1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* General netfs cache on cache files internal defs
3 *
4 * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells ([email protected])
6 */
7
8 #ifdef pr_fmt
9 #undef pr_fmt
10 #endif
11
12 #define pr_fmt(fmt) "CacheFiles: " fmt
13
14
15 #include <linux/fscache-cache.h>
16 #include <linux/cred.h>
17 #include <linux/security.h>
18 #include <linux/xarray.h>
19 #include <linux/cachefiles.h>
20
21 #define CACHEFILES_DIO_BLOCK_SIZE 4096
22
23 struct cachefiles_cache;
24 struct cachefiles_object;
25
26 enum cachefiles_content {
27 /* These values are saved on disk */
28 CACHEFILES_CONTENT_NO_DATA = 0, /* No content stored */
29 CACHEFILES_CONTENT_SINGLE = 1, /* Content is monolithic, all is present */
30 CACHEFILES_CONTENT_ALL = 2, /* Content is all present, no map */
31 CACHEFILES_CONTENT_BACKFS_MAP = 3, /* Content is piecemeal, mapped through backing fs */
32 CACHEFILES_CONTENT_DIRTY = 4, /* Content is dirty (only seen on disk) */
33 nr__cachefiles_content
34 };
35
36 /*
37 * Cached volume representation.
38 */
39 struct cachefiles_volume {
40 struct cachefiles_cache *cache;
41 struct list_head cache_link; /* Link in cache->volumes */
42 struct fscache_volume *vcookie; /* The netfs's representation */
43 struct dentry *dentry; /* The volume dentry */
44 struct dentry *fanout[256]; /* Fanout subdirs */
45 };
46
47 enum cachefiles_object_state {
48 CACHEFILES_ONDEMAND_OBJSTATE_CLOSE, /* Anonymous fd closed by daemon or initial state */
49 CACHEFILES_ONDEMAND_OBJSTATE_OPEN, /* Anonymous fd associated with object is available */
50 CACHEFILES_ONDEMAND_OBJSTATE_REOPENING, /* Object that was closed and is being reopened. */
51 CACHEFILES_ONDEMAND_OBJSTATE_DROPPING, /* Object is being dropped. */
52 };
53
54 struct cachefiles_ondemand_info {
55 struct work_struct ondemand_work;
56 int ondemand_id;
57 enum cachefiles_object_state state;
58 struct cachefiles_object *object;
59 spinlock_t lock;
60 };
61
62 /*
63 * Backing file state.
64 */
65 struct cachefiles_object {
66 struct fscache_cookie *cookie; /* Netfs data storage object cookie */
67 struct cachefiles_volume *volume; /* Cache volume that holds this object */
68 struct list_head cache_link; /* Link in cache->*_list */
69 struct file *file; /* The file representing this object */
70 char *d_name; /* Backing file name */
71 int debug_id;
72 spinlock_t lock;
73 refcount_t ref;
74 u8 d_name_len; /* Length of filename */
75 enum cachefiles_content content_info:8; /* Info about content presence */
76 unsigned long flags;
77 #define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */
78 #ifdef CONFIG_CACHEFILES_ONDEMAND
79 struct cachefiles_ondemand_info *ondemand;
80 #endif
81 };
82
83 #define CACHEFILES_ONDEMAND_ID_CLOSED -1
84
85 /*
86 * Cache files cache definition
87 */
88 struct cachefiles_cache {
89 struct fscache_cache *cache; /* Cache cookie */
90 struct vfsmount *mnt; /* mountpoint holding the cache */
91 struct dentry *store; /* Directory into which live objects go */
92 struct dentry *graveyard; /* directory into which dead objects go */
93 struct file *cachefilesd; /* manager daemon handle */
94 struct list_head volumes; /* List of volume objects */
95 struct list_head object_list; /* List of active objects */
96 spinlock_t object_list_lock; /* Lock for volumes and object_list */
97 const struct cred *cache_cred; /* security override for accessing cache */
98 struct mutex daemon_mutex; /* command serialisation mutex */
99 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
100 atomic_t gravecounter; /* graveyard uniquifier */
101 atomic_t f_released; /* number of objects released lately */
102 atomic_long_t b_released; /* number of blocks released lately */
103 atomic_long_t b_writing; /* Number of blocks being written */
104 unsigned frun_percent; /* when to stop culling (% files) */
105 unsigned fcull_percent; /* when to start culling (% files) */
106 unsigned fstop_percent; /* when to stop allocating (% files) */
107 unsigned brun_percent; /* when to stop culling (% blocks) */
108 unsigned bcull_percent; /* when to start culling (% blocks) */
109 unsigned bstop_percent; /* when to stop allocating (% blocks) */
110 unsigned bsize; /* cache's block size */
111 unsigned bshift; /* ilog2(bsize) */
112 uint64_t frun; /* when to stop culling */
113 uint64_t fcull; /* when to start culling */
114 uint64_t fstop; /* when to stop allocating */
115 sector_t brun; /* when to stop culling */
116 sector_t bcull; /* when to start culling */
117 sector_t bstop; /* when to stop allocating */
118 unsigned long flags;
