tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* Internal definitions for FS-Cache
3 *
4 * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8/*
9 * Lock order, in the order in which multiple locks should be obtained:
10 * - fscache_addremove_sem
11 * - cookie->lock
12 * - cookie->parent->lock
13 * - cache->object_list_lock
14 * - object->lock
15 * - object->parent->lock
16 * - cookie->stores_lock
17 * - fscache_thread_lock
18 *
19 */
20
21#ifdef pr_fmt
22#undef pr_fmt
23#endif
24
25#define pr_fmt(fmt) "FS-Cache: " fmt
26
27#include <linux/fscache-cache.h>
28#include <trace/events/fscache.h>
29#include <linux/sched.h>
30#include <linux/seq_file.h>
31
32#define FSCACHE_MIN_THREADS 4
33#define FSCACHE_MAX_THREADS 32
34
35/*
36 * cache.c
37 */
38extern struct list_head fscache_cache_list;
39extern struct rw_semaphore fscache_addremove_sem;
40
41extern struct fscache_cache *fscache_select_cache_for_object(
42 struct fscache_cookie *);
43
44/*
45 * cookie.c
46 */
47extern struct kmem_cache *fscache_cookie_jar;
48
49extern void fscache_free_cookie(struct fscache_cookie *);
50extern struct fscache_cookie *fscache_alloc_cookie(struct fscache_cookie *,
51 const struct fscache_cookie_def *,
52 const void *, size_t,
53 const void *, size_t,
54 void *, loff_t);
55extern struct fscache_cookie *fscache_hash_cookie(struct fscache_cookie *);
56extern void fscache_cookie_put(struct fscache_cookie *,
57 enum fscache_cookie_trace);
58
59/*
60 * fsdef.c
61 */
62extern struct fscache_cookie fscache_fsdef_index;
63extern struct fscache_cookie_def fscache_fsdef_netfs_def;
64
65/*
66 * histogram.c
67 */
68#ifdef CONFIG_FSCACHE_HISTOGRAM
69extern atomic_t fscache_obj_instantiate_histogram[HZ];
70extern atomic_t fscache_objs_histogram[HZ];
71extern atomic_t fscache_ops_histogram[HZ];
72extern atomic_t fscache_retrieval_delay_histogram[HZ];
73extern atomic_t fscache_retrieval_histogram[HZ];
74
75static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
76{
77 unsigned long jif = jiffies - start_jif;
78 if (jif >= HZ)
79 jif = HZ - 1;
80 atomic_inc(&histogram[jif]);
81}
82
83extern const struct seq_operations fscache_histogram_ops;
84
85#else
86#define fscache_hist(hist, start_jif) do {} while (0)
87#endif
88
89/*
90 * main.c
91 */
92extern unsigned fscache_defer_lookup;
93extern unsigned fscache_defer_create;
94extern unsigned fscache_debug;
95extern struct kobject *fscache_root;
96extern struct workqueue_struct *fscache_object_wq;
97extern struct workqueue_struct *fscache_op_wq;
98DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
99
100static inline bool fscache_object_congested(void)
101{
102 return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
103}
104
105/*
106 * object.c
107 */
108extern void fscache_enqueue_object(struct fscache_object *);
109
110/*
111 * object-list.c
112 */
113#ifdef CONFIG_FSCACHE_OBJECT_LIST
114extern const struct proc_ops fscache_objlist_proc_ops;
115
116extern void fscache_objlist_add(struct fscache_object *);
117extern void fscache_objlist_remove(struct fscache_object *);
118#else
119#define fscache_objlist_add(object) do {} while(0)
120#define fscache_objlist_remove(object) do {} while(0)
121#endif
122
123/*
124 * operation.c
125 */
126extern int fscache_submit_exclusive_op(struct fscache_object *,
127 struct fscache_operation *);
128extern int fscache_submit_op(struct fscache_object *,
129 struct fscache_operation *);
130extern int fscache_cancel_op(struct fscache_operation *, bool);
131extern void fscache_cancel_all_ops(struct fscache_object *);
132extern void fscache_abort_object(struct fscache_object *);
133extern void fscache_start_operations(struct fscache_object *);
