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1 | /* -*- mode: c; c-basic-offset: 8; -*- |
2 | * vim: noexpandtab sw=8 ts=8 sts=0: | |
3 | * | |
4 | * dlmast.c | |
5 | * | |
6 | * AST and BAST functionality for local and remote nodes | |
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 | ||
42 | ||
43 | #include "cluster/heartbeat.h" | |
44 | #include "cluster/nodemanager.h" | |
45 | #include "cluster/tcp.h" | |
46 | #include "cluster/endian.h" | |
47 | ||
48 | #include "dlmapi.h" | |
49 | #include "dlmcommon.h" | |
50 | ||
51 | #define MLOG_MASK_PREFIX ML_DLM | |
52 | #include "cluster/masklog.h" | |
53 | ||
54 | static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, | |
55 | struct dlm_lock *lock); | |
56 | static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock); | |
57 | ||
58 | /* Should be called as an ast gets queued to see if the new | |
59 | * lock level will obsolete a pending bast. | |
60 | * For example, if dlm_thread queued a bast for an EX lock that | |
61 | * was blocking another EX, but before sending the bast the | |
62 | * lock owner downconverted to NL, the bast is now obsolete. | |
63 | * Only the ast should be sent. | |
64 | * This is needed because the lock and convert paths can queue | |
65 | * asts out-of-band (not waiting for dlm_thread) in order to | |
66 | * allow for LKM_NOQUEUE to get immediate responses. */ | |
67 | static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) | |
68 | { | |
69 | assert_spin_locked(&dlm->ast_lock); | |
70 | assert_spin_locked(&lock->spinlock); | |
71 | ||
72 | if (lock->ml.highest_blocked == LKM_IVMODE) | |
73 | return 0; | |
74 | BUG_ON(lock->ml.highest_blocked == LKM_NLMODE); | |
75 | ||
76 | if (lock->bast_pending && | |
77 | list_empty(&lock->bast_list)) | |
78 | /* old bast already sent, ok */ | |
79 | return 0; | |
80 | ||
81 | if (lock->ml.type == LKM_EXMODE) | |
82 | /* EX blocks anything left, any bast still valid */ | |
83 | return 0; | |
84 | else if (lock->ml.type == LKM_NLMODE) | |
85 | /* NL blocks nothing, no reason to send any bast, cancel it */ | |
86 | return 1; | |
87 | else if (lock->ml.highest_blocked != LKM_EXMODE) | |
88 | /* PR only blocks EX */ | |
89 | return 1; | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | static void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock) | |
95 | { | |
96 | mlog_entry_void(); | |
97 | ||
98 | BUG_ON(!dlm); | |
99 | BUG_ON(!lock); | |
100 | ||
101 | assert_spin_locked(&dlm->ast_lock); | |
102 | if (!list_empty(&lock->ast_list)) { | |
103 | mlog(ML_ERROR, "ast list not empty!! pending=%d, newlevel=%d\n", | |
104 | lock->ast_pending, lock->ml.type); | |
105 | BUG(); | |
106 | } | |
107 | BUG_ON(!list_empty(&lock->ast_list)); | |
108 | if (lock->ast_pending) | |
109 | mlog(0, "lock has an ast getting flushed right now\n"); | |
110 | ||
111 | /* putting lock on list, add a ref */ | |
112 | dlm_lock_get(lock); | |
113 | spin_lock(&lock->spinlock); | |
114 | ||
115 | /* check to see if this ast obsoletes the bast */ | |
116 | if (dlm_should_cancel_bast(dlm, lock)) { | |
117 | struct dlm_lock_resource *res = lock->lockres; | |
118 | mlog(0, "%s: cancelling bast for %.*s\n", | |
119 | dlm->name, res->lockname.len, res->lockname.name); | |
120 | lock->bast_pending = 0; | |
121 | list_del_init(&lock->bast_list); | |
122 | lock->ml.highest_blocked = LKM_IVMODE; | |
123 | /* removing lock from list, remove a ref. guaranteed | |
124 | * this won't be the last ref because of the get above, | |
125 | * so res->spinlock will not be taken here */ | |
126 | dlm_lock_put(lock); | |
127 | /* free up the reserved bast that we are cancelling. | |
128 | * guaranteed that this will not be the last reserved | |
129 | * ast because *both* an ast and a bast were reserved | |
130 | * to get to this point. the res->spinlock will not be | |
