connection
*c
))
224 struct hlist_node
*h
, *n
;
225 struct connection
*con
;
227 for (i
= 0; i
< CONN_HASH_SIZE
; i
++) {
228 hlist_for_each_entry_safe(con
, h
, n
, &connection_hash
[i
], list
){
234 static struct connection
*nodeid2con(int nodeid
, gfp_t allocation
)
236 struct connection
*con
;
238 mutex_lock(&connections_lock
);
239 con
= __nodeid2con(nodeid
, allocation
);
240 mutex_unlock(&connections_lock
);
245 /* This is a bit drastic, but only called when things go wrong */
246 static struct connection
*assoc2con(int assoc_id
)
249 struct hlist_node
*h
;
250 struct connection
*con
;
252 mutex_lock(&connections_lock
);
254 for (i
= 0 ; i
< CONN_HASH_SIZE
; i
++) {
255 hlist_for_each_entry(con
, h
, &connection_hash
[i
], list
) {
256 if (con
->sctp_assoc
== assoc_id
) {
257 mutex_unlock(&connections_lock
);
262 mutex_unlock(&connections_lock
);
266 static int nodeid_to_addr(int nodeid
, struct sockaddr
*retaddr
)
268 struct sockaddr_storage addr
;
271 if (!dlm_local_count
)
274 error
= dlm_nodeid_to_addr(nodeid
, &addr
);
278 if (dlm_local_addr
[0]->ss_family
== AF_INET
) {
279 struct sockaddr_in
*in4
= (struct sockaddr_in
*) &addr
;
280 struct sockaddr_in
*ret4
= (struct sockaddr_in
*) retaddr
;
281 ret4
->sin_addr
.s_addr
= in4
->sin_addr
.s_addr
;
283 struct sockaddr_in6
*in6
= (struct sockaddr_in6
*) &addr
;
284 struct sockaddr_in6
*ret6
= (struct sockaddr_in6
*) retaddr
;
285 ret6
->sin6_addr
= in6
->sin6_addr
;
291 /* Data available on socket or listen socket received a connect */
292 static void lowcomms_data_ready(struct sock
*sk
, int count_unused
)
294 struct connection
*con
= sock2con(sk
);
295 if (con
&& !test_and_set_bit(CF_READ_PENDING
, &con
->flags
))
296 queue_work(recv_workqueue
, &con
->rwork
);
299 static void lowcomms_write_space(struct sock
*sk
)
301 struct connection
*con
= sock2con(sk
);
306 clear_bit(SOCK_NOSPACE
, &con
->sock
->flags
);
308 if (test_and_clear_bit(CF_APP_LIMITED
, &con
->flags
)) {
309 con
->sock
->sk
->sk_write_pending
--;
310 clear_bit(SOCK_ASYNC_NOSPACE
, &con
->sock
->flags
);
313 if (!test_and_set_bit(CF_WRITE_PENDING
, &con
->flags
))
314 queue_work(send_workqueue
, &con
->swork
);
317 static inline void lowcomms_connect_sock(struct connection
*con
)
319 if (test_bit(CF_CLOSE
, &con
->flags
))
321 if (!test_and_set_bit(CF_CONNECT_PENDING
, &con
->flags
))
322 queue_work(send_workqueue
, &con
->swork
);
325 static void lowcomms_state_change(struct sock
*sk
)
327 if (sk
->sk_state
== TCP_ESTABLISHED
)
328 lowcomms_write_space(sk
);
331 int dlm_lowcomms_connect_node(int nodeid
)
333 struct connection
*con
;
335 /* with sctp there's no connecting without sending */
336 if (dlm_config
.ci_protocol
!= 0)
339 if (nodeid
== dlm_our_nodeid())
342 con
= nodeid2con(nodeid
, GFP_NOFS
);
345 lowcomms_connect_sock(con
);
349 /* Make a socket active */
350 static int add_sock(struct socket
*sock
, struct connection
*con
)
354 /* Install a data_ready callback */
355 con
->sock
->sk
->sk_data_ready
= lowcomms_data_ready
;
356 con
->sock
->sk
->sk_write_space
= lowcomms_write_space
;
357 con
->sock
->sk
->sk_state_change
= lowcomms_state_change
;
358 con
->sock
->sk
->sk_user_data
= con
;
359 con
->sock
->sk
->sk_allocation
= GFP_NOFS
;