134extern void fscache_operation_gc(struct work_struct *);
135
136/*
137 * page.c
138 */
139extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
140extern int fscache_wait_for_operation_activation(struct fscache_object *,
141 struct fscache_operation *,
142 atomic_t *,
143 atomic_t *);
144extern void fscache_invalidate_writes(struct fscache_cookie *);
145
146/*
147 * proc.c
148 */
149#ifdef CONFIG_PROC_FS
150extern int __init fscache_proc_init(void);
151extern void fscache_proc_cleanup(void);
152#else
153#define fscache_proc_init() (0)
154#define fscache_proc_cleanup() do {} while (0)
155#endif
156
157/*
158 * stats.c
159 */
160#ifdef CONFIG_FSCACHE_STATS
161extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
162extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
163
164extern atomic_t fscache_n_op_pend;
165extern atomic_t fscache_n_op_run;
166extern atomic_t fscache_n_op_enqueue;
167extern atomic_t fscache_n_op_deferred_release;
168extern atomic_t fscache_n_op_initialised;
169extern atomic_t fscache_n_op_release;
170extern atomic_t fscache_n_op_gc;
171extern atomic_t fscache_n_op_cancelled;
172extern atomic_t fscache_n_op_rejected;
173
174extern atomic_t fscache_n_attr_changed;
175extern atomic_t fscache_n_attr_changed_ok;
176extern atomic_t fscache_n_attr_changed_nobufs;
177extern atomic_t fscache_n_attr_changed_nomem;
178extern atomic_t fscache_n_attr_changed_calls;
179
180extern atomic_t fscache_n_allocs;
181extern atomic_t fscache_n_allocs_ok;
182extern atomic_t fscache_n_allocs_wait;
183extern atomic_t fscache_n_allocs_nobufs;
184extern atomic_t fscache_n_allocs_intr;
185extern atomic_t fscache_n_allocs_object_dead;
186extern atomic_t fscache_n_alloc_ops;
187extern atomic_t fscache_n_alloc_op_waits;
188
189extern atomic_t fscache_n_retrievals;
190extern atomic_t fscache_n_retrievals_ok;
191extern atomic_t fscache_n_retrievals_wait;
192extern atomic_t fscache_n_retrievals_nodata;
193extern atomic_t fscache_n_retrievals_nobufs;
194extern atomic_t fscache_n_retrievals_intr;
195extern atomic_t fscache_n_retrievals_nomem;
196extern atomic_t fscache_n_retrievals_object_dead;
197extern atomic_t fscache_n_retrieval_ops;
198extern atomic_t fscache_n_retrieval_op_waits;
199
200extern atomic_t fscache_n_stores;
201extern atomic_t fscache_n_stores_ok;
202extern atomic_t fscache_n_stores_again;
203extern atomic_t fscache_n_stores_nobufs;
204extern atomic_t fscache_n_stores_oom;
205extern atomic_t fscache_n_store_ops;
206extern atomic_t fscache_n_store_calls;
207extern atomic_t fscache_n_store_pages;
208extern atomic_t fscache_n_store_radix_deletes;
209extern atomic_t fscache_n_store_pages_over_limit;
210
211extern atomic_t fscache_n_store_vmscan_not_storing;
212extern atomic_t fscache_n_store_vmscan_gone;
213extern atomic_t fscache_n_store_vmscan_busy;
214extern atomic_t fscache_n_store_vmscan_cancelled;
215extern atomic_t fscache_n_store_vmscan_wait;
216
217extern atomic_t fscache_n_marks;
218extern atomic_t fscache_n_uncaches;
219
220extern atomic_t fscache_n_acquires;
221extern atomic_t fscache_n_acquires_null;
222extern atomic_t fscache_n_acquires_no_cache;
223extern atomic_t fscache_n_acquires_ok;
224extern atomic_t fscache_n_acquires_nobufs;
225extern atomic_t fscache_n_acquires_oom;
226
227extern atomic_t fscache_n_invalidates;
228extern atomic_t fscache_n_invalidates_run;
229
230extern atomic_t fscache_n_updates;
231extern atomic_t fscache_n_updates_null;
232extern atomic_t fscache_n_updates_run;
233
234extern atomic_t fscache_n_relinquishes;
235extern atomic_t fscache_n_relinquishes_null;
236extern atomic_t fscache_n_relinquishes_waitcrt;
237extern atomic_t fscache_n_relinquishes_retire;
