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1/* 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 * - cookie->stores_lock
21 * - fscache_thread_lock
22 *
23 */
24
25#ifdef pr_fmt
26#undef pr_fmt
27#endif
28
29#define pr_fmt(fmt) "FS-Cache: " fmt
30
31#include <linux/fscache-cache.h>
32#include <linux/sched.h>
33
34#define FSCACHE_MIN_THREADS 4
35#define FSCACHE_MAX_THREADS 32
36
37/*
38 * cache.c
39 */
40extern struct list_head fscache_cache_list;
41extern struct rw_semaphore fscache_addremove_sem;
42
43extern struct fscache_cache *fscache_select_cache_for_object(
44 struct fscache_cookie *);
45
46/*
47 * cookie.c
48 */
49extern struct kmem_cache *fscache_cookie_jar;
50
51extern void fscache_cookie_init_once(void *);
52extern void __fscache_cookie_put(struct fscache_cookie *);
53
54/*
55 * fsdef.c
56 */
57extern struct fscache_cookie fscache_fsdef_index;
58extern struct fscache_cookie_def fscache_fsdef_netfs_def;
59
60/*
61 * histogram.c
62 */
63#ifdef CONFIG_FSCACHE_HISTOGRAM
64extern atomic_t fscache_obj_instantiate_histogram[HZ];
65extern atomic_t fscache_objs_histogram[HZ];
66extern atomic_t fscache_ops_histogram[HZ];
67extern atomic_t fscache_retrieval_delay_histogram[HZ];
68extern atomic_t fscache_retrieval_histogram[HZ];
69
70static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
71{
72 unsigned long jif = jiffies - start_jif;
73 if (jif >= HZ)
74 jif = HZ - 1;
75 atomic_inc(&histogram[jif]);
76}
77
78extern const struct file_operations fscache_histogram_fops;
79
80#else
81#define fscache_hist(hist, start_jif) do {} while (0)
82#endif
83
84/*
85 * main.c
86 */
87extern unsigned fscache_defer_lookup;
88extern unsigned fscache_defer_create;
89extern unsigned fscache_debug;
90extern struct kobject *fscache_root;
91extern struct workqueue_struct *fscache_object_wq;
92extern struct workqueue_struct *fscache_op_wq;
93DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
94
95static inline bool fscache_object_congested(void)
96{
97 return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
98}
99
100extern int fscache_wait_atomic_t(atomic_t *);
101
102/*
103 * object.c
104 */
105extern void fscache_enqueue_object(struct fscache_object *);
106
107/*
108 * object-list.c
109 */
110#ifdef CONFIG_FSCACHE_OBJECT_LIST
111extern const struct file_operations fscache_objlist_fops;
112
113extern void fscache_objlist_add(struct fscache_object *);
114extern void fscache_objlist_remove(struct fscache_object *);
115#else
116#define fscache_objlist_add(object) do {} while(0)
117#define fscache_objlist_remove(object) do {} while(0)
118#endif
119
120/*
121 * operation.c
122 */
123extern int fscache_submit_exclusive_op(struct fscache_object *,
124 struct fscache_operation *);
125extern int fscache_submit_op(struct fscache_object *,
126 struct fscache_operation *);
127extern int fscache_cancel_op(struct fscache_operation *, bool);
128extern void fscache_cancel_all_ops(struct fscache_object *);
129extern void fscache_abort_object(struct fscache_object *);
130extern void fscache_start_operations(struct fscache_object *);
