summaryrefslogtreecommitdiffstats
path: root/fs/cachefiles/internal.h
blob: 54a4fcd679ede5a7113ff1f7d812b09a7feb1c4b (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
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
/* General netfs cache on cache files internal defs
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#ifdef pr_fmt
#undef pr_fmt
#endif

#define pr_fmt(fmt) "CacheFiles: " fmt


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

struct cachefiles_cache;
struct cachefiles_object;

extern unsigned cachefiles_debug;
#define CACHEFILES_DEBUG_KENTER	1
#define CACHEFILES_DEBUG_KLEAVE	2
#define CACHEFILES_DEBUG_KDEBUG	4

#define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC)

/*
 * node records
 */
struct cachefiles_object {
	struct fscache_object		fscache;	/* fscache handle */
	struct cachefiles_lookup_data	*lookup_data;	/* cached lookup data */
	struct dentry			*dentry;	/* the file/dir representing this object */
	struct dentry			*backer;	/* backing file */
	loff_t				i_size;		/* object size */
	unsigned long			flags;
#define CACHEFILES_OBJECT_ACTIVE	0		/* T if marked active */
	atomic_t			usage;		/* object usage count */
	uint8_t				type;		/* object type */
	uint8_t				new;		/* T if object new */
	spinlock_t			work_lock;
	struct rb_node			active_node;	/* link in active tree (dentry is key) */
};

extern struct kmem_cache *cachefiles_object_jar;

/*
 * Cache files cache definition
 */
struct cachefiles_cache {
	struct fscache_cache		cache;		/* FS-Cache record */
	struct vfsmount			*mnt;		/* mountpoint holding the cache */
	struct dentry			*graveyard;	/* directory into which dead objects go */
	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 */
	struct rb_root			active_nodes;	/* active nodes (can't be culled) */
	rwlock_t			active_lock;	/* lock for active_nodes */
	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 */
};

/*
 * backing file read tracking
 */
struct cachefiles_one_read {
	wait_queue_entry_t			monitor;	/* link into monitored waitqueue */
	struct page			*back_page;	/* backing file page we're waiting for */
	struct page			*netfs_page;	/* netfs page we're going to fill */
	struct fscache_retrieval	*op;		/* retrieval op covering this */
	struct list_head		op_link;	/* link in op's todo list */
};

/*
 * backing file write tracking
 */
struct cachefiles_one_write {
	struct page			*netfs_page;	/* netfs page to copy */
	struct cachefiles_object	*object;
	struct list_head		obj_link;	/* link in object's lists */
	fscache_rw_complete_t		end_io_func;
	void				*context;
};

/*
 * auxiliary data xattr buffer
 */
struct cachefiles_xattr {
	uint16_t			len;
	uint8_t				type;
	uint8_t				data[];
};

/*
 * note change of state for daemon
 */
static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
{
	set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
	wake_up_all(&cache->daemon_pollwq);
}

/*
 * bind.c
 */
extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);

/*
 * daemon.c
 */
extern const struct file_operations cachefiles_daemon_fops;

extern int cachefiles_has_space(struct cachefiles_cache *cache,
				unsigned fnr, unsigned bnr);

/*
 * interface.c
 */
extern const struct fscache_cache_ops cachefiles_cache_ops;

/*
 * key.c
 */
extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);

/*
 * namei.c
 */
extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
					    struct cachefiles_object *object,
					    blkcnt_t i_blocks);
extern int cachefiles_delete_object(struct cachefiles_cache *cache,
				    struct cachefiles_object *object);
extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
				     struct cachefiles_object *object,
				     const char *key,
				     struct cachefiles_xattr *auxdata);
extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
					       struct dentry *dir,
					       const char *name);

extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
			   char *filename);

extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
				   struct dentry *dir, char *filename);

/*
 * proc.c
 */
#ifdef CONFIG_CACHEFILES_HISTOGRAM
extern atomic_t cachefiles_lookup_histogram[HZ];
extern atomic_t cachefiles_mkdir_histogram[HZ];
extern atomic_t cachefiles_create_histogram[HZ];

extern int __init cachefiles_proc_init(void);
extern void cachefiles_proc_cleanup(void);
static inline
void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
{
	unsigned long jif = jiffies - start_jif;
	if (jif >= HZ)
		jif = HZ - 1;
	atomic_inc(&histogram[jif]);
}

#else
#define cachefiles_proc_init()		(0)
#define cachefiles_proc_cleanup()	do {} while (0)
#define cachefiles_hist(hist, start_jif) do {} while (0)
#endif

/*
 * rdwr.c
 */
extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
					 struct page *, gfp_t);
extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
					  struct list_head *, unsigned *,
					  gfp_t);
extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
				    gfp_t);
extern int cachefiles_allocate_pages(struct fscache_retrieval *,
				     struct list_head *, unsigned *, gfp_t);
extern int cachefiles_write_page(struct fscache_storage *, struct page *);
extern void cachefiles_uncache_page(struct fscache_object *, struct page *);

/*
 * 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);
}

/*
 * xattr.c
 */
extern int cachefiles_check_object_type(struct cachefiles_object *object);
extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
				       struct cachefiles_xattr *auxdata);
extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
					  struct cachefiles_xattr *auxdata);
extern int cachefiles_check_auxdata(struct cachefiles_object *object);
extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
					 struct cachefiles_xattr *auxdata);
extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
					  struct dentry *dentry);


/*
 * 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)

#define cachefiles_io_error_obj(object, FMT, ...)			\
do {									\
	struct cachefiles_cache *___cache;				\
									\
	___cache = container_of((object)->fscache.cache,		\
				struct cachefiles_cache, cache);	\
	cachefiles_io_error(___cache, FMT, ##__VA_ARGS__);		\
} while (0)


/*
 * debug tracing
 */
#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