aboutsummaryrefslogtreecommitdiff
path: root/fs/fscache/object-list.c
blob: 3221a0c7944e32fbe02c5d8c6c759b5766d6ce69 (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
/* Global fscache object list maintainer and viewer
 *
 * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#define FSCACHE_DEBUG_LEVEL COOKIE
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/key.h>
#include <keys/user-type.h>
#include "internal.h"

static struct rb_root fscache_object_list;
static DEFINE_RWLOCK(fscache_object_list_lock);

struct fscache_objlist_data {
	unsigned long	config;		/* display configuration */
#define FSCACHE_OBJLIST_CONFIG_KEY	0x00000001	/* show object keys */
#define FSCACHE_OBJLIST_CONFIG_AUX	0x00000002	/* show object auxdata */
#define FSCACHE_OBJLIST_CONFIG_COOKIE	0x00000004	/* show objects with cookies */
#define FSCACHE_OBJLIST_CONFIG_NOCOOKIE	0x00000008	/* show objects without cookies */
#define FSCACHE_OBJLIST_CONFIG_BUSY	0x00000010	/* show busy objects */
#define FSCACHE_OBJLIST_CONFIG_IDLE	0x00000020	/* show idle objects */
#define FSCACHE_OBJLIST_CONFIG_PENDWR	0x00000040	/* show objects with pending writes */
#define FSCACHE_OBJLIST_CONFIG_NOPENDWR	0x00000080	/* show objects without pending writes */
#define FSCACHE_OBJLIST_CONFIG_READS	0x00000100	/* show objects with active reads */
#define FSCACHE_OBJLIST_CONFIG_NOREADS	0x00000200	/* show objects without active reads */
#define FSCACHE_OBJLIST_CONFIG_EVENTS	0x00000400	/* show objects with events */
#define FSCACHE_OBJLIST_CONFIG_NOEVENTS	0x00000800	/* show objects without no events */
#define FSCACHE_OBJLIST_CONFIG_WORK	0x00001000	/* show objects with slow work */
#define FSCACHE_OBJLIST_CONFIG_NOWORK	0x00002000	/* show objects without slow work */

	u8		buf[512];	/* key and aux data buffer */
};

/*
 * Add an object to the object list
 * - we use the address of the fscache_object structure as the key into the
 *   tree
 */
void fscache_objlist_add(struct fscache_object *obj)
{
	struct fscache_object *xobj;
	struct rb_node **p = &fscache_object_list.rb_node, *parent = NULL;

	write_lock(&fscache_object_list_lock);

	while (*p) {
		parent = *p;
		xobj = rb_entry(parent, struct fscache_object, objlist_link);

		if (obj < xobj)
			p = &(*p)->rb_left;
		else if (obj > xobj)
			p = &(*p)->rb_right;
		else
			BUG();
	}

	rb_link_node(&obj->objlist_link, parent, p);
	rb_insert_color(&obj->objlist_link, &fscache_object_list);

	write_unlock(&fscache_object_list_lock);
}

/**
 * fscache_object_destroy - Note that a cache object is about to be destroyed
 * @object: The object to be destroyed
 *
 * Note the imminent destruction and deallocation of a cache object record.
 */
void fscache_object_destroy(struct fscache_object *obj)
{
	write_lock(&fscache_object_list_lock);

	BUG_ON(RB_EMPTY_ROOT(&fscache_object_list));
	rb_erase(&obj->objlist_link, &fscache_object_list);

	write_unlock(&fscache_object_list_lock);
}
EXPORT_SYMBOL(fscache_object_destroy);

/*
 * find the object in the tree on or after the specified index
 */
static struct fscache_object *fscache_objlist_lookup(loff_t *_pos)
{
	struct fscache_object *pobj, *obj = NULL, *minobj = NULL;
	struct rb_node *p;
	unsigned long pos;

	if (*_pos >= (unsigned long) ERR_PTR(-ENOENT))
		return NULL;
	pos = *_pos;

	/* banners (can't represent line 0 by pos 0 as that would involve
	 * returning a NULL pointer) */
	if (pos == 0)
		return (struct fscache_object *) ++(*_pos);
	if (pos < 3)
		return (struct fscache_object *)pos;

	pobj = (struct fscache_object *)pos;
	p = fscache_object_list.rb_node;
	while (p) {
		obj = rb_entry(p, struct fscache_object, objlist_link);
		if (pobj < obj) {
			if (!minobj || minobj > obj)
				minobj = obj;
			p = p->rb_left;
		} else if (pobj > obj) {
			p = p->rb_right;
		} else {
			minobj = obj;
			break;
		}
		obj = NULL;
	}

	if (!minobj)
		*_pos = (unsigned long) ERR_PTR(-ENOENT);
	else if (minobj != obj)
		*_pos = (unsigned long) minobj;
	return minobj;
}

