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 | /* |
48 | * Backing file state. |
49 | */ |
50 | struct cachefiles_object { |
51 | struct fscache_cookie *cookie; /* Netfs data storage object cookie */ |
52 | struct cachefiles_volume *volume; /* Cache volume that holds this object */ |
53 | struct list_head cache_link; /* Link in cache->*_list */ |
54 | struct file *file; /* The file representing this object */ |
55 | char *d_name; /* Backing file name */ |
56 | int debug_id; |
57 | spinlock_t lock; |
58 | refcount_t ref; |
59 | u8 d_name_len; /* Length of filename */ |
60 | enum cachefiles_content content_info:8; /* Info about content presence */ |
61 | unsigned long flags; |
62 | #define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */ |
63 | #ifdef CONFIG_CACHEFILES_ONDEMAND |
64 | int ondemand_id; |
65 | #endif |
66 | }; |
67 | |
68 | #define CACHEFILES_ONDEMAND_ID_CLOSED -1 |
69 | |
70 | /* |
71 | * Cache files cache definition |
72 | */ |
73 | struct cachefiles_cache { |
74 | struct fscache_cache *cache; /* Cache cookie */ |
75 | struct vfsmount *mnt; /* mountpoint holding the cache */ |
76 | struct dentry *store; /* Directory into which live objects go */ |
77 | struct dentry *graveyard; /* directory into which dead objects go */ |
78 | struct file *cachefilesd; /* manager daemon handle */ |
79 | struct list_head volumes; /* List of volume objects */ |
80 | struct list_head object_list; /* List of active objects */ |
81 | spinlock_t object_list_lock; /* Lock for volumes and object_list */ |
82 | const struct cred *cache_cred; /* security override for accessing cache */ |
83 | struct mutex daemon_mutex; /* command serialisation mutex */ |
84 | wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ |
85 | atomic_t gravecounter; /* graveyard uniquifier */ |
86 | atomic_t f_released; /* number of objects released lately */ |
87 | atomic_long_t b_released; /* number of blocks released lately */ |
88 | atomic_long_t b_writing; /* Number of blocks being written */ |
89 | unsigned frun_percent; /* when to stop culling (% files) */ |
90 | unsigned fcull_percent; /* when to start culling (% files) */ |
91 | unsigned fstop_percent; /* when to stop allocating (% files) */ |
92 | unsigned brun_percent; /* when to stop culling (% blocks) */ |
93 | unsigned bcull_percent; /* when to start culling (% blocks) */ |
94 | unsigned bstop_percent; /* when to stop allocating (% blocks) */ |
95 | unsigned bsize; /* cache's block size */ |
96 | unsigned bshift; /* ilog2(bsize) */ |
97 | uint64_t frun; /* when to stop culling */ |
98 | uint64_t fcull; /* when to start culling */ |
99 | uint64_t fstop; /* when to stop allocating */ |
100 | sector_t brun; /* when to stop culling */ |
101 | sector_t bcull; /* when to start culling */ |
102 | sector_t bstop; /* when to stop allocating */ |
103 | unsigned long flags; |
104 | #define CACHEFILES_READY 0 /* T if cache prepared */ |
105 | #define CACHEFILES_DEAD 1 /* T if cache dead */ |
106 | #define CACHEFILES_CULLING 2 /* T if cull engaged */ |
107 | #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ |
108 | #define CACHEFILES_ONDEMAND_MODE 4 /* T if in on-demand read mode */ |
109 | char *rootdirname; /* name of cache root directory */ |
110 | char *secctx; /* LSM security context */ |
111 | char *tag; /* cache binding tag */ |
112 | refcount_t unbind_pincount;/* refcount to do daemon unbind */ |
113 | struct xarray reqs; /* xarray of pending on-demand requests */ |
114 | unsigned long req_id_next; |
115 | struct xarray ondemand_ids; /* xarray for ondemand_id allocation */ |
116 | u32 ondemand_id_next; |
117 | }; |
118 | |
119 | static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache) |
120 | { |
121 | return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) && |
122 | test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags); |
