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, &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(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