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 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 *secctx; /* LSM security context */ 126 char *tag; /* cache binding tag */ 127 refcount_t unbind_pincount;/* refcount to do daemon unbind */ 128 struct xarray reqs; /* xarray of pending on-demand requests */ 129 unsigned long req_id_next; 130 struct xarray ondemand_ids; /* xarray for ondemand_id allocation */ 131 u32 ondemand_id_next; 132 u32 msg_id_next; 133 }; 134 135 static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache) 136 { 137 return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) && 138 test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags); 139 } 140 141 struct cachefiles_req { 142 struct cachefiles_object *object; 143 struct completion done; 144 refcount_t ref; 145 int error; 146 struct cachefiles_msg msg; 147 }; 148 149 #define CACHEFILES_REQ_NEW XA_MARK_1 150 151 #include <trace/events/cachefiles.h> 152 153 static inline 154 struct file *cachefiles_cres_file(struct netfs_cache_resources *cres) 155 { 156 return cres->cache_priv2; 157 } 158 159 static inline 160 struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres) 161 { 162 return fscache_cres_cookie(cres)->cache_priv; 163 } 164 165 /* 166 * note change of state for daemon 167 */ 168 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 169 { 170 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 171 wake_up_all(&cache->daemon_pollwq); 172 } 173 174 /* 175 * cache.c 176 */ 177 extern int cachefiles_add_cache(struct cachefiles_cache *cache); 178 extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache); 179 180 enum cachefiles_has_space_for { 181 cachefiles_has_space_check, 182 cachefiles_has_space_for_write, 183 cachefiles_has_space_for_create, 184 }; 185 extern int cachefiles_has_space(struct cachefiles_cache *cache, 186 unsigned fnr, unsigned bnr, 187 enum cachefiles_has_space_for reason); 188 189 /* 190 * daemon.c 191 */ 192 extern const struct file_operations cachefiles_daemon_fops; 193 extern void cachefiles_flush_reqs(struct cachefiles_cache *cache); 194 extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache); 195 extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache); 196 197 /* 198 * error_inject.c 199 */ 200 #ifdef CONFIG_CACHEFILES_ERROR_INJECTION 201 extern unsigned int cachefiles_error_injection_state; 202 extern int cachefiles_register_error_injection(void); 203 extern void cachefiles_unregister_error_injection(void); 204 205 #else 206 #define cachefiles_error_injection_state 0 207 208 static inline int cachefiles_register_error_injection(void) 209 { 210 return 0; 211 } 212 213 static inline void cachefiles_unregister_error_injection(void) 214 { 215 } 216 #endif 217 218 219 static inline int cachefiles_inject_read_error(void) 220 { 221 return cachefiles_error_injection_state & 2 ? -EIO : 0; 222 } 223 224 static inline int cachefiles_inject_write_error(void) 225 { 226 return cachefiles_error_injection_state & 2 ? -EIO : 227 cachefiles_error_injection_state & 1 ? -ENOSPC : 228 0; 229 } 230 231 static inline int cachefiles_inject_remove_error(void) 232 { 233 return cachefiles_error_injection_state & 2 ? -EIO : 0; 234 } 235 236 /* 237 * interface.c 238 */ 239 extern const struct fscache_cache_ops cachefiles_cache_ops; 240 extern void cachefiles_see_object(struct cachefiles_object *object, 241 enum cachefiles_obj_ref_trace why); 242 extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object, 243 enum cachefiles_obj_ref_trace why); 244 extern void cachefiles_put_object(struct cachefiles_object *object, 245 enum cachefiles_obj_ref_trace why); 246 247 /* 248 * io.c 249 */ 250 extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres, 251 enum fscache_want_state want_state); 252 extern int __cachefiles_prepare_write(struct cachefiles_object *object, 253 struct file *file, 254 loff_t *_start, size_t *_len, size_t upper_len, 255 bool no_space_allocated_yet); 256 extern int __cachefiles_write(struct cachefiles_object *object, 257 struct file *file, 258 loff_t start_pos, 259 struct iov_iter *iter, 260 netfs_io_terminated_t