aboutsummaryrefslogtreecommitdiff
path: root/fs/ocfs2/dlm/dlmast.c
blob: a795eb91f4ea396c1a4614e155cff885bc6770c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dlmast.c
 *
 * AST and BAST functionality for local and remote nodes
 *
 * Copyright (C) 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 *
 */


#include <linux/module.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/random.h>
#include <linux/blkdev.h>
#include <linux/socket.h>
#include <linux/inet.h>
#include <linux/spinlock.h>


#include "cluster/heartbeat.h"
#include "cluster/nodemanager.h"
#include "cluster/tcp.h"

#include "dlmapi.h"
#include "dlmcommon.h"

#define MLOG_MASK_PREFIX ML_DLM
#include "cluster/masklog.h"

static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
			   struct dlm_lock *lock);
static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock);

/* Should be called as an ast gets queued to see if the new
 * lock level will obsolete a pending bast.
 * For example, if dlm_thread queued a bast for an EX lock that
 * was blocking another EX, but before sending the bast the
 * lock owner downconverted to NL, the bast is now obsolete.
 * Only the ast should be sent.
 * This is needed because the lock and convert paths can queue
 * asts out-of-band (not waiting for dlm_thread) in order to
 * allow for LKM_NOQUEUE to get immediate responses. */
static int dlm_should_cancel_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
{
	assert_spin_locked(&dlm->ast_lock);
	assert_spin_locked(&lock->spinlock);

	if (lock->ml.highest_blocked == LKM_IVMODE)
		return 0;
	BUG_ON(lock->ml.highest_blocked == LKM_NLMODE);

	if (lock->bast_pending &&
	    list_empty(&lock->bast_list))
		/* old bast already sent, ok */
		return 0;

	if (lock->ml.type == LKM_EXMODE)
		/* EX blocks anything left, any bast still valid */
		return 0;
	else if (lock->ml.type == LKM_NLMODE)
		/* NL blocks nothing, no reason to send any bast, cancel it */
		return 1;
	else if (lock->ml.highest_blocked != LKM_EXMODE)
		/* PR only blocks EX */
		return 1;

	return 0;
}

static void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
{
	mlog_entry_void();

	BUG_ON(!dlm);
	BUG_ON(!lock);

	assert_spin_locked(&dlm->ast_lock);
	if (!list_empty(&lock->ast_list)) {
		mlog(ML_ERROR, "ast list not empty!!  pending=%d, newlevel=%d\n",
		     lock->ast_pending, lock->ml.type);
		BUG();
	}
	if (lock->ast_pending)
		mlog(0, "lock has an ast getting flushed right now\n");

	/* putting lock on list, add a ref */
	dlm_lock_get(lock);
	spin_lock(&lock->spinlock);

	/* check to see if this ast obsoletes the bast */
	if (dlm_should_cancel_bast(dlm, lock)) {
		struct dlm_lock_resource *res = lock->lockres;
		mlog(0, "%s: cancelling bast for %.*s\n",
		     dlm->name, res->lockname.len, res->lockname.name);
		lock->bast_pending = 0;
		list_del_init(&lock->bast_list);
		lock->ml.highest_blocked = LKM_IVMODE;
		/* removing lock from list, remove a ref.  guaranteed
		 * this won't be the last ref because of the get above,
		 * so res->spinlock will not be taken here */
		dlm_lock_put(lock);
		/* free up the reserved bast that we are cancelling.
		 * guaranteed that this will not be the last reserved
		 * ast because *both* an ast and a bast were reserved
		 * to get to this point.  the res->spinlock will not be
		 * taken here */
		dlm_lockres_release_ast(dlm, res);
	}
	list_add_tail(&lock->ast_list, &dlm->pending_asts);
	lock->ast_pending = 1;
	spin_unlock(&lock->spinlock);
}

void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
{
	mlog_entry_void();

	BUG_ON(!dlm);
	BUG_ON(!lock);

	spin_lock(&dlm->ast_lock);
	__dlm_queue_ast(dlm, lock);
	spin_unlock(&dlm->ast_lock);
}


static void __dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
{
	mlog_entry_void();

	BUG_ON(!dlm);
	BUG_ON(!lock);
	assert_spin_locked(&dlm->ast_lock);

	BUG_ON(!list_empty(&lock->bast_list));
	if (lock->bast_pending)
		mlog(0, "lock has a bast getting flushed right now\n");

	/* putting lock on list, add a ref */
	dlm_lock_get(lock);
	spin_lock(&lock->spinlock);
	list_add_tail(&lock->bast_list, &dlm->pending_basts);
	lock->bast_pending = 1;
	spin_unlock(&lock->spinlock);
}

void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock)
{
	mlog_entry_void();