131extern void fscache_operation_gc(struct work_struct *);
132
133/*
134 * page.c
135 */
136extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
137extern int fscache_wait_for_operation_activation(struct fscache_object *,
138 struct fscache_operation *,
139 atomic_t *,
140 atomic_t *);
141extern void fscache_invalidate_writes(struct fscache_cookie *);
142
143/*
144 * proc.c
145 */
146#ifdef CONFIG_PROC_FS
147extern int __init fscache_proc_init(void);
148extern void fscache_proc_cleanup(void);
149#else
150#define fscache_proc_init() (0)
151#define fscache_proc_cleanup() do {} while (0)
152#endif
153
154/*
155 * stats.c
156 */
157#ifdef CONFIG_FSCACHE_STATS
158extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
159extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
160
161extern atomic_t fscache_n_op_pend;
162extern atomic_t fscache_n_op_run;
163extern atomic_t fscache_n_op_enqueue;
164extern atomic_t fscache_n_op_deferred_release;
165extern atomic_t fscache_n_op_initialised;
166extern atomic_t fscache_n_op_release;
167extern atomic_t fscache_n_op_gc;
168extern atomic_t fscache_n_op_cancelled;
169extern atomic_t fscache_n_op_rejected;
170
171extern atomic_t fscache_n_attr_changed;
172extern atomic_t fscache_n_attr_changed_ok;
173extern atomic_t fscache_n_attr_changed_nobufs;
174extern atomic_t fscache_n_attr_changed_nomem;
175extern atomic_t fscache_n_attr_changed_calls;
176
177extern atomic_t fscache_n_allocs;
178extern atomic_t fscache_n_allocs_ok;
179extern atomic_t fscache_n_allocs_wait;
180extern atomic_t fscache_n_allocs_nobufs;
181extern atomic_t fscache_n_allocs_intr;
182extern atomic_t fscache_n_allocs_object_dead;
183extern atomic_t fscache_n_alloc_ops;
184extern atomic_t fscache_n_alloc_op_waits;
185
186extern atomic_t fscache_n_retrievals;
187extern atomic_t fscache_n_retrievals_ok;
188extern atomic_t fscache_n_retrievals_wait;
189extern atomic_t fscache_n_retrievals_nodata;
190extern atomic_t fscache_n_retrievals_nobufs;
191extern atomic_t fscache_n_retrievals_intr;
192extern atomic_t fscache_n_retrievals_nomem;
193extern atomic_t fscache_n_retrievals_object_dead;
194extern atomic_t fscache_n_retrieval_ops;
195extern atomic_t fscache_n_retrieval_op_waits;
196
197extern atomic_t fscache_n_stores;
198extern atomic_t fscache_n_stores_ok;
199extern atomic_t fscache_n_stores_again;
200extern atomic_t fscache_n_stores_nobufs;
201extern atomic_t fscache_n_stores_oom;
202extern atomic_t fscache_n_store_ops;
203extern atomic_t fscache_n_store_calls;
204extern atomic_t fscache_n_store_pages;
205extern atomic_t fscache_n_store_radix_deletes;
206extern atomic_t fscache_n_store_pages_over_limit;
207
208extern atomic_t fscache_n_store_vmscan_not_storing;
209extern atomic_t fscache_n_store_vmscan_gone;
210extern atomic_t fscache_n_store_vmscan_busy;
211extern atomic_t fscache_n_store_vmscan_cancelled;
212extern atomic_t fscache_n_store_vmscan_wait;
213
214extern atomic_t fscache_n_marks;
215extern atomic_t fscache_n_uncaches;
216
