hammer2 - spanning tree and messaging work
[dragonfly.git] / sbin / hammer2 / msg_lnk.c
CommitLineData
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1/*
2 * Copyright (c) 2012 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@dragonflybsd.org>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34/*
35 * LNK_SPAN PROTOCOL SUPPORT FUNCTIONS
36 *
37 * This code supports the LNK_SPAN protocol. Essentially all PFS's
38 * clients and services rendezvous with the userland hammer2 service and
39 * open LNK_SPAN transactions using a message header linkid of 0,
40 * registering any PFS's they have connectivity to with us.
41 *
42 * --
43 *
44 * Each registration maintains its own open LNK_SPAN message transaction.
45 * The SPANs are collected, aggregated, and retransmitted over available
46 * connections through the maintainance of additional LNK_SPAN message
47 * transactions on each link.
48 *
49 * The msgid for each active LNK_SPAN transaction we receive allows us to
50 * send a message to the target PFS (which might be one of many belonging
51 * to the same cluster), by specifying that msgid as the linkid in any
52 * message we send to the target PFS.
53 *
54 * Similarly the msgid we allocate for any LNK_SPAN transaction we transmit
55 * (and remember we will maintain multiple open LNK_SPAN transactions on
56 * each connection representing the topology span, so every node sees every
57 * other node as a separate open transaction). So, similarly the msgid for
58 * these active transactions which we initiated can be used by the other
59 * end to route messages through us to another node, ultimately winding up
60 * at the identified hammer2 PFS. We have to adjust the spanid in the message
61 * header at each hop to be representative of the outgoing LNK_SPAN we
62 * are forwarding the message through.
63 *
64 * --
65 *
66 * If we were to retransmit every LNK_SPAN transaction we receive it would
67 * create a huge mess, so we have to aggregate all received LNK_SPAN
68 * transactions, sort them by the fsid (the cluster) and sub-sort them by
69 * the pfs_fsid (individual nodes in the cluster), and only retransmit
7dc0f844 70 * (create outgoing transactions) for a subset of the nearest distance-hops
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71 * for each individual node.
72 *
73 * The higher level protocols can then issue transactions to the nodes making
74 * up a cluster to perform all actions required.
75 *
76 * --
77 *
78 * Since this is a large topology and a spanning tree protocol, links can
79 * go up and down all the time. Any time a link goes down its transaction
80 * is closed. The transaction has to be closed on both ends before we can
81 * delete (and potentially reuse) the related spanid. The LNK_SPAN being
82 * closed may have been propagated out to other connections and those related
83 * LNK_SPANs are also closed. Ultimately all routes via the lost LNK_SPAN
84 * go away, ultimately reaching all sources and all targets.
85 *
86 * Any messages in-transit using a route that goes away will be thrown away.
87 * Open transactions are only tracked at the two end-points. When a link
88 * failure propagates to an end-point the related open transactions lose
89 * their spanid and are automatically aborted.
90 *
91 * It is important to note that internal route nodes cannot just associate
92 * a lost LNK_SPAN transaction with another route to the same destination.
93 * Message transactions MUST be serialized and MUST be ordered. All messages
94 * for a transaction must run over the same route. So if the route used by
95 * an active transaction is lost, the related messages will be fully aborted
96 * and the higher protocol levels will retry as appropriate.
97 *
98 * It is also important to note that several paths to the same PFS can be
99 * propagated along the same link, which allows concurrency and even
100 * redundancy over several network interfaces or via different routes through
101 * the topology. Any given transaction will use only a single route but busy
102 * servers will often have hundreds of transactions active simultaniously,
103 * so having multiple active paths through the network topology for A<->B
104 * will improve performance.
105 *
106 * --
107 *
108 * Most protocols consolidate operations rather than simply relaying them.
109 * This is particularly true of LEAF protocols (such as strict HAMMER2
110 * clients), of which there can be millions connecting into the cluster at
111 * various points. The SPAN protocol is not used for these LEAF elements.
