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