summaryrefslogtreecommitdiff
path: root/fs/cachefiles/internal.h
blob: 6cba2c6de2f963d762da94aea13f37dedd33349a (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
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
/* 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>
#include <linux/xarray.h>
#include <linux/cachefiles.h>

#define CACHEFILES_DIO_BLOCK_SIZE 4096

struct cachefiles_cache;
struct cachefiles_object;

enum cachefiles_content {
	/* These values are saved on disk */
	CACHEFILES_CONTENT_NO_DATA	= 0, /* No content stored */
	CACHEFILES_CONTENT_SINGLE	= 1, /* Content is monolithic, all is present */
	CACHEFILES_CONTENT_ALL		= 2, /* Content is all present, no map */
	CACHEFILES_CONTENT_BACKFS_MAP	= 3, /* Content is piecemeal, mapped through backing fs */
	CACHEFILES_CONTENT_DIRTY	= 4, /* Content is dirty (only seen on disk) */
	nr__cachefiles_content
};

/*
 * Cached volume representation.
 */
struct cachefiles_volume {
	struct cachefiles_cache		*cache;
	struct list_head		cache_link;	/* Link in cache->volumes */
	struct fscache_volume		*vcookie;	/* The netfs's representation */
	struct dentry			*dentry;	/* The volume dentry */
	struct dentry			*fanout[256];	/* Fanout subdirs */
};

/*
 * Backing file state.
 */
struct cachefiles_object {
	struct fscache_cookie		*cookie;	/* Netfs data storage object cookie */
	struct cachefiles_volume	*volume;	/* Cache volume that holds this object */
	struct list_head		cache_link;	/* Link in cache->*_list */
	struct file			*file;		/* The file representing this object */
	char				*d_name;	/* Backing file name */
	int				debug_id;
	spinlock_t			lock;
	refcount_t			ref;
	u8				d_name_len;	/* Length of filename */
	enum cachefiles_content		content_info:8;	/* Info about content presence */
	unsigned long			flags;
#define CACHEFILES_OBJECT_USING_TMPFILE	0		/* Have an unlinked tmpfile */
#ifdef CONFIG_CACHEFILES_ONDEMAND
	int				ondemand_id;
#endif
};

#define CACHEFILES_ONDEMAND_ID_CLOSED	-1

/*
 * Cache files cache definition
 */
struct cachefiles_cache {
	struct fscache_cache		*cache;		/* Cache cookie */
	struct vfsmount			*mnt;		/* mountpoint holding the cache */
	struct dentry			*store;		/* Directory into which live objects go */
	struct dentry			*graveyard;	/* directory into which dead objects go */
	struct file			*cachefilesd;	/* manager daemon handle */
	struct list_head		volumes;	/* List of volume objects */
	struct list_head		object_list;	/* List of active objects */
	spinlock_t			object_list_lock; /* Lock for volumes and object_list */
	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 */
	atomic_long_t			b_writing;	/* Number of blocks being written */
	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;		/* ilog2(bsize) */
	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) */
#define CACHEFILES_ONDEMAND_MODE	4	/* T if in on-demand read mode */
	char				*rootdirname;	/* name of cache root directory */
	char				*secctx;	/* LSM security context */
	char				*tag;		/* cache binding tag */
	refcount_t			unbind_pincount;/* refcount to do daemon unbind */
	struct xarray			reqs;		/* xarray of pending on-demand requests */
	struct xarray			ondemand_ids;	/* xarray for ondemand_id allocation */
	u32				ondemand_id_next;
};

static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache)
{
	return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) &&
		test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags);
}

struct cachefiles_req {
	struct cachefiles_object *object;
	struct completion done;
	int error;
	struct cachefiles_msg msg;
};

#define CACHEFILES_REQ_NEW	XA_MARK_1

#include <trace/events/cachefiles.h>

static inline
struct file *cachefiles_cres_file(struct netfs_cache_resources *cres)
{
	return cres->cache_priv2;
}

static inline
struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres)
{
	return fscache_cres_cookie(cres)->cache_priv;
}

