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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
David Howells1bccf512009-11-19 18:11:25 +000020 * - cookie->stores_lock
David Howells06b3db12009-04-03 16:42:36 +010021 * - fscache_thread_lock
22 *
23 */
24
25#include <linux/fscache-cache.h>
26#include <linux/sched.h>
27
28#define FSCACHE_MIN_THREADS 4
29#define FSCACHE_MAX_THREADS 32
30
31/*
David Howells348ca102009-05-27 15:46:50 +010032 * cache.c
David Howells0e04d4c2009-04-03 16:42:37 +010033 */
34extern struct list_head fscache_cache_list;
35extern struct rw_semaphore fscache_addremove_sem;
36
37extern struct fscache_cache *fscache_select_cache_for_object(
38 struct fscache_cookie *);
39
40/*
David Howells348ca102009-05-27 15:46:50 +010041 * cookie.c
David Howells955d0092009-04-03 16:42:38 +010042 */
43extern struct kmem_cache *fscache_cookie_jar;
44
45extern void fscache_cookie_init_once(void *);
46extern void __fscache_cookie_put(struct fscache_cookie *);
47
48/*
David Howells348ca102009-05-27 15:46:50 +010049 * fsdef.c
David Howellsa6891642009-04-03 16:42:37 +010050 */
51extern struct fscache_cookie fscache_fsdef_index;
52extern struct fscache_cookie_def fscache_fsdef_netfs_def;
53
54/*
David Howells348ca102009-05-27 15:46:50 +010055 * histogram.c
David Howells7394daa2009-04-03 16:42:37 +010056 */
57#ifdef CONFIG_FSCACHE_HISTOGRAM
58extern atomic_t fscache_obj_instantiate_histogram[HZ];
59extern atomic_t fscache_objs_histogram[HZ];
60extern atomic_t fscache_ops_histogram[HZ];
61extern atomic_t fscache_retrieval_delay_histogram[HZ];
62extern atomic_t fscache_retrieval_histogram[HZ];
63
64static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
65{
66 unsigned long jif = jiffies - start_jif;
67 if (jif >= HZ)
68 jif = HZ - 1;
69 atomic_inc(&histogram[jif]);
70}
71
72extern const struct file_operations fscache_histogram_fops;
73
74#else
75#define fscache_hist(hist, start_jif) do {} while (0)
76#endif
77
78/*
David Howells348ca102009-05-27 15:46:50 +010079 * main.c
David Howells06b3db12009-04-03 16:42:36 +010080 */
81extern unsigned fscache_defer_lookup;
82extern unsigned fscache_defer_create;
83extern unsigned fscache_debug;
84extern struct kobject *fscache_root;
85
David Howells2868cbe2009-04-03 16:42:38 +010086extern int fscache_wait_bit(void *);
87extern int fscache_wait_bit_interruptible(void *);
88
David Howells7394daa2009-04-03 16:42:37 +010089/*
David Howells348ca102009-05-27 15:46:50 +010090 * object.c
David Howells36c95592009-04-03 16:42:38 +010091 */
David Howells4fbf4292009-11-19 18:11:04 +000092extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
93
David Howells36c95592009-04-03 16:42:38 +010094extern void fscache_withdrawing_object(struct fscache_cache *,
95 struct fscache_object *);
96extern void fscache_enqueue_object(struct fscache_object *);
97
98/*
David Howells4fbf4292009-11-19 18:11:04 +000099 * object-list.c
100 */
101#ifdef CONFIG_FSCACHE_OBJECT_LIST
102extern const struct file_operations fscache_objlist_fops;
103
104extern void fscache_objlist_add(struct fscache_object *);
105#else
106#define fscache_objlist_add(object) do {} while(0)
107#endif
108
109/*
David Howells348ca102009-05-27 15:46:50 +0100110 * operation.c
David Howells36c95592009-04-03 16:42:38 +0100111 */
David Howells952efe72009-04-03 16:42:39 +0100112extern int fscache_submit_exclusive_op(struct fscache_object *,
113 struct fscache_operation *);
114extern int fscache_submit_op(struct fscache_object *,
