dentry.c
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/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 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 version 2.
*/
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/namei.h>
#include <linux/crc32.h>
#include "gfs2.h"
#include "incore.h"
#include "dir.h"
#include "glock.h"
#include "super.h"
#include "util.h"
#include "inode.h"
/**
* gfs2_drevalidate - Check directory lookup consistency
* @dentry: the mapping to check
* @flags: lookup flags
*
* 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, unsigned int flags)
{
struct dentry *parent;
struct gfs2_sbd *sdp;
struct gfs2_inode *dip;
struct inode *inode;
struct gfs2_holder d_gh;
struct gfs2_inode *ip = NULL;
int error;
int had_lock = 0;
if (flags & LOOKUP_RCU)
return -ECHILD;
parent = dget_parent(dentry);
sdp = GFS2_SB(d_inode(parent));
dip = GFS2_I(d_inode(parent));
inode = d_inode(dentry);
if (inode) {
if (is_bad_inode(inode))
goto invalid;
ip = GFS2_I(inode);
}
if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
goto valid;
had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
if (!had_lock) {
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
if (error)
goto fail;
}
error = gfs2_dir_check(d_inode(parent), &dentry->d_name, ip);
switch (error) {
case 0:
if (!inode)
goto invalid_gunlock;
break;
case -ENOENT:
if (!inode)
goto valid_gunlock;
goto invalid_gunlock;
default:
goto fail_gunlock;
}
valid_gunlock:
if (!had_lock)
gfs2_glock_dq_uninit(&d_gh);
valid:
dput(parent);
return 1;
invalid_gunlock:
if (!had_lock)
gfs2_glock_dq_uninit(&d_gh);
invalid:
dput(parent);
return 0;
fail_gunlock:
gfs2_glock_dq_uninit(&d_gh);
fail:
dput(parent);
return 0;
}
static int gfs2_dhash(const struct dentry *dentry, struct qstr *str)
{
str->hash = gfs2_disk_hash(str->name, str->len);
return 0;
}
static int gfs2_dentry_delete(const struct dentry *dentry)
{
struct gfs2_inode *ginode;
if (d_really_is_negative(dentry))
return 0;
ginode = GFS2_I(d_inode(dentry));
if (!ginode->i_iopen_gh.gh_gl)
return 0;
if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags))
return 1;
return 0;
}
const struct dentry_operations gfs2_dops = {
.d_revalidate = gfs2_drevalidate,
.d_hash = gfs2_dhash,
.d_delete = gfs2_dentry_delete,
};