Commit 6092b6be authored by Russell King's avatar Russell King Committed by Al Viro
Browse files

fs/adfs: map: break up adfs_read_map() 



Split up adfs_read_map() into separate helpers to layout the map,
read the map, and release the map buffers.

Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent e6160e46

fs/adfs/map.c

+59 −21
Original line number Diff line number Diff line
@@ -331,12 +331,63 @@ static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm) 
	return crosscheck == 0xff && zonecheck;

}



/*

 * Layout the map - the first zone contains a copy of the disc record,

 * and the last zone must be limited to the size of the filesystem.

 */

static void adfs_map_layout(struct adfs_discmap *dm, unsigned int nzones,

			    struct adfs_discrecord *dr)

{

	unsigned int zone, zone_size;

	u64 size;



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



	dm[0].dm_bh       = NULL;

	dm[0].dm_startblk = 0;

	dm[0].dm_startbit = ADFS_DR_SIZE_BITS;

	dm[0].dm_endbit   = zone_size;



	for (zone = 1; zone < nzones; zone++) {

		dm[zone].dm_bh       = NULL;

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

		dm[zone].dm_startbit = 0;

		dm[zone].dm_endbit   = zone_size;

	}



	size = adfs_disc_size(dr) >> dr->log2bpmb;

	size -= (nzones - 1) * zone_size - ADFS_DR_SIZE_BITS;

	dm[nzones - 1].dm_endbit = size;

}



static int adfs_map_read(struct adfs_discmap *dm, struct super_block *sb,

			 unsigned int map_addr, unsigned int nzones)

{

	unsigned int zone;



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

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

		if (!dm[zone].dm_bh)

			return -EIO;

	}



	return 0;

}



static void adfs_map_relse(struct adfs_discmap *dm, unsigned int nzones)

{

	unsigned int zone;



	for (zone = 0; zone < nzones; zone++)

		brelse(dm[zone].dm_bh);

}



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

{

	struct adfs_sb_info *asb = ADFS_SB(sb);

	struct adfs_discmap *dm;

	unsigned int map_addr, zone_size, nzones;

	int i, zone;

	struct adfs_sb_info *asb = ADFS_SB(sb);

	int ret;



	nzones    = asb->s_map_size;

	zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
@@ -352,24 +403,13 @@ struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecor 
		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);

	adfs_map_layout(dm, nzones, dr);



		if (!dm[zone].dm_bh) {

	ret = adfs_map_read(dm, sb, map_addr, nzones);

	if (ret) {

		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;
@@ -377,9 +417,7 @@ struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecor 
	adfs_error(sb, "map corrupted");



error_free:

	while (--zone >= 0)

		brelse(dm[zone].dm_bh);



	adfs_map_relse(dm, nzones);

	kfree(dm);

	return ERR_PTR(-EIO);

}