xref: /openbmc/linux/fs/fscache/internal.h (revision 6774def6)
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  */
40 extern struct list_head fscache_cache_list;
41 extern struct rw_semaphore fscache_addremove_sem;
42 
43 extern struct fscache_cache *fscache_select_cache_for_object(
44 	struct fscache_cookie *);
45 
46 /*
47  * cookie.c
48  */
49 extern struct kmem_cache *fscache_cookie_jar;
50 
51 extern void fscache_cookie_init_once(void *);
52 extern void __fscache_cookie_put(struct fscache_cookie *);
53 
54 /*
55  * fsdef.c
56  */
57 extern struct fscache_cookie fscache_fsdef_index;
58 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
59 
60 /*
61  * histogram.c
62  */
63 #ifdef CONFIG_FSCACHE_HISTOGRAM
64 extern atomic_t fscache_obj_instantiate_histogram[HZ];
65 extern atomic_t fscache_objs_histogram[HZ];
66 extern atomic_t fscache_ops_histogram[HZ];
67 extern atomic_t fscache_retrieval_delay_histogram[HZ];
68 extern atomic_t fscache_retrieval_histogram[HZ];
69 
70 static 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 
78 extern 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  */
87 extern unsigned fscache_defer_lookup;
88 extern unsigned fscache_defer_create;
89 extern unsigned fscache_debug;
90 extern struct kobject *fscache_root;
91 extern struct workqueue_struct *fscache_object_wq;
92 extern struct workqueue_struct *fscache_op_wq;
93 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
94 
95 static inline bool fscache_object_congested(void)
96 {
97 	return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
98 }
99 
100 extern int fscache_wait_atomic_t(atomic_t *);
101 
102 /*
103  * object.c
104  */
105 extern void fscache_enqueue_object(struct fscache_object *);
106 
107 /*
108  * object-list.c
109  */
110 #ifdef CONFIG_FSCACHE_OBJECT_LIST
111 extern const struct file_operations fscache_objlist_fops;
112 
113 extern void fscache_objlist_add(struct fscache_object *);
114 extern 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  */
123 extern int fscache_submit_exclusive_op(struct fscache_object *,
124 				       struct fscache_operation *);
125 extern int fscache_submit_op(struct fscache_object *,
126 			     struct fscache_operation *);
127 extern int fscache_cancel_op(struct fscache_operation *,
128 			     void (*)(struct fscache_operation *));
129 extern void fscache_cancel_all_ops(struct fscache_object *);
130 extern void fscache_abort_object(struct fscache_object *);
131 extern void fscache_start_operations(struct fscache_object *);
132 extern void fscache_operation_gc(struct work_struct *);
133 
134 /*
135  * page.c
136  */
137 extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
138 extern int fscache_wait_for_operation_activation(struct fscache_object *,
139 						 struct fscache_operation *,
140 						 atomic_t *,
141 						 atomic_t *,
142 						 void (*)(struct fscache_operation *));
143 extern void fscache_invalidate_writes(struct fscache_cookie *);
144 
145 /*
146  * proc.c
147  */
148 #ifdef CONFIG_PROC_FS
149 extern int __init fscache_proc_init(void);
150 extern void fscache_proc_cleanup(void);
151 #else
152 #define fscache_proc_init()	(0)
153 #define fscache_proc_cleanup()	do {} while (0)
154 #endif
155 
156 /*
157  * stats.c
158  */
159 #ifdef CONFIG_FSCACHE_STATS
160 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
161 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
162 
163 extern atomic_t fscache_n_op_pend;
164 extern atomic_t fscache_n_op_run;
165 extern atomic_t fscache_n_op_enqueue;
166 extern atomic_t fscache_n_op_deferred_release;
167 extern atomic_t fscache_n_op_release;
168 extern atomic_t fscache_n_op_gc;
169 extern atomic_t fscache_n_op_cancelled;
170 extern atomic_t fscache_n_op_rejected;
171 
172 extern atomic_t fscache_n_attr_changed;
173 extern atomic_t fscache_n_attr_changed_ok;
174 extern atomic_t fscache_n_attr_changed_nobufs;
175 extern atomic_t fscache_n_attr_changed_nomem;
176 extern atomic_t fscache_n_attr_changed_calls;
177 
178 extern atomic_t fscache_n_allocs;
179 extern atomic_t fscache_n_allocs_ok;
180 extern atomic_t fscache_n_allocs_wait;
181 extern atomic_t fscache_n_allocs_nobufs;
182 extern atomic_t fscache_n_allocs_intr;
183 extern atomic_t fscache_n_allocs_object_dead;
184 extern atomic_t fscache_n_alloc_ops;
