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fs/adfs: map: break up adfs_read_map()

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

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Russell King 2019-12-09 11:08:39 +00:00 committed by Al Viro
parent e6160e469f
commit 6092b6be30
1 changed files with 59 additions and 21 deletions
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80
fs/adfs/map.c
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@ -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);
@ -352,34 +403,21 @@ 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) {
adfs_error(sb, "unable to read map");
goto error_free;
}
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;
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);
}