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 atomic_t f_released; /* number of objects released lately */ 70 atomic_long_t b_released; /* number of blocks released lately */ 71 unsigned frun_percent; /* when to stop culling (% files) */ 72 unsigned fcull_percent; /* when to start culling (% files) */ 73 unsigned fstop_percent; /* when to stop allocating (% files) */ 74 unsigned brun_percent; /* when to stop culling (% blocks) */ 75 unsigned bcull_percent; /* when to start culling (% blocks) */ 76 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 77 unsigned bsize; /* cache's block size */ 78 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 79 uint64_t frun; /* when to stop culling */ 80 uint64_t fcull; /* when to start culling */ 81 uint64_t fstop; /* when to stop allocating */ 82 sector_t brun; /* when to stop culling */ 83 sector_t bcull; /* when to start culling */ 84 sector_t bstop; /* when to stop allocating */ 85 unsigned long flags; 86 #define CACHEFILES_READY 0 /* T if cache prepared */ 87 #define CACHEFILES_DEAD 1 /* T if cache dead */ 88 #define CACHEFILES_CULLING 2 /* T if cull engaged */ 89 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 90 char *rootdirname; /* name of cache root directory */ 91 char *secctx; /* LSM security context */ 92 char *tag; /* cache binding tag */ 93 }; 94 95 /* 96 * backing file read tracking 97 */ 98 struct cachefiles_one_read { 99 wait_queue_t monitor; /* link into monitored waitqueue */ 100 struct page *back_page; /* backing file page we're waiting for */ 101 struct page *netfs_page; /* netfs page we're going to fill */ 102 struct fscache_retrieval *op; /* retrieval op covering this */ 103 struct list_head op_link; /* link in op's todo list */ 104 }; 105 106 /* 107 * backing file write tracking 108 */ 109 struct cachefiles_one_write { 110 struct page *netfs_page; /* netfs page to copy */ 111 struct cachefiles_object *object; 112 struct list_head obj_link; /* link in object's lists */ 113 fscache_rw_complete_t end_io_func; 114 void *context; 115 }; 116 117 /* 118 * auxiliary data xattr buffer 119 */ 120 struct cachefiles_xattr { 121 uint16_t len; 122 uint8_t type; 123 uint8_t data[]; 124 }; 125 126 /* 127 * note change of state for daemon 128 */ 129 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 130 { 131 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 132 wake_up_all(&cache->daemon_pollwq); 133 } 134 135 /* 136 * bind.c 137 */ 138 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); 139 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); 140 141 /* 142 * daemon.c 143 */ 144 extern const struct file_operations cachefiles_daemon_fops; 145 146 extern int cachefiles_has_space(struct cachefiles_cache *cache, 147 unsigned fnr, unsigned bnr); 148 149 /* 150 * interface.c 151 */ 152 extern const struct fscache_cache_ops cachefiles_cache_ops; 153 154 /* 155 * key.c 156 */ 157 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); 158 159 /* 160 * namei.c 161 */ 162 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, 163 struct cachefiles_object *object, 164 blkcnt_t i_blocks); 165 extern int cachefiles_delete_object(struct cachefiles_cache *cache, 166 struct cachefiles_object *object); 167 extern int cachefiles_walk_to_object(struct cachefiles_object *parent, 168 struct cachefiles_object *object, 169 const char *key, 170 struct cachefiles_xattr *auxdata); 171 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 172 struct dentry *dir, 173 const char *name); 174 175 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 176 char *filename); 177 178 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 179 struct dentry *dir, char *filename); 180 181 /* 182 * proc.c 183 */ 184 #ifdef CONFIG_CACHEFILES_HISTOGRAM 185 extern atomic_t cachefiles_lookup_histogram[HZ]; 186 extern atomic_t cachefiles_mkdir_histogram[HZ]; 187 extern atomic_t cachefiles_create_histogram[HZ]; 188 189 extern int __init cachefiles_proc_init(void); 190 extern void cachefiles_proc_cleanup(void); 191 static inline 192 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif) 193 { 194 unsigned long jif = jiffies - start_jif; 195 if (jif >= HZ) 196 jif = HZ - 1; 197 atomic_inc(&histogram[jif]); 198 } 199 200 #else 201 #define cachefiles_proc_init() (0) 202 #define cachefiles_proc_cleanup() do {} while (0) 203 #define cachefiles_hist(hist, start_jif) do {} while (0) 204 #endif 205 206 /* 207 * rdwr.c 208 */ 209 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, 210 struct page *, gfp_t); 211 