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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 Howells955d00912009-04-03 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;
Tejun Heo8b8edef2010-07-20 22:09:01 +020085extern struct workqueue_struct *fscache_object_wq;
Tejun Heo8af7c122010-07-20 22:09:01 +020086extern struct workqueue_struct *fscache_op_wq;
Tejun Heo8b8edef2010-07-20 22:09:01 +020087DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
88
89static inline bool fscache_object_congested(void)
90{
91 return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
92}
David Howells06b3db12009-04-03 16:42:36 +010093
David Howells2868cbe2009-04-03 16:42:38 +010094extern int fscache_wait_bit(void *);
95extern int fscache_wait_bit_interruptible(void *);
96
David Howells7394daa2009-04-03 16:42:37 +010097/*
David Howells348ca102009-05-27 15:46:50 +010098 * object.c
David Howells36c95592009-04-03 16:42:38 +010099 */
David Howells4fbf4292009-11-19 18:11:04 +0000100extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
101
David Howells36c95592009-04-03 16:42:38 +0100102extern void fscache_withdrawing_object(struct fscache_cache *,
103 struct fscache_object *);
104extern void fscache_enqueue_object(struct fscache_object *);
105
106/*
David Howells4fbf4292009-11-19 18:11:04 +0000107 * object-list.c
108 */
109#ifdef CONFIG_FSCACHE_OBJECT_LIST
110extern const struct file_operations fscache_objlist_fops;
111
112extern void fscache_objlist_add(struct fscache_object *);
113#else
114#define fscache_objlist_add(object) do {} while(0)
115#endif
116
117/*
David Howells348ca102009-05-27 15:46:50 +0100118 * operation.c
David Howells36c95592009-04-03 16:42:38 +0100119 */
David Howells952efe72009-04-03 16:42:39 +0100120extern int fscache_submit_exclusive_op(struct fscache_object *,
121 struct fscache_operation *);
122extern int fscache_submit_op(struct fscache_object *,
123 struct fscache_operation *);
David Howells5753c442009-11-19 18:11:19 +0000124extern int fscache_cancel_op(struct fscache_operation *);
David Howells952efe72009-04-03 16:42:39 +0100125extern void fscache_abort_object(struct fscache_object *);
126extern void fscache_start_operations(struct fscache_object *);
127extern void fscache_operation_gc(struct work_struct *);
David Howells36c95592009-04-03 16:42:38 +0100128
129/*
David Howells348ca102009-05-27 15:46:50 +0100130 * proc.c
David Howells7394daa2009-04-03 16:42:37 +0100131 */
132#ifdef CONFIG_PROC_FS
133extern int __init fscache_proc_init(void);
134extern void fscache_proc_cleanup(void);
135#else
136#define fscache_proc_init() (0)
137#define fscache_proc_cleanup() do {} while (0)
138#endif
139
140/*
David Howells348ca102009-05-27 15:46:50 +0100141 * stats.c
David Howells7394daa2009-04-03 16:42:37 +0100142 */
143#ifdef CONFIG_FSCACHE_STATS
144extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
145extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
146
147extern atomic_t fscache_n_op_pend;