term_func, 261 void *term_func_priv); 262 263 /* 264 * key.c 265 */ 266 extern bool cachefiles_cook_key(struct cachefiles_object *object); 267 268 /* 269 * main.c 270 */ 271 extern struct kmem_cache *cachefiles_object_jar; 272 273 /* 274 * namei.c 275 */ 276 extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 277 struct file *file); 278 extern int cachefiles_bury_object(struct cachefiles_cache *cache, 279 struct cachefiles_object *object, 280 struct dentry *dir, 281 struct dentry *rep, 282 enum fscache_why_object_killed why); 283 extern int cachefiles_delete_object(struct cachefiles_object *object, 284 enum fscache_why_object_killed why); 285 extern bool cachefiles_look_up_object(struct cachefiles_object *object); 286 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 287 struct dentry *dir, 288 const char *name, 289 bool *_is_new); 290 extern void cachefiles_put_directory(struct dentry *dir); 291 292 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 293 char *filename); 294 295 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 296 struct dentry *dir, char *filename); 297 extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object); 298 extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache, 299 struct cachefiles_object *object); 300 301 /* 302 * ondemand.c 303 */ 304 #ifdef CONFIG_CACHEFILES_ONDEMAND 305 extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, 306 char __user *_buffer, size_t buflen); 307 308 extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache, 309 char *args); 310 311 extern int cachefiles_ondemand_restore(struct cachefiles_cache *cache, 312 char *args); 313 314 extern int cachefiles_ondemand_init_object(struct cachefiles_object *object); 315 extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object); 316 317 extern int cachefiles_ondemand_read(struct cachefiles_object *object, 318 loff_t pos, size_t len); 319 320 extern int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj, 321 struct cachefiles_volume *volume); 322 extern void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj); 323 324 #define CACHEFILES_OBJECT_STATE_FUNCS(_state, _STATE) \ 325 static inline bool \ 326 cachefiles_ondemand_object_is_##_state(const struct cachefiles_object *object) \ 327 { \ 328 return object->ondemand->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \ 329 } \ 330 \ 331 static inline void \ 332 cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \ 333 { \ 334 object->ondemand->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \ 335 } 336 337 CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN); 338 CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE); 339 CACHEFILES_OBJECT_STATE_FUNCS(reopening, REOPENING); 340 CACHEFILES_OBJECT_STATE_FUNCS(dropping, DROPPING); 341 342 static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req) 343 { 344 return cachefiles_ondemand_object_is_reopening(req->object) && 345 req->msg.opcode == CACHEFILES_OP_READ; 346 } 347 348 #else 349 static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, 350 char __user *_buffer, size_t buflen) 351 { 352 return -EOPNOTSUPP; 353 } 354 355 static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object) 356 { 357 return 0; 358 } 359 360 static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object) 361 { 362 } 363 364 static inline int cachefiles_ondemand_read(struct cachefiles_object *object, 365 loff_t pos, size_t len) 366 { 367 return -EOPNOTSUPP; 368 } 369 370 static inline int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj, 371 struct cachefiles_volume *volume) 372 { 373 return 0; 374 } 375 static inline void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj) 376 { 377 } 378 379 static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req) 380 { 381 return false; 382 } 383 #endif 384 385 /* 386 * security.c 387 */ 388 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 389 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 390 struct dentry *root, 391 const struct cred **_saved_cred); 392 393 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 394 const struct cred **_saved_cred) 