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/highmem.h>
32 #include <linux/init.h>
33 #include <linux/sysctl.h>
34 #include <linux/random.h>
35 #include <linux/blkdev.h>
36 #include <linux/socket.h>
37 #include <linux/inet.h>
38 #include <linux/spinlock.h>
39
40
41 #include "cluster/heartbeat.h"
42 #include "cluster/nodemanager.h"
43 #include "cluster/tcp.h"
44
45 #include "dlmapi.h"
46 #include "dlmcommon.h"
47
48 #define MLOG_MASK_PREFIX ML_DLM
49 #include "cluster/masklog.h"
50
51 static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
52 struct dlm_lock *lock);
53 static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
54
55 /* Should be called as an ast gets queued to see if the new
56 * lock level will obsolete a pending bast.
57 * For example, if dlm_thread queued a bast for an EX lock that
58 * was blocking another EX, but before sending the bast the
59 * lock owner downconverted to NL, the bast is now obsolete.
60 * Only the ast should be sent.
61 * This is needed because the lock and convert paths can queue
62 * asts out-of-band (not waiting for dlm_thread) in order to
63 * allow for LKM_NOQUEUE to get immediate responses. */
dlm_should_cancel_bast(struct dlm_ctxt * dlm,struct dlm_lock * lock)64 static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
65 {
66 assert_spin_locked(&dlm->ast_lock);
67 assert_spin_locked(&lock->spinlock);
68
69 if (lock->ml.highest_blocked == LKM_IVMODE)
70 return 0;
71 BUG_ON(lock->ml.highest_blocked == LKM_NLMODE);
72
73 if (lock->bast_pending &&
74 list_empty(&lock->bast_list))
75 /* old bast already sent, ok */
76 return 0;
77
78 if (lock->ml.type == LKM_EXMODE)
79 /* EX blocks anything left, any bast still valid */
80 return 0;
81 else if (lock->ml.type == LKM_NLMODE)
82 /* NL blocks nothing, no reason to send any bast, cancel it */
83 return 1;
84 else if (lock->ml.highest_blocked != LKM_EXMODE)
85 /* PR only blocks EX */
86 return 1;
87
88 return 0;
89 }
90
__dlm_queue_ast(struct dlm_ctxt * dlm,struct dlm_lock * lock)91 void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
92 {
93 struct dlm_lock_resource *res;
94
95 BUG_ON(!dlm);
96 BUG_ON(!lock);
97
98 res = lock->lockres;
99
100 assert_spin_locked(&dlm->ast_lock);
101
102 if (!list_empty(&lock->ast_list)) {
103 mlog(ML_ERROR, "%s: res %.*s, lock %u:%llu, "
104 "AST list not empty, pending %d, newlevel %d\n",
105 dlm->name, res->lockname.len, res->lockname.name,
106 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
107 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
108 lock->ast_pending, lock->ml.type);
109 BUG();
110 }
111 if (lock->ast_pending)
112 mlog(0, "%s: res %.*s, lock %u:%llu, AST getting flushed\n",
113 dlm->name, res->lockname.len, res->lockname.name,
114 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
115 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
116
117 /* putting lock on list, add a ref */
118 dlm_lock_get(lock);
119 spin_lock(&lock->spinlock);
120
121 /* check to see if this ast obsoletes the bast */
122 if (dlm_should_cancel_bast(dlm, lock)) {
123 mlog(0, "%s: res %.*s, lock %u:%llu, Cancelling BAST\n",
124 dlm->name, res->lockname.len, res->lockname.name,
125 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
126 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
127 lock->bast_pending = 0;
128 list_del_init(&lock->bast_list);
129 lock->ml.highest_blocked = LKM_IVMODE;
130 /* removing lock from list, remove a ref. guaranteed
131 * this won't be the last ref because of the get above,
132 * so res->spinlock will not be taken here */
133 dlm_lock_put(lock);
134 /* free up the reserved bast that we are cancelling.
