xref: /openbmc/linux/fs/fscache/internal.h (revision b6dcefde)
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 
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 
86 extern int fscache_wait_bit(void *);
87 extern int fscache_wait_bit_interruptible(void *);
88 
89 /*
90  * object.c
91  */
92 extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
93 
94 extern void fscache_withdrawing_object(struct fscache_cache *,
95 				       struct fscache_object *);
96 extern void fscache_enqueue_object(struct fscache_object *);
97 
98 /*
99  * object-list.c
100  */
101 #ifdef CONFIG_FSCACHE_OBJECT_LIST
102 extern const struct file_operations fscache_objlist_fops;
103 
104 extern 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  */
112 extern int fscache_submit_exclusive_op(struct fscache_object *,
113 				       struct fscache_operation *);
114 extern int fscache_submit_op(struct fscache_object *,
115 			     struct fscache_operation *);
116 extern int fscache_cancel_op(struct fscache_operation *);
117 extern void fscache_abort_object(struct fscache_object *);
118 extern void fscache_start_operations(struct fscache_object *);
119 extern void fscache_operation_gc(struct work_struct *);
120 
121 /*
122  * proc.c
123  */
124 #ifdef CONFIG_PROC_FS
125 extern int __init fscache_proc_init(void);
126 extern 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
136 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
137 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
138 
139 extern atomic_t fscache_n_op_pend;
140 extern atomic_t fscache_n_op_run;
141 extern atomic_t fscache_n_op_enqueue;
142 extern atomic_t fscache_n_op_deferred_release;
143 extern atomic_t fscache_n_op_release;
144 extern atomic_t fscache_n_op_gc;
145 extern atomic_t fscache_n_op_cancelled;
146 extern atomic_t fscache_n_op_rejected;
147 
148 extern atomic_t fscache_n_attr_changed;
149 extern atomic_t fscache_n_attr_changed_ok;
150 extern atomic_t fscache_n_attr_changed_nobufs;
151 extern atomic_t fscache_n_attr_changed_nomem;
152 extern atomic_t fscache_n_attr_changed_calls;
153 
154 extern atomic_t fscache_n_allocs;
155 extern atomic_t fscache_n_allocs_ok;
156 extern atomic_t fscache_n_allocs_wait;
157 extern atomic_t fscache_n_allocs_nobufs;
158 extern atomic_t fscache_n_allocs_intr;
159 extern atomic_t fscache_n_allocs_object_dead;
160 extern atomic_t fscache_n_alloc_ops;
161 extern atomic_t fscache_n_alloc_op_waits;
162 
163 extern atomic_t fscache_n_retrievals;
164 extern atomic_t fscache_n_retrievals_ok;
165 extern atomic_t fscache_n_retrievals_wait;
166 extern atomic_t fscache_n_retrievals_nodata;
167 extern atomic_t fscache_n_retrievals_nobufs;
168 extern atomic_t fscache_n_retrievals_intr;
169 extern atomic_t fscache_n_retrievals_nomem;
170 extern atomic_t fscache_n_retrievals_object_dead;
171 extern atomic_t fscache_n_retrieval_ops;
172 extern atomic_t fscache_n_retrieval_op_waits;
173 
174 extern atomic_t fscache_n_stores;
175 extern atomic_t fscache_n_stores_ok;
176 extern atomic_t fscache_n_stores_again;
177 extern atomic_t fscache_n_stores_nobufs;
178 extern atomic_t fscache_n_stores_oom;
179 extern atomic_t fscache_n_store_ops;
180 extern atomic_t fscache_n_store_calls;
181 extern atomic_t fscache_n_store_pages;
182 extern atomic_t fscache_n_store_radix_deletes;
183 extern atomic_t fscache_n_store_pages_over_limit;
184 
185 extern atomic_t fscache_n_store_vmscan_not_storing;
186 extern atomic_t fscache_n_store_vmscan_gone;
187 extern atomic_t fscache_n_store_vmscan_busy;
188 extern atomic_t fscache_n_store_vmscan_cancelled;
189 
190 extern atomic_t fscache_n_marks;
