// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/adfs/super.c
*
* Copyright (C) 1997-1999 Russell King
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/parser.h>
#include <linux/mount.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/statfs.h>
#include <linux/user_namespace.h>
#include <linux/blkdev.h>
#include "adfs.h"
#include "dir_f.h"
#include "dir_fplus.h"
#define ADFS_SB_FLAGS SB_NOATIME
#define ADFS_DEFAULT_OWNER_MASK S_IRWXU
#define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",
sb->s_id, function ? ": " : "",
function ? function : "", &vaf);
va_end(args);
}
void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);
va_end(args);
}
static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
{
unsigned int max_idlen;
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 (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
return 1;
/*
* Maximum idlen is limited to 16 bits for new directories by
* the three-byte storage of an indirect disc address. For
* big directories, idlen must be no greater than 19 v2 [1.0]
*/
max_idlen = dr->format_version ? 19 : 16;
if (dr->idlen > max_idlen)
return 1;
/* reserved bytes should be zero */
for (i = 0; i < sizeof(dr->unused52); i++)
if (dr->unused52[i] != 0)
return 1;
return 0;
}
static void adfs_put_super(struct super_block *sb)
{
struct adfs_sb_info *asb = ADFS_SB(sb);
adfs_free_map(sb);
kfree_rcu(asb, rcu);
}
static int adfs_show_options(struct seq_file *seq, struct dentry *root)
{
struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
seq_printf(seq, ",othmask=%o", asb->s_other_mask);
if (asb->s_ftsuffix != 0)
seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
return 0;
}
enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
static const match_table_t tokens = {
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_ownmask, "ownmask=%o"},
{Opt_othmask, "othmask=%o"},
{Opt_ftsuffix, "ftsuffix=%u"},
{Opt_err, NULL}
};
static int parse_options(struct super_block *sb, struct adfs_sb_info *asb,
char *options)
{
char *p;
int option;
if (!options)
return 0;
while ((p = strsep(&options, ",")) != NULL) {
substring_t args[MAX_OPT_ARGS];
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_uid:
if (match_int(args, &option))
return -EINVAL;
asb->s_uid = make_kuid(current_user_ns(), option);
if (!uid_valid(asb->s_uid))
return -EINVAL;
break;
case Opt_gid:
if (match_int(args, &option))
return -EINVAL;
asb->s_gid = make_kgid(current_user_ns(), option);
if (!gid_valid(asb->s_gid))
return -EINVAL;
break;
case Opt_ownmask:
if (match_octal(args, &option))
return -EINVAL;
asb->s_owner_mask = option;
break;
case Opt_othmask:
if (match_octal(args, &option))
return -EINVAL;
asb->s_other_mask = option;
break;
case Opt_ftsuffix:
if (match_int(args, &option))
return -EINVAL;
asb->s_ftsuffix = option;
break;
default:
adfs_msg(sb, KERN_ERR,
"unrecognised mount option \"%s\" or missing value",
p);
return -EINVAL;
}
}
return 0;
}
static int adfs_remount(struct super_block *sb, int *flags, char *data)
{
struct adfs_sb_info temp_asb;
int ret;
sync_filesystem(sb);
*flags |= ADFS_SB_FLAGS;
temp_asb = *ADFS_SB(sb);
ret = parse_options(sb, &temp_asb, data);
if (ret == 0)
*ADFS_SB(sb) = temp_asb;
return ret;
}
static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct adfs_sb_info *sbi = ADFS_SB(sb);
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
adfs_map_statfs(sb, buf);
buf->f_type = ADFS_SUPER_MAGIC;
buf->f_namelen = sbi->s_namelen;
buf->f_bsize = sb->s_blocksize;
buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
buf->f_fsid = u64_to_fsid(id);
return 0;
}
static struct kmem_cache *adfs_inode_cachep;
static struct inode *adfs_alloc_inode(struct super_block *sb)
{
struct adfs_inode_info *ei;
ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
return &ei->vfs_inode;
}
static void adfs_free_inode(struct inode *inode)
{
kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
}
static int adfs_drop_inode(struct inode *inode)
{
/* always drop inodes if we are read-only */
return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode);
}
static void init_once(void *foo)
{
struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
inode_init_once(&ei->vfs_inode);
}
static int __init init_inodecache(void)
{
adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
sizeof(struct adfs_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_ACCOUNT),
init_once);
if (adfs_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(adfs_inode_cachep);
}
static const struct super_operations adfs_sops = {
.alloc_inode = adfs_alloc_inode,
.free_inode = adfs_free_inode,
.drop_inode = adfs_drop_inode,
