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 19 #define CACHEFILES_DIO_BLOCK_SIZE 4096 20 21 struct cachefiles_cache; 22 struct cachefiles_object; 23 24 enum cachefiles_content { 25 /* These values are saved on disk */ 26 CACHEFILES_CONTENT_NO_DATA = 0, /* No content stored */ 27 CACHEFILES_CONTENT_SINGLE = 1, /* Content is monolithic, all is present */ 28 CACHEFILES_CONTENT_ALL = 2, /* Content is all present, no map */ 29 CACHEFILES_CONTENT_BACKFS_MAP = 3, /* Content is piecemeal, mapped through backing fs */ 30 CACHEFILES_CONTENT_DIRTY = 4, /* Content is dirty (only seen on disk) */ 31 nr__cachefiles_content 32 }; 33 34 /* 35 * Cached volume representation. 36 */ 37 struct cachefiles_volume { 38 struct cachefiles_cache *cache; 39 struct list_head cache_link; /* Link in cache->volumes */ 40 struct fscache_volume *vcookie; /* The netfs's representation */ 41 struct dentry *dentry; /* The volume dentry */ 42 struct dentry *fanout[256]; /* Fanout subdirs */ 43 }; 44 45 /* 46 * Backing file state. 47 */ 48 struct cachefiles_object { 49 struct fscache_cookie *cookie; /* Netfs data storage object cookie */ 50 struct cachefiles_volume *volume; /* Cache volume that holds this object */ 51 struct list_head cache_link; /* Link in cache->*_list */ 52 struct file *file; /* The file representing this object */ 53 char *d_name; /* Backing file name */ 54 int debug_id; 55 spinlock_t lock; 56 refcount_t ref; 57 u8 d_name_len; /* Length of filename */ 58 enum cachefiles_content content_info:8; /* Info about content presence */ 59 unsigned long flags; 60 #define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */ 61 }; 62 63 /* 64 * Cache files cache definition 65 */ 66 struct cachefiles_cache { 67 struct fscache_cache *cache; /* Cache cookie */ 68 struct vfsmount *mnt; /* mountpoint holding the cache */ 69 struct dentry *store; /* Directory into which live objects go */ 70 struct dentry *graveyard; /* directory into which dead objects go */ 71 struct file *cachefilesd; /* manager daemon handle */ 72 struct list_head volumes; /* List of volume objects */ 73 struct list_head object_list; /* List of active objects */ 74 spinlock_t object_list_lock; /* Lock for volumes and object_list */ 75 const struct cred *cache_cred; /* security override for accessing cache */ 76 struct mutex daemon_mutex; /* command serialisation mutex */ 77 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ 78 atomic_t gravecounter; /* graveyard uniquifier */ 79 atomic_t f_released; /* number of objects released lately */ 80 atomic_long_t b_released; /* number of blocks released lately */ 81 atomic_long_t b_writing; /* Number of blocks being written */ 82 unsigned frun_percent; /* when to stop culling (% files) */ 83 unsigned fcull_percent; /* when to start culling (% files) */ 84 unsigned fstop_percent; /* when to stop allocating (% files) */ 85 unsigned brun_percent; /* when to stop culling (% blocks) */ 86 unsigned bcull_percent; /* when to start culling (% blocks) */ 87 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 88 unsigned bsize; /* cache's block size */ 89 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 90 uint64_t frun; /* when to stop culling */ 91 uint64_t fcull; /* when to start culling */ 92 uint64_t fstop; /* when to stop allocating */ 93 sector_t brun; /* when to stop culling */ 94 sector_t bcull; /* when to start culling */ 95 sector_t bstop; /* when to stop allocating */ 96 unsigned long flags; 97 #define CACHEFILES_READY 0 /* T if cache prepared */ 98 #define CACHEFILES_DEAD 1 /* T if cache dead */ 99 #define CACHEFILES_CULLING 2 /* T if cull engaged */ 100 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 101 char *rootdirname; /* name of cache root directory */ 102 char *secctx; /* LSM security context */ 103 char *tag; /* cache binding tag */ 104 }; 105 106 #include <trace/events/cachefiles.h> 107 108 static inline 109 struct file *cachefiles_cres_file(struct netfs_cache_resources *cres) 110 { 111 return cres->cache_priv2; 112 } 113 114 static inline 