[net-next-2.6.git] / fs / hppfs / hppfs_kern.c

/*
 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
 * Licensed under the GPL
 */

#include <linux/fs.h>
#include <linux/file.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/dcache.h>
#include <linux/statfs.h>
#include <asm/uaccess.h>
#include <asm/fcntl.h>
#include "os.h"

static int init_inode(struct inode *inode, struct dentry *dentry);

struct hppfs_data {
	struct list_head list;
	char contents[PAGE_SIZE - sizeof(struct list_head)];
};

struct hppfs_private {
	struct file *proc_file;
	int host_fd;
	loff_t len;
	struct hppfs_data *contents;
};

struct hppfs_inode_info {
        struct dentry *proc_dentry;
	struct inode vfs_inode;
};

static inline struct hppfs_inode_info *HPPFS_I(struct inode *inode)
{
	return container_of(inode, struct hppfs_inode_info, vfs_inode);
}

#define HPPFS_SUPER_MAGIC 0xb00000ee

static struct super_operations hppfs_sbops;

static int is_pid(struct dentry *dentry)
{
	struct super_block *sb;
	int i;

	sb = dentry->d_sb;
	if((sb->s_op != &hppfs_sbops) || (dentry->d_parent != sb->s_root))
		return(0);

	for(i = 0; i < dentry->d_name.len; i++){
		if(!isdigit(dentry->d_name.name[i]))
			return(0);
	}
	return(1);
}

static char *dentry_name(struct dentry *dentry, int extra)
{
	struct dentry *parent;
	char *root, *name;
	const char *seg_name;
	int len, seg_len;

	len = 0;
	parent = dentry;
	while(parent->d_parent != parent){
		if(is_pid(parent))
			len += strlen("pid") + 1;
		else len += parent->d_name.len + 1;
		parent = parent->d_parent;
	}

	root = "proc";
	len += strlen(root);
	name = kmalloc(len + extra + 1, GFP_KERNEL);
	if(name == NULL) return(NULL);

	name[len] = '\0';
	parent = dentry;
	while(parent->d_parent != parent){
		if(is_pid(parent)){
			seg_name = "pid";
			seg_len = strlen("pid");
		}
		else {
			seg_name = parent->d_name.name;
			seg_len = parent->d_name.len;
		}

		len -= seg_len + 1;
		name[len] = '/';
		strncpy(&name[len + 1], seg_name, seg_len);
		parent = parent->d_parent;
	}
	strncpy(name, root, strlen(root));
	return(name);
}

struct dentry_operations hppfs_dentry_ops = {
};

static int file_removed(struct dentry *dentry, const char *file)
{
	char *host_file;
	int extra, fd;

	extra = 0;
	if(file != NULL) extra += strlen(file) + 1;

	host_file = dentry_name(dentry, extra + strlen("/remove"));
	if(host_file == NULL){
		printk("file_removed : allocation failed\n");
		return(-ENOMEM);
	}

	if(file != NULL){
		strcat(host_file, "/");
		strcat(host_file, file);
	}
	strcat(host_file, "/remove");

	fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
	kfree(host_file);
	if(fd > 0){
		os_close_file(fd);
		return(1);
	}
	return(0);
}

static void hppfs_read_inode(struct inode *ino)
{
	struct inode *proc_ino;

	if(HPPFS_I(ino)->proc_dentry == NULL)
		return;

	proc_ino = HPPFS_I(ino)->proc_dentry->d_inode;
	ino->i_uid = proc_ino->i_uid;
	ino->i_gid = proc_ino->i_gid;
	ino->i_atime = proc_ino->i_atime;
	ino->i_mtime = proc_ino->i_mtime;
	ino->i_ctime = proc_ino->i_ctime;
	ino->i_ino = proc_ino->i_ino;
	ino->i_mode = proc_ino->i_mode;
	ino->i_nlink = proc_ino->i_nlink;
	ino->i_size = proc_ino->i_size;
	ino->i_blksize = proc_ino->i_blksize;
	ino->i_blocks = proc_ino->i_blocks;
}

static struct dentry *hppfs_lookup(struct inode *ino, struct dentry *dentry,
                                  struct nameidata *nd)
{
	struct dentry *proc_dentry, *new, *parent;
	struct inode *inode;
	int err, deleted;

	deleted = file_removed(dentry, NULL);
	if(deleted < 0)
		return(ERR_PTR(deleted));
	else if(deleted)
		return(ERR_PTR(-ENOENT));

	err = -ENOMEM;
	parent = HPPFS_I(ino)->proc_dentry;
	mutex_lock(&parent->d_inode->i_mutex);
	proc_dentry = d_lookup(parent, &dentry->d_name);
	if(proc_dentry == NULL){
		proc_dentry = d_alloc(parent, &dentry->d_name);
		if(proc_dentry == NULL){
			mutex_unlock(&parent->d_inode->i_mutex);
			goto out;
		}
		new = (*parent->d_inode->i_op->lookup)(parent->d_inode,
						       proc_dentry, NULL);
		if(new){
			dput(proc_dentry);
			proc_dentry = new;
		}
	}
	mutex_unlock(&parent->d_inode->i_mutex);

	if(IS_ERR(proc_dentry))
		return(proc_dentry);

	inode = iget(ino->i_sb, 0);
	if(inode == NULL)
		goto out_dput;

	err = init_inode(inode, proc_dentry);
	if(err)
		goto out_put;

	hppfs_read_inode(inode);

 	d_add(dentry, inode);
	dentry->d_op = &hppfs_dentry_ops;
	return(NULL);

 out_put:
	iput(inode);
 out_dput:
	dput(proc_dentry);
 out:
	return(ERR_PTR(err));
}

static struct inode_operations hppfs_file_iops = {
};

static ssize_t read_proc(struct file *file, char *buf, ssize_t count,
			 loff_t *ppos, int is_user)
{
	ssize_t (*read)(struct file *, char *, size_t, loff_t *);
	ssize_t n;

