1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* Internal definitions for FS-Cache
3 *
4 * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#ifdef pr_fmt
9#undef pr_fmt
10#endif
11
12#define pr_fmt(fmt) "FS-Cache: " fmt
13
14#include <linux/slab.h>
15#include <linux/fscache-cache.h>
16#include <trace/events/fscache.h>
17#include <linux/sched.h>
18#include <linux/seq_file.h>
19
20/*
21 * cache.c
22 */
23#ifdef CONFIG_PROC_FS
24extern const struct seq_operations fscache_caches_seq_ops;
25#endif
26bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
27void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
28struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache);
29void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where);
30
31static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache)
32{
33 return smp_load_acquire(&cache->state);
34}
35
36static inline bool fscache_cache_is_live(const struct fscache_cache *cache)
37{
38 return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE;
39}
40
41static inline void fscache_set_cache_state(struct fscache_cache *cache,
42 enum fscache_cache_state new_state)
43{
44 smp_store_release(&cache->state, new_state);
45
46}
47
48static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache,
49 enum fscache_cache_state old_state,
50 enum fscache_cache_state new_state)
51{
52 return try_cmpxchg_release(&cache->state, &old_state, new_state);
53}
54
55/*
56 * cookie.c
57 */
58extern struct kmem_cache *fscache_cookie_jar;
59#ifdef CONFIG_PROC_FS
60extern const struct seq_operations fscache_cookies_seq_ops;
61#endif
62extern struct timer_list fscache_cookie_lru_timer;
63
64extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
65extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
66 enum fscache_access_trace why);
67
68static inline void fscache_see_cookie(struct fscache_cookie *cookie,
69 enum fscache_cookie_trace where)
70{
71 trace_fscache_cookie(cookie_debug_id: cookie->debug_id, ref: refcount_read(r: &cookie->ref),
72 where);
73}
74
75/*
76 * main.c
77 */
78extern unsigned fscache_debug;
79
80extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len);
81
82/*
83 * proc.c
84 */
85#ifdef CONFIG_PROC_FS
86extern int __init fscache_proc_init(void);
87extern void fscache_proc_cleanup(void);
88#else
89#define fscache_proc_init() (0)
90#define fscache_proc_cleanup() do {} while (0)
91#endif
92
93/*
94 * stats.c
95 */
96#ifdef CONFIG_FSCACHE_STATS
97extern atomic_t fscache_n_volumes;
98extern atomic_t fscache_n_volumes_collision;
99extern atomic_t fscache_n_volumes_nomem;
100extern atomic_t fscache_n_cookies;
101extern atomic_t fscache_n_cookies_lru;
102extern atomic_t fscache_n_cookies_lru_expired;
103extern atomic_t fscache_n_cookies_lru_removed;
104extern atomic_t fscache_n_cookies_lru_dropped;
105
106extern atomic_t fscache_n_acquires;
107extern atomic_t fscache_n_acquires_ok;
108extern atomic_t fscache_n_acquires_oom;
109
110extern atomic_t fscache_n_invalidates;
111
112extern atomic_t fscache_n_relinquishes;
113extern atomic_t fscache_n_relinquishes_retire;
114extern atomic_t fscache_n_relinquishes_dropped;
115
116extern atomic_t fscache_n_resizes;
117extern atomic_t fscache_n_resizes_null;
118
119static inline void fscache_stat(atomic_t *stat)
120{
121 atomic_inc(v: stat);
122}
123
124static inline void fscache_stat_d(atomic_t *stat)
125{
126 atomic_dec(v: stat);
127}
128
129#define __fscache_stat(stat) (stat)
130
131int fscache_stats_show(struct seq_file *m, void *v);
132#else
133
134#define __fscache_stat(stat) (NULL)
135#define fscache_stat(stat) do {} while (0)
136#define fscache_stat_d(stat) do {} while (0)
137#endif
138
139/*
140 * volume.c
141 */
142#ifdef CONFIG_PROC_FS
143extern const struct seq_operations fscache_volumes_seq_ops;
