1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* General netfs cache on cache files internal defs 3 * 4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #ifdef pr_fmt 9 #undef pr_fmt 10 #endif 11 12 #define pr_fmt(fmt) "CacheFiles: " fmt 13 14 15 #include <linux/fscache-cache.h> 16 #include <linux/timer.h> 17 #include <linux/wait_bit.h> 18 #include <linux/cred.h> 19 #include <linux/workqueue.h> 20 #include <linux/security.h> 21 22 struct cachefiles_cache; 23 struct cachefiles_object; 24 25 extern unsigned cachefiles_debug; 26 #define CACHEFILES_DEBUG_KENTER 1 27 #define CACHEFILES_DEBUG_KLEAVE 2 28 #define CACHEFILES_DEBUG_KDEBUG 4 29 30 #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC) 31 32 /* 33 * node records 34 */ 35 struct cachefiles_object { 36 struct fscache_object fscache; /* fscache handle */ 37 struct cachefiles_lookup_data *lookup_data; /* cached lookup data */ 38 struct dentry *dentry; /* the file/dir representing this object */ 39 struct dentry *backer; /* backing file */ 40 loff_t i_size; /* object size */ 41 unsigned long flags; 42 #define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */ 43 atomic_t usage; /* object usage count */ 44 uint8_t type; /* object type */ 45 uint8_t new; /* T if object new */ 46 spinlock_t work_lock; 47 struct rb_node active_node; /* link in active tree (dentry is key) */ 48 }; 49 50 extern struct kmem_cache *cachefiles_object_jar; 51 52 /* 53 * Cache files cache definition 54 */ 55 struct cachefiles_cache { 56 struct fscache_cache cache; /* FS-Cache record */ 57 struct vfsmount *mnt; /* mountpoint holding the cache */ 58 struct dentry *graveyard; /* directory into which dead objects go */ 59 struct file *cachefilesd; /* manager daemon handle */ 60 const struct cred *cache_cred; /* security override for accessing cache */ 61 struct mutex daemon_mutex; /* command serialisation mutex */ 62 wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */ 63 struct rb_root active_nodes; /* active nodes (can't be culled) */ 64 rwlock_t active_lock; /* lock for active_nodes */ 65 atomic_t gravecounter; /* graveyard uniquifier */ 66 atomic_t f_released; /* number of objects released lately */ 67 atomic_long_t b_released; /* number of blocks released lately */ 68 unsigned frun_percent; /* when to stop culling (% files) */ 69 unsigned fcull_percent; /* when to start culling (% files) */ 70 unsigned fstop_percent; /* when to stop allocating (% files) */ 71 unsigned brun_percent; /* when to stop culling (% blocks) */ 72 unsigned bcull_percent; /* when to start culling (% blocks) */ 73 unsigned bstop_percent; /* when to stop allocating (% blocks) */ 74 unsigned bsize; /* cache's block size */ 75 unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */ 76 uint64_t frun; /* when to stop culling */ 77 uint64_t fcull; /* when to start culling */ 78 uint64_t fstop; /* when to stop allocating */ 79 sector_t brun; /* when to stop culling */ 80 sector_t bcull; /* when to start culling */ 81 sector_t bstop; /* when to stop allocating */ 82 unsigned long flags; 83 #define CACHEFILES_READY 0 /* T if cache prepared */ 84 #define CACHEFILES_DEAD 1 /* T if cache dead */ 85 #define CACHEFILES_CULLING 2 /* T if cull engaged */ 86 #define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */ 87 char *rootdirname; /* name of cache root directory */ 88 char *secctx; /* LSM security context */ 89 char *tag; /* cache binding tag */ 90 }; 91 92 /* 93 * backing file read tracking 94 */ 95 struct cachefiles_one_read { 96 wait_queue_entry_t monitor; /* link into monitored waitqueue */ 97 struct page *back_page; /* backing file page we're waiting for */ 98 struct page *netfs_page; /* netfs page we're going to fill */ 99 struct fscache_retrieval *op; /* retrieval op covering this */ 100 struct list_head op_link; /* link in op's todo list */ 101 }; 102 103 /* 104 * backing file write tracking 105 */ 106 struct cachefiles_one_write { 107 struct page *netfs_page; /* netfs page to copy */ 108 struct cachefiles_object *object; 109 struct list_head obj_link; /* link in object's lists */ 110 fscache_rw_complete_t end_io_func; 111 void *context; 112 }; 113 114 /* 115 * auxiliary data xattr buffer 116 */ 117 struct cachefiles_xattr { 118 uint16_t len; 119 uint8_t type; 120 uint8_t data[]; 121 }; 122 123 #include <trace/events/cachefiles.h> 124 125 /* 126 * note change of state for daemon 127 */ 128 static inline void cachefiles_state_changed(struct cachefiles_cache *cache) 129 { 130 set_bit(CACHEFILES_STATE_CHANGED, &cache->flags); 131 wake_up_all(&cache->daemon_pollwq); 132 } 133 134 /* 135 * bind.c 136 */ 137 extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args); 138 extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache); 139 140 /* 141 * daemon.c 142 */ 143 extern const struct file_operations cachefiles_daemon_fops; 144 145 extern int cachefiles_has_space(struct cachefiles_cache *cache, 146 unsigned fnr, unsigned bnr); 147 148 /* 149 * interface.c 150 */ 151 extern const struct fscache_cache_ops cachefiles_cache_ops; 152 153 void cachefiles_put_object(struct fscache_object *_object, 154 enum fscache_obj_ref_trace why); 155 156 /* 157 * key.c 158 */ 159 extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type); 160 161 /* 162 * namei.c 163 */ 164 extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, 165 struct cachefiles_object *object, 166 blkcnt_t i_blocks); 167 extern int cachefiles_delete_object(struct