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/*
* linux/fs/adfs/super.c
*
* Copyright (C) 1997-1999 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/version.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/adfs_fs.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/locks.h>
#include <linux/init.h>
#include <asm/bitops.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <stdarg.h>
#include "adfs.h"
#include "dir_f.h"
#include "dir_fplus.h"
void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
{
char error_buf[128];
va_list args;
va_start(args, fmt);
vsprintf(error_buf, fmt, args);
va_end(args);
printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
bdevname(sb->s_dev), function ? ": " : "",
function ? function : "", error_buf);
}
static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
{
int i;
/* sector size must be 256, 512 or 1024 bytes */
if (dr->log2secsize != 8 &&
dr->log2secsize != 9 &&
dr->log2secsize != 10)
return 1;
/* idlen must be at least log2secsize + 3 */
if (dr->idlen < dr->log2secsize + 3)
return 1;
/* we cannot have such a large disc that we
* are unable to represent sector offsets in
* 32 bits. This works out at 2.0 TB.
*/
if (dr->disc_size_high >> dr->log2secsize)
return 1;
/*
* The following checks are not required for F+
* stage 1.
*/
#if 0
/* idlen must be smaller be no greater than 15 */
if (dr->idlen > 15)
return 1;
/* nzones must be less than 128 for the root
* directory to be addressable
*/
if (dr->nzones >= 128 && dr->nzones_high == 0)
return 1;
/* root must be of the form 0x2.. */
if ((le32_to_cpu(dr->root) & 0xffffff00) != 0x00000200)
return 1;
#else
/*
* Stage 2 F+ does not require the following check
*/
#if 0
/* idlen must be no greater than 16 v2 [1.0] */
if (dr->idlen > 16)
return 1;
/* we can't handle F+ discs yet */
if (dr->format_version || dr->root_size)
return 1;
#else
/* idlen must be no greater than 19 v2 [1.0] */
if (dr->idlen > 19)
return 1;
#endif
#endif
/* reserved bytes should be zero */
for (i = 0; i < sizeof(dr->unused52); i++)
if (dr->unused52[i] != 0)
return 1;
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 < sb->u.adfs_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;
for (i = 0; i < sb->u.adfs_sb.s_map_size; i++)
brelse(sb->u.adfs_sb.s_map[i].dm_bh);
kfree(sb->u.adfs_sb.s_map);
}
static int parse_options(struct super_block *sb, char *options)
{
char *value, *opt;
if (!options)
return 0;
for (opt = strtok(options, ","); opt != NULL; opt = strtok(NULL, ",")) {
value = strchr(opt, '=');
if (value)
*value++ = '\0';
if (!strcmp(opt, "uid")) { /* owner of all files */
if (!value || !*value)
return -EINVAL;
sb->u.adfs_sb.s_uid = simple_strtoul(value, &value, 0);
if (*value)
return -EINVAL;
} else
if (!strcmp(opt, "gid")) { /* group owner of all files */
if (!value || !*value)
return -EINVAL;
sb->u.adfs_sb.s_gid = simple_strtoul(value, &value, 0);
if (*value)
return -EINVAL;
} else
if (!strcmp(opt, "ownmask")) { /* owner permission mask */
if (!value || !*value)
return -EINVAL;
sb->u.adfs_sb.s_owner_mask = simple_strtoul(value, &value, 8);
if (*value)
return -EINVAL;
} else
if (!strcmp(opt, "othmask")) { /* others permission mask */
if (!value || !*value)
return -EINVAL;
sb->u.adfs_sb.s_other_mask = simple_strtoul(value, &value, 8);
if (*value)
return -EINVAL;
} else { /* eh? say again. */
printk("ADFS-fs: unrecognised mount option %s\n", opt);
return -EINVAL;
}
}
return 0;
}
static int adfs_remount(struct super_block *sb, int *flags, char *data)
{
return parse_options(sb, data);
}
static int adfs_statfs(struct super_block *sb, struct statfs *buf)
{
struct adfs_sb_info *asb = &sb->u.adfs_sb;
buf->f_type = ADFS_SUPER_MAGIC;
buf->f_namelen = asb->s_namelen;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = asb->s_size;
buf->f_files = asb->s_ids_per_zone * asb->s_map_size;
buf->f_bavail =
buf->f_bfree = adfs_map_free(sb);
buf->f_ffree = buf->f_bfree * buf->f_files / buf->f_blocks;
return 0;
}
static struct super_operations adfs_sops = {
write_inode: adfs_write_inode,
put_super: adfs_put_super,
statfs: adfs_statfs,
remount_fs: adfs_remount,
};
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;
nzones = sb->u.adfs_sb.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, sb->u.adfs_sb.s_map2blk);
sb->u.adfs_sb.s_ids_per_zone = zone_size / (sb->u.adfs_sb.s_idlen + 1);
dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
