original development tree for Linux kernel GTP module; now long in mainline.
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/* General netfs cache on cache files internal defs
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/fscache-cache.h>
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/security.h>
struct cachefiles_cache;
struct cachefiles_object;
extern unsigned cachefiles_debug;
#define CACHEFILES_DEBUG_KENTER 1
#define CACHEFILES_DEBUG_KLEAVE 2
#define CACHEFILES_DEBUG_KDEBUG 4
#define cachefiles_gfp (__GFP_WAIT | __GFP_NORETRY | __GFP_NOMEMALLOC)
/*
* node records
*/
struct cachefiles_object {
struct fscache_object fscache; /* fscache handle */
struct cachefiles_lookup_data *lookup_data; /* cached lookup data */
struct dentry *dentry; /* the file/dir representing this object */
struct dentry *backer; /* backing file */
loff_t i_size; /* object size */
unsigned long flags;
#define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */
#define CACHEFILES_OBJECT_BURIED 1 /* T if preemptively buried */
atomic_t usage; /* object usage count */
uint8_t type; /* object type */
uint8_t new; /* T if object new */
spinlock_t work_lock;
struct rb_node active_node; /* link in active tree (dentry is key) */
};
extern struct kmem_cache *cachefiles_object_jar;
/*
* Cache files cache definition
*/
struct cachefiles_cache {
struct fscache_cache cache; /* FS-Cache record */
struct vfsmount *mnt; /* mountpoint holding the cache */
struct dentry *graveyard; /* directory into which dead objects go */
struct file *cachefilesd; /* manager daemon handle */
const struct cred *cache_cred; /* security override for accessing cache */
struct mutex daemon_mutex; /* command serialisation mutex */
wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
struct rb_root active_nodes; /* active nodes (can't be culled) */
rwlock_t active_lock; /* lock for active_nodes */
atomic_t gravecounter; /* graveyard uniquifier */
unsigned frun_percent; /* when to stop culling (% files) */
unsigned fcull_percent; /* when to start culling (% files) */
unsigned fstop_percent; /* when to stop allocating (% files) */
unsigned brun_percent; /* when to stop culling (% blocks) */
unsigned bcull_percent; /* when to start culling (% blocks) */
unsigned bstop_percent; /* when to stop allocating (% blocks) */
unsigned bsize; /* cache's block size */
unsigned bshift; /* min(ilog2(PAGE_SIZE / bsize), 0) */
uint64_t frun; /* when to stop culling */
uint64_t fcull; /* when to start culling */
uint64_t fstop; /* when to stop allocating */
sector_t brun; /* when to stop culling */
sector_t bcull; /* when to start culling */
sector_t bstop; /* when to stop allocating */
unsigned long flags;
#define CACHEFILES_READY 0 /* T if cache prepared */
#define CACHEFILES_DEAD 1 /* T if cache dead */
#define CACHEFILES_CULLING 2 /* T if cull engaged */
#define CACHEFILES_STATE_CHANGED 3 /* T if state changed (poll trigger) */
char *rootdirname; /* name of cache root directory */
char *secctx; /* LSM security context */
char *tag; /* cache binding tag */
};
/*
* backing file read tracking
*/
struct cachefiles_one_read {
wait_queue_t monitor; /* link into monitored waitqueue */
struct page *back_page; /* backing file page we're waiting for */
struct page *netfs_page; /* netfs page we're going to fill */
struct fscache_retrieval *op; /* retrieval op covering this */
struct list_head op_link; /* link in op's todo list */
};
/*
* backing file write tracking
*/
struct cachefiles_one_write {
struct page *netfs_page; /* netfs page to copy */
struct cachefiles_object *object;
struct list_head obj_link; /* link in object's lists */
fscache_rw_complete_t end_io_func;
void *context;
};
/*
* auxiliary data xattr buffer
*/
struct cachefiles_xattr {
uint16_t len;
uint8_t type;
uint8_t data[];
};
/*
* note change of state for daemon
*/
static inline void cachefiles_state_changed(struct cachefiles_cache *cache)
{
set_bit(CACHEFILES_STATE_CHANGED, &cache->flags);
wake_up_all(&cache->daemon_pollwq);
}
/*
* bind.c
*/
extern int cachefiles_daemon_bind(struct cachefiles_cache *cache, char *args);
extern void cachefiles_daemon_unbind(struct cachefiles_cache *cache);
/*
* daemon.c
*/
extern const struct file_operations cachefiles_daemon_fops;
extern int cachefiles_has_space(struct cachefiles_cache *cache,
unsigned fnr, unsigned bnr);
/*
* interface.c
*/
extern const struct fscache_cache_ops cachefiles_cache_ops;
/*
* key.c
*/
extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
/*
* namei.c
*/
extern int cachefiles_delete_object(struct cachefiles_cache *cache,
struct cachefiles_object *object);
extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
struct cachefiles_object *object,
const char *key,
struct cachefiles_xattr *auxdata);
extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