	read = file->f_dentry->d_inode->i_fop->read;

	if(!is_user)
		set_fs(KERNEL_DS);

	n = (*read)(file, buf, count, &file->f_pos);

	if(!is_user)
		set_fs(USER_DS);

	if(ppos) *ppos = file->f_pos;
	return n;
}

static ssize_t hppfs_read_file(int fd, char *buf, ssize_t count)
{
	ssize_t n;
	int cur, err;
	char *new_buf;

	n = -ENOMEM;
	new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if(new_buf == NULL){
		printk("hppfs_read_file : kmalloc failed\n");
		goto out;
	}
	n = 0;
	while(count > 0){
		cur = min_t(ssize_t, count, PAGE_SIZE);
		err = os_read_file(fd, new_buf, cur);
		if(err < 0){
			printk("hppfs_read : read failed, errno = %d\n",
			       err);
			n = err;
			goto out_free;
		}
		else if(err == 0)
			break;

		if(copy_to_user(buf, new_buf, err)){
			n = -EFAULT;
			goto out_free;
		}
		n += err;
		count -= err;
	}
 out_free:
	kfree(new_buf);
 out:
	return n;
}

static ssize_t hppfs_read(struct file *file, char *buf, size_t count,
			  loff_t *ppos)
{
	struct hppfs_private *hppfs = file->private_data;
	struct hppfs_data *data;
	loff_t off;
	int err;

	if(hppfs->contents != NULL){
		if(*ppos >= hppfs->len) return(0);

		data = hppfs->contents;
		off = *ppos;
		while(off >= sizeof(data->contents)){
			data = list_entry(data->list.next, struct hppfs_data,
					  list);
			off -= sizeof(data->contents);
		}

		if(off + count > hppfs->len)
			count = hppfs->len - off;
		copy_to_user(buf, &data->contents[off], count);
		*ppos += count;
	}
	else if(hppfs->host_fd != -1){
		err = os_seek_file(hppfs->host_fd, *ppos);
		if(err){
			printk("hppfs_read : seek failed, errno = %d\n", err);
			return(err);
		}
		count = hppfs_read_file(hppfs->host_fd, buf, count);
		if(count > 0)
			*ppos += count;
	}
	else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);

	return(count);
}

static ssize_t hppfs_write(struct file *file, const char *buf, size_t len,
			   loff_t *ppos)
{
	struct hppfs_private *data = file->private_data;
	struct file *proc_file = data->proc_file;
	ssize_t (*write)(struct file *, const char *, size_t, loff_t *);
	int err;

	write = proc_file->f_dentry->d_inode->i_fop->write;

	proc_file->f_pos = file->f_pos;
	err = (*write)(proc_file, buf, len, &proc_file->f_pos);
	file->f_pos = proc_file->f_pos;

	return(err);
}

static int open_host_sock(char *host_file, int *filter_out)
{
	char *end;
	int fd;

	end = &host_file[strlen(host_file)];
	strcpy(end, "/rw");
	*filter_out = 1;
	fd = os_connect_socket(host_file);
	if(fd > 0)
		return(fd);

	strcpy(end, "/r");
	*filter_out = 0;
	fd = os_connect_socket(host_file);
	return(fd);
}

static void free_contents(struct hppfs_data *head)
{
	struct hppfs_data *data;
	struct list_head *ele, *next;

	if(head == NULL) return;

	list_for_each_safe(ele, next, &head->list){
		data = list_entry(ele, struct hppfs_data, list);
		kfree(data);
	}
	kfree(head);
}

static struct hppfs_data *hppfs_get_data(int fd, int filter,
					 struct file *proc_file,
					 struct file *hppfs_file,
					 loff_t *size_out)
{
	struct hppfs_data *data, *new, *head;
	int n, err;

	err = -ENOMEM;
	data = kmalloc(sizeof(*data), GFP_KERNEL);
	if(data == NULL){
		printk("hppfs_get_data : head allocation failed\n");
		goto failed;
	}

	INIT_LIST_HEAD(&data->list);

	head = data;
	*size_out = 0;

	if(filter){
		while((n = read_proc(proc_file, data->contents,
				     sizeof(data->contents), NULL, 0)) > 0)
			os_write_file(fd, data->contents, n);
		err = os_shutdown_socket(fd, 0, 1);
		if(err){
			printk("hppfs_get_data : failed to shut down "
			       "socket\n");
			goto failed_free;
		}
	}
	while(1){
		n = os_read_file(fd, data->contents, sizeof(data->contents));
		if(n < 0){
			err = n;
			printk("hppfs_get_data : read failed, errno = %d\n",
			       err);
			goto failed_free;
		}
		else if(n == 0)
			break;

		*size_out += n;

		if(n < sizeof(data->contents))
			break;

		new = kmalloc(sizeof(*data), GFP_KERNEL);
		if(new == 0){
			printk("hppfs_get_data : data allocation failed\n");
			err = -ENOMEM;
			goto failed_free;
		}

		INIT_LIST_HEAD(&new->list);
		list_add(&new->list, &data->list);
		data = new;
	}
	return(head);

 failed_free:
	free_contents(head);
 failed:
	return(ERR_PTR(err));
}

static struct hppfs_private *hppfs_data(void)
{
	struct hppfs_private *data;

	data = kmalloc(sizeof(*data), GFP_KERNEL);
	if(data == NULL)
		return(data);

