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 #ifdef pr_fmt 13 #undef pr_fmt 14 #endif 15 16 #define pr_fmt(fmt) "CacheFiles: " fmt 17 18 19 #include <linux/fscache-cache.h> 20 #include <linux/timer.h> 21 #include <linux/wait.h> 22 #include <linux/workqueue.h> 23 #include <linux/security.h> 24 25 struct cachefiles_cache; 26 struct cachefiles_object; 27 28 extern unsigned cachefiles_debug; 29 #define CACHEFILES_DEBUG_KENTER 1 30 #define CACHEFILES_DEBUG_KLEAVE 2 31 #define CACHEFILES_DEBUG_KDEBUG 4 32 33 #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC) 34 35 /* 36 * node records 37 */ 38 struct cachefiles_object { 39 struct fscache_object fscache; /* fscache handle */ 40 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */ 41 struct dentry *dentry; /* the file/dir representing this object */ 42 struct dentry *backer; /* backing file */ 43 loff_t i_size; /* object size */ 44 unsigned long flags; 45 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */ 46 atomic_t usage; /* object usage count */ 47 uint8_t type; /* object type */ 48 uint8_t new; /* T if object new */ 49 spinlock_t work_lock; 50 struct rb_node active_node; /* link in active tree (dentry is key) */ 51 }; 52 53 extern struct kmem_cache *cachefiles_object_jar; 54 55 /* 56 * Cache files cache definition 57 */ 58 struct cachefiles_cache { 59 struct fscache_cache cache; /* FS-Cache record */ 60 struct vfsmount *mnt; /* mountpoint holding the cache */ 61 struct dentry *graveyard; /* directory into which dead objects go */ 62 struct file *cachefilesd; /* manager daemon handle */ 63 const struct cred *cache_cred; /* security override for accessing cache */ 64 struct mutex daemon_mutex; /* command serialisation mutex */ 65 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ 66 struct rb_root active_nodes; /* active nodes (can't be culled) */ 67 rwlock_t active_lock; /* lock for active_nodes */ 68 atomic_t gravecounter; /* graveyard uniquifier */ 69 unsigned frun_percent; /* when to stop culling (% files) */ 70 unsigned fcull_percent; /* when to start culling (% files) */ 71 unsigned fstop_percent; /* when to stop allocating (% files) */ 72 unsigned brun_percent; /* when to stop culling (% blocks) */ 73 unsigned bcull_percent; /* when to start culling (% blocks) */ 74 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 75 unsigned bsize; /* cache's block size */ 76 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 77 uint64_t frun; /* when to stop culling */ 78 uint64_t fcull; /* when to start culling */ 79 uint64_t fstop; /* when to stop allocating */ 80 sector_t brun; /* when to stop culling */ 81 sector_t bcull; /* when to start culling */ 82 sector_t bstop; /* when to stop allocating */ 83 unsigned long flags; 84 #define CACHEFILES_READY 0 /* T if cache prepared */ 85 #define CACHEFILES_DEAD 1 /* T if cache dead */ 86 #define CACHEFILES_CULLING 2 /* T if cull engaged */ 87 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 88 char *rootdirname; /* name of cache root directory */ 89 char *secctx; /* LSM security context */ 90 char *tag; /* cache binding tag */ 91 }; 92 93 /* 94 * backing file read tracking 95 */ 96 struct cachefiles_one_read { 97 wait_queue_t monitor; /* link into monitored waitqueue */ 98 struct page *back_page; /* backing file page we're waiting for */ 99 struct page *netfs_page; /* netfs page we're going to fill */ 100 struct fscache_retrieval *op; /* retrieval op covering this */ 101 struct list_head op_link; /* link in op's todo list */ 102 }; 103 104 /* 105 * backing file write tracking 106 */ 107 struct cachefiles_one_write { 108 struct page *netfs_page; /* netfs page to copy */ 109 struct cachefiles_object *object; 110 struct list_head obj_link; /* link in object's lists */ 111 fscache_rw_complete_t end_io_func; 112 void *context; 113 }; 114 115 /* 116 * auxiliary data xattr buffer 117 */ 118 struct cachefiles_xattr { 119 uint16_t len; 120 uint8_t type; 121 uint8_t data[]; 122 }; 123 124 /* 125 * note change of state for daemon 126 */ 127 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 128 { 129 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 130 wake_up_all(&cache->daemon_pollwq); 131 } 132 133 /* 134 * bind.c 135 */ 136 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); 137 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); 138 139 /* 140 * daemon.c 141 */ 142 extern const struct file_operations cachefiles_daemon_fops; 143 144 extern int cachefiles_has_space(struct cachefiles_cache *cache, 145 unsigned fnr, unsigned bnr); 146 147 /* 148 * interface.c 149 */ 150 extern const struct fscache_cache_ops cachefiles_cache_ops; 151 152 /* 153 * key.c 154 */ 155 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); 156 157 /* 158 * namei.c 159 */ 160 extern int cachefiles_delete_object(struct cachefiles_cache *cache, 161 struct cachefiles_object *object); 162 extern int cachefiles_walk_to_object(struct cachefiles_object *parent, 163 struct cachefiles_object *object, 164 const char *key, 165 struct cachefiles_xattr *auxdata); 166 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 167 struct dentry *dir, 168 const char *name); 169 170 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 171 char *filename); 172 173 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 174 struct dentry *dir, char *filename); 175 176 /* 177 * proc.c 178 */ 179 #ifdef CONFIG_CACHEFILES_HISTOGRAM 180 extern atomic_t cachefiles_lookup_histogram[HZ]; 181 extern atomic_t cachefiles_mkdir_histogram[HZ]; 182 extern atomic_t cachefiles_create_histogram[HZ]; 183 184 extern int __init cachefiles_proc_init(void); 185 extern void cachefiles_proc_cleanup(void); 186 static inline 187 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif) 188 { 189 unsigned long jif = jiffies - start_jif; 190 if (jif >= HZ) 191 jif = HZ - 1; 192 atomic_inc(&histogram[jif]); 193 } 194 195 #else 196 #define cachefiles_proc_init() (0) 197 #define cachefiles_proc_cleanup() do {} while (0) 198 #define cachefiles_hist(hist, start_jif) do {} while (0) 199 #endif 200 201 /* 202 * rdwr.c 203 */ 204 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, 205 struct page *, gfp_t); 206 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, 207 struct list_head *, unsigned *, 208 gfp_t); 209 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, 210 gfp_t); 211 extern int cachefiles_allocate_pages(struct fscache_retrieval *, 212 struct list_head *, unsigned *, gfp_t); 213 extern int cachefiles_write_page(struct fscache_storage *, struct page *); 214 extern void cachefiles_uncache_page(struct fscache_object *, struct page *); 215 216 /* 217 * security.c 218 */ 219 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 220 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 221 struct dentry *root, 222 const struct cred **_saved_cred); 223 224 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 225 const struct cred **_saved_cred) 226 { 227 *_saved_cred = override_creds(cache->cache_cred); 228 } 229 230 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 231 const struct cred *saved_cred) 232 { 233 revert_creds(saved_cred); 234 } 235 236 /* 237 * xattr.c 238 */ 239 extern int cachefiles_check_object_type(struct cachefiles_object *object); 240 extern int cachefiles_set_object_xattr(struct cachefiles_object *object, 241 struct cachefiles_xattr *auxdata); 242 extern int cachefiles_update_object_xattr(struct cachefiles_object *object, 243 struct cachefiles_xattr *auxdata); 244 extern int cachefiles_check_auxdata(struct cachefiles_object *object); 245 extern int cachefiles_check_object_xattr(struct cachefiles_object *object, 246 struct cachefiles_xattr *auxdata); 247 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 248 struct dentry *dentry); 249 250 251 /* 252 * error handling 253 */ 254 255 #define cachefiles_io_error(___cache, FMT, ...) \ 256 do { \ 257 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 258 fscache_io_error(&(___cache)->cache); \ 259 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 260 } while (0) 261 262 #define cachefiles_io_error_obj(object, FMT, ...) \ 263 do { \ 264 struct cachefiles_cache *___cache; \ 265 \ 266 ___cache = container_of((object)->fscache.cache, \ 267 struct cachefiles_cache, cache); \ 268 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ 269 } while (0) 270 271 272 /* 273 * debug tracing 274 */ 275 #define dbgprintk(FMT, ...) \ 276 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 277 278 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 279 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 280 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 281 282 283 #if defined(__KDEBUG) 284 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 285 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 286 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 287 288 #elif defined(CONFIG_CACHEFILES_DEBUG) 289 #define _enter(FMT, ...) \ 290 do { \ 291 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 292 kenter(FMT, ##__VA_ARGS__); \ 293 } while (0) 294 295 #define _leave(FMT, ...) \ 296 do { \ 297 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 298 kleave(FMT, ##__VA_ARGS__); \ 299 } while (0) 300 301 #define _debug(FMT, ...) \ 302 do { \ 303 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 304 kdebug(FMT, ##__VA_ARGS__); \ 305 } while (0) 306 307 #else 308 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 309 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 310 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 311 #endif 312 313 #if 1 /* defined(__KDEBUGALL) */ 314 315 #define ASSERT(X) \ 316 do { \ 317 if (unlikely(!(X))) { \ 318 pr_err("\n"); \ 319 pr_err("Assertion failed\n"); \ 320 BUG(); \ 321 } \ 322 } while (0) 323 324 #define ASSERTCMP(X, OP, Y) \ 325 do { \ 326 if (unlikely(!((X) OP (Y)))) { \ 327 pr_err("\n"); \ 328 pr_err("Assertion failed\n"); \ 329 pr_err("%lx " #OP " %lx is false\n", \ 330 (unsigned long)(X), (unsigned long)(Y)); \ 331 BUG(); \ 332 } \ 333 } while (0) 334 335 #define ASSERTIF(C, X) \ 336 do { \ 337 if (unlikely((C) && !(X))) { \ 338 pr_err("\n"); \ 339 pr_err("Assertion failed\n"); \ 340 BUG(); \ 341 } \ 342 } while (0) 343 344 #define ASSERTIFCMP(C, X, OP, Y) \ 345 do { \ 346 if (unlikely((C) && !((X) OP (Y)))) { \ 347 pr_err("\n"); \ 348 pr_err("Assertion failed\n"); \ 349 pr_err("%lx " #OP " %lx is false\n", \ 350 (unsigned long)(X), (unsigned long)(Y)); \ 351 BUG(); \ 352 } \ 353 } while (0) 354 355 #else 356 357 #define ASSERT(X) do {} while (0) 358 #define ASSERTCMP(X, OP, Y) do {} while (0) 359 #define ASSERTIF(C, X) do {} while (0) 360 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 361 362 #endif 363