LXR linux/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
  26struct cachefiles_cache;
  27struct cachefiles_object;
  28
  29extern 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 */
  39struct 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
  54extern struct kmem_cache *cachefiles_object_jar;
  55
  56/*
  57 * Cache files cache definition
  58 */
  59struct 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 */
  99struct 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 */
 110struct 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 */
 121struct cachefiles_xattr {
 122        uint16_t                        len;
 123        uint8_t                         type;
 124        uint8_t                         data[];
 125};
 126
 127#include <trace/events/cachefiles.h>
 128
 129/*
 130 * note change of state for daemon
 131 */
 132static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
 133{
 134        set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
 135        wake_up_all(&cache->daemon_pollwq);
 136}
 137
 138/*
 139 * bind.c
 140 */
 141extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
 142extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
 143
 144/*
 145 * daemon.c
 146 */
 147extern const struct file_operations cachefiles_daemon_fops;
 148
 149extern int cachefiles_has_space(struct cachefiles_cache *cache,
 150                                unsigned fnr, unsigned bnr);
 151
 152/*
 153 * interface.c
 154 */
 155extern const struct fscache_cache_ops cachefiles_cache_ops;
 156
 157/*
 158 * key.c
 159 */
 160extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
 161
 162/*
 163 * namei.c
 164 */
 165extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
 166                                            struct cachefiles_object *object,
 167                                            blkcnt_t i_blocks);
 168extern int cachefiles_delete_object(struct cachefiles_cache *cache,
 169                                    struct cachefiles_object *object);
 170extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
 171                                     struct cachefiles_object *object,
 172                                     const char *key,
 173                                     struct cachefiles_xattr *auxdata);
 174extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 175                                               struct dentry *dir,
 176                                               const char *name);
 177
 178extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
 179                           char *filename);
 180
 181extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
 182                                   struct dentry *dir, char *filename);
 183
 184/*
 185 * proc.c
 186 */
 187#ifdef CONFIG_CACHEFILES_HISTOGRAM
 188extern atomic_t cachefiles_lookup_histogram[HZ];
 189extern atomic_t cachefiles_mkdir_histogram[HZ];
 190extern atomic_t cachefiles_create_histogram[HZ];
 191
 192extern int __init cachefiles_proc_init(void);
 193extern void cachefiles_proc_cleanup(void);
 194static inline
 195void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
 196{
 197        unsigned long jif = jiffies - start_jif;
 198        if (jif >= HZ)
 199                jif = HZ - 1;
 200        atomic_inc(&histogram[jif]);
 201}
 202
 203#else
 204#define cachefiles_proc_init()          (0)
 205#define cachefiles_proc_cleanup()       do {} while (0)
 206#define cachefiles_hist(hist, start_jif) do {} while (0)
 207#endif
 208
 209/*
 210 * rdwr.c
 211 */
 212extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
 213                                         struct page *, gfp_t);
 214extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
 215                                          struct list_head *, unsigned *,
 216                                          gfp_t);
 217extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
 218                                    gfp_t);
 219extern int cachefiles_allocate_pages(struct fscache_retrieval *,
 220                                     struct list_head *, unsigned *, gfp_t);
 221extern int cachefiles_write_page(struct fscache_storage *, struct page *);
 222extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
 223
 224/*
 225 * security.c
 226 */
 227extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
 228extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
 229                                               struct dentry *root,
 230                                               const struct cred **_saved_cred);
 231
 232static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
 233                                           const struct cred **_saved_cred)
 234{
 235        *_saved_cred = override_creds(cache->cache_cred);
 236}
 237
 238static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
 239                                         const struct cred *saved_cred)
 240{
 241        revert_creds(saved_cred);
 242}
 243
 244/*
 245 * xattr.c
 246 */
 247extern int cachefiles_check_object_type(struct cachefiles_object *object);
 248extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
 249                                       struct cachefiles_xattr *auxdata);
 250extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
 251                                          struct cachefiles_xattr *auxdata);
 252extern int cachefiles_check_auxdata(struct cachefiles_object *object);
 253extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
 254                                         struct cachefiles_xattr *auxdata);
 255extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
 256                                          struct dentry *dentry);
 257
 258
 259/*
 260 * error handling
 261 */
 262
 263#define cachefiles_io_error(___cache, FMT, ...)         \
 264do {                                                    \
 265        pr_err("I/O Error: " FMT"\n", ##__VA_ARGS__);   \
 266        fscache_io_error(&(___cache)->cache);           \
 267        set_bit(CACHEFILES_DEAD, &(___cache)->flags);   \
 268} while (0)
 269
 270#define cachefiles_io_error_obj(object, FMT, ...)                       \
 271do {                                                                    \
 272        struct cachefiles_cache *___cache;                              \
 273                                                                        \
 274        ___cache = container_of((object)->fscache.cache,                \
 275                                struct cachefiles_cache, cache);        \
 276        cachefiles_io_error(___cache, FMT, ##__VA_ARGS__);              \
 277} while (0)
 278
 279
 280/*
 281 * debug tracing
 282 */
 283#define dbgprintk(FMT, ...) \
 284        printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
 285
 286#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 287#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 288#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
 289
 290
 291#if defined(__KDEBUG)
 292#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
 293#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
 294#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
 295
 296#elif defined(CONFIG_CACHEFILES_DEBUG)
 297#define _enter(FMT, ...)                                \
 298do {                                                    \
 299        if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
 300                kenter(FMT, ##__VA_ARGS__);             \
 301} while (0)
 302
 303#define _leave(FMT, ...)                                \
 304do {                                                    \
 305        if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
 306                kleave(FMT, ##__VA_ARGS__);             \
 307} while (0)
 308
 309#define _debug(FMT, ...)                                \
 310do {                                                    \
 311        if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
 312                kdebug(FMT, ##__VA_ARGS__);             \
 313} while (0)
 314
 315#else
 316#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
 317#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
 318#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
 319#endif
 320
 321#if 1 /* defined(__KDEBUGALL) */
 322
 323#define ASSERT(X)                                                       \
 324do {                                                                    \
 325        if (unlikely(!(X))) {                                           \
 326                pr_err("\n");                                           \
 327                pr_err("Assertion failed\n");           \
 328                BUG();                                                  \
 329        }                                                               \
 330} while (0)
 331
 332#define ASSERTCMP(X, OP, Y)                                             \
 333do {                                                                    \
 334        if (unlikely(!((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#define ASSERTIF(C, X)                                                  \
 344do {                                                                    \
 345        if (unlikely((C) && !(X))) {                                    \
 346                pr_err("\n");                                           \
 347                pr_err("Assertion failed\n");           \
 348                BUG();                                                  \
 349        }                                                               \
 350} while (0)
 351
 352#define ASSERTIFCMP(C, X, OP, Y)                                        \
 353do {                                                                    \
 354        if (unlikely((C) && !((X) OP (Y)))) {                           \
 355                pr_err("\n");                                           \
 356                pr_err("Assertion failed\n");           \
 357                pr_err("%lx " #OP " %lx is false\n",                    \
 358                       (unsigned long)(X), (unsigned long)(Y));         \
 359                BUG();                                                  \
 360        }                                                               \
 361} while (0)
 362
 363#else
 364
 365#define ASSERT(X)                       do {} while (0)
 366#define ASSERTCMP(X, OP, Y)             do {} while (0)
 367#define ASSERTIF(C, X)                  do {} while (0)
 368#define ASSERTIFCMP(C, X, OP, Y)        do {} while (0)
 369
 370#endif
 371