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/*
* super.c
*
* Copyright (c) 1999 Al Smith
*
* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/locks.h>
#include <linux/efs_fs.h>
#include <linux/efs_vh.h>
#include <linux/efs_fs_sb.h>
static DECLARE_FSTYPE_DEV(efs_fs_type, "efs", efs_read_super);
static struct super_operations efs_superblock_operations = {
read_inode: efs_read_inode,
statfs: efs_statfs,
};
static int __init init_efs_fs(void) {
printk("EFS: "EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n");
return register_filesystem(&efs_fs_type);
}
static void __exit exit_efs_fs(void) {
unregister_filesystem(&efs_fs_type);
}
EXPORT_NO_SYMBOLS;
module_init(init_efs_fs)
module_exit(exit_efs_fs)
static efs_block_t efs_validate_vh(struct volume_header *vh) {
int i;
unsigned int cs, csum, *ui;
efs_block_t sblock = 0; /* shuts up gcc */
struct pt_types *pt_entry;
int pt_type, slice = -1;
if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
/*
* assume that we're dealing with a partition and allow
* read_super() to try and detect a valid superblock
* on the next block.
*/
return 0;
}
ui = ((unsigned int *) (vh + 1)) - 1;
for(csum = 0; ui >= ((unsigned int *) vh);) {
cs = *ui--;
csum += be32_to_cpu(cs);
}
if (csum) {
printk(KERN_INFO "EFS: SGI disklabel: checksum bad, label corrupted\n");
return 0;
}
#ifdef DEBUG
printk(KERN_DEBUG "EFS: bf: \"%16s\"\n", vh->vh_bootfile);
for(i = 0; i < NVDIR; i++) {
int j;
char name[VDNAMESIZE+1];
for(j = 0; j < VDNAMESIZE; j++) {
name[j] = vh->vh_vd[i].vd_name[j];
}
name[j] = (char) 0;
if (name[0]) {
printk(KERN_DEBUG "EFS: vh: %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++) {
pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) {
if (pt_type == pt_entry->pt_type) break;
}
#ifdef DEBUG
if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) {
printk(KERN_DEBUG "EFS: pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n",
i,
(int) be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
(int) be32_to_cpu(vh->vh_pt[i].pt_nblks),
pt_type,
(pt_entry->pt_name) ? pt_entry->pt_name : "unknown");
}
#endif
if (IS_EFS(pt_type)) {
sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
slice = i;
}
}
if (slice == -1) {
printk(KERN_NOTICE "EFS: partition table contained no EFS partitions\n");
#ifdef DEBUG
} else {
printk(KERN_INFO "EFS: using slice %d (type %s, offset 0x%x)\n",
slice,
(pt_entry->pt_name) ? pt_entry->pt_name : "unknown",
sblock);
#endif
}
return(sblock);
}
static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *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->data_free = be32_to_cpu(super->fs_tfree);
sb->inode_free = be32_to_cpu(super->fs_tinode);
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 silent) {
kdev_t dev = s->s_dev;
struct efs_sb_info *sb;
struct buffer_head *bh;
sb = SUPER_INFO(s);
set_blocksize(dev, EFS_BLOCKSIZE);
/* read the vh (volume header) block */
bh = bread(dev, 0, EFS_BLOCKSIZE);
if (!bh) {
printk(KERN_ERR "EFS: cannot read volume header\n");
goto out_no_fs_ul;
}
/*
* if this returns zero then we didn't find any partition table.
* this isn't (yet) an error - just assume for the moment that
* the device is valid and go on to search for a superblock.
*/
sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data);
brelse(bh);
if (sb->fs_start == -1) {
goto out_no_fs_ul;
}
bh = bread(dev, sb->fs_start + EFS_SUPER, EFS_BLOCKSIZE);
if (!bh) {
printk(KERN_ERR "EFS: cannot read superblock\n");
goto out_no_fs_ul;
}
if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {
#ifdef DEBUG
printk(KERN_WARNING "EFS: invalid superblock at block %u\n", sb->fs_start + EFS_SUPER);
#endif
brelse(bh);
goto out_no_fs_ul;
}
brelse(bh);
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(KERN_INFO "EFS: forcing read-only mode\n");
#endif
s->s_flags |= MS_RDONLY;
}
s->s_op = &efs_superblock_operations;
s->s_dev = dev;
s->s_root = d_alloc_root(iget(s, EFS_ROOTINODE));
if (!(s->s_root)) {
printk(KERN_ERR "EFS: get root inode failed\n");
goto out_no_fs;
}
if (check_disk_change(s->s_dev)) {
printk(KERN_ERR "EFS: device changed\n");
goto out_no_fs;
}
return(s);
out_no_fs_ul:
out_no_fs:
return(NULL);
}
int efs_statfs(struct super_block *s, struct statfs *buf) {
struct efs_sb_info *sb = SUPER_INFO(s);
buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */
buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */
buf->f_blocks = sb->total_groups * /* total data blocks */
(sb->group_size - sb->inode_blocks);
buf->f_bfree = sb->data_free; /* free data blocks */
buf->f_bavail = sb->data_free; /* free blocks for non-root */
buf->f_files = sb->total_groups * /* total inodes */
sb->inode_blocks *
(EFS_BLOCKSIZE / sizeof(struct efs_dinode));
buf->f_ffree = sb->inode_free; /* free inodes */
buf->f_fsid.val[0] = (sb->fs_magic >> 16) & 0xffff; /* fs ID */
buf->f_fsid.val[1] = sb->fs_magic & 0xffff; /* fs ID */
buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */
return 0;
}
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