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 <trace/events/fscache.h>
33 #include <linux/sched.h>
34 #include <linux/seq_file.h>
35
36 #define FSCACHE_MIN_THREADS 4
37 #define FSCACHE_MAX_THREADS 32
38
39 /*
40 * cache.c
41 */
42 extern struct list_head fscache_cache_list;
43 extern struct rw_semaphore fscache_addremove_sem;
44
45 extern struct fscache_cache *fscache_select_cache_for_object(
46 struct fscache_cookie *);
47
48 /*
49 * cookie.c
50 */
51 extern struct kmem_cache *fscache_cookie_jar;
52
53 extern void fscache_free_cookie(struct fscache_cookie *);
54 extern struct fscache_cookie *fscache_alloc_cookie(struct fscache_cookie *,
55 const struct fscache_cookie_def *,
56 const void *, size_t,
57 const void *, size_t,
58 void *, loff_t);
59 extern struct fscache_cookie *fscache_hash_cookie(struct fscache_cookie *);
60 extern void fscache_cookie_put(struct fscache_cookie *,
61 enum fscache_cookie_trace);
62
63 /*
64 * fsdef.c
65 */
66 extern struct fscache_cookie fscache_fsdef_index;
67 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
68
69 /*
70 * histogram.c
71 */
72 #ifdef CONFIG_FSCACHE_HISTOGRAM
73 extern atomic_t fscache_obj_instantiate_histogram[HZ];
74 extern atomic_t fscache_objs_histogram[HZ];
75 extern atomic_t fscache_ops_histogram[HZ];
76 extern atomic_t fscache_retrieval_delay_histogram[HZ];
77 extern atomic_t fscache_retrieval_histogram[HZ];
78
fscache_hist(atomic_t histogram[],unsigned long start_jif)79 static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
80 {
81 unsigned long jif = jiffies - start_jif;
82 if (jif >= HZ)
83 jif = HZ - 1;
84 atomic_inc(&histogram[jif]);
85 }
86
87 extern const struct seq_operations fscache_histogram_ops;
88
89 #else
90 #define fscache_hist(hist, start_jif) do {} while (0)
91 #endif
92
93 /*
94 * main.c
95 */
96 extern unsigned fscache_defer_lookup;
97 extern unsigned fscache_defer_create;
98 extern unsigned fscache_debug;
99 extern struct kobject *fscache_root;
100 extern struct workqueue_struct *fscache_object_wq;
101 extern struct workqueue_struct *fscache_op_wq;
102 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
103
104 extern unsigned int fscache_hash(unsigned int salt, unsigned int *data, unsigned int n);
105
fscache_object_congested(void)106 static inline bool fscache_object_congested(void)
107 {
108 return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
109 }
110
111 /*
112 * object.c
113 */
114 extern void fscache_enqueue_object(struct fscache_object *);
115
116 /*
117 * object-list.c
118 */
119 #ifdef CONFIG_FSCACHE_OBJECT_LIST
120 extern const struct file_operations fscache_objlist_fops;
121
122 extern void fscache_objlist_add(struct fscache_object *);
123 extern void fscache_objlist_remove(struct fscache_object *);
124 #else
125 #define fscache_objlist_add(object) do {} while(0)
126 #define fscache_objlist_remove(object) do {} while(0)
127 #endif
128
129 /*
130 * operation.c
131 */
132 extern int fscache_submit_exclusive_op(struct fscache_object *,
133 struct fscache_operation *);
134 extern int fscache_submit_op(struct fscache_object *,
135 struct fscache_operation *);
136 extern int fscache_cancel_op(struct fscache_operation *, bool);
137 extern void fscache_cancel_all_ops(struct fscache_object *);
138 extern void fscache_abort_object(struct fscache_object *);
139 extern void fscache_start_operations(struct fscache_object *);
140 extern void fscache_operation_gc(struct work_struct *);
141
142 /*
143 * page.c
144 */
145 extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
146 extern int fscache_wait_for_operation_activation(struct fscache_object *,
147 struct fscache_operation *,
148 atomic_t *,
149 atomic_t *);
150 extern void fscache_invalidate_writes(struct fscache_cookie *);
