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6714d8e8 KH |
1 | /* -*- mode: c; c-basic-offset: 8; -*- |
2 | * vim: noexpandtab sw=8 ts=8 sts=0: | |
3 | * | |
4 | * dlmmod.c | |
5 | * | |
6 | * standalone DLM module | |
7 | * | |
8 | * Copyright (C) 2004 Oracle. All rights reserved. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public | |
12 | * License as published by the Free Software Foundation; either | |
13 | * version 2 of the License, or (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public | |
21 | * License along with this program; if not, write to the | |
22 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
23 | * Boston, MA 021110-1307, USA. | |
24 | * | |
25 | */ | |
26 | ||
27 | ||
28 | #include <linux/module.h> | |
29 | #include <linux/fs.h> | |
30 | #include <linux/types.h> | |
31 | #include <linux/slab.h> | |
32 | #include <linux/highmem.h> | |
33 | #include <linux/utsname.h> | |
34 | #include <linux/init.h> | |
35 | #include <linux/sysctl.h> | |
36 | #include <linux/random.h> | |
37 | #include <linux/blkdev.h> | |
38 | #include <linux/socket.h> | |
39 | #include <linux/inet.h> | |
40 | #include <linux/spinlock.h> | |
41 | #include <linux/delay.h> | |
42 | ||
43 | ||
44 | #include "cluster/heartbeat.h" | |
45 | #include "cluster/nodemanager.h" | |
46 | #include "cluster/tcp.h" | |
47 | ||
48 | #include "dlmapi.h" | |
49 | #include "dlmcommon.h" | |
50 | #include "dlmdebug.h" | |
82353b59 | 51 | #include "dlmdomain.h" |
6714d8e8 KH |
52 | |
53 | #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER) | |
54 | #include "cluster/masklog.h" | |
55 | ||
56 | enum dlm_mle_type { | |
57 | DLM_MLE_BLOCK, | |
58 | DLM_MLE_MASTER, | |
59 | DLM_MLE_MIGRATION | |
60 | }; | |
61 | ||
62 | struct dlm_lock_name | |
63 | { | |
64 | u8 len; | |
65 | u8 name[DLM_LOCKID_NAME_MAX]; | |
66 | }; | |
67 | ||
68 | struct dlm_master_list_entry | |
69 | { | |
70 | struct list_head list; | |
71 | struct list_head hb_events; | |
72 | struct dlm_ctxt *dlm; | |
73 | spinlock_t spinlock; | |
74 | wait_queue_head_t wq; | |
75 | atomic_t woken; | |
76 | struct kref mle_refs; | |
77 | unsigned long maybe_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; | |
78 | unsigned long vote_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; | |
79 | unsigned long response_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; | |
80 | unsigned long node_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; | |
81 | u8 master; | |
82 | u8 new_master; | |
83 | enum dlm_mle_type type; | |
84 | struct o2hb_callback_func mle_hb_up; | |
85 | struct o2hb_callback_func mle_hb_down; | |
86 | union { | |
87 | struct dlm_lock_resource *res; | |
88 | struct dlm_lock_name name; | |
89 | } u; | |
90 | }; | |
91 | ||
92 | static void dlm_mle_node_down(struct dlm_ctxt *dlm, | |
93 | struct dlm_master_list_entry *mle, | |
94 | struct o2nm_node *node, | |
95 | int idx); | |
96 | static void dlm_mle_node_up(struct dlm_ctxt *dlm, | |
97 | struct dlm_master_list_entry *mle, | |
98 | struct o2nm_node *node, | |
99 | int idx); | |
100 | ||
101 | static void dlm_assert_master_worker(struct dlm_work_item *item, void *data); | |
102 | static int dlm_do_assert_master(struct dlm_ctxt *dlm, const char *lockname, | |
103 | unsigned int namelen, void *nodemap, | |
104 | u32 flags); | |
105 | ||
106 | static inline int dlm_mle_equal(struct dlm_ctxt *dlm, | |
107 | struct dlm_master_list_entry *mle, | |
108 | const char *name, | |
109 | unsigned int namelen) | |
110 | { | |
111 | struct dlm_lock_resource *res; | |
112 | ||
113 | if (dlm != mle->dlm) | |
114 | return 0; | |
115 | ||
116 | if (mle->type == DLM_MLE_BLOCK || | |
117 | mle->type == DLM_MLE_MIGRATION) { | |
118 | if (namelen != mle->u.name.len || | |
119 | memcmp(name, mle->u.name.name, namelen)!=0) | |
120 | return 0; | |
121 | } else { | |
122 | res = mle->u.res; | |
123 | if (namelen != res->lockname.len || | |
124 | memcmp(res->lockname.name, name, namelen) != 0) | |
125 | return 0; | |
126 | } | |
127 | return 1; | |
128 | } | |
129 | ||
130 | #if 0 | |
131 | /* Code here is included but defined out as it aids debugging */ | |
132 | ||
133 | void dlm_print_one_mle(struct dlm_master_list_entry *mle) | |
134 | { | |
135 | int i = 0, refs; | |
136 | char *type; | |
137 | char attached; | |
138 | u8 master; | |
139 | unsigned int namelen; | |
140 | const char *name; | |
141 | struct kref *k; | |
142 | ||
143 | k = &mle->mle_refs; | |
144 | if (mle->type == DLM_MLE_BLOCK) | |
145 | type = "BLK"; | |
146 | else if (mle->type == DLM_MLE_MASTER) | |
147 | type = "MAS"; | |
148 | else | |
149 | type = "MIG"; | |
150 | refs = atomic_read(&k->refcount); | |
151 | master = mle->master; | |
152 | attached = (list_empty(&mle->hb_events) ? 'N' : 'Y'); | |
153 | ||
154 | if (mle->type != DLM_MLE_MASTER) { | |
155 | namelen = mle->u.name.len; | |
156 | name = mle->u.name.name; | |
157 | } else { | |
158 | namelen = mle->u.res->lockname.len; | |
159 | name = mle->u.res->lockname.name; | |
160 | } | |
161 | ||
162 | mlog(ML_NOTICE, " #%3d: %3s %3d %3u %3u %c (%d)%.*s\n", | |
163 | i, type, refs, master, mle->new_master, attached, | |
164 | namelen, namelen, name); | |
165 | } | |
166 | ||
167 | static void dlm_dump_mles(struct dlm_ctxt *dlm) | |
168 | { | |
169 | struct dlm_master_list_entry *mle; | |
170 | struct list_head *iter; | |
171 | ||
172 | mlog(ML_NOTICE, "dumping all mles for domain %s:\n", dlm->name); | |
173 | mlog(ML_NOTICE, " ####: type refs owner new events? lockname nodemap votemap respmap maybemap\n"); | |
174 | spin_lock(&dlm->master_lock); | |
175 | list_for_each(iter, &dlm->master_list) { | |
176 | mle = list_entry(iter, struct dlm_master_list_entry, list); | |
177 | dlm_print_one_mle(mle); | |
178 | } | |
179 | spin_unlock(&dlm->master_lock); | |
180 | } | |
181 | ||
6714d8e8 KH |
182 | int dlm_dump_all_mles(const char __user *data, unsigned int len) |
183 | { | |
184 | struct list_head *iter; | |
185 | struct dlm_ctxt *dlm; | |
186 | ||
187 | spin_lock(&dlm_domain_lock); | |
188 | list_for_each(iter, &dlm_domains) { | |
189 | dlm = list_entry (iter, struct dlm_ctxt, list); | |
190 | mlog(ML_NOTICE, "found dlm: %p, name=%s\n", dlm, dlm->name); | |
191 | dlm_dump_mles(dlm); | |
192 | } | |
193 | spin_unlock(&dlm_domain_lock); | |
194 | return len; | |
195 | } | |
196 | EXPORT_SYMBOL_GPL(dlm_dump_all_mles); | |
197 | ||
198 | #endif /* 0 */ | |
199 | ||
200 | ||
201 | static kmem_cache_t *dlm_mle_cache = NULL; | |
202 | ||
203 | ||
204 | static void dlm_mle_release(struct kref *kref); | |
205 | static void dlm_init_mle(struct dlm_master_list_entry *mle, | |
206 | enum dlm_mle_type type, | |
207 | struct dlm_ctxt *dlm, | |
208 | struct dlm_lock_resource *res, | |
209 | const char *name, | |
210 | unsigned int namelen); | |
211 | static void dlm_put_mle(struct dlm_master_list_entry *mle); | |
212 | static void __dlm_put_mle(struct dlm_master_list_entry *mle); | |
213 | static int dlm_find_mle(struct dlm_ctxt *dlm, | |
214 | struct dlm_master_list_entry **mle, | |
215 | char *name, unsigned int namelen); | |
216 | ||
217 | static int dlm_do_master_request(struct dlm_master_list_entry *mle, int to); | |
218 | ||
219 | ||
220 | static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm, | |
221 | struct dlm_lock_resource *res, | |
222 | struct dlm_master_list_entry *mle, | |
223 | int *blocked); | |
224 | static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm, | |
225 | struct dlm_lock_resource *res, | |
226 | struct dlm_master_list_entry *mle, | |
227 | int blocked); | |
228 | static int dlm_add_migration_mle(struct dlm_ctxt *dlm, | |
229 | struct dlm_lock_resource *res, | |
230 | struct dlm_master_list_entry *mle, | |
231 | struct dlm_master_list_entry **oldmle, | |
232 | const char *name, unsigned int namelen, | |
233 | u8 new_master, u8 master); | |
234 | ||
235 | static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm, | |
236 | struct dlm_lock_resource *res); | |
237 | static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm, | |
238 | struct dlm_lock_resource *res); | |
239 | static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm, | |
240 | struct dlm_lock_resource *res, | |
241 | u8 target); | |
242 | ||
243 | ||
244 | int dlm_is_host_down(int errno) | |
245 | { | |
246 | switch (errno) { | |
247 | case -EBADF: | |
248 | case -ECONNREFUSED: | |
249 | case -ENOTCONN: | |
250 | case -ECONNRESET: | |
251 | case -EPIPE: | |
252 | case -EHOSTDOWN: | |
253 | case -EHOSTUNREACH: | |
254 | case -ETIMEDOUT: | |
255 | case -ECONNABORTED: | |
256 | case -ENETDOWN: | |
257 | case -ENETUNREACH: | |
258 | case -ENETRESET: | |
259 | case -ESHUTDOWN: | |
260 | case -ENOPROTOOPT: | |
261 | case -EINVAL: /* if returned from our tcp code, | |
262 | this means there is no socket */ | |
263 | return 1; | |
264 | } | |
265 | return 0; | |
266 | } | |
267 | ||
268 | ||
269 | /* | |
270 | * MASTER LIST FUNCTIONS | |
271 | */ | |
272 | ||
273 | ||
274 | /* | |
275 | * regarding master list entries and heartbeat callbacks: | |
276 | * | |
277 | * in order to avoid sleeping and allocation that occurs in | |
278 | * heartbeat, master list entries are simply attached to the | |
279 | * dlm's established heartbeat callbacks. the mle is attached | |
280 | * when it is created, and since the dlm->spinlock is held at | |
281 | * that time, any heartbeat event will be properly discovered | |
282 | * by the mle. the mle needs to be detached from the | |
283 | * dlm->mle_hb_events list as soon as heartbeat events are no | |
284 | * longer useful to the mle, and before the mle is freed. | |
285 | * | |
286 | * as a general rule, heartbeat events are no longer needed by | |
287 | * the mle once an "answer" regarding the lock master has been | |
288 | * received. | |
289 | */ | |
290 | static inline void __dlm_mle_attach_hb_events(struct dlm_ctxt *dlm, | |
291 | struct dlm_master_list_entry *mle) | |
292 | { | |
293 | assert_spin_locked(&dlm->spinlock); | |
294 | ||
295 | list_add_tail(&mle->hb_events, &dlm->mle_hb_events); | |
296 | } | |
297 | ||
298 | ||
299 | static inline void __dlm_mle_detach_hb_events(struct dlm_ctxt *dlm, | |
300 | struct dlm_master_list_entry *mle) | |
301 | { | |
302 | if (!list_empty(&mle->hb_events)) | |
303 | list_del_init(&mle->hb_events); | |
304 | } | |
305 | ||
306 | ||
307 | static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm, | |
308 | struct dlm_master_list_entry *mle) | |
309 | { | |
310 | spin_lock(&dlm->spinlock); | |
311 | __dlm_mle_detach_hb_events(dlm, mle); | |
312 | spin_unlock(&dlm->spinlock); | |
313 | } | |
314 | ||
315 | /* remove from list and free */ | |
316 | static void __dlm_put_mle(struct dlm_master_list_entry *mle) | |
317 | { | |
318 | struct dlm_ctxt *dlm; | |
319 | dlm = mle->dlm; | |
320 | ||
321 | assert_spin_locked(&dlm->spinlock); | |
322 | assert_spin_locked(&dlm->master_lock); | |
323 | BUG_ON(!atomic_read(&mle->mle_refs.refcount)); | |
324 | ||
325 | kref_put(&mle->mle_refs, dlm_mle_release); | |
326 | } | |
327 | ||
328 | ||
329 | /* must not have any spinlocks coming in */ | |
330 | static void dlm_put_mle(struct dlm_master_list_entry *mle) | |
331 | { | |
332 | struct dlm_ctxt *dlm; | |
333 | dlm = mle->dlm; | |
334 | ||
335 | spin_lock(&dlm->spinlock); | |
336 | spin_lock(&dlm->master_lock); | |
337 | __dlm_put_mle(mle); | |
338 | spin_unlock(&dlm->master_lock); | |
339 | spin_unlock(&dlm->spinlock); | |
340 | } | |
341 | ||
342 | static inline void dlm_get_mle(struct dlm_master_list_entry *mle) | |
343 | { | |
344 | kref_get(&mle->mle_refs); | |
345 | } | |
346 | ||
347 | static void dlm_init_mle(struct dlm_master_list_entry *mle, | |
348 | enum dlm_mle_type type, | |
349 | struct dlm_ctxt *dlm, | |
350 | struct dlm_lock_resource *res, | |
351 | const char *name, | |
352 | unsigned int namelen) | |
353 | { | |
354 | assert_spin_locked(&dlm->spinlock); | |
355 | ||
356 | mle->dlm = dlm; | |
357 | mle->type = type; | |
358 | INIT_LIST_HEAD(&mle->list); | |
359 | INIT_LIST_HEAD(&mle->hb_events); | |
360 | memset(mle->maybe_map, 0, sizeof(mle->maybe_map)); | |
361 | spin_lock_init(&mle->spinlock); | |
362 | init_waitqueue_head(&mle->wq); | |
363 | atomic_set(&mle->woken, 0); | |