	*data = ((struct hppfs_private ) { .host_fd  		= -1,
					   .len  		= -1,
					   .contents 		= NULL } );
	return(data);
}

static int file_mode(int fmode)
{
	if(fmode == (FMODE_READ | FMODE_WRITE))
		return(O_RDWR);
	if(fmode == FMODE_READ)
		return(O_RDONLY);
	if(fmode == FMODE_WRITE)
		return(O_WRONLY);
	return(0);
}

static int hppfs_open(struct inode *inode, struct file *file)
{
	struct hppfs_private *data;
	struct dentry *proc_dentry;
	char *host_file;
	int err, fd, type, filter;

	err = -ENOMEM;
	data = hppfs_data();
	if(data == NULL)
		goto out;

	host_file = dentry_name(file->f_dentry, strlen("/rw"));
	if(host_file == NULL)
		goto out_free2;

	proc_dentry = HPPFS_I(inode)->proc_dentry;

	/* XXX This isn't closed anywhere */
	data->proc_file = dentry_open(dget(proc_dentry), NULL,
				      file_mode(file->f_mode));
	err = PTR_ERR(data->proc_file);
	if(IS_ERR(data->proc_file))
		goto out_free1;

	type = os_file_type(host_file);
	if(type == OS_TYPE_FILE){
		fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
		if(fd >= 0)
			data->host_fd = fd;
		else printk("hppfs_open : failed to open '%s', errno = %d\n",
			    host_file, -fd);

		data->contents = NULL;
	}
	else if(type == OS_TYPE_DIR){
		fd = open_host_sock(host_file, &filter);
		if(fd > 0){
			data->contents = hppfs_get_data(fd, filter,
							data->proc_file,
							file, &data->len);
			if(!IS_ERR(data->contents))
				data->host_fd = fd;
		}
		else printk("hppfs_open : failed to open a socket in "
			    "'%s', errno = %d\n", host_file, -fd);
	}
	kfree(host_file);

	file->private_data = data;
	return(0);

 out_free1:
	kfree(host_file);
 out_free2:
	free_contents(data->contents);
	kfree(data);
 out:
	return(err);
}

static int hppfs_dir_open(struct inode *inode, struct file *file)
{
	struct hppfs_private *data;
	struct dentry *proc_dentry;
	int err;

	err = -ENOMEM;
	data = hppfs_data();
	if(data == NULL)
		goto out;

	proc_dentry = HPPFS_I(inode)->proc_dentry;
	data->proc_file = dentry_open(dget(proc_dentry), NULL,
				      file_mode(file->f_mode));
	err = PTR_ERR(data->proc_file);
	if(IS_ERR(data->proc_file))
		goto out_free;

	file->private_data = data;
	return(0);

 out_free:
	kfree(data);
 out:
	return(err);
}

static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
{
	struct hppfs_private *data = file->private_data;
	struct file *proc_file = data->proc_file;
	loff_t (*llseek)(struct file *, loff_t, int);
	loff_t ret;

	llseek = proc_file->f_dentry->d_inode->i_fop->llseek;
	if(llseek != NULL){
		ret = (*llseek)(proc_file, off, where);
		if(ret < 0)
			return(ret);
	}

	return(default_llseek(file, off, where));
}

static struct file_operations hppfs_file_fops = {
	.owner		= NULL,
	.llseek		= hppfs_llseek,
	.read		= hppfs_read,
	.write		= hppfs_write,
	.open		= hppfs_open,
};

struct hppfs_dirent {
	void *vfs_dirent;
	filldir_t filldir;
	struct dentry *dentry;
};

static int hppfs_filldir(void *d, const char *name, int size,
			 loff_t offset, ino_t inode, unsigned int type)
{
	struct hppfs_dirent *dirent = d;

	if(file_removed(dirent->dentry, name))
		return(0);

	return((*dirent->filldir)(dirent->vfs_dirent, name, size, offset,
				  inode, type));
}

static int hppfs_readdir(struct file *file, void *ent, filldir_t filldir)
{
	struct hppfs_private *data = file->private_data;
	struct file *proc_file = data->proc_file;
	int (*readdir)(struct file *, void *, filldir_t);
	struct hppfs_dirent dirent = ((struct hppfs_dirent)
		                      { .vfs_dirent  	= ent,
					.filldir 	= filldir,
					.dentry  	= file->f_dentry } );
	int err;

	readdir = proc_file->f_dentry->d_inode->i_fop->readdir;

	proc_file->f_pos = file->f_pos;
	err = (*readdir)(proc_file, &dirent, hppfs_filldir);
	file->f_pos = proc_file->f_pos;

	return(err);
}

static int hppfs_fsync(struct file *file, struct dentry *dentry, int datasync)
{
	return(0);
}

static struct file_operations hppfs_dir_fops = {
	.owner		= NULL,
	.readdir	= hppfs_readdir,
	.open		= hppfs_dir_open,
	.fsync		= hppfs_fsync,
};

static int hppfs_statfs(struct super_block *sb, struct kstatfs *sf)
{
	sf->f_blocks = 0;
	sf->f_bfree = 0;
	sf->f_bavail = 0;
	sf->f_files = 0;
	sf->f_ffree = 0;
	sf->f_type = HPPFS_SUPER_MAGIC;
	return(0);
}

static struct inode *hppfs_alloc_inode(struct super_block *sb)
{
	struct hppfs_inode_info *hi;

	hi = kmalloc(sizeof(*hi), GFP_KERNEL);
	if(hi == NULL)
		return(NULL);