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, 212 struct list_head *, unsigned *, 213 gfp_t); 214 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, 215 gfp_t); 216 extern int cachefiles_allocate_pages(struct fscache_retrieval *, 217 struct list_head *, unsigned *, gfp_t); 218 extern int cachefiles_write_page(struct fscache_storage *, struct page *); 219 extern void cachefiles_uncache_page(struct fscache_object *, struct page *); 220 221 /* 222 * security.c 223 */ 224 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 225 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 226 struct dentry *root, 227 const struct cred **_saved_cred); 228 229 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 230 const struct cred **_saved_cred) 231 { 232 *_saved_cred = override_creds(cache->cache_cred); 233 } 234 235 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 236 const struct cred *saved_cred) 237 { 238 revert_creds(saved_cred); 239 } 240 241 /* 242 * xattr.c 243 */ 244 extern int cachefiles_check_object_type(struct cachefiles_object *object); 245 extern int cachefiles_set_object_xattr(struct cachefiles_object *object, 246 struct cachefiles_xattr *auxdata); 247 extern int cachefiles_update_object_xattr(struct cachefiles_object *object, 248 struct cachefiles_xattr *auxdata); 249 extern int cachefiles_check_auxdata(struct cachefiles_object *object); 250 extern int cachefiles_check_object_xattr(struct cachefiles_object *object, 251 struct cachefiles_xattr *auxdata); 252 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 253 struct dentry *dentry); 254 255 256 /* 257 * error handling 258 */ 259 260 #define cachefiles_io_error(___cache, FMT, ...) \ 261 do { \ 262 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 263 fscache_io_error(&(___cache)->cache); \ 264 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 265 } while (0) 266 267 #define cachefiles_io_error_obj(object, FMT, ...) \ 268 do { \ 269 struct cachefiles_cache *___cache; \ 270 \ 271 ___cache = container_of((object)->fscache.cache, \ 272 struct cachefiles_cache, cache); \ 273 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ 274 } while (0) 275 276 277 /* 278 * debug tracing 279 */ 280 #define dbgprintk(FMT, ...) \ 281 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 282 283 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 284 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 285 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 286 287 288 #if defined(__KDEBUG) 289 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 290 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 291 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 292 293 #elif defined(CONFIG_CACHEFILES_DEBUG) 294 #define _enter(FMT, ...) \ 295 do { \ 296 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 297 kenter(FMT, ##__VA_ARGS__); \ 298 } while (0) 299 300 #define _leave(FMT, ...) \ 301 do { \ 302 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 303 kleave(FMT, ##__VA_ARGS__); \ 304 } while (0) 305 306 #define _debug(FMT, ...) \ 307 do { \ 308 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 309 kdebug(FMT, ##__VA_ARGS__); \ 310 } while (0) 311 312 #else 313 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 314 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 315 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 316 #endif 317 318 #if 1 /* defined(__KDEBUGALL) */ 319 320 #define ASSERT(X) \ 321 do { \ 322 if (unlikely(!(X))) { \ 323 pr_err("\n"); \ 324 pr_err("Assertion failed\n"); \ 325 BUG(); \ 326 } \ 327 } while (0) 328 329 #define ASSERTCMP(X, OP, Y) \ 330 do { \ 331 if (unlikely(!((X) OP (Y)))) { \ 332 pr_err("\n"); \ 333 pr_err("Assertion failed\n"); \ 334 pr_err("%lx " #OP " %lx is false\n", \ 335 (unsigned long)(X), (unsigned long)(Y)); \ 336 BUG(); \ 337 } \ 338 } while (0) 339 340 #define ASSERTIF(C, X) \ 341 do { \ 342 if (unlikely((C) && !(X))) { \ 343 pr_err("\n"); \ 344 pr_err("Assertion failed\n"); \ 345 BUG(); \ 346 } \ 347 } while (0) 348 349 #define ASSERTIFCMP(C, X, OP, Y) \ 350 do { \ 351 if (unlikely((C) && !((X) OP (Y)))) { \ 352 pr_err("\n"); \ 353 pr_err("Assertion failed\n"); \ 354 pr_err("%lx " #OP " %lx is false\n", \ 355 (unsigned long)(X), (unsigned long)(Y)); \ 356 BUG(); \ 357 } \ 358 } while (0) 359 360 #else 361 362 #define ASSERT(X) do {} while (0) 363 #define ASSERTCMP(X, OP, Y) do {} while (0) 364 #define ASSERTIF(C, X) do {} while (0) 365 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 366 367 #endif 368