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 */
34 extern struct list_head fscache_cache_list;
35 extern struct rw_semaphore fscache_addremove_sem;
36
37 extern struct fscache_cache *fscache_select_cache_for_object(
38 struct fscache_cookie *);
39
40 /*
41 * cookie.c
42 */
43 extern struct kmem_cache *fscache_cookie_jar;
44
45 extern void fscache_cookie_init_once(void *);
46 extern void __fscache_cookie_put(struct fscache_cookie *);
47
48 /*
49 * fsdef.c
50 */
51 extern struct fscache_cookie fscache_fsdef_index;
52 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
53
54 /*
55 * histogram.c
56 */
57 #ifdef CONFIG_FSCACHE_HISTOGRAM
58 extern atomic_t fscache_obj_instantiate_histogram[HZ];
59 extern atomic_t fscache_objs_histogram[HZ];
60 extern atomic_t fscache_ops_histogram[HZ];
61 extern atomic_t fscache_retrieval_delay_histogram[HZ];
62 extern atomic_t fscache_retrieval_histogram[HZ];
63
fscache_hist(atomic_t histogram[],unsigned long start_jif)64 static 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
72 extern 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 */
81 extern unsigned fscache_defer_lookup;
82 extern unsigned fscache_defer_create;
83 extern unsigned fscache_debug;
84 extern struct kobject *fscache_root;
85 extern struct workqueue_struct *fscache_object_wq;
86 extern struct workqueue_struct *fscache_op_wq;
87 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
88
fscache_object_congested(void)89 static inline bool fscache_object_congested(void)
90 {
91 return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
92 }
93
94 extern int fscache_wait_bit(void *);
95 extern int fscache_wait_bit_interruptible(void *);
96
97 /*
98 * object.c
99 */
100 extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
101
102 extern void fscache_withdrawing_object(struct fscache_cache *,
103 struct fscache_object *);
104 extern void fscache_enqueue_object(struct fscache_object *);
105
106 /*
107 * object-list.c
108 */
109 #ifdef CONFIG_FSCACHE_OBJECT_LIST
110 extern const struct file_operations fscache_objlist_fops;
111
112 extern void fscache_objlist_add(struct fscache_object *);
113 #else
114 #define fscache_objlist_add(object) do {} while(0)
115 #endif
116
117 /*
118 * operation.c
119 */
120 extern int fscache_submit_exclusive_op(struct fscache_object *,
121 struct fscache_operation *);
122 extern int fscache_submit_op(struct fscache_object *,
123 struct fscache_operation *);
124 extern int fscache_cancel_op(struct fscache_operation *);
125 extern void fscache_abort_object(struct fscache_object *);
126 extern void fscache_start_operations(struct fscache_object *);
127 extern void fscache_operation_gc(struct work_struct *);
128
129 /*
130 * proc.c
131 */
132 #ifdef CONFIG_PROC_FS
133 extern int __init fscache_proc_init(void);
134 extern 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 /*
141 * stats.c
142 */
143 #ifdef CONFIG_FSCACHE_STATS
144 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
145 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
146
147 extern atomic_t fscache_n_op_pend;
148 extern atomic_t fscache_n_op_run;
149 extern atomic_t fscache_n_op_enqueue;
150 extern atomic_t fscache_n_op_deferred_release;
151 extern atomic_t fscache_n_op_release;
152 extern atomic_t fscache_n_op_gc;
153 extern atomic_t fscache_n_op_cancelled;
154 extern atomic_t fscache_n_op_rejected;
155
156 extern atomic_t fscache_n_attr_changed;
157 extern atomic_t fscache_n_attr_changed_ok;
158 extern atomic_t fscache_n_attr_changed_nobufs;
159 extern atomic_t fscache_n_attr_changed_nomem;
160 extern atomic_t fscache_n_attr_changed_calls;
161
162 extern atomic_t fscache_n_allocs;
163 extern atomic_t fscache_n_allocs_ok;
164 extern atomic_t fscache_n_allocs_wait;
165 extern atomic_t fscache_n_allocs_nobufs;
166 extern atomic_t fscache_n_allocs_intr;
167 extern atomic_t fscache_n_allocs_object_dead;
168 extern atomic_t fscache_n_alloc_ops;
169 extern atomic_t fscache_n_alloc_op_waits;
170
171 extern atomic_t fscache_n_retrievals;
172 extern atomic_t fscache_n_retrievals_ok;
173 extern atomic_t fscache_n_retrievals_wait;
174 extern atomic_t fscache_n_retrievals_nodata;
175 extern atomic_t fscache_n_retrievals_nobufs;
176 extern atomic_t fscache_n_retrievals_intr;
177 extern atomic_t fscache_n_retrievals_nomem;
178 extern atomic_t fscache_n_retrievals_object_dead;
179 extern atomic_t fscache_n_retrieval_ops;
180 extern atomic_t fscache_n_retrieval_op_waits;
181
182 extern atomic_t fscache_n_stores;
183 extern atomic_t fscache_n_stores_ok;
184 extern atomic_t fscache_n_stores_again;
185 extern atomic_t fscache_n_stores_nobufs;
186 extern atomic_t fscache_n_stores_oom;
187 extern atomic_t fscache_n_store_ops;
188 extern atomic_t fscache_n_store_calls;
189 extern atomic_t fscache_n_store_pages;
190 extern atomic_t fscache_n_store_radix_deletes;
191 extern atomic_t fscache_n_store_pages_over_limit;
192