	*hi = ((struct hppfs_inode_info) { .proc_dentry	= NULL });
	inode_init_once(&hi->vfs_inode);
	return(&hi->vfs_inode);
}

void hppfs_delete_inode(struct inode *ino)
{
	clear_inode(ino);
}

static void hppfs_destroy_inode(struct inode *inode)
{
	kfree(HPPFS_I(inode));
}

static struct super_operations hppfs_sbops = {
	.alloc_inode	= hppfs_alloc_inode,
	.destroy_inode	= hppfs_destroy_inode,
	.read_inode	= hppfs_read_inode,
	.delete_inode	= hppfs_delete_inode,
	.statfs		= hppfs_statfs,
};

static int hppfs_readlink(struct dentry *dentry, char *buffer, int buflen)
{
	struct file *proc_file;
	struct dentry *proc_dentry;
	int ret;

	proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
	proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
	if (IS_ERR(proc_file))
		return PTR_ERR(proc_file);

	ret = proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer, buflen);

	fput(proc_file);

	return ret;
}

static void* hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
	struct file *proc_file;
	struct dentry *proc_dentry;
	void *ret;

	proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
	proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
	if (IS_ERR(proc_file))
		return proc_file;

	ret = proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);

	fput(proc_file);

	return ret;
}

static struct inode_operations hppfs_dir_iops = {
	.lookup		= hppfs_lookup,
};

static struct inode_operations hppfs_link_iops = {
	.readlink	= hppfs_readlink,
	.follow_link	= hppfs_follow_link,
};

static int init_inode(struct inode *inode, struct dentry *dentry)
{
	if(S_ISDIR(dentry->d_inode->i_mode)){
		inode->i_op = &hppfs_dir_iops;
		inode->i_fop = &hppfs_dir_fops;
	}
	else if(S_ISLNK(dentry->d_inode->i_mode)){
		inode->i_op = &hppfs_link_iops;
		inode->i_fop = &hppfs_file_fops;
	}
	else {
		inode->i_op = &hppfs_file_iops;
		inode->i_fop = &hppfs_file_fops;
	}

	HPPFS_I(inode)->proc_dentry = dentry;

	return(0);
}

static int hppfs_fill_super(struct super_block *sb, void *d, int silent)
{
	struct inode *root_inode;
	struct file_system_type *procfs;
	struct super_block *proc_sb;
	int err;

	err = -ENOENT;
	procfs = get_fs_type("proc");
	if(procfs == NULL)
		goto out;

	if(list_empty(&procfs->fs_supers))
		goto out;

	proc_sb = list_entry(procfs->fs_supers.next, struct super_block,
			     s_instances);

	sb->s_blocksize = 1024;
	sb->s_blocksize_bits = 10;
	sb->s_magic = HPPFS_SUPER_MAGIC;
	sb->s_op = &hppfs_sbops;

	root_inode = iget(sb, 0);
	if(root_inode == NULL)
		goto out;

	err = init_inode(root_inode, proc_sb->s_root);
	if(err)
		goto out_put;

	err = -ENOMEM;
	sb->s_root = d_alloc_root(root_inode);
	if(sb->s_root == NULL)
		goto out_put;

	hppfs_read_inode(root_inode);

	return(0);

 out_put:
	iput(root_inode);
 out:
	return(err);
}

static struct super_block *hppfs_read_super(struct file_system_type *type,
					     int flags, const char *dev_name,
					     void *data)
{
	return(get_sb_nodev(type, flags, data, hppfs_fill_super));
}

static struct file_system_type hppfs_type = {
	.owner 		= THIS_MODULE,
	.name 		= "hppfs",
	.get_sb 	= hppfs_read_super,
	.kill_sb	= kill_anon_super,
	.fs_flags 	= 0,
};

static int __init init_hppfs(void)
{
	return(register_filesystem(&hppfs_type));
}

static void __exit exit_hppfs(void)
{
	unregister_filesystem(&hppfs_type);
}

module_init(init_hppfs)
module_exit(exit_hppfs)
MODULE_LICENSE("GPL");

