fs/cachefiles/internal.h

   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_object_xattr(struct cachefiles_object *object,
 239                                          struct cachefiles_xattr *auxdata);
 240 extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
 241                                           struct dentry *dentry);
 242
 243
 244 /*
 245  * error handling
 246  */
 247 #define kerror(FMT, ...) printk(KERN_ERR "CacheFiles: "FMT"\n", ##__VA_ARGS__)
 248
 249 #define cachefiles_io_error(___cache, FMT, ...)         \
 250 do {                                                    \
 251         kerror("I/O Error: " FMT, ##__VA_ARGS__);       \
 252         fscache_io_error(&(___cache)->cache);           \
 253         set_bit(CACHEFILES_DEAD, &(___cache)->flags);   \
 254 } while (0)
 255
 256 #define cachefiles_io_error_obj(object, FMT, ...)                       \
 257 do {                                                                    \
 258         struct cachefiles_cache *___cache;                              \
 259                                                                         \
 260         ___cache = container_of((object)->fscache.cache,                \
 261                                 struct cachefiles_cache, cache);        \
 262         cachefiles_io_error(___cache, FMT, ##__VA_ARGS__);              \
 263 } while (0)
 264
 265
 266 /*
 267  * debug tracing
 268  */
 269 #define dbgprintk(FMT, ...) \
 270         printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 271
 272 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 273 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 274 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 275
 276
 277 #if defined(__KDEBUG)
 278 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 279 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 280 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 281
 282 #elif defined(CONFIG_CACHEFILES_DEBUG)
 283 #define _enter(FMT, ...)                                \
 284 do {                                                    \
 285         if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
 286                 kenter(FMT, ##__VA_ARGS__);             \
 287 } while (0)
 288
 289 #define _leave(FMT, ...)                                \
 290 do {                                                    \
 291         if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
 292                 kleave(FMT, ##__VA_ARGS__);             \
 293 } while (0)
 294
 295 #define _debug(FMT, ...)                                \
 296 do {                                                    \
 297         if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
 298                 kdebug(FMT, ##__VA_ARGS__);             \
 299 } while (0)
 300
 301 #else
 302 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 303 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 304 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 305 #endif
 306
 307 #if 1 /* defined(__KDEBUGALL) */
 308
 309 #define ASSERT(X)                                                       \
 310 do {                                                                    \
 311         if (unlikely(!(X))) {                                           \
 312                 printk(KERN_ERR "\n");                                  \
 313                 printk(KERN_ERR "CacheFiles: Assertion failed\n");      \
 314                 BUG();                                                  \
 315         }                                                               \
 316 } while (0)
 317
 318 #define ASSERTCMP(X, OP, Y)                                             \
 319 do {                                                                    \
 320         if (unlikely(!((X) OP (Y)))) {                                  \
 321                 printk(KERN_ERR "\n");                                  \
 322                 printk(KERN_ERR "CacheFiles: Assertion failed\n");      \
 323                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 324                        (unsigned long)(X), (unsigned long)(Y));         \
 325                 BUG();                                                  \
 326         }                                                               \
 327 } while (0)
 328
 329 #define ASSERTIF(C, X)                                                  \
 330 do {                                                                    \
 331         if (unlikely((C) && !(X))) {                                    \
 332                 printk(KERN_ERR "\n");                                  \
 333                 printk(KERN_ERR "CacheFiles: Assertion failed\n");      \
 334                 BUG();                                                  \
 335         }                                                               \
 336 } while (0)
 337
 338 #define ASSERTIFCMP(C, X, OP, Y)                                        \
 339 do {                                                                    \
 340         if (unlikely((C) && !((X) OP (Y)))) {                           \
 341                 printk(KERN_ERR "\n");                                  \
 342                 printk(KERN_ERR "CacheFiles: Assertion failed\n");      \
 343                 printk(KERN_ERR "%lx " #OP " %lx is false\n",           \
 344                        (unsigned long)(X), (unsigned long)(Y));         \
 345                 BUG();                                                  \
 346         }                                                               \
 347 } while (0)
 348
 349 #else
 350
 351 #define ASSERT(X)                       do {} while (0)
 352 #define ASSERTCMP(X, OP, Y)             do {} while (0)
 353 #define ASSERTIF(C, X)                  do {} while (0)
 354 #define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 355
 356 #endif