aboutsummaryrefslogtreecommitdiffstats
path: root/fs/fscache/internal.h
blob: fe02973a9516881c57b2da5351274bed043968f8 (plain) (blame)
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
/* Internal definitions for FS-Cache
 *
 * Copyright (C) 2004-2007 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 License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

/*
 * Lock order, in the order in which multiple locks should be obtained:
 * - fscache_addremove_sem
 * - cookie->lock
 * - cookie->parent->lock
 * - cache->object_list_lock
 * - object->lock
 * - object->parent->lock
 * - fscache_thread_lock
 *
 */

#include <linux/fscache-cache.h>
#include <linux/sched.h>

#define FSCACHE_MIN_THREADS	4
#define FSCACHE_MAX_THREADS	32

/*
 * cache.c
 */
extern struct list_head fscache_cache_list;
extern struct rw_semaphore fscache_addremove_sem;

extern struct fscache_cache *fscache_select_cache_for_object(
	struct fscache_cookie *);

/*
 * cookie.c
 */
extern struct kmem_cache *fscache_cookie_jar;

extern void fscache_cookie_init_once(void *);
extern void __fscache_cookie_put(struct fscache_cookie *);

/*
 * fsdef.c
 */
extern struct fscache_cookie fscache_fsdef_index;
extern struct fscache_cookie_def fscache_fsdef_netfs_def;

/*
 * histogram.c
 */
#ifdef CONFIG_FSCACHE_HISTOGRAM
extern atomic_t fscache_obj_instantiate_histogram[HZ];
extern atomic_t fscache_objs_histogram[HZ];
extern atomic_t fscache_ops_histogram[HZ];
extern atomic_t fscache_retrieval_delay_histogram[HZ];
extern atomic_t fscache_retrieval_histogram[HZ];

static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
{
	unsigned long jif = jiffies - start_jif;
	if (jif >= HZ)
		jif = HZ - 1;
	atomic_inc(&histogram[jif]);
}

extern const struct file_operations fscache_histogram_fops;

#else
#define fscache_hist(hist, start_jif) do {} while (0)
#endif

/*
 * main.c
 */
extern unsigned fscache_defer_lookup;
extern unsigned fscache_defer_create;
extern unsigned fscache_debug;
extern struct kobject *fscache_root;

extern int fscache_wait_bit(void *);
extern int fscache_wait_bit_interruptible(void *);

/*
 * object.c
 */
extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];

extern void fscache_withdrawing_object(struct fscache_cache *,
				       struct fscache_object *);
extern void fscache_enqueue_object(struct fscache_object *);

/*
 * object-list.c
 */
#ifdef CONFIG_FSCACHE_OBJECT_LIST
extern const struct file_operations fscache_objlist_fops;

extern void fscache_objlist_add(struct fscache_object *);
#else
#define fscache_objlist_add(object) do {} while(0)
#endif

/*
 * operation.c
 */
extern int fscache_submit_exclusive_op(struct fscache_object *,
				       struct fscache_operation *);
extern int fscache_submit_op(struct fscache_object *,
			     struct fscache_operation *);
extern void fscache_abort_object(struct fscache_object *);
extern void fscache_start_operations(struct fscache_object *);
extern void fscache_operation_gc(struct work_struct *);

/*
 * proc.c
 */
#ifdef CONFIG_PROC_FS
extern int __init fscache_proc_init(void);
extern void fscache_proc_cleanup(void);
#else
#define fscache_proc_init()	(0)
#define fscache_proc_cleanup()	do {} while (0)
#endif