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-file-style: "linux"
 * End:
 */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
	3	* Licensed under the GPL
	4	*/
	5
	6	#include <linux/fs.h>
3f580470	7	#include <linux/file.h>
1da177e4 LT	8	#include <linux/module.h>
	9	#include <linux/init.h>
	10	#include <linux/slab.h>
	11	#include <linux/list.h>
	12	#include <linux/kernel.h>
	13	#include <linux/ctype.h>
	14	#include <linux/dcache.h>
	15	#include <linux/statfs.h>
	16	#include <asm/uaccess.h>
	17	#include <asm/fcntl.h>
	18	#include "os.h"
	19
	20	static int init_inode(struct inode inode, struct dentry dentry);
	21
	22	struct hppfs_data {
	23	struct list_head list;
	24	char contents[PAGE_SIZE - sizeof(struct list_head)];
	25	};
	26
	27	struct hppfs_private {
	28	struct file *proc_file;
	29	int host_fd;
	30	loff_t len;
	31	struct hppfs_data *contents;
	32	};
	33
	34	struct hppfs_inode_info {
	35	struct dentry *proc_dentry;
	36	struct inode vfs_inode;
	37	};
	38
	39	static inline struct hppfs_inode_info HPPFS_I(struct inode inode)
	40	{
fd589e0b	41	return container_of(inode, struct hppfs_inode_info, vfs_inode);
1da177e4 LT	42	}
	43
	44	#define HPPFS_SUPER_MAGIC 0xb00000ee
	45
	46	static struct super_operations hppfs_sbops;
	47
	48	static int is_pid(struct dentry *dentry)
	49	{
	50	struct super_block *sb;
	51	int i;
	52
	53	sb = dentry->d_sb;
	54	if((sb->s_op != &hppfs_sbops) \|\| (dentry->d_parent != sb->s_root))
	55	return(0);
	56
	57	for(i = 0; i < dentry->d_name.len; i++){
	58	if(!isdigit(dentry->d_name.name[i]))
	59	return(0);
	60	}
	61	return(1);
	62	}
	63
	64	static char dentry_name(struct dentry dentry, int extra)
	65	{
	66	struct dentry *parent;
	67	char root, name;
	68	const char *seg_name;
	69	int len, seg_len;
	70
	71	len = 0;
	72	parent = dentry;
	73	while(parent->d_parent != parent){
	74	if(is_pid(parent))
	75	len += strlen("pid") + 1;
	76	else len += parent->d_name.len + 1;
	77	parent = parent->d_parent;
	78	}
	79
	80	root = "proc";
	81	len += strlen(root);
	82	name = kmalloc(len + extra + 1, GFP_KERNEL);
	83	if(name == NULL) return(NULL);
	84
	85	name[len] = '\0';
	86	parent = dentry;
	87	while(parent->d_parent != parent){
	88	if(is_pid(parent)){
	89	seg_name = "pid";
	90	seg_len = strlen("pid");
	91	}
	92	else {
	93	seg_name = parent->d_name.name;
	94	seg_len = parent->d_name.len;
	95	}
	96
	97	len -= seg_len + 1;
	98	name[len] = '/';
	99	strncpy(&name[len + 1], seg_name, seg_len);
	100	parent = parent->d_parent;
	101	}
	102	strncpy(name, root, strlen(root));
	103	return(name);
	104	}
	105
106	struct dentry_operations hppfs_dentry_ops = {
107	};
108
109	static int file_removed(struct dentry dentry, const char file)
110	{
111	char *host_file;
112	int extra, fd;
113
114	extra = 0;
115	if(file != NULL) extra += strlen(file) + 1;
116
117	host_file = dentry_name(dentry, extra + strlen("/remove"));
118	if(host_file == NULL){
119	printk("file_removed : allocation failed\n");
120	return(-ENOMEM);
121	}
122
123	if(file != NULL){
124	strcat(host_file, "/");
125	strcat(host_file, file);
126	}
127	strcat(host_file, "/remove");
128
129	fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
130	kfree(host_file);
131	if(fd > 0){
132	os_close_file(fd);
133	return(1);
134	}
135	return(0);
136	}
137
138	static void hppfs_read_inode(struct inode *ino)
139	{
140	struct inode *proc_ino;
141
142	if(HPPFS_I(ino)->proc_dentry == NULL)
143	return;
144
145	proc_ino = HPPFS_I(ino)->proc_dentry->d_inode;
146	ino->i_uid = proc_ino->i_uid;
147	ino->i_gid = proc_ino->i_gid;
148	ino->i_atime = proc_ino->i_atime;
149	ino->i_mtime = proc_ino->i_mtime;
150	ino->i_ctime = proc_ino->i_ctime;
151	ino->i_ino = proc_ino->i_ino;
152	ino->i_mode = proc_ino->i_mode;
153	ino->i_nlink = proc_ino->i_nlink;
154	ino->i_size = proc_ino->i_size;
155	ino->i_blksize = proc_ino->i_blksize;
156	ino->i_blocks = proc_ino->i_blocks;
157	}
158
159	static struct dentry hppfs_lookup(struct inode ino, struct dentry *dentry,
160	struct nameidata *nd)
161	{
162	struct dentry proc_dentry, new, *parent;
163	struct inode *inode;
164	int err, deleted;
165
166	deleted = file_removed(dentry, NULL);
167	if(deleted < 0)
168	return(ERR_PTR(deleted));
169	else if(deleted)
170	return(ERR_PTR(-ENOENT));
171
172	err = -ENOMEM;
173	parent = HPPFS_I(ino)->proc_dentry;
1b1dcc1b	174	mutex_lock(&parent->d_inode->i_mutex);
1da177e4 LT	175	proc_dentry = d_lookup(parent, &dentry->d_name);
	176	if(proc_dentry == NULL){
	177	proc_dentry = d_alloc(parent, &dentry->d_name);
	178	if(proc_dentry == NULL){
1b1dcc1b	179	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	180	goto out;
	181	}
	182	new = (*parent->d_inode->i_op->lookup)(parent->d_inode,
	183	proc_dentry, NULL);
	184	if(new){
	185	dput(proc_dentry);
	186	proc_dentry = new;
	187	}
	188	}
1b1dcc1b	189	mutex_unlock(&parent->d_inode->i_mutex);
1da177e4 LT	190
	191	if(IS_ERR(proc_dentry))
	192	return(proc_dentry);
	193
	194	inode = iget(ino->i_sb, 0);
	195	if(inode == NULL)
	196	goto out_dput;
	197
	198	err = init_inode(inode, proc_dentry);
	199	if(err)
	200	goto out_put;
	201
