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;
85extern struct workqueue_struct *fscache_object_wq;
86extern struct workqueue_struct *fscache_op_wq;
87DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
88
89static inline bool fscache_object_congested(void)
90{
91 return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
92}
93
94extern int fscache_wait_bit(void *);
95extern int fscache_wait_bit_interruptible(void *);
96extern int fscache_wait_atomic_t(atomic_t *);
97
98/*
99 * object.c
100 */
101extern void fscache_enqueue_object(struct fscache_object *);
102
103/*
104 * object-list.c
105 */
106#ifdef CONFIG_FSCACHE_OBJECT_LIST
107extern const struct file_operations fscache_objlist_fops;
108
109extern void fscache_objlist_add(struct fscache_object *);
110extern void fscache_objlist_remove(struct fscache_object *);
111#else
112#define fscache_objlist_add(object) do {} while(0)
113#define fscache_objlist_remove(object) do {} while(0)
114#endif
115
116/*
117 * operation.c
118 */
119extern int fscache_submit_exclusive_op(struct fscache_object *,
120 struct fscache_operation *);
121extern int fscache_submit_op(struct fscache_object *,
122 struct fscache_operation *);
123extern int fscache_cancel_op(struct fscache_operation *,
124 void (*)(struct fscache_operation *));
125extern void fscache_cancel_all_ops(struct fscache_object *);
126extern void fscache_abort_object(struct fscache_object *);
127extern void fscache_start_operations(struct fscache_object *);
128extern void fscache_operation_gc(struct work_struct *);
129
130/*
131 * page.c
132 */
133extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
134extern int fscache_wait_for_operation_activation(struct fscache_object *,
135 struct fscache_operation *,
136 atomic_t *,
137 atomic_t *,
138 void (*)(struct fscache_operation *));
139extern void fscache_invalidate_writes(struct fscache_cookie *);
140
141/*
142 * proc.c
143 */
144#ifdef CONFIG_PROC_FS
145extern int __init fscache_proc_init(void);
146extern void fscache_proc_cleanup(void);
147#else
148#define fscache_proc_init() (0)
149#define fscache_proc_cleanup() do {} while (0)
150#endif
151
152/*
153 * stats.c
154 */
155#ifdef CONFIG_FSCACHE_STATS
156extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
157extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
158
159extern atomic_t fscache_n_op_pend;
160extern atomic_t fscache_n_op_run;
161extern atomic_t fscache_n_op_enqueue;
162extern atomic_t fscache_n_op_deferred_release;
163extern atomic_t fscache_n_op_release;
164extern atomic_t fscache_n_op_gc;
165extern atomic_t fscache_n_op_cancelled;
166extern atomic_t fscache_n_op_rejected;
167
168extern atomic_t fscache_n_attr_changed;
169extern atomic_t fscache_n_attr_changed_ok;
170extern atomic_t fscache_n_attr_changed_nobufs;
171extern atomic_t fscache_n_attr_changed_nomem;
172extern atomic_t fscache_n_attr_changed_calls;
173
174extern atomic_t fscache_n_allocs;
175extern atomic_t fscache_n_allocs_ok;
176extern atomic_t fscache_n_allocs_wait;
177extern atomic_t fscache_n_allocs_nobufs;
178extern atomic_t fscache_n_allocs_intr;
179extern atomic_t fscache_n_allocs_object_dead;
180extern atomic_t fscache_n_alloc_ops;
181extern atomic_t fscache_n_alloc_op_waits;
182
183extern atomic_t fscache_n_retrievals;
184extern atomic_t fscache_n_retrievals_ok;
185extern atomic_t fscache_n_retrievals_wait;
186extern atomic_t fscache_n_retrievals_nodata;
187extern atomic_t fscache_n_retrievals_nobufs;
188extern atomic_t fscache_n_retrievals_intr;
189extern atomic_t fscache_n_retrievals_nomem;
190extern atomic_t fscache_n_retrievals_object_dead;
191extern atomic_t fscache_n_retrieval_ops;