363 /* Add the port number to an IPv6 or 4 sockaddr and return the address
365 static void make_sockaddr(struct sockaddr_storage
*saddr
, uint16_t port
,
368 saddr
->ss_family
= dlm_local_addr
[0]->ss_family
;
369 if (saddr
->ss_family
== AF_INET
) {
370 struct sockaddr_in
*in4_addr
= (struct sockaddr_in
*)saddr
;
371 in4_addr
->sin_port
= cpu_to_be16(port
);
372 *addr_len
= sizeof(struct sockaddr_in
);
373 memset(&in4_addr
->sin_zero
, 0, sizeof(in4_addr
->sin_zero
));
375 struct sockaddr_in6
*in6_addr
= (struct sockaddr_in6
*)saddr
;
376 in6_addr
->sin6_port
= cpu_to_be16(port
);
377 *addr_len
= sizeof(struct sockaddr_in6
);
379 memset((char *)saddr
+ *addr_len
, 0, sizeof(struct sockaddr_storage
) - *addr_len
);
382 /* Close a remote connection and tidy up */
383 static void close_connection(struct connection
*con
, bool and_other
)
385 mutex_lock(&con
->sock_mutex
);
388 sock_release(con
->sock
);
391 if (con
->othercon
&& and_other
) {
392 /* Will only re-enter once. */
393 close_connection(con
->othercon
, false);
396 __free_page(con
->rx_page
);
401 mutex_unlock(&con
->sock_mutex
);
404 /* We only send shutdown messages to nodes that are not part of the cluster */
405 static void sctp_send_shutdown(sctp_assoc_t associd
)
407 static char outcmsg
[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo
))];
408 struct msghdr outmessage
;
409 struct cmsghdr
*cmsg
;
410 struct sctp_sndrcvinfo
*sinfo
;
412 struct connection
*con
;
414 con
= nodeid2con(0,0);
417 outmessage
.msg_name
= NULL
;
418 outmessage
.msg_namelen
= 0;
419 outmessage
.msg_control
= outcmsg
;
420 outmessage
.msg_controllen
= sizeof(outcmsg
);
421 outmessage
.msg_flags
= MSG_EOR
;
423 cmsg
= CMSG_FIRSTHDR(&outmessage
);
424 cmsg
->cmsg_level
= IPPROTO_SCTP
;
425 cmsg
->cmsg_type
= SCTP_SNDRCV
;
426 cmsg
->cmsg_len
= CMSG_LEN(sizeof(struct sctp_sndrcvinfo
));
427 outmessage
.msg_controllen
= cmsg
->cmsg_len
;
428 sinfo
= CMSG_DATA(cmsg
);
429 memset(sinfo
, 0x00, sizeof(struct sctp_sndrcvinfo
));
431 sinfo
->sinfo_flags
|= MSG_EOF
;
432 sinfo
->sinfo_assoc_id
= associd
;
434 ret
= kernel_sendmsg(con
->sock
, &outmessage
, NULL
, 0, 0);
437 log_print("send EOF to node failed: %d", ret
);
440 static void sctp_init_failed_foreach(struct connection
*con
)
443 if (test_and_clear_bit(CF_CONNECT_PENDING
, &con
->flags
)) {
444 if (!test_and_set_bit(CF_WRITE_PENDING
, &con
->flags
))
445 queue_work(send_workqueue
, &con
->swork
);
449 /* INIT failed but we don't know which node...
450 restart INIT on all pending nodes */
451 static void sctp_init_failed(void)
453 mutex_lock(&connections_lock
);
455 foreach_conn(sctp_init_failed_foreach
);
457 mutex_unlock(&connections_lock
);
460 /* Something happened to an association */
461 static void process_sctp_notification(struct connection
*con
,
462 struct msghdr
*msg
, char *buf
)
464 union sctp_notification
*sn
= (union sctp_notification
*)buf
;
466 if (sn
->sn_header
.sn_type
== SCTP_ASSOC_CHANGE
) {
467 switch (sn
->sn_assoc_change
.sac_state
) {
472 /* Check that the new node is in the lockspace */
473 struct sctp_prim prim
;
477 struct connection
*new_con
;
480 * We get this before any data for an association.
481 * We verify that the node is in the cluster and
482 * then peel off a socket for it.