217extern atomic_t fscache_n_acquires;
218extern atomic_t fscache_n_acquires_null;
219extern atomic_t fscache_n_acquires_no_cache;
220extern atomic_t fscache_n_acquires_ok;
221extern atomic_t fscache_n_acquires_nobufs;
222extern atomic_t fscache_n_acquires_oom;
223
224extern atomic_t fscache_n_invalidates;
225extern atomic_t fscache_n_invalidates_run;
226
227extern atomic_t fscache_n_updates;
228extern atomic_t fscache_n_updates_null;
229extern atomic_t fscache_n_updates_run;
230
231extern atomic_t fscache_n_relinquishes;
232extern atomic_t fscache_n_relinquishes_null;
233extern atomic_t fscache_n_relinquishes_waitcrt;
234extern atomic_t fscache_n_relinquishes_retire;
235
236extern atomic_t fscache_n_cookie_index;
237extern atomic_t fscache_n_cookie_data;
238extern atomic_t fscache_n_cookie_special;
239
240extern atomic_t fscache_n_object_alloc;
241extern atomic_t fscache_n_object_no_alloc;
242extern atomic_t fscache_n_object_lookups;
243extern atomic_t fscache_n_object_lookups_negative;
244extern atomic_t fscache_n_object_lookups_positive;
245extern atomic_t fscache_n_object_lookups_timed_out;
246extern atomic_t fscache_n_object_created;
247extern atomic_t fscache_n_object_avail;
248extern atomic_t fscache_n_object_dead;
249
250extern atomic_t fscache_n_checkaux_none;
251extern atomic_t fscache_n_checkaux_okay;
252extern atomic_t fscache_n_checkaux_update;
253extern atomic_t fscache_n_checkaux_obsolete;
254
255extern atomic_t fscache_n_cop_alloc_object;
256extern atomic_t fscache_n_cop_lookup_object;
257extern atomic_t fscache_n_cop_lookup_complete;
258extern atomic_t fscache_n_cop_grab_object;
259extern atomic_t fscache_n_cop_invalidate_object;
260extern atomic_t fscache_n_cop_update_object;
261extern atomic_t fscache_n_cop_drop_object;
262extern atomic_t fscache_n_cop_put_object;
263extern atomic_t fscache_n_cop_sync_cache;
264extern atomic_t fscache_n_cop_attr_changed;
265extern atomic_t fscache_n_cop_read_or_alloc_page;
266extern atomic_t fscache_n_cop_read_or_alloc_pages;
267extern atomic_t fscache_n_cop_allocate_page;
268extern atomic_t fscache_n_cop_allocate_pages;
269extern atomic_t fscache_n_cop_write_page;
270extern atomic_t fscache_n_cop_uncache_page;
271extern atomic_t fscache_n_cop_dissociate_pages;
272
273extern atomic_t fscache_n_cache_no_space_reject;
274extern atomic_t fscache_n_cache_stale_objects;
275extern atomic_t fscache_n_cache_retired_objects;
276extern atomic_t fscache_n_cache_culled_objects;
277
278static inline void fscache_stat(atomic_t *stat)
279{
280 atomic_inc(stat);
281}
282
283static inline void fscache_stat_d(atomic_t *stat)
284{
285 atomic_dec(stat);
286}
287
288#define __fscache_stat(stat) (stat)
289
290extern const struct file_operations fscache_stats_fops;
291#else
292
293#define __fscache_stat(stat) (NULL)
294#define fscache_stat(stat) do {} while (0)
295#define fscache_stat_d(stat) do {} while (0)
296#endif
297
298/*
299 * raise an event on an object
300 * - if the event is not masked for that object, then the object is
301 * queued for attention by the thread pool.
