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/*
* super.c
*
* Copyright (c) 1999 Al Smith
*
* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
*/
#include <linux/module.h>
#include <linux/efs.h>
void efs_read_inode(struct inode *);
void efs_put_super(struct super_block *);
int efs_statfs(struct super_block *, struct statfs *, int);
struct super_block * efs_read_super(struct super_block *, void *, int);
static struct file_system_type efs_fs_type = {
"efs", /* filesystem name */
FS_REQUIRES_DEV, /* fs_flags */
efs_read_super, /* entry function pointer */
NULL /* next */
};
static struct super_operations efs_superblock_operations = {
efs_read_inode, /* read_inode */
NULL, /* write_inode */
NULL, /* put_inode */
NULL, /* delete_inode */
NULL, /* notify_change */
efs_put_super, /* put_super */
NULL, /* write_super */
efs_statfs, /* statfs */
NULL /* remount */
};
int init_module(void) {
return register_filesystem(&efs_fs_type);
}
void cleanup_module(void) {
unregister_filesystem(&efs_fs_type);
}
static long efs_validate_vh(struct volume_header *vh, int slice) {
int i, j;
int32_t sblock = 0;
int type;
char name[VDNAMESIZE+1];
if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
printk("EFS: invalid volume descriptor\n");
return 0;
}
#ifdef DEBUG
printk("EFS: bf: %16s\n", vh->vh_bootfile);
#endif
for(i = 0; i < NVDIR; i++) {
for(j = 0; j < VDNAMESIZE; j++) {
name[j] = vh->vh_vd[i].vd_name[j];
}
name[j] = (char) 0;
#ifdef DEBUG
if (name[0]) {
printk("EFS: vh: 0x%8s block: 0x%08x size: 0x%08x\n",
name,
(int) be32_to_cpu(vh->vh_vd[i].vd_lbn),
(int) be32_to_cpu(vh->vh_vd[i].vd_nbytes));
}
#endif
}
for(i = 0; i < NPARTAB; i++) {
type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
#ifdef DEBUG
printk("EFS: pt: start: %08d size: %08d type: %08d\n",
(int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
(int) be32_to_cpu(vh->vh_pt[i].pt_nblks),
type);
#endif
if (slice == i && (type == 5 || type == 7)) {
sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
} else if (slice == -1 && sblock == 0) {
if (type == 5 || type == 7) {
sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
slice = i;
}
}
}
if (sblock) {
printk("EFS: using slice %d (offset 0x%x)\n", slice, sblock);
} else if (slice != -1) {
printk("EFS: no efs filesystem found on slice %d\n", slice);
}
return(sblock);
}
static int efs_validate_super(struct efs_spb *sb, struct efs *super) {
if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic))) return -1;
sb->fs_magic = be32_to_cpu(super->fs_magic);
sb->total_blocks = be32_to_cpu(super->fs_size);
sb->first_block = be32_to_cpu(super->fs_firstcg);
sb->group_size = be32_to_cpu(super->fs_cgfsize);
sb->inode_blocks = be16_to_cpu(super->fs_cgisize);
sb->total_groups = be16_to_cpu(super->fs_ncg);
return 0;
}
struct super_block *efs_read_super(struct super_block *s, void *d, int verbose) {
int slice = -1;
kdev_t dev = s->s_dev;
struct inode *root_inode;
struct efs_spb *spb;
struct buffer_head *bh;
if (d) {
/* parse mount option */
if (!strncmp(d, "slice=", 6)) {
slice = simple_strtoul(d+6, NULL, 10);
} else if (strcmp(d, "")) {
printk("EFS: invalid mount option\n");
return(NULL);
}
}
MOD_INC_USE_COUNT;
lock_super(s);
/* approx 230 bytes available in this union */
spb = (struct efs_spb *) &(s->u.generic_sbp);
set_blocksize(dev, EFS_BLOCKSIZE);
/* read the vh (volume header) block */
bh = bread(dev, 0, EFS_BLOCKSIZE);
if (!bh) {
printk("EFS: cannot read volume header\n");
goto out_no_fs_ul;
}
spb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data, slice);
brelse(bh);
if(!spb->fs_start) {
printk("EFS: invalid volume descriptor\n");
goto out_no_fs_ul;
}
bh = bread(dev, spb->fs_start + EFS_SUPER, EFS_BLOCKSIZE);
if (!bh) {
printk("EFS: unable to read superblock\n");
goto out_no_fs_ul;
}
if (efs_validate_super(spb, (struct efs *) bh->b_data)) {
printk("EFS: invalid superblock\n");
brelse(bh);
goto out_no_fs_ul;
}
s->s_magic = EFS_SUPER_MAGIC;
s->s_blocksize = EFS_BLOCKSIZE;
s->s_blocksize_bits = EFS_BLOCKSIZE_BITS;
if (!(s->s_flags & MS_RDONLY)) {
#ifdef DEBUG
printk("EFS: forcing read-only: RW access not supported\n");
#endif
s->s_flags |= MS_RDONLY;
}
s->s_op = &efs_superblock_operations;
s->s_dev = dev;
s->s_root = NULL;
root_inode = iget(s, EFS_ROOTINODE);
if (root_inode) {
s->s_root = d_alloc_root(root_inode, NULL);
if (!(s->s_root)) {
iput(root_inode);
}
}
unlock_super(s);
if(!(s->s_root)) {
printk("EFS: not mounted\n");
goto out_no_fs;
}
if(check_disk_change(s->s_dev)) {
printk("EFS: device changed\n");
goto out_no_fs;
}
return(s);
out_no_fs_ul:
unlock_super(s);
out_no_fs:
s->s_dev = 0;
MOD_DEC_USE_COUNT;
return(NULL);
}
void efs_put_super(struct super_block *s) {
s->s_dev = 0;
MOD_DEC_USE_COUNT;
}
int efs_statfs(struct super_block *s, struct statfs *buf, int bufsiz) {
struct statfs tmp;
struct efs_spb *sbp = (struct efs_spb *)&s->u.generic_sbp;
tmp.f_type = EFS_SUPER_MAGIC;
tmp.f_bsize = EFS_BLOCKSIZE;
tmp.f_blocks = sbp->total_blocks;
tmp.f_bfree = 0;
tmp.f_bavail = 0;
tmp.f_files = 0; /* ? */
tmp.f_ffree = 0;
tmp.f_fsid.val[0] = (sbp->fs_magic >> 16) & 0xffff;
tmp.f_fsid.val[1] = sbp->fs_magic & 0xffff;
tmp.f_namelen = EFS_MAXNAMELEN;
return copy_to_user(buf, &tmp, bufsiz) ? -EFAULT : 0;
}
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