484 if ((int)sn
->sn_assoc_change
.sac_assoc_id
<= 0) {
485 log_print("COMM_UP for invalid assoc ID %d",
486 (int)sn
->sn_assoc_change
.sac_assoc_id
);
490 memset(&prim
, 0, sizeof(struct sctp_prim
));
491 prim_len
= sizeof(struct sctp_prim
);
492 prim
.ssp_assoc_id
= sn
->sn_assoc_change
.sac_assoc_id
;
494 ret
= kernel_getsockopt(con
->sock
,
500 log_print("getsockopt/sctp_primary_addr on "
501 "new assoc %d failed : %d",
502 (int)sn
->sn_assoc_change
.sac_assoc_id
,
505 /* Retry INIT later */
506 new_con
= assoc2con(sn
->sn_assoc_change
.sac_assoc_id
);
508 clear_bit(CF_CONNECT_PENDING
, &con
->flags
);
511 make_sockaddr(&prim
.ssp_addr
, 0, &addr_len
);
512 if (dlm_addr_to_nodeid(&prim
.ssp_addr
, &nodeid
)) {
513 unsigned char *b
=(unsigned char *)&prim
.ssp_addr
;
514 log_print("reject connect from unknown addr");
515 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE
,
516 b
, sizeof(struct sockaddr_storage
));
517 sctp_send_shutdown(prim
.ssp_assoc_id
);
521 new_con
= nodeid2con(nodeid
, GFP_NOFS
);
525 /* Peel off a new sock */
526 sctp_lock_sock(con
->sock
->sk
);
527 ret
= sctp_do_peeloff(con
->sock
->sk
,
528 sn
->sn_assoc_change
.sac_assoc_id
,
530 sctp_release_sock(con
->sock
->sk
);
532 log_print("Can't peel off a socket for "
533 "connection %d to node %d: err=%d",
534 (int)sn
->sn_assoc_change
.sac_assoc_id
,
538 add_sock(new_con
->sock
, new_con
);
540 log_print("connecting to %d sctp association %d",
541 nodeid
, (int)sn
->sn_assoc_change
.sac_assoc_id
);
543 /* Send any pending writes */
544 clear_bit(CF_CONNECT_PENDING
, &new_con
->flags
);
545 clear_bit(CF_INIT_PENDING
, &con
->flags
);
546 if (!test_and_set_bit(CF_WRITE_PENDING
, &new_con
->flags
)) {
547 queue_work(send_workqueue
, &new_con
->swork
);
549 if (!test_and_set_bit(CF_READ_PENDING
, &new_con
->flags
))
550 queue_work(recv_workqueue
, &new_con
->rwork
);
555 case SCTP_SHUTDOWN_COMP
:
557 con
= assoc2con(sn
->sn_assoc_change
.sac_assoc_id
);
564 /* We don't know which INIT failed, so clear the PENDING flags
565 * on them all. if assoc_id is zero then it will then try
568 case SCTP_CANT_STR_ASSOC
:
570 log_print("Can't start SCTP association - retrying");
576 log_print("unexpected SCTP assoc change id=%d state=%d",
577 (int)sn
->sn_assoc_change
.sac_assoc_id
,
578 sn
->sn_assoc_change
.sac_state
);
583 /* Data received from remote end */
584 static int receive_from_sock(struct connection
*con
)
587 struct msghdr msg
= {};
591 int call_again_soon
= 0;
593 char incmsg
[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo
))];
595 mutex_lock(&con
->sock_mutex
);
597 if (con
->sock
== NULL
) {
602 if (con
->rx_page
== NULL
) {
604 * This doesn't need to be atomic, but I think it should
605 * improve performance if it is.
607 con
->rx_page
= alloc_page(GFP_ATOMIC
);
608 if (con
->rx_page
== NULL
)
610 cbuf_init(&con
->cb
, PAGE_CACHE_SIZE
);
613 /* Only SCTP needs these really */
614 memset(&incmsg
, 0, sizeof(incmsg
));
615 msg
.msg_control
= incmsg
;
616 msg
.msg_controllen
= sizeof(incmsg
);
619 * iov[0] is the bit of the circular buffer between the current end
620 * point (cb.base + cb.len) and the end of the buffer.
622 iov
[0].iov_len
= con
->cb
.base
- cbuf_data(&con
->cb
);
623 iov
[0].iov_base
= page_address(con
->rx_page
) + cbuf_data(&con
->cb
);
628 * iov[1] is the bit of the circular buffer between the start of the
629 * buffer and the start of the currently used section (cb.base)
631 if (cbuf_data(&con
->cb
) >= con
->cb
.base
) {
632 iov
[0].iov_len
= PAGE_CACHE_SIZE
- cbuf_data(&con
->cb
);
633 iov
[1].iov_len
= con
->cb
.base
;
634 iov
[1].iov_base
= page_address(con
->rx_page
);
637 len
= iov
[0].iov_len
+ iov
[1].iov_len
;
639 r
= ret
= kernel_recvmsg(con
->sock
, &msg
, iov
, nvec
, len
,
640 MSG_DONTWAIT
| MSG_NOSIGNAL
);
644 /* Process SCTP notifications */
645 if (msg
.msg_flags
& MSG_NOTIFICATION
) {
646 msg
.msg_control
= incmsg
;
647 msg
.msg_controllen
= sizeof(incmsg
);
649 process_sctp_notification(con
, &msg
,
650 page_address(con
->rx_page
) + con
->cb
.base
);
651 mutex_unlock(&con
->sock_mutex
);
654 BUG_ON(con
->nodeid
== 0);
658 cbuf_add(&con
->cb
, ret
);
659 ret