112 *
113 * Instead the primary service they connect to implements a proxy for the
114 * client protocols so the core topology only has to propagate a couple of
115 * LNK_SPANs and not millions. LNK_SPANs are meant to be used only for
116 * core master nodes and satellite slaves and cache nodes.
117 */
118
119#include "hammer2.h"
120
121/*
122 * RED-BLACK TREE DEFINITIONS
123 *
7dc0f844 124 * We need to track:
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125 *
126 * (1) shared fsid's (a cluster).
127 * (2) unique fsid's (a node in a cluster) <--- LNK_SPAN transactions.
128 *
129 * We need to aggegate all active LNK_SPANs, aggregate, and create our own
130 * outgoing LNK_SPAN transactions on each of our connections representing
131 * the aggregated state.
132 *
133 * h2span_connect - list of iocom connections who wish to receive SPAN
134 * propagation from other connections. Might contain
135 * a filter string. Only iocom's with an open
136 * LNK_CONN transactions are applicable for SPAN
137 * propagation.
138 *
139 * h2span_relay - List of links relayed (via SPAN). Essentially
140 * each relay structure represents a LNK_SPAN
141 * transaction that we initiated, verses h2span_link
142 * which is a LNK_SPAN transaction that we received.
143 *
144 * --
145 *
146 * h2span_cluster - Organizes the shared fsid's. One structure for
147 * each cluster.
148 *
149 * h2span_node - Organizes the nodes in a cluster. One structure
150 * for each unique {cluster,node}, aka {fsid, pfs_fsid}.
151 *
152 * h2span_link - Organizes all incoming and outgoing LNK_SPAN message
153 * transactions related to a node.
154 *
155 * One h2span_link structure for each incoming LNK_SPAN
156 * transaction. Links selected for propagation back
157 * out are also where the outgoing LNK_SPAN messages
158 * are indexed into (so we can propagate changes).
159 *
160 * The h2span_link's use a red-black tree to sort the
7dc0f844 161 * distance hop metric for the incoming LNK_SPAN. We
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162 * then select the top N for outgoing. When the
163 * topology changes the top N may also change and cause
164 * new outgoing LNK_SPAN transactions to be opened
165 * and less desireable ones to be closed, causing
166 * transactional aborts within the message flow in
167 * the process.
168 *
169 * Also note - All outgoing LNK_SPAN message transactions are also
170 * entered into a red-black tree for use by the routing
171 * function. This is handled by msg.c in the state
172 * code, not here.
173 */
174
175struct h2span_link;
176struct h2span_relay;
177TAILQ_HEAD(h2span_connect_queue, h2span_connect);
178TAILQ_HEAD(h2span_relay_queue, h2span_relay);
179
180RB_HEAD(h2span_cluster_tree, h2span_cluster);
181RB_HEAD(h2span_node_tree, h2span_node);
182RB_HEAD(h2span_link_tree, h2span_link);
183RB_HEAD(h2span_relay_tree, h2span_relay);
184
185/*
186 * Received LNK_CONN transaction enables SPAN protocol over connection.
187 * (may contain filter).
188 */
189struct h2span_connect {
190 TAILQ_ENTRY(h2span_connect) entry;
191 struct h2span_relay_tree tree;
192 hammer2_state_t *state;
193};
194
195/*
196 * All received LNK_SPANs are organized by cluster (pfs_clid),
197 * node (pfs_fsid), and link (received LNK_SPAN transaction).
198 */
199struct h2span_cluster {
200 RB_ENTRY(h2span_cluster) rbnode;
201 struct h2span_node_tree tree;
202 uuid_t pfs_clid; /* shared fsid */
203};
204
7dc0f844 205struct h2span_node {
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206 RB_ENTRY(h2span_node) rbnode;
207 struct h2span_link_tree tree;
208 struct h2span_cluster *cls;
209 uuid_t pfs_fsid; /* unique fsid */
210};
211
212struct h2span_link {
213 RB_ENTRY(h2span_link) rbnode;
214 hammer2_state_t *state; /* state<->link */
215 struct h2span_node *node; /* related node */
7dc0f844 216 int32_t dist;
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217 struct h2span_relay_queue relayq; /* relay out */
218};
219
220/*
221 * Any LNK_SPAN transactions we receive which are relayed out other
222 * connections utilize this structure to track the LNK_SPAN transaction
223 * we initiate on the other connections, if selected for relay.
