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, &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