= dlm_process_incoming_buffer(con
->nodeid
,
660 page_address(con
->rx_page
),
661 con
->cb
.base
, con
->cb
.len
,
663 if (ret
== -EBADMSG
) {
664 log_print("lowcomms: addr=%p, base=%u, len=%u, "
665 "iov_len=%u, iov_base[0]=%p, read=%d",
666 page_address(con
->rx_page
), con
->cb
.base
, con
->cb
.len
,
667 len
, iov
[0].iov_base
, r
);
671 cbuf_eat(&con
->cb
, ret
);
673 if (cbuf_empty(&con
->cb
) && !call_again_soon
) {
674 __free_page(con
->rx_page
);
680 mutex_unlock(&con
->sock_mutex
);
684 if (!test_and_set_bit(CF_READ_PENDING
, &con
->flags
))
685 queue_work(recv_workqueue
, &con
->rwork
);
686 mutex_unlock(&con
->sock_mutex
);
690 mutex_unlock(&con
->sock_mutex
);
691 if (ret
!= -EAGAIN
) {
692 close_connection(con
, false);
693 /* Reconnect when there is something to send */
695 /* Don't return success if we really got EOF */
702 /* Listening socket is busy, accept a connection */
703 static int tcp_accept_from_sock(struct connection
*con
)
706 struct sockaddr_storage peeraddr
;
707 struct socket
*newsock
;
710 struct connection
*newcon
;
711 struct connection
*addcon
;
713 memset(&peeraddr
, 0, sizeof(peeraddr
));
714 result
= sock_create_kern(dlm_local_addr
[0]->ss_family
, SOCK_STREAM
,
715 IPPROTO_TCP
, &newsock
);
719 mutex_lock_nested(&con
->sock_mutex
, 0);
722 if (con
->sock
== NULL
)
725 newsock
->type
= con
->sock
->type
;
726 newsock
->ops
= con
->sock
->ops
;
728 result
= con
->sock
->ops
->accept(con
->sock
, newsock
, O_NONBLOCK
);
732 /* Get the connected socket's peer */
733 memset(&peeraddr
, 0, sizeof(peeraddr
));
734 if (newsock
->ops
->getname(newsock
, (struct sockaddr
*)&peeraddr
,
736 result
= -ECONNABORTED
;
740 /* Get the new node's NODEID */
741 make_sockaddr(&peeraddr
, 0, &len
);
742 if (dlm_addr_to_nodeid(&peeraddr
, &nodeid
)) {
743 unsigned char *b
=(unsigned char *)&peeraddr
;
744 log_print("connect from non cluster node");
745 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE
,
746 b
, sizeof(struct sockaddr_storage
));
747 sock_release(newsock
);
748 mutex_unlock(&con
->sock_mutex
);
752 log_print("got connection from %d", nodeid
);
754 /* Check to see if we already have a connection to this node. This
755 * could happen if the two nodes initiate a connection at roughly
756 * the same time and the connections cross on the wire.
757 * In this case we store the incoming one in "othercon"
759 newcon
= nodeid2con(nodeid
, GFP_NOFS
);
764 mutex_lock_nested(&newcon
->sock_mutex
, 1);
766 struct connection
*othercon
= newcon
->othercon
;
769 othercon
= kmem_cache_zalloc(con_cache
, GFP_NOFS
);
771 log_print("failed to allocate incoming socket");
772 mutex_unlock(&newcon
->sock_mutex
);
776 othercon
->nodeid
= nodeid
;
777 othercon
->rx_action
= receive_from_sock
;
778 mutex_init(&othercon
->sock_mutex
);
779 INIT_WORK(&othercon
->swork
, process_send_sockets
);
780 INIT_WORK(&othercon
->rwork
, process_recv_sockets
);
781 set_bit(CF_IS_OTHERCON
, &othercon
->flags
);
783 if (!othercon
->sock
) {
784 newcon
->othercon
= othercon
;
785 othercon
->sock
= newsock
;
786 newsock
->sk
->sk_user_data
= othercon
;
787 add_sock(newsock
, othercon
);
791 printk("Extra connection from node %d attempted\n", nodeid
);
793 mutex_unlock(&newcon
->sock_mutex
);
798 newsock
->sk
->sk_user_data
= newcon
;
799 newcon
->rx_action
= receive_from_sock
;
800 add_sock(newsock
, newcon
);
804 mutex_unlock(&newcon
->sock_mutex
);
807 * Add it to the active queue in case we got data
808 * between processing the accept adding the socket
809 * to the read_sockets list
811 if (!test_and_set_bit(CF_READ_PENDING
, &addcon
->flags
))
812 queue_work(recv_workqueue
, &addcon
->rwork
);
813 mutex_unlock(&con
->sock_mutex
);
818 mutex_unlock(&con
->sock_mutex
);
819 sock_release(newsock
);
821 if (result
!= -EAGAIN
)
822 log_print("error accepting connection from node: %d", result
);
826 static void free_entry(struct writequeue_entry
*e
)
828 __free_page(e
->page
);
832 /* Initiate an SCTP association.
833 This is a special case of send_to_sock() in that we don't yet have a
834 peeled-off socket for this association, so we use the listening socket
835 and add the primary IP address of the remote node.