151
152 /*
153 * proc.c
154 */
155 #ifdef CONFIG_PROC_FS
156 extern int __init fscache_proc_init(void);
157 extern void fscache_proc_cleanup(void);
158 #else
159 #define fscache_proc_init() (0)
160 #define fscache_proc_cleanup() do {} while (0)
161 #endif
162
163 /*
164 * stats.c
165 */
166 #ifdef CONFIG_FSCACHE_STATS
167 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
168 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
169
170 extern atomic_t fscache_n_op_pend;
171 extern atomic_t fscache_n_op_run;
172 extern atomic_t fscache_n_op_enqueue;
173 extern atomic_t fscache_n_op_deferred_release;
174 extern atomic_t fscache_n_op_initialised;
175 extern atomic_t fscache_n_op_release;
176 extern atomic_t fscache_n_op_gc;
177 extern atomic_t fscache_n_op_cancelled;
178 extern atomic_t fscache_n_op_rejected;
179
180 extern atomic_t fscache_n_attr_changed;
181 extern atomic_t fscache_n_attr_changed_ok;
182 extern atomic_t fscache_n_attr_changed_nobufs;
183 extern atomic_t fscache_n_attr_changed_nomem;
184 extern atomic_t fscache_n_attr_changed_calls;
185
186 extern atomic_t fscache_n_allocs;
187 extern atomic_t fscache_n_allocs_ok;
188 extern atomic_t fscache_n_allocs_wait;
189 extern atomic_t fscache_n_allocs_nobufs;
190 extern atomic_t fscache_n_allocs_intr;
191 extern atomic_t fscache_n_allocs_object_dead;
192 extern atomic_t fscache_n_alloc_ops;
193 extern atomic_t fscache_n_alloc_op_waits;
194
195 extern atomic_t fscache_n_retrievals;
196 extern atomic_t fscache_n_retrievals_ok;
197 extern atomic_t fscache_n_retrievals_wait;
198 extern atomic_t fscache_n_retrievals_nodata;
199 extern atomic_t fscache_n_retrievals_nobufs;
200 extern atomic_t fscache_n_retrievals_intr;
201 extern atomic_t fscache_n_retrievals_nomem;
202 extern atomic_t fscache_n_retrievals_object_dead;
203 extern atomic_t fscache_n_retrieval_ops;
204 extern atomic_t fscache_n_retrieval_op_waits;
205
206 extern atomic_t fscache_n_stores;
207 extern atomic_t fscache_n_stores_ok;
208 extern atomic_t fscache_n_stores_again;
209 extern atomic_t fscache_n_stores_nobufs;
210 extern atomic_t fscache_n_stores_oom;
211 extern atomic_t fscache_n_store_ops;
212 extern atomic_t fscache_n_store_calls;
213 extern atomic_t fscache_n_store_pages;
214 extern atomic_t fscache_n_store_radix_deletes;
215 extern atomic_t fscache_n_store_pages_over_limit;
216
217 extern atomic_t fscache_n_store_vmscan_not_storing;
218 extern atomic_t fscache_n_store_vmscan_gone;
219 extern atomic_t fscache_n_store_vmscan_busy;
220 extern atomic_t fscache_n_store_vmscan_cancelled;
221 extern atomic_t fscache_n_store_vmscan_wait;
222
223 extern atomic_t fscache_n_marks;
224 extern atomic_t fscache_n_uncaches;
225
226 extern atomic_t fscache_n_acquires;
227 extern atomic_t fscache_n_acquires_null;
228 extern atomic_t fscache_n_acquires_no_cache;
229 extern atomic_t fscache_n_acquires_ok;
230 extern atomic_t fscache_n_acquires_nobufs;
231 extern atomic_t fscache_n_acquires_oom;
232
233 extern atomic_t fscache_n_invalidates;
234 extern atomic_t fscache_n_invalidates_run;
235
236 extern atomic_t fscache_n_updates;
237 extern atomic_t fscache_n_updates_null;
238 extern atomic_t fscache_n_updates_run;
239
240 extern atomic_t fscache_n_relinquishes;
241 extern atomic_t fscache_n_relinquishes_null;
242 extern atomic_t fscache_n_relinquishes_waitcrt;
243 extern atomic_t fscache_n_relinquishes_retire;
244
245 extern atomic_t fscache_n_cookie_index;
246 extern atomic_t fscache_n_cookie_data;
247 extern atomic_t fscache_n_cookie_special;
248
249 extern atomic_t fscache_n_object_alloc;
250 extern atomic_t fscache_n_object_no_alloc;
251 extern atomic_t fscache_n_object_lookups;
252 extern atomic_t fscache_n_object_lookups_negative;