185 extern atomic_t fscache_n_alloc_op_waits;
186 
187 extern atomic_t fscache_n_retrievals;
188 extern atomic_t fscache_n_retrievals_ok;
189 extern atomic_t fscache_n_retrievals_wait;
190 extern atomic_t fscache_n_retrievals_nodata;
191 extern atomic_t fscache_n_retrievals_nobufs;
192 extern atomic_t fscache_n_retrievals_intr;
193 extern atomic_t fscache_n_retrievals_nomem;
194 extern atomic_t fscache_n_retrievals_object_dead;
195 extern atomic_t fscache_n_retrieval_ops;
196 extern atomic_t fscache_n_retrieval_op_waits;
197 
198 extern atomic_t fscache_n_stores;
199 extern atomic_t fscache_n_stores_ok;
200 extern atomic_t fscache_n_stores_again;
201 extern atomic_t fscache_n_stores_nobufs;
202 extern atomic_t fscache_n_stores_oom;
203 extern atomic_t fscache_n_store_ops;
204 extern atomic_t fscache_n_store_calls;
205 extern atomic_t fscache_n_store_pages;
206 extern atomic_t fscache_n_store_radix_deletes;
207 extern atomic_t fscache_n_store_pages_over_limit;
208 
209 extern atomic_t fscache_n_store_vmscan_not_storing;
210 extern atomic_t fscache_n_store_vmscan_gone;
211 extern atomic_t fscache_n_store_vmscan_busy;
212 extern atomic_t fscache_n_store_vmscan_cancelled;
213 extern atomic_t fscache_n_store_vmscan_wait;
214 
215 extern atomic_t fscache_n_marks;
216 extern atomic_t fscache_n_uncaches;
217 
218 extern atomic_t fscache_n_acquires;
219 extern atomic_t fscache_n_acquires_null;
220 extern atomic_t fscache_n_acquires_no_cache;
221 extern atomic_t fscache_n_acquires_ok;
222 extern atomic_t fscache_n_acquires_nobufs;
223 extern atomic_t fscache_n_acquires_oom;
224 
225 extern atomic_t fscache_n_invalidates;
226 extern atomic_t fscache_n_invalidates_run;
227 
228 extern atomic_t fscache_n_updates;
229 extern atomic_t fscache_n_updates_null;
230 extern atomic_t fscache_n_updates_run;
231 
232 extern atomic_t fscache_n_relinquishes;
233 extern atomic_t fscache_n_relinquishes_null;
234 extern atomic_t fscache_n_relinquishes_waitcrt;
235 extern atomic_t fscache_n_relinquishes_retire;
236 
237 extern atomic_t fscache_n_cookie_index;
238 extern atomic_t fscache_n_cookie_data;
239 extern atomic_t fscache_n_cookie_special;
240 
241 extern atomic_t fscache_n_object_alloc;
242 extern atomic_t fscache_n_object_no_alloc;
243 extern atomic_t fscache_n_object_lookups;
244 extern atomic_t fscache_n_object_lookups_negative;
245 extern atomic_t fscache_n_object_lookups_positive;
246 extern atomic_t fscache_n_object_lookups_timed_out;
247 extern atomic_t fscache_n_object_created;
248 extern atomic_t fscache_n_object_avail;
249 extern atomic_t fscache_n_object_dead;
250 
251 extern atomic_t fscache_n_checkaux_none;
252 extern atomic_t fscache_n_checkaux_okay;
253 extern atomic_t fscache_n_checkaux_update;
254 extern atomic_t fscache_n_checkaux_obsolete;
255 
256 extern atomic_t fscache_n_cop_alloc_object;
257 extern atomic_t fscache_n_cop_lookup_object;
258 extern atomic_t fscache_n_cop_lookup_complete;
259 extern atomic_t fscache_n_cop_grab_object;
260 extern atomic_t fscache_n_cop_invalidate_object;
261 extern atomic_t fscache_n_cop_update_object;
262 extern atomic_t fscache_n_cop_drop_object;
263 extern atomic_t fscache_n_cop_put_object;
264 extern atomic_t fscache_n_cop_sync_cache;
265 extern atomic_t fscache_n_cop_attr_changed;
266 extern atomic_t fscache_n_cop_read_or_alloc_page;
267 extern atomic_t fscache_n_cop_read_or_alloc_pages;
268 extern atomic_t fscache_n_cop_allocate_page;
269 extern atomic_t fscache_n_cop_allocate_pages;
270 extern atomic_t fscache_n_cop_write_page;
271 extern atomic_t fscache_n_cop_uncache_page;
272 extern atomic_t fscache_n_cop_dissociate_pages;
273 
274 static inline void fscache_stat(atomic_t *stat)
275 {
276 	atomic_inc(stat);
277 }
278 
279 static inline void fscache_stat_d(atomic_t *stat)
280 {
281 	atomic_dec(stat);
282 }
283 
284 #define __fscache_stat(stat) (stat)
285 
286 extern const struct file_operations fscache_stats_fops;
287 #else
288 
289 #define __fscache_stat(stat) (NULL)
290 #define fscache_stat(stat) do {} while (0)
291 #define fscache_stat_d(stat) do {} while (0)
292 #endif
293 
294 /*
295  * raise an event on an object
296  * - if the event is not masked for that object, then the object is
297  *   queued for attention by the thread pool.