364 | kref_init(&mle->mle_refs); | |
365 | memset(mle->response_map, 0, sizeof(mle->response_map)); | |
366 | mle->master = O2NM_MAX_NODES; | |
367 | mle->new_master = O2NM_MAX_NODES; | |
368 | ||
369 | if (mle->type == DLM_MLE_MASTER) { | |
370 | BUG_ON(!res); | |
371 | mle->u.res = res; | |
372 | } else if (mle->type == DLM_MLE_BLOCK) { | |
373 | BUG_ON(!name); | |
374 | memcpy(mle->u.name.name, name, namelen); | |
375 | mle->u.name.len = namelen; | |
376 | } else /* DLM_MLE_MIGRATION */ { | |
377 | BUG_ON(!name); | |
378 | memcpy(mle->u.name.name, name, namelen); | |
379 | mle->u.name.len = namelen; | |
380 | } | |
381 | ||
382 | /* copy off the node_map and register hb callbacks on our copy */ | |
383 | memcpy(mle->node_map, dlm->domain_map, sizeof(mle->node_map)); | |
384 | memcpy(mle->vote_map, dlm->domain_map, sizeof(mle->vote_map)); | |
385 | clear_bit(dlm->node_num, mle->vote_map); | |
386 | clear_bit(dlm->node_num, mle->node_map); | |
387 | ||
388 | /* attach the mle to the domain node up/down events */ | |
389 | __dlm_mle_attach_hb_events(dlm, mle); | |
390 | } | |
391 | ||
392 | ||
393 | /* returns 1 if found, 0 if not */ | |
394 | static int dlm_find_mle(struct dlm_ctxt *dlm, | |
395 | struct dlm_master_list_entry **mle, | |
396 | char *name, unsigned int namelen) | |
397 | { | |
398 | struct dlm_master_list_entry *tmpmle; | |
399 | struct list_head *iter; | |
400 | ||
401 | assert_spin_locked(&dlm->master_lock); | |
402 | ||
403 | list_for_each(iter, &dlm->master_list) { | |
404 | tmpmle = list_entry(iter, struct dlm_master_list_entry, list); | |
405 | if (!dlm_mle_equal(dlm, tmpmle, name, namelen)) | |
406 | continue; | |
407 | dlm_get_mle(tmpmle); | |
408 | *mle = tmpmle; | |
409 | return 1; | |
410 | } | |
411 | return 0; | |
412 | } | |
413 | ||
414 | void dlm_hb_event_notify_attached(struct dlm_ctxt *dlm, int idx, int node_up) | |
415 | { | |
416 | struct dlm_master_list_entry *mle; | |
417 | struct list_head *iter; | |
418 | ||
419 | assert_spin_locked(&dlm->spinlock); | |
420 | ||
421 | list_for_each(iter, &dlm->mle_hb_events) { | |
422 | mle = list_entry(iter, struct dlm_master_list_entry, | |
423 | hb_events); | |
424 | if (node_up) | |
425 | dlm_mle_node_up(dlm, mle, NULL, idx); | |
426 | else | |
427 | dlm_mle_node_down(dlm, mle, NULL, idx); | |
428 | } | |
429 | } | |
430 | ||
431 | static void dlm_mle_node_down(struct dlm_ctxt *dlm, | |
432 | struct dlm_master_list_entry *mle, | |
433 | struct o2nm_node *node, int idx) | |
434 | { | |
435 | spin_lock(&mle->spinlock); | |
436 | ||
437 | if (!test_bit(idx, mle->node_map)) | |
438 | mlog(0, "node %u already removed from nodemap!\n", idx); | |
439 | else | |
440 | clear_bit(idx, mle->node_map); | |
441 | ||
442 | spin_unlock(&mle->spinlock); | |
443 | } | |
444 | ||
445 | static void dlm_mle_node_up(struct dlm_ctxt *dlm, | |
446 | struct dlm_master_list_entry *mle, | |
447 | struct o2nm_node *node, int idx) | |
448 | { | |
449 | spin_lock(&mle->spinlock); | |
450 | ||
451 | if (test_bit(idx, mle->node_map)) | |
452 | mlog(0, "node %u already in node map!\n", idx); | |
453 | else | |
454 | set_bit(idx, mle->node_map); | |
455 | ||
456 | spin_unlock(&mle->spinlock); | |
457 | } | |
458 | ||
459 | ||
460 | int dlm_init_mle_cache(void) | |
461 | { | |
462 | dlm_mle_cache = kmem_cache_create("dlm_mle_cache", | |
463 | sizeof(struct dlm_master_list_entry), | |
464 | 0, SLAB_HWCACHE_ALIGN, | |
465 | NULL, NULL); | |
466 | if (dlm_mle_cache == NULL) | |
467 | return -ENOMEM; | |
468 | return 0; | |
469 | } | |
470 | ||
471 | void dlm_destroy_mle_cache(void) | |
472 | { | |
473 | if (dlm_mle_cache) | |
474 | kmem_cache_destroy(dlm_mle_cache); | |
475 | } | |
476 | ||
477 | static void dlm_mle_release(struct kref *kref) | |
478 | { | |
479 | struct dlm_master_list_entry *mle; | |
480 | struct dlm_ctxt *dlm; | |
481 | ||
482 | mlog_entry_void(); | |
483 | ||
484 | mle = container_of(kref, struct dlm_master_list_entry, mle_refs); | |
485 | dlm = mle->dlm; | |
486 | ||
487 | if (mle->type != DLM_MLE_MASTER) { | |
488 | mlog(0, "calling mle_release for %.*s, type %d\n", | |
489 | mle->u.name.len, mle->u.name.name, mle->type); | |
490 | } else { | |
491 | mlog(0, "calling mle_release for %.*s, type %d\n", | |
492 | mle->u.res->lockname.len, | |
493 | mle->u.res->lockname.name, mle->type); | |
494 | } | |
495 | assert_spin_locked(&dlm->spinlock); | |
496 | assert_spin_locked(&dlm->master_lock); | |
497 | ||
498 | /* remove from list if not already */ | |
499 | if (!list_empty(&mle->list)) | |
500 | list_del_init(&mle->list); | |
501 | ||
502 | /* detach the mle from the domain node up/down events */ | |
503 | __dlm_mle_detach_hb_events(dlm, mle); | |
504 | ||
505 | /* NOTE: kfree under spinlock here. | |
506 | * if this is bad, we can move this to a freelist. */ | |
507 | kmem_cache_free(dlm_mle_cache, mle); | |
508 | } | |
509 | ||
510 | ||
511 | /* | |
512 | * LOCK RESOURCE FUNCTIONS | |
513 | */ | |
514 | ||
515 | static void dlm_set_lockres_owner(struct dlm_ctxt *dlm, | |
516 | struct dlm_lock_resource *res, | |
517 | u8 owner) | |
518 | { | |
519 | assert_spin_locked(&res->spinlock); | |
520 | ||
521 | mlog_entry("%.*s, %u\n", res->lockname.len, res->lockname.name, owner); | |
522 | ||
523 | if (owner == dlm->node_num) | |
524 | atomic_inc(&dlm->local_resources); | |
525 | else if (owner == DLM_LOCK_RES_OWNER_UNKNOWN) | |
526 | atomic_inc(&dlm->unknown_resources); | |
527 | else | |
528 | atomic_inc(&dlm->remote_resources); | |
529 | ||
530 | res->owner = owner; | |
531 | } | |
532 | ||
533 | void dlm_change_lockres_owner(struct dlm_ctxt *dlm, | |
534 | struct dlm_lock_resource *res, u8 owner) | |
535 | { | |
536 | assert_spin_locked(&res->spinlock); | |
537 | ||
538 | if (owner == res->owner) | |
539 | return; | |
540 | ||
541 | if (res->owner == dlm->node_num) | |
542 | atomic_dec(&dlm->local_resources); | |
543 | else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) | |
544 | atomic_dec(&dlm->unknown_resources); | |
545 | else | |
546 | atomic_dec(&dlm->remote_resources); | |
547 | ||
548 | dlm_set_lockres_owner(dlm, res, owner); | |
549 | } | |
550 | ||
551 | ||
552 | static void dlm_lockres_release(struct kref *kref) | |
553 | { | |
554 | struct dlm_lock_resource *res; | |
555 | ||
556 | res = container_of(kref, struct dlm_lock_resource, refs); | |
557 | ||
558 | /* This should not happen -- all lockres' have a name | |
559 | * associated with them at init time. */ | |
560 | BUG_ON(!res->lockname.name); | |
561 | ||
562 | mlog(0, "destroying lockres %.*s\n", res->lockname.len, | |
563 | res->lockname.name); | |
564 | ||
565 | /* By the time we're ready to blow this guy away, we shouldn't | |
566 | * be on any lists. */ | |
81f2094a | 567 | BUG_ON(!hlist_unhashed(&res->hash_node)); |
6714d8e8 KH |
568 | BUG_ON(!list_empty(&res->granted)); |
569 | BUG_ON(!list_empty(&res->converting)); | |
570 | BUG_ON(!list_empty(&res->blocked)); | |
571 | BUG_ON(!list_empty(&res->dirty)); | |
572 | BUG_ON(!list_empty(&res->recovering)); | |
573 | BUG_ON(!list_empty(&res->purge)); | |
574 | ||
575 | kfree(res->lockname.name); | |
576 | ||
577 | kfree(res); | |
578 | } | |
579 | ||
580 | void dlm_lockres_get(struct dlm_lock_resource *res) | |
581 | { | |
582 | kref_get(&res->refs); | |
583 | } | |
584 | ||
585 | void dlm_lockres_put(struct dlm_lock_resource *res) | |
586 | { | |
587 | kref_put(&res->refs, dlm_lockres_release); | |
588 | } | |
589 | ||
590 | static void dlm_init_lockres(struct dlm_ctxt *dlm, | |
591 | struct dlm_lock_resource *res, | |
592 | const char *name, unsigned int namelen) | |
593 | { | |
594 | char *qname; | |
595 | ||
596 | /* If we memset here, we lose our reference to the kmalloc'd | |
597 | * res->lockname.name, so be sure to init every field | |
598 | * correctly! */ | |
599 | ||
600 | qname = (char *) res->lockname.name; | |
601 | memcpy(qname, name, namelen); | |
602 | ||
603 | res->lockname.len = namelen; | |
604 | res->lockname.hash = full_name_hash(name, namelen); | |
605 | ||
606 | init_waitqueue_head(&res->wq); | |
607 | spin_lock_init(&res->spinlock); | |
81f2094a | 608 | INIT_HLIST_NODE(&res->hash_node); |
6714d8e8 KH |
609 | INIT_LIST_HEAD(&res->granted); |
610 | INIT_LIST_HEAD(&res->converting); | |
611 | INIT_LIST_HEAD(&res->blocked); | |
612 | INIT_LIST_HEAD(&res->dirty); | |
613 | INIT_LIST_HEAD(&res->recovering); | |
614 | INIT_LIST_HEAD(&res->purge); | |
615 | atomic_set(&res->asts_reserved, 0); | |
616 | res->migration_pending = 0; | |
617 | ||
618 | kref_init(&res->refs); | |
619 | ||
620 | /* just for consistency */ | |
621 | spin_lock(&res->spinlock); | |
622 | dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN); | |
623 | spin_unlock(&res->spinlock); | |
624 | ||
625 | res->state = DLM_LOCK_RES_IN_PROGRESS; | |
626 | ||
627 | res->last_used = 0; | |
628 | ||
629 | memset(res->lvb, 0, DLM_LVB_LEN); | |
630 | } | |
631 | ||
632 | struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm, | |
633 | const char *name, | |
634 | unsigned int namelen) | |
635 | { | |
636 | struct dlm_lock_resource *res; | |
637 | ||
638 | res = kmalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL); | |
639 | if (!res) | |
640 | return NULL; | |
641 | ||
642 | res->lockname.name = kmalloc(namelen, GFP_KERNEL); | |
643 | if (!res->lockname.name) { | |
644 | kfree(res); | |
645 | return NULL; | |
646 | } | |
647 | ||
648 | dlm_init_lockres(dlm, res, name, namelen); | |
649 | return res; | |
650 | } | |
651 | ||
652 | /* | |
653 | * lookup a lock resource by name. | |
654 | * may already exist in the hashtable. | |
655 | * lockid is null terminated | |
656 | * | |
657 | * if not, allocate enough for the lockres and for | |
658 | * the temporary structure used in doing the mastering. | |
659 | * | |
660 | * also, do a lookup in the dlm->master_list to see | |
661 | * if another node has begun mastering the same lock. | |
662 | * if so, there should be a block entry in there | |
663 | * for this name, and we should *not* attempt to master | |
664 | * the lock here. need to wait around for that node | |
665 | * to assert_master (or die). | |
666 | * | |
667 | */ | |
668 | struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm, | |
669 | const char *lockid, | |
670 | int flags) | |
671 | { | |
672 | struct dlm_lock_resource *tmpres=NULL, *res=NULL; | |
673 | struct dlm_master_list_entry *mle = NULL; | |
674 | struct dlm_master_list_entry *alloc_mle = NULL; | |
675 | int blocked = 0; | |
676 | int ret, nodenum; | |
677 | struct dlm_node_iter iter; | |
678 | unsigned int namelen; | |
679 | int tries = 0; | |
680 | ||
681 | BUG_ON(!lockid); | |
682 | ||
683 | namelen = strlen(lockid); | |
684 | ||
685 | mlog(0, "get lockres %s (len %d)\n", lockid, namelen); | |
686 | ||
687 | lookup: | |
688 | spin_lock(&dlm->spinlock); | |
689 | tmpres = __dlm_lookup_lockres(dlm, lockid, namelen); | |
690 | if (tmpres) { | |
691 | spin_unlock(&dlm->spinlock); | |
692 | mlog(0, "found in hash!\n"); | |
693 | if (res) | |
694 | dlm_lockres_put(res); | |
695 | res = tmpres; | |
696 | goto leave; | |
697 | } | |
698 | ||
699 | if (!res) { | |
700 | spin_unlock(&dlm->spinlock); | |
701 | mlog(0, "allocating a new resource\n"); | |
702 | /* nothing found and we need to allocate one. */ | |
703 | alloc_mle = (struct dlm_master_list_entry *) | |
704 | kmem_cache_alloc(dlm_mle_cache, GFP_KERNEL); | |
705 | if (!alloc_mle) | |
706 | goto leave; | |
707 | res = dlm_new_lockres(dlm, lockid, namelen); | |
708 | if (!res) | |
709 | goto leave; | |
710 | goto lookup; | |
711 | } | |
712 | ||
713 | mlog(0, "no lockres found, allocated our own: %p\n", res); | |
714 | ||
715 | if (flags & LKM_LOCAL) { | |
716 | /* caller knows it's safe to assume it's not mastered elsewhere | |
717 | * DONE! return right away */ | |
718 | spin_lock(&res->spinlock); | |
719 | dlm_change_lockres_owner(dlm, res, dlm->node_num); | |
720 | __dlm_insert_lockres(dlm, res); | |
721 | spin_unlock(&res->spinlock); | |
722 | spin_unlock(&dlm->spinlock); | |
723 | /* lockres still marked IN_PROGRESS */ | |
724 | goto wake_waiters; | |
725 | } | |
726 | ||
727 | /* check master list to see if another node has started mastering it */ | |
728 | spin_lock(&dlm->master_lock); | |
