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