123 | } |
124 | |
125 | struct cachefiles_req { |
126 | struct cachefiles_object *object; |
127 | struct completion done; |
128 | int error; |
129 | struct cachefiles_msg msg; |
130 | }; |
131 | |
132 | #define CACHEFILES_REQ_NEW XA_MARK_1 |
133 | |
134 | #include <trace/events/cachefiles.h> |
135 | |
136 | static inline |
137 | struct file *cachefiles_cres_file(struct netfs_cache_resources *cres) |
138 | { |
139 | return cres->cache_priv2; |
140 | } |
141 | |
142 | static inline |
143 | struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres) |
144 | { |
145 | return fscache_cres_cookie(cres)->cache_priv; |
146 | } |
147 | |
148 | /* |
149 | * note change of state for daemon |
150 | */ |
151 | static inline void cachefiles_state_changed(struct cachefiles_cache *cache) |
152 | { |
153 | set_bit(CACHEFILES_STATE_CHANGED, addr: &cache->flags); |
154 | wake_up_all(&cache->daemon_pollwq); |
155 | } |
156 | |
157 | /* |
158 | * cache.c |
159 | */ |
160 | extern int cachefiles_add_cache(struct cachefiles_cache *cache); |
161 | extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache); |
162 | |
163 | enum cachefiles_has_space_for { |
164 | cachefiles_has_space_check, |
165 | cachefiles_has_space_for_write, |
166 | cachefiles_has_space_for_create, |
167 | }; |
168 | extern int cachefiles_has_space(struct cachefiles_cache *cache, |
169 | unsigned fnr, unsigned bnr, |
170 | enum cachefiles_has_space_for reason); |
171 | |
172 | /* |
173 | * daemon.c |
174 | */ |
175 | extern const struct file_operations cachefiles_daemon_fops; |
176 | extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache); |
177 | extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache); |
178 | |
179 | /* |
180 | * error_inject.c |
181 | */ |
182 | #ifdef CONFIG_CACHEFILES_ERROR_INJECTION |
183 | extern unsigned int cachefiles_error_injection_state; |
184 | extern int cachefiles_register_error_injection(void); |
185 | extern void cachefiles_unregister_error_injection(void); |
186 | |
187 | #else |
188 | #define cachefiles_error_injection_state 0 |
189 | |
190 | static inline int cachefiles_register_error_injection(void) |
191 | { |
192 | return 0; |
193 | } |
194 | |
195 | static inline void cachefiles_unregister_error_injection(void) |
196 | { |
197 | } |
198 | #endif |
199 | |
200 | |
201 | static inline int cachefiles_inject_read_error(void) |
202 | { |
203 | return cachefiles_error_injection_state & 2 ? -EIO : 0; |
204 | } |
205 | |
206 | static inline int cachefiles_inject_write_error(void) |
207 | { |
208 | return cachefiles_error_injection_state & 2 ? -EIO : |
209 | cachefiles_error_injection_state & 1 ? -ENOSPC : |
210 | 0; |
211 | } |
212 | |
213 | static inline int cachefiles_inject_remove_error(void) |
214 | { |
215 | return cachefiles_error_injection_state & 2 ? -EIO : 0; |
216 | } |
217 | |
218 | /* |
219 | * interface.c |
220 | */ |
221 | extern const struct fscache_cache_ops cachefiles_cache_ops; |
222 | extern void cachefiles_see_object(struct cachefiles_object *object, |
223 | enum cachefiles_obj_ref_trace why); |
224 | extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object, |
225 | enum cachefiles_obj_ref_trace why); |
226 | extern void cachefiles_put_object(struct cachefiles_object *object, |
227 | enum cachefiles_obj_ref_trace why); |
228 | |
229 | /* |
230 | * io.c |
231 | */ |
232 | extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres, |
233 | enum fscache_want_state want_state); |
234 | extern int __cachefiles_prepare_write(struct cachefiles_object *object, |
235 | struct file *file, |
236 | loff_t *_start, size_t *_len, |
237 | bool no_space_allocated_yet); |
238 | extern int __cachefiles_write(struct cachefiles_object *object, |
239 | struct file *file, |
240 | loff_t start_pos, |
241 | struct iov_iter *iter, |
242 | netfs_io_terminated_t term_func, |
