aboutsummaryrefslogtreecommitdiff
path: root/fs/ocfs2/stack_o2cb.c
blob: 3038c92af4939438ab065f9f8cb123bc3c66a8b6 (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
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * stack_o2cb.c
 *
 * Code which interfaces ocfs2 with the o2cb stack.
 *
 * Copyright (C) 2007 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, version 2.
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/crc32.h>
#include <linux/module.h>

/* Needed for AOP_TRUNCATED_PAGE in mlog_errno() */
#include <linux/fs.h>

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

#include "stackglue.h"

struct o2dlm_private {
	struct dlm_eviction_cb op_eviction_cb;
};

static struct ocfs2_stack_plugin o2cb_stack;

/* These should be identical */
#if (DLM_LOCK_IV != LKM_IVMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_NL != LKM_NLMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_CR != LKM_CRMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_CW != LKM_CWMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_PR != LKM_PRMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_PW != LKM_PWMODE)
# error Lock modes do not match
#endif
#if (DLM_LOCK_EX != LKM_EXMODE)
# error Lock modes do not match
#endif
static inline int mode_to_o2dlm(int mode)
{
	BUG_ON(mode > LKM_MAXMODE);

	return mode;
}

#define map_flag(_generic, _o2dlm)		\
	if (flags & (_generic)) {		\
		flags &= ~(_generic);		\
		o2dlm_flags |= (_o2dlm);	\
	}
static int flags_to_o2dlm(u32 flags)
{
	int o2dlm_flags = 0;

	map_flag(DLM_LKF_NOQUEUE, LKM_NOQUEUE);
	map_flag(DLM_LKF_CANCEL, LKM_CANCEL);
	map_flag(DLM_LKF_CONVERT, LKM_CONVERT);
	map_flag(DLM_LKF_VALBLK, LKM_VALBLK);
	map_flag(DLM_LKF_IVVALBLK, LKM_INVVALBLK);
	map_flag(DLM_LKF_ORPHAN, LKM_ORPHAN);
	map_flag(DLM_LKF_FORCEUNLOCK, LKM_FORCE);
	map_flag(DLM_LKF_TIMEOUT, LKM_TIMEOUT);
	map_flag(DLM_LKF_LOCAL, LKM_LOCAL);

	/* map_flag() should have cleared every flag passed in */
	BUG_ON(flags != 0);

	return o2dlm_flags;
}
#undef map_flag

/*
 * Map an o2dlm status to standard errno values.
 *
 * o2dlm only uses a handful of these, and returns even fewer to the
 * caller. Still, we try to assign sane values to each error.
 *
 * The following value pairs have special meanings to dlmglue, thus
 * the right hand side needs to stay unique - never duplicate the
 * mapping elsewhere in the table!
 *
 * DLM_NORMAL:		0
 * DLM_NOTQUEUED:	-EAGAIN
 * DLM_CANCELGRANT:	-EBUSY
 * DLM_CANCEL:		-DLM_ECANCEL
 */
/* Keep in sync with dlmapi.h */
static int status_map[] = {
	[DLM_NORMAL]			= 0,		/* Success */
	[DLM_GRANTED]			= -EINVAL,
	[DLM_DENIED]			= -EACCES,
	[DLM_DENIED_NOLOCKS]		= -EACCES,
	[DLM_WORKING]			= -EACCES,
	[DLM_BLOCKED]			= -EINVAL,
	[DLM_BLOCKED_ORPHAN]		= -EINVAL,
	[DLM_DENIED_GRACE_PERIOD]	= -EACCES,
	[DLM_SYSERR]			= -ENOMEM,	/* It is what it is */
	[DLM_NOSUPPORT]			= -EPROTO,
	[DLM_CANCELGRANT]		= -EBUSY,	/* Cancel after grant */
	[DLM_IVLOCKID]			= -EINVAL,
	[DLM_SYNC]			= -EINVAL,
	[DLM_BADTYPE]			= -EINVAL,
	[DLM_BADRESOURCE]		= -EINVAL,
	[DLM_MAXHANDLES]		= -ENOMEM,
	[DLM_NOCLINFO]			= -EINVAL,
	[DLM_NOLOCKMGR]			= -EINVAL,
	[DLM_NOPURGED]			= -EINVAL,
	[DLM_BADARGS]			= -EINVAL,
	[DLM_VOID]			= -EINVAL,
	[DLM_NOTQUEUED]			= -EAGAIN,	/* Trylock failed */
	[DLM_IVBUFLEN]			= -EINVAL,
	[DLM_CVTUNGRANT]		= -EPERM,
	[DLM_BADPARAM]			= -EINVAL,
	[DLM_VALNOTVALID]		= -EINVAL,
	[DLM_REJECTED]			= -EPERM,
	[DLM_ABORT]			= -EINVAL,
	[DLM_CANCEL]			= -DLM_ECANCEL,	/* Successful cancel */
	[DLM_IVRESHANDLE]		= -EINVAL,
	[DLM_DEADLOCK]			= -EDEADLK,
	[DLM_DENIED_NOASTS]		= -EINVAL,
	[DLM_FORWARD]			= -EINVAL,
	[DLM_TIMEOUT]			= -ETIMEDOUT,
	[DLM_IVGROUPID]			= -EINVAL,
	[DLM_VERS_CONFLICT]		= -EOPNOTSUPP,
	[DLM_BAD_DEVICE_PATH]		= -ENOENT,
	[DLM_NO_DEVICE_PERMISSION]	= -EPERM,
	[DLM_NO_CONTROL_DEVICE]		= -ENOENT,
	[DLM_RECOVERING]		= -ENOTCONN,
	[DLM_MIGRATING]			= -ERESTART,
	[DLM_MAXSTATS]			= -EINVAL,
};

