[deliverable/linux.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 version 2.
 */

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.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
 * @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 = GFS2_SB(parent->d_inode);
	struct gfs2_inode *dip = GFS2_I(parent->d_inode);
	struct inode *inode = dentry->d_inode;
	struct gfs2_holder d_gh;
	struct gfs2_inode *ip = NULL;
	int error;
	int had_lock = 0;

	if (inode) {
		if (is_bad_inode(inode))
			goto invalid;
		ip = GFS2_I(inode);
	}

	if (sdp->sd_args.ar_localcaching)
		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(parent->d_inode, &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:
	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;
}

const 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
e9fc2aa0	7	* of the GNU General Public License version 2.
b3b94faa DT	8	*/
b3b94faa DT	9
b3b94faa DT	10	#include <linux/slab.h>
	11	#include <linux/spinlock.h>
	12	#include <linux/completion.h>
	13	#include <linux/buffer_head.h>
5c676f6d	14	#include <linux/gfs2_ondisk.h>
71b86f56	15	#include <linux/crc32.h>
b3b94faa DT	16
b3b94faa DT	17	#include "gfs2.h"
5c676f6d	18	#include "incore.h"
b3b94faa DT	19	#include "dir.h"
b3b94faa DT	20	#include "glock.h"
b2760583	21	#include "super.h"
5c676f6d	22	#include "util.h"
dbb7cae2	23	#include "inode.h"
b3b94faa DT	24
	25	/**
	26	* gfs2_drevalidate - Check directory lookup consistency
	27	* @dentry: the mapping to check
	28	* @nd:
	29	*
	30	* Check to make sure the lookup necessary to arrive at this inode from its
	31	* parent is still good.
	32	*
	33	* Returns: 1 if the dentry is ok, 0 if it isn't
	34	*/
	35
	36	static int gfs2_drevalidate(struct dentry dentry, struct nameidata nd)
	37	{
	38	struct dentry *parent = dget_parent(dentry);
feaa7bba SW	39	struct gfs2_sbd *sdp = GFS2_SB(parent->d_inode);
feaa7bba SW	40	struct gfs2_inode *dip = GFS2_I(parent->d_inode);
c752666c	41	struct inode *inode = dentry->d_inode;
b3b94faa	42	struct gfs2_holder d_gh;
dbb7cae2	43	struct gfs2_inode *ip = NULL;
b3b94faa	44	int error;
7afd88d9	45	int had_lock = 0;
b3b94faa	46
dbb7cae2 SW	47	if (inode) {
	48	if (is_bad_inode(inode))
	49	goto invalid;
	50	ip = GFS2_I(inode);
	51	}
b3b94faa	52
c752666c SW	53	if (sdp->sd_args.ar_localcaching)
	54	goto valid;
	55
7afd88d9	56	had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
549ae0ac WC	57	if (!had_lock) {
	58	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
	59	if (error)
	60	goto fail;
	61	}
b3b94faa	62
dbb7cae2	63	error = gfs2_dir_check(parent->d_inode, &dentry->d_name, ip);
b3b94faa DT	64	switch (error) {
	65	case 0:
	66	if (!inode)
	67	goto invalid_gunlock;
	68	break;
	69	case -ENOENT:
	70	if (!inode)
	71	goto valid_gunlock;
	72	goto invalid_gunlock;
	73	default:
	74	goto fail_gunlock;
	75	}
	76
a91ea69f	77	valid_gunlock:
549ae0ac WC	78	if (!had_lock)
549ae0ac WC	79	gfs2_glock_dq_uninit(&d_gh);
a91ea69f	80	valid:
b3b94faa DT	81	dput(parent);
	82	return 1;
	83
a91ea69f	84	invalid_gunlock:
549ae0ac WC	85	if (!had_lock)
549ae0ac WC	86	gfs2_glock_dq_uninit(&d_gh);
a91ea69f	87	invalid:
b3b94faa DT	88	if (inode && S_ISDIR(inode->i_mode)) {
	89	if (have_submounts(dentry))
	90	goto valid;
	91	shrink_dcache_parent(dentry);
	92	}
	93	d_drop(dentry);
b3b94faa DT	94	dput(parent);
	95	return 0;
	96
a91ea69f	97	fail_gunlock:
b3b94faa	98	gfs2_glock_dq_uninit(&d_gh);
a91ea69f	99	fail:
b3b94faa DT	100	dput(parent);
	101	return 0;
	102	}
	103
c752666c SW	104	static int gfs2_dhash(struct dentry dentry, struct qstr str)
	105	{
	106	str->hash = gfs2_disk_hash(str->name, str->len);
	107	return 0;
	108	}
	109
92cecbbf	110	const struct dentry_operations gfs2_dops = {
b3b94faa	111	.d_revalidate = gfs2_drevalidate,
c752666c	112	.d_hash = gfs2_dhash,
b3b94faa DT	113	};
b3b94faa DT	114