openwrtv4/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_squashfs.c

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/*
* Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
* Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/magic.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/byteorder/generic.h>
#include "mtdsplit.h"
static int
mtdsplit_parse_squashfs(struct mtd_info *master,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct mtd_partition *part;
struct mtd_info *parent_mtd;
size_t part_offset;
size_t squashfs_len;
int err;
err = mtd_get_squashfs_len(master, 0, &squashfs_len);
if (err)
return err;
parent_mtd = mtdpart_get_master(master);
part_offset = mtdpart_get_offset(master);
part = kzalloc(sizeof(*part), GFP_KERNEL);
if (!part) {
pr_alert("unable to allocate memory for \"%s\" partition\n",
ROOTFS_SPLIT_NAME);
return -ENOMEM;
}
part->name = ROOTFS_SPLIT_NAME;
part->offset = mtd_roundup_to_eb(part_offset + squashfs_len,
parent_mtd) - part_offset;
part->size = mtd_rounddown_to_eb(master->size - part->offset, master);
*pparts = part;
return 1;
}
static struct mtd_part_parser mtdsplit_squashfs_parser = {
.owner = THIS_MODULE,
.name = "squashfs-split",
.parse_fn = mtdsplit_parse_squashfs,
.type = MTD_PARSER_TYPE_ROOTFS,
};
static int __init mtdsplit_squashfs_init(void)
{
register_mtd_parser(&mtdsplit_squashfs_parser);
return 0;
}
subsys_initcall(mtdsplit_squashfs_init);