summaryrefslogtreecommitdiff
path: root/fs/gfs2/dentry.c
blob: a7bb76e9a82b111e1c6870082fe3ffd7ab3bef3b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 */

#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 (!gfs2_holder_initialized(&ginode->i_iopen_gh))
		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,
};