135 * guaranteed that this will not be the last reserved
136 * ast because *both* an ast and a bast were reserved
137 * to get to this point. the res->spinlock will not be
138 * taken here */
139 dlm_lockres_release_ast(dlm, res);
140 }
141 list_add_tail(&lock->ast_list, &dlm->pending_asts);
142 lock->ast_pending = 1;
143 spin_unlock(&lock->spinlock);
144 }
145
dlm_queue_ast(struct dlm_ctxt * dlm,struct dlm_lock * lock)146 void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
147 {
148 BUG_ON(!dlm);
149 BUG_ON(!lock);
150
151 spin_lock(&dlm->ast_lock);
152 __dlm_queue_ast(dlm, lock);
153 spin_unlock(&dlm->ast_lock);
154 }
155
156
__dlm_queue_bast(struct dlm_ctxt * dlm,struct dlm_lock * lock)157 void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
158 {
159 struct dlm_lock_resource *res;
160
161 BUG_ON(!dlm);
162 BUG_ON(!lock);
163
164 assert_spin_locked(&dlm->ast_lock);
165
166 res = lock->lockres;
167
168 BUG_ON(!list_empty(&lock->bast_list));
169 if (lock->bast_pending)
170 mlog(0, "%s: res %.*s, lock %u:%llu, BAST getting flushed\n",
171 dlm->name, res->lockname.len, res->lockname.name,
172 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
173 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
174
175 /* putting lock on list, add a ref */
176 dlm_lock_get(lock);
177 spin_lock(&lock->spinlock);
178 list_add_tail(&lock->bast_list, &dlm->pending_basts);
179 lock->bast_pending = 1;
180 spin_unlock(&lock->spinlock);
181 }
182
dlm_queue_bast(struct dlm_ctxt * dlm,struct dlm_lock * lock)183 void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
184 {
185 BUG_ON(!dlm);
186 BUG_ON(!lock);
187
188 spin_lock(&dlm->ast_lock);
189 __dlm_queue_bast(dlm, lock);
190 spin_unlock(&dlm->ast_lock);
191 }
192
dlm_update_lvb(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock)193 static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
194 struct dlm_lock *lock)
195 {
196 struct dlm_lockstatus *lksb = lock->lksb;
197 BUG_ON(!lksb);
198
199 /* only updates if this node masters the lockres */
200 spin_lock(&res->spinlock);
201 if (res->owner == dlm->node_num) {
202 /* check the lksb flags for the direction */
203 if (lksb->flags & DLM_LKSB_GET_LVB) {
204 mlog(0, "getting lvb from lockres for %s node\n",
205 lock->ml.node == dlm->node_num ? "master" :
206 "remote");
207 memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN);
208 }
209 /* Do nothing for lvb put requests - they should be done in
210 * place when the lock is downconverted - otherwise we risk
211 * racing gets and puts which could result in old lvb data
212 * being propagated. We leave the put flag set and clear it
213 * here. In the future we might want to clear it at the time
214 * the put is actually done.
215 */
216 }
217 spin_unlock(&res->spinlock);
218
219 /* reset any lvb flags on the lksb */
220 lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB);
221 }
222
dlm_do_local_ast(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock)223 void dlm_do_local_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
224 struct dlm_lock *lock)
225 {
226 dlm_astlockfunc_t *fn;
227 struct dlm_lockstatus *lksb;
228
229 mlog(0, "%s: res %.*s, lock %u:%llu, Local AST\n", dlm->name,
230 res->lockname.len, res->lockname.name,
231 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
232 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
233
234 lksb = lock->lksb;
235 fn = lock->ast;
236 BUG_ON(lock->ml.node != dlm->node_num);
237
238 dlm_update_lvb(dlm, res, lock);
239 (*fn)(lock->astdata);
240 }
241
242
dlm_do_remote_ast(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock)243 int dlm_do_remote_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
244 struct dlm_lock *lock)
245 {
246 int ret;
247 struct dlm_lockstatus *lksb;
248 int lksbflags;
249
250 mlog(0, "%s: res %.*s, lock %u:%llu, Remote AST\n", dlm->name,
251 res->lockname.len, res->lockname.name,
252 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
253 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)));
254
255 lksb = lock->lksb;
256 BUG_ON(lock->ml.node == dlm->node_num);
257
258 lksbflags = lksb->flags;
259 dlm_update_lvb(dlm, res, lock);
260
261 /* lock request came from another node
262 * go do the ast over there */
263 ret = dlm_send_proxy_ast(dlm, res, lock, lksbflags);
264 return ret;
265 }
266
dlm_do_local_bast(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock,int blocked_type)267 void dlm_do_local_bast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
268 struct dlm_lock *lock, int blocked_type)
269 {
270 dlm_bastlockfunc_t *fn = lock->bast;
271