/*
 * set up the iterator to start reading from the first line
 */
static void *fscache_objlist_start(struct seq_file *m, loff_t *_pos)
	__acquires(&fscache_object_list_lock)
{
	read_lock(&fscache_object_list_lock);
	return fscache_objlist_lookup(_pos);
}

/*
 * move to the next line
 */
static void *fscache_objlist_next(struct seq_file *m, void *v, loff_t *_pos)
{
	(*_pos)++;
	return fscache_objlist_lookup(_pos);
}

/*
 * clean up after reading
 */
static void fscache_objlist_stop(struct seq_file *m, void *v)
	__releases(&fscache_object_list_lock)
{
	read_unlock(&fscache_object_list_lock);
}

/*
 * display an object
 */
static int fscache_objlist_show(struct seq_file *m, void *v)
{
	struct fscache_objlist_data *data = m->private;
	struct fscache_object *obj = v;
	unsigned long config = data->config;
	uint16_t keylen, auxlen;
	char _type[3], *type;
	bool no_cookie;
	u8 *buf = data->buf, *p;

	if ((unsigned long) v == 1) {
		seq_puts(m, "OBJECT   PARENT   STAT CHLDN OPS OOP IPR EX READS"
			 " EM EV F S"
			 " | NETFS_COOKIE_DEF TY FL NETFS_DATA");
		if (config & (FSCACHE_OBJLIST_CONFIG_KEY |
			      FSCACHE_OBJLIST_CONFIG_AUX))
			seq_puts(m, "       ");
		if (config & FSCACHE_OBJLIST_CONFIG_KEY)
			seq_puts(m, "OBJECT_KEY");
		if ((config & (FSCACHE_OBJLIST_CONFIG_KEY |
			       FSCACHE_OBJLIST_CONFIG_AUX)) ==
		    (FSCACHE_OBJLIST_CONFIG_KEY | FSCACHE_OBJLIST_CONFIG_AUX))
			seq_puts(m, ", ");
		if (config & FSCACHE_OBJLIST_CONFIG_AUX)
			seq_puts(m, "AUX_DATA");
		seq_puts(m, "\n");
		return 0;
	}

	if ((unsigned long) v == 2) {
		seq_puts(m, "======== ======== ==== ===== === === === == ====="
			 " == == = ="
			 " | ================ == == ================");
		if (config & (FSCACHE_OBJLIST_CONFIG_KEY |
			      FSCACHE_OBJLIST_CONFIG_AUX))
			seq_puts(m, " ================");
		seq_puts(m, "\n");
		return 0;
	}

	/* filter out any unwanted objects */
#define FILTER(criterion, _yes, _no)					\
	do {								\
		unsigned long yes = FSCACHE_OBJLIST_CONFIG_##_yes;	\
		unsigned long no = FSCACHE_OBJLIST_CONFIG_##_no;	\
		if (criterion) {					\
			if (!(config & yes))				\
				return 0;				\
		} else {						\
			if (!(config & no))				\
				return 0;				\
		}							\
	} while(0)

	if (~config) {
		FILTER(obj->cookie,
		       COOKIE, NOCOOKIE);
		FILTER(obj->state != FSCACHE_OBJECT_ACTIVE ||
		       obj->n_ops != 0 ||
		       obj->n_obj_ops != 0 ||
		       obj->flags ||
		       !list_empty(&obj->dependents),
		       BUSY, IDLE);
		FILTER(test_bit(FSCACHE_OBJECT_PENDING_WRITE, &obj->flags),
		       PENDWR, NOPENDWR);
		FILTER(atomic_read(&obj->n_reads),
		       READS, NOREADS);
		FILTER(obj->events & obj->event_mask,
		       EVENTS, NOEVENTS);
		FILTER(obj->work.flags & ~(1UL << SLOW_WORK_VERY_SLOW),
		       WORK, NOWORK);
	}

	seq_printf(m,
		   "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1lx | ",
		   obj->debug_id,
		   obj->parent ? obj->parent->debug_id : -1,
		   fscache_object_states_short[obj->state],
		   obj->n_children,
		   obj->n_ops,
		   obj->n_obj_ops,
		   obj->n_in_progress,
		   obj->n_exclusive,
		   atomic_read(&obj->n_reads),
		   obj->event_mask & FSCACHE_OBJECT_EVENTS_MASK,
		   obj->events,
		   obj->flags,
		   obj->work.flags);

	no_cookie = true;
	keylen = auxlen = 0;
	if (obj->cookie) {
		spin_lock(&obj->lock);
		if (obj->cookie) {
			switch (obj->cookie->def->type) {
			case 0:
				type = "IX";
				break;
			case 1:
				type = "DT";
				break;
			default:
				sprintf(_type, "%02u",
					obj->cookie->def->type);
				type = _type;
				break;
			}

			seq_printf(m, "%-16s %s %2lx %16p",
				   obj->cookie->def->name,
				   type,
				   obj->cookie->flags,
				   obj->cookie->netfs_data);