224 *
225 * In many respects this is the core of the protocol... actually figuring
226 * out what LNK_SPANs to relay. The spanid used for relaying is the
227 * address of the 'state' structure, which is why h2span_relay has to
228 * be entered into a RB-TREE based at h2span_connect (so we can look
229 * up the spanid to validate it).
230 */
231struct h2span_relay {
232 RB_ENTRY(h2span_relay) rbnode; /* from h2span_connect */
233 TAILQ_ENTRY(h2span_relay) entry; /* from link */
234 struct h2span_connect *conn;
235 hammer2_state_t *state; /* transmitted LNK_SPAN */
236 struct h2span_link *link; /* received LNK_SPAN */
237};
238
239
240typedef struct h2span_connect h2span_connect_t;
241typedef struct h2span_cluster h2span_cluster_t;
242typedef struct h2span_node h2span_node_t;
243typedef struct h2span_link h2span_link_t;
244typedef struct h2span_relay h2span_relay_t;
245
246static
247int
248h2span_cluster_cmp(h2span_cluster_t *cls1, h2span_cluster_t *cls2)
249{
250 return(uuid_compare(&cls1->pfs_clid, &cls2->pfs_clid, NULL));
251}
252
253static
254int
255h2span_node_cmp(h2span_node_t *node1, h2span_node_t *node2)
256{
257 return(uuid_compare(&node1->pfs_fsid, &node2->pfs_fsid, NULL));
258}
259
260static
261int
262h2span_link_cmp(h2span_link_t *link1, h2span_link_t *link2)
263{
7dc0f844 264 if (link1->dist < link2->dist)
8c280d5d 265 return(-1);
7dc0f844 266 if (link1->dist > link2->dist)
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267 return(1);
268 if ((intptr_t)link1 < (intptr_t)link2)
269 return(-1);
270 if ((intptr_t)link1 > (intptr_t)link2)
271 return(1);
272 return(0);
273}
274
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275/*
276 * Relay entries are sorted by node, subsorted by distance and link
277 * address (so we can match up the conn->tree relay topology with
278 * a node's link topology).
279 */
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280static
281int
282h2span_relay_cmp(h2span_relay_t *relay1, h2span_relay_t *relay2)
283{
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284 if ((intptr_t)relay1->link->node < (intptr_t)relay2->link->node)
285 return(-1);
286 if ((intptr_t)relay1->link->node > (intptr_t)relay2->link->node)
287 return(1);
288 if ((intptr_t)relay1->link->dist < (intptr_t)relay2->link->dist)
8c280d5d 289 return(-1);
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290 if ((intptr_t)relay1->link->dist > (intptr_t)relay2->link->dist)
291 return(1);
292 if ((intptr_t)relay1->link < (intptr_t)relay2->link)
293 return(-1);
294 if ((intptr_t)relay1->link > (intptr_t)relay2->link)
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295 return(1);
296 return(0);
297}
298
299RB_PROTOTYPE_STATIC(h2span_cluster_tree, h2span_cluster,
300 rbnode, h2span_cluster_cmp);
301RB_PROTOTYPE_STATIC(h2span_node_tree, h2span_node,
302 rbnode, h2span_node_cmp);
303RB_PROTOTYPE_STATIC(h2span_link_tree, h2span_link,
304 rbnode, h2span_link_cmp);
305RB_PROTOTYPE_STATIC(h2span_relay_tree, h2span_relay,
306 rbnode, h2span_relay_cmp);
307
308RB_GENERATE_STATIC(h2span_cluster_tree, h2span_cluster,
309 rbnode, h2span_cluster_cmp);
310RB_GENERATE_STATIC(h2span_node_tree, h2span_node,
311 rbnode, h2span_node_cmp);
312RB_GENERATE_STATIC(h2span_link_tree, h2span_link,
313 rbnode, h2span_link_cmp);
314RB_GENERATE_STATIC(h2span_relay_tree, h2span_relay,
315 rbnode, h2span_relay_cmp);
316
317/*
318 * Global mutex protects cluster_tree lookups.
