tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#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/*
32 * cache.c
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
40/*
41 * cookie.c
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
48/*
49 * fsdef.c
50 */
51extern struct fscache_cookie fscache_fsdef_index;
52extern struct fscache_cookie_def fscache_fsdef_netfs_def;
53
54/*
55 * histogram.c
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
78/*
79 * main.c
80 */
81extern unsigned fscache_defer_lookup;
82extern unsigned fscache_defer_create;
83extern unsigned fscache_debug;
84extern struct kobject *fscache_root;
85
86extern int fscache_wait_bit(void *);
87extern int fscache_wait_bit_interruptible(void *);
88
89/*
90 * object.c
91 */
92extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
93
94extern void fscache_withdrawing_object(struct fscache_cache *,
95 struct fscache_object *);
96extern void fscache_enqueue_object(struct fscache_object *);
97
98/*
99 * 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/*
110 * operation.c
111 */
112extern int fscache_submit_exclusive_op(struct fscache_object *,
113 struct fscache_operation *);
114extern int fscache_submit_op(struct fscache_object *,
115 struct fscache_operation *);
116extern int fscache_cancel_op(struct fscache_operation *);
117extern void fscache_abort_object(struct fscache_object *);
118extern void fscache_start_operations(struct fscache_object *);
119extern void fscache_operation_gc(struct work_struct *);
120
121/*
122 * proc.c
123 */
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/*
133 * stats.c
134 */
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;
145extern atomic_t fscache_n_op_cancelled;
146extern atomic_t fscache_n_op_rejected;
147
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;
158extern atomic_t fscache_n_allocs_intr;
159extern atomic_t fscache_n_allocs_object_dead;
160extern 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;
170extern atomic_t fscache_n_retrievals_object_dead;
171extern 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;
181extern atomic_t fscache_n_store_pages;
182extern atomic_t fscache_n_store_radix_deletes;
183extern atomic_t fscache_n_store_pages_over_limit;
184
185extern 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
190extern 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;
207extern atomic_t fscache_n_relinquishes_retire;
208
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;
218extern atomic_t fscache_n_object_lookups_timed_out;
219extern 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
228extern 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
245static inline void fscache_stat(atomic_t *stat)
246{
247 atomic_inc(stat);
248}
249
250static inline void fscache_stat_d(atomic_t *stat)
251{
252 atomic_dec(stat);
253}
254
255#define __fscache_stat(stat) (stat)
256
257extern const struct file_operations fscache_stats_fops;
258#else
259
260#define __fscache_stat(stat) (NULL)
261#define fscache_stat(stat) do {} while (0)
262#define fscache_stat_d(stat) do {} while (0)
263#endif
264
265/*
266 * raise an event on an object
267 * - if the event is not masked for that object, then the object is
268 * queued for attention by the thread pool.
269 */
270static inline void fscache_raise_event(struct fscache_object *object,
271 unsigned event)
272{
273 if (!test_and_set_bit(event, &object->events) &&
274 test_bit(event, &object->event_mask))
275 fscache_enqueue_object(object);
276}
277
278/*
279 * drop a reference to a cookie
280 */
281static inline void fscache_cookie_put(struct fscache_cookie *cookie)
282{
283 BUG_ON(atomic_read(&cookie->usage) <= 0);
284 if (atomic_dec_and_test(&cookie->usage))
285 __fscache_cookie_put(cookie);
286}
287
288/*
289 * get an extra reference to a netfs retrieval context
290 */
291static inline
292void *fscache_get_context(struct fscache_cookie *cookie, void *context)
293{
294 if (cookie->def->get_context)
295 cookie->def->get_context(cookie->netfs_data, context);
296 return context;
297}
298
299/*
300 * release a reference to a netfs retrieval context
301 */
302static inline
303void fscache_put_context(struct fscache_cookie *cookie, void *context)
304{
305 if (cookie->def->put_context)
306 cookie->def->put_context(cookie->netfs_data, context);
307}
308
309/*****************************************************************************/
310/*
311 * debug tracing
312 */
313#define dbgprintk(FMT, ...) \
314 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
315
316/* make sure we maintain the format strings, even when debugging is disabled */
317static inline __attribute__((format(printf, 1, 2)))
318void _dbprintk(const char *fmt, ...)
319{
320}
321
322#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
323#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
324#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
325
326#define kjournal(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
327
328#ifdef __KDEBUG
329#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
330#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
331#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
332
333#elif defined(CONFIG_FSCACHE_DEBUG)
334#define _enter(FMT, ...) \
335do { \
336 if (__do_kdebug(ENTER)) \
337 kenter(FMT, ##__VA_ARGS__); \
338} while (0)
339
340#define _leave(FMT, ...) \
341do { \
342 if (__do_kdebug(LEAVE)) \
343 kleave(FMT, ##__VA_ARGS__); \
344} while (0)
345
346#define _debug(FMT, ...) \
347do { \
348 if (__do_kdebug(DEBUG)) \
349 kdebug(FMT, ##__VA_ARGS__); \
350} while (0)
351
352#else
353#define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
354#define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
355#define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__)
356#endif
357
358/*
359 * determine whether a particular optional debugging point should be logged
360 * - we need to go through three steps to persuade cpp to correctly join the
361 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
362 */
363#define ____do_kdebug(LEVEL, POINT) \
364 unlikely((fscache_debug & \
365 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
366#define ___do_kdebug(LEVEL, POINT) \
367 ____do_kdebug(LEVEL, POINT)
368#define __do_kdebug(POINT) \
369 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
370
371#define FSCACHE_DEBUG_CACHE 0
372#define FSCACHE_DEBUG_COOKIE 1
373#define FSCACHE_DEBUG_PAGE 2
374#define FSCACHE_DEBUG_OPERATION 3
375
376#define FSCACHE_POINT_ENTER 1
377#define FSCACHE_POINT_LEAVE 2
378#define FSCACHE_POINT_DEBUG 4
379
380#ifndef FSCACHE_DEBUG_LEVEL
381#define FSCACHE_DEBUG_LEVEL CACHE
382#endif
383
384/*
385 * assertions
386 */
387#if 1 /* defined(__KDEBUGALL) */
388
389#define ASSERT(X) \
390do { \
391 if (unlikely(!(X))) { \
392 printk(KERN_ERR "\n"); \
393 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
394 BUG(); \
395 } \
396} while (0)
397
398#define ASSERTCMP(X, OP, Y) \
399do { \
400 if (unlikely(!((X) OP (Y)))) { \
401 printk(KERN_ERR "\n"); \
402 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
403 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
404 (unsigned long)(X), (unsigned long)(Y)); \
405 BUG(); \
406 } \
407} while (0)
408
409#define ASSERTIF(C, X) \
410do { \
411 if (unlikely((C) && !(X))) { \
412 printk(KERN_ERR "\n"); \
413 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
414 BUG(); \
415 } \
416} while (0)
417
418#define ASSERTIFCMP(C, X, OP, Y) \
419do { \
420 if (unlikely((C) && !((X) OP (Y)))) { \
421 printk(KERN_ERR "\n"); \
422 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
423 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
424 (unsigned long)(X), (unsigned long)(Y)); \
425 BUG(); \
426 } \
427} while (0)
428
429#else
430
431#define ASSERT(X) do {} while (0)
432#define ASSERTCMP(X, OP, Y) do {} while (0)
433#define ASSERTIF(C, X) do {} while (0)
434#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
435
436#endif /* assert or not */