/* * 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); 	s->s_magic		= EFS_SUPER_MAGIC;	s->s_blocksize		= EFS_BLOCKSIZE;	s->s_blocksize_bits	= EFS_BLOCKSIZE_BITS;	set_blocksize(dev, EFS_BLOCKSIZE);  	/* read the vh (volume header) block */	bh = sb_bread(s, 0);	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 = sb_bread(s, sb->fs_start + EFS_SUPER);	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);	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_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;	}	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;}