837 static void sctp_init_assoc(struct connection
*con
)
839 struct sockaddr_storage rem_addr
;
840 char outcmsg
[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo
))];
841 struct msghdr outmessage
;
842 struct cmsghdr
*cmsg
;
843 struct sctp_sndrcvinfo
*sinfo
;
844 struct connection
*base_con
;
845 struct writequeue_entry
*e
;
851 if (test_and_set_bit(CF_INIT_PENDING
, &con
->flags
))
854 if (con
->retries
++ > MAX_CONNECT_RETRIES
)
857 if (nodeid_to_addr(con
->nodeid
, (struct sockaddr
*)&rem_addr
)) {
858 log_print("no address for nodeid %d", con
->nodeid
);
861 base_con
= nodeid2con(0, 0);
862 BUG_ON(base_con
== NULL
);
864 make_sockaddr(&rem_addr
, dlm_config
.ci_tcp_port
, &addrlen
);
866 outmessage
.msg_name
= &rem_addr
;
867 outmessage
.msg_namelen
= addrlen
;
868 outmessage
.msg_control
= outcmsg
;
869 outmessage
.msg_controllen
= sizeof(outcmsg
);
870 outmessage
.msg_flags
= MSG_EOR
;
872 spin_lock(&con
->writequeue_lock
);
874 if (list_empty(&con
->writequeue
)) {
875 spin_unlock(&con
->writequeue_lock
);
876 log_print("writequeue empty for nodeid %d", con
->nodeid
);
880 e
= list_first_entry(&con
->writequeue
, struct writequeue_entry
, list
);
883 spin_unlock(&con
->writequeue_lock
);
885 /* Send the first block off the write queue */
886 iov
[0].iov_base
= page_address(e
->page
)+offset
;
887 iov
[0].iov_len
= len
;
889 cmsg
= CMSG_FIRSTHDR(&outmessage
);
890 cmsg
->cmsg_level
= IPPROTO_SCTP
;
891 cmsg
->cmsg_type
= SCTP_SNDRCV
;
892 cmsg
->cmsg_len
= CMSG_LEN(sizeof(struct sctp_sndrcvinfo
));
893 sinfo
= CMSG_DATA(cmsg
);
894 memset(sinfo
, 0x00, sizeof(struct sctp_sndrcvinfo
));
895 sinfo
->sinfo_ppid
= cpu_to_le32(dlm_our_nodeid());
896 outmessage
.msg_controllen
= cmsg
->cmsg_len
;
898 ret
= kernel_sendmsg(base_con
->sock
, &outmessage
, iov
, 1, len
);
900 log_print("Send first packet to node %d failed: %d",
903 /* Try again later */
904 clear_bit(CF_CONNECT_PENDING
, &con
->flags
);
905 clear_bit(CF_INIT_PENDING
, &con
->flags
);
908 spin_lock(&con
->writequeue_lock
);
912 if (e
->len
== 0 && e
->users
== 0) {
916 spin_unlock(&con
->writequeue_lock
);
920 /* Connect a new socket to its peer */
921 static void tcp_connect_to_sock(struct connection
*con
)
923 int result
= -EHOSTUNREACH
;
924 struct sockaddr_storage saddr
, src_addr
;
926 struct socket
*sock
= NULL
;
929 if (con
->nodeid
== 0) {
930 log_print("attempt to connect sock 0 foiled");
934 mutex_lock(&con
->sock_mutex
);
935 if (con
->retries
++ > MAX_CONNECT_RETRIES
)
938 /* Some odd races can cause double-connects, ignore them */
944 /* Create a socket to communicate with */
945 result
= sock_create_kern(dlm_local_addr
[0]->ss_family
, SOCK_STREAM
,
950 memset(&saddr
, 0, sizeof(saddr
));
951 if (dlm_nodeid_to_addr(con
->nodeid
, &saddr
))
954 sock
->sk
->sk_user_data
= con
;
955 con
->rx_action
= receive_from_sock
;
956 con
->connect_action
= tcp_connect_to_sock
;
959 /* Bind to our cluster-known address connecting to avoid
961 memcpy(&src_addr
, dlm_local_addr
[0], sizeof(src_addr
));
962 make_sockaddr(&src_addr
, 0, &addr_len
);
963 result
= sock
->ops
->bind(sock
, (struct sockaddr
*) &src_addr
,
966 log_print("could not bind for connect: %d", result
);
967 /* This *may* not indicate a critical error */
970 make_sockaddr(&saddr
, dlm_config
.ci_tcp_port
, &addr_len
);
972 log_print("connecting to %d", con
->nodeid
);
974 /* Turn off Nagle's algorithm */
975 kernel_setsockopt(sock
, SOL_TCP
, TCP_NODELAY
, (char *)&one
,
979 sock
->ops
->connect(sock
, (struct sockaddr
*)&saddr
, addr_len
,
981 if (result
== -EINPROGRESS
)
988 sock_release(con
->sock
);
994 * Some errors are fatal and this list might need adjusting. For other
995 * errors we try again until the max number of retries is reached.