144#endif
145
146struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
147 enum fscache_volume_trace where);
148void fscache_put_volume(struct fscache_volume *volume,
149 enum fscache_volume_trace where);
150bool fscache_begin_volume_access(struct fscache_volume *volume,
151 struct fscache_cookie *cookie,
152 enum fscache_access_trace why);
153void fscache_create_volume(struct fscache_volume *volume, bool wait);
154
155
156/*****************************************************************************/
157/*
158 * debug tracing
159 */
160#define dbgprintk(FMT, ...) \
161 printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
162
163#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
164#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
165#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
166
167#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
168
169#ifdef __KDEBUG
170#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
171#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
172#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
173
174#elif defined(CONFIG_FSCACHE_DEBUG)
175#define _enter(FMT, ...) \
176do { \
177 if (__do_kdebug(ENTER)) \
178 kenter(FMT, ##__VA_ARGS__); \
179} while (0)
180
181#define _leave(FMT, ...) \
182do { \
183 if (__do_kdebug(LEAVE)) \
184 kleave(FMT, ##__VA_ARGS__); \
185} while (0)
186
187#define _debug(FMT, ...) \
188do { \
189 if (__do_kdebug(DEBUG)) \
190 kdebug(FMT, ##__VA_ARGS__); \
191} while (0)
192
193#else
194#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
195#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
196#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
197#endif
198
199/*
200 * determine whether a particular optional debugging point should be logged
201 * - we need to go through three steps to persuade cpp to correctly join the
202 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
203 */
204#define ____do_kdebug(LEVEL, POINT) \
205 unlikely((fscache_debug & \
206 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
207#define ___do_kdebug(LEVEL, POINT) \
208 ____do_kdebug(LEVEL, POINT)
209#define __do_kdebug(POINT) \
210 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
211
212#define FSCACHE_DEBUG_CACHE 0
213#define FSCACHE_DEBUG_COOKIE 1
214#define FSCACHE_DEBUG_OBJECT 2
215#define FSCACHE_DEBUG_OPERATION 3
216
217#define FSCACHE_POINT_ENTER 1
218#define FSCACHE_POINT_LEAVE 2
219#define FSCACHE_POINT_DEBUG 4
220
221#ifndef FSCACHE_DEBUG_LEVEL
222#define FSCACHE_DEBUG_LEVEL CACHE
223#endif
224
225/*
226 * assertions
227 */
228#if 1 /* defined(__KDEBUGALL) */
229
230#define ASSERT(X) \
231do { \
232 if (unlikely(!(X))) { \
233 pr_err("\n"); \
234 pr_err("Assertion failed\n"); \
235 BUG(); \
236 } \
237} while (0)
238
239#define ASSERTCMP(X, OP, Y) \
240do { \
241 if (unlikely(!((X) OP (Y)))) { \
242 pr_err("\n"); \
243 pr_err("Assertion failed\n"); \
244 pr_err("%lx " #OP " %lx is false\n", \
245 (unsigned long)(X), (unsigned long)(Y)); \
246 BUG(); \
247 } \
248} while (0)
249
250#define ASSERTIF(C, X) \
251do { \
252 if (unlikely((C) && !(X))) { \
253 pr_err("\n"); \
254 pr_err("Assertion failed\n"); \
255 BUG(); \
256 } \
257} while (0)
258
259#define ASSERTIFCMP(C, X, OP, Y) \
260do { \
261 if (unlikely((C) && !((X) OP (Y)))) { \
262 pr_err("\n"); \
263 pr_err("Assertion failed\n"); \
264 pr_err("%lx " #OP " %lx is false\n", \
265 (unsigned long)(X), (unsigned long)(Y)); \
266 BUG(); \
267 } \
268} while (0)
269
270#else
271
272#define ASSERT(X) do {} while (0)
273#define ASSERTCMP(X, OP, Y) do {} while (0)
274#define ASSERTIF(C, X) do {} while (0)
275#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
276
277#endif /* assert or not */
278

source code of linux/fs/fscache/internal.h