131 | * taken here */ | |
132 | dlm_lockres_release_ast(dlm, res); | |
133 | } | |
134 | list_add_tail(&lock->ast_list, &dlm->pending_asts); | |
135 | lock->ast_pending = 1; | |
136 | spin_unlock(&lock->spinlock); | |
137 | } | |
138 | ||
139 | void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock) | |
140 | { | |
141 | mlog_entry_void(); | |
142 | ||
143 | BUG_ON(!dlm); | |
144 | BUG_ON(!lock); | |
145 | ||
146 | spin_lock(&dlm->ast_lock); | |
147 | __dlm_queue_ast(dlm, lock); | |
148 | spin_unlock(&dlm->ast_lock); | |
149 | } | |
150 | ||
151 | ||
152 | static void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) | |
153 | { | |
154 | mlog_entry_void(); | |
155 | ||
156 | BUG_ON(!dlm); | |
157 | BUG_ON(!lock); | |
158 | assert_spin_locked(&dlm->ast_lock); | |
159 | ||
160 | BUG_ON(!list_empty(&lock->bast_list)); | |
161 | if (lock->bast_pending) | |
162 | mlog(0, "lock has a bast getting flushed right now\n"); | |
163 | ||
164 | /* putting lock on list, add a ref */ | |
165 | dlm_lock_get(lock); | |
166 | spin_lock(&lock->spinlock); | |
167 | list_add_tail(&lock->bast_list, &dlm->pending_basts); | |
168 | lock->bast_pending = 1; | |
169 | spin_unlock(&lock->spinlock); | |
170 | } | |
171 | ||
172 | void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock) | |
173 | { | |
174 | mlog_entry_void(); | |
175 | ||
176 | BUG_ON(!dlm); | |
177 | BUG_ON(!lock); | |
178 | ||
179 | spin_lock(&dlm->ast_lock); | |
180 | __dlm_queue_bast(dlm, lock); | |
181 | spin_unlock(&dlm->ast_lock); | |
182 | } | |
183 | ||
184 | static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, | |
185 | struct dlm_lock *lock) | |
186 | { | |
187 | struct dlm_lockstatus *lksb = lock->lksb; | |
188 | BUG_ON(!lksb); | |
189 | ||
190 | /* only updates if this node masters the lockres */ | |
191 | if (res->owner == dlm->node_num) { | |
192 | ||
193 | spin_lock(&res->spinlock); | |
194 | /* check the lksb flags for the direction */ | |
195 | if (lksb->flags & DLM_LKSB_GET_LVB) { | |
196 | mlog(0, "getting lvb from lockres for %s node\n", | |
197 | lock->ml.node == dlm->node_num ? "master" : | |
198 | "remote"); | |
199 | memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN); | |
200 | } else if (lksb->flags & DLM_LKSB_PUT_LVB) { | |
201 | mlog(0, "setting lvb from lockres for %s node\n", | |
202 | lock->ml.node == dlm->node_num ? "master" : | |
203 | "remote"); | |
204 | memcpy(res->lvb, lksb->lvb, DLM_LVB_LEN); | |
205 | } | |
206 | spin_unlock(&res->spinlock); | |
207 | } | |
208 | ||
209 | /* reset any lvb flags on the lksb */ | |
210 | lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB); | |
211 | } | |
212 | ||
213 | void dlm_do_local_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, | |
214 | struct dlm_lock *lock) | |
215 | { | |
216 | dlm_astlockfunc_t *fn; | |
217 | struct dlm_lockstatus *lksb; | |
218 | ||
219 | mlog_entry_void(); | |
220 | ||
221 | lksb = lock->lksb; | |
222 | fn = lock->ast; | |
223 | BUG_ON(lock->ml.node != dlm->node_num); | |
224 | ||
225 | dlm_update_lvb(dlm, res, lock); | |
226 | (*fn)(lock->astdata); | |
227 | } | |
228 | ||
229 | ||
230 | int dlm_do_remote_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, | |
231 | struct dlm_lock *lock) | |
232 | { | |
233 | int ret; | |
234 | struct dlm_lockstatus *lksb; | |
235 | int lksbflags; | |
236 | ||
237 | mlog_entry_void(); | |
238 | ||
239 | lksb = lock->lksb; | |
240 | BUG_ON(lock->ml.node == dlm->node_num); | |
241 | ||
242 | lksbflags = lksb->flags; | |
243 | dlm_update_lvb(dlm, res, lock); | |
244 | ||
245 | /* lock request came from another node | |
246 | * go do the ast over there */ | |
247 | ret = dlm_send_proxy_ast(dlm, res, lock, lksbflags); | |
248 | return ret; | |
249 | } | |
250 | ||
251 | void dlm_do_local_bast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, | |