997 if (result
!= -EHOSTUNREACH
&& result
!= -ENETUNREACH
&&
998 result
!= -ENETDOWN
&& result
!= -EINVAL
999 && result
!= -EPROTONOSUPPORT
) {
1000 lowcomms_connect_sock(con
);
1004 mutex_unlock(&con
->sock_mutex
);
1008 static struct socket
*tcp_create_listen_sock(struct connection
*con
,
1009 struct sockaddr_storage
*saddr
)
1011 struct socket
*sock
= NULL
;
1016 if (dlm_local_addr
[0]->ss_family
== AF_INET
)
1017 addr_len
= sizeof(struct sockaddr_in
);
1019 addr_len
= sizeof(struct sockaddr_in6
);
1021 /* Create a socket to communicate with */
1022 result
= sock_create_kern(dlm_local_addr
[0]->ss_family
, SOCK_STREAM
,
1023 IPPROTO_TCP
, &sock
);
1025 log_print("Can't create listening comms socket");
1029 /* Turn off Nagle's algorithm */
1030 kernel_setsockopt(sock
, SOL_TCP
, TCP_NODELAY
, (char *)&one
,
1033 result
= kernel_setsockopt(sock
, SOL_SOCKET
, SO_REUSEADDR
,
1034 (char *)&one
, sizeof(one
));
1037 log_print("Failed to set SO_REUSEADDR on socket: %d", result
);
1039 sock
->sk
->sk_user_data
= con
;
1040 con
->rx_action
= tcp_accept_from_sock
;
1041 con
->connect_action
= tcp_connect_to_sock
;
1044 /* Bind to our port */
1045 make_sockaddr(saddr
, dlm_config
.ci_tcp_port
, &addr_len
);
1046 result
= sock
->ops
->bind(sock
, (struct sockaddr
*) saddr
, addr_len
);
1048 log_print("Can't bind to port %d", dlm_config
.ci_tcp_port
);
1054 result
= kernel_setsockopt(sock
, SOL_SOCKET
, SO_KEEPALIVE
,
1055 (char *)&one
, sizeof(one
));
1057 log_print("Set keepalive failed: %d", result
);
1060 result
= sock
->ops
->listen(sock
, 5);
1062 log_print("Can't listen on port %d", dlm_config
.ci_tcp_port
);
1072 /* Get local addresses */
1073 static void init_local(void)
1075 struct sockaddr_storage sas
, *addr
;
1078 dlm_local_count
= 0;
1079 for (i
= 0; i
< DLM_MAX_ADDR_COUNT
; i
++) {
1080 if (dlm_our_addr(&sas
, i
))
1083 addr
= kmalloc(sizeof(*addr
), GFP_NOFS
);
1086 memcpy(addr
, &sas
, sizeof(*addr
));
1087 dlm_local_addr
[dlm_local_count
++] = addr
;
1091 /* Bind to an IP address. SCTP allows multiple address so it can do
1093 static int add_sctp_bind_addr(struct connection
*sctp_con
,
1094 struct sockaddr_storage
*addr
,
1095 int addr_len
, int num
)
1100 result
= kernel_bind(sctp_con
->sock
,
1101 (struct sockaddr
*) addr
,
1104 result
= kernel_setsockopt(sctp_con
->sock
, SOL_SCTP
,
1105 SCTP_SOCKOPT_BINDX_ADD
,
1106 (char *)addr
, addr_len
);
1109 log_print("Can't bind to port %d addr number %d",
1110 dlm_config
.ci_tcp_port
, num
);
1115 /* Initialise SCTP socket and bind to all interfaces */
1116 static int sctp_listen_for_all(void)
1118 struct socket
*sock
= NULL
;
1119 struct sockaddr_storage localaddr
;
1120 struct sctp_event_subscribe subscribe
;
1121 int result
= -EINVAL
, num
= 1, i
, addr_len
;
1122 struct connection
*con
= nodeid2con(0, GFP_NOFS
);
1123 int bufsize
= NEEDED_RMEM
;
1128 log_print("Using SCTP for communications");
1130 result
= sock_create_kern(dlm_local_addr
[0]->ss_family
, SOCK_SEQPACKET
,
1131 IPPROTO_SCTP
, &sock
);
1133 log_print("Can't create comms socket, check SCTP is loaded");
1137 /* Listen for events */
1138 memset(&subscribe
, 0, sizeof(subscribe
));
1139 subscribe
.sctp_data_io_event
= 1;
1140 subscribe
.sctp_association_event
= 1;
1141 subscribe
.sctp_send_failure_event
= 1;
1142 subscribe
.sctp_shutdown_event
= 1;
1143 subscribe
.sctp_partial_delivery_event
= 1;
1145 result
= kernel_setsockopt(sock
, SOL_SOCKET
, SO_RCVBUFFORCE
,
1146 (char *)&bufsize
, sizeof(bufsize
));
1148 log_print("Error increasing buffer space on socket %d", result
