inode.c

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	if (!buffer_uptodate(bh)) {
		ll_rw_block(READ, 1, &bh);
		wait_on_buffer(bh);
		if (!buffer_uptodate(bh)) {
			brelse(bh);
			return NULL;
		}
	}
	p = nr + (unsigned short *) bh->b_data;
repeat:
	tmp = *p;
	if (tmp) {
		result = getblk(bh->b_dev, tmp, BLOCK_SIZE);
		if (tmp == *p) {
			brelse(bh);
			return result;
		}
		brelse(result);
		goto repeat;
	}
	if (!create) {
		brelse(bh);
		return NULL;
	}
	tmp = minix_new_block(inode->i_sb);
	if (!tmp) {
		brelse(bh);
		return NULL;
	}
	result = getblk(bh->b_dev, tmp, BLOCK_SIZE);
	if (*p) {
		minix_free_block(inode->i_sb,tmp);
		brelse(result);
		goto repeat;
	}
	*p = tmp;
	mark_buffer_dirty(bh, 1);
	brelse(bh);
	return result;
}

static struct buffer_head * V1_minix_getblk(struct inode * inode, int block, 
					    int create)
{
	struct buffer_head * bh;

	if (block<0) {
		printk("minix_getblk: block<0");
		return NULL;
	}
	if (block >= inode->i_sb->u.minix_sb.s_max_size/BLOCK_SIZE) {
		printk("minix_getblk: block>big");
		return NULL;
	}
	if (block < 7)
		return V1_inode_getblk(inode,block,create);
	block -= 7;
	if (block < 512) {
		bh = V1_inode_getblk(inode,7,create);
		return V1_block_getblk(inode, bh, block, create);
	}
	block -= 512;
	bh = V1_inode_getblk(inode,8,create);
	bh = V1_block_getblk(inode, bh, (block>>9) & 511, create);
	return V1_block_getblk(inode, bh, block & 511, create);
}

/*
 * The minix V2 fs getblk functions.
 */
static struct buffer_head * V2_inode_getblk(struct inode * inode, int nr, 
					    int create)
{
	int tmp;
	unsigned long *p;
	struct buffer_head * result;

	p = (unsigned long *) inode->u.minix_i.u.i2_data + nr;
repeat:
	tmp = *p;
	if (tmp) {
		result = getblk(inode->i_dev, tmp, BLOCK_SIZE);
		if (tmp == *p)
			return result;
		brelse(result);
		goto repeat;
	}
	if (!create)
		return NULL;
	tmp = minix_new_block(inode->i_sb);
	if (!tmp)
		return NULL;
	result = getblk(inode->i_dev, tmp, BLOCK_SIZE);
	if (*p) {
		minix_free_block(inode->i_sb,tmp);
		brelse(result);
		goto repeat;
	}
	*p = tmp;
	inode->i_ctime = CURRENT_TIME;
	inode->i_dirt = 1;
	return result;
}

static struct buffer_head * V2_block_getblk(struct inode * inode, 
	struct buffer_head * bh, int nr, int create)
{
	int tmp;
	unsigned long *p;
	struct buffer_head * result;

	if (!bh)
		return NULL;
	if (!buffer_uptodate(bh)) {
		ll_rw_block(READ, 1, &bh);
		wait_on_buffer(bh);
		if (!buffer_uptodate(bh)) {
			brelse(bh);
			return NULL;
		}
	}
	p = nr + (unsigned long *) bh->b_data;
repeat:
	tmp = *p;
	if (tmp) {
		result = getblk(bh->b_dev, tmp, BLOCK_SIZE);
		if (tmp == *p) {
			brelse(bh);
			return result;
		}
		brelse(result);
		goto repeat;
	}
	if (!create) {
		brelse(bh);
		return NULL;
	}
	tmp = minix_new_block(inode->i_sb);
	if (!tmp) {
		brelse(bh);
		return NULL;
	}
	result = getblk(bh->b_dev, tmp, BLOCK_SIZE);
	if (*p) {
		minix_free_block(inode->i_sb,tmp);
		brelse(result);
		goto repeat;
	}
	*p = tmp;
	mark_buffer_dirty(bh, 1);
	brelse(bh);
	return result;
}