115 struct fscache_operation *);
David Howells5753c442009-11-19 18:11:19 +0000116extern int fscache_cancel_op(struct fscache_operation *);
David Howells952efe72009-04-03 16:42:39 +0100117extern void fscache_abort_object(struct fscache_object *);
118extern void fscache_start_operations(struct fscache_object *);
119extern void fscache_operation_gc(struct work_struct *);
David Howells36c95592009-04-03 16:42:38 +0100120
121/*
David Howells348ca102009-05-27 15:46:50 +0100122 * proc.c
David Howells7394daa2009-04-03 16:42:37 +0100123 */
124#ifdef CONFIG_PROC_FS
125extern int __init fscache_proc_init(void);
126extern void fscache_proc_cleanup(void);
127#else
128#define fscache_proc_init() (0)
129#define fscache_proc_cleanup() do {} while (0)
130#endif
131
132/*
David Howells348ca102009-05-27 15:46:50 +0100133 * stats.c
David Howells7394daa2009-04-03 16:42:37 +0100134 */
135#ifdef CONFIG_FSCACHE_STATS
136extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
137extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
138
139extern atomic_t fscache_n_op_pend;
140extern atomic_t fscache_n_op_run;
141extern atomic_t fscache_n_op_enqueue;
142extern atomic_t fscache_n_op_deferred_release;
143extern atomic_t fscache_n_op_release;
144extern atomic_t fscache_n_op_gc;
David Howells5753c442009-11-19 18:11:19 +0000145extern atomic_t fscache_n_op_cancelled;
David Howellse3d4d282009-11-19 18:11:32 +0000146extern atomic_t fscache_n_op_rejected;
David Howells7394daa2009-04-03 16:42:37 +0100147
148extern atomic_t fscache_n_attr_changed;
149extern atomic_t fscache_n_attr_changed_ok;
150extern atomic_t fscache_n_attr_changed_nobufs;
151extern atomic_t fscache_n_attr_changed_nomem;
152extern atomic_t fscache_n_attr_changed_calls;
153
154extern atomic_t fscache_n_allocs;
155extern atomic_t fscache_n_allocs_ok;
156extern atomic_t fscache_n_allocs_wait;
157extern atomic_t fscache_n_allocs_nobufs;
David Howells5753c442009-11-19 18:11:19 +0000158extern atomic_t fscache_n_allocs_intr;
David Howells60d543c2009-11-19 18:11:45 +0000159extern atomic_t fscache_n_allocs_object_dead;
David Howells7394daa2009-04-03 16:42:37 +0100160extern atomic_t fscache_n_alloc_ops;
161extern atomic_t fscache_n_alloc_op_waits;
162
163extern atomic_t fscache_n_retrievals;
164extern atomic_t fscache_n_retrievals_ok;
165extern atomic_t fscache_n_retrievals_wait;
166extern atomic_t fscache_n_retrievals_nodata;
167extern atomic_t fscache_n_retrievals_nobufs;
168extern atomic_t fscache_n_retrievals_intr;
169extern atomic_t fscache_n_retrievals_nomem;
David Howells60d543c2009-11-19 18:11:45 +0000170extern atomic_t fscache_n_retrievals_object_dead;
David Howells7394daa2009-04-03 16:42:37 +0100171extern atomic_t fscache_n_retrieval_ops;
172extern atomic_t fscache_n_retrieval_op_waits;
173
174extern atomic_t fscache_n_stores;
175extern atomic_t fscache_n_stores_ok;
176extern atomic_t fscache_n_stores_again;
177extern atomic_t fscache_n_stores_nobufs;
178extern atomic_t fscache_n_stores_oom;
179extern atomic_t fscache_n_store_ops;
180extern atomic_t fscache_n_store_calls;
David Howells1bccf512009-11-19 18:11:25 +0000181extern atomic_t fscache_n_store_pages;
182extern atomic_t fscache_n_store_radix_deletes;
183extern atomic_t fscache_n_store_pages_over_limit;
David Howells7394daa2009-04-03 16:42:37 +0100184
David Howells201a1542009-11-19 18:11:35 +0000185extern atomic_t fscache_n_store_vmscan_not_storing;
186extern atomic_t fscache_n_store_vmscan_gone;
