FS-Cache: Limit the number of I/O error reports for a cache
[deliverable/linux.git] / fs / fscache / internal.h
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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
1bccf513 20 * - cookie->stores_lock
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21 * - 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
0e04d4ce 31/*
348ca102 32 * cache.c
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33 */
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
955d0091 40/*
348ca102 41 * cookie.c
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42 */
43extern struct kmem_cache *fscache_cookie_jar;
44
45extern void fscache_cookie_init_once(void *);
46extern void __fscache_cookie_put(struct fscache_cookie *);
47
a6891645 48/*
348ca102 49 * fsdef.c
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50 */
51extern struct fscache_cookie fscache_fsdef_index;
52extern struct fscache_cookie_def fscache_fsdef_netfs_def;
53
7394daa8 54/*
348ca102 55 * histogram.c
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56 */
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
06b3db1b 78/*
348ca102 79 * main.c
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80 */
81extern unsigned fscache_defer_lookup;
82extern unsigned fscache_defer_create;
83extern unsigned fscache_debug;
84extern struct kobject *fscache_root;
8b8edefa 85extern struct workqueue_struct *fscache_object_wq;
8af7c124 86extern struct workqueue_struct *fscache_op_wq;
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87DECLARE_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}
06b3db1b 93
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94extern int fscache_wait_bit(void *);
95extern int fscache_wait_bit_interruptible(void *);
96
36c95590 97/*
348ca102 98 * object.c
36c95590 99 */
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100extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
101
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102extern void fscache_withdrawing_object(struct fscache_cache *,
103 struct fscache_object *);
104extern void fscache_enqueue_object(struct fscache_object *);
105
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106/*
107 * 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
36c95590 117/*
348ca102 118 * operation.c
36c95590 119 */
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120extern int fscache_submit_exclusive_op(struct fscache_object *,
121 struct fscache_operation *);
122extern int fscache_submit_op(struct fscache_object *,
123 struct fscache_operation *);
5753c441 124extern int fscache_cancel_op(struct fscache_operation *);
ef778e7a 125extern void fscache_cancel_all_ops(struct fscache_object *);
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126extern void fscache_abort_object(struct fscache_object *);
127extern void fscache_start_operations(struct fscache_object *);
128extern void fscache_operation_gc(struct work_struct *);
36c95590 129
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130/*
131 * page.c
132 */
133extern void fscache_invalidate_writes(struct fscache_cookie *);
134
7394daa8 135/*
348ca102 136 * proc.c
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137 */
138#ifdef CONFIG_PROC_FS
139extern int __init fscache_proc_init(void);
140extern void fscache_proc_cleanup(void);
141#else
142#define fscache_proc_init() (0)
143#define fscache_proc_cleanup() do {} while (0)
144#endif
145
146/*
348ca102 147 * stats.c
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148 */
149#ifdef CONFIG_FSCACHE_STATS
150extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
151extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
152
153extern atomic_t fscache_n_op_pend;
154extern atomic_t fscache_n_op_run;
155extern atomic_t fscache_n_op_enqueue;
156extern atomic_t fscache_n_op_deferred_release;
157extern atomic_t fscache_n_op_release;
158extern atomic_t fscache_n_op_gc;
5753c441 159extern atomic_t fscache_n_op_cancelled;
e3d4d28b 160extern atomic_t fscache_n_op_rejected;
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161
162extern atomic_t fscache_n_attr_changed;
163extern atomic_t fscache_n_attr_changed_ok;
164extern atomic_t fscache_n_attr_changed_nobufs;
165extern atomic_t fscache_n_attr_changed_nomem;
166extern atomic_t fscache_n_attr_changed_calls;
167
168extern atomic_t fscache_n_allocs;
169extern atomic_t fscache_n_allocs_ok;
170extern atomic_t fscache_n_allocs_wait;
171extern atomic_t fscache_n_allocs_nobufs;
5753c441 172extern atomic_t fscache_n_allocs_intr;
60d543ca 173extern atomic_t fscache_n_allocs_object_dead;
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174extern atomic_t fscache_n_alloc_ops;
175extern atomic_t fscache_n_alloc_op_waits;
176
177extern atomic_t fscache_n_retrievals;
178extern atomic_t fscache_n_retrievals_ok;