148extern atomic_t fscache_n_op_run;
149extern atomic_t fscache_n_op_enqueue;
150extern atomic_t fscache_n_op_deferred_release;
151extern atomic_t fscache_n_op_release;
152extern atomic_t fscache_n_op_gc;
David Howells5753c442009-11-19 18:11:19 +0000153extern atomic_t fscache_n_op_cancelled;
David Howellse3d4d282009-11-19 18:11:32 +0000154extern atomic_t fscache_n_op_rejected;
David Howells7394daa2009-04-03 16:42:37 +0100155
156extern atomic_t fscache_n_attr_changed;
157extern atomic_t fscache_n_attr_changed_ok;
158extern atomic_t fscache_n_attr_changed_nobufs;
159extern atomic_t fscache_n_attr_changed_nomem;
160extern atomic_t fscache_n_attr_changed_calls;
161
162extern atomic_t fscache_n_allocs;
163extern atomic_t fscache_n_allocs_ok;
164extern atomic_t fscache_n_allocs_wait;
165extern atomic_t fscache_n_allocs_nobufs;
David Howells5753c442009-11-19 18:11:19 +0000166extern atomic_t fscache_n_allocs_intr;
David Howells60d543c2009-11-19 18:11:45 +0000167extern atomic_t fscache_n_allocs_object_dead;
David Howells7394daa2009-04-03 16:42:37 +0100168extern atomic_t fscache_n_alloc_ops;
169extern atomic_t fscache_n_alloc_op_waits;
170
171extern atomic_t fscache_n_retrievals;
172extern atomic_t fscache_n_retrievals_ok;
173extern atomic_t fscache_n_retrievals_wait;
174extern atomic_t fscache_n_retrievals_nodata;
175extern atomic_t fscache_n_retrievals_nobufs;
176extern atomic_t fscache_n_retrievals_intr;
177extern atomic_t fscache_n_retrievals_nomem;
David Howells60d543c2009-11-19 18:11:45 +0000178extern atomic_t fscache_n_retrievals_object_dead;
David Howells7394daa2009-04-03 16:42:37 +0100179extern atomic_t fscache_n_retrieval_ops;
180extern atomic_t fscache_n_retrieval_op_waits;
181
182extern atomic_t fscache_n_stores;
183extern atomic_t fscache_n_stores_ok;
184extern atomic_t fscache_n_stores_again;
185extern atomic_t fscache_n_stores_nobufs;
186extern atomic_t fscache_n_stores_oom;
187extern atomic_t fscache_n_store_ops;
188extern atomic_t fscache_n_store_calls;
David Howells1bccf512009-11-19 18:11:25 +0000189extern atomic_t fscache_n_store_pages;
190extern atomic_t fscache_n_store_radix_deletes;
191extern atomic_t fscache_n_store_pages_over_limit;
David Howells7394daa2009-04-03 16:42:37 +0100192
David Howells201a1542009-11-19 18:11:35 +0000193extern atomic_t fscache_n_store_vmscan_not_storing;
194extern atomic_t fscache_n_store_vmscan_gone;
195extern atomic_t fscache_n_store_vmscan_busy;
196extern atomic_t fscache_n_store_vmscan_cancelled;
197
David Howells7394daa2009-04-03 16:42:37 +0100198extern atomic_t fscache_n_marks;
199extern atomic_t fscache_n_uncaches;
200
201extern atomic_t fscache_n_acquires;
202extern atomic_t fscache_n_acquires_null;
203extern atomic_t fscache_n_acquires_no_cache;
204extern atomic_t fscache_n_acquires_ok;
205extern atomic_t fscache_n_acquires_nobufs;
206extern atomic_t fscache_n_acquires_oom;
207
208extern atomic_t fscache_n_updates;
209extern atomic_t fscache_n_updates_null;
