1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* General netfs cache on cache files internal defs 3 * 4 * Copyright (C) 2007 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/timer.h> 17 #include <linux/wait_bit.h> 18 #include <linux/cred.h> 19 #include <linux/workqueue.h> 20 #include <linux/security.h> 21 22 struct cachefiles_cache; 23 struct cachefiles_object; 24 25 extern unsigned cachefiles_debug; 26 #define CACHEFILES_DEBUG_KENTER 1 27 #define CACHEFILES_DEBUG_KLEAVE 2 28 #define CACHEFILES_DEBUG_KDEBUG 4 29 30 #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC) 31 32 /* 33 * node records 34 */ 35 struct cachefiles_object { 36 struct fscache_object fscache; /* fscache handle */ 37 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */ 38 struct dentry *dentry; /* the file/dir representing this object */ 39 struct dentry *backer; /* backing file */ 40 loff_t i_size; /* object size */ 41 unsigned long flags; 42 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */ 43 atomic_t usage; /* object usage count */ 44 uint8_t type; /* object type */ 45 uint8_t new; /* T if object new */ 46 spinlock_t work_lock; 47 struct rb_node active_node; /* link in active tree (dentry is key) */ 48 }; 49 50 extern struct kmem_cache *cachefiles_object_jar; 51 52 /* 53 * Cache files cache definition 54 */ 55 struct cachefiles_cache { 56 struct fscache_cache cache; /* FS-Cache record */ 57 struct vfsmount *mnt; /* mountpoint holding the cache */ 58 struct dentry *graveyard; /* directory into which dead objects go */ 59 struct file *cachefilesd; /* manager daemon handle */ 60 const struct cred *cache_cred; /* security override for accessing cache */ 61 struct mutex daemon_mutex; /* command serialisation mutex */ 62 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ 63 struct rb_root active_nodes; /* active nodes (can't be culled) */ 64 rwlock_t active_lock; /* lock for active_nodes */ 65 atomic_t gravecounter; /* graveyard uniquifier */ 66 atomic_t f_released; /* number of objects released lately */ 67 atomic_long_t b_released; /* number of blocks released lately */ 68 unsigned frun_percent; /* when to stop culling (% files) */ 69 unsigned fcull_percent; /* when to start culling (% files) */ 70 unsigned fstop_percent; /* when to stop allocating (% files) */ 71 unsigned brun_percent; /* when to stop culling (% blocks) */ 72 unsigned bcull_percent; /* when to start culling (% blocks) */ 73 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 74 unsigned bsize; /* cache's block size */ 75 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 76 uint64_t frun; /* when to stop culling */ 77 uint64_t fcull; /* when to start culling */ 78 uint64_t fstop; /* when to stop allocating */ 79 sector_t brun; /* when to stop culling */ 80 sector_t bcull; /* when to start culling */ 81 sector_t bstop; /* when to stop allocating */ 82 unsigned long flags; 83 #define CACHEFILES_READY 0 /* T if cache prepared */ 84 #define CACHEFILES_DEAD 1 /* T if cache dead */ 85 #define CACHEFILES_CULLING 2 /* T if cull engaged */ 86 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 87 char *rootdirname; /* name of cache root directory */ 88 char *secctx; /* LSM security context */ 89 char *tag; /* cache binding tag */ 90 }; 91 92 /* 93 * backing file read tracking 94 */ 95 struct cachefiles_one_read { 96 wait_queue_entry_t monitor; /* link into monitored waitqueue */ 97 struct page *back_page; /* backing file page we're waiting for */ 98 struct page *netfs_page; /* netfs page we're going to fill */ 99 struct fscache_retrieval *op; /* retrieval op covering this */ 100 struct list_head op_link; /* link in op's todo list */ 101 }; 102 103 /* 104 * backing file write tracking 105 */ 106 struct cachefiles_one_write { 107 struct page *netfs_page; /* netfs page to copy */ 108 struct cachefiles_object *object; 109 struct list_head obj_link; /* link in object's lists */ 110 fscache_rw_complete_t end_io_func; 111 void *context; 112 }; 113 114 /* 115 * auxiliary data xattr buffer 116 */ 117 struct cachefiles_xattr { 118 uint16_t len; 119 uint8_t type; 120 uint8_t data[]; 121 }; 122 123 #include <trace/events/cachefiles.h> 124 125 /* 126 * note change of state for daemon 127 */ 128 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 129 { 130 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 131 wake_up_all(&cache->daemon_pollwq); 132 } 133 134 /* 135 * bind.c 136 */ 137 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); 138 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); 139 140 /* 141 * daemon.c 142 */ 143 extern const struct file_operations cachefiles_daemon_fops; 144 145 extern int cachefiles_has_space(struct cachefiles_cache *cache, 146 unsigned fnr, unsigned bnr); 147 148 /* 149 * interface.c 150 */ 151 extern const struct fscache_cache_ops cachefiles_cache_ops; 152 153 /* 154 * key.c 155 */ 156 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); 157 158 /* 159 * namei.c 160 */ 161 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, 162 struct cachefiles_object *object, 163 blkcnt_t i_blocks); 164 extern int cachefiles_delete_object(struct cachefiles_cache *cache, 165 struct cachefiles_object *object); 166 extern int cachefiles_walk_to_object(struct cachefiles_object *parent, 167 struct cachefiles_object *object, 168 const char *key, 169 struct cachefiles_xattr *auxdata); 170 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 171 struct dentry *dir, 172 const char *name); 173 174 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 