272 BUG_ON(lock->ml.node != dlm->node_num);
273
274 mlog(0, "%s: res %.*s, lock %u:%llu, Local BAST, blocked %d\n",
275 dlm->name, res->lockname.len, res->lockname.name,
276 dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
277 dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
278 blocked_type);
279
280 (*fn)(lock->astdata, blocked_type);
281 }
282
283
284
dlm_proxy_ast_handler(struct o2net_msg * msg,u32 len,void * data,void ** ret_data)285 int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
286 void **ret_data)
287 {
288 int ret;
289 unsigned int locklen;
290 struct dlm_ctxt *dlm = data;
291 struct dlm_lock_resource *res = NULL;
292 struct dlm_lock *lock = NULL;
293 struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf;
294 char *name;
295 struct list_head *iter, *head=NULL;
296 u64 cookie;
297 u32 flags;
298 u8 node;
299
300 if (!dlm_grab(dlm)) {
301 dlm_error(DLM_REJECTED);
302 return DLM_REJECTED;
303 }
304
305 mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
306 "Domain %s not fully joined!\n", dlm->name);
307
308 name = past->name;
309 locklen = past->namelen;
310 cookie = past->cookie;
311 flags = be32_to_cpu(past->flags);
312 node = past->node_idx;
313
314 if (locklen > DLM_LOCKID_NAME_MAX) {
315 ret = DLM_IVBUFLEN;
316 mlog(ML_ERROR, "Invalid name length (%d) in proxy ast "
317 "handler!\n", locklen);
318 goto leave;
319 }
320
321 if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
322 (LKM_PUT_LVB|LKM_GET_LVB)) {
323 mlog(ML_ERROR, "Both PUT and GET lvb specified, (0x%x)\n",
324 flags);
325 ret = DLM_BADARGS;
326 goto leave;
327 }
328
329 mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
330 (flags & LKM_GET_LVB ? "get lvb" : "none"));
331
332 mlog(0, "type=%d, blocked_type=%d\n", past->type, past->blocked_type);
333
334 if (past->type != DLM_AST &&
335 past->type != DLM_BAST) {
336 mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu"
337 "name=%.*s, node=%u\n", past->type,
338 dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
339 dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
340 locklen, name, node);
341 ret = DLM_IVLOCKID;
342 goto leave;
343 }
344
345 res = dlm_lookup_lockres(dlm, name, locklen);
346 if (!res) {
347 mlog(0, "Got %sast for unknown lockres! cookie=%u:%llu, "
348 "name=%.*s, node=%u\n", (past->type == DLM_AST ? "" : "b"),
349 dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
350 dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
351 locklen, name, node);
352 ret = DLM_IVLOCKID;
353 goto leave;
354 }
355
356 /* cannot get a proxy ast message if this node owns it */
357 BUG_ON(res->owner == dlm->node_num);
358
359 mlog(0, "%s: res %.*s\n", dlm->name, res->lockname.len,
360 res->lockname.name);
361
362 spin_lock(&res->spinlock);
363 if (res->state & DLM_LOCK_RES_RECOVERING) {
364 mlog(0, "Responding with DLM_RECOVERING!\n");
365 ret = DLM_RECOVERING;
366 goto unlock_out;
367 }
368 if (res->state & DLM_LOCK_RES_MIGRATING) {
369 mlog(0, "Responding with DLM_MIGRATING!\n");
370 ret = DLM_MIGRATING;
371 goto unlock_out;
372 }
373 /* try convert queue for both ast/bast */
374 head = &res->converting;
375 lock = NULL;
376 list_for_each(iter, head) {
377 lock = list_entry (iter, struct dlm_lock, list);
378 if (lock->ml.cookie == cookie)
379 goto do_ast;
380 }
381
382 /* if not on convert, try blocked for ast, granted for bast */
383 if (past->type == DLM_AST)
384 head = &res->blocked;
385 else
386 head = &res->granted;
387
388 list_for_each(iter, head) {
389 lock = list_entry (iter, struct dlm_lock, list);
390 if (lock->ml.cookie == cookie)
391 goto do_ast;
392 }
393
394 mlog(0, "Got %sast for unknown lock! cookie=%u:%llu, name=%.*s, "
395 "node=%u\n", past->type == DLM_AST ? "" : "b",
396 dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
397 dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
398 locklen, name, node);
399
400 ret = DLM_NORMAL;
401 unlock_out:
402 spin_unlock(&res->spinlock);
403 goto leave;
404
405 do_ast:
406 ret = DLM_NORMAL;
407 if (past->type == DLM_AST) {
408 /* do not alter lock refcount. switching lists. */
409 list_move_tail(&lock->list, &res->granted);
410 mlog(0, "%s: res %.*s, lock %u:%llu, Granted type %d => %d\n",
411 dlm->name, res->lockname.len, res->lockname.name,
412 dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
413 dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
414 lock->ml.type, lock->ml.convert_type);
415
416 if (lock->ml.convert_type != LKM_IVMODE) {
417 lock->ml.type = lock->ml.convert_type;
418 lock->ml.convert_type = LKM_IVMODE;
419 } else {
420 // should already be there....