729 | ||
730 | /* if we found a block, wait for lock to be mastered by another node */ | |
731 | blocked = dlm_find_mle(dlm, &mle, (char *)lockid, namelen); | |
732 | if (blocked) { | |
733 | if (mle->type == DLM_MLE_MASTER) { | |
734 | mlog(ML_ERROR, "master entry for nonexistent lock!\n"); | |
735 | BUG(); | |
736 | } else if (mle->type == DLM_MLE_MIGRATION) { | |
737 | /* migration is in progress! */ | |
738 | /* the good news is that we now know the | |
739 | * "current" master (mle->master). */ | |
740 | ||
741 | spin_unlock(&dlm->master_lock); | |
742 | assert_spin_locked(&dlm->spinlock); | |
743 | ||
744 | /* set the lockres owner and hash it */ | |
745 | spin_lock(&res->spinlock); | |
746 | dlm_set_lockres_owner(dlm, res, mle->master); | |
747 | __dlm_insert_lockres(dlm, res); | |
748 | spin_unlock(&res->spinlock); | |
749 | spin_unlock(&dlm->spinlock); | |
750 | ||
751 | /* master is known, detach */ | |
752 | dlm_mle_detach_hb_events(dlm, mle); | |
753 | dlm_put_mle(mle); | |
754 | mle = NULL; | |
755 | goto wake_waiters; | |
756 | } | |
757 | } else { | |
758 | /* go ahead and try to master lock on this node */ | |
759 | mle = alloc_mle; | |
760 | /* make sure this does not get freed below */ | |
761 | alloc_mle = NULL; | |
762 | dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0); | |
763 | set_bit(dlm->node_num, mle->maybe_map); | |
764 | list_add(&mle->list, &dlm->master_list); | |
765 | } | |
766 | ||
767 | /* at this point there is either a DLM_MLE_BLOCK or a | |
768 | * DLM_MLE_MASTER on the master list, so it's safe to add the | |
769 | * lockres to the hashtable. anyone who finds the lock will | |
770 | * still have to wait on the IN_PROGRESS. */ | |
771 | ||
772 | /* finally add the lockres to its hash bucket */ | |
773 | __dlm_insert_lockres(dlm, res); | |
774 | /* get an extra ref on the mle in case this is a BLOCK | |
775 | * if so, the creator of the BLOCK may try to put the last | |
776 | * ref at this time in the assert master handler, so we | |
777 | * need an extra one to keep from a bad ptr deref. */ | |
778 | dlm_get_mle(mle); | |
779 | spin_unlock(&dlm->master_lock); | |
780 | spin_unlock(&dlm->spinlock); | |
781 | ||
782 | /* must wait for lock to be mastered elsewhere */ | |
783 | if (blocked) | |
784 | goto wait; | |
785 | ||
786 | redo_request: | |
787 | ret = -EINVAL; | |
788 | dlm_node_iter_init(mle->vote_map, &iter); | |
789 | while ((nodenum = dlm_node_iter_next(&iter)) >= 0) { | |
790 | ret = dlm_do_master_request(mle, nodenum); | |
791 | if (ret < 0) | |
792 | mlog_errno(ret); | |
793 | if (mle->master != O2NM_MAX_NODES) { | |
794 | /* found a master ! */ | |
9c6510a5 KH |
795 | if (mle->master <= nodenum) |
796 | break; | |
797 | /* if our master request has not reached the master | |
798 | * yet, keep going until it does. this is how the | |
799 | * master will know that asserts are needed back to | |
800 | * the lower nodes. */ | |
801 | mlog(0, "%s:%.*s: requests only up to %u but master " | |
802 | "is %u, keep going\n", dlm->name, namelen, | |
803 | lockid, nodenum, mle->master); | |
6714d8e8 KH |
804 | } |
805 | } | |
806 | ||
807 | wait: | |
808 | /* keep going until the response map includes all nodes */ | |
809 | ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked); | |
810 | if (ret < 0) { | |
811 | mlog(0, "%s:%.*s: node map changed, redo the " | |
812 | "master request now, blocked=%d\n", | |
813 | dlm->name, res->lockname.len, | |
814 | res->lockname.name, blocked); | |
815 | if (++tries > 20) { | |
816 | mlog(ML_ERROR, "%s:%.*s: spinning on " | |
817 | "dlm_wait_for_lock_mastery, blocked=%d\n", | |
818 | dlm->name, res->lockname.len, | |
819 | res->lockname.name, blocked); | |
820 | dlm_print_one_lock_resource(res); | |
821 | /* dlm_print_one_mle(mle); */ | |
822 | tries = 0; | |
823 | } | |
824 | goto redo_request; | |
825 | } | |
826 | ||
827 | mlog(0, "lockres mastered by %u\n", res->owner); | |
828 | /* make sure we never continue without this */ | |
829 | BUG_ON(res->owner == O2NM_MAX_NODES); | |
830 | ||
831 | /* master is known, detach if not already detached */ | |
832 | dlm_mle_detach_hb_events(dlm, mle); | |
833 | dlm_put_mle(mle); | |
834 | /* put the extra ref */ | |
835 | dlm_put_mle(mle); | |
836 | ||
837 | wake_waiters: | |
838 | spin_lock(&res->spinlock); | |
839 | res->state &= ~DLM_LOCK_RES_IN_PROGRESS; | |
840 | spin_unlock(&res->spinlock); | |
841 | wake_up(&res->wq); | |
842 | ||
843 | leave: | |
844 | /* need to free the unused mle */ | |
845 | if (alloc_mle) | |
846 | kmem_cache_free(dlm_mle_cache, alloc_mle); | |
847 | ||
848 | return res; | |
849 | } | |
850 | ||
851 | ||
852 | #define DLM_MASTERY_TIMEOUT_MS 5000 | |
853 | ||
854 | static int dlm_wait_for_lock_mastery(struct dlm_ctxt *dlm, | |
855 | struct dlm_lock_resource *res, | |
856 | struct dlm_master_list_entry *mle, | |
857 | int *blocked) | |
858 | { | |
859 | u8 m; | |
860 | int ret, bit; | |
861 | int map_changed, voting_done; | |
862 | int assert, sleep; | |
863 | ||
864 | recheck: | |
865 | ret = 0; | |
866 | assert = 0; | |
867 | ||
868 | /* check if another node has already become the owner */ | |
869 | spin_lock(&res->spinlock); | |
870 | if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) { | |
9c6510a5 KH |
871 | mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name, |
872 | res->lockname.len, res->lockname.name, res->owner); | |
6714d8e8 | 873 | spin_unlock(&res->spinlock); |
9c6510a5 KH |
874 | /* this will cause the master to re-assert across |
875 | * the whole cluster, freeing up mles */ | |
876 | ret = dlm_do_master_request(mle, res->owner); | |
877 | if (ret < 0) { | |
878 | /* give recovery a chance to run */ | |
879 | mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret); | |
880 | msleep(500); | |
881 | goto recheck; | |
882 | } | |
883 | ret = 0; | |
6714d8e8 KH |
884 | goto leave; |
885 | } | |
886 | spin_unlock(&res->spinlock); | |
887 | ||
888 | spin_lock(&mle->spinlock); | |
889 | m = mle->master; | |
890 | map_changed = (memcmp(mle->vote_map, mle->node_map, | |
891 | sizeof(mle->vote_map)) != 0); | |
892 | voting_done = (memcmp(mle->vote_map, mle->response_map, | |
893 | sizeof(mle->vote_map)) == 0); | |
894 | ||
895 | /* restart if we hit any errors */ | |
896 | if (map_changed) { | |
897 | int b; | |
898 | mlog(0, "%s: %.*s: node map changed, restarting\n", | |
899 | dlm->name, res->lockname.len, res->lockname.name); | |
900 | ret = dlm_restart_lock_mastery(dlm, res, mle, *blocked); | |
901 | b = (mle->type == DLM_MLE_BLOCK); | |
902 | if ((*blocked && !b) || (!*blocked && b)) { | |
903 | mlog(0, "%s:%.*s: status change: old=%d new=%d\n", | |
904 | dlm->name, res->lockname.len, res->lockname.name, | |
905 | *blocked, b); | |
906 | *blocked = b; | |
907 | } | |
908 | spin_unlock(&mle->spinlock); | |
909 | if (ret < 0) { | |
910 | mlog_errno(ret); | |
911 | goto leave; | |
912 | } | |
913 | mlog(0, "%s:%.*s: restart lock mastery succeeded, " | |
914 | "rechecking now\n", dlm->name, res->lockname.len, | |
915 | res->lockname.name); | |
916 | goto recheck; | |
917 | } | |
918 | ||
919 | if (m != O2NM_MAX_NODES) { | |
920 | /* another node has done an assert! | |
921 | * all done! */ | |
922 | sleep = 0; | |
923 | } else { | |
924 | sleep = 1; | |
925 | /* have all nodes responded? */ | |
926 | if (voting_done && !*blocked) { | |
927 | bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0); | |
928 | if (dlm->node_num <= bit) { | |
929 | /* my node number is lowest. | |
930 | * now tell other nodes that I am | |
931 | * mastering this. */ | |
932 | mle->master = dlm->node_num; | |
933 | assert = 1; | |
934 | sleep = 0; | |
935 | } | |
936 | /* if voting is done, but we have not received | |
937 | * an assert master yet, we must sleep */ | |
938 | } | |
939 | } | |
940 | ||
941 | spin_unlock(&mle->spinlock); | |
942 | ||
943 | /* sleep if we haven't finished voting yet */ | |
944 | if (sleep) { | |
945 | unsigned long timeo = msecs_to_jiffies(DLM_MASTERY_TIMEOUT_MS); | |
946 | ||
947 | /* | |
948 | if (atomic_read(&mle->mle_refs.refcount) < 2) | |
949 | mlog(ML_ERROR, "mle (%p) refs=%d, name=%.*s\n", mle, | |
950 | atomic_read(&mle->mle_refs.refcount), | |
951 | res->lockname.len, res->lockname.name); | |
952 | */ | |
953 | atomic_set(&mle->woken, 0); | |
954 | (void)wait_event_timeout(mle->wq, | |
955 | (atomic_read(&mle->woken) == 1), | |
956 | timeo); | |
957 | if (res->owner == O2NM_MAX_NODES) { | |
958 | mlog(0, "waiting again\n"); | |
959 | goto recheck; | |
960 | } | |
961 | mlog(0, "done waiting, master is %u\n", res->owner); | |
962 | ret = 0; | |
963 | goto leave; | |
964 | } | |
965 | ||
966 | ret = 0; /* done */ | |
967 | if (assert) { | |
968 | m = dlm->node_num; | |
969 | mlog(0, "about to master %.*s here, this=%u\n", | |
970 | res->lockname.len, res->lockname.name, m); | |
971 | ret = dlm_do_assert_master(dlm, res->lockname.name, | |
972 | res->lockname.len, mle->vote_map, 0); | |
973 | if (ret) { | |
974 | /* This is a failure in the network path, | |
975 | * not in the response to the assert_master | |
976 | * (any nonzero response is a BUG on this node). | |
977 | * Most likely a socket just got disconnected | |
978 | * due to node death. */ | |
979 | mlog_errno(ret); | |
980 | } | |
981 | /* no longer need to restart lock mastery. | |
982 | * all living nodes have been contacted. */ | |
983 | ret = 0; | |
984 | } | |
985 | ||
986 | /* set the lockres owner */ | |
987 | spin_lock(&res->spinlock); | |
988 | dlm_change_lockres_owner(dlm, res, m); | |
989 | spin_unlock(&res->spinlock); | |
990 | ||
991 | leave: | |
992 | return ret; | |
993 | } | |
994 | ||
995 | struct dlm_bitmap_diff_iter | |
996 | { | |
997 | int curnode; | |
998 | unsigned long *orig_bm; | |
999 | unsigned long *cur_bm; | |
1000 | unsigned long diff_bm[BITS_TO_LONGS(O2NM_MAX_NODES)]; | |
1001 | }; | |
1002 | ||
1003 | enum dlm_node_state_change | |
1004 | { | |
1005 | NODE_DOWN = -1, | |
1006 | NODE_NO_CHANGE = 0, | |
1007 | NODE_UP | |
1008 | }; | |
1009 | ||
1010 | static void dlm_bitmap_diff_iter_init(struct dlm_bitmap_diff_iter *iter, | |
1011 | unsigned long *orig_bm, | |
1012 | unsigned long *cur_bm) | |
1013 | { | |
1014 | unsigned long p1, p2; | |
1015 | int i; | |
1016 | ||
1017 | iter->curnode = -1; | |
1018 | iter->orig_bm = orig_bm; | |
1019 | iter->cur_bm = cur_bm; | |
1020 | ||
1021 | for (i = 0; i < BITS_TO_LONGS(O2NM_MAX_NODES); i++) { | |
1022 | p1 = *(iter->orig_bm + i); | |
1023 | p2 = *(iter->cur_bm + i); | |
1024 | iter->diff_bm[i] = (p1 & ~p2) | (p2 & ~p1); | |
1025 | } | |
1026 | } | |
1027 | ||
1028 | static int dlm_bitmap_diff_iter_next(struct dlm_bitmap_diff_iter *iter, | |
1029 | enum dlm_node_state_change *state) | |
1030 | { | |
1031 | int bit; | |
1032 | ||
1033 | if (iter->curnode >= O2NM_MAX_NODES) | |
1034 | return -ENOENT; | |
1035 | ||
1036 | bit = find_next_bit(iter->diff_bm, O2NM_MAX_NODES, | |
1037 | iter->curnode+1); | |
1038 | if (bit >= O2NM_MAX_NODES) { | |
1039 | iter->curnode = O2NM_MAX_NODES; | |
1040 | return -ENOENT; | |
1041 | } | |
1042 | ||
1043 | /* if it was there in the original then this node died */ | |
1044 | if (test_bit(bit, iter->orig_bm)) | |
1045 | *state = NODE_DOWN; | |
1046 | else | |
1047 | *state = NODE_UP; | |
1048 | ||
1049 | iter->curnode = bit; | |
1050 | return bit; | |
1051 | } | |
1052 | ||
1053 | ||
1054 | static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm, | |
1055 | struct dlm_lock_resource *res, | |
1056 | struct dlm_master_list_entry *mle, | |
1057 | int blocked) | |
1058 | { | |
1059 | struct dlm_bitmap_diff_iter bdi; | |
1060 | enum dlm_node_state_change sc; | |
1061 | int node; | |
1062 | int ret = 0; | |
1063 | ||
1064 | mlog(0, "something happened such that the " | |
1065 | "master process may need to be restarted!\n"); | |
1066 | ||
1067 | assert_spin_locked(&mle->spinlock); | |
1068 | ||
1069 | dlm_bitmap_diff_iter_init(&bdi, mle->vote_map, mle->node_map); | |
1070 | node = dlm_bitmap_diff_iter_next(&bdi, &sc); | |
1071 | while (node >= 0) { | |
1072 | if (sc == NODE_UP) { | |
e2faea4c KH |
1073 | /* a node came up. clear any old vote from |
1074 | * the response map and set it in the vote map | |
