/* -*- linux-c -*- --------------------------------------------------------- *
   *
   * linux/fs/autofs/inode.c
   *
   *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
   *
   * This file is part of the Linux kernel and is made available under
   * the terms of the GNU General Public License, version 2, or at your
   * option, any later version, incorporated herein by reference.
   *
   * ------------------------------------------------------------------------- */
  
  #include <linux/kernel.h>
  #include <linux/mm.h>
  #include <linux/slab.h>
  #include <linux/file.h>
  #include <linux/parser.h>
  #include <linux/bitops.h>

  #include <linux/magic.h>

  #include "autofs_i.h"
  #include <linux/module.h>

  void autofs_kill_sb(struct super_block *sb)

  {
  	struct autofs_sb_info *sbi = autofs_sbi(sb);
  	unsigned int n;

  	/*
  	 * In the event of a failure in get_sb_nodev the superblock
  	 * info is not present so nothing else has been setup, so

  	 * just call kill_anon_super when we are called from
  	 * deactivate_super.

  	 */
  	if (!sbi)

  		goto out_kill_sb;

  	if (!sbi->catatonic)

  		autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */

  	put_pid(sbi->oz_pgrp);

  	autofs_hash_nuke(sbi);

  	for (n = 0; n < AUTOFS_MAX_SYMLINKS; n++) {
  		if (test_bit(n, sbi->symlink_bitmap))

  			kfree(sbi->symlink[n].data);
  	}
  
  	kfree(sb->s_fs_info);

  out_kill_sb:

  	DPRINTK(("autofs: shutting down
  "));

  	kill_anon_super(sb);

  }
  
  static void autofs_read_inode(struct inode *inode);

  static const struct super_operations autofs_sops = {

  	.read_inode	= autofs_read_inode,

  	.statfs		= simple_statfs,
  };
  
  enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};
  
  static match_table_t autofs_tokens = {
  	{Opt_fd, "fd=%u"},
  	{Opt_uid, "uid=%u"},
  	{Opt_gid, "gid=%u"},
  	{Opt_pgrp, "pgrp=%u"},
  	{Opt_minproto, "minproto=%u"},
  	{Opt_maxproto, "maxproto=%u"},
  	{Opt_err, NULL}
  };

  static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
  		pid_t *pgrp, int *minproto, int *maxproto)

  {
  	char *p;
  	substring_t args[MAX_OPT_ARGS];
  	int option;
  
  	*uid = current->uid;
  	*gid = current->gid;
  	*pgrp = process_group(current);
  
  	*minproto = *maxproto = AUTOFS_PROTO_VERSION;
  
  	*pipefd = -1;
  
  	if (!options)
  		return 1;
  
  	while ((p = strsep(&options, ",")) != NULL) {
  		int token;
  		if (!*p)
  			continue;
  
  		token = match_token(p, autofs_tokens, args);
  		switch (token) {
  		case Opt_fd:
  			if (match_int(&args[0], &option))
  				return 1;
  			*pipefd = option;
  			break;
  		case Opt_uid:
  			if (match_int(&args[0], &option))
  				return 1;
  			*uid = option;
  			break;
  		case Opt_gid:
  			if (match_int(&args[0], &option))
  				return 1;
  			*gid = option;
  			break;
  		case Opt_pgrp:
  			if (match_int(&args[0], &option))
  				return 1;
  			*pgrp = option;
  			break;
  		case Opt_minproto:
  			if (match_int(&args[0], &option))
  				return 1;
  			*minproto = option;
  			break;
  		case Opt_maxproto:
  			if (match_int(&args[0], &option))
  				return 1;
  			*maxproto = option;
  			break;
  		default:
  			return 1;
  		}
  	}
  	return (*pipefd < 0);
  }
  
  int autofs_fill_super(struct super_block *s, void *data, int silent)
  {
  	struct inode * root_inode;
  	struct dentry * root;
  	struct file * pipe;
  	int pipefd;
  	struct autofs_sb_info *sbi;
  	int minproto, maxproto;

  	pid_t pgid;

  	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);

  	if (!sbi)

  		goto fail_unlock;

