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
24 extern const struct seq_operations fscache_caches_seq_ops;
25 #endif
26 bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
27 void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
28 struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache);
29 void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where);
30 
fscache_cache_state(const struct fscache_cache * cache)31 static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache)
32 {
33 	return smp_load_acquire(&cache->state);
34 }
35 
fscache_cache_is_live(const struct fscache_cache * cache)36 static inline bool fscache_cache_is_live(const struct fscache_cache *cache)
37 {
38 	return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE;
39 }
40 
fscache_set_cache_state(struct fscache_cache * cache,enum fscache_cache_state new_state)41 static 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 
fscache_set_cache_state_maybe(struct fscache_cache * cache,enum fscache_cache_state old_state,enum fscache_cache_state new_state)48 static 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  */
58 extern struct kmem_cache *fscache_cookie_jar;
59 #ifdef CONFIG_PROC_FS
60 extern const struct seq_operations fscache_cookies_seq_ops;
61 #endif
62 extern struct timer_list fscache_cookie_lru_timer;
63 
64 extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
65 extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
66 					enum fscache_access_trace why);
67 
fscache_see_cookie(struct fscache_cookie * cookie,enum fscache_cookie_trace where)68 static inline void fscache_see_cookie(struct fscache_cookie *cookie,
69 				      enum fscache_cookie_trace where)
70 {
71 	trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
72 			     where);
73 }
74 
75 /*
76  * main.c
77  */
78 extern unsigned fscache_debug;
79 
80 extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len);
81 
82 /*
83  * proc.c
84  */
85 #ifdef CONFIG_PROC_FS
86 extern int __init fscache_proc_init(void);
87 extern 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
97 extern atomic_t fscache_n_volumes;
98 extern atomic_t fscache_n_volumes_collision;
99 extern atomic_t fscache_n_volumes_nomem;
100 extern atomic_t fscache_n_cookies;
101 extern atomic_t fscache_n_cookies_lru;
102 extern atomic_t fscache_n_cookies_lru_expired;
103 extern atomic_t fscache_n_cookies_lru_removed;
104 extern atomic_t fscache_n_cookies_lru_dropped;
105 
106 extern atomic_t fscache_n_acquires;
107 extern atomic_t fscache_n_acquires_ok;
108 extern atomic_t fscache_n_acquires_oom;
109 
110 extern atomic_t fscache_n_invalidates;
111 
112 extern atomic_t fscache_n_relinquishes;
113 extern atomic_t fscache_n_relinquishes_retire;
114 extern atomic_t fscache_n_relinquishes_dropped;
115 
116 extern atomic_t fscache_n_resizes;
117 extern atomic_t fscache_n_resizes_null;
118 
fscache_stat(atomic_t * stat)119 static inline void fscache_stat(atomic_t *stat)
120 {
121 	atomic_inc(stat);
122 }
123 
fscache_stat_d(atomic_t * stat)124 static inline void fscache_stat_d(atomic_t *stat)
125 {
126 	atomic_dec(stat);
127 }
128 
129 #define __fscache_stat(stat) (stat)
130 
131 int 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
143 extern const struct seq_operations fscache_volumes_seq_ops;
144 #endif
145 
146 struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
147 					  enum fscache_volume_trace where);
148 void fscache_put_volume(struct fscache_volume *volume,
149 			enum fscache_volume_trace where);
150 bool fscache_begin_volume_access(struct fscache_volume *volume,
151 				 struct fscache_cookie *cookie,
152 				 enum fscache_access_trace why);
153 void 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, ...)			\
176 do {						\
177 	if (__do_kdebug(ENTER))			\
178 		kenter(FMT, ##__VA_ARGS__);	\
179 } while (0)
180 
181 #define _leave(FMT, ...)			\
182 do {						\
183 	if (__do_kdebug(LEAVE))			\
184 		kleave(FMT, ##__VA_ARGS__);	\
185 } while (0)
186 
187 #define _debug(FMT, ...)			\
188 do {						\
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)							\
231 do {									\
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)						\
240 do {									\
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)							\
251 do {									\
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)					\
260 do {									\
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