/*
 * super.c
 *
 * Copyright (C) 2001-2002 Will Dyson <will_dyson@pobox.com>
 *
 * Licensed under the GNU GPL. See the file COPYING for details.
 *
 */

#include <linux/fs.h>
#include <asm/page.h> /* for PAGE_SIZE */

#include "befs.h"
#include "super.h"

/*
 * befs_load_sb -- Read from disk and properly byteswap all the fields
 * of the befs superblock
 */
int
befs_load_sb(struct super_block *sb, befs_super_block *disk_sb)
{
        struct befs_sb_info *befs_sb = BEFS_SB(sb);

        /* Check the byte order of the filesystem */
        if (disk_sb->fs_byte_order == BEFS_BYTEORDER_NATIVE_LE)
                befs_sb->byte_order = BEFS_BYTESEX_LE;
        else if (disk_sb->fs_byte_order == BEFS_BYTEORDER_NATIVE_BE)
                befs_sb->byte_order = BEFS_BYTESEX_BE;

        befs_sb->magic1 = fs32_to_cpu(sb, disk_sb->magic1);
        befs_sb->magic2 = fs32_to_cpu(sb, disk_sb->magic2);
        befs_sb->magic3 = fs32_to_cpu(sb, disk_sb->magic3);
        befs_sb->block_size = fs32_to_cpu(sb, disk_sb->block_size);
        befs_sb->block_shift = fs32_to_cpu(sb, disk_sb->block_shift);
        befs_sb->num_blocks = fs64_to_cpu(sb, disk_sb->num_blocks);
        befs_sb->used_blocks = fs64_to_cpu(sb, disk_sb->used_blocks);
        befs_sb->inode_size = fs32_to_cpu(sb, disk_sb->inode_size);

        befs_sb->blocks_per_ag = fs32_to_cpu(sb, disk_sb->blocks_per_ag);
        befs_sb->ag_shift = fs32_to_cpu(sb, disk_sb->ag_shift);
        befs_sb->num_ags = fs32_to_cpu(sb, disk_sb->num_ags);

        befs_sb->flags = fs32_to_cpu(sb, disk_sb->flags);

        befs_sb->log_blocks = fsrun_to_cpu(sb, disk_sb->log_blocks);
        befs_sb->log_start = fs64_to_cpu(sb, disk_sb->log_start);
        befs_sb->log_end = fs64_to_cpu(sb, disk_sb->log_end);

        befs_sb->root_dir = fsrun_to_cpu(sb, disk_sb->root_dir);
        befs_sb->indices = fsrun_to_cpu(sb, disk_sb->indices);
        befs_sb->nls = NULL;

        return BEFS_OK;
}

int
befs_check_sb(struct super_block *sb)
{
        struct befs_sb_info *befs_sb = BEFS_SB(sb);

        /* Check magic headers of super block */
        if ((befs_sb->magic1 != BEFS_SUPER_MAGIC1)
            || (befs_sb->magic2 != BEFS_SUPER_MAGIC2)
            || (befs_sb->magic3 != BEFS_SUPER_MAGIC3)) {
                befs_error(sb, "invalid magic header");
                return BEFS_ERR;
        }

        /*
         * Check blocksize of BEFS.
         *
         * Blocksize of BEFS is 1024, 2048, 4096 or 8192.
         */

        if ((befs_sb->block_size != 1024)
            && (befs_sb->block_size != 2048)
            && (befs_sb->block_size != 4096)
            && (befs_sb->block_size != 8192)) {
                befs_error(sb, "invalid blocksize: %u", befs_sb->block_size);
                return BEFS_ERR;
        }

        if (befs_sb->block_size > PAGE_SIZE) {
                befs_error(sb, "blocksize(%u) cannot be larger "
                           "than system pagesize(%lu)", befs_sb->block_size,
                           PAGE_SIZE);
                return BEFS_ERR;
        }

        /*
         * block_shift and block_size encode the same information
         * in different ways as a consistency check.
         */

        if ((1 << befs_sb->block_shift) != befs_sb->block_size) {
                befs_error(sb, "block_shift disagrees with block_size. "
                           "Corruption likely.");
                return BEFS_ERR;
        }


        /* ag_shift also encodes the same information as blocks_per_ag in a
         * different way, non-fatal consistency check
         */
        if ((1 << befs_sb->ag_shift) != befs_sb->blocks_per_ag)
                befs_error(sb, "ag_shift disagrees with blocks_per_ag.");

        if (befs_sb->log_start != befs_sb->log_end ||
            befs_sb->flags == BEFS_DIRTY) {
                befs_error(sb, "Filesystem not clean! There are blocks in the "
                           "journal. You must boot into BeOS and mount this "
                           "volume to make it clean.");
                return BEFS_ERR;
        }

        return BEFS_OK;
}