115 struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres) 116 { 117 return fscache_cres_cookie(cres)->cache_priv; 118 } 119 120 /* 121 * note change of state for daemon 122 */ 123 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 124 { 125 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 126 wake_up_all(&cache->daemon_pollwq); 127 } 128 129 /* 130 * cache.c 131 */ 132 extern int cachefiles_add_cache(struct cachefiles_cache *cache); 133 extern void cachefiles_withdraw_cache(struct cachefiles_cache *cache); 134 135 enum cachefiles_has_space_for { 136 cachefiles_has_space_check, 137 cachefiles_has_space_for_write, 138 cachefiles_has_space_for_create, 139 }; 140 extern int cachefiles_has_space(struct cachefiles_cache *cache, 141 unsigned fnr, unsigned bnr, 142 enum cachefiles_has_space_for reason); 143 144 /* 145 * daemon.c 146 */ 147 extern const struct file_operations cachefiles_daemon_fops; 148 149 /* 150 * error_inject.c 151 */ 152 #ifdef CONFIG_CACHEFILES_ERROR_INJECTION 153 extern unsigned int cachefiles_error_injection_state; 154 extern int cachefiles_register_error_injection(void); 155 extern void cachefiles_unregister_error_injection(void); 156 157 #else 158 #define cachefiles_error_injection_state 0 159 160 static inline int cachefiles_register_error_injection(void) 161 { 162 return 0; 163 } 164 165 static inline void cachefiles_unregister_error_injection(void) 166 { 167 } 168 #endif 169 170 171 static inline int cachefiles_inject_read_error(void) 172 { 173 return cachefiles_error_injection_state & 2 ? -EIO : 0; 174 } 175 176 static inline int cachefiles_inject_write_error(void) 177 { 178 return cachefiles_error_injection_state & 2 ? -EIO : 179 cachefiles_error_injection_state & 1 ? -ENOSPC : 180 0; 181 } 182 183 static inline int cachefiles_inject_remove_error(void) 184 { 185 return cachefiles_error_injection_state & 2 ? -EIO : 0; 186 } 187 188 /* 189 * interface.c 190 */ 191 extern const struct fscache_cache_ops cachefiles_cache_ops; 192 extern void cachefiles_see_object(struct cachefiles_object *object, 193 enum cachefiles_obj_ref_trace why); 194 extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object, 195 enum cachefiles_obj_ref_trace why); 196 extern void cachefiles_put_object(struct cachefiles_object *object, 197 enum cachefiles_obj_ref_trace why); 198 199 /* 200 * io.c 201 */ 202 extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres, 203 enum fscache_want_state want_state); 204 205 /* 206 * key.c 207 */ 208 extern bool cachefiles_cook_key(struct cachefiles_object *object); 209 210 /* 211 * main.c 212 */ 213 extern struct kmem_cache *cachefiles_object_jar; 214 215 /* 216 * namei.c 217 */ 218 extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object, 219 struct file *file); 220 extern int cachefiles_bury_object(struct cachefiles_cache *cache, 221 struct cachefiles_object *object, 222 struct dentry *dir, 223 struct dentry *rep, 224 enum fscache_why_object_killed why); 225 extern int cachefiles_delete_object(struct cachefiles_object *object, 226 enum fscache_why_object_killed why); 227 extern bool cachefiles_look_up_object(struct cachefiles_object *object); 228 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 229 struct dentry *dir, 230 const char *name, 231 bool *_is_new); 232 extern void cachefiles_put_directory(struct dentry *dir); 233 234 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 235 char *filename); 236 237 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 238 struct dentry *dir, char *filename); 239 extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object); 240 extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache, 241 struct cachefiles_object *object); 242 243 /* 244 * security.c 245 */ 246 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 247 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 248 struct dentry *root, 249 const struct cred **_saved_cred); 250 251 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 252 const struct cred **_saved_cred) 253 { 254 *_saved_cred = override_creds(cache->cache_cred); 255 } 256 257 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 258 const struct cred *saved_cred) 259 { 260 revert_creds(saved_cred); 261 } 262 263 /* 264 * volume.c 265 */ 266 void cachefiles_acquire_volume(struct fscache_volume *volume); 267 void cachefiles_free_volume(struct fscache_volume *volume); 268 void cachefiles_withdraw_volume(struct cachefiles_volume *volume); 269 270 /* 271 * xattr.c 272 */ 273 extern int cachefiles_set_object_xattr(struct cachefiles_object *object); 274 extern int cachefiles_check_auxdata(struct cachefiles_object *object, 275 struct file *file); 276 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 277 struct cachefiles_object *object, 278 struct dentry *dentry); 279 extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie); 280 extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume); 281 extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume); 282 283 /* 284 * Error handling 285 */ 286 #define cachefiles_io_error(___cache, FMT, ...) \ 287 do { \ 288 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 289 fscache_io_error((___cache)->cache); \ 290 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 291 } while (0) 292 293 #define cachefiles_io_error_obj(object, FMT, ...) \ 294 do { \ 295 struct cachefiles_cache *___cache; \ 296 \ 297 ___cache = (object)->volume->cache; \ 298 cachefiles_io_error(___cache, FMT " [o=%08x]", ##__VA_ARGS__, \ 299 (object)->debug_id); \ 300 } while (0) 301 302 303 /* 304 * Debug tracing 305 */ 306 extern unsigned cachefiles_debug; 307 #define CACHEFILES_DEBUG_KENTER 1 308 #define CACHEFILES_DEBUG_KLEAVE 2 309 #define CACHEFILES_DEBUG_KDEBUG 4 310 311 #define dbgprintk(FMT, ...) \ 312 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 313 314 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 315 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 316 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 317 318 319 #if defined(__KDEBUG) 320 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 321 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 322 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 323 324 #elif defined(CONFIG_CACHEFILES_DEBUG) 325 #define _enter(FMT, ...) \ 326 do { \ 327 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 328 kenter(FMT, ##__VA_ARGS__); \ 329 } while (0) 330 331 #define _leave(FMT, ...) \ 332 do { \ 333 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 334 kleave(FMT, ##__VA_ARGS__); \ 335 } while (0) 336 337 #define _debug(FMT, ...) \ 338 do { \ 339 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 340 kdebug(FMT, ##__VA_ARGS__); \ 341 } while (0) 342 343 #else 344 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 345 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 346 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 347 #endif 348 349 #if 1 /* defined(__KDEBUGALL) */ 350 351 #define ASSERT(X) \ 352 do { \ 353 if (unlikely(!(X))) { \ 354 pr_err("\n"); \ 355 pr_err("Assertion failed\n"); \ 356 BUG(); \ 357 } \ 358 } while (0) 359 360 #define ASSERTCMP(X, OP, Y) \ 361 do { \ 362 if (unlikely(!((X) OP (Y)))) { \ 363 pr_err("\n"); \ 364 pr_err("Assertion failed\n"); \ 365 pr_err("%lx " #OP " %lx is false\n", \ 366 (unsigned long)(X), (unsigned long)(Y)); \ 367 BUG(); \ 368 } \ 369 } while (0) 370 371 #define ASSERTIF(C, X) \ 372 do { \ 373 if (unlikely((C) && !(X))) { \ 374 pr_err("\n"); \ 375 pr_err("Assertion failed\n"); \ 376 BUG(); \ 377 } \ 378 } while (0) 379 380 #define ASSERTIFCMP(C, X, OP, Y) \ 381 do { \ 382 if (unlikely((C) && !((X) OP (Y)))) { \ 383 pr_err("\n"); \ 384 pr_err("Assertion failed\n"); \ 385 pr_err("%lx " #OP " %lx is false\n", \ 386 (unsigned long)(X), (unsigned long)(Y)); \ 387 BUG(); \ 388 } \ 389 } while (0) 390 391 #else 392 393 #define ASSERT(X) do {} while (0) 394 #define ASSERTCMP(X, OP, Y) do {} while (0) 395 #define ASSERTIF(C, X) do {} while (0) 396 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 397 398 #endif 399