119 #define CACHEFILES_READY 0 /* T if cache prepared */
120 #define CACHEFILES_DEAD 1 /* T if cache dead */
121 #define CACHEFILES_CULLING 2 /* T if cull engaged */
122 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
123 #define CACHEFILES_ONDEMAND_MODE 4 /* T if in on-demand read mode */
124 char *rootdirname; /* name of cache root directory */
125 char *tag; /* cache binding tag */
126 refcount_t unbind_pincount;/* refcount to do daemon unbind */
127 struct xarray reqs; /* xarray of pending on-demand requests */
128 unsigned long req_id_next;
129 struct xarray ondemand_ids; /* xarray for ondemand_id allocation */
130 u32 ondemand_id_next;
131 u32 msg_id_next;
132 u32 secid; /* LSM security id */
133 bool have_secid; /* whether "secid" was set */
134 };
135
cachefiles_in_ondemand_mode(struct cachefiles_cache * cache)136 static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache)
137 {
138 return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) &&
139 test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags);
140 }
141
142 struct cachefiles_req {
143 struct cachefiles_object *object;
144 struct completion done;
145 refcount_t ref;
146 int error;
147 struct cachefiles_msg msg;
148 };
149
150 #define CACHEFILES_REQ_NEW XA_MARK_1
151
152 #include <trace/events/cachefiles.h>
153
154 static inline
cachefiles_cres_file(struct netfs_cache_resources * cres)155 struct file *cachefiles_cres_file(struct netfs_cache_resources *cres)
156 {
157 return cres->cache_priv2;
158 }
159
160 static inline
cachefiles_cres_object(struct netfs_cache_resources * cres)161 struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres)
162 {
163 return fscache_cres_cookie(cres)->cache_priv;
164 }
165
166 /*
167 * note change of state for daemon
168 */
cachefiles_state_changed(struct cachefiles_cache * cache)169 static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
170 {
171 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
172 wake_up_all(&cache->daemon_pollwq);
173 }
174
175 /*
176 * cache.c
177 */
178 extern int cachefiles_add_cache(struct cachefiles_cache *cache);
179 extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache);
180
181 enum cachefiles_has_space_for {
182 cachefiles_has_space_check,
183 cachefiles_has_space_for_write,
184 cachefiles_has_space_for_create,
185 };
186 extern int cachefiles_has_space(struct cachefiles_cache *cache,
187 unsigned fnr, unsigned bnr,
188 enum cachefiles_has_space_for reason);
189
190 /*
191 * daemon.c
192 */
193 extern const struct file_operations cachefiles_daemon_fops;
194 extern void cachefiles_flush_reqs(struct cachefiles_cache *cache);
195 extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache);
196 extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache);
197
198 /*
199 * error_inject.c
200 */
201 #ifdef CONFIG_CACHEFILES_ERROR_INJECTION
202 extern unsigned int cachefiles_error_injection_state;
203 extern int cachefiles_register_error_injection(void);
204 extern void cachefiles_unregister_error_injection(void);
205
206 #else
207 #define cachefiles_error_injection_state 0
208
cachefiles_register_error_injection(void)209 static inline int cachefiles_register_error_injection(void)
210 {
211 return 0;
212 }
213
cachefiles_unregister_error_injection(void)214 static inline void cachefiles_unregister_error_injection(void)
215 {
216 }
217 #endif
218
219
cachefiles_inject_read_error(void)220 static inline int cachefiles_inject_read_error(void)
221 {
222 return cachefiles_error_injection_state & 2 ? -EIO : 0;
223 }
224
cachefiles_inject_write_error(void)225 static inline int cachefiles_inject_write_error(void)
226 {
227 return cachefiles_error_injection_state & 2 ? -EIO :
228 cachefiles_error_injection_state & 1 ? -ENOSPC :
229 0;
230 }
231
cachefiles_inject_remove_error(void)232 static inline int cachefiles_inject_remove_error(void)
233 {
234 return cachefiles_error_injection_state & 2 ? -EIO : 0;
235 }
236
237 /*
238 * interface.c
239 */
240 extern const struct fscache_cache_ops cachefiles_cache_ops;
241 extern void cachefiles_see_object(struct cachefiles_object *object,
242 enum cachefiles_obj_ref_trace why);
243 extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
244 enum cachefiles_obj_ref_trace why);
245 extern void cachefiles_put_object(struct cachefiles_object *object,
246 enum cachefiles_obj_ref_trace why);
247
248 /*
249 * io.c
250 */
251 extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,
252 enum fscache_want_state want_state);
253 extern int __cachefiles_prepare_write(struct cachefiles_object *object,
254 struct file *file,
255 loff_t *_start, size_t *_len, size_t upper_len,
