blob: 1c341304621fc7b132b0f2fffa91ab283f758779 [file] [log] [blame]
David Howells06b3db12009-04-03 16:42:36 +01001/* Internal definitions for FS-Cache
2 *
3 * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12/*
13 * Lock order, in the order in which multiple locks should be obtained:
14 * - fscache_addremove_sem
15 * - cookie->lock
16 * - cookie->parent->lock
17 * - cache->object_list_lock
18 * - object->lock
19 * - object->parent->lock
20 * - fscache_thread_lock
21 *
22 */
23
24#include <linux/fscache-cache.h>
25#include <linux/sched.h>
26
27#define FSCACHE_MIN_THREADS 4
28#define FSCACHE_MAX_THREADS 32
29
30/*
David Howells348ca102009-05-27 15:46:50 +010031 * cache.c
David Howells0e04d4c2009-04-03 16:42:37 +010032 */
33extern struct list_head fscache_cache_list;
34extern struct rw_semaphore fscache_addremove_sem;
35
36extern struct fscache_cache *fscache_select_cache_for_object(
37 struct fscache_cookie *);
38
39/*
David Howells348ca102009-05-27 15:46:50 +010040 * cookie.c
David Howells955d00912009-04-03 16:42:38 +010041 */
42extern struct kmem_cache *fscache_cookie_jar;
43
44extern void fscache_cookie_init_once(void *);
45extern void __fscache_cookie_put(struct fscache_cookie *);
46
47/*
David Howells348ca102009-05-27 15:46:50 +010048 * fsdef.c
David Howellsa6891642009-04-03 16:42:37 +010049 */
50extern struct fscache_cookie fscache_fsdef_index;
51extern struct fscache_cookie_def fscache_fsdef_netfs_def;
52
53/*
David Howells348ca102009-05-27 15:46:50 +010054 * histogram.c
David Howells7394daa2009-04-03 16:42:37 +010055 */
56#ifdef CONFIG_FSCACHE_HISTOGRAM
57extern atomic_t fscache_obj_instantiate_histogram[HZ];
58extern atomic_t fscache_objs_histogram[HZ];
59extern atomic_t fscache_ops_histogram[HZ];
60extern atomic_t fscache_retrieval_delay_histogram[HZ];
61extern atomic_t fscache_retrieval_histogram[HZ];
62
63static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
64{
65 unsigned long jif = jiffies - start_jif;
66 if (jif >= HZ)
67 jif = HZ - 1;
68 atomic_inc(&histogram[jif]);
69}
70
71extern const struct file_operations fscache_histogram_fops;
72
73#else
74#define fscache_hist(hist, start_jif) do {} while (0)
75#endif
76
77/*
David Howells348ca102009-05-27 15:46:50 +010078 * main.c
David Howells06b3db12009-04-03 16:42:36 +010079 */
80extern unsigned fscache_defer_lookup;
81extern unsigned fscache_defer_create;
82extern unsigned fscache_debug;
83extern struct kobject *fscache_root;
84
David Howells2868cbe2009-04-03 16:42:38 +010085extern int fscache_wait_bit(void *);
86extern int fscache_wait_bit_interruptible(void *);
87
David Howells7394daa2009-04-03 16:42:37 +010088/*
David Howells348ca102009-05-27 15:46:50 +010089 * object.c
David Howells36c95592009-04-03 16:42:38 +010090 */
91extern void fscache_withdrawing_object(struct fscache_cache *,
92 struct fscache_object *);
93extern void fscache_enqueue_object(struct fscache_object *);
94
95/*
David Howells348ca102009-05-27 15:46:50 +010096 * operation.c
David Howells36c95592009-04-03 16:42:38 +010097 */
David Howells952efe72009-04-03 16:42:39 +010098extern int fscache_submit_exclusive_op(struct fscache_object *,
99 struct fscache_operation *);
100extern int fscache_submit_op(struct fscache_object *,
101 struct fscache_operation *);
102extern void fscache_abort_object(struct fscache_object *);
103extern void fscache_start_operations(struct fscache_object *);
104extern void fscache_operation_gc(struct work_struct *);
David Howells36c95592009-04-03 16:42:38 +0100105
106/*
David Howells348ca102009-05-27 15:46:50 +0100107 * proc.c
David Howells7394daa2009-04-03 16:42:37 +0100108 */
109#ifdef CONFIG_PROC_FS
