linux/fs/hfsplus/wrapper.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/hfsplus/wrapper.c
 *
 * Copyright (C) 2001
 * Brad Boyer ([email protected])
 * (C) 2003 Ardis Technologies <[email protected]>
 *
 * Handling of HFS wrappers around HFS+ volumes
 */

#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/cdrom.h>
#include <linux/unaligned.h>

#include "hfsplus_fs.h"
#include "hfsplus_raw.h"

struct hfsplus_wd { … };

/**
 * hfsplus_submit_bio - Perform block I/O
 * @sb: super block of volume for I/O
 * @sector: block to read or write, for blocks of HFSPLUS_SECTOR_SIZE bytes
 * @buf: buffer for I/O
 * @data: output pointer for location of requested data
 * @opf: I/O operation type and flags
 *
 * The unit of I/O is hfsplus_min_io_size(sb), which may be bigger than
 * HFSPLUS_SECTOR_SIZE, and @buf must be sized accordingly. On reads
 * @data will return a pointer to the start of the requested sector,
 * which may not be the same location as @buf.
 *
 * If @sector is not aligned to the bdev logical block size it will
 * be rounded down. For writes this means that @buf should contain data
 * that starts at the rounded-down address. As long as the data was
 * read using hfsplus_submit_bio() and the same buffer is used things
 * will work correctly.
 *
 * Returns: %0 on success else -errno code
 */
int hfsplus_submit_bio(struct super_block *sb, sector_t sector,
		       void *buf, void **data, blk_opf_t opf)
{ … }

static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
{ … }

static int hfsplus_get_last_session(struct super_block *sb,
				    sector_t *start, sector_t *size)
{ … }

/* Find the volume header and fill in some minimum bits in superblock */
/* Takes in super block, returns true if good data read */
int hfsplus_read_wrapper(struct super_block *sb)
{ … }