1075 | * then restart the mastery. */ | |
1076 | mlog(ML_NOTICE, "node %d up while restarting\n", node); | |
6714d8e8 KH |
1077 | |
1078 | /* redo the master request, but only for the new node */ | |
1079 | mlog(0, "sending request to new node\n"); | |
1080 | clear_bit(node, mle->response_map); | |
1081 | set_bit(node, mle->vote_map); | |
1082 | } else { | |
1083 | mlog(ML_ERROR, "node down! %d\n", node); | |
1084 | ||
1085 | /* if the node wasn't involved in mastery skip it, | |
1086 | * but clear it out from the maps so that it will | |
1087 | * not affect mastery of this lockres */ | |
1088 | clear_bit(node, mle->response_map); | |
1089 | clear_bit(node, mle->vote_map); | |
1090 | if (!test_bit(node, mle->maybe_map)) | |
1091 | goto next; | |
1092 | ||
1093 | /* if we're already blocked on lock mastery, and the | |
1094 | * dead node wasn't the expected master, or there is | |
1095 | * another node in the maybe_map, keep waiting */ | |
1096 | if (blocked) { | |
1097 | int lowest = find_next_bit(mle->maybe_map, | |
1098 | O2NM_MAX_NODES, 0); | |
1099 | ||
1100 | /* act like it was never there */ | |
1101 | clear_bit(node, mle->maybe_map); | |
1102 | ||
1103 | if (node != lowest) | |
1104 | goto next; | |
1105 | ||
1106 | mlog(ML_ERROR, "expected master %u died while " | |
1107 | "this node was blocked waiting on it!\n", | |
1108 | node); | |
1109 | lowest = find_next_bit(mle->maybe_map, | |
1110 | O2NM_MAX_NODES, | |
1111 | lowest+1); | |
1112 | if (lowest < O2NM_MAX_NODES) { | |
1113 | mlog(0, "still blocked. waiting " | |
1114 | "on %u now\n", lowest); | |
1115 | goto next; | |
1116 | } | |
1117 | ||
1118 | /* mle is an MLE_BLOCK, but there is now | |
1119 | * nothing left to block on. we need to return | |
1120 | * all the way back out and try again with | |
1121 | * an MLE_MASTER. dlm_do_local_recovery_cleanup | |
1122 | * has already run, so the mle refcount is ok */ | |
1123 | mlog(0, "no longer blocking. we can " | |
1124 | "try to master this here\n"); | |
1125 | mle->type = DLM_MLE_MASTER; | |
1126 | memset(mle->maybe_map, 0, | |
1127 | sizeof(mle->maybe_map)); | |
1128 | memset(mle->response_map, 0, | |
1129 | sizeof(mle->maybe_map)); | |
1130 | memcpy(mle->vote_map, mle->node_map, | |
1131 | sizeof(mle->node_map)); | |
1132 | mle->u.res = res; | |
1133 | set_bit(dlm->node_num, mle->maybe_map); | |
1134 | ||
1135 | ret = -EAGAIN; | |
1136 | goto next; | |
1137 | } | |
1138 | ||
1139 | clear_bit(node, mle->maybe_map); | |
1140 | if (node > dlm->node_num) | |
1141 | goto next; | |
1142 | ||
1143 | mlog(0, "dead node in map!\n"); | |
1144 | /* yuck. go back and re-contact all nodes | |
1145 | * in the vote_map, removing this node. */ | |
1146 | memset(mle->response_map, 0, | |
1147 | sizeof(mle->response_map)); | |
1148 | } | |
1149 | ret = -EAGAIN; | |
1150 | next: | |
1151 | node = dlm_bitmap_diff_iter_next(&bdi, &sc); | |
1152 | } | |
1153 | return ret; | |
1154 | } | |
1155 | ||
1156 | ||
1157 | /* | |
1158 | * DLM_MASTER_REQUEST_MSG | |
1159 | * | |
1160 | * returns: 0 on success, | |
1161 | * -errno on a network error | |
1162 | * | |
1163 | * on error, the caller should assume the target node is "dead" | |
1164 | * | |
1165 | */ | |
1166 | ||
1167 | static int dlm_do_master_request(struct dlm_master_list_entry *mle, int to) | |
1168 | { | |
1169 | struct dlm_ctxt *dlm = mle->dlm; | |
1170 | struct dlm_master_request request; | |
1171 | int ret, response=0, resend; | |
1172 | ||
1173 | memset(&request, 0, sizeof(request)); | |
1174 | request.node_idx = dlm->node_num; | |
1175 | ||
1176 | BUG_ON(mle->type == DLM_MLE_MIGRATION); | |
1177 | ||
1178 | if (mle->type != DLM_MLE_MASTER) { | |
1179 | request.namelen = mle->u.name.len; | |
1180 | memcpy(request.name, mle->u.name.name, request.namelen); | |
1181 | } else { | |
1182 | request.namelen = mle->u.res->lockname.len; | |
1183 | memcpy(request.name, mle->u.res->lockname.name, | |
1184 | request.namelen); | |
1185 | } | |
1186 | ||
1187 | again: | |
1188 | ret = o2net_send_message(DLM_MASTER_REQUEST_MSG, dlm->key, &request, | |
1189 | sizeof(request), to, &response); | |
1190 | if (ret < 0) { | |
1191 | if (ret == -ESRCH) { | |
1192 | /* should never happen */ | |
1193 | mlog(ML_ERROR, "TCP stack not ready!\n"); | |
1194 | BUG(); | |
1195 | } else if (ret == -EINVAL) { | |
1196 | mlog(ML_ERROR, "bad args passed to o2net!\n"); | |
1197 | BUG(); | |
1198 | } else if (ret == -ENOMEM) { | |
1199 | mlog(ML_ERROR, "out of memory while trying to send " | |
1200 | "network message! retrying\n"); | |
1201 | /* this is totally crude */ | |
1202 | msleep(50); | |
1203 | goto again; | |
1204 | } else if (!dlm_is_host_down(ret)) { | |
1205 | /* not a network error. bad. */ | |
1206 | mlog_errno(ret); | |
1207 | mlog(ML_ERROR, "unhandled error!"); | |
1208 | BUG(); | |
1209 | } | |
1210 | /* all other errors should be network errors, | |
1211 | * and likely indicate node death */ | |
1212 | mlog(ML_ERROR, "link to %d went down!\n", to); | |
1213 | goto out; | |
1214 | } | |
1215 | ||
1216 | ret = 0; | |
1217 | resend = 0; | |
1218 | spin_lock(&mle->spinlock); | |
1219 | switch (response) { | |
1220 | case DLM_MASTER_RESP_YES: | |
1221 | set_bit(to, mle->response_map); | |
1222 | mlog(0, "node %u is the master, response=YES\n", to); | |
1223 | mle->master = to; | |
1224 | break; | |
1225 | case DLM_MASTER_RESP_NO: | |
1226 | mlog(0, "node %u not master, response=NO\n", to); | |
1227 | set_bit(to, mle->response_map); | |
1228 | break; | |
1229 | case DLM_MASTER_RESP_MAYBE: | |
1230 | mlog(0, "node %u not master, response=MAYBE\n", to); | |
1231 | set_bit(to, mle->response_map); | |
1232 | set_bit(to, mle->maybe_map); | |
1233 | break; | |
1234 | case DLM_MASTER_RESP_ERROR: | |
1235 | mlog(0, "node %u hit an error, resending\n", to); | |
1236 | resend = 1; | |
1237 | response = 0; | |
1238 | break; | |
1239 | default: | |
1240 | mlog(ML_ERROR, "bad response! %u\n", response); | |
1241 | BUG(); | |
1242 | } | |
1243 | spin_unlock(&mle->spinlock); | |
1244 | if (resend) { | |
1245 | /* this is also totally crude */ | |
1246 | msleep(50); | |
1247 | goto again; | |
1248 | } | |
1249 | ||
1250 | out: | |
1251 | return ret; | |
1252 | } | |
1253 | ||
1254 | /* | |
1255 | * locks that can be taken here: | |
1256 | * dlm->spinlock | |
1257 | * res->spinlock | |
1258 | * mle->spinlock | |
1259 | * dlm->master_list | |
1260 | * | |
1261 | * if possible, TRIM THIS DOWN!!! | |
1262 | */ | |
1263 | int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data) | |
1264 | { | |
1265 | u8 response = DLM_MASTER_RESP_MAYBE; | |
1266 | struct dlm_ctxt *dlm = data; | |
9c6510a5 | 1267 | struct dlm_lock_resource *res = NULL; |
6714d8e8 KH |
1268 | struct dlm_master_request *request = (struct dlm_master_request *) msg->buf; |
1269 | struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL; | |
1270 | char *name; | |
1271 | unsigned int namelen; | |
1272 | int found, ret; | |
1273 | int set_maybe; | |
9c6510a5 | 1274 | int dispatch_assert = 0; |
6714d8e8 KH |
1275 | |
1276 | if (!dlm_grab(dlm)) | |
1277 | return DLM_MASTER_RESP_NO; | |
1278 | ||
1279 | if (!dlm_domain_fully_joined(dlm)) { | |
1280 | response = DLM_MASTER_RESP_NO; | |
1281 | goto send_response; | |
1282 | } | |
1283 | ||
1284 | name = request->name; | |
1285 | namelen = request->namelen; | |
1286 | ||
1287 | if (namelen > DLM_LOCKID_NAME_MAX) { | |
1288 | response = DLM_IVBUFLEN; | |
1289 | goto send_response; | |
1290 | } | |
1291 | ||
1292 | way_up_top: | |
1293 | spin_lock(&dlm->spinlock); | |
1294 | res = __dlm_lookup_lockres(dlm, name, namelen); | |
1295 | if (res) { | |
1296 | spin_unlock(&dlm->spinlock); | |
1297 | ||
1298 | /* take care of the easy cases up front */ | |
1299 | spin_lock(&res->spinlock); | |
1300 | if (res->state & DLM_LOCK_RES_RECOVERING) { | |
1301 | spin_unlock(&res->spinlock); | |
1302 | mlog(0, "returning DLM_MASTER_RESP_ERROR since res is " | |
1303 | "being recovered\n"); | |
1304 | response = DLM_MASTER_RESP_ERROR; | |
1305 | if (mle) | |
1306 | kmem_cache_free(dlm_mle_cache, mle); | |
1307 | goto send_response; | |
1308 | } | |
1309 | ||
1310 | if (res->owner == dlm->node_num) { | |
6714d8e8 KH |
1311 | spin_unlock(&res->spinlock); |
1312 | // mlog(0, "this node is the master\n"); | |
1313 | response = DLM_MASTER_RESP_YES; | |
1314 | if (mle) | |
1315 | kmem_cache_free(dlm_mle_cache, mle); | |
1316 | ||
1317 | /* this node is the owner. | |
1318 | * there is some extra work that needs to | |
1319 | * happen now. the requesting node has | |
1320 | * caused all nodes up to this one to | |
1321 | * create mles. this node now needs to | |
1322 | * go back and clean those up. */ | |
9c6510a5 | 1323 | dispatch_assert = 1; |
6714d8e8 KH |
1324 | goto send_response; |
1325 | } else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) { | |
1326 | spin_unlock(&res->spinlock); | |
1327 | // mlog(0, "node %u is the master\n", res->owner); | |
1328 | response = DLM_MASTER_RESP_NO; | |
1329 | if (mle) | |
1330 | kmem_cache_free(dlm_mle_cache, mle); | |
1331 | goto send_response; | |
1332 | } | |
1333 | ||
1334 | /* ok, there is no owner. either this node is | |
1335 | * being blocked, or it is actively trying to | |
1336 | * master this lock. */ | |
1337 | if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) { | |
1338 | mlog(ML_ERROR, "lock with no owner should be " | |
1339 | "in-progress!\n"); | |
1340 | BUG(); | |
1341 | } | |
1342 | ||
1343 | // mlog(0, "lockres is in progress...\n"); | |
1344 | spin_lock(&dlm->master_lock); | |
1345 | found = dlm_find_mle(dlm, &tmpmle, name, namelen); | |
1346 | if (!found) { | |
1347 | mlog(ML_ERROR, "no mle found for this lock!\n"); | |
1348 | BUG(); | |
1349 | } | |
1350 | set_maybe = 1; | |
1351 | spin_lock(&tmpmle->spinlock); | |
1352 | if (tmpmle->type == DLM_MLE_BLOCK) { | |
1353 | // mlog(0, "this node is waiting for " | |
1354 | // "lockres to be mastered\n"); | |
1355 | response = DLM_MASTER_RESP_NO; | |
1356 | } else if (tmpmle->type == DLM_MLE_MIGRATION) { | |
1357 | mlog(0, "node %u is master, but trying to migrate to " | |
1358 | "node %u.\n", tmpmle->master, tmpmle->new_master); | |
1359 | if (tmpmle->master == dlm->node_num) { | |
1360 | response = DLM_MASTER_RESP_YES; | |
1361 | mlog(ML_ERROR, "no owner on lockres, but this " | |
1362 | "node is trying to migrate it to %u?!\n", | |
1363 | tmpmle->new_master); | |
1364 | BUG(); | |
1365 | } else { | |
1366 | /* the real master can respond on its own */ | |
1367 | response = DLM_MASTER_RESP_NO; | |
1368 | } | |
1369 | } else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) { | |
1370 | set_maybe = 0; | |
9c6510a5 | 1371 | if (tmpmle->master == dlm->node_num) { |
6714d8e8 | 1372 | response = DLM_MASTER_RESP_YES; |
9c6510a5 KH |
1373 | /* this node will be the owner. |
1374 | * go back and clean the mles on any | |
1375 | * other nodes */ | |
1376 | dispatch_assert = 1; | |
1377 | } else | |
6714d8e8 KH |
1378 | response = DLM_MASTER_RESP_NO; |
1379 | } else { | |
1380 | // mlog(0, "this node is attempting to " | |
1381 | // "master lockres\n"); | |
1382 | response = DLM_MASTER_RESP_MAYBE; | |
1383 | } | |
1384 | if (set_maybe) | |
1385 | set_bit(request->node_idx, tmpmle->maybe_map); | |
1386 | spin_unlock(&tmpmle->spinlock); | |
1387 | ||
1388 | spin_unlock(&dlm->master_lock); | |
1389 | spin_unlock(&res->spinlock); | |
1390 | ||
1391 | /* keep the mle attached to heartbeat events */ | |
1392 | dlm_put_mle(tmpmle); | |
1393 | if (mle) | |
1394 | kmem_cache_free(dlm_mle_cache, mle); | |
1395 | goto send_response; | |
1396 | } | |
1397 | ||
1398 | /* | |
1399 | * lockres doesn't exist on this node | |
1400 | * if there is an MLE_BLOCK, return NO | |
1401 | * if there is an MLE_MASTER, return MAYBE | |
1402 | * otherwise, add an MLE_BLOCK, return NO | |
1403 | */ | |
1404 | spin_lock(&dlm->master_lock); | |
1405 | found = dlm_find_mle(dlm, &tmpmle, name, namelen); | |
1406 | if (!found) { | |
1407 | /* this lockid has never been seen on this node yet */ | |
1408 | // mlog(0, "no mle found\n"); | |
1409 | if (!mle) { | |
1410 | spin_unlock(&dlm->master_lock); | |
1411 | spin_unlock(&dlm->spinlock); | |
1412 | ||
1413 | mle = (struct dlm_master_list_entry *) | |