187extern atomic_t fscache_n_store_vmscan_busy;
188extern atomic_t fscache_n_store_vmscan_cancelled;
189
David Howells7394daa2009-04-03 16:42:37 +0100190extern atomic_t fscache_n_marks;
191extern atomic_t fscache_n_uncaches;
192
193extern atomic_t fscache_n_acquires;
194extern atomic_t fscache_n_acquires_null;
195extern atomic_t fscache_n_acquires_no_cache;
196extern atomic_t fscache_n_acquires_ok;
197extern atomic_t fscache_n_acquires_nobufs;
198extern atomic_t fscache_n_acquires_oom;
199
200extern atomic_t fscache_n_updates;
201extern atomic_t fscache_n_updates_null;
202extern atomic_t fscache_n_updates_run;
203
204extern atomic_t fscache_n_relinquishes;
205extern atomic_t fscache_n_relinquishes_null;
206extern atomic_t fscache_n_relinquishes_waitcrt;
David Howells2175bb02009-11-19 18:11:38 +0000207extern atomic_t fscache_n_relinquishes_retire;
David Howells7394daa2009-04-03 16:42:37 +0100208
209extern atomic_t fscache_n_cookie_index;
210extern atomic_t fscache_n_cookie_data;
211extern atomic_t fscache_n_cookie_special;
212
213extern atomic_t fscache_n_object_alloc;
214extern atomic_t fscache_n_object_no_alloc;
215extern atomic_t fscache_n_object_lookups;
216extern atomic_t fscache_n_object_lookups_negative;
217extern atomic_t fscache_n_object_lookups_positive;
David Howellsfee096d2009-11-19 18:12:05 +0000218extern atomic_t fscache_n_object_lookups_timed_out;
David Howells7394daa2009-04-03 16:42:37 +0100219extern atomic_t fscache_n_object_created;
220extern atomic_t fscache_n_object_avail;
221extern atomic_t fscache_n_object_dead;
222
223extern atomic_t fscache_n_checkaux_none;
224extern atomic_t fscache_n_checkaux_okay;
225extern atomic_t fscache_n_checkaux_update;
226extern atomic_t fscache_n_checkaux_obsolete;
227
David Howells52bd75f2009-11-19 18:11:08 +0000228extern atomic_t fscache_n_cop_alloc_object;
229extern atomic_t fscache_n_cop_lookup_object;
230extern atomic_t fscache_n_cop_lookup_complete;
231extern atomic_t fscache_n_cop_grab_object;
232extern atomic_t fscache_n_cop_update_object;
233extern atomic_t fscache_n_cop_drop_object;
234extern atomic_t fscache_n_cop_put_object;
235extern atomic_t fscache_n_cop_sync_cache;
236extern atomic_t fscache_n_cop_attr_changed;
237extern atomic_t fscache_n_cop_read_or_alloc_page;
238extern atomic_t fscache_n_cop_read_or_alloc_pages;
239extern atomic_t fscache_n_cop_allocate_page;
240extern atomic_t fscache_n_cop_allocate_pages;
241extern atomic_t fscache_n_cop_write_page;
242extern atomic_t fscache_n_cop_uncache_page;
243extern atomic_t fscache_n_cop_dissociate_pages;
244
David Howells7394daa2009-04-03 16:42:37 +0100245static inline void fscache_stat(atomic_t *stat)
246{
247 atomic_inc(stat);
248}
249
David Howells52bd75f2009-11-19 18:11:08 +0000250static inline void fscache_stat_d(atomic_t *stat)
251{
252 atomic_dec(stat);
253}
254
David Howells60d543c2009-11-19 18:11:45 +0000255#define __fscache_stat(stat) (stat)
256
David Howells7394daa2009-04-03 16:42:37 +0100257extern const struct file_operations fscache_stats_fops;
258#else
259
David Howells60d543c2009-11-19 18:11:45 +0000260#define __fscache_stat(stat) (NULL)
David Howells7394daa2009-04-03 16:42:37 +0100261#define fscache_stat(stat) do {} while (0)
262#endif
263
David Howells0e04d4c2009-04-03 16:42:37 +0100264/*
265 * raise an event on an object
266 * - if the event is not masked for that object, then the object is
267 * queued for attention by the thread pool.