210extern atomic_t fscache_n_updates_run;
211
212extern atomic_t fscache_n_relinquishes;
213extern atomic_t fscache_n_relinquishes_null;
214extern atomic_t fscache_n_relinquishes_waitcrt;
David Howells2175bb02009-11-19 18:11:38 +0000215extern atomic_t fscache_n_relinquishes_retire;
David Howells7394daa2009-04-03 16:42:37 +0100216
217extern atomic_t fscache_n_cookie_index;
218extern atomic_t fscache_n_cookie_data;
219extern atomic_t fscache_n_cookie_special;
220
221extern atomic_t fscache_n_object_alloc;
222extern atomic_t fscache_n_object_no_alloc;
223extern atomic_t fscache_n_object_lookups;
224extern atomic_t fscache_n_object_lookups_negative;
225extern atomic_t fscache_n_object_lookups_positive;
David Howellsfee096d2009-11-19 18:12:05 +0000226extern atomic_t fscache_n_object_lookups_timed_out;
David Howells7394daa2009-04-03 16:42:37 +0100227extern atomic_t fscache_n_object_created;
228extern atomic_t fscache_n_object_avail;
229extern atomic_t fscache_n_object_dead;
230
231extern atomic_t fscache_n_checkaux_none;
232extern atomic_t fscache_n_checkaux_okay;
233extern atomic_t fscache_n_checkaux_update;
234extern atomic_t fscache_n_checkaux_obsolete;
235
David Howells52bd75f2009-11-19 18:11:08 +0000236extern atomic_t fscache_n_cop_alloc_object;
237extern atomic_t fscache_n_cop_lookup_object;
238extern atomic_t fscache_n_cop_lookup_complete;
239extern atomic_t fscache_n_cop_grab_object;
240extern atomic_t fscache_n_cop_update_object;
241extern atomic_t fscache_n_cop_drop_object;
242extern atomic_t fscache_n_cop_put_object;
243extern atomic_t fscache_n_cop_sync_cache;
244extern atomic_t fscache_n_cop_attr_changed;
245extern atomic_t fscache_n_cop_read_or_alloc_page;
246extern atomic_t fscache_n_cop_read_or_alloc_pages;
247extern atomic_t fscache_n_cop_allocate_page;
248extern atomic_t fscache_n_cop_allocate_pages;
249extern atomic_t fscache_n_cop_write_page;
250extern atomic_t fscache_n_cop_uncache_page;
251extern atomic_t fscache_n_cop_dissociate_pages;
252
David Howells7394daa2009-04-03 16:42:37 +0100253static inline void fscache_stat(atomic_t *stat)
254{
255 atomic_inc(stat);
256}
257
David Howells52bd75f2009-11-19 18:11:08 +0000258static inline void fscache_stat_d(atomic_t *stat)
259{
260 atomic_dec(stat);
261}
262
David Howells60d543c2009-11-19 18:11:45 +0000263#define __fscache_stat(stat) (stat)
264
David Howells7394daa2009-04-03 16:42:37 +0100265extern const struct file_operations fscache_stats_fops;
266#else
267
David Howells60d543c2009-11-19 18:11:45 +0000268#define __fscache_stat(stat) (NULL)
David Howells7394daa2009-04-03 16:42:37 +0100269#define fscache_stat(stat) do {} while (0)
David Howells4fa9f4e2009-11-20 21:50:44 +0000270#define fscache_stat_d(stat) do {} while (0)
David Howells7394daa2009-04-03 16:42:37 +0100271#endif
272
David Howells0e04d4c2009-04-03 16:42:37 +0100273/*
274 * raise an event on an object
275 * - if the event is not masked for that object, then the object is
276 * queued for attention by the thread pool.