static struct buffer_head * V2_minix_getblk(struct inode * inode, int block, 
					    int create)
{
	struct buffer_head * bh;

	if (block<0) {
		printk("minix_getblk: block<0");
		return NULL;
	}
	if (block >= inode->i_sb->u.minix_sb.s_max_size/BLOCK_SIZE) {
		printk("minix_getblk: block>big");
		return NULL;
	}
	if (block < 7)
		return V2_inode_getblk(inode,block,create);
	block -= 7;
	if (block < 256) {
		bh = V2_inode_getblk(inode,7,create);
		return V2_block_getblk(inode, bh, block, create);
	}
	block -= 256;
	if (block < 256*256) {
		bh = V2_inode_getblk(inode,8,create);
		bh = V2_block_getblk(inode, bh, (block>>8) & 255, create);
		return V2_block_getblk(inode, bh, block & 255, create);
	}
	block -= 256*256;
	bh = V2_inode_getblk(inode,9,create);
	bh = V2_block_getblk(inode, bh, (block >> 16) & 255, create);
	bh = V2_block_getblk(inode, bh, (block >> 8) & 255, create);
	return V2_block_getblk(inode, bh, block & 255, create);
}

/*
 * the global minix fs getblk function.
 */
struct buffer_head * minix_getblk(struct inode * inode, int block, int create)
{
	if (INODE_VERSION(inode) == MINIX_V1)
		return V1_minix_getblk(inode,block,create);
	else
		return V2_minix_getblk(inode,block,create);
}

struct buffer_head * minix_bread(struct inode * inode, int block, int create)
{
	struct buffer_head * bh;

	bh = minix_getblk(inode,block,create);
	if (!bh || buffer_uptodate(bh))
		return bh;
	ll_rw_block(READ, 1, &bh);
	wait_on_buffer(bh);
	if (buffer_uptodate(bh))
		return bh;
	brelse(bh);
	return NULL;
}

/*
 * The minix V1 function to read an inode.
 */
static void V1_minix_read_inode(struct inode * inode)
{
	struct buffer_head * bh;
	struct minix_inode * raw_inode;
	int block, ino;

	ino = inode->i_ino;
	inode->i_op = NULL;
	inode->i_mode = 0;
	if (!ino || ino >= inode->i_sb->u.minix_sb.s_ninodes) {
		printk("Bad inode number on dev %s"
		       ": %d is out of range\n",
			kdevname(inode->i_dev), ino);
		return;
	}
	block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks +
		    inode->i_sb->u.minix_sb.s_zmap_blocks +
		    (ino-1)/MINIX_INODES_PER_BLOCK;
	if (!(bh=bread(inode->i_dev,block, BLOCK_SIZE))) {
		printk("Major problem: unable to read inode from dev "
		       "%s\n", kdevname(inode->i_dev));
		return;
	}
	raw_inode = ((struct minix_inode *) bh->b_data) +
		    (ino-1)%MINIX_INODES_PER_BLOCK;
	inode->i_mode = raw_inode->i_mode;
	inode->i_uid = raw_inode->i_uid;
	inode->i_gid = raw_inode->i_gid;
	inode->i_nlink = raw_inode->i_nlinks;
	inode->i_size = raw_inode->i_size;
	inode->i_mtime = inode->i_atime = inode->i_ctime = raw_inode->i_time;
	inode->i_blocks = inode->i_blksize = 0;
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		inode->i_rdev = to_kdev_t(raw_inode->i_zone[0]);
	else for (block = 0; block < 9; block++)
		inode->u.minix_i.u.i1_data[block] = raw_inode->i_zone[block];
	brelse(bh);
	if (S_ISREG(inode->i_mode))
		inode->i_op = &minix_file_inode_operations;
	else if (S_ISDIR(inode->i_mode))
		inode->i_op = &minix_dir_inode_operations;
	else if (S_ISLNK(inode->i_mode))
		inode->i_op = &minix_symlink_inode_operations;
	else if (S_ISCHR(inode->i_mode))
		inode->i_op = &chrdev_inode_operations;
	else if (S_ISBLK(inode->i_mode))
		inode->i_op = &blkdev_inode_operations;
	else if (S_ISFIFO(inode->i_mode))
		init_fifo(inode);
}

