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