253 extern atomic_t fscache_n_object_lookups_positive;
254 extern atomic_t fscache_n_object_lookups_timed_out;
255 extern atomic_t fscache_n_object_created;
256 extern atomic_t fscache_n_object_avail;
257 extern atomic_t fscache_n_object_dead;
258
259 extern atomic_t fscache_n_checkaux_none;
260 extern atomic_t fscache_n_checkaux_okay;
261 extern atomic_t fscache_n_checkaux_update;
262 extern atomic_t fscache_n_checkaux_obsolete;
263
264 extern atomic_t fscache_n_cop_alloc_object;
265 extern atomic_t fscache_n_cop_lookup_object;
266 extern atomic_t fscache_n_cop_lookup_complete;
267 extern atomic_t fscache_n_cop_grab_object;
268 extern atomic_t fscache_n_cop_invalidate_object;
269 extern atomic_t fscache_n_cop_update_object;
270 extern atomic_t fscache_n_cop_drop_object;
271 extern atomic_t fscache_n_cop_put_object;
272 extern atomic_t fscache_n_cop_sync_cache;
273 extern atomic_t fscache_n_cop_attr_changed;
274 extern atomic_t fscache_n_cop_read_or_alloc_page;
275 extern atomic_t fscache_n_cop_read_or_alloc_pages;
276 extern atomic_t fscache_n_cop_allocate_page;
277 extern atomic_t fscache_n_cop_allocate_pages;
278 extern atomic_t fscache_n_cop_write_page;
279 extern atomic_t fscache_n_cop_uncache_page;
280 extern atomic_t fscache_n_cop_dissociate_pages;
281
282 extern atomic_t fscache_n_cache_no_space_reject;
283 extern atomic_t fscache_n_cache_stale_objects;
284 extern atomic_t fscache_n_cache_retired_objects;
285 extern atomic_t fscache_n_cache_culled_objects;
286
fscache_stat(atomic_t * stat)287 static inline void fscache_stat(atomic_t *stat)
288 {
289 atomic_inc(stat);
290 }
291
fscache_stat_d(atomic_t * stat)292 static inline void fscache_stat_d(atomic_t *stat)
293 {
294 atomic_dec(stat);
295 }
296
297 #define __fscache_stat(stat) (stat)
298
299 int fscache_stats_show(struct seq_file *m, void *v);
300 #else
301
302 #define __fscache_stat(stat) (NULL)
303 #define fscache_stat(stat) do {} while (0)
304 #define fscache_stat_d(stat) do {} while (0)
305 #endif
306
307 /*
308 * raise an event on an object
309 * - if the event is not masked for that object, then the object is
310 * queued for attention by the thread pool.
311 */
fscache_raise_event(struct fscache_object * object,unsigned event)312 static inline void fscache_raise_event(struct fscache_object *object,
313 unsigned event)
314 {
315 BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
316 #if 0
317 printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
318 object->debug_id, object->event_mask, (1 << event));
319 #endif
320 if (!test_and_set_bit(event, &object->events) &&
321 test_bit(event, &object->event_mask))
322 fscache_enqueue_object(object);
323 }
324
fscache_cookie_get(struct fscache_cookie * cookie,enum fscache_cookie_trace where)325 static inline void fscache_cookie_get(struct fscache_cookie *cookie,
326 enum fscache_cookie_trace where)
327 {
328 int usage = atomic_inc_return(&cookie->usage);
329
330 trace_fscache_cookie(cookie, where, usage);
331 }
332
333 /*
334 * get an extra reference to a netfs retrieval context
335 */
336 static inline
fscache_get_context(struct fscache_cookie * cookie,void * context)337 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
338 {
339 if (cookie->def->get_context)
340 cookie->def->get_context(cookie->netfs_data, context);
341 return context;
342 }
343
344 /*
345 * release a reference to a netfs retrieval context
346 */
347 static inline
fscache_put_context(struct fscache_cookie * cookie,void * context)348 void fscache_put_context(struct fscache_cookie *cookie, void *context)
349 {
350 if (cookie->def->put_context)
351 cookie->def->put_context(cookie->netfs_data, context);
352 }
353
354 /*
355 * Update the auxiliary data on a cookie.
