[net-next-2.6.git] / fs / gfs2 / ops_dentry.c

/*
 * 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 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 <linux/gfs2_ondisk.h>
#include <linux/crc32.h>

#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "dir.h"
#include "glock.h"
#include "ops_dentry.h"
#include "util.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_sbd *sdp = parent->d_inode->i_sb->s_fs_info;
	struct gfs2_inode *dip = parent->d_inode->u.generic_ip;
	struct inode *inode = dentry->d_inode;
	struct gfs2_holder d_gh;
	struct gfs2_inode *ip;
	struct gfs2_inum inum;
	unsigned int type;
	int error;

	if (inode && is_bad_inode(inode))
		goto invalid;

	if (sdp->sd_args.ar_localcaching)
		goto valid;

	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
	if (error)
		goto fail;

	error = gfs2_dir_search(parent->d_inode, &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 = inode->u.generic_ip;

	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:
	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);

	dput(parent);
	return 0;

 fail_gunlock:
	gfs2_glock_dq_uninit(&d_gh);

 fail:
	dput(parent);
	return 0;
}

static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
{
	str->hash = gfs2_disk_hash(str->name, str->len);
	return 0;
}

struct dentry_operations gfs2_dops = {
	.d_revalidate = gfs2_drevalidate,
	.d_hash = gfs2_dhash,
};
Commit	Line	Data
b3b94faa DT	1	/*
b3b94faa DT	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3a8a9a10	3	* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
b3b94faa DT	4	*
	5	* This copyrighted material is made available to anyone wishing to use,
	6	* modify, copy, or redistribute it subject to the terms and conditions
	7	* of the GNU General Public License v.2.
	8	*/
	9
	10	#include <linux/sched.h>
	11	#include <linux/slab.h>
	12	#include <linux/spinlock.h>
	13	#include <linux/completion.h>
	14	#include <linux/buffer_head.h>
	15	#include <linux/smp_lock.h>
5c676f6d	16	#include <linux/gfs2_ondisk.h>
71b86f56	17	#include <linux/crc32.h>
b3b94faa DT	18
b3b94faa DT	19	#include "gfs2.h"
5c676f6d SW	20	#include "lm_interface.h"
5c676f6d SW	21	#include "incore.h"
b3b94faa DT	22	#include "dir.h"
	23	#include "glock.h"
	24	#include "ops_dentry.h"
5c676f6d	25	#include "util.h"
b3b94faa DT	26
	27	/**
	28	* gfs2_drevalidate - Check directory lookup consistency
	29	* @dentry: the mapping to check
	30	* @nd:
	31	*
	32	* Check to make sure the lookup necessary to arrive at this inode from its
	33	* parent is still good.
	34	*
	35	* Returns: 1 if the dentry is ok, 0 if it isn't
	36	*/
	37
	38	static int gfs2_drevalidate(struct dentry dentry, struct nameidata nd)
	39	{
	40	struct dentry *parent = dget_parent(dentry);
c752666c	41	struct gfs2_sbd *sdp = parent->d_inode->i_sb->s_fs_info;
5c676f6d	42	struct gfs2_inode *dip = parent->d_inode->u.generic_ip;
c752666c	43	struct inode *inode = dentry->d_inode;
b3b94faa DT	44	struct gfs2_holder d_gh;
	45	struct gfs2_inode *ip;
	46	struct gfs2_inum inum;
	47	unsigned int type;
	48	int error;
	49
b3b94faa DT	50	if (inode && is_bad_inode(inode))
	51	goto invalid;
	52
c752666c SW	53	if (sdp->sd_args.ar_localcaching)
	54	goto valid;
	55
b3b94faa DT	56	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
	57	if (error)
	58	goto fail;
	59
c752666c	60	error = gfs2_dir_search(parent->d_inode, &dentry->d_name, &inum, &type);
b3b94faa DT	61	switch (error) {
	62	case 0:
	63	if (!inode)
	64	goto invalid_gunlock;
	65	break;
	66	case -ENOENT:
	67	if (!inode)
	68	goto valid_gunlock;
	69	goto invalid_gunlock;
	70	default:
	71	goto fail_gunlock;
	72	}
	73
5c676f6d	74	ip = inode->u.generic_ip;
b3b94faa DT	75
	76	if (!gfs2_inum_equal(&ip->i_num, &inum))
	77	goto invalid_gunlock;
	78
	79	if (IF2DT(ip->i_di.di_mode) != type) {
	80	gfs2_consist_inode(dip);
	81	goto fail_gunlock;
	82	}
	83
	84	valid_gunlock:
	85	gfs2_glock_dq_uninit(&d_gh);
	86
	87	valid:
b3b94faa DT	88	dput(parent);
	89	return 1;
	90
	91	invalid_gunlock:
	92	gfs2_glock_dq_uninit(&d_gh);
	93
	94	invalid:
	95	if (inode && S_ISDIR(inode->i_mode)) {
	96	if (have_submounts(dentry))
	97	goto valid;
	98	shrink_dcache_parent(dentry);
	99	}
	100	d_drop(dentry);
	101
b3b94faa DT	102	dput(parent);
	103	return 0;
	104
	105	fail_gunlock:
	106	gfs2_glock_dq_uninit(&d_gh);
	107
	108	fail:
b3b94faa DT	109	dput(parent);
	110	return 0;
	111	}
	112
c752666c SW	113	static int gfs2_dhash(struct dentry dentry, struct qstr str)
	114	{
	115	str->hash = gfs2_disk_hash(str->name, str->len);
	116	return 0;
	117	}
	118
b3b94faa DT	119	struct dentry_operations gfs2_dops = {
b3b94faa DT	120	.d_revalidate = gfs2_drevalidate,
c752666c	121	.d_hash = gfs2_dhash,
b3b94faa DT	122	};
b3b94faa DT	123