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 #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