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_bit.h> 22 #include <linux/cred.h> 23 #include <linux/workqueue.h> 24 #include <linux/security.h> 25 26 struct cachefiles_cache; 27 struct cachefiles_object; 28 29 extern unsigned cachefiles_debug; 30 #define CACHEFILES_DEBUG_KENTER 1 31 #define CACHEFILES_DEBUG_KLEAVE 2 32 #define CACHEFILES_DEBUG_KDEBUG 4 33 34 #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC) 35 36 /* 37 * node records 38 */ 39 struct cachefiles_object { 40 struct fscache_object fscache; /* fscache handle */ 41 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */ 42 struct dentry *dentry; /* the file/dir representing this object */ 43 struct dentry *backer; /* backing file */ 44 loff_t i_size; /* object size */ 45 unsigned long flags; 46 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */ 47 atomic_t usage; /* object usage count */ 48 uint8_t type; /* object type */ 49 uint8_t new; /* T if object new */ 50 spinlock_t work_lock; 51 struct rb_node active_node; /* link in active tree (dentry is key) */ 52 }; 53 54 extern struct kmem_cache *cachefiles_object_jar; 55 56 /* 57 * Cache files cache definition 58 */ 59 struct cachefiles_cache { 60 struct fscache_cache cache; /* FS-Cache record */ 61 struct vfsmount *mnt; /* mountpoint holding the cache */ 62 struct dentry *graveyard; /* directory into which dead objects go */ 63 struct file *cachefilesd; /* manager daemon handle */ 64 const struct cred *cache_cred; /* security override for accessing cache */ 65 struct mutex daemon_mutex; /* command serialisation mutex */ 66 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ 67 struct rb_root active_nodes; /* active nodes (can't be culled) */ 68 rwlock_t active_lock; /* lock for active_nodes */ 69 atomic_t gravecounter; /* graveyard uniquifier */ 70 atomic_t f_released; /* number of objects released lately */ 71 atomic_long_t b_released; /* number of blocks released lately */ 72 unsigned frun_percent; /* when to stop culling (% files) */ 73 unsigned fcull_percent; /* when to start culling (% files) */ 74 unsigned fstop_percent; /* when to stop allocating (% files) */ 75 unsigned brun_percent; /* when to stop culling (% blocks) */ 76 unsigned bcull_percent; /* when to start culling (% blocks) */ 77 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 78 unsigned bsize; /* cache's block size */ 79 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 80 uint64_t frun; /* when to stop culling */ 81 uint64_t fcull; /* when to start culling */ 82 uint64_t fstop; /* when to stop allocating */ 83 sector_t brun; /* when to stop culling */ 84 sector_t bcull; /* when to start culling */ 85 sector_t bstop; /* when to stop allocating */ 86 unsigned long flags; 87 #define CACHEFILES_READY 0 /* T if cache prepared */ 88 #define CACHEFILES_DEAD 1 /* T if cache dead */ 89 #define CACHEFILES_CULLING 2 /* T if cull engaged */ 90 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 91 char *rootdirname; /* name of cache root directory */ 92 char *secctx; /* LSM security context */ 93 char *tag; /* cache binding tag */ 94 }; 95 96 /* 97 * backing file read tracking 98 */ 99 struct cachefiles_one_read { 100 wait_queue_entry_t monitor; /* link into monitored waitqueue */ 101 struct page *back_page; /* backing file page we're waiting for */ 102 struct page *netfs_page; /* netfs page we're going to fill */ 103 struct fscache_retrieval *op; /* retrieval op covering this */ 104 struct list_head op_link; /* link in op's todo list */ 105 }; 106 107 /* 108 * backing file write tracking 109 */ 110 struct cachefiles_one_write { 111 struct page *netfs_page; /* netfs page to copy */ 112 struct cachefiles_object *object; 113 struct list_head obj_link; /* link in object's lists */ 114 fscache_rw_complete_t end_io_func; 115 void *context; 116 }; 117 118 /* 119 * auxiliary data xattr buffer 120 */ 121 struct cachefiles_xattr { 122 uint16_t len; 123 uint8_t type; 124 uint8_t data[]; 125 }; 126 127 /* 128 * note change of state for daemon 129 */ 130 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 131 { 132 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 133 wake_up_all(&cache->daemon_pollwq); 134 } 135 136 /* 137 * bind.c 138 */ 139 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); 140 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); 141 142 /* 143 * daemon.c 144 */ 145 extern const struct file_operations cachefiles_daemon_fops; 146 147 extern int cachefiles_has_space(struct cachefiles_cache *cache, 148 unsigned fnr, unsigned bnr); 149 150 /* 151 * interface.c 152 */ 153 extern const struct fscache_cache_ops cachefiles_cache_ops; 154 155 /* 156 * key.c 157 */ 158 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); 159 160 /* 161 * namei.c 162 */ 163 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, 164 struct cachefiles_object *object, 165 blkcnt_t i_blocks); 166 extern int cachefiles_delete_object(struct cachefiles_cache *cache, 167 struct cachefiles_object *object); 168 extern int cachefiles_walk_to_object(struct cachefiles_object *parent, 169 struct cachefiles_object *object, 170 const char *key, 171 struct cachefiles_xattr *auxdata); 172 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 173 struct dentry *dir, 174 const char *name); 175 176 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 177 char *filename); 178 179 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 180 