1414 | kmem_cache_alloc(dlm_mle_cache, GFP_KERNEL); | |
1415 | if (!mle) { | |
6714d8e8 | 1416 | response = DLM_MASTER_RESP_ERROR; |
9c6510a5 | 1417 | mlog_errno(-ENOMEM); |
6714d8e8 KH |
1418 | goto send_response; |
1419 | } | |
1420 | spin_lock(&dlm->spinlock); | |
1421 | dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, | |
1422 | name, namelen); | |
1423 | spin_unlock(&dlm->spinlock); | |
1424 | goto way_up_top; | |
1425 | } | |
1426 | ||
1427 | // mlog(0, "this is second time thru, already allocated, " | |
1428 | // "add the block.\n"); | |
1429 | set_bit(request->node_idx, mle->maybe_map); | |
1430 | list_add(&mle->list, &dlm->master_list); | |
1431 | response = DLM_MASTER_RESP_NO; | |
1432 | } else { | |
1433 | // mlog(0, "mle was found\n"); | |
1434 | set_maybe = 1; | |
1435 | spin_lock(&tmpmle->spinlock); | |
9c6510a5 KH |
1436 | if (tmpmle->master == dlm->node_num) { |
1437 | mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n"); | |
1438 | BUG(); | |
1439 | } | |
6714d8e8 KH |
1440 | if (tmpmle->type == DLM_MLE_BLOCK) |
1441 | response = DLM_MASTER_RESP_NO; | |
1442 | else if (tmpmle->type == DLM_MLE_MIGRATION) { | |
1443 | mlog(0, "migration mle was found (%u->%u)\n", | |
1444 | tmpmle->master, tmpmle->new_master); | |
6714d8e8 KH |
1445 | /* real master can respond on its own */ |
1446 | response = DLM_MASTER_RESP_NO; | |
9c6510a5 KH |
1447 | } else |
1448 | response = DLM_MASTER_RESP_MAYBE; | |
6714d8e8 KH |
1449 | if (set_maybe) |
1450 | set_bit(request->node_idx, tmpmle->maybe_map); | |
1451 | spin_unlock(&tmpmle->spinlock); | |
1452 | } | |
1453 | spin_unlock(&dlm->master_lock); | |
1454 | spin_unlock(&dlm->spinlock); | |
1455 | ||
1456 | if (found) { | |
1457 | /* keep the mle attached to heartbeat events */ | |
1458 | dlm_put_mle(tmpmle); | |
1459 | } | |
1460 | send_response: | |
9c6510a5 KH |
1461 | |
1462 | if (dispatch_assert) { | |
1463 | if (response != DLM_MASTER_RESP_YES) | |
1464 | mlog(ML_ERROR, "invalid response %d\n", response); | |
1465 | if (!res) { | |
1466 | mlog(ML_ERROR, "bad lockres while trying to assert!\n"); | |
1467 | BUG(); | |
1468 | } | |
1469 | mlog(0, "%u is the owner of %.*s, cleaning everyone else\n", | |
1470 | dlm->node_num, res->lockname.len, res->lockname.name); | |
1471 | ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx, | |
1472 | DLM_ASSERT_MASTER_MLE_CLEANUP); | |
1473 | if (ret < 0) { | |
1474 | mlog(ML_ERROR, "failed to dispatch assert master work\n"); | |
1475 | response = DLM_MASTER_RESP_ERROR; | |
1476 | } | |
1477 | } | |
1478 | ||
6714d8e8 KH |
1479 | dlm_put(dlm); |
1480 | return response; | |
1481 | } | |
1482 | ||
1483 | /* | |
1484 | * DLM_ASSERT_MASTER_MSG | |
1485 | */ | |
1486 | ||
1487 | ||
1488 | /* | |
1489 | * NOTE: this can be used for debugging | |
1490 | * can periodically run all locks owned by this node | |
1491 | * and re-assert across the cluster... | |
1492 | */ | |
1493 | static int dlm_do_assert_master(struct dlm_ctxt *dlm, const char *lockname, | |
1494 | unsigned int namelen, void *nodemap, | |
1495 | u32 flags) | |
1496 | { | |
1497 | struct dlm_assert_master assert; | |
1498 | int to, tmpret; | |
1499 | struct dlm_node_iter iter; | |
1500 | int ret = 0; | |
9c6510a5 | 1501 | int reassert; |
6714d8e8 KH |
1502 | |
1503 | BUG_ON(namelen > O2NM_MAX_NAME_LEN); | |
9c6510a5 KH |
1504 | again: |
1505 | reassert = 0; | |
6714d8e8 KH |
1506 | |
1507 | /* note that if this nodemap is empty, it returns 0 */ | |
1508 | dlm_node_iter_init(nodemap, &iter); | |
1509 | while ((to = dlm_node_iter_next(&iter)) >= 0) { | |
1510 | int r = 0; | |
1511 | mlog(0, "sending assert master to %d (%.*s)\n", to, | |
1512 | namelen, lockname); | |
1513 | memset(&assert, 0, sizeof(assert)); | |
1514 | assert.node_idx = dlm->node_num; | |
1515 | assert.namelen = namelen; | |
1516 | memcpy(assert.name, lockname, namelen); | |
1517 | assert.flags = cpu_to_be32(flags); | |
1518 | ||
1519 | tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key, | |
1520 | &assert, sizeof(assert), to, &r); | |
1521 | if (tmpret < 0) { | |
1522 | mlog(ML_ERROR, "assert_master returned %d!\n", tmpret); | |
1523 | if (!dlm_is_host_down(tmpret)) { | |
1524 | mlog(ML_ERROR, "unhandled error!\n"); | |
1525 | BUG(); | |
1526 | } | |
1527 | /* a node died. finish out the rest of the nodes. */ | |
1528 | mlog(ML_ERROR, "link to %d went down!\n", to); | |
1529 | /* any nonzero status return will do */ | |
1530 | ret = tmpret; | |
1531 | } else if (r < 0) { | |
1532 | /* ok, something horribly messed. kill thyself. */ | |
1533 | mlog(ML_ERROR,"during assert master of %.*s to %u, " | |
1534 | "got %d.\n", namelen, lockname, to, r); | |
1535 | dlm_dump_lock_resources(dlm); | |
1536 | BUG(); | |
9c6510a5 KH |
1537 | } else if (r == EAGAIN) { |
1538 | mlog(0, "%.*s: node %u create mles on other " | |
1539 | "nodes and requests a re-assert\n", | |
1540 | namelen, lockname, to); | |
1541 | reassert = 1; | |
6714d8e8 KH |
1542 | } |
1543 | } | |
1544 | ||
9c6510a5 KH |
1545 | if (reassert) |
1546 | goto again; | |
1547 | ||
6714d8e8 KH |
1548 | return ret; |
1549 | } | |
1550 | ||
1551 | /* | |
1552 | * locks that can be taken here: | |
1553 | * dlm->spinlock | |
1554 | * res->spinlock | |
1555 | * mle->spinlock | |
1556 | * dlm->master_list | |
1557 | * | |
1558 | * if possible, TRIM THIS DOWN!!! | |
1559 | */ | |
1560 | int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data) | |
1561 | { | |
1562 | struct dlm_ctxt *dlm = data; | |
1563 | struct dlm_master_list_entry *mle = NULL; | |
1564 | struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf; | |
1565 | struct dlm_lock_resource *res = NULL; | |
1566 | char *name; | |
1567 | unsigned int namelen; | |
1568 | u32 flags; | |
9c6510a5 KH |
1569 | int master_request = 0; |
1570 | int ret = 0; | |
6714d8e8 KH |
1571 | |
1572 | if (!dlm_grab(dlm)) | |
1573 | return 0; | |
1574 | ||
1575 | name = assert->name; | |
1576 | namelen = assert->namelen; | |
1577 | flags = be32_to_cpu(assert->flags); | |
1578 | ||
1579 | if (namelen > DLM_LOCKID_NAME_MAX) { | |
1580 | mlog(ML_ERROR, "Invalid name length!"); | |
1581 | goto done; | |
1582 | } | |
1583 | ||
1584 | spin_lock(&dlm->spinlock); | |
1585 | ||
1586 | if (flags) | |
1587 | mlog(0, "assert_master with flags: %u\n", flags); | |
1588 | ||
1589 | /* find the MLE */ | |
1590 | spin_lock(&dlm->master_lock); | |
1591 | if (!dlm_find_mle(dlm, &mle, name, namelen)) { | |
1592 | /* not an error, could be master just re-asserting */ | |
1593 | mlog(0, "just got an assert_master from %u, but no " | |
1594 | "MLE for it! (%.*s)\n", assert->node_idx, | |
1595 | namelen, name); | |
1596 | } else { | |
1597 | int bit = find_next_bit (mle->maybe_map, O2NM_MAX_NODES, 0); | |
1598 | if (bit >= O2NM_MAX_NODES) { | |
1599 | /* not necessarily an error, though less likely. | |
1600 | * could be master just re-asserting. */ | |
1601 | mlog(ML_ERROR, "no bits set in the maybe_map, but %u " | |
1602 | "is asserting! (%.*s)\n", assert->node_idx, | |
1603 | namelen, name); | |
1604 | } else if (bit != assert->node_idx) { | |
1605 | if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) { | |
1606 | mlog(0, "master %u was found, %u should " | |
1607 | "back off\n", assert->node_idx, bit); | |
1608 | } else { | |
1609 | /* with the fix for bug 569, a higher node | |
1610 | * number winning the mastery will respond | |
1611 | * YES to mastery requests, but this node | |
1612 | * had no way of knowing. let it pass. */ | |
1613 | mlog(ML_ERROR, "%u is the lowest node, " | |
1614 | "%u is asserting. (%.*s) %u must " | |
1615 | "have begun after %u won.\n", bit, | |
1616 | assert->node_idx, namelen, name, bit, | |
1617 | assert->node_idx); | |
1618 | } | |
1619 | } | |
1620 | } | |
1621 | spin_unlock(&dlm->master_lock); | |
1622 | ||
1623 | /* ok everything checks out with the MLE | |
1624 | * now check to see if there is a lockres */ | |
1625 | res = __dlm_lookup_lockres(dlm, name, namelen); | |
1626 | if (res) { | |
1627 | spin_lock(&res->spinlock); | |
1628 | if (res->state & DLM_LOCK_RES_RECOVERING) { | |
1629 | mlog(ML_ERROR, "%u asserting but %.*s is " | |
1630 | "RECOVERING!\n", assert->node_idx, namelen, name); | |
1631 | goto kill; | |
1632 | } | |
1633 | if (!mle) { | |
1634 | if (res->owner != assert->node_idx) { | |
1635 | mlog(ML_ERROR, "assert_master from " | |
1636 | "%u, but current owner is " | |
1637 | "%u! (%.*s)\n", | |
1638 | assert->node_idx, res->owner, | |
1639 | namelen, name); | |
1640 | goto kill; | |
1641 | } | |
1642 | } else if (mle->type != DLM_MLE_MIGRATION) { | |
1643 | if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) { | |
1644 | /* owner is just re-asserting */ | |
1645 | if (res->owner == assert->node_idx) { | |
1646 | mlog(0, "owner %u re-asserting on " | |
1647 | "lock %.*s\n", assert->node_idx, | |
1648 | namelen, name); | |
1649 | goto ok; | |
1650 | } | |
1651 | mlog(ML_ERROR, "got assert_master from " | |
1652 | "node %u, but %u is the owner! " | |
1653 | "(%.*s)\n", assert->node_idx, | |
1654 | res->owner, namelen, name); | |
1655 | goto kill; | |
1656 | } | |
1657 | if (!(res->state & DLM_LOCK_RES_IN_PROGRESS)) { | |
1658 | mlog(ML_ERROR, "got assert from %u, but lock " | |
1659 | "with no owner should be " | |
1660 | "in-progress! (%.*s)\n", | |
1661 | assert->node_idx, | |
1662 | namelen, name); | |
1663 | goto kill; | |
1664 | } | |
1665 | } else /* mle->type == DLM_MLE_MIGRATION */ { | |
1666 | /* should only be getting an assert from new master */ | |
1667 | if (assert->node_idx != mle->new_master) { | |
1668 | mlog(ML_ERROR, "got assert from %u, but " | |
1669 | "new master is %u, and old master " | |
1670 | "was %u (%.*s)\n", | |
1671 | assert->node_idx, mle->new_master, | |
1672 | mle->master, namelen, name); | |
1673 | goto kill; | |
1674 | } | |
1675 | ||
1676 | } | |
1677 | ok: | |
1678 | spin_unlock(&res->spinlock); | |
1679 | } | |
1680 | spin_unlock(&dlm->spinlock); | |
1681 | ||
1682 | // mlog(0, "woo! got an assert_master from node %u!\n", | |
1683 | // assert->node_idx); | |
1684 | if (mle) { | |
9c6510a5 KH |
1685 | int extra_ref = 0; |
1686 | int nn = -1; | |
6714d8e8 KH |
1687 | |
1688 | spin_lock(&mle->spinlock); | |
9c6510a5 KH |
1689 | if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION) |
1690 | extra_ref = 1; | |
1691 | else { | |
1692 | /* MASTER mle: if any bits set in the response map | |
1693 | * then the calling node needs to re-assert to clear | |
1694 | * up nodes that this node contacted */ | |
1695 | while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES, | |
1696 | nn+1)) < O2NM_MAX_NODES) { | |
1697 | if (nn != dlm->node_num && nn != assert->node_idx) | |
1698 | master_request = 1; | |
1699 | } | |
1700 | } | |
6714d8e8 KH |
1701 | mle->master = assert->node_idx; |
1702 | atomic_set(&mle->woken, 1); | |
1703 | wake_up(&mle->wq); | |
1704 | spin_unlock(&mle->spinlock); | |
1705 | ||
1706 | if (mle->type == DLM_MLE_MIGRATION && res) { | |
1707 | mlog(0, "finishing off migration of lockres %.*s, " | |
1708 | "from %u to %u\n", | |
1709 | res->lockname.len, res->lockname.name, | |
1710 | dlm->node_num, mle->new_master); | |
1711 | spin_lock(&res->spinlock); | |
1712 | res->state &= ~DLM_LOCK_RES_MIGRATING; | |
1713 | dlm_change_lockres_owner(dlm, res, mle->new_master); | |
1714 | BUG_ON(res->state & DLM_LOCK_RES_DIRTY); | |
1715 | spin_unlock(&res->spinlock); | |
1716 | } | |
1717 | /* master is known, detach if not already detached */ | |
1718 | dlm_mle_detach_hb_events(dlm, mle); | |
1719 | dlm_put_mle(mle); | |
1720 | ||
1721 | if (extra_ref) { | |
1722 | /* the assert master message now balances the extra | |
1723 | * ref given by the master / migration request message. | |
1724 | * if this is the last put, it will be removed | |
1725 | * from the list. */ | |
1726 | dlm_put_mle(mle); | |
1727 | } | |
1728 | } | |
1729 | ||
1730 | done: | |
9c6510a5 | 1731 | ret = 0; |
6714d8e8 KH |
1732 | if (res) |
1733 | dlm_lockres_put(res); | |
1734 | dlm_put(dlm); | |
9c6510a5 KH |
1735 | if (master_request) { |
1736 | mlog(0, "need to tell master to reassert\n"); | |
1737 | ret = EAGAIN; // positive. negative would shoot down the node. | |
1738 | } | |
1739 | return ret; | |