395 { 396 *_saved_cred = override_creds(cache->cache_cred); 397 } 398 399 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 400 const struct cred *saved_cred) 401 { 402 revert_creds(saved_cred); 403 } 404 405 /* 406 * volume.c 407 */ 408 void cachefiles_acquire_volume(struct fscache_volume *volume); 409 void cachefiles_free_volume(struct fscache_volume *volume); 410 void cachefiles_withdraw_volume(struct cachefiles_volume *volume); 411 412 /* 413 * xattr.c 414 */ 415 extern int cachefiles_set_object_xattr(struct cachefiles_object *object); 416 extern int cachefiles_check_auxdata(struct cachefiles_object *object, 417 struct file *file); 418 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 419 struct cachefiles_object *object, 420 struct dentry *dentry); 421 extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie); 422 extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume); 423 extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume); 424 425 /* 426 * Error handling 427 */ 428 #define cachefiles_io_error(___cache, FMT, ...) \ 429 do { \ 430 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 431 fscache_io_error((___cache)->cache); \ 432 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 433 if (cachefiles_in_ondemand_mode(___cache)) \ 434 cachefiles_flush_reqs(___cache); \ 435 } while (0) 436 437 #define cachefiles_io_error_obj(object, FMT, ...) \ 438 do { \ 439 struct cachefiles_cache *___cache; \ 440 \ 441 ___cache = (object)->volume->cache; \ 442 cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \ 443 (object)->debug_id); \ 444 } while (0) 445 446 447 /* 448 * Debug tracing 449 */ 450 extern unsigned cachefiles_debug; 451 #define CACHEFILES_DEBUG_KENTER 1 452 #define CACHEFILES_DEBUG_KLEAVE 2 453 #define CACHEFILES_DEBUG_KDEBUG 4 454 455 #define dbgprintk(FMT, ...) \ 456 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 457 458 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 459 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 460 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 461 462 463 #if defined(__KDEBUG) 464 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 465 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 466 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 467 468 #elif defined(CONFIG_CACHEFILES_DEBUG) 469 #define _enter(FMT, ...) \ 470 do { \ 471 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 472 kenter(FMT, ##__VA_ARGS__); \ 473 } while (0) 474 475 #define _leave(FMT, ...) \ 476 do { \ 477 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 478 kleave(FMT, ##__VA_ARGS__); \ 479 } while (0) 480 481 #define _debug(FMT, ...) \ 482 do { \ 483 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 484 kdebug(FMT, ##__VA_ARGS__); \ 485 } while (0) 486 487 #else 488 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 489 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 490 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 491 #endif 492 493 #if 1 /* defined(__KDEBUGALL) */ 494 495 #define ASSERT(X) \ 496 do { \ 497 if (unlikely(!(X))) { \ 498 pr_err("\n"); \ 499 pr_err("Assertion failed\n"); \ 500 BUG(); \ 501 } \ 502 } while (0) 503 504 #define ASSERTCMP(X, OP, Y) \ 505 do { \ 506 if (unlikely(!((X) OP (Y)))) { \ 507 pr_err("\n"); \ 508 pr_err("Assertion failed\n"); \ 509 pr_err("%lx " #OP " %lx is false\n", \ 510 (unsigned long)(X), (unsigned long)(Y)); \ 511 BUG(); \ 512 } \ 513 } while (0) 514 515 #define ASSERTIF(C, X) \ 516 do { \ 517 if (unlikely((C) && !(X))) { \ 518 pr_err("\n"); \ 519 pr_err("Assertion failed\n"); \ 520 BUG(); \ 521 } \ 522 } while (0) 523 524 #define ASSERTIFCMP(C, X, OP, Y) \ 525 do { \ 526 if (unlikely((C) && !((X) OP (Y)))) { \ 527 pr_err("\n"); \ 528 pr_err("Assertion failed\n"); \ 529 pr_err("%lx " #OP " %lx is false\n", \ 530 (unsigned long)(X), (unsigned long)(Y)); \ 531 BUG(); \ 532 } \ 533 } while (0) 534 535 #else 536 537 #define ASSERT(X) do {} while (0) 538 #define ASSERTCMP(X, OP, Y) do {} while (0) 539 #define ASSERTIF(C, X) do {} while (0) 540 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 541 542 #endif 543