/*
 * stats.c
 */
#ifdef CONFIG_FSCACHE_STATS
extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];

extern atomic_t fscache_n_op_pend;
extern atomic_t fscache_n_op_run;
extern atomic_t fscache_n_op_enqueue;
extern atomic_t fscache_n_op_deferred_release;
extern atomic_t fscache_n_op_release;
extern atomic_t fscache_n_op_gc;

extern atomic_t fscache_n_attr_changed;
extern atomic_t fscache_n_attr_changed_ok;
extern atomic_t fscache_n_attr_changed_nobufs;
extern atomic_t fscache_n_attr_changed_nomem;
extern atomic_t fscache_n_attr_changed_calls;

extern atomic_t fscache_n_allocs;
extern atomic_t fscache_n_allocs_ok;
extern atomic_t fscache_n_allocs_wait;
extern atomic_t fscache_n_allocs_nobufs;
extern atomic_t fscache_n_alloc_ops;
extern atomic_t fscache_n_alloc_op_waits;

extern atomic_t fscache_n_retrievals;
extern atomic_t fscache_n_retrievals_ok;
extern atomic_t fscache_n_retrievals_wait;
extern atomic_t fscache_n_retrievals_nodata;
extern atomic_t fscache_n_retrievals_nobufs;
extern atomic_t fscache_n_retrievals_intr;
extern atomic_t fscache_n_retrievals_nomem;
extern atomic_t fscache_n_retrieval_ops;
extern atomic_t fscache_n_retrieval_op_waits;

extern atomic_t fscache_n_stores;
extern atomic_t fscache_n_stores_ok;
extern atomic_t fscache_n_stores_again;
extern atomic_t fscache_n_stores_nobufs;
extern atomic_t fscache_n_stores_oom;
extern atomic_t fscache_n_store_ops;
extern atomic_t fscache_n_store_calls;

extern atomic_t fscache_n_marks;
extern atomic_t fscache_n_uncaches;

extern atomic_t fscache_n_acquires;
extern atomic_t fscache_n_acquires_null;
extern atomic_t fscache_n_acquires_no_cache;
extern atomic_t fscache_n_acquires_ok;
extern atomic_t fscache_n_acquires_nobufs;
extern atomic_t fscache_n_acquires_oom;

extern atomic_t fscache_n_updates;
extern atomic_t fscache_n_updates_null;
extern atomic_t fscache_n_updates_run;

extern atomic_t fscache_n_relinquishes;
extern atomic_t fscache_n_relinquishes_null;
extern atomic_t fscache_n_relinquishes_waitcrt;

extern atomic_t fscache_n_cookie_index;
extern atomic_t fscache_n_cookie_data;
extern atomic_t fscache_n_cookie_special;

extern atomic_t fscache_n_object_alloc;
extern atomic_t fscache_n_object_no_alloc;
extern atomic_t fscache_n_object_lookups;
extern atomic_t fscache_n_object_lookups_negative;
extern atomic_t fscache_n_object_lookups_positive;
extern atomic_t fscache_n_object_created;
extern atomic_t fscache_n_object_avail;
extern atomic_t fscache_n_object_dead;

extern atomic_t fscache_n_checkaux_none;
extern atomic_t fscache_n_checkaux_okay;
extern atomic_t fscache_n_checkaux_update;
extern atomic_t fscache_n_checkaux_obsolete;

static inline void fscache_stat(atomic_t *stat)
{
	atomic_inc(stat);
}

extern const struct file_operations fscache_stats_fops;
#else

#define fscache_stat(stat) do {} while (0)
#endif

/*
 * raise an event on an object
 * - if the event is not masked for that object, then the object is
 *   queued for attention by the thread pool.
 */
static inline void fscache_raise_event(struct fscache_object *object,
				       unsigned event)
{
	if (!test_and_set_bit(event, &object->events) &&
	    test_bit(event, &object->event_mask))
		fscache_enqueue_object(object);
}

/*
 * drop a reference to a cookie
 */
static inline void fscache_cookie_put(struct fscache_cookie *cookie)
{
	BUG_ON(atomic_read(&cookie->usage) <= 0);
	if (atomic_dec_and_test(&cookie->usage))
		__fscache_cookie_put(cookie);
}