319 */
320static pthread_mutex_t cluster_mtx;
321static struct h2span_cluster_tree cluster_tree = RB_INITIALIZER(cluster_tree);
322static struct h2span_connect_queue connq = TAILQ_HEAD_INITIALIZER(connq);
323
324static void hammer2_lnk_span(hammer2_state_t *state, hammer2_msg_t *msg);
325static void hammer2_lnk_conn(hammer2_state_t *state, hammer2_msg_t *msg);
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326static void hammer2_lnk_relay(hammer2_state_t *state, hammer2_msg_t *msg);
327static void hammer2_relay_scan(h2span_node_t *node);
328static void hammer2_relay_delete(h2span_relay_t *relay);
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329
330/*
331 * Receive a HAMMER2_MSG_PROTO_LNK message. This only called for
332 * one-way and opening-transactions since state->func will be assigned
333 * in all other cases.
334 */
335void
336hammer2_msg_lnk(hammer2_iocom_t *iocom, hammer2_msg_t *msg)
337{
338 switch(msg->any.head.cmd & HAMMER2_MSGF_BASECMDMASK) {
339 case HAMMER2_LNK_CONN:
340 hammer2_lnk_conn(msg->state, msg);
341 break;
342 case HAMMER2_LNK_SPAN:
343 hammer2_lnk_span(msg->state, msg);
344 break;
345 default:
346 fprintf(stderr,
347 "MSG_PROTO_LNK: Unknown msg %08x\n", msg->any.head.cmd);
348 hammer2_msg_reply(iocom, msg, HAMMER2_MSG_ERR_UNKNOWN);
349 /* state invalid after reply */
350 break;
351 }
352}
353
354void
355hammer2_lnk_conn(hammer2_state_t *state, hammer2_msg_t *msg)
356{
357 h2span_connect_t *conn;
358 h2span_relay_t *relay;
359 char *alloc = NULL;
360
361 pthread_mutex_lock(&cluster_mtx);
362
363 /*
364 * On transaction start we allocate a new h2span_connect and
365 * acknowledge the request, leaving the transaction open.
7dc0f844 366 * We then relay priority-selected SPANs.
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367 */
368 if (msg->any.head.cmd & HAMMER2_MSGF_CREATE) {
369 state->func = hammer2_lnk_conn;
370
371 fprintf(stderr, "LNK_CONN(%016jx): %s/%s\n",
372 (intmax_t)msg->any.head.msgid,
373 hammer2_uuid_to_str(&msg->any.lnk_conn.pfs_clid,
374 &alloc),
375 msg->any.lnk_conn.label);
376 free(alloc);
377
378 conn = hammer2_alloc(sizeof(*conn));
379
380 RB_INIT(&conn->tree);
381 conn->state = state;
382 state->any.conn = conn;
383 TAILQ_INSERT_TAIL(&connq, conn, entry);
384
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385 hammer2_msg_result(state->iocom, msg, 0);
386 }
387
388 /*
389 * On transaction terminate we clean out our h2span_connect
390 * and acknowledge the request, closing the transaction.
391 */
392 if (msg->any.head.cmd & HAMMER2_MSGF_DELETE) {
393 fprintf(stderr, "LNK_CONN: Terminated\n");
394 conn = state->any.conn;
395 assert(conn);
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396
397 /*
398 * Clean out all relays. This requires terminating each
399 * relay transaction.