243 | void *term_func_priv); |
244 | |
245 | /* |
246 | * key.c |
247 | */ |
248 | extern bool cachefiles_cook_key(struct cachefiles_object *object); |
249 | |
250 | /* |
251 | * main.c |
252 | */ |
253 | extern struct kmem_cache *cachefiles_object_jar; |
254 | |
255 | /* |
256 | * namei.c |
257 | */ |
258 | extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object, |
259 | struct file *file); |
260 | extern int cachefiles_bury_object(struct cachefiles_cache *cache, |
261 | struct cachefiles_object *object, |
262 | struct dentry *dir, |
263 | struct dentry *rep, |
264 | enum fscache_why_object_killed why); |
265 | extern int cachefiles_delete_object(struct cachefiles_object *object, |
266 | enum fscache_why_object_killed why); |
267 | extern bool cachefiles_look_up_object(struct cachefiles_object *object); |
268 | extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, |
269 | struct dentry *dir, |
270 | const char *name, |
271 | bool *_is_new); |
272 | extern void cachefiles_put_directory(struct dentry *dir); |
273 | |
274 | extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, |
275 | char *filename); |
276 | |
277 | extern int cachefiles_check_in_use(struct cachefiles_cache *cache, |
278 | struct dentry *dir, char *filename); |
279 | extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object); |
280 | extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache, |
281 | struct cachefiles_object *object); |
282 | |
283 | /* |
284 | * ondemand.c |
285 | */ |
286 | #ifdef CONFIG_CACHEFILES_ONDEMAND |
287 | extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, |
288 | char __user *_buffer, size_t buflen); |
289 | |
290 | extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache, |
291 | char *args); |
292 | |
293 | extern int cachefiles_ondemand_init_object(struct cachefiles_object *object); |
294 | extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object); |
295 | |
296 | extern int cachefiles_ondemand_read(struct cachefiles_object *object, |
297 | loff_t pos, size_t len); |
298 | |
299 | #else |
300 | static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, |
301 | char __user *_buffer, size_t buflen) |
302 | { |
303 | return -EOPNOTSUPP; |
304 | } |
305 | |
306 | static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object) |
307 | { |
308 | return 0; |
309 | } |
310 | |
311 | static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object) |
312 | { |
313 | } |
314 | |
315 | static inline int cachefiles_ondemand_read(struct cachefiles_object *object, |
316 | loff_t pos, size_t len) |
317 | { |
318 | return -EOPNOTSUPP; |
319 | } |
320 | #endif |
321 | |
322 | /* |
323 | * security.c |
324 | */ |
325 | extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); |
326 | extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, |
327 | struct dentry *root, |
328 | const struct cred **_saved_cred); |
329 | |
330 | static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, |
331 | const struct cred **_saved_cred) |
332 | { |
333 | *_saved_cred = override_creds(cache->cache_cred); |
334 | } |
335 | |
336 | static inline void cachefiles_end_secure(struct cachefiles_cache *cache, |
337 | const struct cred *saved_cred) |
338 | { |
339 | revert_creds(saved_cred); |
340 | } |
341 | |
342 | /* |
343 | * volume.c |
344 | */ |
345 | void cachefiles_acquire_volume(struct fscache_volume *volume); |
346 | void cachefiles_free_volume(struct fscache_volume *volume); |
347 | void cachefiles_withdraw_volume(struct cachefiles_volume *volume); |
348 | |
349 | /* |
350 | * xattr.c |
351 | */ |
352 | extern int cachefiles_set_object_xattr(struct cachefiles_object *object); |
353 | extern int cachefiles_check_auxdata(struct cachefiles_object *object, |
354 | struct file *file); |
355 | extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, |