252 | struct dlm_lock *lock, int blocked_type) | |
253 | { | |
254 | dlm_bastlockfunc_t *fn = lock->bast; | |
255 | ||
256 | mlog_entry_void(); | |
257 | BUG_ON(lock->ml.node != dlm->node_num); | |
258 | ||
259 | (*fn)(lock->astdata, blocked_type); | |
260 | } | |
261 | ||
262 | ||
263 | ||
264 | int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data) | |
265 | { | |
266 | int ret; | |
267 | unsigned int locklen; | |
268 | struct dlm_ctxt *dlm = data; | |
269 | struct dlm_lock_resource *res = NULL; | |
270 | struct dlm_lock *lock = NULL; | |
271 | struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf; | |
272 | char *name; | |
273 | struct list_head *iter, *head=NULL; | |
274 | u64 cookie; | |
275 | u32 flags; | |
276 | ||
277 | if (!dlm_grab(dlm)) { | |
278 | dlm_error(DLM_REJECTED); | |
279 | return DLM_REJECTED; | |
280 | } | |
281 | ||
282 | mlog_bug_on_msg(!dlm_domain_fully_joined(dlm), | |
283 | "Domain %s not fully joined!\n", dlm->name); | |
284 | ||
285 | name = past->name; | |
286 | locklen = past->namelen; | |
287 | cookie = be64_to_cpu(past->cookie); | |
288 | flags = be32_to_cpu(past->flags); | |
289 | ||
290 | if (locklen > DLM_LOCKID_NAME_MAX) { | |
291 | ret = DLM_IVBUFLEN; | |
292 | mlog(ML_ERROR, "Invalid name length in proxy ast handler!\n"); | |
293 | goto leave; | |
294 | } | |
295 | ||
296 | if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) == | |
297 | (LKM_PUT_LVB|LKM_GET_LVB)) { | |
298 | mlog(ML_ERROR, "both PUT and GET lvb specified\n"); | |
299 | ret = DLM_BADARGS; | |
300 | goto leave; | |
301 | } | |
302 | ||
303 | mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" : | |
304 | (flags & LKM_GET_LVB ? "get lvb" : "none")); | |
305 | ||
306 | mlog(0, "type=%d, blocked_type=%d\n", past->type, past->blocked_type); | |
307 | ||
308 | if (past->type != DLM_AST && | |
309 | past->type != DLM_BAST) { | |
29004858 KH |
310 | mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu" |
311 | "name=%.*s\n", past->type, | |
312 | dlm_get_lock_cookie_node(cookie), | |
313 | dlm_get_lock_cookie_seq(cookie), | |
314 | locklen, name); | |
6714d8e8 KH |
315 | ret = DLM_IVLOCKID; |
316 | goto leave; | |
317 | } | |
318 | ||
319 | res = dlm_lookup_lockres(dlm, name, locklen); | |
320 | if (!res) { | |
321 | mlog(ML_ERROR, "got %sast for unknown lockres! " | |
29004858 | 322 | "cookie=%u:%llu, name=%.*s, namelen=%u\n", |
6714d8e8 | 323 | past->type == DLM_AST ? "" : "b", |
29004858 KH |
324 | dlm_get_lock_cookie_node(cookie), |
325 | dlm_get_lock_cookie_seq(cookie), | |
326 | locklen, name, locklen); | |
6714d8e8 KH |
327 | ret = DLM_IVLOCKID; |
328 | goto leave; | |
329 | } | |
330 | ||
331 | /* cannot get a proxy ast message if this node owns it */ | |
332 | BUG_ON(res->owner == dlm->node_num); | |
333 | ||
334 | mlog(0, "lockres %.*s\n", res->lockname.len, res->lockname.name); | |
335 | ||
336 | spin_lock(&res->spinlock); | |
337 | if (res->state & DLM_LOCK_RES_RECOVERING) { | |
338 | mlog(0, "responding with DLM_RECOVERING!\n"); | |
339 | ret = DLM_RECOVERING; | |
340 | goto unlock_out; | |
341 | } | |
342 | if (res->state & DLM_LOCK_RES_MIGRATING) { | |
343 | mlog(0, "responding with DLM_MIGRATING!\n"); | |
344 | ret = DLM_MIGRATING; | |
345 | goto unlock_out; | |
346 | } | |
347 | /* try convert queue for both ast/bast */ | |
348 | head = &res->converting; | |
349 | lock = NULL; | |
350 | list_for_each(iter, head) { | |
351 | lock = list_entry (iter, struct dlm_lock, list); | |
352 | if (be64_to_cpu(lock->ml.cookie) == cookie) | |
353 | goto do_ast; | |
354 | } | |
355 | ||
356 | /* if not on convert, try blocked for ast, granted for bast */ | |
357 | if (past->type == DLM_AST) | |
358 | head = &res->blocked; | |
359 | else | |
360 | head = &res->granted; | |
361 | ||
362 | list_for_each(iter, head) { | |