175 char *filename); 176 177 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 178 struct dentry *dir, char *filename); 179 180 /* 181 * proc.c 182 */ 183 #ifdef CONFIG_CACHEFILES_HISTOGRAM 184 extern atomic_t cachefiles_lookup_histogram[HZ]; 185 extern atomic_t cachefiles_mkdir_histogram[HZ]; 186 extern atomic_t cachefiles_create_histogram[HZ]; 187 188 extern int __init cachefiles_proc_init(void); 189 extern void cachefiles_proc_cleanup(void); 190 static inline 191 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif) 192 { 193 unsigned long jif = jiffies - start_jif; 194 if (jif >= HZ) 195 jif = HZ - 1; 196 atomic_inc(&histogram[jif]); 197 } 198 199 #else 200 #define cachefiles_proc_init() (0) 201 #define cachefiles_proc_cleanup() do {} while (0) 202 #define cachefiles_hist(hist, start_jif) do {} while (0) 203 #endif 204 205 /* 206 * rdwr.c 207 */ 208 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, 209 struct page *, gfp_t); 210 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, 211 struct list_head *, unsigned *, 212 gfp_t); 213 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, 214 gfp_t); 215 extern int cachefiles_allocate_pages(struct fscache_retrieval *, 216 struct list_head *, unsigned *, gfp_t); 217 extern int cachefiles_write_page(struct fscache_storage *, struct page *); 218 extern void cachefiles_uncache_page(struct fscache_object *, struct page *); 219 220 /* 221 * security.c 222 */ 223 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 224 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 225 struct dentry *root, 226 const struct cred **_saved_cred); 227 228 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 229 const struct cred **_saved_cred) 230 { 231 *_saved_cred = override_creds(cache->cache_cred); 232 } 233 234 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 235 const struct cred *saved_cred) 236 { 237 revert_creds(saved_cred); 238 } 239 240 /* 241 * xattr.c 242 */ 243 extern int cachefiles_check_object_type(struct cachefiles_object *object); 244 extern int cachefiles_set_object_xattr(struct cachefiles_object *object, 245 struct cachefiles_xattr *auxdata); 246 extern int cachefiles_update_object_xattr(struct cachefiles_object *object, 247 struct cachefiles_xattr *auxdata); 248 extern int cachefiles_check_auxdata(struct cachefiles_object *object); 249 extern int cachefiles_check_object_xattr(struct cachefiles_object *object, 250 struct cachefiles_xattr *auxdata); 251 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 252 struct dentry *dentry); 253 254 255 /* 256 * error handling 257 */ 258 259 #define cachefiles_io_error(___cache, FMT, ...) \ 260 do { \ 261 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 262 fscache_io_error(&(___cache)->cache); \ 263 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 264 } while (0) 265 266 #define cachefiles_io_error_obj(object, FMT, ...) \ 267 do { \ 268 struct cachefiles_cache *___cache; \ 269 \ 270 ___cache = container_of((object)->fscache.cache, \ 271 struct cachefiles_cache, cache); \ 272 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ 273 } while (0) 274 275 276 /* 277 * debug tracing 278 */ 279 #define dbgprintk(FMT, ...) \ 280 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 281 282 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 283 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 284 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 285 286 287 #if defined(__KDEBUG) 288 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 289 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 290 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 291 292 #elif defined(CONFIG_CACHEFILES_DEBUG) 293 #define _enter(FMT, ...) \ 294 do { \ 295 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 296 kenter(FMT, ##__VA_ARGS__); \ 297 } while (0) 298 299 #define _leave(FMT, ...) \ 300 do { \ 301 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 302 kleave(FMT, ##__VA_ARGS__); \ 303 } while (0) 304 305 #define _debug(FMT, ...) \ 306 do { \ 307 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 308 kdebug(FMT, ##__VA_ARGS__); \ 309 } while (0) 310 311 #else 312 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 313 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 314 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 315 #endif 316 317 #if 1 /* defined(__KDEBUGALL) */ 318 319 #define ASSERT(X) \ 320 do { \ 321 if (unlikely(!(X))) { \ 322 pr_err("\n"); \ 323 pr_err("Assertion failed\n"); \ 324 BUG(); \ 325 } \ 326 } while (0) 327 328 #define ASSERTCMP(X, OP, Y) \ 329 do { \ 330 if (unlikely(!((X) OP (Y)))) { \ 331 pr_err("\n"); \ 332 pr_err("Assertion failed\n"); \ 333 pr_err("%lx " #OP " %lx is false\n", \ 334 (unsigned long)(X), (unsigned long)(Y)); \ 335 BUG(); \ 336 } \ 337 } while (0) 338 339 #define ASSERTIF(C, X) \ 340 do { \ 341 if (unlikely((C) && !(X))) { \ 342 pr_err("\n"); \ 343 pr_err("Assertion failed\n"); \ 344 BUG(); \ 345 } \ 346 } while (0) 347 348 #define ASSERTIFCMP(C, X, OP, Y) \ 349 do { \ 350 if (unlikely((C) && !((X) OP (Y)))) { \ 351 pr_err("\n"); \ 352 pr_err("Assertion failed\n"); \ 353 pr_err("%lx " #OP " %lx is false\n", \ 354 (unsigned long)(X), (unsigned long)(Y)); \ 355 BUG(); \ 356 } \ 357 } while (0) 358 359 #else 360 361 #define ASSERT(X) do {} while (0) 362 #define ASSERTCMP(X, OP, Y) do {} while (0) 363 #define ASSERTIF(C, X) do {} while (0) 364 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 365 366 #endif 367