356 | struct cachefiles_object *object, |
357 | struct dentry *dentry); |
358 | extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie); |
359 | extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume); |
360 | extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume); |
361 | |
362 | /* |
363 | * Error handling |
364 | */ |
365 | #define cachefiles_io_error(___cache, FMT, ...) \ |
366 | do { \ |
367 | pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ |
368 | fscache_io_error((___cache)->cache); \ |
369 | set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ |
370 | } while (0) |
371 | |
372 | #define cachefiles_io_error_obj(object, FMT, ...) \ |
373 | do { \ |
374 | struct cachefiles_cache *___cache; \ |
375 | \ |
376 | ___cache = (object)->volume->cache; \ |
377 | cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \ |
378 | (object)->debug_id); \ |
379 | } while (0) |
380 | |
381 | |
382 | /* |
383 | * Debug tracing |
384 | */ |
385 | extern unsigned cachefiles_debug; |
386 | #define CACHEFILES_DEBUG_KENTER 1 |
387 | #define CACHEFILES_DEBUG_KLEAVE 2 |
388 | #define CACHEFILES_DEBUG_KDEBUG 4 |
389 | |
390 | #define dbgprintk(FMT, ...) \ |
391 | printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) |
392 | |
393 | #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) |
394 | #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) |
395 | #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) |
396 | |
397 | |
398 | #if defined(__KDEBUG) |
399 | #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) |
400 | #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) |
401 | #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) |
402 | |
403 | #elif defined(CONFIG_CACHEFILES_DEBUG) |
404 | #define _enter(FMT, ...) \ |
405 | do { \ |
406 | if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ |
407 | kenter(FMT, ##__VA_ARGS__); \ |
408 | } while (0) |
409 | |
410 | #define _leave(FMT, ...) \ |
411 | do { \ |
412 | if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ |
413 | kleave(FMT, ##__VA_ARGS__); \ |
414 | } while (0) |
415 | |
416 | #define _debug(FMT, ...) \ |
417 | do { \ |
418 | if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ |
419 | kdebug(FMT, ##__VA_ARGS__); \ |
420 | } while (0) |
421 | |
422 | #else |
423 | #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) |
424 | #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) |
425 | #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) |
426 | #endif |
427 | |
428 | #if 1 /* defined(__KDEBUGALL) */ |
429 | |
430 | #define ASSERT(X) \ |
431 | do { \ |
432 | if (unlikely(!(X))) { \ |
433 | pr_err("\n"); \ |
434 | pr_err("Assertion failed\n"); \ |
435 | BUG(); \ |
436 | } \ |
437 | } while (0) |
438 | |
439 | #define ASSERTCMP(X, OP, Y) \ |
440 | do { \ |
441 | if (unlikely(!((X) OP (Y)))) { \ |
442 | pr_err("\n"); \ |
443 | pr_err("Assertion failed\n"); \ |
444 | pr_err("%lx " #OP " %lx is false\n", \ |
445 | (unsigned long)(X), (unsigned long)(Y)); \ |
446 | BUG(); \ |
447 | } \ |
448 | } while (0) |
449 | |
450 | #define ASSERTIF(C, X) \ |
451 | do { \ |
452 | if (unlikely((C) && !(X))) { \ |
453 | pr_err("\n"); \ |
454 | pr_err("Assertion failed\n"); \ |
455 | BUG(); \ |
456 | } \ |
457 | } while (0) |
458 | |
459 | #define ASSERTIFCMP(C, X, OP, Y) \ |
460 | do { \ |
461 | if (unlikely((C) && !((X) OP (Y)))) { \ |
462 | pr_err("\n"); \ |
463 | pr_err("Assertion failed\n"); \ |
464 | pr_err("%lx " #OP " %lx is false\n", \ |
465 | (unsigned long)(X), (unsigned long)(Y)); \ |
466 | BUG(); \ |
467 | } \ |
468 | } while (0) |
469 | |
470 | #else |
471 | |
472 | #define ASSERT(X) do {} while (0) |
473 | #define ASSERTCMP(X, OP, Y) do {} while (0) |
474 | #define ASSERTIF(C, X) do {} while (0) |
475 | #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) |
476 | |
477 | #endif |
478 | |