421 }
422
423 lock->lksb->status = DLM_NORMAL;
424
425 /* if we requested the lvb, fetch it into our lksb now */
426 if (flags & LKM_GET_LVB) {
427 BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB));
428 memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN);
429 }
430 }
431 spin_unlock(&res->spinlock);
432
433 if (past->type == DLM_AST)
434 dlm_do_local_ast(dlm, res, lock);
435 else
436 dlm_do_local_bast(dlm, res, lock, past->blocked_type);
437
438 leave:
439 if (res)
440 dlm_lockres_put(res);
441
442 dlm_put(dlm);
443 return ret;
444 }
445
446
447
dlm_send_proxy_ast_msg(struct dlm_ctxt * dlm,struct dlm_lock_resource * res,struct dlm_lock * lock,int msg_type,int blocked_type,int flags)448 int dlm_send_proxy_ast_msg(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
449 struct dlm_lock *lock, int msg_type,
450 int blocked_type, int flags)
451 {
452 int ret = 0;
453 struct dlm_proxy_ast past;
454 struct kvec vec[2];
455 size_t veclen = 1;
456 int status;
457
458 mlog(0, "%s: res %.*s, to %u, type %d, blocked_type %d\n", dlm->name,
459 res->lockname.len, res->lockname.name, lock->ml.node, msg_type,
460 blocked_type);
461
462 memset(&past, 0, sizeof(struct dlm_proxy_ast));
463 past.node_idx = dlm->node_num;
464 past.type = msg_type;
465 past.blocked_type = blocked_type;
466 past.namelen = res->lockname.len;
467 memcpy(past.name, res->lockname.name, past.namelen);
468 past.cookie = lock->ml.cookie;
469
470 vec[0].iov_len = sizeof(struct dlm_proxy_ast);
471 vec[0].iov_base = &past;
472 if (flags & DLM_LKSB_GET_LVB) {
473 be32_add_cpu(&past.flags, LKM_GET_LVB);
474 vec[1].iov_len = DLM_LVB_LEN;
475 vec[1].iov_base = lock->lksb->lvb;
476 veclen++;
477 }
478
479 ret = o2net_send_message_vec(DLM_PROXY_AST_MSG, dlm->key, vec, veclen,
480 lock->ml.node, &status);
481 if (ret < 0)
482 mlog(ML_ERROR, "%s: res %.*s, error %d send AST to node %u\n",
483 dlm->name, res->lockname.len, res->lockname.name, ret,
484 lock->ml.node);
485 else {
486 if (status == DLM_RECOVERING) {
487 mlog(ML_ERROR, "sent AST to node %u, it thinks this "
488 "node is dead!\n", lock->ml.node);
489 BUG();
490 } else if (status == DLM_MIGRATING) {
491 mlog(ML_ERROR, "sent AST to node %u, it returned "
492 "DLM_MIGRATING!\n", lock->ml.node);
493 BUG();
494 } else if (status != DLM_NORMAL && status != DLM_IVLOCKID) {
495 mlog(ML_ERROR, "AST to node %u returned %d!\n",
496 lock->ml.node, status);
497 /* ignore it */
498 }
499 ret = 0;
500 }
501 return ret;
502 }
503