298  */
299 static inline void fscache_raise_event(struct fscache_object *object,
300 				       unsigned event)
301 {
302 	BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
303 #if 0
304 	printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
305 	       object->debug_id, object->event_mask, (1 << event));
306 #endif
307 	if (!test_and_set_bit(event, &object->events) &&
308 	    test_bit(event, &object->event_mask))
309 		fscache_enqueue_object(object);
310 }
311 
312 /*
313  * drop a reference to a cookie
314  */
315 static inline void fscache_cookie_put(struct fscache_cookie *cookie)
316 {
317 	BUG_ON(atomic_read(&cookie->usage) <= 0);
318 	if (atomic_dec_and_test(&cookie->usage))
319 		__fscache_cookie_put(cookie);
320 }
321 
322 /*
323  * get an extra reference to a netfs retrieval context
324  */
325 static inline
326 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
327 {
328 	if (cookie->def->get_context)
329 		cookie->def->get_context(cookie->netfs_data, context);
330 	return context;
331 }
332 
333 /*
334  * release a reference to a netfs retrieval context
335  */
336 static inline
337 void fscache_put_context(struct fscache_cookie *cookie, void *context)
338 {
339 	if (cookie->def->put_context)
340 		cookie->def->put_context(cookie->netfs_data, context);
341 }
342 
343 /*****************************************************************************/
344 /*
345  * debug tracing
346  */
347 #define dbgprintk(FMT, ...) \
348 	printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
349 
350 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
351 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
352 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
353 
354 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
355 
356 #ifdef __KDEBUG
357 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
358 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
359 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
360 
361 #elif defined(CONFIG_FSCACHE_DEBUG)
362 #define _enter(FMT, ...)			\
363 do {						\
364 	if (__do_kdebug(ENTER))			\
365 		kenter(FMT, ##__VA_ARGS__);	\
366 } while (0)
367 
368 #define _leave(FMT, ...)			\
369 do {						\
370 	if (__do_kdebug(LEAVE))			\
371 		kleave(FMT, ##__VA_ARGS__);	\
372 } while (0)
373 
374 #define _debug(FMT, ...)			\
375 do {						\
376 	if (__do_kdebug(DEBUG))			\
377 		kdebug(FMT, ##__VA_ARGS__);	\
378 } while (0)
379 
380 #else
381 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
382 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
383 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
384 #endif
385 
386 /*
387  * determine whether a particular optional debugging point should be logged
388  * - we need to go through three steps to persuade cpp to correctly join the
389  *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
390  */
391 #define ____do_kdebug(LEVEL, POINT) \
392 	unlikely((fscache_debug & \
393 		  (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
394 #define ___do_kdebug(LEVEL, POINT) \
395 	____do_kdebug(LEVEL, POINT)
396 #define __do_kdebug(POINT) \
397 	___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
398 
399 #define FSCACHE_DEBUG_CACHE	0
400 #define FSCACHE_DEBUG_COOKIE	1
401 #define FSCACHE_DEBUG_PAGE	2
402 #define FSCACHE_DEBUG_OPERATION	3
403 
404 #define FSCACHE_POINT_ENTER	1
405 #define FSCACHE_POINT_LEAVE	2
406 #define FSCACHE_POINT_DEBUG	4
407 
408 #ifndef FSCACHE_DEBUG_LEVEL
409 #define FSCACHE_DEBUG_LEVEL CACHE
410 #endif
411 
412 /*
413  * assertions
414  */
415 #if 1 /* defined(__KDEBUGALL) */
416 
417 #define ASSERT(X)							\
418 do {									\
419 	if (unlikely(!(X))) {						\
420 		pr_err("\n");					\
421 		pr_err("Assertion failed\n");	\
422 		BUG();							\
423 	}								\
424 } while (0)
425 
426 #define ASSERTCMP(X, OP, Y)						\
427 do {									\
428 	if (unlikely(!((X) OP (Y)))) {					\
429 		pr_err("\n");					\
430 		pr_err("Assertion failed\n");	\
431 		pr_err("%lx " #OP " %lx is false\n",		\
432 		       (unsigned long)(X), (unsigned long)(Y));		\
433 		BUG();							\
434 	}								\
435 } while (0)
436 
437 #define ASSERTIF(C, X)							\
438 do {									\
439 	if (unlikely((C) && !(X))) {					\
440 		pr_err("\n");					\
441 		pr_err("Assertion failed\n");	\
442 		BUG();							\
443 	}								\
444 } while (0)
445 
446 #define ASSERTIFCMP(C, X, OP, Y)					\
447 do {									\
448 	if (unlikely((C) && !((X) OP (Y)))) {				\
449 		pr_err("\n");					\
450 		pr_err("Assertion failed\n");	\
451 		pr_err("%lx " #OP " %lx is false\n",		\
452 		       (unsigned long)(X), (unsigned long)(Y));		\
453 		BUG();							\
454 	}								\
455 } while (0)
456 
457 #else
458 
459 #define ASSERT(X)			do {} while (0)
460 #define ASSERTCMP(X, OP, Y)		do {} while (0)
461 #define ASSERTIF(C, X)			do {} while (0)
462 #define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)
463 
464 #endif /* assert or not */
465