302 */
303static inline void fscache_raise_event(struct fscache_object *object,
304 unsigned event)
305{
306 BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
307#if 0
308 printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
309 object->debug_id, object->event_mask, (1 << event));
310#endif
311 if (!test_and_set_bit(event, &object->events) &&
312 test_bit(event, &object->event_mask))
313 fscache_enqueue_object(object);
314}
315
316/*
317 * drop a reference to a cookie
318 */
319static inline void fscache_cookie_put(struct fscache_cookie *cookie)
320{
321 BUG_ON(atomic_read(&cookie->usage) <= 0);
322 if (atomic_dec_and_test(&cookie->usage))
323 __fscache_cookie_put(cookie);
324}
325
326/*
327 * get an extra reference to a netfs retrieval context
328 */
329static inline
330void *fscache_get_context(struct fscache_cookie *cookie, void *context)
331{
332 if (cookie->def->get_context)
333 cookie->def->get_context(cookie->netfs_data, context);
334 return context;
335}
336
337/*
338 * release a reference to a netfs retrieval context
339 */
340static inline
341void fscache_put_context(struct fscache_cookie *cookie, void *context)
342{
343 if (cookie->def->put_context)
344 cookie->def->put_context(cookie->netfs_data, context);
345}
346
347/*****************************************************************************/
348/*
349 * debug tracing
350 */
351#define dbgprintk(FMT, ...) \
352 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
353
354#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
355#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
356#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
357
358#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
359
360#ifdef __KDEBUG
361#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
362#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
363#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
364
365#elif defined(CONFIG_FSCACHE_DEBUG)
366#define _enter(FMT, ...) \
367do { \
368 if (__do_kdebug(ENTER)) \
369 kenter(FMT, ##__VA_ARGS__); \
370} while (0)
371
372#define _leave(FMT, ...) \
373do { \
374 if (__do_kdebug(LEAVE)) \
375 kleave(FMT, ##__VA_ARGS__); \
376} while (0)
377
378#define _debug(FMT, ...) \
379do { \
380 if (__do_kdebug(DEBUG)) \
381 kdebug(FMT, ##__VA_ARGS__); \
382} while (0)
383
384#else
385#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
386#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
387#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
388#endif
389
390/*
391 * determine whether a particular optional debugging point should be logged
392 * - we need to go through three steps to persuade cpp to correctly join the
393 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
394 */
395#define ____do_kdebug(LEVEL, POINT) \
396 unlikely((fscache_debug & \
397 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
398#define ___do_kdebug(LEVEL, POINT) \
399 ____do_kdebug(LEVEL, POINT)
400#define __do_kdebug(POINT) \
401 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
402
403#define FSCACHE_DEBUG_CACHE 0
404#define FSCACHE_DEBUG_COOKIE 1
405#define FSCACHE_DEBUG_PAGE 2
406#define FSCACHE_DEBUG_OPERATION 3
407
408#define FSCACHE_POINT_ENTER 1
409#define FSCACHE_POINT_LEAVE 2
410#define FSCACHE_POINT_DEBUG 4
411
412#ifndef FSCACHE_DEBUG_LEVEL
413#define FSCACHE_DEBUG_LEVEL CACHE
414#endif
415
416/*
417 * assertions
418 */
419#if 1 /* defined(__KDEBUGALL) */
420
421#define ASSERT(X) \
422do { \
423 if (unlikely(!(X))) { \
424 pr_err("\n"); \
425 pr_err("Assertion failed\n"); \
426 BUG(); \
427 } \
428} while (0)
429
430#define ASSERTCMP(X, OP, Y) \
431do { \
432 if (unlikely(!((X) OP (Y)))) { \
433 pr_err("\n"); \
434 pr_err("Assertion failed\n"); \
435 pr_err("%lx " #OP " %lx is false\n", \
436 (unsigned long)(X), (unsigned long)(Y)); \
437 BUG(); \
438 } \
439} while (0)
440
441#define ASSERTIF(C, X) \
442do { \
443 if (unlikely((C) && !(X))) { \
444 pr_err("\n"); \
445 pr_err("Assertion failed\n"); \
446 BUG(); \
447 } \
448} while (0)
449
450#define ASSERTIFCMP(C, X, OP, Y) \
451do { \
452 if (unlikely((C) && !((X) OP (Y)))) { \
453 pr_err("\n"); \
454 pr_err("Assertion failed\n"); \
455 pr_err("%lx " #OP " %lx is false\n", \
456 (unsigned long)(X), (unsigned long)(Y)); \
457 BUG(); \
458 } \
459} while (0)
460
461#else
462
463#define ASSERT(X) do {} while (0)
464#define ASSERTCMP(X, OP, Y) do {} while (0)
465#define ASSERTIF(C, X) do {} while (0)
466#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
467
468#endif /* assert or not */