static int dlm_status_to_errno(enum dlm_status status)
{
	BUG_ON(status < 0 || status >= ARRAY_SIZE(status_map));

	return status_map[status];
}

static void o2dlm_lock_ast_wrapper(void *astarg)
{
	BUG_ON(o2cb_stack.sp_proto == NULL);

	o2cb_stack.sp_proto->lp_lock_ast(astarg);
}

static void o2dlm_blocking_ast_wrapper(void *astarg, int level)
{
	BUG_ON(o2cb_stack.sp_proto == NULL);

	o2cb_stack.sp_proto->lp_blocking_ast(astarg, level);
}

static void o2dlm_unlock_ast_wrapper(void *astarg, enum dlm_status status)
{
	int error = dlm_status_to_errno(status);

	BUG_ON(o2cb_stack.sp_proto == NULL);

	/*
	 * In o2dlm, you can get both the lock_ast() for the lock being
	 * granted and the unlock_ast() for the CANCEL failing.  A
	 * successful cancel sends DLM_NORMAL here.  If the
	 * lock grant happened before the cancel arrived, you get
	 * DLM_CANCELGRANT.
	 *
	 * There's no need for the double-ast.  If we see DLM_CANCELGRANT,
	 * we just ignore it.  We expect the lock_ast() to handle the
	 * granted lock.
	 */
	if (status == DLM_CANCELGRANT)
		return;

	o2cb_stack.sp_proto->lp_unlock_ast(astarg, error);
}

static int o2cb_dlm_lock(struct ocfs2_cluster_connection *conn,
			 int mode,
			 union ocfs2_dlm_lksb *lksb,
			 u32 flags,
			 void *name,
			 unsigned int namelen,
			 void *astarg)
{
	enum dlm_status status;
	int o2dlm_mode = mode_to_o2dlm(mode);
	int o2dlm_flags = flags_to_o2dlm(flags);
	int ret;

	status = dlmlock(conn->cc_lockspace, o2dlm_mode, &lksb->lksb_o2dlm,
			 o2dlm_flags, name, namelen,
			 o2dlm_lock_ast_wrapper, astarg,
			 o2dlm_blocking_ast_wrapper);
	ret = dlm_status_to_errno(status);
	return ret;
}

static int o2cb_dlm_unlock(struct ocfs2_cluster_connection *conn,
			   union ocfs2_dlm_lksb *lksb,
			   u32 flags,
			   void *astarg)
{
	enum dlm_status status;
	int o2dlm_flags = flags_to_o2dlm(flags);
	int ret;

	status = dlmunlock(conn->cc_lockspace, &lksb->lksb_o2dlm,
			   o2dlm_flags, o2dlm_unlock_ast_wrapper, astarg);
	ret = dlm_status_to_errno(status);
	return ret;
}

static int o2cb_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
{
	return dlm_status_to_errno(lksb->lksb_o2dlm.status);
}

/*
 * o2dlm aways has a "valid" LVB. If the dlm loses track of the LVB
 * contents, it will zero out the LVB.  Thus the caller can always trust
 * the contents.
 */
static int o2cb_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb)
{
	return 1;
}

static void *o2cb_dlm_lvb(union ocfs2_dlm_lksb *lksb)
{
	return (void *)(lksb->lksb_o2dlm.lvb);
}

static void o2cb_dump_lksb(union ocfs2_dlm_lksb *lksb)
{
	dlm_print_one_lock(lksb->lksb_o2dlm.lockid);
}