	202	hppfs_read_inode(inode);
	203
	204	d_add(dentry, inode);
	205	dentry->d_op = &hppfs_dentry_ops;
	206	return(NULL);
	207
	208	out_put:
	209	iput(inode);
	210	out_dput:
	211	dput(proc_dentry);
	212	out:
	213	return(ERR_PTR(err));
	214	}
	215
	216	static struct inode_operations hppfs_file_iops = {
	217	};
	218
	219	static ssize_t read_proc(struct file file, char buf, ssize_t count,
	220	loff_t *ppos, int is_user)
	221	{
	222	ssize_t (read)(struct file , char , size_t, loff_t );
	223	ssize_t n;
	224
	225	read = file->f_dentry->d_inode->i_fop->read;
	226
	227	if(!is_user)
	228	set_fs(KERNEL_DS);
	229
	230	n = (*read)(file, buf, count, &file->f_pos);
	231
	232	if(!is_user)
	233	set_fs(USER_DS);
	234
	235	if(ppos) *ppos = file->f_pos;
8e0a2181	236	return n;
1da177e4 LT	237	}
	238
	239	static ssize_t hppfs_read_file(int fd, char *buf, ssize_t count)
	240	{
	241	ssize_t n;
	242	int cur, err;
	243	char *new_buf;
	244
	245	n = -ENOMEM;
	246	new_buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
	247	if(new_buf == NULL){
	248	printk("hppfs_read_file : kmalloc failed\n");
	249	goto out;
	250	}
	251	n = 0;
	252	while(count > 0){
	253	cur = min_t(ssize_t, count, PAGE_SIZE);
	254	err = os_read_file(fd, new_buf, cur);
	255	if(err < 0){
	256	printk("hppfs_read : read failed, errno = %d\n",
8e0a2181	257	err);
1da177e4 LT	258	n = err;
	259	goto out_free;
	260	}
	261	else if(err == 0)
	262	break;
	263
	264	if(copy_to_user(buf, new_buf, err)){
	265	n = -EFAULT;
	266	goto out_free;
	267	}
	268	n += err;
	269	count -= err;
	270	}
	271	out_free:
	272	kfree(new_buf);
	273	out:
8e0a2181	274	return n;
1da177e4 LT	275	}
	276
	277	static ssize_t hppfs_read(struct file file, char buf, size_t count,
	278	loff_t *ppos)
	279	{
	280	struct hppfs_private *hppfs = file->private_data;
	281	struct hppfs_data *data;
	282	loff_t off;
	283	int err;
	284
	285	if(hppfs->contents != NULL){
	286	if(*ppos >= hppfs->len) return(0);
	287
	288	data = hppfs->contents;
	289	off = *ppos;
	290	while(off >= sizeof(data->contents)){
	291	data = list_entry(data->list.next, struct hppfs_data,
	292	list);
	293	off -= sizeof(data->contents);
	294	}
	295
	296	if(off + count > hppfs->len)
	297	count = hppfs->len - off;
	298	copy_to_user(buf, &data->contents[off], count);
	299	*ppos += count;
	300	}
	301	else if(hppfs->host_fd != -1){
	302	err = os_seek_file(hppfs->host_fd, *ppos);
	303	if(err){
	304	printk("hppfs_read : seek failed, errno = %d\n", err);
	305	return(err);
	306	}
	307	count = hppfs_read_file(hppfs->host_fd, buf, count);
	308	if(count > 0)
	309	*ppos += count;
	310	}
	311	else count = read_proc(hppfs->proc_file, buf, count, ppos, 1);
	312
	313	return(count);
	314	}
	315
	316	static ssize_t hppfs_write(struct file file, const char buf, size_t len,
	317	loff_t *ppos)
	318	{
	319	struct hppfs_private *data = file->private_data;
	320	struct file *proc_file = data->proc_file;
	321	ssize_t (write)(struct file , const char , size_t, loff_t );
	322	int err;
	323
	324	write = proc_file->f_dentry->d_inode->i_fop->write;
	325
	326	proc_file->f_pos = file->f_pos;
	327	err = (*write)(proc_file, buf, len, &proc_file->f_pos);
	328	file->f_pos = proc_file->f_pos;
	329
	330	return(err);
	331	}
	332
	333	static int open_host_sock(char host_file, int filter_out)
	334	{
	335	char *end;
	336	int fd;
	337
	338	end = &host_file[strlen(host_file)];
339	strcpy(end, "/rw");
340	*filter_out = 1;
341	fd = os_connect_socket(host_file);
342	if(fd > 0)
343	return(fd);
344
345	strcpy(end, "/r");
346	*filter_out = 0;
347	fd = os_connect_socket(host_file);
348	return(fd);
349	}
350
351	static void free_contents(struct hppfs_data *head)
352	{
353	struct hppfs_data *data;
354	struct list_head ele, next;
355
356	if(head == NULL) return;
357
358	list_for_each_safe(ele, next, &head->list){
359	data = list_entry(ele, struct hppfs_data, list);
360	kfree(data);
361	}
362	kfree(head);
363	}
364
365	static struct hppfs_data *hppfs_get_data(int fd, int filter,
366	struct file *proc_file,
367	struct file *hppfs_file,
368	loff_t *size_out)
369	{
370	struct hppfs_data data, new, *head;
371	int n, err;
372
373	err = -ENOMEM;
374	data = kmalloc(sizeof(*data), GFP_KERNEL);
375	if(data == NULL){
376	printk("hppfs_get_data : head allocation failed\n");
377	goto failed;
378	}
379
380	INIT_LIST_HEAD(&data->list);
381
382	head = data;
383	*size_out = 0;
384
385	if(filter){
386	while((n = read_proc(proc_file, data->contents,
387	sizeof(data->contents), NULL, 0)) > 0)
388	os_write_file(fd, data->contents, n);
389	err = os_shutdown_socket(fd, 0, 1);
390	if(err){
391	printk("hppfs_get_data : failed to shut down "
392	"socket\n");
393	goto failed_free;
394	}
395	}
396	while(1){
397	n = os_read_file(fd, data->contents, sizeof(data->contents));
398	if(n < 0){
399	err = n;
400	printk("hppfs_get_data : read failed, errno = %d\n",
401	err);
402	goto failed_free;
403	}
404	else if(n == 0)
405	break;
406
407	*size_out += n;
408
409	if(n < sizeof(data->contents))
410	break;
411
412	new = kmalloc(sizeof(*data), GFP_KERNEL);
413	if(new == 0){
414	printk("hppfs_get_data : data allocation failed\n");
