linux/fs/hfs/extent.c

/*
 *  linux/fs/hfs/extent.c
 *
 * Copyright (C) 1995-1997  Paul H. Hargrove
 * (C) 2003 Ardis Technologies <[email protected]>
 * This file may be distributed under the terms of the GNU General Public License.
 *
 * This file contains the functions related to the extents B-tree.
 */

#include <linux/pagemap.h>

#include "hfs_fs.h"
#include "btree.h"

/*================ File-local functions ================*/

/*
 * build_key
 */
static void hfs_ext_build_key(hfs_btree_key *key, u32 cnid, u16 block, u8 type)
{ … }

/*
 * hfs_ext_compare()
 *
 * Description:
 *   This is the comparison function used for the extents B-tree.  In
 *   comparing extent B-tree entries, the file id is the most
 *   significant field (compared as unsigned ints); the fork type is
 *   the second most significant field (compared as unsigned chars);
 *   and the allocation block number field is the least significant
 *   (compared as unsigned ints).
 * Input Variable(s):
 *   struct hfs_ext_key *key1: pointer to the first key to compare
 *   struct hfs_ext_key *key2: pointer to the second key to compare
 * Output Variable(s):
 *   NONE
 * Returns:
 *   int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
 * Preconditions:
 *   key1 and key2 point to "valid" (struct hfs_ext_key)s.
 * Postconditions:
 *   This function has no side-effects */
int hfs_ext_keycmp(const btree_key *key1, const btree_key *key2)
{ … }

/*
 * hfs_ext_find_block
 *
 * Find a block within an extent record
 */
static u16 hfs_ext_find_block(struct hfs_extent *ext, u16 off)
{ … }

static int hfs_ext_block_count(struct hfs_extent *ext)
{ … }

static u16 hfs_ext_lastblock(struct hfs_extent *ext)
{ … }

static int __hfs_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
{ … }

int hfs_ext_write_extent(struct inode *inode)
{ … }

static inline int __hfs_ext_read_extent(struct hfs_find_data *fd, struct hfs_extent *extent,
					u32 cnid, u32 block, u8 type)
{ … }

static inline int __hfs_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
{ … }

static int hfs_ext_read_extent(struct inode *inode, u16 block)
{ … }

static void hfs_dump_extent(struct hfs_extent *extent)
{ … }

static int hfs_add_extent(struct hfs_extent *extent, u16 offset,
			  u16 alloc_block, u16 block_count)
{ … }

static int hfs_free_extents(struct super_block *sb, struct hfs_extent *extent,
			    u16 offset, u16 block_nr)
{ … }

int hfs_free_fork(struct super_block *sb, struct hfs_cat_file *file, int type)
{ … }

/*
 * hfs_get_block
 */
int hfs_get_block(struct inode *inode, sector_t block,
		  struct buffer_head *bh_result, int create)
{ … }

int hfs_extend_file(struct inode *inode)
{ … }

void hfs_file_truncate(struct inode *inode)
{ … }