277 */
278static inline void fscache_raise_event(struct fscache_object *object,
279 unsigned event)
280{
David Howells36c95592009-04-03 16:42:38 +0100281 if (!test_and_set_bit(event, &object->events) &&
282 test_bit(event, &object->event_mask))
283 fscache_enqueue_object(object);
284}
285
286/*
287 * drop a reference to a cookie
288 */
289static inline void fscache_cookie_put(struct fscache_cookie *cookie)
290{
291 BUG_ON(atomic_read(&cookie->usage) <= 0);
292 if (atomic_dec_and_test(&cookie->usage))
293 __fscache_cookie_put(cookie);
David Howells0e04d4c2009-04-03 16:42:37 +0100294}
295
David Howellsb5108822009-04-03 16:42:39 +0100296/*
297 * get an extra reference to a netfs retrieval context
298 */
299static inline
300void *fscache_get_context(struct fscache_cookie *cookie, void *context)
301{
302 if (cookie->def->get_context)
303 cookie->def->get_context(cookie->netfs_data, context);
304 return context;
305}
306
307/*
308 * release a reference to a netfs retrieval context
309 */
310static inline
311void fscache_put_context(struct fscache_cookie *cookie, void *context)
312{
313 if (cookie->def->put_context)
314 cookie->def->put_context(cookie->netfs_data, context);
315}
316
David Howells06b3db12009-04-03 16:42:36 +0100317/*****************************************************************************/
318/*
319 * debug tracing
320 */
321#define dbgprintk(FMT, ...) \
322 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
323
David Howells06b3db12009-04-03 16:42:36 +0100324#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
325#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
326#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
327
David Howells12fdff32010-08-12 16:54:57 +0100328#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
David Howells06b3db12009-04-03 16:42:36 +0100329
330#ifdef __KDEBUG
331#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
332#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
333#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
334
335#elif defined(CONFIG_FSCACHE_DEBUG)
336#define _enter(FMT, ...) \
337do { \
338 if (__do_kdebug(ENTER)) \
339 kenter(FMT, ##__VA_ARGS__); \
340} while (0)
341
342#define _leave(FMT, ...) \
343do { \
344 if (__do_kdebug(LEAVE)) \
345 kleave(FMT, ##__VA_ARGS__); \
346} while (0)
347
348#define _debug(FMT, ...) \
349do { \
350 if (__do_kdebug(DEBUG)) \
351 kdebug(FMT, ##__VA_ARGS__); \
352} while (0)
353
354#else
David Howells12fdff32010-08-12 16:54:57 +0100355#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
356#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
357#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
David Howells06b3db12009-04-03 16:42:36 +0100358#endif
359
360/*
361 * determine whether a particular optional debugging point should be logged
362 * - we need to go through three steps to persuade cpp to correctly join the
363 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
364 */
365#define ____do_kdebug(LEVEL, POINT) \
366 unlikely((fscache_debug & \
367 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
368#define ___do_kdebug(LEVEL, POINT) \
369 ____do_kdebug(LEVEL, POINT)
370#define __do_kdebug(POINT) \
371 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
372
373#define FSCACHE_DEBUG_CACHE 0
374#define FSCACHE_DEBUG_COOKIE 1
375#define FSCACHE_DEBUG_PAGE 2
376#define FSCACHE_DEBUG_OPERATION 3
377
378#define FSCACHE_POINT_ENTER 1
379#define FSCACHE_POINT_LEAVE 2
380#define FSCACHE_POINT_DEBUG 4
381
382#ifndef FSCACHE_DEBUG_LEVEL
383#define FSCACHE_DEBUG_LEVEL CACHE
384#endif
385
386/*
387 * assertions
388 */
389#if 1 /* defined(__KDEBUGALL) */
390
391#define ASSERT(X) \
392do { \
393 if (unlikely(!(X))) { \
394 printk(KERN_ERR "\n"); \
395 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
396 BUG(); \
397 } \
398} while (0)
399
400#define ASSERTCMP(X, OP, Y) \
401do { \
402 if (unlikely(!((X) OP (Y)))) { \
403 printk(KERN_ERR "\n"); \
404 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
405 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
406 (unsigned long)(X), (unsigned long)(Y)); \
407 BUG(); \
408 } \
409} while (0)
410
411#define ASSERTIF(C, X) \
412do { \
413 if (unlikely((C) && !(X))) { \
414 printk(KERN_ERR "\n"); \
415 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
416 BUG(); \
417 } \
418} while (0)
419
420#define ASSERTIFCMP(C, X, OP, Y) \
421do { \
422 if (unlikely((C) && !((X) OP (Y)))) { \
423 printk(KERN_ERR "\n"); \
424 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
425 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
426 (unsigned long)(X), (unsigned long)(Y)); \
427 BUG(); \
428 } \
429} while (0)
430
431#else
432
433#define ASSERT(X) do {} while (0)
434#define ASSERTCMP(X, OP, Y) do {} while (0)
435#define ASSERTIF(C, X) do {} while (0)
436#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
437
438#endif /* assert or not */