415	err = -ENOMEM;
416	goto failed_free;
417	}
418
419	INIT_LIST_HEAD(&new->list);
420	list_add(&new->list, &data->list);
421	data = new;
422	}
423	return(head);
424
425	failed_free:
426	free_contents(head);
427	failed:
428	return(ERR_PTR(err));
429	}
430
431	static struct hppfs_private *hppfs_data(void)
432	{
433	struct hppfs_private *data;
434
435	data = kmalloc(sizeof(*data), GFP_KERNEL);
436	if(data == NULL)
437	return(data);
438
439	*data = ((struct hppfs_private ) { .host_fd = -1,
440	.len = -1,
441	.contents = NULL } );
442	return(data);
443	}
444
445	static int file_mode(int fmode)
446	{
447	if(fmode == (FMODE_READ \| FMODE_WRITE))
448	return(O_RDWR);
449	if(fmode == FMODE_READ)
450	return(O_RDONLY);
451	if(fmode == FMODE_WRITE)
452	return(O_WRONLY);
453	return(0);
454	}
455
456	static int hppfs_open(struct inode inode, struct file file)
457	{
458	struct hppfs_private *data;
459	struct dentry *proc_dentry;
460	char *host_file;
461	int err, fd, type, filter;
462
463	err = -ENOMEM;
464	data = hppfs_data();
465	if(data == NULL)
466	goto out;
467
468	host_file = dentry_name(file->f_dentry, strlen("/rw"));
469	if(host_file == NULL)
470	goto out_free2;
471
472	proc_dentry = HPPFS_I(inode)->proc_dentry;
473
474	/* XXX This isn't closed anywhere */
475	data->proc_file = dentry_open(dget(proc_dentry), NULL,
476	file_mode(file->f_mode));
477	err = PTR_ERR(data->proc_file);
478	if(IS_ERR(data->proc_file))
479	goto out_free1;
480
481	type = os_file_type(host_file);
482	if(type == OS_TYPE_FILE){
483	fd = os_open_file(host_file, of_read(OPENFLAGS()), 0);
484	if(fd >= 0)
485	data->host_fd = fd;
486	else printk("hppfs_open : failed to open '%s', errno = %d\n",
487	host_file, -fd);
488
489	data->contents = NULL;
490	}
491	else if(type == OS_TYPE_DIR){
492	fd = open_host_sock(host_file, &filter);
493	if(fd > 0){
494	data->contents = hppfs_get_data(fd, filter,
3f580470	495	data->proc_file,
1da177e4 LT	496	file, &data->len);
	497	if(!IS_ERR(data->contents))
	498	data->host_fd = fd;
	499	}
	500	else printk("hppfs_open : failed to open a socket in "
	501	"'%s', errno = %d\n", host_file, -fd);
	502	}
	503	kfree(host_file);
	504
	505	file->private_data = data;
	506	return(0);
	507
	508	out_free1:
	509	kfree(host_file);
	510	out_free2:
	511	free_contents(data->contents);
	512	kfree(data);
	513	out:
	514	return(err);
	515	}
	516
	517	static int hppfs_dir_open(struct inode inode, struct file file)
	518	{
	519	struct hppfs_private *data;
	520	struct dentry *proc_dentry;
	521	int err;
	522
	523	err = -ENOMEM;
	524	data = hppfs_data();
	525	if(data == NULL)
	526	goto out;
	527
	528	proc_dentry = HPPFS_I(inode)->proc_dentry;
	529	data->proc_file = dentry_open(dget(proc_dentry), NULL,
	530	file_mode(file->f_mode));
	531	err = PTR_ERR(data->proc_file);
	532	if(IS_ERR(data->proc_file))
	533	goto out_free;
	534
	535	file->private_data = data;
	536	return(0);
	537
	538	out_free:
	539	kfree(data);
	540	out:
	541	return(err);
	542	}
	543
	544	static loff_t hppfs_llseek(struct file *file, loff_t off, int where)
	545	{
	546	struct hppfs_private *data = file->private_data;
3f580470	547	struct file *proc_file = data->proc_file;
1da177e4 LT	548	loff_t (llseek)(struct file , loff_t, int);
	549	loff_t ret;
	550
	551	llseek = proc_file->f_dentry->d_inode->i_fop->llseek;
	552	if(llseek != NULL){
	553	ret = (*llseek)(proc_file, off, where);
	554	if(ret < 0)
	555	return(ret);
	556	}
	557
	558	return(default_llseek(file, off, where));
	559	}
	560
	561	static struct file_operations hppfs_file_fops = {
	562	.owner = NULL,
	563	.llseek = hppfs_llseek,
	564	.read = hppfs_read,
	565	.write = hppfs_write,
	566	.open = hppfs_open,
	567	};
	568
	569	struct hppfs_dirent {
	570	void *vfs_dirent;
	571	filldir_t filldir;
	572	struct dentry *dentry;
	573	};
	574
	575	static int hppfs_filldir(void d, const char name, int size,
	576	loff_t offset, ino_t inode, unsigned int type)
	577	{
	578	struct hppfs_dirent *dirent = d;
	579
	580	if(file_removed(dirent->dentry, name))
	581	return(0);
	582
	583	return((*dirent->filldir)(dirent->vfs_dirent, name, size, offset,
	584	inode, type));
	585	}
	586
	587	static int hppfs_readdir(struct file file, void ent, filldir_t filldir)
	588	{
	589	struct hppfs_private *data = file->private_data;
3f580470	590	struct file *proc_file = data->proc_file;
1da177e4 LT	591	int (readdir)(struct file , void *, filldir_t);
	592	struct hppfs_dirent dirent = ((struct hppfs_dirent)
	593	{ .vfs_dirent = ent,
	594	.filldir = filldir,
	595	.dentry = file->f_dentry } );
	596	int err;
	597
	598	readdir = proc_file->f_dentry->d_inode->i_fop->readdir;
	599
	600	proc_file->f_pos = file->f_pos;
	601	err = (*readdir)(proc_file, &dirent, hppfs_filldir);
	602	file->f_pos = proc_file->f_pos;
	603
	604	return(err);
	605	}
	606
	607	static int hppfs_fsync(struct file file, struct dentry dentry, int datasync)
	608	{
	609	return(0);
	610	}
	611
	612	static struct file_operations hppfs_dir_fops = {
	613	.owner = NULL,
	614	.readdir = hppfs_readdir,
	615	.open = hppfs_dir_open,
	616	.fsync = hppfs_fsync,