6714d8e8 KH |
1740 | |
1741 | kill: | |
1742 | /* kill the caller! */ | |
1743 | spin_unlock(&res->spinlock); | |
1744 | spin_unlock(&dlm->spinlock); | |
1745 | dlm_lockres_put(res); | |
1746 | mlog(ML_ERROR, "Bad message received from another node. Dumping state " | |
1747 | "and killing the other node now! This node is OK and can continue.\n"); | |
1748 | dlm_dump_lock_resources(dlm); | |
1749 | dlm_put(dlm); | |
1750 | return -EINVAL; | |
1751 | } | |
1752 | ||
1753 | int dlm_dispatch_assert_master(struct dlm_ctxt *dlm, | |
1754 | struct dlm_lock_resource *res, | |
1755 | int ignore_higher, u8 request_from, u32 flags) | |
1756 | { | |
1757 | struct dlm_work_item *item; | |
1758 | item = kcalloc(1, sizeof(*item), GFP_KERNEL); | |
1759 | if (!item) | |
1760 | return -ENOMEM; | |
1761 | ||
1762 | ||
1763 | /* queue up work for dlm_assert_master_worker */ | |
1764 | dlm_grab(dlm); /* get an extra ref for the work item */ | |
1765 | dlm_init_work_item(dlm, item, dlm_assert_master_worker, NULL); | |
1766 | item->u.am.lockres = res; /* already have a ref */ | |
1767 | /* can optionally ignore node numbers higher than this node */ | |
1768 | item->u.am.ignore_higher = ignore_higher; | |
1769 | item->u.am.request_from = request_from; | |
1770 | item->u.am.flags = flags; | |
1771 | ||
9c6510a5 KH |
1772 | if (ignore_higher) |
1773 | mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len, | |
1774 | res->lockname.name); | |
1775 | ||
6714d8e8 KH |
1776 | spin_lock(&dlm->work_lock); |
1777 | list_add_tail(&item->list, &dlm->work_list); | |
1778 | spin_unlock(&dlm->work_lock); | |
1779 | ||
1780 | schedule_work(&dlm->dispatched_work); | |
1781 | return 0; | |
1782 | } | |
1783 | ||
1784 | static void dlm_assert_master_worker(struct dlm_work_item *item, void *data) | |
1785 | { | |
1786 | struct dlm_ctxt *dlm = data; | |
1787 | int ret = 0; | |
1788 | struct dlm_lock_resource *res; | |
1789 | unsigned long nodemap[BITS_TO_LONGS(O2NM_MAX_NODES)]; | |
1790 | int ignore_higher; | |
1791 | int bit; | |
1792 | u8 request_from; | |
1793 | u32 flags; | |
1794 | ||
1795 | dlm = item->dlm; | |
1796 | res = item->u.am.lockres; | |
1797 | ignore_higher = item->u.am.ignore_higher; | |
1798 | request_from = item->u.am.request_from; | |
1799 | flags = item->u.am.flags; | |
1800 | ||
1801 | spin_lock(&dlm->spinlock); | |
1802 | memcpy(nodemap, dlm->domain_map, sizeof(nodemap)); | |
1803 | spin_unlock(&dlm->spinlock); | |
1804 | ||
1805 | clear_bit(dlm->node_num, nodemap); | |
1806 | if (ignore_higher) { | |
1807 | /* if is this just to clear up mles for nodes below | |
1808 | * this node, do not send the message to the original | |
1809 | * caller or any node number higher than this */ | |
1810 | clear_bit(request_from, nodemap); | |
1811 | bit = dlm->node_num; | |
1812 | while (1) { | |
1813 | bit = find_next_bit(nodemap, O2NM_MAX_NODES, | |
1814 | bit+1); | |
1815 | if (bit >= O2NM_MAX_NODES) | |
1816 | break; | |
1817 | clear_bit(bit, nodemap); | |
1818 | } | |
1819 | } | |
1820 | ||
1821 | /* this call now finishes out the nodemap | |
1822 | * even if one or more nodes die */ | |
1823 | mlog(0, "worker about to master %.*s here, this=%u\n", | |
1824 | res->lockname.len, res->lockname.name, dlm->node_num); | |
1825 | ret = dlm_do_assert_master(dlm, res->lockname.name, | |
1826 | res->lockname.len, | |
1827 | nodemap, flags); | |
1828 | if (ret < 0) { | |
1829 | /* no need to restart, we are done */ | |
1830 | mlog_errno(ret); | |
1831 | } | |
1832 | ||
1833 | dlm_lockres_put(res); | |
1834 | ||
1835 | mlog(0, "finished with dlm_assert_master_worker\n"); | |
1836 | } | |
1837 | ||
1838 | ||
1839 | /* | |
1840 | * DLM_MIGRATE_LOCKRES | |
1841 | */ | |
1842 | ||
1843 | ||
1844 | int dlm_migrate_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, | |
1845 | u8 target) | |
1846 | { | |
1847 | struct dlm_master_list_entry *mle = NULL; | |
1848 | struct dlm_master_list_entry *oldmle = NULL; | |
1849 | struct dlm_migratable_lockres *mres = NULL; | |
1850 | int ret = -EINVAL; | |
1851 | const char *name; | |
1852 | unsigned int namelen; | |
1853 | int mle_added = 0; | |
1854 | struct list_head *queue, *iter; | |
1855 | int i; | |
1856 | struct dlm_lock *lock; | |
1857 | int empty = 1; | |
1858 | ||
1859 | if (!dlm_grab(dlm)) | |
1860 | return -EINVAL; | |
1861 | ||
1862 | name = res->lockname.name; | |
1863 | namelen = res->lockname.len; | |
1864 | ||
1865 | mlog(0, "migrating %.*s to %u\n", namelen, name, target); | |
1866 | ||
1867 | /* | |
1868 | * ensure this lockres is a proper candidate for migration | |
1869 | */ | |
1870 | spin_lock(&res->spinlock); | |
1871 | if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) { | |
1872 | mlog(0, "cannot migrate lockres with unknown owner!\n"); | |
1873 | spin_unlock(&res->spinlock); | |
1874 | goto leave; | |
1875 | } | |
1876 | if (res->owner != dlm->node_num) { | |
1877 | mlog(0, "cannot migrate lockres this node doesn't own!\n"); | |
1878 | spin_unlock(&res->spinlock); | |
1879 | goto leave; | |
1880 | } | |
1881 | mlog(0, "checking queues...\n"); | |
1882 | queue = &res->granted; | |
1883 | for (i=0; i<3; i++) { | |
1884 | list_for_each(iter, queue) { | |
1885 | lock = list_entry (iter, struct dlm_lock, list); | |
1886 | empty = 0; | |
1887 | if (lock->ml.node == dlm->node_num) { | |
1888 | mlog(0, "found a lock owned by this node " | |
1889 | "still on the %s queue! will not " | |
1890 | "migrate this lockres\n", | |
1891 | i==0 ? "granted" : | |
1892 | (i==1 ? "converting" : "blocked")); | |
1893 | spin_unlock(&res->spinlock); | |
1894 | ret = -ENOTEMPTY; | |
1895 | goto leave; | |
1896 | } | |
1897 | } | |
1898 | queue++; | |
1899 | } | |
1900 | mlog(0, "all locks on this lockres are nonlocal. continuing\n"); | |
1901 | spin_unlock(&res->spinlock); | |
1902 | ||
1903 | /* no work to do */ | |
1904 | if (empty) { | |
1905 | mlog(0, "no locks were found on this lockres! done!\n"); | |
1906 | ret = 0; | |
1907 | goto leave; | |
1908 | } | |
1909 | ||
1910 | /* | |
1911 | * preallocate up front | |
1912 | * if this fails, abort | |
1913 | */ | |
1914 | ||
1915 | ret = -ENOMEM; | |
1916 | mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_KERNEL); | |
1917 | if (!mres) { | |
1918 | mlog_errno(ret); | |
1919 | goto leave; | |
1920 | } | |
1921 | ||
1922 | mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache, | |
1923 | GFP_KERNEL); | |
1924 | if (!mle) { | |
1925 | mlog_errno(ret); | |
1926 | goto leave; | |
1927 | } | |
1928 | ret = 0; | |
1929 | ||
1930 | /* | |
1931 | * find a node to migrate the lockres to | |
1932 | */ | |
1933 | ||
1934 | mlog(0, "picking a migration node\n"); | |
1935 | spin_lock(&dlm->spinlock); | |
1936 | /* pick a new node */ | |
1937 | if (!test_bit(target, dlm->domain_map) || | |
1938 | target >= O2NM_MAX_NODES) { | |
1939 | target = dlm_pick_migration_target(dlm, res); | |
1940 | } | |
1941 | mlog(0, "node %u chosen for migration\n", target); | |
1942 | ||
1943 | if (target >= O2NM_MAX_NODES || | |
1944 | !test_bit(target, dlm->domain_map)) { | |
1945 | /* target chosen is not alive */ | |
1946 | ret = -EINVAL; | |
1947 | } | |
1948 | ||
1949 | if (ret) { | |
1950 | spin_unlock(&dlm->spinlock); | |
1951 | goto fail; | |
1952 | } | |
1953 | ||
1954 | mlog(0, "continuing with target = %u\n", target); | |
1955 | ||
1956 | /* | |
1957 | * clear any existing master requests and | |
1958 | * add the migration mle to the list | |
1959 | */ | |
1960 | spin_lock(&dlm->master_lock); | |
1961 | ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, name, | |
1962 | namelen, target, dlm->node_num); | |
1963 | spin_unlock(&dlm->master_lock); | |
1964 | spin_unlock(&dlm->spinlock); | |
1965 | ||
1966 | if (ret == -EEXIST) { | |
1967 | mlog(0, "another process is already migrating it\n"); | |
1968 | goto fail; | |
1969 | } | |
1970 | mle_added = 1; | |
1971 | ||
1972 | /* | |
1973 | * set the MIGRATING flag and flush asts | |
1974 | * if we fail after this we need to re-dirty the lockres | |
1975 | */ | |
1976 | if (dlm_mark_lockres_migrating(dlm, res, target) < 0) { | |
1977 | mlog(ML_ERROR, "tried to migrate %.*s to %u, but " | |
1978 | "the target went down.\n", res->lockname.len, | |
1979 | res->lockname.name, target); | |
1980 | spin_lock(&res->spinlock); | |
1981 | res->state &= ~DLM_LOCK_RES_MIGRATING; | |
1982 | spin_unlock(&res->spinlock); | |
1983 | ret = -EINVAL; | |
1984 | } | |
1985 | ||
1986 | fail: | |
1987 | if (oldmle) { | |
1988 | /* master is known, detach if not already detached */ | |
1989 | dlm_mle_detach_hb_events(dlm, oldmle); | |
1990 | dlm_put_mle(oldmle); | |
1991 | } | |
1992 | ||
1993 | if (ret < 0) { | |
1994 | if (mle_added) { | |
1995 | dlm_mle_detach_hb_events(dlm, mle); | |
1996 | dlm_put_mle(mle); | |
1997 | } else if (mle) { | |
1998 | kmem_cache_free(dlm_mle_cache, mle); | |
1999 | } | |
2000 | goto leave; | |
2001 | } | |
2002 | ||
2003 | /* | |
2004 | * at this point, we have a migration target, an mle | |
2005 | * in the master list, and the MIGRATING flag set on | |
2006 | * the lockres | |
2007 | */ | |
2008 | ||
2009 | ||
2010 | /* get an extra reference on the mle. | |
2011 | * otherwise the assert_master from the new | |
2012 | * master will destroy this. | |
2013 | * also, make sure that all callers of dlm_get_mle | |
2014 | * take both dlm->spinlock and dlm->master_lock */ | |
2015 | spin_lock(&dlm->spinlock); | |
2016 | spin_lock(&dlm->master_lock); | |
2017 | dlm_get_mle(mle); | |
2018 | spin_unlock(&dlm->master_lock); | |
2019 | spin_unlock(&dlm->spinlock); | |
2020 | ||
2021 | /* notify new node and send all lock state */ | |
2022 | /* call send_one_lockres with migration flag. | |
2023 | * this serves as notice to the target node that a | |
2024 | * migration is starting. */ | |
2025 | ret = dlm_send_one_lockres(dlm, res, mres, target, | |
2026 | DLM_MRES_MIGRATION); | |
2027 | ||
2028 | if (ret < 0) { | |
2029 | mlog(0, "migration to node %u failed with %d\n", | |
2030 | target, ret); | |
2031 | /* migration failed, detach and clean up mle */ | |
2032 | dlm_mle_detach_hb_events(dlm, mle); | |
2033 | dlm_put_mle(mle); | |
2034 | dlm_put_mle(mle); | |
2035 | goto leave; | |
2036 | } | |
2037 | ||
2038 | /* at this point, the target sends a message to all nodes, | |
2039 | * (using dlm_do_migrate_request). this node is skipped since | |
2040 | * we had to put an mle in the list to begin the process. this | |
2041 | * node now waits for target to do an assert master. this node | |
2042 | * will be the last one notified, ensuring that the migration | |
2043 | * is complete everywhere. if the target dies while this is | |
2044 | * going on, some nodes could potentially see the target as the | |
2045 | * master, so it is important that my recovery finds the migration | |
2046 | * mle and sets the master to UNKNONWN. */ | |
2047 | ||
2048 | ||
2049 | /* wait for new node to assert master */ | |
2050 | while (1) { | |
2051 | ret = wait_event_interruptible_timeout(mle->wq, | |
2052 | (atomic_read(&mle->woken) == 1), | |
2053 | msecs_to_jiffies(5000)); | |
2054 | ||
2055 | if (ret >= 0) { | |
2056 | if (atomic_read(&mle->woken) == 1 || | |
2057 | res->owner == target) | |
2058 | break; | |
2059 | ||
2060 | mlog(0, "timed out during migration\n"); | |
e2faea4c KH |
2061 | /* avoid hang during shutdown when migrating lockres |
2062 | * to a node which also goes down */ | |
2063 | if (dlm_is_node_dead(dlm, target)) { | |
2064 | mlog(0, "%s:%.*s: expected migration target %u " | |
2065 | "is no longer up. restarting.\n", | |
2066 | dlm->name, res->lockname.len, | |
2067 | res->lockname.name, target); | |
2068 | ret = -ERESTARTSYS; | |
2069 | } | |
6714d8e8 KH |
2070 | } |
2071 | if (ret == -ERESTARTSYS) { | |
2072 | /* migration failed, detach and clean up mle */ | |
2073 | dlm_mle_detach_hb_events(dlm, mle); | |
2074 | dlm_put_mle(mle); | |
2075 | dlm_put_mle(mle); | |
2076 | goto leave; | |
2077 | } | |
2078 | /* TODO: if node died: stop, clean up, return error */ | |
2079 | } | |
2080 | ||
2081 | /* all done, set the owner, clear the flag */ | |
2082 | spin_lock(&res->spinlock); | |
2083 | dlm_set_lockres_owner(dlm, res, target); | |
2084 | res->state &= ~DLM_LOCK_RES_MIGRATING; | |