268 */
269static inline void fscache_raise_event(struct fscache_object *object,
270 unsigned event)
271{
David Howells36c95592009-04-03 16:42:38 +0100272 if (!test_and_set_bit(event, &object->events) &&
273 test_bit(event, &object->event_mask))
274 fscache_enqueue_object(object);
275}
276
277/*
278 * drop a reference to a cookie
279 */
280static inline void fscache_cookie_put(struct fscache_cookie *cookie)
281{
282 BUG_ON(atomic_read(&cookie->usage) <= 0);
283 if (atomic_dec_and_test(&cookie->usage))
284 __fscache_cookie_put(cookie);
David Howells0e04d4c2009-04-03 16:42:37 +0100285}
286
David Howellsb5108822009-04-03 16:42:39 +0100287/*
288 * get an extra reference to a netfs retrieval context
289 */
290static inline
291void *fscache_get_context(struct fscache_cookie *cookie, void *context)
292{
293 if (cookie->def->get_context)
294 cookie->def->get_context(cookie->netfs_data, context);
295 return context;
296}
297
298/*
299 * release a reference to a netfs retrieval context
300 */
301static inline
302void fscache_put_context(struct fscache_cookie *cookie, void *context)
303{
304 if (cookie->def->put_context)
305 cookie->def->put_context(cookie->netfs_data, context);
306}
307
David Howells06b3db12009-04-03 16:42:36 +0100308/*****************************************************************************/
309/*
310 * debug tracing
311 */
312#define dbgprintk(FMT, ...) \
313 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
314
315/* make sure we maintain the format strings, even when debugging is disabled */
316static inline __attribute__((format(printf, 1, 2)))
317void _dbprintk(const char *fmt, ...)
318{
319}
320
321#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
322#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
323#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
324
325#define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
326
327#ifdef __KDEBUG
328#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
329#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
330#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
331
332#elif defined(CONFIG_FSCACHE_DEBUG)
333#define _enter(FMT, ...) \
334do { \
335 if (__do_kdebug(ENTER)) \
336 kenter(FMT, ##__VA_ARGS__); \
337} while (0)
338
339#define _leave(FMT, ...) \
340do { \
341 if (__do_kdebug(LEAVE)) \
342 kleave(FMT, ##__VA_ARGS__); \
343} while (0)
344
345#define _debug(FMT, ...) \
346do { \
347 if (__do_kdebug(DEBUG)) \
348 kdebug(FMT, ##__VA_ARGS__); \
349} while (0)
350
351#else
352#define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
353#define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
354#define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
355#endif
356
357/*
358 * determine whether a particular optional debugging point should be logged
359 * - we need to go through three steps to persuade cpp to correctly join the
360 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
361 */
362#define ____do_kdebug(LEVEL, POINT) \
363 unlikely((fscache_debug & \
364 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
365#define ___do_kdebug(LEVEL, POINT) \
366 ____do_kdebug(LEVEL, POINT)
367#define __do_kdebug(POINT) \
368 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
369
370#define FSCACHE_DEBUG_CACHE 0
371#define FSCACHE_DEBUG_COOKIE 1
372#define FSCACHE_DEBUG_PAGE 2
373#define FSCACHE_DEBUG_OPERATION 3
374
375#define FSCACHE_POINT_ENTER 1
376#define FSCACHE_POINT_LEAVE 2
377#define FSCACHE_POINT_DEBUG 4
378
379#ifndef FSCACHE_DEBUG_LEVEL
380#define FSCACHE_DEBUG_LEVEL CACHE
381#endif
382
383/*
384 * assertions
385 */
386#if 1 /* defined(__KDEBUGALL) */
387
388#define ASSERT(X) \
389do { \
390 if (unlikely(!(X))) { \
391 printk(KERN_ERR "\n"); \
392 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
393 BUG(); \
394 } \
395} while (0)
396
397#define ASSERTCMP(X, OP, Y) \
398do { \
399 if (unlikely(!((X) OP (Y)))) { \
400 printk(KERN_ERR "\n"); \
401 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
402 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
403 (unsigned long)(X), (unsigned long)(Y)); \
404 BUG(); \
405 } \
406} while (0)
407
408#define ASSERTIF(C, X) \
409do { \
410 if (unlikely((C) && !(X))) { \
411 printk(KERN_ERR "\n"); \
412 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
413 BUG(); \
414 } \
415} while (0)
416
417#define ASSERTIFCMP(C, X, OP, Y) \
418do { \
419 if (unlikely((C) && !((X) OP (Y)))) { \
420 printk(KERN_ERR "\n"); \
421 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
422 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
423 (unsigned long)(X), (unsigned long)(Y)); \
424 BUG(); \
425 } \
426} while (0)
427
428#else
429
430#define ASSERT(X) do {} while (0)
431#define ASSERTCMP(X, OP, Y) do {} while (0)
432#define ASSERTIF(C, X) do {} while (0)
433#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
434
435#endif /* assert or not */