256 bool no_space_allocated_yet);
257 extern int __cachefiles_write(struct cachefiles_object *object,
258 struct file *file,
259 loff_t start_pos,
260 struct iov_iter *iter,
261 netfs_io_terminated_t term_func,
262 void *term_func_priv);
263
264 /*
265 * key.c
266 */
267 extern bool cachefiles_cook_key(struct cachefiles_object *object);
268
269 /*
270 * main.c
271 */
272 extern struct kmem_cache *cachefiles_object_jar;
273
274 /*
275 * namei.c
276 */
277 extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
278 struct file *file);
279 extern int cachefiles_bury_object(struct cachefiles_cache *cache,
280 struct cachefiles_object *object,
281 struct dentry *dir,
282 struct dentry *rep,
283 enum fscache_why_object_killed why);
284 extern int cachefiles_delete_object(struct cachefiles_object *object,
285 enum fscache_why_object_killed why);
286 extern bool cachefiles_look_up_object(struct cachefiles_object *object);
287 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
288 struct dentry *dir,
289 const char *name,
290 bool *_is_new);
291 extern void cachefiles_put_directory(struct dentry *dir);
292
293 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
294 char *filename);
295
296 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
297 struct dentry *dir, char *filename);
298 extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object);
299 extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
300 struct cachefiles_object *object);
301
302 /*
303 * ondemand.c
304 */
305 #ifdef CONFIG_CACHEFILES_ONDEMAND
306 extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
307 char __user *_buffer, size_t buflen);
308
309 extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache,
310 char *args);
311
312 extern int cachefiles_ondemand_restore(struct cachefiles_cache *cache,
313 char *args);
314
315 extern int cachefiles_ondemand_init_object(struct cachefiles_object *object);
316 extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object);
317
318 extern int cachefiles_ondemand_read(struct cachefiles_object *object,
319 loff_t pos, size_t len);
320
321 extern int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj,
322 struct cachefiles_volume *volume);
323 extern void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj);
324
325 #define CACHEFILES_OBJECT_STATE_FUNCS(_state, _STATE) \
326 static inline bool \
327 cachefiles_ondemand_object_is_##_state(const struct cachefiles_object *object) \
328 { \
329 return object->ondemand->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
330 } \
331 \
332 static inline void \
333 cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \
334 { \
335 object->ondemand->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \
336 }
337
338 CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN);
339 CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE);
340 CACHEFILES_OBJECT_STATE_FUNCS(reopening, REOPENING);
341 CACHEFILES_OBJECT_STATE_FUNCS(dropping, DROPPING);
342
cachefiles_ondemand_is_reopening_read(struct cachefiles_req * req)343 static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req)
344 {
345 return cachefiles_ondemand_object_is_reopening(req->object) &&
346 req->msg.opcode == CACHEFILES_OP_READ;
347 }
348
349 #else
cachefiles_ondemand_daemon_read(struct cachefiles_cache * cache,char __user * _buffer,size_t buflen)350 static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache,
351 char __user *_buffer, size_t buflen)
352 {
353 return -EOPNOTSUPP;
354 }
355
cachefiles_ondemand_init_object(struct cachefiles_object * object)356 static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object)
357 {
358 return 0;
359 }
360
cachefiles_ondemand_clean_object(struct cachefiles_object * object)361 static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
362 {
363 }
364
cachefiles_ondemand_read(struct cachefiles_object * object,loff_t pos,size_t len)365 static inline int cachefiles_ondemand_read(struct cachefiles_object *object,
366 loff_t pos, size_t len)
367 {
368 return -EOPNOTSUPP;
369 }
370
cachefiles_ondemand_init_obj_info(struct cachefiles_object * obj,struct cachefiles_volume * volume)371 static inline int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj,
372 struct cachefiles_volume *volume)
373 {
374 return 0;
375 }
cachefiles_ondemand_deinit_obj_info(struct cachefiles_object * obj)376 static inline void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj)
377 {
378 }
379
cachefiles_ondemand_is_reopening_read(struct cachefiles_req * req)380 static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req)
381 {
382 return false;
383 }
384 #endif