/*
 * get an extra reference to a netfs retrieval context
 */
static inline
void *fscache_get_context(struct fscache_cookie *cookie, void *context)
{
	if (cookie->def->get_context)
		cookie->def->get_context(cookie->netfs_data, context);
	return context;
}

/*
 * release a reference to a netfs retrieval context
 */
static inline
void fscache_put_context(struct fscache_cookie *cookie, void *context)
{
	if (cookie->def->put_context)
		cookie->def->put_context(cookie->netfs_data, context);
}

/*****************************************************************************/
/*
 * debug tracing
 */
#define dbgprintk(FMT, ...) \
	printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)

/* make sure we maintain the format strings, even when debugging is disabled */
static inline __attribute__((format(printf, 1, 2)))
void _dbprintk(const char *fmt, ...)
{
}

#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)

#define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)

#ifdef __KDEBUG
#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)

#elif defined(CONFIG_FSCACHE_DEBUG)
#define _enter(FMT, ...)			\
do {						\
	if (__do_kdebug(ENTER))			\
		kenter(FMT, ##__VA_ARGS__);	\
} while (0)

#define _leave(FMT, ...)			\
do {						\
	if (__do_kdebug(LEAVE))			\
		kleave(FMT, ##__VA_ARGS__);	\
} while (0)

#define _debug(FMT, ...)			\
do {						\
	if (__do_kdebug(DEBUG))			\
		kdebug(FMT, ##__VA_ARGS__);	\
} while (0)

#else
#define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
#define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
#endif

/*
 * determine whether a particular optional debugging point should be logged
 * - we need to go through three steps to persuade cpp to correctly join the
 *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
 */
#define ____do_kdebug(LEVEL, POINT) \
	unlikely((fscache_debug & \
		  (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
#define ___do_kdebug(LEVEL, POINT) \
	____do_kdebug(LEVEL, POINT)
#define __do_kdebug(POINT) \
	___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)

#define FSCACHE_DEBUG_CACHE	0
#define FSCACHE_DEBUG_COOKIE	1
#define FSCACHE_DEBUG_PAGE	2
#define FSCACHE_DEBUG_OPERATION	3

#define FSCACHE_POINT_ENTER	1
#define FSCACHE_POINT_LEAVE	2
#define FSCACHE_POINT_DEBUG	4

#ifndef FSCACHE_DEBUG_LEVEL
#define FSCACHE_DEBUG_LEVEL CACHE
#endif

/*
 * assertions
 */
#if 1 /* defined(__KDEBUGALL) */

#define ASSERT(X)							\
do {									\
	if (unlikely(!(X))) {						\
		printk(KERN_ERR "\n");					\
		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\
		BUG();							\
	}								\
} while (0)

#define ASSERTCMP(X, OP, Y)						\
do {									\
	if (unlikely(!((X) OP (Y)))) {					\
		printk(KERN_ERR "\n");					\
		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\
		printk(KERN_ERR "%lx " #OP " %lx is false\n",		\
		       (unsigned long)(X), (unsigned long)(Y));		\
		BUG();							\
	}								\
} while (0)

#define ASSERTIF(C, X)							\
do {									\
	if (unlikely((C) && !(X))) {					\
		printk(KERN_ERR "\n");					\
		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\
		BUG();							\
	}								\
} while (0)

#define ASSERTIFCMP(C, X, OP, Y)					\
do {									\
	if (unlikely((C) && !((X) OP (Y)))) {				\
		printk(KERN_ERR "\n");					\
		printk(KERN_ERR "FS-Cache: Assertion failed\n");	\
		printk(KERN_ERR "%lx " #OP " %lx is false\n",		\
		       (unsigned long)(X), (unsigned long)(Y));		\
		BUG();							\
	}								\
} while (0)

#else

#define ASSERT(X)			do {} while (0)
#define ASSERTCMP(X, OP, Y)		do {} while (0)
#define ASSERTIF(C, X)			do {} while (0)
#define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)

#endif /* assert or not */