110extern int __init fscache_proc_init(void);
111extern void fscache_proc_cleanup(void);
112#else
113#define fscache_proc_init() (0)
114#define fscache_proc_cleanup() do {} while (0)
115#endif
116
117/*
David Howells348ca102009-05-27 15:46:50 +0100118 * stats.c
David Howells7394daa2009-04-03 16:42:37 +0100119 */
120#ifdef CONFIG_FSCACHE_STATS
121extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
122extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
123
124extern atomic_t fscache_n_op_pend;
125extern atomic_t fscache_n_op_run;
126extern atomic_t fscache_n_op_enqueue;
127extern atomic_t fscache_n_op_deferred_release;
128extern atomic_t fscache_n_op_release;
129extern atomic_t fscache_n_op_gc;
130
131extern atomic_t fscache_n_attr_changed;
132extern atomic_t fscache_n_attr_changed_ok;
133extern atomic_t fscache_n_attr_changed_nobufs;
134extern atomic_t fscache_n_attr_changed_nomem;
135extern atomic_t fscache_n_attr_changed_calls;
136
137extern atomic_t fscache_n_allocs;
138extern atomic_t fscache_n_allocs_ok;
139extern atomic_t fscache_n_allocs_wait;
140extern atomic_t fscache_n_allocs_nobufs;
141extern atomic_t fscache_n_alloc_ops;
142extern atomic_t fscache_n_alloc_op_waits;
143
144extern atomic_t fscache_n_retrievals;
145extern atomic_t fscache_n_retrievals_ok;
146extern atomic_t fscache_n_retrievals_wait;
147extern atomic_t fscache_n_retrievals_nodata;
148extern atomic_t fscache_n_retrievals_nobufs;
149extern atomic_t fscache_n_retrievals_intr;
150extern atomic_t fscache_n_retrievals_nomem;
151extern atomic_t fscache_n_retrieval_ops;
152extern atomic_t fscache_n_retrieval_op_waits;
153
154extern atomic_t fscache_n_stores;
155extern atomic_t fscache_n_stores_ok;
156extern atomic_t fscache_n_stores_again;
157extern atomic_t fscache_n_stores_nobufs;
158extern atomic_t fscache_n_stores_oom;
159extern atomic_t fscache_n_store_ops;
160extern atomic_t fscache_n_store_calls;
161
162extern atomic_t fscache_n_marks;
163extern atomic_t fscache_n_uncaches;
164
165extern atomic_t fscache_n_acquires;
166extern atomic_t fscache_n_acquires_null;
167extern atomic_t fscache_n_acquires_no_cache;
168extern atomic_t fscache_n_acquires_ok;
169extern atomic_t fscache_n_acquires_nobufs;
170extern atomic_t fscache_n_acquires_oom;
171
172extern atomic_t fscache_n_updates;
173extern atomic_t fscache_n_updates_null;
174extern atomic_t fscache_n_updates_run;
175
176extern atomic_t fscache_n_relinquishes;
177extern atomic_t fscache_n_relinquishes_null;
178extern atomic_t fscache_n_relinquishes_waitcrt;
179
180extern atomic_t fscache_n_cookie_index;
181extern atomic_t fscache_n_cookie_data;
182extern atomic_t fscache_n_cookie_special;
183
184extern atomic_t fscache_n_object_alloc;
185extern atomic_t fscache_n_object_no_alloc;
186extern atomic_t fscache_n_object_lookups;
187extern atomic_t fscache_n_object_lookups_negative;
188extern atomic_t fscache_n_object_lookups_positive;
189extern atomic_t fscache_n_object_created;
190extern atomic_t fscache_n_object_avail;
191extern atomic_t fscache_n_object_dead;
192
193extern atomic_t fscache_n_checkaux_none;
194extern atomic_t fscache_n_checkaux_okay;
195extern atomic_t fscache_n_checkaux_update;
196extern atomic_t fscache_n_checkaux_obsolete;
197
198static inline void fscache_stat(atomic_t *stat)
199{
200 atomic_inc(stat);
201}
202
203extern const struct file_operations fscache_stats_fops;
204#else
205
206#define fscache_stat(stat) do {} while (0)
207#endif
208
David Howells0e04d4c2009-04-03 16:42:37 +0100209/*
210 * raise an event on an object
211 * - if the event is not masked for that object, then the object is
212 * queued for attention by the thread pool.