struct dentry *dir,
const char *name);
extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
char *filename);
extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
struct dentry *dir, char *filename);
/*
* proc.c
*/
#ifdef CONFIG_CACHEFILES_HISTOGRAM
extern atomic_t cachefiles_lookup_histogram[HZ];
extern atomic_t cachefiles_mkdir_histogram[HZ];
extern atomic_t cachefiles_create_histogram[HZ];
extern int __init cachefiles_proc_init(void);
extern void cachefiles_proc_cleanup(void);
static inline
void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
{
unsigned long jif = jiffies - start_jif;
if (jif >= HZ)
jif = HZ - 1;
atomic_inc(&histogram[jif]);
}
#else
#define cachefiles_proc_init() (0)
#define cachefiles_proc_cleanup() do {} while (0)
#define cachefiles_hist(hist, start_jif) do {} while (0)
#endif
/*
* rdwr.c
*/
extern int cachefiles_read_or_alloc_page(struct fscache_retrieval *,
struct page *, gfp_t);
extern int cachefiles_read_or_alloc_pages(struct fscache_retrieval *,
struct list_head *, unsigned *,
gfp_t);
extern int cachefiles_allocate_page(struct fscache_retrieval *, struct page *,
gfp_t);
extern int cachefiles_allocate_pages(struct fscache_retrieval *,
struct list_head *, unsigned *, gfp_t);
extern int cachefiles_write_page(struct fscache_storage *, struct page *);
extern void cachefiles_uncache_page(struct fscache_object *, struct page *);
/*
* security.c
*/
extern int cachefiles_get_security_ID(struct cachefiles_cache *cache);
extern int cachefiles_determine_cache_security(struct cachefiles_cache *cache,
struct dentry *root,
const struct cred **_saved_cred);
static inline void cachefiles_begin_secure(struct cachefiles_cache *cache,
const struct cred **_saved_cred)
{
*_saved_cred = override_creds(cache->cache_cred);
}
static inline void cachefiles_end_secure(struct cachefiles_cache *cache,
const struct cred *saved_cred)
{
revert_creds(saved_cred);
}
/*
* xattr.c
*/
extern int cachefiles_check_object_type(struct cachefiles_object *object);
extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
struct cachefiles_xattr *auxdata);
extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
struct cachefiles_xattr *auxdata);
extern int cachefiles_check_auxdata(struct cachefiles_object *object);
extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
struct cachefiles_xattr *auxdata);
extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
struct dentry *dentry);
/*
* error handling
*/
#define kerror(FMT, ...) printk(KERN_ERR "CacheFiles: "FMT"\n", ##__VA_ARGS__)
#define cachefiles_io_error(___cache, FMT, ...) \
do { \
kerror("I/O Error: " FMT, ##__VA_ARGS__); \
fscache_io_error(&(___cache)->cache); \
set_bit(CACHEFILES_DEAD, &(___cache)->flags); \
} while (0)
#define cachefiles_io_error_obj(object, FMT, ...) \
do { \
struct cachefiles_cache *___cache; \
\
___cache = container_of((object)->fscache.cache, \
struct cachefiles_cache, cache); \
cachefiles_io_error(___cache, FMT, ##__VA_ARGS__); \
} while (0)
/*
* debug tracing
*/
#define dbgprintk(FMT, ...) \
printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
#if defined(__KDEBUG)
#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
#elif defined(CONFIG_CACHEFILES_DEBUG)
#define _enter(FMT, ...) \
do { \
if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \
kenter(FMT, ##__VA_ARGS__); \
} while (0)
#define _leave(FMT, ...) \
do { \
if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \
kleave(FMT, ##__VA_ARGS__); \
} while (0)
#define _debug(FMT, ...) \
do { \
if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \
kdebug(FMT, ##__VA_ARGS__); \
} while (0)
#else
#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
#endif
#if 1 /* defined(__KDEBUGALL) */
#define ASSERT(X) \
do { \
if (unlikely(!(X))) { \
printk(KERN_ERR "\n"); \
printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
BUG(); \
} \
} while (0)
#define ASSERTCMP(X, OP, Y) \
do { \
if (unlikely(!((X) OP (Y)))) { \
printk(KERN_ERR "\n"); \
printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
printk(KERN_ERR "%lx " #OP " %lx is false\n", \
(unsigned long)(X), (unsigned long)(Y)); \
BUG(); \
} \
} while (0)
#define ASSERTIF(C, X) \
do { \
if (unlikely((C) && !(X))) { \
printk(KERN_ERR "\n"); \
printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
BUG(); \
} \
} while (0)
#define ASSERTIFCMP(C, X, OP, Y) \
do { \
if (unlikely((C) && !((X) OP (Y)))) { \
printk(KERN_ERR "\n"); \
printk(KERN_ERR "CacheFiles: Assertion failed\n"); \
printk(KERN_ERR "%lx " #OP " %lx is false\n", \
(unsigned long)(X), (unsigned long)(Y)); \
BUG(); \
} \
} while (0)
#else
#define ASSERT(X) do {} while (0)
#define ASSERTCMP(X, OP, Y) do {} while (0)
#define ASSERTIF(C, X) do {} while (0)
#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
#endif