400 */
8c280d5d 401 while ((relay = RB_ROOT(&conn->tree)) != NULL) {
7dc0f844 402 hammer2_relay_delete(relay);
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403 }
404
405 /*
406 * Clean out conn
407 */
408 conn->state = NULL;
409 msg->state->any.conn = NULL;
410 TAILQ_REMOVE(&connq, conn, entry);
411 hammer2_free(conn);
412
413 hammer2_msg_reply(state->iocom, msg, 0);
414 /* state invalid after reply */
415 }
416 pthread_mutex_unlock(&cluster_mtx);
417}
418
419void
420hammer2_lnk_span(hammer2_state_t *state, hammer2_msg_t *msg)
421{
422 h2span_cluster_t dummy_cls;
423 h2span_node_t dummy_node;
424 h2span_cluster_t *cls;
425 h2span_node_t *node;
426 h2span_link_t *slink;
427 h2span_relay_t *relay;
428 char *alloc = NULL;
429
430 pthread_mutex_lock(&cluster_mtx);
431
432 /*
433 * On transaction start we initialize the tracking infrastructure
434 */
435 if (msg->any.head.cmd & HAMMER2_MSGF_CREATE) {
436 state->func = hammer2_lnk_span;
437
438 fprintf(stderr, "LNK_SPAN: %s/%s\n",
439 hammer2_uuid_to_str(&msg->any.lnk_span.pfs_clid,
440 &alloc),
441 msg->any.lnk_span.label);
442 free(alloc);
443
444 /*
445 * Find the cluster
446 */
447 dummy_cls.pfs_clid = msg->any.lnk_span.pfs_clid;
448 cls = RB_FIND(h2span_cluster_tree, &cluster_tree, &dummy_cls);
449 if (cls == NULL) {
450 cls = hammer2_alloc(sizeof(*cls));
451 cls->pfs_clid = msg->any.lnk_span.pfs_clid;
452 RB_INIT(&cls->tree);
453 RB_INSERT(h2span_cluster_tree, &cluster_tree, cls);
454 }
455
456 /*
457 * Find the node
458 */
459 dummy_node.pfs_fsid = msg->any.lnk_span.pfs_fsid;
460 node = RB_FIND(h2span_node_tree, &cls->tree, &dummy_node);
461 if (node == NULL) {
462 node = hammer2_alloc(sizeof(*node));
463 node->pfs_fsid = msg->any.lnk_span.pfs_fsid;
464 node->cls = cls;
465 RB_INIT(&node->tree);
466 RB_INSERT(h2span_node_tree, &cls->tree, node);
467 }
468
469 /*
470 * Create the link
471 */
472 assert(state->any.link == NULL);
473 slink = hammer2_alloc(sizeof(*slink));
7dc0f844 474 TAILQ_INIT(&slink->relayq);
8c280d5d 475 slink->node = node;
7dc0f844 476 slink->dist = msg->any.lnk_span.dist;
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477 slink->state = state;
478 state->any.link = slink;
479 RB_INSERT(h2span_link_tree, &node->tree, slink);
480
7dc0f844 481 hammer2_relay_scan(node);
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482 }
483
484 /*
485 * On transaction terminate we remove the tracking infrastructure.
486 */
487 if (msg->any.head.cmd & HAMMER2_MSGF_DELETE) {
488 slink = state->any.link;
489 assert(slink != NULL);
490 node = slink->node;
491 cls = node->cls;
492
493 /*
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494 * Clean out all relays. This requires terminating each
495 * relay transaction.