.write_inode = adfs_write_inode,
.put_super = adfs_put_super,
.statfs = adfs_statfs,
.remount_fs = adfs_remount,
.show_options = adfs_show_options,
};
static int adfs_probe(struct super_block *sb, unsigned int offset, int silent,
int (*validate)(struct super_block *sb,
struct buffer_head *bh,
struct adfs_discrecord **bhp))
{
struct adfs_sb_info *asb = ADFS_SB(sb);
struct adfs_discrecord *dr;
struct buffer_head *bh;
unsigned int blocksize = BLOCK_SIZE;
int ret, try;
for (try = 0; try < 2; try++) {
/* try to set the requested block size */
if (sb->s_blocksize != blocksize &&
!sb_set_blocksize(sb, blocksize)) {
if (!silent)
adfs_msg(sb, KERN_ERR,
"error: unsupported blocksize");
return -EINVAL;
}
/* read the buffer */
bh = sb_bread(sb, offset >> sb->s_blocksize_bits);
if (!bh) {
adfs_msg(sb, KERN_ERR,
"error: unable to read block %u, try %d",
offset >> sb->s_blocksize_bits, try);
return -EIO;
}
/* validate it */
ret = validate(sb, bh, &dr);
if (ret) {
brelse(bh);
return ret;
}
/* does the block size match the filesystem block size? */
blocksize = 1 << dr->log2secsize;
if (sb->s_blocksize == blocksize) {
asb->s_map = adfs_read_map(sb, dr);
brelse(bh);
return PTR_ERR_OR_ZERO(asb->s_map);
}
brelse(bh);
}
return -EIO;
}
static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh,
struct adfs_discrecord **drp)
{
struct adfs_discrecord *dr;
unsigned char *b_data;
b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
if (adfs_checkbblk(b_data))
return -EILSEQ;
/* Do some sanity checks on the ADFS disc record */
dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
if (adfs_checkdiscrecord(dr))
return -EILSEQ;
*drp = dr;
return 0;
}
static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh,
struct adfs_discrecord **drp)
{
struct adfs_discrecord *dr;
/* Do some sanity checks on the ADFS disc record */
dr = (struct adfs_discrecord *)(bh->b_data + 4);
if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1)
return -EILSEQ;
*drp = dr;
return 0;
}
static int adfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct adfs_discrecord *dr;
struct object_info root_obj;
struct adfs_sb_info *asb;
struct inode *root;
int ret = -EINVAL;
sb->s_flags |= ADFS_SB_FLAGS;
asb = kzalloc(sizeof(*asb), GFP_KERNEL);
if (!asb)
return -ENOMEM;
sb->s_fs_info = asb;
sb->s_magic = ADFS_SUPER_MAGIC;
sb->s_time_gran = 10000000;
/* set default options */
asb->s_uid = GLOBAL_ROOT_UID;
asb->s_gid = GLOBAL_ROOT_GID;
asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
asb->s_ftsuffix = 0;
if (parse_options(sb, asb, data))
goto error;
/* Try to probe the filesystem boot block */
ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk);
if (ret == -EILSEQ)
ret = adfs_probe(sb, 0, silent, adfs_validate_dr0);
if (ret == -EILSEQ) {
if (!silent)
adfs_msg(sb, KERN_ERR,
"error: can't find an ADFS filesystem on dev %s.",
sb->s_id);
ret = -EINVAL;
}
if (ret)
goto error;
/* set up enough so that we can read an inode */
sb->s_op = &adfs_sops;
dr = adfs_map_discrecord(asb->s_map);
root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root);
root_obj.name_len = 0;
/* Set root object date as 01 Jan 1987 00:00:00 */
root_obj.loadaddr = 0xfff0003f;
root_obj.execaddr = 0xec22c000;
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 (dr->format_version) {
root_obj.size = le32_to_cpu(dr->root_size);
asb->s_dir = &adfs_fplus_dir_ops;
asb->s_namelen = ADFS_FPLUS_NAME_LEN;
} else {
asb->s_dir = &adfs_f_dir_ops;
asb->s_namelen = ADFS_F_NAME_LEN;
}
/*
* ,xyz hex filetype suffix may be added by driver
* to files that have valid RISC OS filetype
*/
if (asb->s_ftsuffix)
asb->s_namelen += 4;
sb->s_d_op = &adfs_dentry_operations;
root = adfs_iget(sb, &root_obj);
sb->s_root = d_make_root(root);
if (!sb->s_root) {
adfs_free_map(sb);
adfs_error(sb, "get root inode failed\n");
ret = -EIO;
goto error;
}
return 0;
error:
sb->s_fs_info = NULL;
kfree(asb);
return ret;
}
static struct dentry *adfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super);
}
static struct file_system_type adfs_fs_type = {
.owner = THIS_MODULE,
.name = "adfs",
.mount = adfs_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("adfs");
static int __init init_adfs_fs(void)
{
int err = init_inodecache();
if (err)
goto out1;
err = register_filesystem(&adfs_fs_type);
if (err)
goto out;
return 0;
out:
destroy_inodecache();
out1:
return err;
}
static void __exit exit_adfs_fs(void)
{
unregister_filesystem(&adfs_fs_type);
destroy_inodecache();
}
module_init(init_adfs_fs)
module_exit(exit_adfs_fs)
MODULE_DESCRIPTION("Acorn Disc Filing System");
MODULE_LICENSE("GPL");
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