			if (obj->cookie->def->get_key &&
			    config & FSCACHE_OBJLIST_CONFIG_KEY)
				keylen = obj->cookie->def->get_key(
					obj->cookie->netfs_data,
					buf, 400);

			if (obj->cookie->def->get_aux &&
			    config & FSCACHE_OBJLIST_CONFIG_AUX)
				auxlen = obj->cookie->def->get_aux(
					obj->cookie->netfs_data,
					buf + keylen, 512 - keylen);

			no_cookie = false;
		}
		spin_unlock(&obj->lock);

		if (!no_cookie && (keylen > 0 || auxlen > 0)) {
			seq_printf(m, " ");
			for (p = buf; keylen > 0; keylen--)
				seq_printf(m, "%02x", *p++);
			if (auxlen > 0) {
				if (config & FSCACHE_OBJLIST_CONFIG_KEY)
					seq_printf(m, ", ");
				for (; auxlen > 0; auxlen--)
					seq_printf(m, "%02x", *p++);
			}
		}
	}

	if (no_cookie)
		seq_printf(m, "<no_cookie>\n");
	else
		seq_printf(m, "\n");
	return 0;
}

static const struct seq_operations fscache_objlist_ops = {
	.start		= fscache_objlist_start,
	.stop		= fscache_objlist_stop,
	.next		= fscache_objlist_next,
	.show		= fscache_objlist_show,
};

/*
 * get the configuration for filtering the list
 */
static void fscache_objlist_config(struct fscache_objlist_data *data)
{
#ifdef CONFIG_KEYS
	struct user_key_payload *confkey;
	unsigned long config;
	struct key *key;
	const char *buf;
	int len;

	key = request_key(&key_type_user, "fscache:objlist", NULL);
	if (IS_ERR(key))
		goto no_config;

	config = 0;
	rcu_read_lock();

	confkey = key->payload.data;
	buf = confkey->data;

	for (len = confkey->datalen - 1; len >= 0; len--) {
		switch (buf[len]) {
		case 'K': config |= FSCACHE_OBJLIST_CONFIG_KEY;		break;
		case 'A': config |= FSCACHE_OBJLIST_CONFIG_AUX;		break;
		case 'C': config |= FSCACHE_OBJLIST_CONFIG_COOKIE;	break;
		case 'c': config |= FSCACHE_OBJLIST_CONFIG_NOCOOKIE;	break;
		case 'B': config |= FSCACHE_OBJLIST_CONFIG_BUSY;	break;
		case 'b': config |= FSCACHE_OBJLIST_CONFIG_IDLE;	break;
		case 'W': config |= FSCACHE_OBJLIST_CONFIG_PENDWR;	break;
		case 'w': config |= FSCACHE_OBJLIST_CONFIG_NOPENDWR;	break;
		case 'R': config |= FSCACHE_OBJLIST_CONFIG_READS;	break;
		case 'r': config |= FSCACHE_OBJLIST_CONFIG_NOREADS;	break;
		case 'S': config |= FSCACHE_OBJLIST_CONFIG_WORK;	break;
		case 's': config |= FSCACHE_OBJLIST_CONFIG_NOWORK;	break;
		}
	}

	rcu_read_unlock();
	key_put(key);

	if (!(config & (FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE)))
	    config   |= FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE;
	if (!(config & (FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE)))
	    config   |= FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE;
	if (!(config & (FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR)))
	    config   |= FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR;
	if (!(config & (FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS)))
	    config   |= FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS;
	if (!(config & (FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS)))
	    config   |= FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS;
	if (!(config & (FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK)))
	    config   |= FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK;

	data->config = config;
	return;

no_config:
#endif
	data->config = ULONG_MAX;
}

/*
 * open "/proc/fs/fscache/objects" to provide a list of active objects
 * - can be configured by a user-defined key added to the caller's keyrings
 */
static int fscache_objlist_open(struct inode *inode, struct file *file)
{
	struct fscache_objlist_data *data;
	struct seq_file *m;
	int ret;

	ret = seq_open(file, &fscache_objlist_ops);
	if (ret < 0)
		return ret;

	m = file->private_data;

	/* buffer for key extraction */
	data = kmalloc(sizeof(struct fscache_objlist_data), GFP_KERNEL);
	if (!data) {
		seq_release(inode, file);
		return -ENOMEM;
	}

	/* get the configuration key */
	fscache_objlist_config(data);

	m->private = data;
	return 0;
}

/*
 * clean up on close
 */
static int fscache_objlist_release(struct inode *inode, struct file *file)
{
	struct seq_file *m = file->private_data;

	kfree(m->private);
	m->private = NULL;
	return seq_release(inode, file);
}

const struct file_operations fscache_objlist_fops = {
	.owner		= THIS_MODULE,
	.open		= fscache_objlist_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= fscache_objlist_release,
};