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496 */
497 while ((relay = TAILQ_FIRST(&slink->relayq)) != NULL) {
7dc0f844 498 hammer2_relay_delete(relay);
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499 }
500
501 /*
502 * Clean out the topology
503 */
504 RB_REMOVE(h2span_link_tree, &node->tree, slink);
505 if (RB_EMPTY(&node->tree)) {
506 RB_REMOVE(h2span_node_tree, &cls->tree, node);
507 if (RB_EMPTY(&cls->tree)) {
508 RB_REMOVE(h2span_cluster_tree,
509 &cluster_tree, cls);
510 hammer2_free(cls);
511 }
512 node->cls = NULL;
513 hammer2_free(node);
7dc0f844 514 node = NULL;
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515 }
516 state->any.link = NULL;
517 slink->state = NULL;
518 slink->node = NULL;
519 hammer2_free(slink);
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520
521 /*
522 * We have to terminate the transaction
523 */
524 hammer2_state_reply(state, 0);
525 /* state invalid after reply */
526
527 /*
528 * If the node still exists issue any required updates. If
529 * it doesn't then all related relays have already been
530 * removed and there's nothing left to do.
531 */
532 if (node)
533 hammer2_relay_scan(node);
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534 }
535
536 pthread_mutex_unlock(&cluster_mtx);
537}
538
539/*
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540 * Messages received on relay SPANs. These are open transactions so it is
541 * in fact possible for the other end to close the transaction.
542 *
543 * XXX MPRACE on state structure
544 */
545static void
546hammer2_lnk_relay(hammer2_state_t *state, hammer2_msg_t *msg)
547{
548 h2span_relay_t *relay;
549
550 if (msg->any.head.cmd & HAMMER2_MSGF_DELETE) {
551 pthread_mutex_lock(&cluster_mtx);
552 if ((relay = state->any.relay) != NULL) {
553 hammer2_relay_delete(relay);
554 } else {
555 hammer2_state_reply(state, 0);
556 }
557 pthread_mutex_unlock(&cluster_mtx);
558 }
559}
560
561/*
562 * Update relay transactions for SPANs.
563 *
564 * Called with cluster_mtx held.
565 */
566static void hammer2_relay_scan_conn(h2span_node_t *node,
567 h2span_connect_t *conn);
568
569static void
570hammer2_relay_scan(h2span_node_t *node)
571{
572 h2span_cluster_t *cls;
573 h2span_connect_t *conn;
574
575 if (node) {
576 /*
577 * Iterate specific node
578 */
579 TAILQ_FOREACH(conn, &connq, entry)
580 hammer2_relay_scan_conn(node, conn);
581 } else {
582 /*
583 * Full iteration (not currently implemented)
584 *
585 * Iterate cluster ids
586 */
587 assert(0);
588 RB_FOREACH(cls, h2span_cluster_tree, &cluster_tree) {
589 /*
590 * Iterate node ids
591 */
592 RB_FOREACH(node, h2span_node_tree, &cls->tree) {
593 /*
594 * Synchronize the node's link (received SPANs)
595 * with each connection's relays.
596 */
597 TAILQ_FOREACH(conn, &connq, entry)
598 hammer2_relay_scan_conn(node, conn);
599 }
600 }
601 }
602}
603
604/*
605 * Update the relay'd SPANs for this (node, conn).
606 *
607 * Iterate links and adjust relays to match. We only propagate the top link
608 * for now (XXX we want to propagate the top two).
609 *
610 * The hammer2_relay_scan_cmp() function locates the first relay element
611 * for any given node. The relay elements will be sub-sorted by dist.
8c280d5d 612 */
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613struct relay_scan_info {
614 h2span_node_t *node;
615 h2span_relay_t *relay;
616};
617
618static int
619hammer2_relay_scan_cmp(h2span_relay_t *relay, void *arg)
620{
621 struct relay_scan_info *info = arg;
622
623 if ((intptr_t)relay->link->node < (intptr_t)info->node)
624 return(-1);
625 if ((intptr_t)relay->link->node > (intptr_t)info->node)
626 return(1);
627 return(0);
628}
629
630static int
631hammer2_relay_scan_callback(h2span_relay_t *relay, void *arg)
632{
633 struct relay_scan_info *info = arg;
634
635 info->relay = relay;
636 return(-1);
637}
638
8c280d5d 639static void
7dc0f844 640hammer2_relay_scan_conn(h2span_node_t *node, h2span_connect_t *conn)
8c280d5d 641{
7dc0f844
MD
642 struct relay_scan_info info;
643 h2span_relay_t *relay;
644 h2span_relay_t *next_relay;
645 h2span_link_t *slink;
646 int count = 2;
647
648 info.node = node;
649 info.relay = NULL;
650
651 /*
652 * Locate the first related relay for the connection. relay will
653 * be NULL if there were none.
