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 struct xarray ondemand_ids; /* xarray for ondemand_id allocation */ 115 u32 ondemand_id_next; 116 }; 117 118 static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache) 119 { 120 return IS_ENABLED(CONFIG_CACHEFILES_ONDEMAND) && 121 test_bit(CACHEFILES_ONDEMAND_MODE, &cache->flags); 122 } 123 124 struct cachefiles_req { 125 struct cachefiles_object *object; 126 struct completion done; 127 int error; 128 struct cachefiles_msg msg; 129 }; 130 131 #define CACHEFILES_REQ_NEW XA_MARK_1 132 133 #include <trace/events/cachefiles.h> 134 135 static inline 136 struct file *cachefiles_cres_file(struct netfs_cache_resources *cres) 137 { 138 return cres->cache_priv2; 139 } 140 141 static inline 142 struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres) 143 { 144 return fscache_cres_cookie(cres)->cache_priv; 145 } 146 147 /* 148 * note change of state for daemon 149 */ 150 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 151 { 152 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 153 wake_up_all(&cache->daemon_pollwq); 154 } 155 156 /* 157 * cache.c 158 */ 159 extern int cachefiles_add_cache(struct cachefiles_cache *cache); 160 extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache); 161 162 enum cachefiles_has_space_for { 163 cachefiles_has_space_check, 164 cachefiles_has_space_for_write, 165 cachefiles_has_space_for_create, 166 }; 167 extern int cachefiles_has_space(struct cachefiles_cache *cache, 168 unsigned fnr, unsigned bnr, 169 enum cachefiles_has_space_for reason); 170 171 /* 172 * daemon.c 173 */ 174 extern const struct file_operations cachefiles_daemon_fops; 175 extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache); 176 extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache); 177 178 /* 179 * error_inject.c 180 */ 181 #ifdef CONFIG_CACHEFILES_ERROR_INJECTION 182 extern unsigned int cachefiles_error_injection_state; 183 extern int cachefiles_register_error_injection(void); 184 extern void cachefiles_unregister_error_injection(void); 185 186 #else 187 #define cachefiles_error_injection_state 0 188 189 static inline int cachefiles_register_error_injection(void) 190 { 191 return 0; 192 } 193 194 static inline void cachefiles_unregister_error_injection(void) 195 { 196 } 197 #endif 198 199 200 static inline int cachefiles_inject_read_error(void) 201 { 202 return cachefiles_error_injection_state & 2 ? -EIO : 0; 203 } 204 205 static inline int cachefiles_inject_write_error(void) 206 { 207 return cachefiles_error_injection_state & 2 ? -EIO : 208 cachefiles_error_injection_state & 1 ? -ENOSPC : 209 0; 210 } 211 212 static inline int cachefiles_inject_remove_error(void) 213 { 214 return cachefiles_error_injection_state & 2 ? -EIO : 0; 215 } 216 217 /* 218 * interface.c 219 */ 220 extern const struct fscache_cache_ops cachefiles_cache_ops; 221 extern void cachefiles_see_object(struct cachefiles_object *object, 222 enum cachefiles_obj_ref_trace why); 223 extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object, 224 enum cachefiles_obj_ref_trace why); 225 extern void cachefiles_put_object(struct cachefiles_object *object, 226 enum cachefiles_obj_ref_trace why); 227 228 /* 229 * io.c 230 */ 231 extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres, 232 enum fscache_want_state want_state); 233 extern int __cachefiles_prepare_write(struct cachefiles_object *object, 234 struct file *file, 235 loff_t *_start, size_t *_len, 236 bool no_space_allocated_yet); 237 extern int __cachefiles_write(struct cachefiles_object *object, 238 struct file *file, 239 loff_t start_pos, 240 struct iov_iter *iter, 241 netfs_io_terminated_t term_func, 242 void *term_func_priv); 243 244 /* 245 * key.c 246 */ 247 extern bool cachefiles_cook_key(struct cachefiles_object *object); 248 249 /* 250 * main.c 251 */ 252 extern struct kmem_cache *cachefiles_object_jar; 253 254 /* 255 * namei.c 256 */ 257 extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 258 struct file *file); 259 extern int cachefiles_bury_object(struct cachefiles_cache *cache, 260 struct cachefiles_object *object, 261 struct dentry *dir, 262 struct dentry *rep, 263 enum fscache_why_object_killed why); 264 extern int cachefiles_delete_object(struct cachefiles_object *object, 265 enum fscache_why_object_killed why); 266 extern bool cachefiles_look_up_object(struct cachefiles_object *object); 267 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 268 struct dentry *dir, 269 const char *name, 270 bool *_is_new); 271 extern void cachefiles_put_directory(struct dentry *dir); 272 273 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 274 char *filename); 275 276 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 277 struct dentry *dir, char *filename); 278 extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object); 279 extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache, 280 struct cachefiles_object *object); 281 282 /* 