Commit f75d398d authored by Russell King's avatar Russell King Committed by Al Viro
Browse files

fs/adfs: map: move map reading and validation to map.c 



Keep all the map code together in map.c, rather than having some in
super.c

Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 81916245

fs/adfs/adfs.h

+1 −0
Original line number Diff line number Diff line
@@ -146,6 +146,7 @@ int adfs_notify_change(struct dentry *dentry, struct iattr *attr); 
/* map.c */

int adfs_map_lookup(struct super_block *sb, u32 frag_id, unsigned int offset);

extern unsigned int adfs_map_free(struct super_block *sb);

struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr);



/* Misc */

__printf(3, 4)

fs/adfs/map.c

+99 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 *

 *  Copyright (C) 1997-2002 Russell King

 */

#include <linux/slab.h>

#include <asm/unaligned.h>

#include "adfs.h"
@@ -280,3 +281,101 @@ bad_fragment: 
		   frag_id, zone, asb->s_map_size);

	return 0;

}



static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)

{

	unsigned int v0, v1, v2, v3;

	int i;



	v0 = v1 = v2 = v3 = 0;

	for (i = sb->s_blocksize - 4; i; i -= 4) {

		v0 += map[i]     + (v3 >> 8);

		v3 &= 0xff;

		v1 += map[i + 1] + (v0 >> 8);

		v0 &= 0xff;

		v2 += map[i + 2] + (v1 >> 8);

		v1 &= 0xff;

		v3 += map[i + 3] + (v2 >> 8);

		v2 &= 0xff;

	}

	v0 +=           v3 >> 8;

	v1 += map[1] + (v0 >> 8);

	v2 += map[2] + (v1 >> 8);

	v3 += map[3] + (v2 >> 8);



	return v0 ^ v1 ^ v2 ^ v3;

}



static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)

{

	unsigned char crosscheck = 0, zonecheck = 1;

	int i;



	for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {

		unsigned char *map;



		map = dm[i].dm_bh->b_data;



		if (adfs_calczonecheck(sb, map) != map[0]) {

			adfs_error(sb, "zone %d fails zonecheck", i);

			zonecheck = 0;

		}

		crosscheck ^= map[3];

	}

	if (crosscheck != 0xff)

		adfs_error(sb, "crosscheck != 0xff");

	return crosscheck == 0xff && zonecheck;

}



struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)

{

	struct adfs_discmap *dm;

	unsigned int map_addr, zone_size, nzones;

	int i, zone;

	struct adfs_sb_info *asb = ADFS_SB(sb);



	nzones    = asb->s_map_size;

	zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);

	map_addr  = (nzones >> 1) * zone_size -

		     ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);

	map_addr  = signed_asl(map_addr, asb->s_map2blk);



	asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);



	dm = kmalloc_array(nzones, sizeof(*dm), GFP_KERNEL);

	if (dm == NULL) {

		adfs_error(sb, "not enough memory");

		return ERR_PTR(-ENOMEM);

	}



	for (zone = 0; zone < nzones; zone++, map_addr++) {

		dm[zone].dm_startbit = 0;

		dm[zone].dm_endbit   = zone_size;

		dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;

		dm[zone].dm_bh       = sb_bread(sb, map_addr);



		if (!dm[zone].dm_bh) {

			adfs_error(sb, "unable to read map");

			goto error_free;

		}

	}



	/* adjust the limits for the first and last map zones */

	i = zone - 1;

	dm[0].dm_startblk = 0;

	dm[0].dm_startbit = ADFS_DR_SIZE_BITS;

	dm[i].dm_endbit   = (adfs_disc_size(dr) >> dr->log2bpmb) +

			    (ADFS_DR_SIZE_BITS - i * zone_size);



	if (adfs_checkmap(sb, dm))

		return dm;



	adfs_error(sb, "map corrupted");



error_free:

	while (--zone >= 0)

		brelse(dm[zone].dm_bh);



	kfree(dm);

	return ERR_PTR(-EIO);

}

fs/adfs/super.c

+0 −98
Original line number Diff line number Diff line
@@ -88,51 +88,6 @@ static int adfs_checkdiscrecord(struct adfs_discrecord *dr) 
	return 0;

}



static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)

{

	unsigned int v0, v1, v2, v3;

	int i;



	v0 = v1 = v2 = v3 = 0;

	for (i = sb->s_blocksize - 4; i; i -= 4) {

		v0 += map[i]     + (v3 >> 8);

		v3 &= 0xff;

		v1 += map[i + 1] + (v0 >> 8);

		v0 &= 0xff;

		v2 += map[i + 2] + (v1 >> 8);

		v1 &= 0xff;

		v3 += map[i + 3] + (v2 >> 8);

		v2 &= 0xff;

	}

	v0 +=           v3 >> 8;

	v1 += map[1] + (v0 >> 8);

	v2 += map[2] + (v1 >> 8);

	v3 += map[3] + (v2 >> 8);



	return v0 ^ v1 ^ v2 ^ v3;

}



static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)

{

	unsigned char crosscheck = 0, zonecheck = 1;

	int i;



	for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {

		unsigned char *map;



		map = dm[i].dm_bh->b_data;



		if (adfs_calczonecheck(sb, map) != map[0]) {

			adfs_error(sb, "zone %d fails zonecheck", i);

			zonecheck = 0;

		}

		crosscheck ^= map[3];

	}

	if (crosscheck != 0xff)

		adfs_error(sb, "crosscheck != 0xff");

	return crosscheck == 0xff && zonecheck;

}



static void adfs_put_super(struct super_block *sb)

{

	int i;
@@ -322,59 +277,6 @@ static const struct super_operations adfs_sops = { 
	.show_options	= adfs_show_options,

};



static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)

{

	struct adfs_discmap *dm;

	unsigned int map_addr, zone_size, nzones;

	int i, zone;

	struct adfs_sb_info *asb = ADFS_SB(sb);



	nzones    = asb->s_map_size;

	zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);

	map_addr  = (nzones >> 1) * zone_size -

		     ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);

	map_addr  = signed_asl(map_addr, asb->s_map2blk);



	asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);



	dm = kmalloc_array(nzones, sizeof(*dm), GFP_KERNEL);

	if (dm == NULL) {

		adfs_error(sb, "not enough memory");

		return ERR_PTR(-ENOMEM);

	}



	for (zone = 0; zone < nzones; zone++, map_addr++) {

		dm[zone].dm_startbit = 0;

		dm[zone].dm_endbit   = zone_size;

		dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;

		dm[zone].dm_bh       = sb_bread(sb, map_addr);



		if (!dm[zone].dm_bh) {

			adfs_error(sb, "unable to read map");

			goto error_free;

		}

	}



	/* adjust the limits for the first and last map zones */

	i = zone - 1;

	dm[0].dm_startblk = 0;

	dm[0].dm_startbit = ADFS_DR_SIZE_BITS;

	dm[i].dm_endbit   = (adfs_disc_size(dr) >> dr->log2bpmb) +

			    (ADFS_DR_SIZE_BITS - i * zone_size);



	if (adfs_checkmap(sb, dm))

		return dm;



	adfs_error(sb, "map corrupted");



error_free:

	while (--zone >= 0)

		brelse(dm[zone].dm_bh);



	kfree(dm);

	return ERR_PTR(-EIO);

}



static int adfs_fill_super(struct super_block *sb, void *data, int silent)

{

	struct adfs_discrecord *dr;

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