/*
 * Called from the dlm when it's about to evict a node. This is how the
 * classic stack signals node death.
 */
static void o2dlm_eviction_cb(int node_num, void *data)
{
	struct ocfs2_cluster_connection *conn = data;

	mlog(ML_NOTICE, "o2dlm has evicted node %d from group %.*s\n",
	     node_num, conn->cc_namelen, conn->cc_name);

	conn->cc_recovery_handler(node_num, conn->cc_recovery_data);
}

static int o2cb_cluster_connect(struct ocfs2_cluster_connection *conn)
{
	int rc = 0;
	u32 dlm_key;
	struct dlm_ctxt *dlm;
	struct o2dlm_private *priv;
	struct dlm_protocol_version fs_version;

	BUG_ON(conn == NULL);
	BUG_ON(o2cb_stack.sp_proto == NULL);

	/* for now we only have one cluster/node, make sure we see it
	 * in the heartbeat universe */
	if (!o2hb_check_local_node_heartbeating()) {
		rc = -EINVAL;
		goto out;
	}

	priv = kzalloc(sizeof(struct o2dlm_private), GFP_KERNEL);
	if (!priv) {
		rc = -ENOMEM;
		goto out_free;
	}

	/* This just fills the structure in.  It is safe to pass conn. */
	dlm_setup_eviction_cb(&priv->op_eviction_cb, o2dlm_eviction_cb,
			      conn);

	conn->cc_private = priv;

	/* used by the dlm code to make message headers unique, each
	 * node in this domain must agree on this. */
	dlm_key = crc32_le(0, conn->cc_name, conn->cc_namelen);
	fs_version.pv_major = conn->cc_version.pv_major;
	fs_version.pv_minor = conn->cc_version.pv_minor;

	dlm = dlm_register_domain(conn->cc_name, dlm_key, &fs_version);
	if (IS_ERR(dlm)) {
		rc = PTR_ERR(dlm);
		mlog_errno(rc);
		goto out_free;
	}

	conn->cc_version.pv_major = fs_version.pv_major;
	conn->cc_version.pv_minor = fs_version.pv_minor;
	conn->cc_lockspace = dlm;

	dlm_register_eviction_cb(dlm, &priv->op_eviction_cb);

out_free:
	if (rc && conn->cc_private)
		kfree(conn->cc_private);

out:
	return rc;
}

static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn)
{
	struct dlm_ctxt *dlm = conn->cc_lockspace;
	struct o2dlm_private *priv = conn->cc_private;

	dlm_unregister_eviction_cb(&priv->op_eviction_cb);
	conn->cc_private = NULL;
	kfree(priv);

	dlm_unregister_domain(dlm);
	conn->cc_lockspace = NULL;

	return 0;
}

static int o2cb_cluster_this_node(unsigned int *node)
{
	int node_num;

	node_num = o2nm_this_node();
	if (node_num == O2NM_INVALID_NODE_NUM)
		return -ENOENT;

	if (node_num >= O2NM_MAX_NODES)
		return -EOVERFLOW;

	*node = node_num;
	return 0;
}

static struct ocfs2_stack_operations o2cb_stack_ops = {
	.connect	= o2cb_cluster_connect,
	.disconnect	= o2cb_cluster_disconnect,
	.this_node	= o2cb_cluster_this_node,
	.dlm_lock	= o2cb_dlm_lock,
	.dlm_unlock	= o2cb_dlm_unlock,
	.lock_status	= o2cb_dlm_lock_status,
	.lvb_valid	= o2cb_dlm_lvb_valid,
	.lock_lvb	= o2cb_dlm_lvb,
	.dump_lksb	= o2cb_dump_lksb,
};

static struct ocfs2_stack_plugin o2cb_stack = {
	.sp_name	= "o2cb",
	.sp_ops		= &o2cb_stack_ops,
	.sp_owner	= THIS_MODULE,
};

static int __init o2cb_stack_init(void)
{
	return ocfs2_stack_glue_register(&o2cb_stack);
}

static void __exit o2cb_stack_exit(void)
{
	ocfs2_stack_glue_unregister(&o2cb_stack);
}

MODULE_AUTHOR("Oracle");
MODULE_DESCRIPTION("ocfs2 driver for the classic o2cb stack");
MODULE_LICENSE("GPL");
module_init(o2cb_stack_init);
module_exit(o2cb_stack_exit);