1 /* General netfs cache on cache files internal defs 2 * 3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public Licence 8 * as published by the Free Software Foundation; either version 9 * 2 of the Licence, or (at your option) any later version. 10 */ 11 12 #include <linux/fscache-cache.h> 13 #include <linux/timer.h> 14 #include <linux/wait.h> 15 #include <linux/workqueue.h> 16 #include <linux/security.h> 17 18 struct cachefiles_cache; 19 struct cachefiles_object; 20 21 extern unsigned cachefiles_debug; 22 #define CACHEFILES_DEBUG_KENTER 1 23 #define CACHEFILES_DEBUG_KLEAVE 2 24 #define CACHEFILES_DEBUG_KDEBUG 4 25 26 /* 27 * node records 28 */ 29 struct cachefiles_object { 30 struct fscache_object fscache; /* fscache handle */ 31 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */ 32 struct dentry *dentry; /* the file/dir representing this object */ 33 struct dentry *backer; /* backing file */ 34 loff_t i_size; /* object size */ 35 unsigned long flags; 36 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */ 37 atomic_t usage; /* object usage count */ 38 uint8_t type; /* object type */ 39 uint8_t new; /* T if object new */ 40 spinlock_t work_lock; 41 struct rb_node active_node; /* link in active tree (dentry is key) */ 42 }; 43 44 extern struct kmem_cache *cachefiles_object_jar; 45 46 /* 47 * Cache files cache definition 48 */ 49 struct cachefiles_cache { 50 struct fscache_cache cache; /* FS-Cache record */ 51 struct vfsmount *mnt; /* mountpoint holding the cache */ 52 struct dentry *graveyard; /* directory into which dead objects go */ 53 struct file *cachefilesd; /* manager daemon handle */ 54 const struct cred *cache_cred; /* security override for accessing cache */ 55 struct mutex daemon_mutex; /* command serialisation mutex */ 56 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ 57 struct rb_root active_nodes; /* active nodes (can't be culled) */ 58 rwlock_t active_lock; /* lock for active_nodes */ 59 atomic_t gravecounter; /* graveyard uniquifier */ 60 unsigned frun_percent; /* when to stop culling (% files) */ 61 unsigned fcull_percent; /* when to start culling (% files) */ 62 unsigned fstop_percent; /* when to stop allocating (% files) */ 63 unsigned brun_percent; /* when to stop culling (% blocks) */ 64 unsigned bcull_percent; /* when to start culling (% blocks) */ 65 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 66 unsigned bsize; /* cache's block size */ 67 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 68 uint64_t frun; /* when to stop culling */ 69 uint64_t fcull; /* when to start culling */ 70 uint64_t fstop; /* when to stop allocating */ 71 sector_t brun; /* when to stop culling */ 72 sector_t bcull; /* when to start culling */ 73 sector_t bstop; /* when to stop allocating */ 74 unsigned long flags; 75 #define CACHEFILES_READY 0 /* T if cache prepared */ 76 #define CACHEFILES_DEAD 1 /* T if cache dead */ 77 #define CACHEFILES_CULLING 2 /* T if cull engaged */ 78 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 79 char *rootdirname; /* name of cache root directory */ 80 char *secctx; /* LSM security context */ 81 char *tag; /* cache binding tag */ 82 }; 83 84 /* 85 * backing file read tracking 86 */ 87 struct cachefiles_one_read { 88 wait_queue_t monitor; /* link into monitored waitqueue */ 89 struct page *back_page; /* backing file page we're waiting for */ 90 struct page *netfs_page; /* netfs page we're going to fill */ 91 struct fscache_retrieval *op; /* retrieval op covering this */ 92 struct list_head op_link; /* link in op's todo list */ 93 }; 94 95 /* 96 * backing file write tracking 97 */ 98 struct cachefiles_one_write { 99 struct page *netfs_page; /* netfs page to copy */ 100 struct cachefiles_object *object; 101 struct list_head obj_link; /* link in object's lists */ 102 fscache_rw_complete_t end_io_func; 103 void *context; 104 }; 105 106 /* 107 * auxiliary data xattr buffer 108 */ 109 struct cachefiles_xattr { 110 uint16_t len; 111 uint8_t type; 112 uint8_t data[]; 113 }; 114 115 /* 116 * note change of state for daemon 117 */ 118 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 119 { 120 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 121 wake_up_all(&cache->daemon_pollwq); 122 } 123 124 /* 125 * bind.c 126 */ 127 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); 128 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); 129 130 /* 131 * daemon.c 132 */ 133 extern const struct file_operations cachefiles_daemon_fops; 134 135 extern int cachefiles_has_space(struct cachefiles_cache *cache, 136 unsigned fnr, unsigned bnr); 137 138 /* 139 * interface.c 140 */ 141 extern const struct fscache_cache_ops cachefiles_cache_ops; 142 143 /* 144 * key.c 145 */ 146 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); 147 148 /* 149 * namei.c 150 */ 151 extern int cachefiles_delete_object(struct cachefiles_cache *cache, 152 struct cachefiles_object *object); 153 extern int cachefiles_walk_to_object(struct cachefiles_object *parent, 154 struct cachefiles_object *object, 155 const char *key, 156 struct cachefiles_xattr *auxdata); 157 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 158 struct dentry *dir, 159 const char *name); 160 161 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 162 char *filename); 163 164 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 165 struct dentry *dir, char *filename); 166 167 /* 168 * proc.c 169 */ 170 #ifdef CONFIG_CACHEFILES_HISTOGRAM 171 extern atomic_t cachefiles_lookup_histogram[HZ]; 172 extern atomic_t cachefiles_mkdir_histogram[HZ]; 173 extern atomic_t cachefiles_create_histogram[HZ]; 