	617	};
	618
	619	static int hppfs_statfs(struct super_block sb, struct kstatfs sf)
	620	{
	621	sf->f_blocks = 0;
	622	sf->f_bfree = 0;
	623	sf->f_bavail = 0;
	624	sf->f_files = 0;
	625	sf->f_ffree = 0;
	626	sf->f_type = HPPFS_SUPER_MAGIC;
	627	return(0);
	628	}
	629
	630	static struct inode hppfs_alloc_inode(struct super_block sb)
	631	{
	632	struct hppfs_inode_info *hi;
	633
	634	hi = kmalloc(sizeof(*hi), GFP_KERNEL);
	635	if(hi == NULL)
	636	return(NULL);
	637
	638	*hi = ((struct hppfs_inode_info) { .proc_dentry = NULL });
	639	inode_init_once(&hi->vfs_inode);
	640	return(&hi->vfs_inode);
	641	}
	642
	643	void hppfs_delete_inode(struct inode *ino)
	644	{
	645	clear_inode(ino);
	646	}
	647
	648	static void hppfs_destroy_inode(struct inode *inode)
	649	{
	650	kfree(HPPFS_I(inode));
	651	}
	652
	653	static struct super_operations hppfs_sbops = {
	654	.alloc_inode = hppfs_alloc_inode,
655	.destroy_inode = hppfs_destroy_inode,
656	.read_inode = hppfs_read_inode,
657	.delete_inode = hppfs_delete_inode,
658	.statfs = hppfs_statfs,
659	};
660
661	static int hppfs_readlink(struct dentry dentry, char buffer, int buflen)
662	{
663	struct file *proc_file;
664	struct dentry *proc_dentry;
fd589e0b	665	int ret;
1da177e4 LT	666
	667	proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
	668	proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
fd589e0b PBG	669	if (IS_ERR(proc_file))
fd589e0b PBG	670	return PTR_ERR(proc_file);
1da177e4	671
fd589e0b	672	ret = proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer, buflen);
1da177e4 LT	673
	674	fput(proc_file);
	675
fd589e0b	676	return ret;
1da177e4 LT	677	}
1da177e4 LT	678
d7a60d50	679	static void* hppfs_follow_link(struct dentry dentry, struct nameidata nd)
1da177e4 LT	680	{
	681	struct file *proc_file;
	682	struct dentry *proc_dentry;
d7a60d50	683	void *ret;
1da177e4 LT	684
	685	proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry;
	686	proc_file = dentry_open(dget(proc_dentry), NULL, O_RDONLY);
fd589e0b PBG	687	if (IS_ERR(proc_file))
fd589e0b PBG	688	return proc_file;
d7a60d50	689
fd589e0b	690	ret = proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd);
1da177e4 LT	691
	692	fput(proc_file);
	693
d7a60d50	694	return ret;
1da177e4 LT	695	}
	696
	697	static struct inode_operations hppfs_dir_iops = {
	698	.lookup = hppfs_lookup,
	699	};
	700
	701	static struct inode_operations hppfs_link_iops = {
	702	.readlink = hppfs_readlink,
	703	.follow_link = hppfs_follow_link,
	704	};
	705
	706	static int init_inode(struct inode inode, struct dentry dentry)
	707	{
	708	if(S_ISDIR(dentry->d_inode->i_mode)){
	709	inode->i_op = &hppfs_dir_iops;
	710	inode->i_fop = &hppfs_dir_fops;
	711	}
	712	else if(S_ISLNK(dentry->d_inode->i_mode)){
	713	inode->i_op = &hppfs_link_iops;
	714	inode->i_fop = &hppfs_file_fops;
	715	}
	716	else {
	717	inode->i_op = &hppfs_file_iops;
	718	inode->i_fop = &hppfs_file_fops;
	719	}
	720
	721	HPPFS_I(inode)->proc_dentry = dentry;
	722
	723	return(0);
	724	}
	725
	726	static int hppfs_fill_super(struct super_block sb, void d, int silent)
	727	{
	728	struct inode *root_inode;
	729	struct file_system_type *procfs;
	730	struct super_block *proc_sb;
	731	int err;
	732
	733	err = -ENOENT;
	734	procfs = get_fs_type("proc");
	735	if(procfs == NULL)
	736	goto out;
	737
	738	if(list_empty(&procfs->fs_supers))
	739	goto out;
	740
	741	proc_sb = list_entry(procfs->fs_supers.next, struct super_block,
	742	s_instances);
	743
	744	sb->s_blocksize = 1024;
	745	sb->s_blocksize_bits = 10;
	746	sb->s_magic = HPPFS_SUPER_MAGIC;
	747	sb->s_op = &hppfs_sbops;
	748
	749	root_inode = iget(sb, 0);
	750	if(root_inode == NULL)
	751	goto out;
	752
	753	err = init_inode(root_inode, proc_sb->s_root);
	754	if(err)
	755	goto out_put;
	756
	757	err = -ENOMEM;
	758	sb->s_root = d_alloc_root(root_inode);
759	if(sb->s_root == NULL)
760	goto out_put;
761
762	hppfs_read_inode(root_inode);
763
764	return(0);
765
766	out_put:
767	iput(root_inode);
768	out:
769	return(err);
770	}
771
772	static struct super_block hppfs_read_super(struct file_system_type type,
773	int flags, const char *dev_name,
774	void *data)
775	{
776	return(get_sb_nodev(type, flags, data, hppfs_fill_super));
777	}
778
779	static struct file_system_type hppfs_type = {
780	.owner = THIS_MODULE,
781	.name = "hppfs",
782	.get_sb = hppfs_read_super,
783	.kill_sb = kill_anon_super,
784	.fs_flags = 0,
785	};
786
787	static int __init init_hppfs(void)
788	{
789	return(register_filesystem(&hppfs_type));
790	}
791
792	static void __exit exit_hppfs(void)
793	{
794	unregister_filesystem(&hppfs_type);
795	}
796
797	module_init(init_hppfs)
798	module_exit(exit_hppfs)
799	MODULE_LICENSE("GPL");
800
801	/*
802	* Overrides for Emacs so that we follow Linus's tabbing style.
803	* Emacs will notice this stuff at the end of the file and automatically
804	* adjust the settings for this buffer only. This must remain at the end
805	* of the file.
806	* ---------------------------------------------------------------------------
807	* Local variables:
808	* c-file-style: "linux"
809	* End:
810	*/