/* -*- c -*- --------------------------------------------------------------- *
   *
   * linux/fs/autofs/inode.c
   *
   *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved

   *  Copyright 2005-2006 Ian Kent <raven@themaw.net>

   *
   * 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/slab.h>
  #include <linux/file.h>

  #include <linux/seq_file.h>

  #include <linux/pagemap.h>
  #include <linux/parser.h>
  #include <linux/bitops.h>

  #include <linux/magic.h>

  #include "autofs_i.h"
  #include <linux/module.h>
  
  static void ino_lnkfree(struct autofs_info *ino)
  {

  	if (ino->u.symlink) {
  		kfree(ino->u.symlink);
  		ino->u.symlink = NULL;
  	}

  }
  
  struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
  				     struct autofs_sb_info *sbi, mode_t mode)
  {
  	int reinit = 1;
  
  	if (ino == NULL) {
  		reinit = 0;
  		ino = kmalloc(sizeof(*ino), GFP_KERNEL);
  	}
  
  	if (ino == NULL)
  		return NULL;

  	if (!reinit) {
  		ino->flags = 0;
  		ino->inode = NULL;
  		ino->dentry = NULL;
  		ino->size = 0;
  		INIT_LIST_HEAD(&ino->active);

  		ino->active_count = 0;

  		INIT_LIST_HEAD(&ino->expiring);
  		atomic_set(&ino->count, 0);
  	}

  	ino->uid = 0;
  	ino->gid = 0;

  	ino->mode = mode;

  	ino->last_used = jiffies;
  
  	ino->sbi = sbi;
  
  	if (reinit && ino->free)
  		(ino->free)(ino);
  
  	memset(&ino->u, 0, sizeof(ino->u));
  
  	ino->free = NULL;
  
  	if (S_ISLNK(mode))
  		ino->free = ino_lnkfree;
  
  	return ino;
  }
  
  void autofs4_free_ino(struct autofs_info *ino)
  {

  	struct autofs_info *p_ino;

  	if (ino->dentry) {
  		ino->dentry->d_fsdata = NULL;

  		if (ino->dentry->d_inode) {
  			struct dentry *parent = ino->dentry->d_parent;
  			if (atomic_dec_and_test(&ino->count)) {
  				p_ino = autofs4_dentry_ino(parent);
  				if (p_ino && parent != ino->dentry)
  					atomic_dec(&p_ino->count);
  			}

  			dput(ino->dentry);

  		}

  		ino->dentry = NULL;
  	}
  	if (ino->free)
  		(ino->free)(ino);
  	kfree(ino);
  }

  void autofs4_kill_sb(struct super_block *sb)

  {
  	struct autofs_sb_info *sbi = autofs4_sbi(sb);

  	/*
  	 * 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;

  	/* Free wait queues, close pipe */
  	autofs4_catatonic_mode(sbi);

  	sb->s_fs_info = NULL;

  	kfree(sbi);

  out_kill_sb:

  	DPRINTK("shutting down");

  	kill_litter_super(sb);

  }

  static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
  {
  	struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb);

  	struct inode *root_inode = mnt->mnt_sb->s_root->d_inode;

  
  	if (!sbi)
  		return 0;
  
  	seq_printf(m, ",fd=%d", sbi->pipefd);

  	if (root_inode->i_uid != 0)
  		seq_printf(m, ",uid=%u", root_inode->i_uid);
  	if (root_inode->i_gid != 0)
  		seq_printf(m, ",gid=%u", root_inode->i_gid);

  	seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
  	seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
  	seq_printf(m, ",minproto=%d", sbi->min_proto);
  	seq_printf(m, ",maxproto=%d", sbi->max_proto);

  	if (autofs_type_offset(sbi->type))

  		seq_printf(m, ",offset");

  	else if (autofs_type_direct(sbi->type))

  		seq_printf(m, ",direct");
  	else
  		seq_printf(m, ",indirect");

  	return 0;
  }

  static const struct super_operations autofs4_sops = {

  	.statfs		= simple_statfs,

  	.show_options	= autofs4_show_options,

  };

  enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
  	Opt_indirect, Opt_direct, Opt_offset};

  static const match_table_t 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_indirect, "indirect"},
  	{Opt_direct, "direct"},
  	{Opt_offset, "offset"},

  	{Opt_err, NULL}
  };
  
  static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,

  		pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto)

  {
  	char *p;
  	substring_t args[MAX_OPT_ARGS];
  	int option;

  	*uid = current_uid();
  	*gid = current_gid();

  	*pgrp = task_pgrp_nr(current);

  
  	*minproto = AUTOFS_MIN_PROTO_VERSION;
  	*maxproto = AUTOFS_MAX_PROTO_VERSION;
  
  	*pipefd = -1;
  
  	if (!options)
  		return 1;
  
  	while ((p = strsep(&options, ",")) != NULL) {
  		int token;
  		if (!*p)
  			continue;
  
  		token = match_token(p, tokens, args);
  		switch (token) {
  		case Opt_fd:
  			if (match_int(args, pipefd))
  				return 1;
  			break;
  		case Opt_uid:
  			if (match_int(args, &option))
  				return 1;
  			*uid = option;
  			break;
  		case Opt_gid:
  			if (match_int(args, &option))
  				return 1;
  			*gid = option;
  			break;
  		case Opt_pgrp:
  			if (match_int(args, &option))
  				return 1;
  			*pgrp = option;
  			break;
  		case Opt_minproto:
  			if (match_int(args, &option))
  				return 1;
  			*minproto = option;
  			break;
  		case Opt_maxproto:
  			if (match_int(args, &option))
  				return 1;
  			*maxproto = option;
  			break;

  		case Opt_indirect:

  			set_autofs_type_indirect(type);

  			break;
  		case Opt_direct:

  			set_autofs_type_direct(type);

  			break;
  		case Opt_offset:

  			set_autofs_type_offset(type);

  			break;

  		default:
  			return 1;
  		}
  	}
  	return (*pipefd < 0);
  }
  
  static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
  {
  	struct autofs_info *ino;
  