192extern atomic_t fscache_n_retrieval_op_waits;
193
194extern atomic_t fscache_n_stores;
195extern atomic_t fscache_n_stores_ok;
196extern atomic_t fscache_n_stores_again;
197extern atomic_t fscache_n_stores_nobufs;
198extern atomic_t fscache_n_stores_oom;
199extern atomic_t fscache_n_store_ops;
200extern atomic_t fscache_n_store_calls;
201extern atomic_t fscache_n_store_pages;
202extern atomic_t fscache_n_store_radix_deletes;
203extern atomic_t fscache_n_store_pages_over_limit;
204
205extern atomic_t fscache_n_store_vmscan_not_storing;
206extern atomic_t fscache_n_store_vmscan_gone;
207extern atomic_t fscache_n_store_vmscan_busy;
208extern atomic_t fscache_n_store_vmscan_cancelled;
209extern atomic_t fscache_n_store_vmscan_wait;
210
211extern atomic_t fscache_n_marks;
212extern atomic_t fscache_n_uncaches;
213
214extern atomic_t fscache_n_acquires;
215extern atomic_t fscache_n_acquires_null;
216extern atomic_t fscache_n_acquires_no_cache;
217extern atomic_t fscache_n_acquires_ok;
218extern atomic_t fscache_n_acquires_nobufs;
219extern atomic_t fscache_n_acquires_oom;
220
221extern atomic_t fscache_n_invalidates;
222extern atomic_t fscache_n_invalidates_run;
223
224extern atomic_t fscache_n_updates;
225extern atomic_t fscache_n_updates_null;
226extern atomic_t fscache_n_updates_run;
227
228extern atomic_t fscache_n_relinquishes;
229extern atomic_t fscache_n_relinquishes_null;
230extern atomic_t fscache_n_relinquishes_waitcrt;
231extern atomic_t fscache_n_relinquishes_retire;
232
233extern atomic_t fscache_n_cookie_index;
234extern atomic_t fscache_n_cookie_data;
235extern atomic_t fscache_n_cookie_special;
236
237extern atomic_t fscache_n_object_alloc;
238extern atomic_t fscache_n_object_no_alloc;
239extern atomic_t fscache_n_object_lookups;
240extern atomic_t fscache_n_object_lookups_negative;
241extern atomic_t fscache_n_object_lookups_positive;
242extern atomic_t fscache_n_object_lookups_timed_out;
243extern atomic_t fscache_n_object_created;
244extern atomic_t fscache_n_object_avail;
245extern atomic_t fscache_n_object_dead;
246
247extern atomic_t fscache_n_checkaux_none;
248extern atomic_t fscache_n_checkaux_okay;
249extern atomic_t fscache_n_checkaux_update;
250extern atomic_t fscache_n_checkaux_obsolete;
251
252extern atomic_t fscache_n_cop_alloc_object;
253extern atomic_t fscache_n_cop_lookup_object;
254extern atomic_t fscache_n_cop_lookup_complete;
255extern atomic_t fscache_n_cop_grab_object;
256extern atomic_t fscache_n_cop_invalidate_object;
257extern atomic_t fscache_n_cop_update_object;
258extern atomic_t fscache_n_cop_drop_object;
259extern atomic_t fscache_n_cop_put_object;
260extern atomic_t fscache_n_cop_sync_cache;
261extern atomic_t fscache_n_cop_attr_changed;
262extern atomic_t fscache_n_cop_read_or_alloc_page;
263extern atomic_t fscache_n_cop_read_or_alloc_pages;
264extern atomic_t fscache_n_cop_allocate_page;
265extern atomic_t fscache_n_cop_allocate_pages;
266extern atomic_t fscache_n_cop_write_page;
267extern atomic_t fscache_n_cop_uncache_page;
268extern atomic_t fscache_n_cop_dissociate_pages;
269
270static inline void fscache_stat(atomic_t *stat)
271{
272 atomic_inc(stat);
273}
274
275static inline void fscache_stat_d(atomic_t *stat)
276{
277 atomic_dec(stat);
278}
279
280#define __fscache_stat(stat) (stat)
281
282extern const struct file_operations fscache_stats_fops;
283#else
284
285#define __fscache_stat(stat) (NULL)
286#define fscache_stat(stat) do {} while (0)
287#define fscache_stat_d(stat) do {} while (0)
288#endif
289
290/*
291 * raise an event on an object
292 * - if the event is not masked for that object, then the object is
293 * queued for attention by the thread pool.
