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 *);
96
97/*
98 * object.c
99 */
100extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];
101
102extern void fscache_withdrawing_object(struct fscache_cache *,
103 struct fscache_object *);
104extern void fscache_enqueue_object(struct fscache_object *);
105
106/*
107 * object-list.c
108 */
109#ifdef CONFIG_FSCACHE_OBJECT_LIST
110extern const struct file_operations fscache_objlist_fops;
111
112extern 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 */
120extern int fscache_submit_exclusive_op(struct fscache_object *,
121 struct fscache_operation *);
122extern int fscache_submit_op(struct fscache_object *,
123 struct fscache_operation *);
124extern int fscache_cancel_op(struct fscache_operation *,
125 void (*)(struct fscache_operation *));
126extern void fscache_cancel_all_ops(struct fscache_object *);
127extern void fscache_abort_object(struct fscache_object *);
128extern void fscache_start_operations(struct fscache_object *);
129extern void fscache_operation_gc(struct work_struct *);
130
131/*
132 * page.c
133 */
134extern void fscache_invalidate_writes(struct fscache_cookie *);
135
136/*
137 * proc.c
138 */
139#ifdef CONFIG_PROC_FS
140extern int __init fscache_proc_init(void);
141extern void fscache_proc_cleanup(void);
142#else
143#define fscache_proc_init() (0)
144#define fscache_proc_cleanup() do {} while (0)
145#endif
146
147/*
148 * stats.c
149 */
150#ifdef CONFIG_FSCACHE_STATS
151extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
152extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
153
154extern atomic_t fscache_n_op_pend;
155extern atomic_t fscache_n_op_run;
156extern atomic_t fscache_n_op_enqueue;
157extern atomic_t fscache_n_op_deferred_release;
158extern atomic_t fscache_n_op_release;
159extern atomic_t fscache_n_op_gc;
160extern atomic_t fscache_n_op_cancelled;
161extern atomic_t fscache_n_op_rejected;
162
163extern atomic_t fscache_n_attr_changed;
164extern atomic_t fscache_n_attr_changed_ok;
165extern atomic_t fscache_n_attr_changed_nobufs;
166extern atomic_t fscache_n_attr_changed_nomem;
167extern atomic_t fscache_n_attr_changed_calls;
168
169extern atomic_t fscache_n_allocs;
170extern atomic_t fscache_n_allocs_ok;
171extern atomic_t fscache_n_allocs_wait;
172extern atomic_t fscache_n_allocs_nobufs;
173extern atomic_t fscache_n_allocs_intr;
174extern atomic_t fscache_n_allocs_object_dead;
175extern atomic_t fscache_n_alloc_ops;
176extern atomic_t fscache_n_alloc_op_waits;
177
178extern atomic_t fscache_n_retrievals;
179extern atomic_t fscache_n_retrievals_ok;
180extern atomic_t fscache_n_retrievals_wait;
181extern atomic_t fscache_n_retrievals_nodata;
182extern atomic_t fscache_n_retrievals_nobufs;
183extern atomic_t fscache_n_retrievals_intr;
184extern atomic_t fscache_n_retrievals_nomem;
185extern atomic_t fscache_n_retrievals_object_dead;
186extern atomic_t fscache_n_retrieval_ops;
187extern atomic_t fscache_n_retrieval_op_waits;
188
189extern atomic_t fscache_n_stores;
190extern atomic_t fscache_n_stores_ok;
191extern atomic_t fscache_n_stores_again;
192extern atomic_t fscache_n_stores_nobufs;
193extern atomic_t fscache_n_stores_oom;
194extern atomic_t fscache_n_store_ops;
195extern atomic_t fscache_n_store_calls;
196extern atomic_t fscache_n_store_pages;