363 | lock = list_entry (iter, struct dlm_lock, list); | |
364 | if (be64_to_cpu(lock->ml.cookie) == cookie) | |
365 | goto do_ast; | |
366 | } | |
367 | ||
29004858 KH |
368 | mlog(ML_ERROR, "got %sast for unknown lock! cookie=%u:%llu, " |
369 | "name=%.*s, namelen=%u\n", | |
370 | past->type == DLM_AST ? "" : "b", | |
371 | dlm_get_lock_cookie_node(cookie), | |
372 | dlm_get_lock_cookie_seq(cookie), | |
373 | locklen, name, locklen); | |
6714d8e8 KH |
374 | |
375 | ret = DLM_NORMAL; | |
376 | unlock_out: | |
377 | spin_unlock(&res->spinlock); | |
378 | goto leave; | |
379 | ||
380 | do_ast: | |
381 | ret = DLM_NORMAL; | |
382 | if (past->type == DLM_AST) { | |
383 | /* do not alter lock refcount. switching lists. */ | |
f116629d | 384 | list_move_tail(&lock->list, &res->granted); |
6714d8e8 KH |
385 | mlog(0, "ast: adding to granted list... type=%d, " |
386 | "convert_type=%d\n", lock->ml.type, lock->ml.convert_type); | |
387 | if (lock->ml.convert_type != LKM_IVMODE) { | |
388 | lock->ml.type = lock->ml.convert_type; | |
389 | lock->ml.convert_type = LKM_IVMODE; | |
390 | } else { | |
391 | // should already be there.... | |
392 | } | |
393 | ||
394 | lock->lksb->status = DLM_NORMAL; | |
395 | ||
396 | /* if we requested the lvb, fetch it into our lksb now */ | |
397 | if (flags & LKM_GET_LVB) { | |
398 | BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB)); | |
399 | memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN); | |
400 | } | |
401 | } | |
402 | spin_unlock(&res->spinlock); | |
403 | ||
404 | if (past->type == DLM_AST) | |
405 | dlm_do_local_ast(dlm, res, lock); | |
406 | else | |
407 | dlm_do_local_bast(dlm, res, lock, past->blocked_type); | |
408 | ||
409 | leave: | |
410 | ||
411 | if (res) | |
412 | dlm_lockres_put(res); | |
413 | ||
414 | dlm_put(dlm); | |
415 | return ret; | |
416 | } | |
417 | ||
418 | ||
419 | ||
420 | int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm, struct dlm_lock_resource *res, | |
421 | struct dlm_lock *lock, int msg_type, | |
422 | int blocked_type, int flags) | |
423 | { | |
424 | int ret = 0; | |
425 | struct dlm_proxy_ast past; | |
426 | struct kvec vec[2]; | |
427 | size_t veclen = 1; | |
428 | int status; | |
429 | ||
430 | mlog_entry("res %.*s, to=%u, type=%d, blocked_type=%d\n", | |
431 | res->lockname.len, res->lockname.name, lock->ml.node, | |
432 | msg_type, blocked_type); | |
433 | ||
434 | memset(&past, 0, sizeof(struct dlm_proxy_ast)); | |
435 | past.node_idx = dlm->node_num; | |
436 | past.type = msg_type; | |
437 | past.blocked_type = blocked_type; | |
438 | past.namelen = res->lockname.len; | |
439 | memcpy(past.name, res->lockname.name, past.namelen); | |
440 | past.cookie = lock->ml.cookie; | |
441 | ||
442 | vec[0].iov_len = sizeof(struct dlm_proxy_ast); | |
443 | vec[0].iov_base = &past; | |
444 | if (flags & DLM_LKSB_GET_LVB) { | |
445 | mlog(0, "returning requested LVB data\n"); | |
446 | be32_add_cpu(&past.flags, LKM_GET_LVB); | |
447 | vec[1].iov_len = DLM_LVB_LEN; | |
448 | vec[1].iov_base = lock->lksb->lvb; | |
449 | veclen++; | |
450 | } | |
451 | ||
452 | ret = o2net_send_message_vec(DLM_PROXY_AST_MSG, dlm->key, vec, veclen, | |
453 | lock->ml.node, &status); | |
454 | if (ret < 0) | |
455 | mlog_errno(ret); | |
456 | else { | |
457 | if (status == DLM_RECOVERING) { | |
458 | mlog(ML_ERROR, "sent AST to node %u, it thinks this " | |
459 | "node is dead!\n", lock->ml.node); | |
460 | BUG(); | |
461 | } else if (status == DLM_MIGRATING) { | |
462 | mlog(ML_ERROR, "sent AST to node %u, it returned " | |
463 | "DLM_MIGRATING!\n", lock->ml.node); | |
464 | BUG(); | |
465 | } else if (status != DLM_NORMAL) { | |
466 | mlog(ML_ERROR, "AST to node %u returned %d!\n", | |
467 | lock->ml.node, status); | |
468 | /* ignore it */ | |
469 | } | |
470 | ret = 0; | |
471 | } | |
472 | return ret; | |
473 | } |