193 extern atomic_t fscache_n_store_vmscan_not_storing;
194 extern atomic_t fscache_n_store_vmscan_gone;
195 extern atomic_t fscache_n_store_vmscan_busy;
196 extern atomic_t fscache_n_store_vmscan_cancelled;
197
198 extern atomic_t fscache_n_marks;
199 extern atomic_t fscache_n_uncaches;
200
201 extern atomic_t fscache_n_acquires;
202 extern atomic_t fscache_n_acquires_null;
203 extern atomic_t fscache_n_acquires_no_cache;
204 extern atomic_t fscache_n_acquires_ok;
205 extern atomic_t fscache_n_acquires_nobufs;
206 extern atomic_t fscache_n_acquires_oom;
207
208 extern atomic_t fscache_n_updates;
209 extern atomic_t fscache_n_updates_null;
210 extern atomic_t fscache_n_updates_run;
211
212 extern atomic_t fscache_n_relinquishes;
213 extern atomic_t fscache_n_relinquishes_null;
214 extern atomic_t fscache_n_relinquishes_waitcrt;
215 extern atomic_t fscache_n_relinquishes_retire;
216
217 extern atomic_t fscache_n_cookie_index;
218 extern atomic_t fscache_n_cookie_data;
219 extern atomic_t fscache_n_cookie_special;
220
221 extern atomic_t fscache_n_object_alloc;
222 extern atomic_t fscache_n_object_no_alloc;
223 extern atomic_t fscache_n_object_lookups;
224 extern atomic_t fscache_n_object_lookups_negative;
225 extern atomic_t fscache_n_object_lookups_positive;
226 extern atomic_t fscache_n_object_lookups_timed_out;
227 extern atomic_t fscache_n_object_created;
228 extern atomic_t fscache_n_object_avail;
229 extern atomic_t fscache_n_object_dead;
230
231 extern atomic_t fscache_n_checkaux_none;
232 extern atomic_t fscache_n_checkaux_okay;
233 extern atomic_t fscache_n_checkaux_update;
234 extern atomic_t fscache_n_checkaux_obsolete;
235
236 extern atomic_t fscache_n_cop_alloc_object;
237 extern atomic_t fscache_n_cop_lookup_object;
238 extern atomic_t fscache_n_cop_lookup_complete;
239 extern atomic_t fscache_n_cop_grab_object;
240 extern atomic_t fscache_n_cop_update_object;
241 extern atomic_t fscache_n_cop_drop_object;
242 extern atomic_t fscache_n_cop_put_object;
243 extern atomic_t fscache_n_cop_sync_cache;
244 extern atomic_t fscache_n_cop_attr_changed;
245 extern atomic_t fscache_n_cop_read_or_alloc_page;
246 extern atomic_t fscache_n_cop_read_or_alloc_pages;
247 extern atomic_t fscache_n_cop_allocate_page;
248 extern atomic_t fscache_n_cop_allocate_pages;
249 extern atomic_t fscache_n_cop_write_page;
250 extern atomic_t fscache_n_cop_uncache_page;
251 extern atomic_t fscache_n_cop_dissociate_pages;
252
fscache_stat(atomic_t * stat)253 static inline void fscache_stat(atomic_t *stat)
254 {
255 atomic_inc(stat);
256 }
257
fscache_stat_d(atomic_t * stat)258 static inline void fscache_stat_d(atomic_t *stat)
259 {
260 atomic_dec(stat);
261 }
262
263 #define __fscache_stat(stat) (stat)
264
265 extern const struct file_operations fscache_stats_fops;
266 #else
267
268 #define __fscache_stat(stat) (NULL)
269 #define fscache_stat(stat) do {} while (0)
270 #define fscache_stat_d(stat) do {} while (0)
271 #endif
272
273 /*
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 */
fscache_raise_event(struct fscache_object * object,unsigned event)278 static inline void fscache_raise_event(struct fscache_object *object,
279 unsigned event)
280 {
281 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 */
fscache_cookie_put(struct fscache_cookie * cookie)289 static 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);
294 }
295
296 /*
297 * get an extra reference to a netfs retrieval context
298 */
299 static inline
fscache_get_context(struct fscache_cookie * cookie,void * context)300 void *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 */
310 static inline
fscache_put_context(struct fscache_cookie * cookie,void * context)311 void 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
317 /*****************************************************************************/
318 /*
319 * debug tracing
320 */
321 #define dbgprintk(FMT, ...) \
322 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
323
324 #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
328 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
329
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, ...) \
337 do { \
338 if (__do_kdebug(ENTER)) \
339 kenter(FMT, ##__VA_ARGS__); \
340 } while (0)
341
342 #define _leave(FMT, ...) \
343 do { \
344 if (__do_kdebug(LEAVE)) \
345 kleave(FMT, ##__VA_ARGS__); \
346 } while (0)
347
348 #define _debug(FMT, ...) \
349 do { \
350 if (__do_kdebug(DEBUG)) \
351 kdebug(FMT, ##__VA_ARGS__); \
352 } while (0)
353
354 #else
355 #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__)
358 #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) \
392 do { \
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) \
401 do { \
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) \
412 do { \
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) \
421 do { \
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 */
439