283 * ondemand.c 284 */ 285 #ifdef CONFIG_CACHEFILES_ONDEMAND 286 extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, 287 char __user *_buffer, size_t buflen); 288 289 extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache, 290 char *args); 291 292 extern int cachefiles_ondemand_init_object(struct cachefiles_object *object); 293 294 #else 295 static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, 296 char __user *_buffer, size_t buflen) 297 { 298 return -EOPNOTSUPP; 299 } 300 301 static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object) 302 { 303 return 0; 304 } 305 #endif 306 307 /* 308 * security.c 309 */ 310 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 311 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 312 struct dentry *root, 313 const struct cred **_saved_cred); 314 315 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 316 const struct cred **_saved_cred) 317 { 318 *_saved_cred = override_creds(cache->cache_cred); 319 } 320 321 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 322 const struct cred *saved_cred) 323 { 324 revert_creds(saved_cred); 325 } 326 327 /* 328 * volume.c 329 */ 330 void cachefiles_acquire_volume(struct fscache_volume *volume); 331 void cachefiles_free_volume(struct fscache_volume *volume); 332 void cachefiles_withdraw_volume(struct cachefiles_volume *volume); 333 334 /* 335 * xattr.c 336 */ 337 extern int cachefiles_set_object_xattr(struct cachefiles_object *object); 338 extern int cachefiles_check_auxdata(struct cachefiles_object *object, 339 struct file *file); 340 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 341 struct cachefiles_object *object, 342 struct dentry *dentry); 343 extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie); 344 extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume); 345 extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume); 346 347 /* 348 * Error handling 349 */ 350 #define cachefiles_io_error(___cache, FMT, ...) \ 351 do { \ 352 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 353 fscache_io_error((___cache)->cache); \ 354 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 355 } while (0) 356 357 #define cachefiles_io_error_obj(object, FMT, ...) \ 358 do { \ 359 struct cachefiles_cache *___cache; \ 360 \ 361 ___cache = (object)->volume->cache; \ 362 cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \ 363 (object)->debug_id); \ 364 } while (0) 365 366 367 /* 368 * Debug tracing 369 */ 370 extern unsigned cachefiles_debug; 371 #define CACHEFILES_DEBUG_KENTER 1 372 #define CACHEFILES_DEBUG_KLEAVE 2 373 #define CACHEFILES_DEBUG_KDEBUG 4 374 375 #define dbgprintk(FMT, ...) \ 376 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 377 378 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 379 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 380 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 381 382 383 #if defined(__KDEBUG) 384 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 385 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 386 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 387 388 #elif defined(CONFIG_CACHEFILES_DEBUG) 389 #define _enter(FMT, ...) \ 390 do { \ 391 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 392 kenter(FMT, ##__VA_ARGS__); \ 393 } while (0) 394 395 #define _leave(FMT, ...) \ 396 do { \ 397 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 398 kleave(FMT, ##__VA_ARGS__); \ 399 } while (0) 400 401 #define _debug(FMT, ...) \ 402 do { \ 403 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 404 kdebug(FMT, ##__VA_ARGS__); \ 405 } while (0) 406 407 #else 408 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 409 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 410 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 411 #endif 412 413 #if 1 /* defined(__KDEBUGALL) */ 414 415 #define ASSERT(X) \ 416 do { \ 417 if (unlikely(!(X))) { \ 418 pr_err("\n"); \ 419 pr_err("Assertion failed\n"); \ 420 BUG(); \ 421 } \ 422 } while (0) 423 424 #define ASSERTCMP(X, OP, Y) \ 425 do { \ 426 if (unlikely(!((X) OP (Y)))) { \ 427 pr_err("\n"); \ 428 pr_err("Assertion failed\n"); \ 429 pr_err("%lx " #OP " %lx is false\n", \ 430 (unsigned long)(X), (unsigned long)(Y)); \ 431 BUG(); \ 432 } \ 433 } while (0) 434 435 #define ASSERTIF(C, X) \ 436 do { \ 437 if (unlikely((C) && !(X))) { \ 438 pr_err("\n"); \ 439 pr_err("Assertion failed\n"); \ 440 BUG(); \ 441 } \ 442 } while (0) 443 444 #define ASSERTIFCMP(C, X, OP, Y) \ 445 do { \ 446 if (unlikely((C) && !((X) OP (Y)))) { \ 447 pr_err("\n"); \ 448 pr_err("Assertion failed\n"); \ 449 pr_err("%lx " #OP " %lx is false\n", \ 450 (unsigned long)(X), (unsigned long)(Y)); \ 451 BUG(); \ 452 } \ 453 } while (0) 454 455 #else 456 457 #define ASSERT(X) do {} while (0) 458 #define ASSERTCMP(X, OP, Y) do {} while (0) 459 #define ASSERTIF(C, X) do {} while (0) 460 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 461 462 #endif 463