1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
5 */
6
7#include <linux/spinlock.h>
8#include <linux/completion.h>
9#include <linux/buffer_head.h>
10#include <linux/gfs2_ondisk.h>
11#include <linux/namei.h>
12#include <linux/crc32.h>
13
14#include "gfs2.h"
15#include "incore.h"
16#include "dir.h"
17#include "glock.h"
18#include "super.h"
19#include "util.h"
20#include "inode.h"
21
22/**
23 * gfs2_drevalidate - Check directory lookup consistency
24 * @dentry: the mapping to check
25 * @flags: lookup flags
26 *
27 * Check to make sure the lookup necessary to arrive at this inode from its
28 * parent is still good.
29 *
30 * Returns: 1 if the dentry is ok, 0 if it isn't
31 */
32
33static int gfs2_drevalidate(struct dentry *dentry, unsigned int flags)
34{
35	struct dentry *parent;
36	struct gfs2_sbd *sdp;
37	struct gfs2_inode *dip;
38	struct inode *inode;
39	struct gfs2_holder d_gh;
40	struct gfs2_inode *ip = NULL;
41	int error, valid = 0;
42	int had_lock = 0;
43
44	if (flags & LOOKUP_RCU)
45		return -ECHILD;
46
47	parent = dget_parent(dentry);
48	sdp = GFS2_SB(d_inode(parent));
49	dip = GFS2_I(d_inode(parent));
50	inode = d_inode(dentry);
51
52	if (inode) {
53		if (is_bad_inode(inode))
54			goto out;
55		ip = GFS2_I(inode);
56	}
57
58	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL) {
59		valid = 1;
60		goto out;
61	}
62
63	had_lock = (gfs2_glock_is_locked_by_me(dip->i_gl) != NULL);
64	if (!had_lock) {
65		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
66		if (error)
67			goto out;
68	}
69
70	error = gfs2_dir_check(d_inode(parent), &dentry->d_name, ip);
71	valid = inode ? !error : (error == -ENOENT);
72
73	if (!had_lock)
74		gfs2_glock_dq_uninit(&d_gh);
75out:
76	dput(parent);
77	return valid;
78}
79
80static int gfs2_dhash(const struct dentry *dentry, struct qstr *str)
81{
82	str->hash = gfs2_disk_hash(str->name, str->len);
83	return 0;
84}
85
86static int gfs2_dentry_delete(const struct dentry *dentry)
87{
88	struct gfs2_inode *ginode;
89
90	if (d_really_is_negative(dentry))
91		return 0;
92
93	ginode = GFS2_I(d_inode(dentry));
94	if (!gfs2_holder_initialized(&ginode->i_iopen_gh))
95		return 0;
96
97	if (test_bit(GLF_DEMOTE, &ginode->i_iopen_gh.gh_gl->gl_flags))
98		return 1;
99
100	return 0;
101}
102
103const struct dentry_operations gfs2_dops = {
104	.d_revalidate = gfs2_drevalidate,
105	.d_hash = gfs2_dhash,
106	.d_delete = gfs2_dentry_delete,
107};
108
109