179extern atomic_t fscache_n_retrievals_wait;
180extern atomic_t fscache_n_retrievals_nodata;
181extern atomic_t fscache_n_retrievals_nobufs;
182extern atomic_t fscache_n_retrievals_intr;
183extern atomic_t fscache_n_retrievals_nomem;
60d543ca 184extern atomic_t fscache_n_retrievals_object_dead;
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185extern atomic_t fscache_n_retrieval_ops;
186extern atomic_t fscache_n_retrieval_op_waits;
187
188extern atomic_t fscache_n_stores;
189extern atomic_t fscache_n_stores_ok;
190extern atomic_t fscache_n_stores_again;
191extern atomic_t fscache_n_stores_nobufs;
192extern atomic_t fscache_n_stores_oom;
193extern atomic_t fscache_n_store_ops;
194extern atomic_t fscache_n_store_calls;
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195extern atomic_t fscache_n_store_pages;
196extern atomic_t fscache_n_store_radix_deletes;
197extern atomic_t fscache_n_store_pages_over_limit;
7394daa8 198
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199extern atomic_t fscache_n_store_vmscan_not_storing;
200extern atomic_t fscache_n_store_vmscan_gone;
201extern atomic_t fscache_n_store_vmscan_busy;
202extern atomic_t fscache_n_store_vmscan_cancelled;
203
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204extern atomic_t fscache_n_marks;
205extern atomic_t fscache_n_uncaches;
206
207extern atomic_t fscache_n_acquires;
208extern atomic_t fscache_n_acquires_null;
209extern atomic_t fscache_n_acquires_no_cache;
210extern atomic_t fscache_n_acquires_ok;
211extern atomic_t fscache_n_acquires_nobufs;
212extern atomic_t fscache_n_acquires_oom;
213
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214extern atomic_t fscache_n_invalidates;
215extern atomic_t fscache_n_invalidates_run;
216
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217extern atomic_t fscache_n_updates;
218extern atomic_t fscache_n_updates_null;
219extern atomic_t fscache_n_updates_run;
220
221extern atomic_t fscache_n_relinquishes;
222extern atomic_t fscache_n_relinquishes_null;
223extern atomic_t fscache_n_relinquishes_waitcrt;
2175bb06 224extern atomic_t fscache_n_relinquishes_retire;
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225
226extern atomic_t fscache_n_cookie_index;
227extern atomic_t fscache_n_cookie_data;
228extern atomic_t fscache_n_cookie_special;
229
230extern atomic_t fscache_n_object_alloc;
231extern atomic_t fscache_n_object_no_alloc;
232extern atomic_t fscache_n_object_lookups;
233extern atomic_t fscache_n_object_lookups_negative;
234extern atomic_t fscache_n_object_lookups_positive;
fee096de 235extern atomic_t fscache_n_object_lookups_timed_out;
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236extern atomic_t fscache_n_object_created;
237extern atomic_t fscache_n_object_avail;
238extern atomic_t fscache_n_object_dead;
239
240extern atomic_t fscache_n_checkaux_none;
241extern atomic_t fscache_n_checkaux_okay;
242extern atomic_t fscache_n_checkaux_update;
243extern atomic_t fscache_n_checkaux_obsolete;
244
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245extern atomic_t fscache_n_cop_alloc_object;
246extern atomic_t fscache_n_cop_lookup_object;
247extern atomic_t fscache_n_cop_lookup_complete;
248extern atomic_t fscache_n_cop_grab_object;
ef778e7a 249extern atomic_t fscache_n_cop_invalidate_object;
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250extern atomic_t fscache_n_cop_update_object;
251extern atomic_t fscache_n_cop_drop_object;
252extern atomic_t fscache_n_cop_put_object;
253extern atomic_t fscache_n_cop_sync_cache;
254extern atomic_t fscache_n_cop_attr_changed;
255extern atomic_t fscache_n_cop_read_or_alloc_page;
256extern atomic_t fscache_n_cop_read_or_alloc_pages;
257extern atomic_t fscache_n_cop_allocate_page;
258extern atomic_t fscache_n_cop_allocate_pages;
259extern atomic_t fscache_n_cop_write_page;
260extern atomic_t fscache_n_cop_uncache_page;
261extern atomic_t fscache_n_cop_dissociate_pages;
262
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263static inline void fscache_stat(atomic_t *stat)
264{
265 atomic_inc(stat);
266}
267
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268static inline void fscache_stat_d(atomic_t *stat)
269{
270 atomic_dec(stat);
271}
272
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273#define __fscache_stat(stat) (stat)
274
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275extern const struct file_operations fscache_stats_fops;
276#else
277
60d543ca 278#define __fscache_stat(stat) (NULL)
7394daa8 279#define fscache_stat(stat) do {} while (0)
4fa9f4ed 280#define fscache_stat_d(stat) do {} while (0)
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281#endif
282
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283/*
284 * raise an event on an object
285 * - if the event is not masked for that object, then the object is
286 * queued for attention by the thread pool.
