summaryrefslogtreecommitdiff
path: root/fs/cachefiles/internal.h
blob: e57ce5ef875c524a5ad0427f6965522e2c6e6797 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/* SPDX-License-Identifier: GPL-2.0-or-later */
/* General netfs cache on cache files internal defs
 *
 * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#ifdef pr_fmt
#undef pr_fmt
#endif

#define pr_fmt(fmt) "CacheFiles: " fmt


#include <linux/fscache-cache.h>
#include <linux/cred.h>
#include <linux/security.h>

struct cachefiles_cache;
struct cachefiles_object;

/*
 * Data file records.
 */
struct cachefiles_object {
	int				debug_id;	/* debugging ID */
};

/*
 * Cache files cache definition
 */
struct cachefiles_cache {
	struct fscache_cache		*cache;		/* Cache cookie */
	struct vfsmount			*mnt;		/* mountpoint holding the cache */
	struct file			*cachefilesd;	/* manager daemon handle */
	const struct cred		*cache_cred;	/* security override for accessing cache */
	struct mutex			daemon_mutex;	/* command serialisation mutex */
	wait_queue_head_t		daemon_pollwq;	/* poll waitqueue for daemon */
	atomic_t			gravecounter;	/* graveyard uniquifier */
	atomic_t			f_released;	/* number of objects released lately */
	atomic_long_t			b_released;	/* number of blocks released lately */
	unsigned			frun_percent;	/* when to stop culling (% files) */
	unsigned			fcull_percent;	/* when to start culling (% files) */
	unsigned			fstop_percent;	/* when to stop allocating (% files) */
	unsigned			brun_percent;	/* when to stop culling (% blocks) */
	unsigned			bcull_percent;	/* when to start culling (% blocks) */
	unsigned			bstop_percent;	/* when to stop allocating (% blocks) */
	unsigned			bsize;		/* cache's block size */
	unsigned			bshift;		/* min(ilog2(PAGE_SIZE / bsize), 0) */
	uint64_t			frun;		/* when to stop culling */
	uint64_t			fcull;		/* when to start culling */
	uint64_t			fstop;		/* when to stop allocating */
	sector_t			brun;		/* when to stop culling */
	sector_t			bcull;		/* when to start culling */
	sector_t			bstop;		/* when to stop allocating */
	unsigned long			flags;
#define CACHEFILES_READY		0	/* T if cache prepared */
#define CACHEFILES_DEAD			1	/* T if cache dead */
#define CACHEFILES_CULLING		2	/* T if cull engaged */
#define CACHEFILES_STATE_CHANGED	3	/* T if state changed (poll trigger) */
	char				*rootdirname;	/* name of cache root directory */
	char				*secctx;	/* LSM security context */
	char				*tag;		/* cache binding tag */
};

#include <trace/events/cachefiles.h>

/*
 * error_inject.c
 */
#ifdef CONFIG_CACHEFILES_ERROR_INJECTION
extern unsigned int cachefiles_error_injection_state;
extern int cachefiles_register_error_injection(void);
extern void cachefiles_unregister_error_injection(void);

#else
#define cachefiles_error_injection_state 0

static inline int cachefiles_register_error_injection(void)
{
	return 0;
}

static inline void cachefiles_unregister_error_injection(void)
{
}
#endif


static inline int cachefiles_inject_read_error(void)
{
	return cachefiles_error_injection_state & 2 ? -EIO : 0;
}

static inline int cachefiles_inject_write_error(void)
{
	return cachefiles_error_injection_state & 2 ? -EIO :
		cachefiles_error_injection_state & 1 ? -ENOSPC :
		0;
}

static inline int cachefiles_inject_remove_error(void)
{
	return cachefiles_error_injection_state & 2 ? -EIO : 0;
}

/*
 * security.c
 */
extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
					       struct dentry *root,
					       const struct cred **_saved_cred);

static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
					   const struct cred **_saved_cred)
{
	*_saved_cred = override_creds(cache->cache_cred);
}

static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
					 const struct cred *saved_cred)
{
	revert_creds(saved_cred);
}

/*
 * Error handling
 */
#define cachefiles_io_error(___cache, FMT, ...)		\
do {							\
	pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__);	\
	fscache_io_error((___cache)->cache);		\
	set_bit(CACHEFILES_DEAD, &(___cache)->flags);	\
} while (0)


/*
 * Debug tracing
 */
extern unsigned cachefiles_debug;
#define CACHEFILES_DEBUG_KENTER	1
#define CACHEFILES_DEBUG_KLEAVE	2
#define CACHEFILES_DEBUG_KDEBUG	4

#define dbgprintk(FMT, ...) \
	printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)

#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)


#if defined(__KDEBUG)
#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)

#elif defined(CONFIG_CACHEFILES_DEBUG)
#define _enter(FMT, ...)				\
do {							\
	if (cachefiles_debug & CACHEFILES_DEBUG_KENTER)	\
		kenter(FMT, ##__VA_ARGS__);		\
} while (0)

#define _leave(FMT, ...)				\
do {							\
	if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE)	\
		kleave(FMT, ##__VA_ARGS__);		\
} while (0)

#define _debug(FMT, ...)				\
do {							\
	if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG)	\
		kdebug(FMT, ##__VA_ARGS__);		\
} while (0)

#else
#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
#endif

#if 1 /* defined(__KDEBUGALL) */

#define ASSERT(X)							\
do {									\
	if (unlikely(!(X))) {						\
		pr_err("\n");						\
		pr_err("Assertion failed\n");		\
		BUG();							\
	}								\
} while (0)

#define ASSERTCMP(X, OP, Y)						\
do {									\
	if (unlikely(!((X) OP (Y)))) {					\
		pr_err("\n");						\
		pr_err("Assertion failed\n");		\
		pr_err("%lx " #OP " %lx is false\n",			\
		       (unsigned long)(X), (unsigned long)(Y));		\
		BUG();							\
	}								\
} while (0)

#define ASSERTIF(C, X)							\
do {									\
	if (unlikely((C) && !(X))) {					\
		pr_err("\n");						\
		pr_err("Assertion failed\n");		\
		BUG();							\
	}								\
} while (0)

#define ASSERTIFCMP(C, X, OP, Y)					\
do {									\
	if (unlikely((C) && !((X) OP (Y)))) {				\
		pr_err("\n");						\
		pr_err("Assertion failed\n");		\
		pr_err("%lx " #OP " %lx is false\n",			\
		       (unsigned long)(X), (unsigned long)(Y));		\
		BUG();							\
	}								\
} while (0)

#else

#define ASSERT(X)			do {} while (0)
#define ASSERTCMP(X, OP, Y)		do {} while (0)
#define ASSERTIF(C, X)			do {} while (0)
#define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)

#endif