  	ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755);
  	if (!ino)
  		return NULL;
  
  	return ino;
  }

  static const struct dentry_operations autofs4_sb_dentry_operations = {

  	.d_release      = autofs4_dentry_release,
  };

  int autofs4_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;
  	struct autofs_info *ino;

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

  	if (!sbi)

  		goto fail_unlock;
  	DPRINTK("starting up, sbi = %p",sbi);

  	s->s_fs_info = sbi;
  	sbi->magic = AUTOFS_SBI_MAGIC;

  	sbi->pipefd = -1;

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

  	sbi->exp_timeout = 0;

  	sbi->oz_pgrp = task_pgrp_nr(current);

  	sbi->sb = s;
  	sbi->version = 0;
  	sbi->sub_version = 0;

  	set_autofs_type_indirect(&sbi->type);

  	sbi->min_proto = 0;
  	sbi->max_proto = 0;

  	mutex_init(&sbi->wq_mutex);

  	spin_lock_init(&sbi->fs_lock);

  	sbi->queues = NULL;

  	spin_lock_init(&sbi->lookup_lock);

  	INIT_LIST_HEAD(&sbi->active_list);

  	INIT_LIST_HEAD(&sbi->expiring_list);

  	s->s_blocksize = 1024;
  	s->s_blocksize_bits = 10;
  	s->s_magic = AUTOFS_SUPER_MAGIC;
  	s->s_op = &autofs4_sops;
  	s->s_time_gran = 1;
  
  	/*
  	 * Get the root inode and dentry, but defer checking for errors.
  	 */
  	ino = autofs4_mkroot(sbi);
  	if (!ino)
  		goto fail_free;
  	root_inode = autofs4_get_inode(s, ino);

  	if (!root_inode)

  		goto fail_ino;

  	root = d_alloc_root(root_inode);

  	if (!root)
  		goto fail_iput;

  	pipe = NULL;
  
  	root->d_op = &autofs4_sb_dentry_operations;
  	root->d_fsdata = ino;

  
  	/* Can this call block? */

  	if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
  				&sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
  				&sbi->max_proto)) {

  		printk("autofs: called with bogus options
  ");
  		goto fail_dput;
  	}

  	root_inode->i_fop = &autofs4_root_operations;

  	root_inode->i_op = autofs_type_trigger(sbi->type) ?

  			&autofs4_direct_root_inode_operations :
  			&autofs4_indirect_root_inode_operations;

  	/* Couldn't this be tested earlier? */

  	if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
  	    sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {

  		printk("autofs: kernel does not match daemon version "
  		       "daemon (%d, %d) kernel (%d, %d)
  ",

  			sbi->min_proto, sbi->max_proto,

  			AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
  		goto fail_dput;
  	}

  	/* Establish highest kernel protocol version */
  	if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
  		sbi->version = AUTOFS_MAX_PROTO_VERSION;
  	else
  		sbi->version = sbi->max_proto;

  	sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
  
  	DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
  	pipe = fget(pipefd);
  	

  	if (!pipe) {

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

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

  		goto fail_fput;
  	sbi->pipe = pipe;

  	sbi->pipefd = pipefd;

  	sbi->catatonic = 0;

  
  	/*
  	 * Success! Install the root dentry now to indicate completion.
  	 */
  	s->s_root = root;
  	return 0;
  	
  	/*
  	 * Failure ... clean up.
  	 */
  fail_fput:
  	printk("autofs: pipe file descriptor does not contain proper ops
  ");
  	fput(pipe);
  	/* fall through */
  fail_dput:
  	dput(root);
  	goto fail_free;
  fail_iput:
  	printk("autofs: get root dentry failed
  ");
  	iput(root_inode);

  fail_ino:
  	kfree(ino);

  fail_free:
  	kfree(sbi);

  	s->s_fs_info = NULL;

  fail_unlock:
  	return -EINVAL;
  }
  
  struct inode *autofs4_get_inode(struct super_block *sb,
  				struct autofs_info *inf)
  {
  	struct inode *inode = new_inode(sb);
  
  	if (inode == NULL)
  		return NULL;
  
  	inf->inode = inode;
  	inode->i_mode = inf->mode;
  	if (sb->s_root) {
  		inode->i_uid = sb->s_root->d_inode->i_uid;
  		inode->i_gid = sb->s_root->d_inode->i_gid;

  	}

  	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  
  	if (S_ISDIR(inf->mode)) {
  		inode->i_nlink = 2;
  		inode->i_op = &autofs4_dir_inode_operations;
  		inode->i_fop = &autofs4_dir_operations;
  	} else if (S_ISLNK(inf->mode)) {
  		inode->i_size = inf->size;
  		inode->i_op = &autofs4_symlink_inode_operations;
  	}
  
  	return inode;
  }