struct dentry *dir, char *filename); 181 182 /* 183 * proc.c 184 */ 185 #ifdef CONFIG_CACHEFILES_HISTOGRAM 186 extern atomic_t cachefiles_lookup_histogram[HZ]; 187 extern atomic_t cachefiles_mkdir_histogram[HZ]; 188 extern atomic_t cachefiles_create_histogram[HZ]; 189 190 extern int __init cachefiles_proc_init(void); 191 extern void cachefiles_proc_cleanup(void); 192 static inline 193 void cachefiles_hist(atomic_t histogram[], unsigned long start_jif) 194 { 195 unsigned long jif = jiffies - start_jif; 196 if (jif >= HZ) 197 jif = HZ - 1; 198 atomic_inc(&histogram[jif]); 199 } 200 201 #else 202 #define cachefiles_proc_init() (0) 203 #define cachefiles_proc_cleanup() do {} while (0) 204 #define cachefiles_hist(hist, start_jif) do {} while (0) 205 #endif 206 207 /* 208 * rdwr.c 209 */ 210 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, 211 struct page *, gfp_t); 212 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, 213 struct list_head *, unsigned *, 214 gfp_t); 215 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, 216 gfp_t); 217 extern int cachefiles_allocate_pages(struct fscache_retrieval *, 218 struct list_head *, unsigned *, gfp_t); 219 extern int cachefiles_write_page(struct fscache_storage *, struct page *); 220 extern void cachefiles_uncache_page(struct fscache_object *, struct page *); 221 222 /* 223 * security.c 224 */ 225 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 226 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 227 struct dentry *root, 228 const struct cred **_saved_cred); 229 230 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 231 const struct cred **_saved_cred) 232 { 233 *_saved_cred = override_creds(cache->cache_cred); 234 } 235 236 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 237 const struct cred *saved_cred) 238 { 239 revert_creds(saved_cred); 240 } 241 242 /* 243 * xattr.c 244 */ 245 extern int cachefiles_check_object_type(struct cachefiles_object *object); 246 extern int cachefiles_set_object_xattr(struct cachefiles_object *object, 247 struct cachefiles_xattr *auxdata); 248 extern int cachefiles_update_object_xattr(struct cachefiles_object *object, 249 struct cachefiles_xattr *auxdata); 250 extern int cachefiles_check_auxdata(struct cachefiles_object *object); 251 extern int cachefiles_check_object_xattr(struct cachefiles_object *object, 252 struct cachefiles_xattr *auxdata); 253 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 254 struct dentry *dentry); 255 256 257 /* 258 * error handling 259 */ 260 261 #define cachefiles_io_error(___cache, FMT, ...) \ 262 do { \ 263 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 264 fscache_io_error(&(___cache)->cache); \ 265 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 266 } while (0) 267 268 #define cachefiles_io_error_obj(object, FMT, ...) \ 269 do { \ 270 struct cachefiles_cache *___cache; \ 271 \ 272 ___cache = container_of((object)->fscache.cache, \ 273 struct cachefiles_cache, cache); \ 274 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ 275 } while (0) 276 277 278 /* 279 * debug tracing 280 */ 281 #define dbgprintk(FMT, ...) \ 282 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 283 284 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 285 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 286 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 287 288 289 #if defined(__KDEBUG) 290 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 291 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 292 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 293 294 #elif defined(CONFIG_CACHEFILES_DEBUG) 295 #define _enter(FMT, ...) \ 296 do { \ 297 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 298 kenter(FMT, ##__VA_ARGS__); \ 299 } while (0) 300 301 #define _leave(FMT, ...) \ 302 do { \ 303 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 304 kleave(FMT, ##__VA_ARGS__); \ 305 } while (0) 306 307 #define _debug(FMT, ...) \ 308 do { \ 309 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 310 kdebug(FMT, ##__VA_ARGS__); \ 311 } while (0) 312 313 #else 314 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 315 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 316 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 317 #endif 318 319 #if 1 /* defined(__KDEBUGALL) */ 320 321 #define ASSERT(X) \ 322 do { \ 323 if (unlikely(!(X))) { \ 324 pr_err("\n"); \ 325 pr_err("Assertion failed\n"); \ 326 BUG(); \ 327 } \ 328 } while (0) 329 330 #define ASSERTCMP(X, OP, Y) \ 331 do { \ 332 if (unlikely(!((X) OP (Y)))) { \ 333 pr_err("\n"); \ 334 pr_err("Assertion failed\n"); \ 335 pr_err("%lx " #OP " %lx is false\n", \ 336 (unsigned long)(X), (unsigned long)(Y)); \ 337 BUG(); \ 338 } \ 339 } while (0) 340 341 #define ASSERTIF(C, X) \ 342 do { \ 343 if (unlikely((C) && !(X))) { \ 344 pr_err("\n"); \ 345 pr_err("Assertion failed\n"); \ 346 BUG(); \ 347 } \ 348 } while (0) 349 350 #define ASSERTIFCMP(C, X, OP, Y) \ 351 do { \ 352 if (unlikely((C) && !((X) OP (Y)))) { \ 353 pr_err("\n"); \ 354 pr_err("Assertion failed\n"); \ 355 pr_err("%lx " #OP " %lx is false\n", \ 356 (unsigned long)(X), (unsigned long)(Y)); \ 357 BUG(); \ 358 } \ 359 } while (0) 360 361 #else 362 363 #define ASSERT(X) do {} while (0) 364 #define ASSERTCMP(X, OP, Y) do {} while (0) 365 #define ASSERTIF(C, X) do {} while (0) 366 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 367 368 #endif 369