	BUG_ON(!dlm);
	BUG_ON(!lock);

	spin_lock(&dlm->ast_lock);
	__dlm_queue_bast(dlm, lock);
	spin_unlock(&dlm->ast_lock);
}

static void dlm_update_lvb(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
			   struct dlm_lock *lock)
{
	struct dlm_lockstatus *lksb = lock->lksb;
	BUG_ON(!lksb);

	/* only updates if this node masters the lockres */
	if (res->owner == dlm->node_num) {

		spin_lock(&res->spinlock);
		/* check the lksb flags for the direction */
		if (lksb->flags & DLM_LKSB_GET_LVB) {
			mlog(0, "getting lvb from lockres for %s node\n",
				  lock->ml.node == dlm->node_num ? "master" :
				  "remote");
			memcpy(lksb->lvb, res->lvb, DLM_LVB_LEN);
		}
		/* Do nothing for lvb put requests - they should be done in
 		 * place when the lock is downconverted - otherwise we risk
 		 * racing gets and puts which could result in old lvb data
 		 * being propagated. We leave the put flag set and clear it
 		 * here. In the future we might want to clear it at the time
 		 * the put is actually done.
		 */
		spin_unlock(&res->spinlock);
	}

	/* reset any lvb flags on the lksb */
	lksb->flags &= ~(DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB);
}

void dlm_do_local_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
		      struct dlm_lock *lock)
{
	dlm_astlockfunc_t *fn;
	struct dlm_lockstatus *lksb;

	mlog_entry_void();

	lksb = lock->lksb;
	fn = lock->ast;
	BUG_ON(lock->ml.node != dlm->node_num);

	dlm_update_lvb(dlm, res, lock);
	(*fn)(lock->astdata);
}


int dlm_do_remote_ast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
		      struct dlm_lock *lock)
{
	int ret;
	struct dlm_lockstatus *lksb;
	int lksbflags;

	mlog_entry_void();

	lksb = lock->lksb;
	BUG_ON(lock->ml.node == dlm->node_num);

	lksbflags = lksb->flags;
	dlm_update_lvb(dlm, res, lock);

	/* lock request came from another node
	 * go do the ast over there */
	ret = dlm_send_proxy_ast(dlm, res, lock, lksbflags);
	return ret;
}

void dlm_do_local_bast(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
		       struct dlm_lock *lock, int blocked_type)
{
	dlm_bastlockfunc_t *fn = lock->bast;

	mlog_entry_void();
	BUG_ON(lock->ml.node != dlm->node_num);

	(*fn)(lock->astdata, blocked_type);
}



int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
			  void **ret_data)
{
	int ret;
	unsigned int locklen;
	struct dlm_ctxt *dlm = data;
	struct dlm_lock_resource *res = NULL;
	struct dlm_lock *lock = NULL;
	struct dlm_proxy_ast *past = (struct dlm_proxy_ast *) msg->buf;
	char *name;
	struct list_head *iter, *head=NULL;
	u64 cookie;
	u32 flags;
	u8 node;

	if (!dlm_grab(dlm)) {
		dlm_error(DLM_REJECTED);
		return DLM_REJECTED;
	}

	mlog_bug_on_msg(!dlm_domain_fully_joined(dlm),
			"Domain %s not fully joined!\n", dlm->name);

	name = past->name;
	locklen = past->namelen;
	cookie = past->cookie;
	flags = be32_to_cpu(past->flags);
	node = past->node_idx;

	if (locklen > DLM_LOCKID_NAME_MAX) {
		ret = DLM_IVBUFLEN;
		mlog(ML_ERROR, "Invalid name length (%d) in proxy ast "
		     "handler!\n", locklen);
		goto leave;
	}

	if ((flags & (LKM_PUT_LVB|LKM_GET_LVB)) ==
	     (LKM_PUT_LVB|LKM_GET_LVB)) {
		mlog(ML_ERROR, "Both PUT and GET lvb specified, (0x%x)\n",
		     flags);
		ret = DLM_BADARGS;
		goto leave;
	}

	mlog(0, "lvb: %s\n", flags & LKM_PUT_LVB ? "put lvb" :
		  (flags & LKM_GET_LVB ? "get lvb" : "none"));

	mlog(0, "type=%d, blocked_type=%d\n", past->type, past->blocked_type);

	if (past->type != DLM_AST &&
	    past->type != DLM_BAST) {
		mlog(ML_ERROR, "Unknown ast type! %d, cookie=%u:%llu"
		     "name=%.*s, node=%u\n", past->type,
		     dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
		     dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
		     locklen, name, node);
		ret = DLM_IVLOCKID;
		goto leave;
	}

	res = dlm_lookup_lockres(dlm, name, locklen);
	if (!res) {
		mlog(0, "Got %sast for unknown lockres! cookie=%u:%llu, "
		     "name=%.*s, node=%u\n", (past->type == DLM_AST ? "" : "b"),
		     dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
		     dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
		     locklen, name, node);
		ret = DLM_IVLOCKID;
		goto leave;
	}