287 */
288static inline void fscache_raise_event(struct fscache_object *object,
289 unsigned event)
290{
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291 if (!test_and_set_bit(event, &object->events) &&
292 test_bit(event, &object->event_mask))
293 fscache_enqueue_object(object);
294}
295
296/*
297 * drop a reference to a cookie
298 */
299static inline void fscache_cookie_put(struct fscache_cookie *cookie)
300{
301 BUG_ON(atomic_read(&cookie->usage) <= 0);
302 if (atomic_dec_and_test(&cookie->usage))
303 __fscache_cookie_put(cookie);
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304}
305
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306/*
307 * get an extra reference to a netfs retrieval context
308 */
309static inline
310void *fscache_get_context(struct fscache_cookie *cookie, void *context)
311{
312 if (cookie->def->get_context)
313 cookie->def->get_context(cookie->netfs_data, context);
314 return context;
315}
316
317/*
318 * release a reference to a netfs retrieval context
319 */
320static inline
321void fscache_put_context(struct fscache_cookie *cookie, void *context)
322{
323 if (cookie->def->put_context)
324 cookie->def->put_context(cookie->netfs_data, context);
325}
326
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327/*****************************************************************************/
328/*
329 * debug tracing
330 */
331#define dbgprintk(FMT, ...) \
332 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
333
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334#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
335#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
336#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
337
12fdff3f 338#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
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339
340#ifdef __KDEBUG
341#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
342#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
343#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
344
345#elif defined(CONFIG_FSCACHE_DEBUG)
346#define _enter(FMT, ...) \
347do { \
348 if (__do_kdebug(ENTER)) \
349 kenter(FMT, ##__VA_ARGS__); \
350} while (0)
351
352#define _leave(FMT, ...) \
353do { \
354 if (__do_kdebug(LEAVE)) \
355 kleave(FMT, ##__VA_ARGS__); \
356} while (0)
357
358#define _debug(FMT, ...) \
359do { \
360 if (__do_kdebug(DEBUG)) \
361 kdebug(FMT, ##__VA_ARGS__); \
362} while (0)
363
364#else
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365#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
366#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
367#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
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368#endif
369
370/*
371 * determine whether a particular optional debugging point should be logged
372 * - we need to go through three steps to persuade cpp to correctly join the
373 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
374 */
375#define ____do_kdebug(LEVEL, POINT) \
376 unlikely((fscache_debug & \
377 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
378#define ___do_kdebug(LEVEL, POINT) \
379 ____do_kdebug(LEVEL, POINT)
380#define __do_kdebug(POINT) \
381 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
382
383#define FSCACHE_DEBUG_CACHE 0
384#define FSCACHE_DEBUG_COOKIE 1
385#define FSCACHE_DEBUG_PAGE 2
386#define FSCACHE_DEBUG_OPERATION 3
387
388#define FSCACHE_POINT_ENTER 1
389#define FSCACHE_POINT_LEAVE 2
390#define FSCACHE_POINT_DEBUG 4
391
392#ifndef FSCACHE_DEBUG_LEVEL
393#define FSCACHE_DEBUG_LEVEL CACHE
394#endif
395
396/*
397 * assertions
398 */
399#if 1 /* defined(__KDEBUGALL) */
400
401#define ASSERT(X) \
402do { \
403 if (unlikely(!(X))) { \
404 printk(KERN_ERR "\n"); \
405 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
406 BUG(); \
407 } \
408} while (0)
409
410#define ASSERTCMP(X, OP, Y) \
411do { \
412 if (unlikely(!((X) OP (Y)))) { \
413 printk(KERN_ERR "\n"); \
414 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
415 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
416 (unsigned long)(X), (unsigned long)(Y)); \
417 BUG(); \
418 } \
419} while (0)
420
421#define ASSERTIF(C, X) \
422do { \
423 if (unlikely((C) && !(X))) { \
424 printk(KERN_ERR "\n"); \
425 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
426 BUG(); \
427 } \
428} while (0)
429
430#define ASSERTIFCMP(C, X, OP, Y) \
431do { \
432 if (unlikely((C) && !((X) OP (Y)))) { \
433 printk(KERN_ERR "\n"); \
434 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
435 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
436 (unsigned long)(X), (unsigned long)(Y)); \
437 BUG(); \
438 } \
439} while (0)
440
441#else
442
443#define ASSERT(X) do {} while (0)
444#define ASSERTCMP(X, OP, Y) do {} while (0)
445#define ASSERTIF(C, X) do {} while (0)
446#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
447
448#endif /* assert or not */
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