);
1150 result
= kernel_setsockopt(sock
, SOL_SCTP
, SCTP_EVENTS
,
1151 (char *)&subscribe
, sizeof(subscribe
));
1153 log_print("Failed to set SCTP_EVENTS on socket: result=%d",
1155 goto create_delsock
;
1158 /* Init con struct */
1159 sock
->sk
->sk_user_data
= con
;
1161 con
->sock
->sk
->sk_data_ready
= lowcomms_data_ready
;
1162 con
->rx_action
= receive_from_sock
;
1163 con
->connect_action
= sctp_init_assoc
;
1165 /* Bind to all interfaces. */
1166 for (i
= 0; i
< dlm_local_count
; i
++) {
1167 memcpy(&localaddr
, dlm_local_addr
[i
], sizeof(localaddr
));
1168 make_sockaddr(&localaddr
, dlm_config
.ci_tcp_port
, &addr_len
);
1170 result
= add_sctp_bind_addr(con
, &localaddr
, addr_len
, num
);
1172 goto create_delsock
;
1176 result
= sock
->ops
->listen(sock
, 5);
1178 log_print("Can't set socket listening");
1179 goto create_delsock
;
1191 static int tcp_listen_for_all(void)
1193 struct socket
*sock
= NULL
;
1194 struct connection
*con
= nodeid2con(0, GFP_NOFS
);
1195 int result
= -EINVAL
;
1200 /* We don't support multi-homed hosts */
1201 if (dlm_local_addr
[1] != NULL
) {
1202 log_print("TCP protocol can't handle multi-homed hosts, "
1207 log_print("Using TCP for communications");
1209 sock
= tcp_create_listen_sock(con
, dlm_local_addr
[0]);
1211 add_sock(sock
, con
);
1215 result
= -EADDRINUSE
;
1223 static struct writequeue_entry
*new_writequeue_entry(struct connection
*con
,
1226 struct writequeue_entry
*entry
;
1228 entry
= kmalloc(sizeof(struct writequeue_entry
), allocation
);
1232 entry
->page
= alloc_page(allocation
);
1247 void *dlm_lowcomms_get_buffer(int nodeid
, int len
, gfp_t allocation
, char **ppc
)
1249 struct connection
*con
;
1250 struct writequeue_entry
*e
;
1254 con
= nodeid2con(nodeid
, allocation
);
1258 spin_lock(&con
->writequeue_lock
);
1259 e
= list_entry(con
->writequeue
.prev
, struct writequeue_entry
, list
);
1260 if ((&e
->list
== &con
->writequeue
) ||
1261 (PAGE_CACHE_SIZE
- e
->end
< len
)) {
1268 spin_unlock(&con
->writequeue_lock
);
1272 *ppc
= page_address(e
->page
) + offset
;
1276 e
= new_writequeue_entry(con
, allocation
);
1278 spin_lock(&con
->writequeue_lock
);
1282 list_add_tail(&e
->list
, &con
->writequeue
);
1283 spin_unlock(&con
->writequeue_lock
);
1289 void dlm_lowcomms_commit_buffer(void *mh
)
1291 struct writequeue_entry
*e
= (struct writequeue_entry
*)mh
;
1292 struct connection
*con
= e
->con
;
1295 spin_lock(&con
->writequeue_lock
);
1299 e
->len
= e
->end
- e
->offset
;
1300 spin_unlock(&con
->writequeue_lock
);
1302 if (!test_and_set_bit(CF_WRITE_PENDING
, &con
->flags
)) {
1303 queue_work(send_workqueue
, &con
->swork
);
1308 spin_unlock(&con
->writequeue_lock
);
1312 /* Send a message */
1313 static void send_to_sock(struct connection
*con
)
1316 const int msg_flags
= MSG_DONTWAIT
| MSG_NOSIGNAL
;
1317 struct writequeue_entry
*e
;
1321 mutex_lock(&con
->sock_mutex
);
1322 if (con
->sock
== NULL
)
1325 spin_lock(&con
->writequeue_lock
);
1327 e
= list_entry(con
->writequeue
.next
, struct writequeue_entry
,
1329 if ((struct list_head
*) e
== &con
->writequeue
)
1334 BUG_ON(len
== 0 && e
->users
== 0);
1335 spin_unlock(&con
->writequeue_lock
);
1339 ret
= kernel_sendpage(con
->sock
, e
->page
, offset
, len
,
1341 if (ret
== -EAGAIN
|| ret
== 0) {
1342 if (ret
== -EAGAIN
&&
1343 test_bit(SOCK_ASYNC_NOSPACE
, &con
->sock
->flags
) &&
1344 !test_and_set_bit(CF_APP_LIMITED
, &con
->flags
)) {
1345 /* Notify TCP that we're limited by the
1346 * application window size.