294 */
295static inline void fscache_raise_event(struct fscache_object *object,
296 unsigned event)
297{
298 BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
299#if 0
300 printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
301 object->debug_id, object->event_mask, (1 << event));
302#endif
303 if (!test_and_set_bit(event, &object->events) &&
304 test_bit(event, &object->event_mask))
305 fscache_enqueue_object(object);
306}
307
308/*
309 * drop a reference to a cookie
310 */
311static inline void fscache_cookie_put(struct fscache_cookie *cookie)
312{
313 BUG_ON(atomic_read(&cookie->usage) <= 0);
314 if (atomic_dec_and_test(&cookie->usage))
315 __fscache_cookie_put(cookie);
316}
317
318/*
319 * get an extra reference to a netfs retrieval context
320 */
321static inline
322void *fscache_get_context(struct fscache_cookie *cookie, void *context)
323{
324 if (cookie->def->get_context)
325 cookie->def->get_context(cookie->netfs_data, context);
326 return context;
327}
328
329/*
330 * release a reference to a netfs retrieval context
331 */
332static inline
333void fscache_put_context(struct fscache_cookie *cookie, void *context)
334{
335 if (cookie->def->put_context)
336 cookie->def->put_context(cookie->netfs_data, context);
337}
338
339/*****************************************************************************/
340/*
341 * debug tracing
342 */
343#define dbgprintk(FMT, ...) \
344 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
345
346#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
347#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
348#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
349
350#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
351
352#ifdef __KDEBUG
353#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
354#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
355#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
356
357#elif defined(CONFIG_FSCACHE_DEBUG)
358#define _enter(FMT, ...) \
359do { \
360 if (__do_kdebug(ENTER)) \
361 kenter(FMT, ##__VA_ARGS__); \
362} while (0)
363
364#define _leave(FMT, ...) \
365do { \
366 if (__do_kdebug(LEAVE)) \
367 kleave(FMT, ##__VA_ARGS__); \
368} while (0)
369
370#define _debug(FMT, ...) \
371do { \
372 if (__do_kdebug(DEBUG)) \
373 kdebug(FMT, ##__VA_ARGS__); \
374} while (0)
375
376#else
377#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
378#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
379#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
380#endif
381
382/*
383 * determine whether a particular optional debugging point should be logged
384 * - we need to go through three steps to persuade cpp to correctly join the
385 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
386 */
387#define ____do_kdebug(LEVEL, POINT) \
388 unlikely((fscache_debug & \
389 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
390#define ___do_kdebug(LEVEL, POINT) \
391 ____do_kdebug(LEVEL, POINT)
392#define __do_kdebug(POINT) \
393 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
394
395#define FSCACHE_DEBUG_CACHE 0
396#define FSCACHE_DEBUG_COOKIE 1
397#define FSCACHE_DEBUG_PAGE 2
398#define FSCACHE_DEBUG_OPERATION 3
399
400#define FSCACHE_POINT_ENTER 1
401#define FSCACHE_POINT_LEAVE 2
402#define FSCACHE_POINT_DEBUG 4
403
404#ifndef FSCACHE_DEBUG_LEVEL
405#define FSCACHE_DEBUG_LEVEL CACHE
406#endif
407
408/*
409 * assertions
410 */
411#if 1 /* defined(__KDEBUGALL) */
412
413#define ASSERT(X) \
414do { \
415 if (unlikely(!(X))) { \
416 printk(KERN_ERR "\n"); \
417 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
418 BUG(); \
419 } \
420} while (0)
421
422#define ASSERTCMP(X, OP, Y) \
423do { \
424 if (unlikely(!((X) OP (Y)))) { \
425 printk(KERN_ERR "\n"); \
426 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
427 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
428 (unsigned long)(X), (unsigned long)(Y)); \
429 BUG(); \
430 } \
431} while (0)
432
433#define ASSERTIF(C, X) \
434do { \
435 if (unlikely((C) && !(X))) { \
436 printk(KERN_ERR "\n"); \
437 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
438 BUG(); \
439 } \
440} while (0)
441
442#define ASSERTIFCMP(C, X, OP, Y) \
443do { \
444 if (unlikely((C) && !((X) OP (Y)))) { \
445 printk(KERN_ERR "\n"); \
446 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
447 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
448 (unsigned long)(X), (unsigned long)(Y)); \
449 BUG(); \
450 } \
451} while (0)
452
453#else
454
455#define ASSERT(X) do {} while (0)
456#define ASSERTCMP(X, OP, Y) do {} while (0)
457#define ASSERTIF(C, X) do {} while (0)
458#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
459
460#endif /* assert or not */