356 */
357 static inline
fscache_update_aux(struct fscache_cookie * cookie,const void * aux_data)358 void fscache_update_aux(struct fscache_cookie *cookie, const void *aux_data)
359 {
360 void *p;
361
362 if (!aux_data)
363 return;
364 if (cookie->aux_len <= sizeof(cookie->inline_aux))
365 p = cookie->inline_aux;
366 else
367 p = cookie->aux;
368
369 if (memcmp(p, aux_data, cookie->aux_len) != 0) {
370 memcpy(p, aux_data, cookie->aux_len);
371 set_bit(FSCACHE_COOKIE_AUX_UPDATED, &cookie->flags);
372 }
373 }
374
375 /*****************************************************************************/
376 /*
377 * debug tracing
378 */
379 #define dbgprintk(FMT, ...) \
380 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
381
382 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
383 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
384 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
385
386 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
387
388 #ifdef __KDEBUG
389 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
390 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
391 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
392
393 #elif defined(CONFIG_FSCACHE_DEBUG)
394 #define _enter(FMT, ...) \
395 do { \
396 if (__do_kdebug(ENTER)) \
397 kenter(FMT, ##__VA_ARGS__); \
398 } while (0)
399
400 #define _leave(FMT, ...) \
401 do { \
402 if (__do_kdebug(LEAVE)) \
403 kleave(FMT, ##__VA_ARGS__); \
404 } while (0)
405
406 #define _debug(FMT, ...) \
407 do { \
408 if (__do_kdebug(DEBUG)) \
409 kdebug(FMT, ##__VA_ARGS__); \
410 } while (0)
411
412 #else
413 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
414 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
415 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
416 #endif
417
418 /*
419 * determine whether a particular optional debugging point should be logged
420 * - we need to go through three steps to persuade cpp to correctly join the
421 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
422 */
423 #define ____do_kdebug(LEVEL, POINT) \
424 unlikely((fscache_debug & \
425 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
426 #define ___do_kdebug(LEVEL, POINT) \
427 ____do_kdebug(LEVEL, POINT)
428 #define __do_kdebug(POINT) \
429 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
430
431 #define FSCACHE_DEBUG_CACHE 0
432 #define FSCACHE_DEBUG_COOKIE 1
433 #define FSCACHE_DEBUG_PAGE 2
434 #define FSCACHE_DEBUG_OPERATION 3
435
436 #define FSCACHE_POINT_ENTER 1
437 #define FSCACHE_POINT_LEAVE 2
438 #define FSCACHE_POINT_DEBUG 4
439
440 #ifndef FSCACHE_DEBUG_LEVEL
441 #define FSCACHE_DEBUG_LEVEL CACHE
442 #endif
443
444 /*
445 * assertions
446 */
447 #if 1 /* defined(__KDEBUGALL) */
448
449 #define ASSERT(X) \
450 do { \
451 if (unlikely(!(X))) { \
452 pr_err("\n"); \
453 pr_err("Assertion failed\n"); \
454 BUG(); \
455 } \
456 } while (0)
457
458 #define ASSERTCMP(X, OP, Y) \
459 do { \
460 if (unlikely(!((X) OP (Y)))) { \
461 pr_err("\n"); \
462 pr_err("Assertion failed\n"); \
463 pr_err("%lx " #OP " %lx is false\n", \
464 (unsigned long)(X), (unsigned long)(Y)); \
465 BUG(); \
466 } \
467 } while (0)
468
469 #define ASSERTIF(C, X) \
470 do { \
471 if (unlikely((C) && !(X))) { \
472 pr_err("\n"); \
473 pr_err("Assertion failed\n"); \
474 BUG(); \
475 } \
476 } while (0)
477
478 #define ASSERTIFCMP(C, X, OP, Y) \
479 do { \
480 if (unlikely((C) && !((X) OP (Y)))) { \
481 pr_err("\n"); \
482 pr_err("Assertion failed\n"); \
483 pr_err("%lx " #OP " %lx is false\n", \
484 (unsigned long)(X), (unsigned long)(Y)); \
485 BUG(); \
486 } \
487 } while (0)
488
489 #else
490
491 #define ASSERT(X) do {} while (0)
492 #define ASSERTCMP(X, OP, Y) do {} while (0)
493 #define ASSERTIF(C, X) do {} while (0)
494 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
495
496 #endif /* assert or not */
497