summaryrefslogtreecommitdiffstats
path: root/fs/gfs2/acl.c
blob: e2a79d7e5605fb1d07f4e396c9134eb376a03292 (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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
// 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/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/gfs2_ondisk.h>

#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "xattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"

static const char *gfs2_acl_name(int type)
{
	switch (type) {
	case ACL_TYPE_ACCESS:
		return XATTR_POSIX_ACL_ACCESS;
	case ACL_TYPE_DEFAULT:
		return XATTR_POSIX_ACL_DEFAULT;
	}
	return NULL;
}

static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct posix_acl *acl;
	const char *name;
	char *data;
	int len;

	if (!ip->i_eattr)
		return NULL;

	name = gfs2_acl_name(type);
	len = gfs2_xattr_acl_get(ip, name, &data);
	if (len <= 0)
		return ERR_PTR(len);
	acl = posix_acl_from_xattr(&init_user_ns, data, len);
	kfree(data);
	return acl;
}

struct posix_acl *gfs2_get_acl(struct inode *inode, int type, bool rcu)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder gh;
	bool need_unlock = false;
	struct posix_acl *acl;

	if (rcu)
		return ERR_PTR(-ECHILD);

	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
		int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
					     LM_FLAG_ANY, &gh);
		if (ret)
			return ERR_PTR(ret);
		need_unlock = true;
	}
	acl = __gfs2_get_acl(inode, type);
	if (need_unlock)
		gfs2_glock_dq_uninit(&gh);
	return acl;
}

int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
{
	int error;
	size_t len;
	char *data;
	const char *name = gfs2_acl_name(type);

	if (acl) {
		len = posix_acl_xattr_size(acl->a_count);
		data = kmalloc(len, GFP_NOFS);
		if (data == NULL)
			return -ENOMEM;
		error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
		if (error < 0)
			goto out;
	} else {
		data = NULL;
		len = 0;
	}

	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
	if (error)
		goto out;
	set_cached_acl(inode, type, acl);
out:
	kfree(data);
	return error;
}

int gfs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
		 struct posix_acl *acl, int type)
{
	struct inode *inode = d_inode(dentry);
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder gh;
	bool need_unlock = false;
	int ret;
	umode_t mode;

	if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
		return -E2BIG;

	ret = gfs2_qa_get(ip);
	if (ret)
		return ret;

	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
		if (ret)
			goto out;
		need_unlock = true;
	}

	mode = inode->i_mode;
	if (type == ACL_TYPE_ACCESS && acl) {
		ret = posix_acl_update_mode(&init_user_ns, inode, &mode, &acl);
		if (ret)
			goto unlock;
	}

	ret = __gfs2_set_acl(inode, acl, type);
	if (!ret && mode != inode->i_mode) {
		inode->i_ctime = current_time(inode);
		inode->i_mode = mode;
		mark_inode_dirty(inode);
	}
unlock:
	if (need_unlock)
		gfs2_glock_dq_uninit(&gh);
out:
	gfs2_qa_put(ip);
	return ret;
}