/*
 * 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);
}

/*
 * cache.c
 */
extern int cachefiles_add_cache(struct cachefiles_cache *cache);
extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache);

enum cachefiles_has_space_for {
	cachefiles_has_space_check,
	cachefiles_has_space_for_write,
	cachefiles_has_space_for_create,
};
extern int cachefiles_has_space(struct cachefiles_cache *cache,
				unsigned fnr, unsigned bnr,
				enum cachefiles_has_space_for reason);

/*
 * daemon.c
 */
extern const struct file_operations cachefiles_daemon_fops;
extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache);
extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache);

/*
 * 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;
}

/*
 * interface.c
 */
extern const struct fscache_cache_ops cachefiles_cache_ops;
extern void cachefiles_see_object(struct cachefiles_object *object,
				  enum cachefiles_obj_ref_trace why);
extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
							enum cachefiles_obj_ref_trace why);
extern void cachefiles_put_object(struct cachefiles_object *object,
				  enum cachefiles_obj_ref_trace why);

/*
 * io.c
 */
extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,
				       enum fscache_want_state want_state);
extern int __cachefiles_prepare_write(struct cachefiles_object *object,
				      struct file *file,
				      loff_t *_start, size_t *_len,
				      bool no_space_allocated_yet);
extern int __cachefiles_write(struct cachefiles_object *object,
			      struct file *file,
			      loff_t start_pos,
			      struct iov_iter *iter,
			      netfs_io_terminated_t term_func,
			      void *term_func_priv);

/*
 * key.c
 */
extern bool cachefiles_cook_key(struct cachefiles_object *object);

/*
 * main.c
 */
extern struct kmem_cache *cachefiles_object_jar;

/*
 * namei.c
 */
extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
					   struct file *file);
extern int cachefiles_bury_object(struct cachefiles_cache *cache,
				  struct cachefiles_object *object,
				  struct dentry *dir,
				  struct dentry *rep,
				  enum fscache_why_object_killed why);
extern int cachefiles_delete_object(struct cachefiles_object *object,
				    enum fscache_why_object_killed why);
extern bool cachefiles_look_up_object(struct cachefiles_object *object);
extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
					       struct dentry *dir,
					       const char *name,
					       bool *_is_new);
extern void cachefiles_put_directory(struct dentry *dir);

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);
extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object);
extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
				      struct cachefiles_object *object);

/*
 * ondemand.c
 */
#ifdef CONFIG_CACHEFILES_ONDEMAND
extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
					char __user *_buffer, size_t buflen);

extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache,
				     char *args);

extern int cachefiles_ondemand_init_object(struct cachefiles_object *object);
extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object);

extern int cachefiles_ondemand_read(struct cachefiles_object *object,
				    loff_t pos, size_t len);

#else
static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
					char __user *_buffer, size_t buflen)
{
	return -EOPNOTSUPP;
}

static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object)
{
	return 0;
}

static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
{
}

static inline int cachefiles_ondemand_read(struct cachefiles_object *object,
					   loff_t pos, size_t len)
{
	return -EOPNOTSUPP;
}
#endif

/*
 * 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);
}

/*
 * volume.c
 */
void cachefiles_acquire_volume(struct fscache_volume *volume);
void cachefiles_free_volume(struct fscache_volume *volume);
void cachefiles_withdraw_volume(struct cachefiles_volume *volume);

/*
 * xattr.c
 */
extern int cachefiles_set_object_xattr(struct cachefiles_object *object);
extern int cachefiles_check_auxdata(struct cachefiles_object *object,
				    struct file *file);
extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
					  struct cachefiles_object *object,
					  struct dentry *dentry);
extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);
extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume);
extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume);

/*
 * 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 = (object)->volume->cache;				\
	cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__,	\
			    (object)->debug_id);			\
} 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