1348 set_bit(SOCK_NOSPACE
, &con
->sock
->flags
);
1349 con
->sock
->sk
->sk_write_pending
++;
1358 /* Don't starve people filling buffers */
1359 if (++count
>= MAX_SEND_MSG_COUNT
) {
1364 spin_lock(&con
->writequeue_lock
);
1368 if (e
->len
== 0 && e
->users
== 0) {
1374 spin_unlock(&con
->writequeue_lock
);
1376 mutex_unlock(&con
->sock_mutex
);
1380 mutex_unlock(&con
->sock_mutex
);
1381 close_connection(con
, false);
1382 lowcomms_connect_sock(con
);
1386 mutex_unlock(&con
->sock_mutex
);
1387 if (!test_bit(CF_INIT_PENDING
, &con
->flags
))
1388 lowcomms_connect_sock(con
);
1392 static void clean_one_writequeue(struct connection
*con
)
1394 struct writequeue_entry
*e
, *safe
;
1396 spin_lock(&con
->writequeue_lock
);
1397 list_for_each_entry_safe(e
, safe
, &con
->writequeue
, list
) {
1401 spin_unlock(&con
->writequeue_lock
);
1404 /* Called from recovery when it knows that a node has
1406 int dlm_lowcomms_close(int nodeid
)
1408 struct connection
*con
;
1410 log_print("closing connection to node %d", nodeid
);
1411 con
= nodeid2con(nodeid
, 0);
1413 clear_bit(CF_CONNECT_PENDING
, &con
->flags
);
1414 clear_bit(CF_WRITE_PENDING
, &con
->flags
);
1415 set_bit(CF_CLOSE
, &con
->flags
);
1416 if (cancel_work_sync(&con
->swork
))
1417 log_print("canceled swork for node %d", nodeid
);
1418 if (cancel_work_sync(&con
->rwork
))
1419 log_print("canceled rwork for node %d", nodeid
);
1420 clean_one_writequeue(con
);
1421 close_connection(con
, true);
1426 /* Receive workqueue function */
1427 static void process_recv_sockets(struct work_struct
*work
)
1429 struct connection
*con
= container_of(work
, struct connection
, rwork
);
1432 clear_bit(CF_READ_PENDING
, &con
->flags
);
1434 err
= con
->rx_action(con
);
1438 /* Send workqueue function */
1439 static void process_send_sockets(struct work_struct
*work
)
1441 struct connection
*con
= container_of(work
, struct connection
, swork
);
1443 if (test_and_clear_bit(CF_CONNECT_PENDING
, &con
->flags
)) {
1444 con
->connect_action(con
);
1445 set_bit(CF_WRITE_PENDING
, &con
->flags
);
1447 if (test_and_clear_bit(CF_WRITE_PENDING
, &con
->flags
))
1452 /* Discard all entries on the write queues */
1453 static void clean_writequeues(void)
1455 foreach_conn(clean_one_writequeue
);
1458 static void work_stop(void)
1460 destroy_workqueue(recv_workqueue
);
1461 destroy_workqueue(send_workqueue
);
1464 static int work_start(void)
1466 recv_workqueue
= alloc_workqueue("dlm_recv",
1467 WQ_UNBOUND
| WQ_MEM_RECLAIM
, 1);
1468 if (!recv_workqueue
) {
1469 log_print("can't start dlm_recv");
1473 send_workqueue
= alloc_workqueue("dlm_send",
1474 WQ_UNBOUND
| WQ_MEM_RECLAIM
, 1);
1475 if (!send_workqueue
) {
1476 log_print("can't start dlm_send");
1477 destroy_workqueue(recv_workqueue
);
1484 static void stop_conn(struct connection
*con
)
1487 if (con
->sock
&& con
->sock
->sk
)
1488 con
->sock
->sk
->sk_user_data
= NULL
;
1491 static void free_conn(struct connection
*con
)
1493 close_connection(con
, true);
1495 kmem_cache_free(con_cache
, con
->othercon
);
1496 hlist_del(&con
->list
);
1497 kmem_cache_free(con_cache
, con
);
1500 void dlm_lowcomms_stop(void)
1502 /* Set all the flags to prevent any
1505 mutex_lock(&connections_lock
);
1506 foreach_conn(stop_conn
);
1507 mutex_unlock(&connections_lock
);
1511 mutex_lock(&connections_lock
);
1512 clean_writequeues();
1514 foreach_conn(free_conn
);
1516 mutex_unlock(&connections_lock
);
1517 kmem_cache_destroy(con_cache
);
1520 int dlm_lowcomms_start(void)
1522 int error
= -EINVAL
;
1523 struct connection
*con
;
1526 for (i
= 0; i
< CONN_HASH_SIZE
; i
++)
1527 INIT_HLIST_HEAD(&connection_hash
[i
]);
1530 if (!dlm_local_count
) {
1532 log_print("no local IP address has been set");
1537 con_cache
= kmem_cache_create("dlm_conn", sizeof(struct connection
),
1538 __alignof__(struct connection
), 0,
1543 /* Start listening */
1544 if (dlm_config
.ci_protocol
== 0)
1545 error
= tcp_listen_for_all();
1547 error
= sctp_listen_for_all();
1551 error
= work_start();
1558 con
= nodeid2con(0,0);
1560 close_connection(con
, false);
1561 kmem_cache_free(con_cache
, con
);
1563 kmem_cache_destroy(con_cache
);