linux-imx

/* getroot.c: get the root dentry for an NFS mount

 *

 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.

 * Written by David Howells (dhowells@redhat.com)

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */

​

#include <linux/module.h>

#include <linux/init.h>

​

#include <linux/time.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/string.h>

#include <linux/stat.h>

#include <linux/errno.h>

#include <linux/unistd.h>

#include <linux/sunrpc/clnt.h>

#include <linux/sunrpc/stats.h>

#include <linux/nfs_fs.h>

#include <linux/nfs_mount.h>

#include <linux/lockd/bind.h>

#include <linux/seq_file.h>

#include <linux/mount.h>

#include <linux/vfs.h>

#include <linux/namei.h>

#include <linux/security.h>

​

#include <linux/uaccess.h>

​

#include "internal.h"

​

#define NFSDBG_FACILITY     NFSDBG_CLIENT

​

/*

 * Set the superblock root dentry.

 * Note that this function frees the inode in case of error.

 */

static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *inode)

{

    /* The mntroot acts as the dummy root dentry for this superblock */

    if (sb->s_root == NULL) {

        sb->s_root = d_make_root(inode);

        if (sb->s_root == NULL)

            return -ENOMEM;

        ihold(inode);

        /*

         * Ensure that this dentry is invisible to d_find_alias().

         * Otherwise, it may be spliced into the tree by

         * d_splice_alias if a parent directory from the same

         * filesystem gets mounted at a later time.

         * This again causes shrink_dcache_for_umount_subtree() to

         * Oops, since the test for IS_ROOT() will fail.

         */

        spin_lock(&d_inode(sb->s_root)->i_lock);

        spin_lock(&sb->s_root->d_lock);

        hlist_del_init(&sb->s_root->d_u.d_alias);

        spin_unlock(&sb->s_root->d_lock);

        spin_unlock(&d_inode(sb->s_root)->i_lock);