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