	/* cannot get a proxy ast message if this node owns it */
	BUG_ON(res->owner == dlm->node_num);

	mlog(0, "lockres %.*s\n", res->lockname.len, res->lockname.name);

	spin_lock(&res->spinlock);
	if (res->state & DLM_LOCK_RES_RECOVERING) {
		mlog(0, "Responding with DLM_RECOVERING!\n");
		ret = DLM_RECOVERING;
		goto unlock_out;
	}
	if (res->state & DLM_LOCK_RES_MIGRATING) {
		mlog(0, "Responding with DLM_MIGRATING!\n");
		ret = DLM_MIGRATING;
		goto unlock_out;
	}
	/* try convert queue for both ast/bast */
	head = &res->converting;
	lock = NULL;
	list_for_each(iter, head) {
		lock = list_entry (iter, struct dlm_lock, list);
		if (lock->ml.cookie == cookie)
			goto do_ast;
	}

	/* if not on convert, try blocked for ast, granted for bast */
	if (past->type == DLM_AST)
		head = &res->blocked;
	else
		head = &res->granted;

	list_for_each(iter, head) {
		lock = list_entry (iter, struct dlm_lock, list);
		if (lock->ml.cookie == cookie)
			goto do_ast;
	}

	mlog(0, "Got %sast for unknown lock! cookie=%u:%llu, name=%.*s, "
	     "node=%u\n", past->type == DLM_AST ? "" : "b",
	     dlm_get_lock_cookie_node(be64_to_cpu(cookie)),
	     dlm_get_lock_cookie_seq(be64_to_cpu(cookie)),
	     locklen, name, node);

	ret = DLM_NORMAL;
unlock_out:
	spin_unlock(&res->spinlock);
	goto leave;

do_ast:
	ret = DLM_NORMAL;
	if (past->type == DLM_AST) {
		/* do not alter lock refcount.  switching lists. */
		list_move_tail(&lock->list, &res->granted);
		mlog(0, "ast: Adding to granted list... type=%d, "
		     "convert_type=%d\n", lock->ml.type, lock->ml.convert_type);
		if (lock->ml.convert_type != LKM_IVMODE) {
			lock->ml.type = lock->ml.convert_type;
			lock->ml.convert_type = LKM_IVMODE;
		} else {
			// should already be there....
		}

		lock->lksb->status = DLM_NORMAL;

		/* if we requested the lvb, fetch it into our lksb now */
		if (flags & LKM_GET_LVB) {
			BUG_ON(!(lock->lksb->flags & DLM_LKSB_GET_LVB));
			memcpy(lock->lksb->lvb, past->lvb, DLM_LVB_LEN);
		}
	}
	spin_unlock(&res->spinlock);

	if (past->type == DLM_AST)
		dlm_do_local_ast(dlm, res, lock);
	else
		dlm_do_local_bast(dlm, res, lock, past->blocked_type);

leave:
	if (res)
		dlm_lockres_put(res);

	dlm_put(dlm);
	return ret;
}



int 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)
{
	int ret = 0;
	struct dlm_proxy_ast past;
	struct kvec vec[2];
	size_t veclen = 1;
	int status;

	mlog_entry("res %.*s, to=%u, type=%d, blocked_type=%d\n",
		   res->lockname.len, res->lockname.name, lock->ml.node,
		   msg_type, blocked_type);

	memset(&past, 0, sizeof(struct dlm_proxy_ast));
	past.node_idx = dlm->node_num;
	past.type = msg_type;
	past.blocked_type = blocked_type;
	past.namelen = res->lockname.len;
	memcpy(past.name, res->lockname.name, past.namelen);
	past.cookie = lock->ml.cookie;

	vec[0].iov_len = sizeof(struct dlm_proxy_ast);
	vec[0].iov_base = &past;
	if (flags & DLM_LKSB_GET_LVB) {
		mlog(0, "returning requested LVB data\n");
		be32_add_cpu(&past.flags, LKM_GET_LVB);
		vec[1].iov_len = DLM_LVB_LEN;
		vec[1].iov_base = lock->lksb->lvb;
		veclen++;
	}

	ret = o2net_send_message_vec(DLM_PROXY_AST_MSG, dlm->key, vec, veclen,
				     lock->ml.node, &status);
	if (ret < 0)
		mlog_errno(ret);
	else {
		if (status == DLM_RECOVERING) {
			mlog(ML_ERROR, "sent AST to node %u, it thinks this "
			     "node is dead!\n", lock->ml.node);
			BUG();
		} else if (status == DLM_MIGRATING) {
			mlog(ML_ERROR, "sent AST to node %u, it returned "
			     "DLM_MIGRATING!\n", lock->ml.node);
			BUG();
		} else if (status != DLM_NORMAL && status != DLM_IVLOCKID) {
			mlog(ML_ERROR, "AST to node %u returned %d!\n",
			     lock->ml.node, status);
			/* ignore it */
		}
		ret = 0;
	}
	return ret;
}