191 extern atomic_t fscache_n_uncaches;
192 
193 extern atomic_t fscache_n_acquires;
194 extern atomic_t fscache_n_acquires_null;
195 extern atomic_t fscache_n_acquires_no_cache;
196 extern atomic_t fscache_n_acquires_ok;
197 extern atomic_t fscache_n_acquires_nobufs;
198 extern atomic_t fscache_n_acquires_oom;
199 
200 extern atomic_t fscache_n_updates;
201 extern atomic_t fscache_n_updates_null;
202 extern atomic_t fscache_n_updates_run;
203 
204 extern atomic_t fscache_n_relinquishes;
205 extern atomic_t fscache_n_relinquishes_null;
206 extern atomic_t fscache_n_relinquishes_waitcrt;
207 extern atomic_t fscache_n_relinquishes_retire;
208 
209 extern atomic_t fscache_n_cookie_index;
210 extern atomic_t fscache_n_cookie_data;
211 extern atomic_t fscache_n_cookie_special;
212 
213 extern atomic_t fscache_n_object_alloc;
214 extern atomic_t fscache_n_object_no_alloc;
215 extern atomic_t fscache_n_object_lookups;
216 extern atomic_t fscache_n_object_lookups_negative;
217 extern atomic_t fscache_n_object_lookups_positive;
218 extern atomic_t fscache_n_object_lookups_timed_out;
219 extern atomic_t fscache_n_object_created;
220 extern atomic_t fscache_n_object_avail;
221 extern atomic_t fscache_n_object_dead;
222 
223 extern atomic_t fscache_n_checkaux_none;
224 extern atomic_t fscache_n_checkaux_okay;
225 extern atomic_t fscache_n_checkaux_update;
226 extern atomic_t fscache_n_checkaux_obsolete;
227 
228 extern atomic_t fscache_n_cop_alloc_object;
229 extern atomic_t fscache_n_cop_lookup_object;
230 extern atomic_t fscache_n_cop_lookup_complete;
231 extern atomic_t fscache_n_cop_grab_object;
232 extern atomic_t fscache_n_cop_update_object;
233 extern atomic_t fscache_n_cop_drop_object;
234 extern atomic_t fscache_n_cop_put_object;
235 extern atomic_t fscache_n_cop_sync_cache;
236 extern atomic_t fscache_n_cop_attr_changed;
237 extern atomic_t fscache_n_cop_read_or_alloc_page;
238 extern atomic_t fscache_n_cop_read_or_alloc_pages;
239 extern atomic_t fscache_n_cop_allocate_page;
240 extern atomic_t fscache_n_cop_allocate_pages;
241 extern atomic_t fscache_n_cop_write_page;
242 extern atomic_t fscache_n_cop_uncache_page;
243 extern atomic_t fscache_n_cop_dissociate_pages;
244 
245 static inline void fscache_stat(atomic_t *stat)
246 {
247 	atomic_inc(stat);
248 }
249 
250 static inline void fscache_stat_d(atomic_t *stat)
251 {
252 	atomic_dec(stat);
253 }
254 
255 #define __fscache_stat(stat) (stat)
256 
257 extern 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  */
270 static 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  */
281 static 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  */
291 static inline
292 void *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  */
302 static inline
303 void 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 */
317 static inline __attribute__((format(printf, 1, 2)))
318 void _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, ...)			\
335 do {						\
336 	if (__do_kdebug(ENTER))			\
337 		kenter(FMT, ##__VA_ARGS__);	\
338 } while (0)
339 
340 #define _leave(FMT, ...)			\
341 do {						\
342 	if (__do_kdebug(LEAVE))			\
343 		kleave(FMT, ##__VA_ARGS__);	\
344 } while (0)
345 
346 #define _debug(FMT, ...)			\
347 do {						\
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)							\
390 do {									\
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)						\
399 do {									\
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)							\
410 do {									\
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)					\
419 do {									\
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 */
437