linux/fs/exfat/cache.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  linux/fs/fat/cache.c
 *
 *  Written 1992,1993 by Werner Almesberger
 *
 *  Mar 1999. AV. Changed cache, so that it uses the starting cluster instead
 *	of inode number.
 *  May 1999. AV. Fixed the bogosity with FAT32 (read "FAT28"). Fscking lusers.
 *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
 */

#include <linux/slab.h>
#include <asm/unaligned.h>
#include <linux/buffer_head.h>

#include "exfat_raw.h"
#include "exfat_fs.h"

#define EXFAT_MAX_CACHE …

struct exfat_cache { … };

struct exfat_cache_id { … };

static struct kmem_cache *exfat_cachep;

static void exfat_cache_init_once(void *c)
{ … }

int exfat_cache_init(void)
{ … }

void exfat_cache_shutdown(void)
{ … }

static inline struct exfat_cache *exfat_cache_alloc(void)
{ … }

static inline void exfat_cache_free(struct exfat_cache *cache)
{ … }

static inline void exfat_cache_update_lru(struct inode *inode,
		struct exfat_cache *cache)
{ … }

static unsigned int exfat_cache_lookup(struct inode *inode,
		unsigned int fclus, struct exfat_cache_id *cid,
		unsigned int *cached_fclus, unsigned int *cached_dclus)
{ … }

static struct exfat_cache *exfat_cache_merge(struct inode *inode,
		struct exfat_cache_id *new)
{ … }

static void exfat_cache_add(struct inode *inode,
		struct exfat_cache_id *new)
{ … }

/*
 * Cache invalidation occurs rarely, thus the LRU chain is not updated. It
 * fixes itself after a while.
 */
static void __exfat_cache_inval_inode(struct inode *inode)
{ … }

void exfat_cache_inval_inode(struct inode *inode)
{ … }

static inline int cache_contiguous(struct exfat_cache_id *cid,
		unsigned int dclus)
{ … }

static inline void cache_init(struct exfat_cache_id *cid,
		unsigned int fclus, unsigned int dclus)
{ … }

int exfat_get_cluster(struct inode *inode, unsigned int cluster,
		unsigned int *fclus, unsigned int *dclus,
		unsigned int *last_dclus, int allow_eof)
{ … }