2085 | dlm_remove_nonlocal_locks(dlm, res); | |
2086 | spin_unlock(&res->spinlock); | |
2087 | wake_up(&res->wq); | |
2088 | ||
2089 | /* master is known, detach if not already detached */ | |
2090 | dlm_mle_detach_hb_events(dlm, mle); | |
2091 | dlm_put_mle(mle); | |
2092 | ret = 0; | |
2093 | ||
2094 | dlm_lockres_calc_usage(dlm, res); | |
2095 | ||
2096 | leave: | |
2097 | /* re-dirty the lockres if we failed */ | |
2098 | if (ret < 0) | |
2099 | dlm_kick_thread(dlm, res); | |
2100 | ||
2101 | /* TODO: cleanup */ | |
2102 | if (mres) | |
2103 | free_page((unsigned long)mres); | |
2104 | ||
2105 | dlm_put(dlm); | |
2106 | ||
2107 | mlog(0, "returning %d\n", ret); | |
2108 | return ret; | |
2109 | } | |
2110 | EXPORT_SYMBOL_GPL(dlm_migrate_lockres); | |
2111 | ||
2112 | int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock) | |
2113 | { | |
2114 | int ret; | |
2115 | spin_lock(&dlm->ast_lock); | |
2116 | spin_lock(&lock->spinlock); | |
2117 | ret = (list_empty(&lock->bast_list) && !lock->bast_pending); | |
2118 | spin_unlock(&lock->spinlock); | |
2119 | spin_unlock(&dlm->ast_lock); | |
2120 | return ret; | |
2121 | } | |
2122 | ||
2123 | static int dlm_migration_can_proceed(struct dlm_ctxt *dlm, | |
2124 | struct dlm_lock_resource *res, | |
2125 | u8 mig_target) | |
2126 | { | |
2127 | int can_proceed; | |
2128 | spin_lock(&res->spinlock); | |
2129 | can_proceed = !!(res->state & DLM_LOCK_RES_MIGRATING); | |
2130 | spin_unlock(&res->spinlock); | |
2131 | ||
2132 | /* target has died, so make the caller break out of the | |
2133 | * wait_event, but caller must recheck the domain_map */ | |
2134 | spin_lock(&dlm->spinlock); | |
2135 | if (!test_bit(mig_target, dlm->domain_map)) | |
2136 | can_proceed = 1; | |
2137 | spin_unlock(&dlm->spinlock); | |
2138 | return can_proceed; | |
2139 | } | |
2140 | ||
2141 | int dlm_lockres_is_dirty(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) | |
2142 | { | |
2143 | int ret; | |
2144 | spin_lock(&res->spinlock); | |
2145 | ret = !!(res->state & DLM_LOCK_RES_DIRTY); | |
2146 | spin_unlock(&res->spinlock); | |
2147 | return ret; | |
2148 | } | |
2149 | ||
2150 | ||
2151 | static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm, | |
2152 | struct dlm_lock_resource *res, | |
2153 | u8 target) | |
2154 | { | |
2155 | int ret = 0; | |
2156 | ||
2157 | mlog(0, "dlm_mark_lockres_migrating: %.*s, from %u to %u\n", | |
2158 | res->lockname.len, res->lockname.name, dlm->node_num, | |
2159 | target); | |
2160 | /* need to set MIGRATING flag on lockres. this is done by | |
2161 | * ensuring that all asts have been flushed for this lockres. */ | |
2162 | spin_lock(&res->spinlock); | |
2163 | BUG_ON(res->migration_pending); | |
2164 | res->migration_pending = 1; | |
2165 | /* strategy is to reserve an extra ast then release | |
2166 | * it below, letting the release do all of the work */ | |
2167 | __dlm_lockres_reserve_ast(res); | |
2168 | spin_unlock(&res->spinlock); | |
2169 | ||
2170 | /* now flush all the pending asts.. hang out for a bit */ | |
2171 | dlm_kick_thread(dlm, res); | |
2172 | wait_event(dlm->ast_wq, !dlm_lockres_is_dirty(dlm, res)); | |
2173 | dlm_lockres_release_ast(dlm, res); | |
2174 | ||
2175 | mlog(0, "about to wait on migration_wq, dirty=%s\n", | |
2176 | res->state & DLM_LOCK_RES_DIRTY ? "yes" : "no"); | |
2177 | /* if the extra ref we just put was the final one, this | |
2178 | * will pass thru immediately. otherwise, we need to wait | |
2179 | * for the last ast to finish. */ | |
2180 | again: | |
2181 | ret = wait_event_interruptible_timeout(dlm->migration_wq, | |
2182 | dlm_migration_can_proceed(dlm, res, target), | |
2183 | msecs_to_jiffies(1000)); | |
2184 | if (ret < 0) { | |
2185 | mlog(0, "woken again: migrating? %s, dead? %s\n", | |
2186 | res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no", | |
2187 | test_bit(target, dlm->domain_map) ? "no":"yes"); | |
2188 | } else { | |
2189 | mlog(0, "all is well: migrating? %s, dead? %s\n", | |
2190 | res->state & DLM_LOCK_RES_MIGRATING ? "yes":"no", | |
2191 | test_bit(target, dlm->domain_map) ? "no":"yes"); | |
2192 | } | |
2193 | if (!dlm_migration_can_proceed(dlm, res, target)) { | |
2194 | mlog(0, "trying again...\n"); | |
2195 | goto again; | |
2196 | } | |
2197 | ||
2198 | /* did the target go down or die? */ | |
2199 | spin_lock(&dlm->spinlock); | |
2200 | if (!test_bit(target, dlm->domain_map)) { | |
2201 | mlog(ML_ERROR, "aha. migration target %u just went down\n", | |
2202 | target); | |
2203 | ret = -EHOSTDOWN; | |
2204 | } | |
2205 | spin_unlock(&dlm->spinlock); | |
2206 | ||
2207 | /* | |
2208 | * at this point: | |
2209 | * | |
2210 | * o the DLM_LOCK_RES_MIGRATING flag is set | |
2211 | * o there are no pending asts on this lockres | |
2212 | * o all processes trying to reserve an ast on this | |
2213 | * lockres must wait for the MIGRATING flag to clear | |
2214 | */ | |
2215 | return ret; | |
2216 | } | |
2217 | ||
2218 | /* last step in the migration process. | |
2219 | * original master calls this to free all of the dlm_lock | |
2220 | * structures that used to be for other nodes. */ | |
2221 | static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm, | |
2222 | struct dlm_lock_resource *res) | |
2223 | { | |
2224 | struct list_head *iter, *iter2; | |
2225 | struct list_head *queue = &res->granted; | |
2226 | int i; | |
2227 | struct dlm_lock *lock; | |
2228 | ||
2229 | assert_spin_locked(&res->spinlock); | |
2230 | ||
2231 | BUG_ON(res->owner == dlm->node_num); | |
2232 | ||
2233 | for (i=0; i<3; i++) { | |
2234 | list_for_each_safe(iter, iter2, queue) { | |
2235 | lock = list_entry (iter, struct dlm_lock, list); | |
2236 | if (lock->ml.node != dlm->node_num) { | |
2237 | mlog(0, "putting lock for node %u\n", | |
2238 | lock->ml.node); | |
2239 | /* be extra careful */ | |
2240 | BUG_ON(!list_empty(&lock->ast_list)); | |
2241 | BUG_ON(!list_empty(&lock->bast_list)); | |
2242 | BUG_ON(lock->ast_pending); | |
2243 | BUG_ON(lock->bast_pending); | |
2244 | list_del_init(&lock->list); | |
2245 | dlm_lock_put(lock); | |
2246 | } | |
2247 | } | |
2248 | queue++; | |
2249 | } | |
2250 | } | |
2251 | ||
2252 | /* for now this is not too intelligent. we will | |
2253 | * need stats to make this do the right thing. | |
2254 | * this just finds the first lock on one of the | |
2255 | * queues and uses that node as the target. */ | |
2256 | static u8 dlm_pick_migration_target(struct dlm_ctxt *dlm, | |
2257 | struct dlm_lock_resource *res) | |
2258 | { | |
2259 | int i; | |
2260 | struct list_head *queue = &res->granted; | |
2261 | struct list_head *iter; | |
2262 | struct dlm_lock *lock; | |
2263 | int nodenum; | |
2264 | ||
2265 | assert_spin_locked(&dlm->spinlock); | |
2266 | ||
2267 | spin_lock(&res->spinlock); | |
2268 | for (i=0; i<3; i++) { | |
2269 | list_for_each(iter, queue) { | |
2270 | /* up to the caller to make sure this node | |
2271 | * is alive */ | |
2272 | lock = list_entry (iter, struct dlm_lock, list); | |
2273 | if (lock->ml.node != dlm->node_num) { | |
2274 | spin_unlock(&res->spinlock); | |
2275 | return lock->ml.node; | |
2276 | } | |
2277 | } | |
2278 | queue++; | |
2279 | } | |
2280 | spin_unlock(&res->spinlock); | |
2281 | mlog(0, "have not found a suitable target yet! checking domain map\n"); | |
2282 | ||
2283 | /* ok now we're getting desperate. pick anyone alive. */ | |
2284 | nodenum = -1; | |
2285 | while (1) { | |
2286 | nodenum = find_next_bit(dlm->domain_map, | |
2287 | O2NM_MAX_NODES, nodenum+1); | |
2288 | mlog(0, "found %d in domain map\n", nodenum); | |
2289 | if (nodenum >= O2NM_MAX_NODES) | |
2290 | break; | |
2291 | if (nodenum != dlm->node_num) { | |
2292 | mlog(0, "picking %d\n", nodenum); | |
2293 | return nodenum; | |
2294 | } | |
2295 | } | |
2296 | ||
2297 | mlog(0, "giving up. no master to migrate to\n"); | |
2298 | return DLM_LOCK_RES_OWNER_UNKNOWN; | |
2299 | } | |
2300 | ||
2301 | ||
2302 | ||
2303 | /* this is called by the new master once all lockres | |
2304 | * data has been received */ | |
2305 | static int dlm_do_migrate_request(struct dlm_ctxt *dlm, | |
2306 | struct dlm_lock_resource *res, | |
2307 | u8 master, u8 new_master, | |
2308 | struct dlm_node_iter *iter) | |
2309 | { | |
2310 | struct dlm_migrate_request migrate; | |
2311 | int ret, status = 0; | |
2312 | int nodenum; | |
2313 | ||
2314 | memset(&migrate, 0, sizeof(migrate)); | |
2315 | migrate.namelen = res->lockname.len; | |
2316 | memcpy(migrate.name, res->lockname.name, migrate.namelen); | |
2317 | migrate.new_master = new_master; | |
2318 | migrate.master = master; | |
2319 | ||
2320 | ret = 0; | |
2321 | ||
2322 | /* send message to all nodes, except the master and myself */ | |
2323 | while ((nodenum = dlm_node_iter_next(iter)) >= 0) { | |
2324 | if (nodenum == master || | |
2325 | nodenum == new_master) | |
2326 | continue; | |
2327 | ||
2328 | ret = o2net_send_message(DLM_MIGRATE_REQUEST_MSG, dlm->key, | |
2329 | &migrate, sizeof(migrate), nodenum, | |
2330 | &status); | |
2331 | if (ret < 0) | |
2332 | mlog_errno(ret); | |
2333 | else if (status < 0) { | |
2334 | mlog(0, "migrate request (node %u) returned %d!\n", | |
2335 | nodenum, status); | |
2336 | ret = status; | |
2337 | } | |
2338 | } | |
2339 | ||
2340 | if (ret < 0) | |
2341 | mlog_errno(ret); | |
2342 | ||
2343 | mlog(0, "returning ret=%d\n", ret); | |
2344 | return ret; | |
2345 | } | |
2346 | ||
2347 | ||
2348 | /* if there is an existing mle for this lockres, we now know who the master is. | |
2349 | * (the one who sent us *this* message) we can clear it up right away. | |
2350 | * since the process that put the mle on the list still has a reference to it, | |
2351 | * we can unhash it now, set the master and wake the process. as a result, | |
2352 | * we will have no mle in the list to start with. now we can add an mle for | |
2353 | * the migration and this should be the only one found for those scanning the | |
2354 | * list. */ | |
2355 | int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data) | |
2356 | { | |
2357 | struct dlm_ctxt *dlm = data; | |
2358 | struct dlm_lock_resource *res = NULL; | |
2359 | struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf; | |
2360 | struct dlm_master_list_entry *mle = NULL, *oldmle = NULL; | |
2361 | const char *name; | |
2362 | unsigned int namelen; | |
2363 | int ret = 0; | |
2364 | ||
2365 | if (!dlm_grab(dlm)) | |
2366 | return -EINVAL; | |
2367 | ||
2368 | name = migrate->name; | |
2369 | namelen = migrate->namelen; | |
2370 | ||
2371 | /* preallocate.. if this fails, abort */ | |
2372 | mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache, | |
2373 | GFP_KERNEL); | |
2374 | ||
2375 | if (!mle) { | |
2376 | ret = -ENOMEM; | |
2377 | goto leave; | |
2378 | } | |
2379 | ||
2380 | /* check for pre-existing lock */ | |
2381 | spin_lock(&dlm->spinlock); | |
2382 | res = __dlm_lookup_lockres(dlm, name, namelen); | |
2383 | spin_lock(&dlm->master_lock); | |
2384 | ||
2385 | if (res) { | |
2386 | spin_lock(&res->spinlock); | |
2387 | if (res->state & DLM_LOCK_RES_RECOVERING) { | |
2388 | /* if all is working ok, this can only mean that we got | |
2389 | * a migrate request from a node that we now see as | |
2390 | * dead. what can we do here? drop it to the floor? */ | |
2391 | spin_unlock(&res->spinlock); | |
2392 | mlog(ML_ERROR, "Got a migrate request, but the " | |
2393 | "lockres is marked as recovering!"); | |
2394 | kmem_cache_free(dlm_mle_cache, mle); | |
2395 | ret = -EINVAL; /* need a better solution */ | |
2396 | goto unlock; | |
2397 | } | |
2398 | res->state |= DLM_LOCK_RES_MIGRATING; | |
2399 | spin_unlock(&res->spinlock); | |
2400 | } | |
2401 | ||
2402 | /* ignore status. only nonzero status would BUG. */ | |
2403 | ret = dlm_add_migration_mle(dlm, res, mle, &oldmle, | |
2404 | name, namelen, | |
2405 | migrate->new_master, | |
2406 | migrate->master); | |
2407 | ||
2408 | unlock: | |
2409 | spin_unlock(&dlm->master_lock); | |
2410 | spin_unlock(&dlm->spinlock); | |
2411 | ||
2412 | if (oldmle) { | |
2413 | /* master is known, detach if not already detached */ | |
2414 | dlm_mle_detach_hb_events(dlm, oldmle); | |
2415 | dlm_put_mle(oldmle); | |
2416 | } | |
2417 | ||
2418 | if (res) | |
