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 23struct cachefiles_cache; 24struct cachefiles_object; 25 26enum 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 */ 39struct 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 47enum 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 53struct 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 */ 63struct 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 */ 86struct 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 132static 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 138struct 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 149static inline 150struct file *cachefiles_cres_file(struct netfs_cache_resources *cres) 151{ 152 return cres->cache_priv2; 153} 154 155static inline 156struct 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 */ 164static 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 */ 173extern int cachefiles_add_cache(struct cachefiles_cache *cache); 174extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache); 175 176enum cachefiles_has_space_for { 177 cachefiles_has_space_check, 178 cachefiles_has_space_for_write, 179 cachefiles_has_space_for_create, 180}; 181extern 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 */ 188extern const struct file_operations cachefiles_daemon_fops; 189extern void cachefiles_get_unbind_pincount(struct cachefiles_cache *cache); 190extern void cachefiles_put_unbind_pincount(struct cachefiles_cache *cache); 191 192/* 193 * error_inject.c 194 */ 195#ifdef CONFIG_CACHEFILES_ERROR_INJECTION 196extern unsigned int cachefiles_error_injection_state; 197extern int cachefiles_register_error_injection(void); 198extern void cachefiles_unregister_error_injection(void); 199 200#else 201#define cachefiles_error_injection_state 0 202 203static inline int cachefiles_register_error_injection(void) 204{ 205 return 0; 206} 207 208static inline void cachefiles_unregister_error_injection(void) 209{ 210} 211#endif 212 213 214static inline int cachefiles_inject_read_error(void) 215{ 216 return cachefiles_error_injection_state & 2 ? -EIO : 0; 217} 218 219static 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 226static inline int cachefiles_inject_remove_error(void) 227{ 228 return cachefiles_error_injection_state & 2 ? -EIO : 0; 229} 230 231/* 232 * interface.c 233 */ 234extern const struct fscache_cache_ops cachefiles_cache_ops; 235extern void cachefiles_see_object(struct cachefiles_object *object, 236 enum cachefiles_obj_ref_trace why); 237extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object, 238 enum cachefiles_obj_ref_trace why); 239extern void cachefiles_put_object(struct cachefiles_object *object, 240 enum cachefiles_obj_ref_trace why); 241 242/* 243 * io.c 244 */ 245extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres, 246 enum fscache_want_state want_state); 247extern 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); 251extern 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 */ 261extern bool cachefiles_cook_key(struct cachefiles_object *object); 262 263/* 264 * main.c 265 */ 266extern struct kmem_cache *cachefiles_object_jar; 267 268/* 269 * namei.c 270 */ 271extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 272 struct file *file); 273extern 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); 278extern int cachefiles_delete_object(struct cachefiles_object *object, 279 enum fscache_why_object_killed why); 280extern bool cachefiles_look_up_object(struct cachefiles_object *object); 281extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 282 struct dentry *dir, 283 const char *name, 284 bool *_is_new); 285extern void cachefiles_put_directory(struct dentry *dir); 286 287extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 288 char *filename); 289 290extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 291 struct dentry *dir, char *filename); 292extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object); 293extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache, 294 struct cachefiles_object *object); 295 296/* 297 * ondemand.c 298 */ 299#ifdef CONFIG_CACHEFILES_ONDEMAND 300extern ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, 301 char __user *_buffer, size_t buflen); 302 303extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache, 304 char *args); 305 306extern int cachefiles_ondemand_restore(struct cachefiles_cache *cache, 307 char *args); 308 309extern int cachefiles_ondemand_init_object(struct cachefiles_object *object); 310extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object); 311 312extern int cachefiles_ondemand_read(struct cachefiles_object *object, 313 loff_t pos, size_t len); 314 315extern int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj, 316 struct cachefiles_volume *volume); 317extern void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj); 318 319#define CACHEFILES_OBJECT_STATE_FUNCS(_state, _STATE) \ 320static inline bool \ 321cachefiles_ondemand_object_is_##_state(const struct cachefiles_object *object) \ 322{ \ 323 return object->ondemand->state == CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \ 324} \ 325 \ 326static inline void \ 327cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \ 328{ \ 329 object->ondemand->state = CACHEFILES_ONDEMAND_OBJSTATE_##_STATE; \ 330} 331 332CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN); 333CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE); 334CACHEFILES_OBJECT_STATE_FUNCS(reopening, REOPENING); 335 336static 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 343static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, 344 char __user *_buffer, size_t buflen) 345{ 346 return -EOPNOTSUPP; 347} 348 349static inline int cachefiles_ondemand_init_object(struct cachefiles_object *object) 350{ 351 return 0; 352} 353 354static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object) 355{ 356} 357 358static inline int cachefiles_ondemand_read(struct cachefiles_object *object, 359 loff_t pos, size_t len) 360{ 361 return -EOPNOTSUPP; 362} 363 364static inline int cachefiles_ondemand_init_obj_info(struct cachefiles_object *obj, 365 struct cachefiles_volume *volume) 366{ 367 return 0; 368} 369static inline void cachefiles_ondemand_deinit_obj_info(struct cachefiles_object *obj) 370{ 371} 372 373static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req) 374{ 375 return false; 376} 377#endif 378 379/* 380 * security.c 381 */ 382extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 383extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 384 struct dentry *root, 385 const struct cred **_saved_cred); 386 387static 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 393static 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 */ 402void cachefiles_acquire_volume(struct fscache_volume *volume); 403void cachefiles_free_volume(struct fscache_volume *volume); 404void cachefiles_withdraw_volume(struct cachefiles_volume *volume); 405 406/* 407 * xattr.c 408 */ 409extern int cachefiles_set_object_xattr(struct cachefiles_object *object); 410extern int cachefiles_check_auxdata(struct cachefiles_object *object, 411 struct file *file); 412extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 413 struct cachefiles_object *object, 414 struct dentry *dentry); 415extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie); 416extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume); 417extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume); 418 419/* 420 * Error handling 421 */ 422#define cachefiles_io_error(___cache, FMT, ...) \ 423do { \ 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, ...) \ 430do { \ 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 */ 442extern 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, ...) \ 462do { \ 463 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 464 kenter(FMT, ##__VA_ARGS__); \ 465} while (0) 466 467#define _leave(FMT, ...) \ 468do { \ 469 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 470 kleave(FMT, ##__VA_ARGS__); \ 471} while (0) 472 473#define _debug(FMT, ...) \ 474do { \ 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) \ 488do { \ 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) \ 497do { \ 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) \ 508do { \ 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) \ 517do { \ 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