197extern atomic_t fscache_n_store_radix_deletes;
198extern atomic_t fscache_n_store_pages_over_limit;
199
200extern atomic_t fscache_n_store_vmscan_not_storing;
201extern atomic_t fscache_n_store_vmscan_gone;
202extern atomic_t fscache_n_store_vmscan_busy;
203extern atomic_t fscache_n_store_vmscan_cancelled;
204extern atomic_t fscache_n_store_vmscan_wait;
205
206extern atomic_t fscache_n_marks;
207extern atomic_t fscache_n_uncaches;
208
209extern atomic_t fscache_n_acquires;
210extern atomic_t fscache_n_acquires_null;
211extern atomic_t fscache_n_acquires_no_cache;
212extern atomic_t fscache_n_acquires_ok;
213extern atomic_t fscache_n_acquires_nobufs;
214extern atomic_t fscache_n_acquires_oom;
215
216extern atomic_t fscache_n_invalidates;
217extern atomic_t fscache_n_invalidates_run;
218
219extern atomic_t fscache_n_updates;
220extern atomic_t fscache_n_updates_null;
221extern atomic_t fscache_n_updates_run;
222
223extern atomic_t fscache_n_relinquishes;
224extern atomic_t fscache_n_relinquishes_null;
225extern atomic_t fscache_n_relinquishes_waitcrt;
226extern atomic_t fscache_n_relinquishes_retire;
227
228extern atomic_t fscache_n_cookie_index;
229extern atomic_t fscache_n_cookie_data;
230extern atomic_t fscache_n_cookie_special;
231
232extern atomic_t fscache_n_object_alloc;
233extern atomic_t fscache_n_object_no_alloc;
234extern atomic_t fscache_n_object_lookups;
235extern atomic_t fscache_n_object_lookups_negative;
236extern atomic_t fscache_n_object_lookups_positive;
237extern atomic_t fscache_n_object_lookups_timed_out;
238extern atomic_t fscache_n_object_created;
239extern atomic_t fscache_n_object_avail;
240extern atomic_t fscache_n_object_dead;
241
242extern atomic_t fscache_n_checkaux_none;
243extern atomic_t fscache_n_checkaux_okay;
244extern atomic_t fscache_n_checkaux_update;
245extern atomic_t fscache_n_checkaux_obsolete;
246
247extern atomic_t fscache_n_cop_alloc_object;
248extern atomic_t fscache_n_cop_lookup_object;
249extern atomic_t fscache_n_cop_lookup_complete;
250extern atomic_t fscache_n_cop_grab_object;
251extern atomic_t fscache_n_cop_invalidate_object;
252extern atomic_t fscache_n_cop_update_object;
253extern atomic_t fscache_n_cop_drop_object;
254extern atomic_t fscache_n_cop_put_object;
255extern atomic_t fscache_n_cop_sync_cache;
256extern atomic_t fscache_n_cop_attr_changed;
257extern atomic_t fscache_n_cop_read_or_alloc_page;
258extern atomic_t fscache_n_cop_read_or_alloc_pages;
259extern atomic_t fscache_n_cop_allocate_page;
260extern atomic_t fscache_n_cop_allocate_pages;
261extern atomic_t fscache_n_cop_write_page;
262extern atomic_t fscache_n_cop_uncache_page;
263extern atomic_t fscache_n_cop_dissociate_pages;
264
265static inline void fscache_stat(atomic_t *stat)
266{
267 atomic_inc(stat);
268}
269
270static inline void fscache_stat_d(atomic_t *stat)
271{
272 atomic_dec(stat);
273}
274
275#define __fscache_stat(stat) (stat)
276
277extern const struct file_operations fscache_stats_fops;
278#else
279
280#define __fscache_stat(stat) (NULL)
281#define fscache_stat(stat) do {} while (0)
282#define fscache_stat_d(stat) do {} while (0)
283#endif
284
285/*
286 * raise an event on an object
287 * - if the event is not masked for that object, then the object is
288 * queued for attention by the thread pool.