/*
 * The minix V2 function to read an inode.
 */
static void V2_minix_read_inode(struct inode * inode)
{
	struct buffer_head * bh;
	struct minix2_inode * raw_inode;
	int block, ino;

	ino = inode->i_ino;
	inode->i_op = NULL;
	inode->i_mode = 0;
	if (!ino || ino >= inode->i_sb->u.minix_sb.s_ninodes) {
		printk("Bad inode number on dev %s"
		       ": %d is out of range\n",
			kdevname(inode->i_dev), ino);
		return;
	}
	block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks +
		    inode->i_sb->u.minix_sb.s_zmap_blocks +
		    (ino-1)/MINIX2_INODES_PER_BLOCK;
	if (!(bh=bread(inode->i_dev,block, BLOCK_SIZE))) {
		printk("Major problem: unable to read inode from dev "
		       "%s\n", kdevname(inode->i_dev));
		return;
	}
	raw_inode = ((struct minix2_inode *) bh->b_data) +
		    (ino-1)%MINIX2_INODES_PER_BLOCK;
	inode->i_mode = raw_inode->i_mode;
	inode->i_uid = raw_inode->i_uid;
	inode->i_gid = raw_inode->i_gid;
	inode->i_nlink = raw_inode->i_nlinks;
	inode->i_size = raw_inode->i_size;
	inode->i_mtime = raw_inode->i_mtime;
	inode->i_atime = raw_inode->i_atime;
	inode->i_ctime = raw_inode->i_ctime;
	inode->i_blocks = inode->i_blksize = 0;
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		inode->i_rdev = to_kdev_t(raw_inode->i_zone[0]);
	else for (block = 0; block < 10; block++)
		inode->u.minix_i.u.i2_data[block] = raw_inode->i_zone[block];
	brelse(bh);
	if (S_ISREG(inode->i_mode))
		inode->i_op = &minix_file_inode_operations;
	else if (S_ISDIR(inode->i_mode))
		inode->i_op = &minix_dir_inode_operations;
	else if (S_ISLNK(inode->i_mode))
		inode->i_op = &minix_symlink_inode_operations;
	else if (S_ISCHR(inode->i_mode))
		inode->i_op = &chrdev_inode_operations;
	else if (S_ISBLK(inode->i_mode))
		inode->i_op = &blkdev_inode_operations;
	else if (S_ISFIFO(inode->i_mode))
		init_fifo(inode);
}

/*
 * The global function to read an inode.
 */
void minix_read_inode(struct inode * inode)
{
	if (INODE_VERSION(inode) == MINIX_V1)
		V1_minix_read_inode(inode);
	else
		V2_minix_read_inode(inode);
}

/*
 * The minix V1 function to synchronize an inode.
 */
static struct buffer_head * V1_minix_update_inode(struct inode * inode)
{
	struct buffer_head * bh;
	struct minix_inode * raw_inode;
	int ino, block;