if (dm == NULL) {
adfs_error(sb, "not enough memory");
return NULL;
}
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 = (dr->disc_size_high << (32 - dr->log2bpmb)) +
(dr->disc_size >> dr->log2bpmb) +
(ADFS_DR_SIZE_BITS - i * zone_size);
if (adfs_checkmap(sb, dm))
return dm;
adfs_error(sb, NULL, "map corrupted");
error_free:
while (--zone >= 0)
brelse(dm[zone].dm_bh);
kfree(dm);
return NULL;
}
static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
{
unsigned long discsize;
discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
return discsize;
}
struct super_block *adfs_read_super(struct super_block *sb, void *data, int silent)
{
struct adfs_discrecord *dr;
struct buffer_head *bh;
struct object_info root_obj;
unsigned char *b_data;
kdev_t dev = sb->s_dev;
/* set default options */
sb->u.adfs_sb.s_uid = 0;
sb->u.adfs_sb.s_gid = 0;
sb->u.adfs_sb.s_owner_mask = S_IRWXU;
sb->u.adfs_sb.s_other_mask = S_IRWXG | S_IRWXO;
if (parse_options(sb, data))
goto error;
sb->s_blocksize = BLOCK_SIZE;
set_blocksize(dev, BLOCK_SIZE);
if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
adfs_error(sb, "unable to read superblock");
goto error;
}
b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
if (adfs_checkbblk(b_data)) {
if (!silent)
printk("VFS: Can't find an adfs filesystem on dev "
"%s.\n", bdevname(dev));
goto error_free_bh;
}
dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
/*
* Do some sanity checks on the ADFS disc record
*/
if (adfs_checkdiscrecord(dr)) {
if (!silent)
printk("VPS: Can't find an adfs filesystem on dev "
"%s.\n", bdevname(dev));
goto error_free_bh;
}
sb->s_blocksize_bits = dr->log2secsize;
sb->s_blocksize = 1 << sb->s_blocksize_bits;
if (sb->s_blocksize != BLOCK_SIZE &&
(sb->s_blocksize == 512 || sb->s_blocksize == 1024 ||
sb->s_blocksize == 2048 || sb->s_blocksize == 4096)) {
brelse(bh);
set_blocksize(dev, sb->s_blocksize);
bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
if (!bh) {
adfs_error(sb, "couldn't read superblock on "
"2nd try.");
goto error;
}
b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
if (adfs_checkbblk(b_data)) {
adfs_error(sb, "disc record mismatch, very weird!");
goto error_free_bh;
}
dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
}
if (sb->s_blocksize != bh->b_size) {
if (!silent)
printk(KERN_ERR "VFS: Unsupported blocksize on dev "
"%s.\n", bdevname(dev));
goto error_free_bh;
}
/*
* blocksize on this device should now be set to the ADFS log2secsize
*/
sb->s_magic = ADFS_SUPER_MAGIC;
sb->u.adfs_sb.s_idlen = dr->idlen;
sb->u.adfs_sb.s_map_size = dr->nzones | (dr->nzones_high << 8);
sb->u.adfs_sb.s_map2blk = dr->log2bpmb - dr->log2secsize;
sb->u.adfs_sb.s_size = adfs_discsize(dr, sb->s_blocksize_bits);
sb->u.adfs_sb.s_version = dr->format_version;
sb->u.adfs_sb.s_log2sharesize = dr->log2sharesize;
sb->u.adfs_sb.s_map = adfs_read_map(sb, dr);
if (!sb->u.adfs_sb.s_map)
goto error_free_bh;
brelse(bh);
/*
* set up enough so that we can read an inode
*/
sb->s_op = &adfs_sops;
dr = (struct adfs_discrecord *)(sb->u.adfs_sb.s_map[0].dm_bh->b_data + 4);
root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
root_obj.name_len = 0;
root_obj.loadaddr = 0;
root_obj.execaddr = 0;
root_obj.size = ADFS_NEWDIR_SIZE;
root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
/*
* If this is a F+ disk with variable length directories,
* get the root_size from the disc record.
*/
if (sb->u.adfs_sb.s_version) {
root_obj.size = dr->root_size;
sb->u.adfs_sb.s_dir = &adfs_fplus_dir_ops;
sb->u.adfs_sb.s_namelen = ADFS_FPLUS_NAME_LEN;
} else {
sb->u.adfs_sb.s_dir = &adfs_f_dir_ops;
sb->u.adfs_sb.s_namelen = ADFS_F_NAME_LEN;
}
sb->s_root = d_alloc_root(adfs_iget(sb, &root_obj));
if (!sb->s_root) {
int i;
for (i = 0; i < sb->u.adfs_sb.s_map_size; i++)
brelse(sb->u.adfs_sb.s_map[i].dm_bh);
kfree(sb->u.adfs_sb.s_map);
adfs_error(sb, "get root inode failed\n");
goto error;
} else
sb->s_root->d_op = &adfs_dentry_operations;
return sb;
error_free_bh:
brelse(bh);
error:
return NULL;
}
static DECLARE_FSTYPE_DEV(adfs_fs_type, "adfs", adfs_read_super);
static int __init init_adfs_fs(void)
{
return register_filesystem(&adfs_fs_type);
}
static void __exit exit_adfs_fs(void)
{
unregister_filesystem(&adfs_fs_type);
}
EXPORT_NO_SYMBOLS;
module_init(init_adfs_fs)
module_exit(exit_adfs_fs)
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