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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/smp_lock.h>
#include <asm/semaphore.h>
#include "gfs2.h"
#include "dir.h"
#include "glock.h"
#include "ops_dentry.h"
/**
* gfs2_drevalidate - Check directory lookup consistency
* @dentry: the mapping to check
* @nd:
*
* Check to make sure the lookup necessary to arrive at this inode from its
* parent is still good.
*
* Returns: 1 if the dentry is ok, 0 if it isn't
*/
static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
{
struct dentry *parent = dget_parent(dentry);
struct gfs2_inode *dip = get_v2ip(parent->d_inode);
struct gfs2_sbd *sdp = dip->i_sbd;
struct inode *inode;
struct gfs2_holder d_gh;
struct gfs2_inode *ip;
struct gfs2_inum inum;
unsigned int type;
int error;
lock_kernel();
atomic_inc(&sdp->sd_ops_dentry);
inode = dentry->d_inode;
if (inode && is_bad_inode(inode))
goto invalid;
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
if (error)
goto fail;
error = gfs2_dir_search(dip, &dentry->d_name, &inum, &type);
switch (error) {
case 0:
if (!inode)
goto invalid_gunlock;
break;
case -ENOENT:
if (!inode)
goto valid_gunlock;
goto invalid_gunlock;
default:
goto fail_gunlock;
}
ip = get_v2ip(inode);
if (!gfs2_inum_equal(&ip->i_num, &inum))
goto invalid_gunlock;
if (IF2DT(ip->i_di.di_mode) != type) {
gfs2_consist_inode(dip);
goto fail_gunlock;
}
valid_gunlock:
gfs2_glock_dq_uninit(&d_gh);
valid:
unlock_kernel();
dput(parent);
return 1;
invalid_gunlock:
gfs2_glock_dq_uninit(&d_gh);
invalid:
if (inode && S_ISDIR(inode->i_mode)) {
if (have_submounts(dentry))
goto valid;
shrink_dcache_parent(dentry);
}
d_drop(dentry);
unlock_kernel();
dput(parent);
return 0;
fail_gunlock:
gfs2_glock_dq_uninit(&d_gh);
fail:
unlock_kernel();
dput(parent);
return 0;
}
struct dentry_operations gfs2_dops = {
.d_revalidate = gfs2_drevalidate,
};
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