238
239extern atomic_t fscache_n_cookie_index;
240extern atomic_t fscache_n_cookie_data;
241extern atomic_t fscache_n_cookie_special;
242
243extern atomic_t fscache_n_object_alloc;
244extern atomic_t fscache_n_object_no_alloc;
245extern atomic_t fscache_n_object_lookups;
246extern atomic_t fscache_n_object_lookups_negative;
247extern atomic_t fscache_n_object_lookups_positive;
248extern atomic_t fscache_n_object_lookups_timed_out;
249extern atomic_t fscache_n_object_created;
250extern atomic_t fscache_n_object_avail;
251extern atomic_t fscache_n_object_dead;
252
253extern atomic_t fscache_n_checkaux_none;
254extern atomic_t fscache_n_checkaux_okay;
255extern atomic_t fscache_n_checkaux_update;
256extern atomic_t fscache_n_checkaux_obsolete;
257
258extern atomic_t fscache_n_cop_alloc_object;
259extern atomic_t fscache_n_cop_lookup_object;
260extern atomic_t fscache_n_cop_lookup_complete;
261extern atomic_t fscache_n_cop_grab_object;
262extern atomic_t fscache_n_cop_invalidate_object;
263extern atomic_t fscache_n_cop_update_object;
264extern atomic_t fscache_n_cop_drop_object;
265extern atomic_t fscache_n_cop_put_object;
266extern atomic_t fscache_n_cop_sync_cache;
267extern atomic_t fscache_n_cop_attr_changed;
268extern atomic_t fscache_n_cop_read_or_alloc_page;
269extern atomic_t fscache_n_cop_read_or_alloc_pages;
270extern atomic_t fscache_n_cop_allocate_page;
271extern atomic_t fscache_n_cop_allocate_pages;
272extern atomic_t fscache_n_cop_write_page;
273extern atomic_t fscache_n_cop_uncache_page;
274extern atomic_t fscache_n_cop_dissociate_pages;
275
276extern atomic_t fscache_n_cache_no_space_reject;
277extern atomic_t fscache_n_cache_stale_objects;
278extern atomic_t fscache_n_cache_retired_objects;
279extern atomic_t fscache_n_cache_culled_objects;
280
281static inline void fscache_stat(atomic_t *stat)
282{
283 atomic_inc(stat);
284}
285
286static inline void fscache_stat_d(atomic_t *stat)
287{
288 atomic_dec(stat);
289}
290
291#define __fscache_stat(stat) (stat)
292
293int fscache_stats_show(struct seq_file *m, void *v);
294#else
295
296#define __fscache_stat(stat) (NULL)
297#define fscache_stat(stat) do {} while (0)
298#define fscache_stat_d(stat) do {} while (0)
299#endif
300
301/*
302 * raise an event on an object
303 * - if the event is not masked for that object, then the object is
304 * queued for attention by the thread pool.
305 */
306static inline void fscache_raise_event(struct fscache_object *object,
307 unsigned event)
308{
309 BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
310#if 0
311 printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
312 object->debug_id, object->event_mask, (1 << event));
313#endif
314 if (!test_and_set_bit(event, &object->events) &&
315 test_bit(event, &object->event_mask))
316 fscache_enqueue_object(object);
317}
318
319static inline void fscache_cookie_get(struct fscache_cookie *cookie,
320 enum fscache_cookie_trace where)
321{
322 int usage = atomic_inc_return(&cookie->usage);
323
324 trace_fscache_cookie(cookie, where, usage);
325}
326
327/*
328 * get an extra reference to a netfs retrieval context
329 */
330static inline
331void *fscache_get_context(struct fscache_cookie *cookie, void *context)
332{
333 if (cookie->def->get_context)
334 cookie->def->get_context(cookie->netfs_data, context);
335 return context;
336}
337
338/*
339 * release a reference to a netfs retrieval context
340 */
341static inline
342void fscache_put_context(struct fscache_cookie *cookie, void *context)
343{
344 if (cookie->def->put_context)
345 cookie->def->put_context(cookie->netfs_data, context);
346}
347
348/*
349 * Update the auxiliary data on a cookie.
