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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/fs/befs/super.c
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/*

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 * super.c

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 *

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 * Copyright (C) 2001-2002 Will Dyson <[email protected]>

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 *

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 * Licensed under the GNU GPL. See the file COPYING for details.

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 *

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 */

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#include <linux/fs.h>

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

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#include "befs.h"

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#include "super.h"

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/*

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 * befs_load_sb -- Read from disk and properly byteswap all the fields

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 * of the befs superblock

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 */

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int

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befs_load_sb(struct super_block *sb, befs_super_block *disk_sb)

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{

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	struct befs_sb_info *befs_sb = BEFS_SB(sb);

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	/* Check the byte order of the filesystem */

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	if (disk_sb->fs_byte_order == BEFS_BYTEORDER_NATIVE_LE)

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		befs_sb->byte_order = BEFS_BYTESEX_LE;

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	else if (disk_sb->fs_byte_order == BEFS_BYTEORDER_NATIVE_BE)

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		befs_sb->byte_order = BEFS_BYTESEX_BE;

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	befs_sb->magic1 = fs32_to_cpu(sb, disk_sb->magic1);

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	befs_sb->magic2 = fs32_to_cpu(sb, disk_sb->magic2);

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	befs_sb->magic3 = fs32_to_cpu(sb, disk_sb->magic3);

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

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

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	befs_sb->num_blocks = fs64_to_cpu(sb, disk_sb->num_blocks);

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	befs_sb->used_blocks = fs64_to_cpu(sb, disk_sb->used_blocks);

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

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

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

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

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

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

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

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

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

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

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	befs_sb->nls = NULL;

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	return BEFS_OK;

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}

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int

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befs_check_sb(struct super_block *sb)

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{

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	struct befs_sb_info *befs_sb = BEFS_SB(sb);

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	/* Check magic headers of super block */

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	if ((befs_sb->magic1 != BEFS_SUPER_MAGIC1)

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	    || (befs_sb->magic2 != BEFS_SUPER_MAGIC2)

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	    || (befs_sb->magic3 != BEFS_SUPER_MAGIC3)) {

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		befs_error(sb, "invalid magic header");

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		return BEFS_ERR;

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	}

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	/*

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	 * Check blocksize of BEFS.

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	 *

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

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	 */

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	if ((befs_sb->block_size != 1024)

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	    && (befs_sb->block_size != 2048)

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	    && (befs_sb->block_size != 4096)

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	    && (befs_sb->block_size != 8192)) {

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		befs_error(sb, "invalid blocksize: %u", befs_sb->block_size);

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		return BEFS_ERR;

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	}

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	if (befs_sb->block_size > PAGE_SIZE) {

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		befs_error(sb, "blocksize(%u) cannot be larger "

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			   "than system pagesize(%lu)", befs_sb->block_size,

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			   PAGE_SIZE);

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		return BEFS_ERR;

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	}

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	/*

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	 * block_shift and block_size encode the same information

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	 * in different ways as a consistency check.

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	 */

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	if ((1 << befs_sb->block_shift) != befs_sb->block_size) {

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		befs_error(sb, "block_shift disagrees with block_size. "

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			   "Corruption likely.");

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		return BEFS_ERR;

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	}

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	/* ag_shift also encodes the same information as blocks_per_ag in a

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	 * different way, non-fatal consistency check

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	 */

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	if ((1 << befs_sb->ag_shift) != befs_sb->blocks_per_ag)

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		befs_error(sb, "ag_shift disagrees with blocks_per_ag.");

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	if (befs_sb->log_start != befs_sb->log_end ||

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	    befs_sb->flags == BEFS_DIRTY) {

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		befs_error(sb, "Filesystem not clean! There are blocks in the "

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			   "journal. You must boot into BeOS and mount this "

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			   "volume to make it clean.");

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		return BEFS_ERR;

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	}

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	return BEFS_OK;

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}

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