2419 | dlm_lockres_put(res); | |
2420 | leave: | |
2421 | dlm_put(dlm); | |
2422 | return ret; | |
2423 | } | |
2424 | ||
2425 | /* must be holding dlm->spinlock and dlm->master_lock | |
2426 | * when adding a migration mle, we can clear any other mles | |
2427 | * in the master list because we know with certainty that | |
2428 | * the master is "master". so we remove any old mle from | |
2429 | * the list after setting it's master field, and then add | |
2430 | * the new migration mle. this way we can hold with the rule | |
2431 | * of having only one mle for a given lock name at all times. */ | |
2432 | static int dlm_add_migration_mle(struct dlm_ctxt *dlm, | |
2433 | struct dlm_lock_resource *res, | |
2434 | struct dlm_master_list_entry *mle, | |
2435 | struct dlm_master_list_entry **oldmle, | |
2436 | const char *name, unsigned int namelen, | |
2437 | u8 new_master, u8 master) | |
2438 | { | |
2439 | int found; | |
2440 | int ret = 0; | |
2441 | ||
2442 | *oldmle = NULL; | |
2443 | ||
2444 | mlog_entry_void(); | |
2445 | ||
2446 | assert_spin_locked(&dlm->spinlock); | |
2447 | assert_spin_locked(&dlm->master_lock); | |
2448 | ||
2449 | /* caller is responsible for any ref taken here on oldmle */ | |
2450 | found = dlm_find_mle(dlm, oldmle, (char *)name, namelen); | |
2451 | if (found) { | |
2452 | struct dlm_master_list_entry *tmp = *oldmle; | |
2453 | spin_lock(&tmp->spinlock); | |
2454 | if (tmp->type == DLM_MLE_MIGRATION) { | |
2455 | if (master == dlm->node_num) { | |
2456 | /* ah another process raced me to it */ | |
2457 | mlog(0, "tried to migrate %.*s, but some " | |
2458 | "process beat me to it\n", | |
2459 | namelen, name); | |
2460 | ret = -EEXIST; | |
2461 | } else { | |
2462 | /* bad. 2 NODES are trying to migrate! */ | |
2463 | mlog(ML_ERROR, "migration error mle: " | |
2464 | "master=%u new_master=%u // request: " | |
2465 | "master=%u new_master=%u // " | |
2466 | "lockres=%.*s\n", | |
2467 | tmp->master, tmp->new_master, | |
2468 | master, new_master, | |
2469 | namelen, name); | |
2470 | BUG(); | |
2471 | } | |
2472 | } else { | |
2473 | /* this is essentially what assert_master does */ | |
2474 | tmp->master = master; | |
2475 | atomic_set(&tmp->woken, 1); | |
2476 | wake_up(&tmp->wq); | |
2477 | /* remove it from the list so that only one | |
2478 | * mle will be found */ | |
2479 | list_del_init(&tmp->list); | |
2480 | } | |
2481 | spin_unlock(&tmp->spinlock); | |
2482 | } | |
2483 | ||
2484 | /* now add a migration mle to the tail of the list */ | |
2485 | dlm_init_mle(mle, DLM_MLE_MIGRATION, dlm, res, name, namelen); | |
2486 | mle->new_master = new_master; | |
2487 | mle->master = master; | |
2488 | /* do this for consistency with other mle types */ | |
2489 | set_bit(new_master, mle->maybe_map); | |
2490 | list_add(&mle->list, &dlm->master_list); | |
2491 | ||
2492 | return ret; | |
2493 | } | |
2494 | ||
2495 | ||
2496 | void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node) | |
2497 | { | |
2498 | struct list_head *iter, *iter2; | |
2499 | struct dlm_master_list_entry *mle; | |
2500 | struct dlm_lock_resource *res; | |
2501 | ||
2502 | mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node); | |
2503 | top: | |
2504 | assert_spin_locked(&dlm->spinlock); | |
2505 | ||
2506 | /* clean the master list */ | |
2507 | spin_lock(&dlm->master_lock); | |
2508 | list_for_each_safe(iter, iter2, &dlm->master_list) { | |
2509 | mle = list_entry(iter, struct dlm_master_list_entry, list); | |
2510 | ||
2511 | BUG_ON(mle->type != DLM_MLE_BLOCK && | |
2512 | mle->type != DLM_MLE_MASTER && | |
2513 | mle->type != DLM_MLE_MIGRATION); | |
2514 | ||
2515 | /* MASTER mles are initiated locally. the waiting | |
2516 | * process will notice the node map change | |
2517 | * shortly. let that happen as normal. */ | |
2518 | if (mle->type == DLM_MLE_MASTER) | |
2519 | continue; | |
2520 | ||
2521 | ||
2522 | /* BLOCK mles are initiated by other nodes. | |
2523 | * need to clean up if the dead node would have | |
2524 | * been the master. */ | |
2525 | if (mle->type == DLM_MLE_BLOCK) { | |
2526 | int bit; | |
2527 | ||
2528 | spin_lock(&mle->spinlock); | |
2529 | bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0); | |
2530 | if (bit != dead_node) { | |
2531 | mlog(0, "mle found, but dead node %u would " | |
2532 | "not have been master\n", dead_node); | |
2533 | spin_unlock(&mle->spinlock); | |
2534 | } else { | |
2535 | /* must drop the refcount by one since the | |
2536 | * assert_master will never arrive. this | |
2537 | * may result in the mle being unlinked and | |
2538 | * freed, but there may still be a process | |
2539 | * waiting in the dlmlock path which is fine. */ | |
2540 | mlog(ML_ERROR, "node %u was expected master\n", | |
2541 | dead_node); | |
2542 | atomic_set(&mle->woken, 1); | |
2543 | spin_unlock(&mle->spinlock); | |
2544 | wake_up(&mle->wq); | |
f671c09b KH |
2545 | /* do not need events any longer, so detach |
2546 | * from heartbeat */ | |
2547 | __dlm_mle_detach_hb_events(dlm, mle); | |
6714d8e8 KH |
2548 | __dlm_put_mle(mle); |
2549 | } | |
2550 | continue; | |
2551 | } | |
2552 | ||
2553 | /* everything else is a MIGRATION mle */ | |
2554 | ||
2555 | /* the rule for MIGRATION mles is that the master | |
2556 | * becomes UNKNOWN if *either* the original or | |
2557 | * the new master dies. all UNKNOWN lockreses | |
2558 | * are sent to whichever node becomes the recovery | |
2559 | * master. the new master is responsible for | |
2560 | * determining if there is still a master for | |
2561 | * this lockres, or if he needs to take over | |
2562 | * mastery. either way, this node should expect | |
2563 | * another message to resolve this. */ | |
2564 | if (mle->master != dead_node && | |
2565 | mle->new_master != dead_node) | |
2566 | continue; | |
2567 | ||
2568 | /* if we have reached this point, this mle needs to | |
2569 | * be removed from the list and freed. */ | |
2570 | ||
2571 | /* remove from the list early. NOTE: unlinking | |
2572 | * list_head while in list_for_each_safe */ | |
2573 | spin_lock(&mle->spinlock); | |
2574 | list_del_init(&mle->list); | |
2575 | atomic_set(&mle->woken, 1); | |
2576 | spin_unlock(&mle->spinlock); | |
2577 | wake_up(&mle->wq); | |
2578 | ||
2579 | mlog(0, "node %u died during migration from " | |
2580 | "%u to %u!\n", dead_node, | |
2581 | mle->master, mle->new_master); | |
2582 | /* if there is a lockres associated with this | |
2583 | * mle, find it and set its owner to UNKNOWN */ | |
2584 | res = __dlm_lookup_lockres(dlm, mle->u.name.name, | |
2585 | mle->u.name.len); | |
2586 | if (res) { | |
2587 | /* unfortunately if we hit this rare case, our | |
2588 | * lock ordering is messed. we need to drop | |
2589 | * the master lock so that we can take the | |
2590 | * lockres lock, meaning that we will have to | |
2591 | * restart from the head of list. */ | |
2592 | spin_unlock(&dlm->master_lock); | |
2593 | ||
2594 | /* move lockres onto recovery list */ | |
2595 | spin_lock(&res->spinlock); | |
2596 | dlm_set_lockres_owner(dlm, res, | |
2597 | DLM_LOCK_RES_OWNER_UNKNOWN); | |
2598 | dlm_move_lockres_to_recovery_list(dlm, res); | |
2599 | spin_unlock(&res->spinlock); | |
2600 | dlm_lockres_put(res); | |
2601 | ||
f671c09b KH |
2602 | /* about to get rid of mle, detach from heartbeat */ |
2603 | __dlm_mle_detach_hb_events(dlm, mle); | |
2604 | ||
6714d8e8 KH |
2605 | /* dump the mle */ |
2606 | spin_lock(&dlm->master_lock); | |
2607 | __dlm_put_mle(mle); | |
2608 | spin_unlock(&dlm->master_lock); | |
2609 | ||
2610 | /* restart */ | |
2611 | goto top; | |
2612 | } | |
2613 | ||
2614 | /* this may be the last reference */ | |
2615 | __dlm_put_mle(mle); | |
2616 | } | |
2617 | spin_unlock(&dlm->master_lock); | |
2618 | } | |
2619 | ||
2620 | ||
2621 | int dlm_finish_migration(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, | |
2622 | u8 old_master) | |
2623 | { | |
2624 | struct dlm_node_iter iter; | |
2625 | int ret = 0; | |
2626 | ||
2627 | spin_lock(&dlm->spinlock); | |
2628 | dlm_node_iter_init(dlm->domain_map, &iter); | |
2629 | clear_bit(old_master, iter.node_map); | |
2630 | clear_bit(dlm->node_num, iter.node_map); | |
2631 | spin_unlock(&dlm->spinlock); | |
2632 | ||
2633 | mlog(0, "now time to do a migrate request to other nodes\n"); | |
2634 | ret = dlm_do_migrate_request(dlm, res, old_master, | |
2635 | dlm->node_num, &iter); | |
2636 | if (ret < 0) { | |
2637 | mlog_errno(ret); | |
2638 | goto leave; | |
2639 | } | |
2640 | ||
2641 | mlog(0, "doing assert master of %.*s to all except the original node\n", | |
2642 | res->lockname.len, res->lockname.name); | |
2643 | /* this call now finishes out the nodemap | |
2644 | * even if one or more nodes die */ | |
2645 | ret = dlm_do_assert_master(dlm, res->lockname.name, | |
2646 | res->lockname.len, iter.node_map, | |
2647 | DLM_ASSERT_MASTER_FINISH_MIGRATION); | |
2648 | if (ret < 0) { | |
2649 | /* no longer need to retry. all living nodes contacted. */ | |
2650 | mlog_errno(ret); | |
2651 | ret = 0; | |
2652 | } | |
2653 | ||
2654 | memset(iter.node_map, 0, sizeof(iter.node_map)); | |
2655 | set_bit(old_master, iter.node_map); | |
2656 | mlog(0, "doing assert master of %.*s back to %u\n", | |
2657 | res->lockname.len, res->lockname.name, old_master); | |
2658 | ret = dlm_do_assert_master(dlm, res->lockname.name, | |
2659 | res->lockname.len, iter.node_map, | |
2660 | DLM_ASSERT_MASTER_FINISH_MIGRATION); | |
2661 | if (ret < 0) { | |
2662 | mlog(0, "assert master to original master failed " | |
2663 | "with %d.\n", ret); | |
2664 | /* the only nonzero status here would be because of | |
2665 | * a dead original node. we're done. */ | |
2666 | ret = 0; | |
2667 | } | |
2668 | ||
2669 | /* all done, set the owner, clear the flag */ | |
2670 | spin_lock(&res->spinlock); | |
2671 | dlm_set_lockres_owner(dlm, res, dlm->node_num); | |
2672 | res->state &= ~DLM_LOCK_RES_MIGRATING; | |
2673 | spin_unlock(&res->spinlock); | |
2674 | /* re-dirty it on the new master */ | |
2675 | dlm_kick_thread(dlm, res); | |
2676 | wake_up(&res->wq); | |
2677 | leave: | |
2678 | return ret; | |
2679 | } | |
2680 | ||
2681 | /* | |
2682 | * LOCKRES AST REFCOUNT | |
2683 | * this is integral to migration | |
2684 | */ | |
2685 | ||
2686 | /* for future intent to call an ast, reserve one ahead of time. | |
2687 | * this should be called only after waiting on the lockres | |
2688 | * with dlm_wait_on_lockres, and while still holding the | |
2689 | * spinlock after the call. */ | |
2690 | void __dlm_lockres_reserve_ast(struct dlm_lock_resource *res) | |
2691 | { | |
2692 | assert_spin_locked(&res->spinlock); | |
2693 | if (res->state & DLM_LOCK_RES_MIGRATING) { | |
2694 | __dlm_print_one_lock_resource(res); | |
2695 | } | |
2696 | BUG_ON(res->state & DLM_LOCK_RES_MIGRATING); | |
2697 | ||
2698 | atomic_inc(&res->asts_reserved); | |
2699 | } | |
2700 | ||
2701 | /* | |
2702 | * used to drop the reserved ast, either because it went unused, | |
2703 | * or because the ast/bast was actually called. | |
2704 | * | |
2705 | * also, if there is a pending migration on this lockres, | |
2706 | * and this was the last pending ast on the lockres, | |
2707 | * atomically set the MIGRATING flag before we drop the lock. | |
2708 | * this is how we ensure that migration can proceed with no | |
2709 | * asts in progress. note that it is ok if the state of the | |
2710 | * queues is such that a lock should be granted in the future | |
2711 | * or that a bast should be fired, because the new master will | |
2712 | * shuffle the lists on this lockres as soon as it is migrated. | |
2713 | */ | |
2714 | void dlm_lockres_release_ast(struct dlm_ctxt *dlm, | |
2715 | struct dlm_lock_resource *res) | |
2716 | { | |
2717 | if (!atomic_dec_and_lock(&res->asts_reserved, &res->spinlock)) | |
2718 | return; | |
2719 | ||
2720 | if (!res->migration_pending) { | |
2721 | spin_unlock(&res->spinlock); | |
2722 | return; | |
2723 | } | |
2724 | ||
2725 | BUG_ON(res->state & DLM_LOCK_RES_MIGRATING); | |
2726 | res->migration_pending = 0; | |
2727 | res->state |= DLM_LOCK_RES_MIGRATING; | |
2728 | spin_unlock(&res->spinlock); | |
2729 | wake_up(&res->wq); | |
2730 | wake_up(&dlm->migration_wq); | |
2731 | } |