350 */
351static inline
352void fscache_update_aux(struct fscache_cookie *cookie, const void *aux_data)
353{
354 void *p;
355
356 if (!aux_data)
357 return;
358 if (cookie->aux_len <= sizeof(cookie->inline_aux))
359 p = cookie->inline_aux;
360 else
361 p = cookie->aux;
362
363 if (memcmp(p, aux_data, cookie->aux_len) != 0) {
364 memcpy(p, aux_data, cookie->aux_len);
365 set_bit(FSCACHE_COOKIE_AUX_UPDATED, &cookie->flags);
366 }
367}
368
369/*****************************************************************************/
370/*
371 * debug tracing
372 */
373#define dbgprintk(FMT, ...) \
374 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
375
376#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
377#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
378#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
379
380#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
381
382#ifdef __KDEBUG
383#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
384#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
385#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
386
387#elif defined(CONFIG_FSCACHE_DEBUG)
388#define _enter(FMT, ...) \
389do { \
390 if (__do_kdebug(ENTER)) \
391 kenter(FMT, ##__VA_ARGS__); \
392} while (0)
393
394#define _leave(FMT, ...) \
395do { \
396 if (__do_kdebug(LEAVE)) \
397 kleave(FMT, ##__VA_ARGS__); \
398} while (0)
399
400#define _debug(FMT, ...) \
401do { \
402 if (__do_kdebug(DEBUG)) \
403 kdebug(FMT, ##__VA_ARGS__); \
404} while (0)
405
406#else
407#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
408#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
409#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
410#endif
411
412/*
413 * determine whether a particular optional debugging point should be logged
414 * - we need to go through three steps to persuade cpp to correctly join the
415 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
416 */
417#define ____do_kdebug(LEVEL, POINT) \
418 unlikely((fscache_debug & \
419 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
420#define ___do_kdebug(LEVEL, POINT) \
421 ____do_kdebug(LEVEL, POINT)
422#define __do_kdebug(POINT) \
423 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
424
425#define FSCACHE_DEBUG_CACHE 0
426#define FSCACHE_DEBUG_COOKIE 1
427#define FSCACHE_DEBUG_PAGE 2
428#define FSCACHE_DEBUG_OPERATION 3
429
430#define FSCACHE_POINT_ENTER 1
431#define FSCACHE_POINT_LEAVE 2
432#define FSCACHE_POINT_DEBUG 4
433
434#ifndef FSCACHE_DEBUG_LEVEL
435#define FSCACHE_DEBUG_LEVEL CACHE
436#endif
437
438/*
439 * assertions
440 */
441#if 1 /* defined(__KDEBUGALL) */
442
443#define ASSERT(X) \
444do { \
445 if (unlikely(!(X))) { \
446 pr_err("\n"); \
447 pr_err("Assertion failed\n"); \
448 BUG(); \
449 } \
450} while (0)
451
452#define ASSERTCMP(X, OP, Y) \
453do { \
454 if (unlikely(!((X) OP (Y)))) { \
455 pr_err("\n"); \
456 pr_err("Assertion failed\n"); \
457 pr_err("%lx " #OP " %lx is false\n", \
458 (unsigned long)(X), (unsigned long)(Y)); \
459 BUG(); \
460 } \
461} while (0)
462
463#define ASSERTIF(C, X) \
464do { \
465 if (unlikely((C) && !(X))) { \
466 pr_err("\n"); \
467 pr_err("Assertion failed\n"); \
468 BUG(); \
469 } \
470} while (0)
471
472#define ASSERTIFCMP(C, X, OP, Y) \
473do { \
474 if (unlikely((C) && !((X) OP (Y)))) { \
475 pr_err("\n"); \
476 pr_err("Assertion failed\n"); \
477 pr_err("%lx " #OP " %lx is false\n", \
478 (unsigned long)(X), (unsigned long)(Y)); \
479 BUG(); \
480 } \
481} while (0)
482
483#else
484
485#define ASSERT(X) do {} while (0)
486#define ASSERTCMP(X, OP, Y) do {} while (0)
487#define ASSERTIF(C, X) do {} while (0)
488#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
489
490#endif /* assert or not */