cachefiles_cache *cache, 168 struct cachefiles_object *object); 169 extern int cachefiles_walk_to_object(struct cachefiles_object *parent, 170 struct cachefiles_object *object, 171 const char *key, 172 struct cachefiles_xattr *auxdata); 173 extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, 174 struct dentry *dir, 175 const char *name); 176 177 extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 178 char *filename); 179 180 extern int cachefiles_check_in_use(struct cachefiles_cache *cache, 181 struct dentry *dir, char *filename); 182 183 /* 184 * rdwr.c 185 */ 186 extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *, 187 struct page *, gfp_t); 188 extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *, 189 struct list_head *, unsigned *, 190 gfp_t); 191 extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *, 192 gfp_t); 193 extern int cachefiles_allocate_pages(struct fscache_retrieval *, 194 struct list_head *, unsigned *, gfp_t); 195 extern int cachefiles_write_page(struct fscache_storage *, struct page *); 196 extern void cachefiles_uncache_page(struct fscache_object *, struct page *); 197 198 /* 199 * rdwr2.c 200 */ 201 extern int cachefiles_begin_read_operation(struct netfs_read_request *, 202 struct fscache_retrieval *); 203 204 /* 205 * security.c 206 */ 207 extern int cachefiles_get_security_ID(struct cachefiles_cache *cache); 208 extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache, 209 struct dentry *root, 210 const struct cred **_saved_cred); 211 212 static inline void cachefiles_begin_secure(struct cachefiles_cache *cache, 213 const struct cred **_saved_cred) 214 { 215 *_saved_cred = override_creds(cache->cache_cred); 216 } 217 218 static inline void cachefiles_end_secure(struct cachefiles_cache *cache, 219 const struct cred *saved_cred) 220 { 221 revert_creds(saved_cred); 222 } 223 224 /* 225 * xattr.c 226 */ 227 extern int cachefiles_check_object_type(struct cachefiles_object *object); 228 extern int cachefiles_set_object_xattr(struct cachefiles_object *object, 229 struct cachefiles_xattr *auxdata); 230 extern int cachefiles_update_object_xattr(struct cachefiles_object *object, 231 struct cachefiles_xattr *auxdata); 232 extern int cachefiles_check_auxdata(struct cachefiles_object *object); 233 extern int cachefiles_check_object_xattr(struct cachefiles_object *object, 234 struct cachefiles_xattr *auxdata); 235 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, 236 struct dentry *dentry); 237 238 239 /* 240 * error handling 241 */ 242 243 #define cachefiles_io_error(___cache, FMT, ...) \ 244 do { \ 245 pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__); \ 246 fscache_io_error(&(___cache)->cache); \ 247 set_bit(CACHEFILES_DEAD, &(___cache)->flags); \ 248 } while (0) 249 250 #define cachefiles_io_error_obj(object, FMT, ...) \ 251 do { \ 252 struct cachefiles_cache *___cache; \ 253 \ 254 ___cache = container_of((object)->fscache.cache, \ 255 struct cachefiles_cache, cache); \ 256 cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \ 257 } while (0) 258 259 260 /* 261 * debug tracing 262 */ 263 #define dbgprintk(FMT, ...) \ 264 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) 265 266 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) 267 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 268 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) 269 270 271 #if defined(__KDEBUG) 272 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) 273 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) 274 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) 275 276 #elif defined(CONFIG_CACHEFILES_DEBUG) 277 #define _enter(FMT, ...) \ 278 do { \ 279 if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ 280 kenter(FMT, ##__VA_ARGS__); \ 281 } while (0) 282 283 #define _leave(FMT, ...) \ 284 do { \ 285 if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ 286 kleave(FMT, ##__VA_ARGS__); \ 287 } while (0) 288 289 #define _debug(FMT, ...) \ 290 do { \ 291 if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ 292 kdebug(FMT, ##__VA_ARGS__); \ 293 } while (0) 294 295 #else 296 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) 297 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) 298 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) 299 #endif 300 301 #if 1 /* defined(__KDEBUGALL) */ 302 303 #define ASSERT(X) \ 304 do { \ 305 if (unlikely(!(X))) { \ 306 pr_err("\n"); \ 307 pr_err("Assertion failed\n"); \ 308 BUG(); \ 309 } \ 310 } while (0) 311 312 #define ASSERTCMP(X, OP, Y) \ 313 do { \ 314 if (unlikely(!((X) OP (Y)))) { \ 315 pr_err("\n"); \ 316 pr_err("Assertion failed\n"); \ 317 pr_err("%lx " #OP " %lx is false\n", \ 318 (unsigned long)(X), (unsigned long)(Y)); \ 319 BUG(); \ 320 } \ 321 } while (0) 322 323 #define ASSERTIF(C, X) \ 324 do { \ 325 if (unlikely((C) && !(X))) { \ 326 pr_err("\n"); \ 327 pr_err("Assertion failed\n"); \ 328 BUG(); \ 329 } \ 330 } while (0) 331 332 #define ASSERTIFCMP(C, X, OP, Y) \ 333 do { \ 334 if (unlikely((C) && !((X) OP (Y)))) { \ 335 pr_err("\n"); \ 336 pr_err("Assertion failed\n"); \ 337 pr_err("%lx " #OP " %lx is false\n", \ 338 (unsigned long)(X), (unsigned long)(Y)); \ 339 BUG(); \ 340 } \ 341 } while (0) 342 343 #else 344 345 #define ASSERT(X) do {} while (0) 346 #define ASSERTCMP(X, OP, Y) do {} while (0) 347 #define ASSERTIF(C, X) do {} while (0) 348 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0) 349 350 #endif 351