	ino = inode->i_ino;
	if (!ino || ino >= inode->i_sb->u.minix_sb.s_ninodes) {
		printk("Bad inode number on dev %s"
		       ": %d is out of range\n",
			kdevname(inode->i_dev), ino);
		inode->i_dirt = 0;
		return 0;
	}
	block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks + inode->i_sb->u.minix_sb.s_zmap_blocks +
		(ino-1)/MINIX_INODES_PER_BLOCK;
	if (!(bh=bread(inode->i_dev, block, BLOCK_SIZE))) {
		printk("unable to read i-node block\n");
		inode->i_dirt = 0;
		return 0;
	}
	raw_inode = ((struct minix_inode *)bh->b_data) +
		(ino-1)%MINIX_INODES_PER_BLOCK;
	raw_inode->i_mode = inode->i_mode;
	raw_inode->i_uid = inode->i_uid;
	raw_inode->i_gid = inode->i_gid;
	raw_inode->i_nlinks = inode->i_nlink;
	raw_inode->i_size = inode->i_size;
	raw_inode->i_time = inode->i_mtime;
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		raw_inode->i_zone[0] = kdev_t_to_nr(inode->i_rdev);
	else for (block = 0; block < 9; block++)
		raw_inode->i_zone[block] = inode->u.minix_i.u.i1_data[block];
	inode->i_dirt=0;
	mark_buffer_dirty(bh, 1);
	return bh;
}

/*
 * The minix V2 function to synchronize an inode.
 */
static struct buffer_head * V2_minix_update_inode(struct inode * inode)
{
	struct buffer_head * bh;
	struct minix2_inode * raw_inode;
	int ino, block;

	ino = inode->i_ino;
	if (!ino || ino >= inode->i_sb->u.minix_sb.s_ninodes) {
		printk("Bad inode number on dev %s"
		       ": %d is out of range\n",
			kdevname(inode->i_dev), ino);
		inode->i_dirt = 0;
		return 0;
	}
	block = 2 + inode->i_sb->u.minix_sb.s_imap_blocks + inode->i_sb->u.minix_sb.s_zmap_blocks +
		(ino-1)/MINIX2_INODES_PER_BLOCK;
	if (!(bh=bread(inode->i_dev, block, BLOCK_SIZE))) {
		printk("unable to read i-node block\n");
		inode->i_dirt = 0;
		return 0;
	}
	raw_inode = ((struct minix2_inode *)bh->b_data) +
		(ino-1)%MINIX2_INODES_PER_BLOCK;
	raw_inode->i_mode = inode->i_mode;
	raw_inode->i_uid = inode->i_uid;
	raw_inode->i_gid = inode->i_gid;
	raw_inode->i_nlinks = inode->i_nlink;
	raw_inode->i_size = inode->i_size;
	raw_inode->i_mtime = inode->i_mtime;
	raw_inode->i_atime = inode->i_atime;
	raw_inode->i_ctime = inode->i_ctime;
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		raw_inode->i_zone[0] = kdev_t_to_nr(inode->i_rdev);
	else for (block = 0; block < 10; block++)
		raw_inode->i_zone[block] = inode->u.minix_i.u.i2_data[block];
	inode->i_dirt=0;
	mark_buffer_dirty(bh, 1);
	return bh;
}

struct buffer_head *minix_update_inode(struct inode *inode)
{
	if (INODE_VERSION(inode) == MINIX_V1)
		return V1_minix_update_inode(inode);
	else
		return V2_minix_update_inode(inode);
}

void minix_write_inode(struct inode * inode)
{
	struct buffer_head *bh;

	bh = minix_update_inode(inode);
	brelse(bh);
}

int minix_sync_inode(struct inode * inode)
{
	int err = 0;
	struct buffer_head *bh;

	bh = minix_update_inode(inode);
	if (bh && buffer_dirty(bh))
	{
		ll_rw_block(WRITE, 1, &bh);
		wait_on_buffer(bh);
		if (buffer_req(bh) && !buffer_uptodate(bh))
		{
			printk ("IO error syncing minix inode ["
				"%s:%08lx]\n",
				kdevname(inode->i_dev), inode->i_ino);
			err = -1;
		}
	}
	else if (!bh)
		err = -1;
	brelse (bh);
	return err;
}

static struct file_system_type minix_fs_type = {
	minix_read_super, "minix", 1, NULL
};

int init_minix_fs(void)
{
        return register_filesystem(&minix_fs_type);
}

#ifdef MODULE
int init_module(void)
{
	int status;

	if ((status = init_minix_fs()) == 0)
		register_symtab(0);
	return status;
}

void cleanup_module(void)
{
	unregister_filesystem(&minix_fs_type);
}

#endif