654 */
655 RB_SCAN(h2span_relay_tree, &conn->tree,
656 hammer2_relay_scan_cmp, hammer2_relay_scan_callback, &info);
657 relay = info.relay;
658
659 fprintf(stderr, "relay scan for connection %p\n", conn);
660
661 /*
662 * Iterate the node's links (received SPANs) in distance order,
663 * lowest (best) dist first.
664 */
665 RB_FOREACH(slink, h2span_link_tree, &node->tree) {
666 /*
667 * PROPAGATE THE BEST RELAYS BY TRANSMITTING SPANs.
668 *
669 * Check for match against current best relay.
670 *
671 * A match failure means that the current best relay is not
672 * as good as the link, create a new relay for the link.
673 *
674 * (If some prior better link was removed it would have also
675 * removed the relay, so the relay can only match exactly or
676 * be worst).
677 */
678 info.relay = relay;
679 if (relay == NULL || relay->link != slink) {
680 hammer2_msg_t *msg;
681
682 assert(relay == NULL ||
683 slink->dist <= relay->link->dist);
684 relay = hammer2_alloc(sizeof(*relay));
685 relay->conn = conn;
686 relay->link = slink;
687
688 msg = hammer2_msg_alloc(conn->state->iocom, 0,
689 HAMMER2_LNK_SPAN |
690 HAMMER2_MSGF_CREATE);
691 msg->any.lnk_span = slink->state->msg->any.lnk_span;
692 ++msg->any.lnk_span.dist; /* XXX add weighting */
693
694 hammer2_msg_write(conn->state->iocom, msg,
695 hammer2_lnk_relay, relay,
696 &relay->state);
697 fprintf(stderr, "RELAY SPAN ON CLS=%p NODE=%p FD %d state %p\n",
698 node->cls, node,
699 conn->state->iocom->sock_fd, relay->state);
700
701 RB_INSERT(h2span_relay_tree, &conn->tree, relay);
702 TAILQ_INSERT_TAIL(&slink->relayq, relay, entry);
703 }
704
705 /*
706 * Iterate, figure out the next relay.
707 */
708 relay = RB_NEXT(h2span_relay_tree, &conn->tree, relay);
709 if (--count == 0) {
710 break;
711 continue;
712 }
713 }
714
715 /*
716 * Any remaining relay's belonging to this connection which match
717 * the node are in excess of the current aggregate spanning state
718 * and should be removed.
719 */
720 while (relay && relay->link->node == node) {
721 next_relay = RB_NEXT(h2span_relay_tree, &conn->tree, relay);
722 hammer2_relay_delete(relay);
723 relay = next_relay;
724 }
725}
726
727static
728void
729hammer2_relay_delete(h2span_relay_t *relay)
730{
731 fprintf(stderr, "RELAY DELETE ON CLS=%p NODE=%p FD %d STATE %p\n",
732 relay->link->node->cls, relay->link->node,
733 relay->conn->state->iocom->sock_fd, relay->state);
734 fprintf(stderr, "RELAY TX %08x RX %08x\n", relay->state->txcmd, relay->state->rxcmd);
735
736 RB_REMOVE(h2span_relay_tree, &relay->conn->tree, relay);
737 TAILQ_REMOVE(&relay->link->relayq, relay, entry);
738
739 if (relay->state) {
740 relay->state->any.relay = NULL;
741 hammer2_state_reply(relay->state, 0);
742 /* state invalid after reply */
743 relay->state = NULL;
744 }
745 relay->conn = NULL;
746 relay->link = NULL;
747 hammer2_free(relay);
8c280d5d 748}