385
386 /*
387 * security.c
388 */
389 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
390 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
391 struct dentry *root,
392 const struct cred **_saved_cred);
393
cachefiles_begin_secure(struct cachefiles_cache * cache,const struct cred ** _saved_cred)394 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
395 const struct cred **_saved_cred)
396 {
397 *_saved_cred = override_creds(cache->cache_cred);
398 }
399
cachefiles_end_secure(struct cachefiles_cache * cache,const struct cred * saved_cred)400 static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
401 const struct cred *saved_cred)
402 {
403 revert_creds(saved_cred);
404 }
405
406 /*
407 * volume.c
408 */
409 void cachefiles_acquire_volume(struct fscache_volume *volume);
410 void cachefiles_free_volume(struct fscache_volume *volume);
411 void cachefiles_withdraw_volume(struct cachefiles_volume *volume);
412
413 /*
414 * xattr.c
415 */
416 extern int cachefiles_set_object_xattr(struct cachefiles_object *object);
417 extern int cachefiles_check_auxdata(struct cachefiles_object *object,
418 struct file *file);
419 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
420 struct cachefiles_object *object,
421 struct dentry *dentry);
422 extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);
423 extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume);
424 extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume);
425
426 /*
427 * Error handling
428 */
429 #define cachefiles_io_error(___cache, FMT, ...) \
430 do { \
431 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \
432 fscache_io_error((___cache)->cache); \
433 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
434 if (cachefiles_in_ondemand_mode(___cache)) \
435 cachefiles_flush_reqs(___cache); \
436 } while (0)
437
438 #define cachefiles_io_error_obj(object, FMT, ...) \
439 do { \
440 struct cachefiles_cache *___cache; \
441 \
442 ___cache = (object)->volume->cache; \
443 cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \
444 (object)->debug_id); \
445 } while (0)
446
447
448 /*
449 * Debug tracing
450 */
451 extern unsigned cachefiles_debug;
452 #define CACHEFILES_DEBUG_KENTER 1
453 #define CACHEFILES_DEBUG_KLEAVE 2
454 #define CACHEFILES_DEBUG_KDEBUG 4
455
456 #define dbgprintk(FMT, ...) \
457 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
458
459 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
460 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
461 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
462
463
464 #if defined(__KDEBUG)
465 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
466 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
467 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
468
469 #elif defined(CONFIG_CACHEFILES_DEBUG)
470 #define _enter(FMT, ...) \
471 do { \
472 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
473 kenter(FMT, ##__VA_ARGS__); \
474 } while (0)
475
476 #define _leave(FMT, ...) \
477 do { \
478 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
479 kleave(FMT, ##__VA_ARGS__); \
480 } while (0)
481
482 #define _debug(FMT, ...) \
483 do { \
484 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
485 kdebug(FMT, ##__VA_ARGS__); \
486 } while (0)
487
488 #else
489 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
490 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
491 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
492 #endif
493
494 #if 1 /* defined(__KDEBUGALL) */
495
496 #define ASSERT(X) \
497 do { \
498 if (unlikely(!(X))) { \
499 pr_err("\n"); \
500 pr_err("Assertion failed\n"); \
501 BUG(); \
502 } \
503 } while (0)
504
505 #define ASSERTCMP(X, OP, Y) \
506 do { \
507 if (unlikely(!((X) OP (Y)))) { \
508 pr_err("\n"); \
509 pr_err("Assertion failed\n"); \
510 pr_err("%lx " #OP " %lx is false\n", \
511 (unsigned long)(X), (unsigned long)(Y)); \
512 BUG(); \
513 } \
514 } while (0)
515
516 #define ASSERTIF(C, X) \
517 do { \
518 if (unlikely((C) && !(X))) { \
519 pr_err("\n"); \
520 pr_err("Assertion failed\n"); \
521 BUG(); \
522 } \
523 } while (0)
524
525 #define ASSERTIFCMP(C, X, OP, Y) \
526 do { \
527 if (unlikely((C) && !((X) OP (Y)))) { \
528 pr_err("\n"); \
529 pr_err("Assertion failed\n"); \
530 pr_err("%lx " #OP " %lx is false\n", \
531 (unsigned long)(X), (unsigned long)(Y)); \
532 BUG(); \
533 } \
534 } while (0)
535
536 #else
537
538 #define ASSERT(X) do {} while (0)
539 #define ASSERTCMP(X, OP, Y) do {} while (0)
540 #define ASSERTIF(C, X) do {} while (0)
541 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
542
543 #endif
544