213 */
214static inline void fscache_raise_event(struct fscache_object *object,
215 unsigned event)
216{
David Howells36c95592009-04-03 16:42:38 +0100217 if (!test_and_set_bit(event, &object->events) &&
218 test_bit(event, &object->event_mask))
219 fscache_enqueue_object(object);
220}
221
222/*
223 * drop a reference to a cookie
224 */
225static inline void fscache_cookie_put(struct fscache_cookie *cookie)
226{
227 BUG_ON(atomic_read(&cookie->usage) <= 0);
228 if (atomic_dec_and_test(&cookie->usage))
229 __fscache_cookie_put(cookie);
David Howells0e04d4c2009-04-03 16:42:37 +0100230}
231
David Howellsb5108822009-04-03 16:42:39 +0100232/*
233 * get an extra reference to a netfs retrieval context
234 */
235static inline
236void *fscache_get_context(struct fscache_cookie *cookie, void *context)
237{
238 if (cookie->def->get_context)
239 cookie->def->get_context(cookie->netfs_data, context);
240 return context;
241}
242
243/*
244 * release a reference to a netfs retrieval context
245 */
246static inline
247void fscache_put_context(struct fscache_cookie *cookie, void *context)
248{
249 if (cookie->def->put_context)
250 cookie->def->put_context(cookie->netfs_data, context);
251}
252
David Howells06b3db12009-04-03 16:42:36 +0100253/*****************************************************************************/
254/*
255 * debug tracing
256 */
257#define dbgprintk(FMT, ...) \
258 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
259
260/* make sure we maintain the format strings, even when debugging is disabled */
261static inline __attribute__((format(printf, 1, 2)))
262void _dbprintk(const char *fmt, ...)
263{
264}
265
266#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
267#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
268#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
269
270#define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
271
272#ifdef __KDEBUG
273#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
274#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
275#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
276
277#elif defined(CONFIG_FSCACHE_DEBUG)
278#define _enter(FMT, ...) \
279do { \
280 if (__do_kdebug(ENTER)) \
281 kenter(FMT, ##__VA_ARGS__); \
282} while (0)
283
284#define _leave(FMT, ...) \
285do { \
286 if (__do_kdebug(LEAVE)) \
287 kleave(FMT, ##__VA_ARGS__); \
288} while (0)
289
290#define _debug(FMT, ...) \
291do { \
292 if (__do_kdebug(DEBUG)) \
293 kdebug(FMT, ##__VA_ARGS__); \
294} while (0)
295
296#else
297#define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
298#define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
299#define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
300#endif
301
302/*
303 * determine whether a particular optional debugging point should be logged
304 * - we need to go through three steps to persuade cpp to correctly join the
305 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
306 */
307#define ____do_kdebug(LEVEL, POINT) \
308 unlikely((fscache_debug & \
309 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
310#define ___do_kdebug(LEVEL, POINT) \
311 ____do_kdebug(LEVEL, POINT)
312#define __do_kdebug(POINT) \
313 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
314
315#define FSCACHE_DEBUG_CACHE 0
316#define FSCACHE_DEBUG_COOKIE 1
317#define FSCACHE_DEBUG_PAGE 2
318#define FSCACHE_DEBUG_OPERATION 3
319
320#define FSCACHE_POINT_ENTER 1
321#define FSCACHE_POINT_LEAVE 2
322#define FSCACHE_POINT_DEBUG 4
323
324#ifndef FSCACHE_DEBUG_LEVEL
325#define FSCACHE_DEBUG_LEVEL CACHE
326#endif
327
328/*
329 * assertions
330 */
331#if 1 /* defined(__KDEBUGALL) */
332
333#define ASSERT(X) \
334do { \
335 if (unlikely(!(X))) { \
336 printk(KERN_ERR "\n"); \
337 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
338 BUG(); \
339 } \
340} while (0)
341
342#define ASSERTCMP(X, OP, Y) \
343do { \
344 if (unlikely(!((X) OP (Y)))) { \
345 printk(KERN_ERR "\n"); \
346 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
347 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
348 (unsigned long)(X), (unsigned long)(Y)); \
349 BUG(); \
350 } \
351} while (0)
352
353#define ASSERTIF(C, X) \
354do { \
355 if (unlikely((C) && !(X))) { \
356 printk(KERN_ERR "\n"); \
357 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
358 BUG(); \
359 } \
360} while (0)
361
362#define ASSERTIFCMP(C, X, OP, Y) \
363do { \
364 if (unlikely((C) && !((X) OP (Y)))) { \
365 printk(KERN_ERR "\n"); \
366 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
367 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
368 (unsigned long)(X), (unsigned long)(Y)); \
369 BUG(); \
370 } \
371} while (0)
372
373#else
374
375#define ASSERT(X) do {} while (0)
376#define ASSERTCMP(X, OP, Y) do {} while (0)
377#define ASSERTIF(C, X) do {} while (0)
378#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
379
380#endif /* assert or not */