289 */
290static inline void fscache_raise_event(struct fscache_object *object,
291 unsigned event)
292{
293 BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
294 if (!test_and_set_bit(event, &object->events) &&
295 test_bit(event, &object->event_mask))
296 fscache_enqueue_object(object);
297}
298
299/*
300 * drop a reference to a cookie
301 */
302static inline void fscache_cookie_put(struct fscache_cookie *cookie)
303{
304 BUG_ON(atomic_read(&cookie->usage) <= 0);
305 if (atomic_dec_and_test(&cookie->usage))
306 __fscache_cookie_put(cookie);
307}
308
309/*
310 * get an extra reference to a netfs retrieval context
311 */
312static inline
313void *fscache_get_context(struct fscache_cookie *cookie, void *context)
314{
315 if (cookie->def->get_context)
316 cookie->def->get_context(cookie->netfs_data, context);
317 return context;
318}
319
320/*
321 * release a reference to a netfs retrieval context
322 */
323static inline
324void fscache_put_context(struct fscache_cookie *cookie, void *context)
325{
326 if (cookie->def->put_context)
327 cookie->def->put_context(cookie->netfs_data, context);
328}
329
330/*****************************************************************************/
331/*
332 * debug tracing
333 */
334#define dbgprintk(FMT, ...) \
335 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
336
337#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
338#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
339#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
340
341#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
342
343#ifdef __KDEBUG
344#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
345#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
346#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
347
348#elif defined(CONFIG_FSCACHE_DEBUG)
349#define _enter(FMT, ...) \
350do { \
351 if (__do_kdebug(ENTER)) \
352 kenter(FMT, ##__VA_ARGS__); \
353} while (0)
354
355#define _leave(FMT, ...) \
356do { \
357 if (__do_kdebug(LEAVE)) \
358 kleave(FMT, ##__VA_ARGS__); \
359} while (0)
360
361#define _debug(FMT, ...) \
362do { \
363 if (__do_kdebug(DEBUG)) \
364 kdebug(FMT, ##__VA_ARGS__); \
365} while (0)
366
367#else
368#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
369#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
370#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
371#endif
372
373/*
374 * determine whether a particular optional debugging point should be logged
375 * - we need to go through three steps to persuade cpp to correctly join the
376 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
377 */
378#define ____do_kdebug(LEVEL, POINT) \
379 unlikely((fscache_debug & \
380 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
381#define ___do_kdebug(LEVEL, POINT) \
382 ____do_kdebug(LEVEL, POINT)
383#define __do_kdebug(POINT) \
384 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
385
386#define FSCACHE_DEBUG_CACHE 0
387#define FSCACHE_DEBUG_COOKIE 1
388#define FSCACHE_DEBUG_PAGE 2
389#define FSCACHE_DEBUG_OPERATION 3
390
391#define FSCACHE_POINT_ENTER 1
392#define FSCACHE_POINT_LEAVE 2
393#define FSCACHE_POINT_DEBUG 4
394
395#ifndef FSCACHE_DEBUG_LEVEL
396#define FSCACHE_DEBUG_LEVEL CACHE
397#endif
398
399/*
400 * assertions
401 */
402#if 1 /* defined(__KDEBUGALL) */
403
404#define ASSERT(X) \
405do { \
406 if (unlikely(!(X))) { \
407 printk(KERN_ERR "\n"); \
408 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
409 BUG(); \
410 } \
411} while (0)
412
413#define ASSERTCMP(X, OP, Y) \
414do { \
415 if (unlikely(!((X) OP (Y)))) { \
416 printk(KERN_ERR "\n"); \
417 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
418 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
419 (unsigned long)(X), (unsigned long)(Y)); \
420 BUG(); \
421 } \
422} while (0)
423
424#define ASSERTIF(C, X) \
425do { \
426 if (unlikely((C) && !(X))) { \
427 printk(KERN_ERR "\n"); \
428 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
429 BUG(); \
430 } \
431} while (0)
432
433#define ASSERTIFCMP(C, X, OP, Y) \
434do { \
435 if (unlikely((C) && !((X) OP (Y)))) { \
436 printk(KERN_ERR "\n"); \
437 printk(KERN_ERR "FS-Cache: Assertion failed\n"); \
438 printk(KERN_ERR "%lx " #OP " %lx is false\n", \
439 (unsigned long)(X), (unsigned long)(Y)); \
440 BUG(); \
441 } \
442} while (0)
443
444#else
445
446#define ASSERT(X) do {} while (0)
447#define ASSERTCMP(X, OP, Y) do {} while (0)
448#define ASSERTIF(C, X) do {} while (0)
449#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
450
451#endif /* assert or not */