174 175 extern int __init cachefiles_proc_init(void); 176 extern void cachefiles_proc_cleanup(void); 177 static inline 178 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif) 179 { 180 unsigned long jif = jiffies - start_jif; 181 if (jif >= HZ) 182 jif = HZ - 1; 183 atomic_inc(&histogram[jif]); 184 } 185 186 #else 187 #define cachefiles_proc_init() (0) 188 #define cachefiles_proc_cleanup() do {} while (0) 189 #define cachefiles_hist(hist, start_jif) do {} while (0) 190 #endif 191 192 /* 193 * rdwr.c 194 */ 195 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, 196 struct page *, gfp_t); 197 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, 198 struct list_head *, unsigned *, 199 gfp_t); 200 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, 201 gfp_t); 202 extern int cachefiles_allocate_pages(struct fscache_retrieval *, 203 struct list_head *, unsigned *, gfp_t); 204 extern int cachefiles_write_page(struct fscache_storage *, struct page *); 205 extern void cachefiles_uncache_page(struct fscache_object *, struct page *); 206 207 /* 208 * security.c 209 */ 210 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 211 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 212 struct dentry *root, 213 const struct cred **_saved_cred); 214 215 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 216 const struct cred **_saved_cred) 217 { 218 *_saved_cred = override_creds(cache->cache_cred); 219 } 220 221 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 222 const struct cred *saved_cred) 223 { 224 revert_creds(saved_cred); 225 } 226 227 /* 228 * xattr.c 229 */ 230 extern int cachefiles_check_object_type(struct cachefiles_object *object); 231 extern int cachefiles_set_object_xattr(struct cachefiles_object *object, 232 struct cachefiles_xattr *auxdata); 233 extern int cachefiles_update_object_xattr(struct cachefiles_object *object, 234 struct cachefiles_xattr *auxdata); 235 extern int cachefiles_check_object_xattr(struct cachefiles_object *object, 236 struct cachefiles_xattr *auxdata); 237 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 238 struct dentry *dentry); 239 240 241 /* 242 * error handling 243 */ 244 #define kerror(FMT, ...) printk(KERN_ERR "CacheFiles: "FMT"\n", ##__VA_ARGS__) 245 246 #define cachefiles_io_error(___cache, FMT, ...) \ 247 do { \ 248 kerror("I/O Error: " FMT, ##__VA_ARGS__); \ 249 fscache_io_error(&(___cache)->cache); \ 250 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 251 } while (0) 252 253 #define cachefiles_io_error_obj(object, FMT, ...) \ 254 do { \ 255 struct cachefiles_cache *___cache; \ 256 \ 257 ___cache = container_of((object)->fscache.cache, \ 258 struct cachefiles_cache, cache); \ 259 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ 260 } while (0) 261 262 263 /* 264 * debug tracing 265 */ 266 #define dbgprintk(FMT, ...) \ 267 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 268 269 /* make sure we maintain the format strings, even when debugging is disabled */ 270 static inline void _dbprintk(const char *fmt, ...) 271 __attribute__((format(printf, 1, 2))); 272 static inline void _dbprintk(const char *fmt, ...) 273 { 274 } 275 276 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 277 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 278 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 279 280 281 #if defined(__KDEBUG) 282 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 283 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 284 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 285 286 #elif defined(CONFIG_CACHEFILES_DEBUG) 287 #define _enter(FMT, ...) \ 288 do { \ 289 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 290 kenter(FMT, ##__VA_ARGS__); \ 291 } while (0) 292 293 #define _leave(FMT, ...) \ 294 do { \ 295 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 296 kleave(FMT, ##__VA_ARGS__); \ 297 } while (0) 298 299 #define _debug(FMT, ...) \ 300 do { \ 301 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 302 kdebug(FMT, ##__VA_ARGS__); \ 303 } while (0) 304 305 #else 306 #define _enter(FMT, ...) _dbprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 307 #define _leave(FMT, ...) _dbprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 308 #define _debug(FMT, ...) _dbprintk(FMT, ##__VA_ARGS__) 309 #endif 310 311 #if 1 /* defined(__KDEBUGALL) */ 312 313 #define ASSERT(X) \ 314 do { \ 315 if (unlikely(!(X))) { \ 316 printk(KERN_ERR "\n"); \ 317 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \ 318 BUG(); \ 319 } \ 320 } while (0) 321 322 #define ASSERTCMP(X, OP, Y) \ 323 do { \ 324 if (unlikely(!((X) OP (Y)))) { \ 325 printk(KERN_ERR "\n"); \ 326 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \ 327 printk(KERN_ERR "%lx " #OP " %lx is false\n", \ 328 (unsigned long)(X), (unsigned long)(Y)); \ 329 BUG(); \ 330 } \ 331 } while (0) 332 333 #define ASSERTIF(C, X) \ 334 do { \ 335 if (unlikely((C) && !(X))) { \ 336 printk(KERN_ERR "\n"); \ 337 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \ 338 BUG(); \ 339 } \ 340 } while (0) 341 342 #define ASSERTIFCMP(C, X, OP, Y) \ 343 do { \ 344 if (unlikely((C) && !((X) OP (Y)))) { \ 345 printk(KERN_ERR "\n"); \ 346 printk(KERN_ERR "CacheFiles: Assertion failed\n"); \ 347 printk(KERN_ERR "%lx " #OP " %lx is false\n", \ 348 (unsigned long)(X), (unsigned long)(Y)); \ 349 BUG(); \ 350 } \ 351 } while (0) 352 353 #else 354 355 #define ASSERT(X) do {} while (0) 356 #define ASSERTCMP(X, OP, Y) do {} while (0) 357 #define ASSERTIF(C, X) do {} while (0) 358 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 359 360 #endif 361