  	DPRINTK(("autofs: starting up, sbi = %p
  ",sbi));
  
  	s->s_fs_info = sbi;
  	sbi->magic = AUTOFS_SBI_MAGIC;

  	sbi->pipe = NULL;
  	sbi->catatonic = 1;

  	sbi->exp_timeout = 0;

  	autofs_initialize_hash(&sbi->dirhash);
  	sbi->queues = NULL;
  	memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
  	sbi->next_dir_ino = AUTOFS_FIRST_DIR_INO;
  	s->s_blocksize = 1024;
  	s->s_blocksize_bits = 10;
  	s->s_magic = AUTOFS_SUPER_MAGIC;
  	s->s_op = &autofs_sops;
  	s->s_time_gran = 1;

  	sbi->sb = s;

  
  	root_inode = iget(s, AUTOFS_ROOT_INO);
  	root = d_alloc_root(root_inode);
  	pipe = NULL;
  
  	if (!root)
  		goto fail_iput;
  
  	/* Can this call block?  - WTF cares? s is locked. */

  	if (parse_options(data, &pipefd, &root_inode->i_uid,

  				&root_inode->i_gid, &pgid, &minproto,

  				&maxproto)) {

  		printk("autofs: called with bogus options
  ");
  		goto fail_dput;
  	}
  
  	/* Couldn't this be tested earlier? */

  	if (minproto > AUTOFS_PROTO_VERSION ||
  	     maxproto < AUTOFS_PROTO_VERSION) {

  		printk("autofs: kernel does not match daemon version
  ");
  		goto fail_dput;
  	}

  	DPRINTK(("autofs: pipe fd = %d, pgrp = %u
  ", pipefd, pgid));
  	sbi->oz_pgrp = find_get_pid(pgid);
  
  	if (!sbi->oz_pgrp) {
  		printk("autofs: could not find process group %d
  ", pgid);
  		goto fail_dput;
  	}

  	pipe = fget(pipefd);
  	

  	if (!pipe) {

  		printk("autofs: could not open pipe file descriptor
  ");

  		goto fail_put_pid;

  	}

  	if (!pipe->f_op || !pipe->f_op->write)

  		goto fail_fput;
  	sbi->pipe = pipe;

  	sbi->catatonic = 0;

  
  	/*
  	 * Success! Install the root dentry now to indicate completion.
  	 */
  	s->s_root = root;
  	return 0;
  
  fail_fput:
  	printk("autofs: pipe file descriptor does not contain proper ops
  ");
  	fput(pipe);

  fail_put_pid:
  	put_pid(sbi->oz_pgrp);

  fail_dput:
  	dput(root);
  	goto fail_free;
  fail_iput:
  	printk("autofs: get root dentry failed
  ");
  	iput(root_inode);
  fail_free:
  	kfree(sbi);

  	s->s_fs_info = NULL;

  fail_unlock:
  	return -EINVAL;
  }
  
  static void autofs_read_inode(struct inode *inode)
  {
  	ino_t ino = inode->i_ino;
  	unsigned int n;
  	struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb);
  
  	/* Initialize to the default case (stub directory) */
  
  	inode->i_op = &simple_dir_inode_operations;
  	inode->i_fop = &simple_dir_operations;
  	inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
  	inode->i_nlink = 2;
  	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
  	inode->i_blocks = 0;

  	if (ino == AUTOFS_ROOT_INO) {

  		inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
  		inode->i_op = &autofs_root_inode_operations;
  		inode->i_fop = &autofs_root_operations;
  		inode->i_uid = inode->i_gid = 0; /* Changed in read_super */
  		return;
  	} 
  	
  	inode->i_uid = inode->i_sb->s_root->d_inode->i_uid;
  	inode->i_gid = inode->i_sb->s_root->d_inode->i_gid;
  	

  	if (ino >= AUTOFS_FIRST_SYMLINK && ino < AUTOFS_FIRST_DIR_INO) {

  		/* Symlink inode - should be in symlink list */
  		struct autofs_symlink *sl;
  
  		n = ino - AUTOFS_FIRST_SYMLINK;

  		if (n >= AUTOFS_MAX_SYMLINKS || !test_bit(n,sbi->symlink_bitmap)) {

  			printk("autofs: Looking for bad symlink inode %u
  ", (unsigned int) ino);
  			return;
  		}
  		
  		inode->i_op = &autofs_symlink_inode_operations;
  		sl = &sbi->symlink[n];

  		inode->i_private = sl;

  		inode->i_mode = S_IFLNK | S_IRWXUGO;
  		inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = sl->mtime;
  		inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
  		inode->i_size = sl->len;
  		inode->i_nlink = 1;
  	}
  }