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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Red Hat. All rights reserved.
4 */
5
6#include <linux/fs.h>
7#include <linux/string.h>
8#include <linux/xattr.h>
9#include <linux/posix_acl_xattr.h>
10#include <linux/posix_acl.h>
11#include <linux/sched.h>
12#include <linux/sched/mm.h>
13#include <linux/slab.h>
14
15#include "ctree.h"
16#include "btrfs_inode.h"
17#include "xattr.h"
18
19struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
20{
21 int size;
22 const char *name;
23 char *value = NULL;
24 struct posix_acl *acl;
25
26 switch (type) {
27 case ACL_TYPE_ACCESS:
28 name = XATTR_NAME_POSIX_ACL_ACCESS;
29 break;
30 case ACL_TYPE_DEFAULT:
31 name = XATTR_NAME_POSIX_ACL_DEFAULT;
32 break;
33 default:
34 return ERR_PTR(-EINVAL);
35 }
36
37 size = btrfs_getxattr(inode, name, NULL, 0);
38 if (size > 0) {
39 value = kzalloc(size, GFP_KERNEL);
40 if (!value)
41 return ERR_PTR(-ENOMEM);
42 size = btrfs_getxattr(inode, name, value, size);
43 }
44 if (size > 0)
45 acl = posix_acl_from_xattr(&init_user_ns, value, size);
46 else if (size == -ENODATA || size == 0)
47 acl = NULL;
48 else
49 acl = ERR_PTR(size);
50 kfree(value);
51
52 return acl;
53}
54
55static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
56 struct inode *inode, struct posix_acl *acl, int type)
57{
58 int ret, size = 0;
59 const char *name;
60 char *value = NULL;
61
62 switch (type) {
63 case ACL_TYPE_ACCESS:
64 name = XATTR_NAME_POSIX_ACL_ACCESS;
65 break;
66 case ACL_TYPE_DEFAULT:
67 if (!S_ISDIR(inode->i_mode))
68 return acl ? -EINVAL : 0;
69 name = XATTR_NAME_POSIX_ACL_DEFAULT;
70 break;
71 default:
72 return -EINVAL;
73 }
74
75 if (acl) {
76 unsigned int nofs_flag;
77
78 size = posix_acl_xattr_size(acl->a_count);
79 /*
80 * We're holding a transaction handle, so use a NOFS memory
81 * allocation context to avoid deadlock if reclaim happens.
82 */
83 nofs_flag = memalloc_nofs_save();
84 value = kmalloc(size, GFP_KERNEL);
85 memalloc_nofs_restore(nofs_flag);
86 if (!value) {
87 ret = -ENOMEM;
88 goto out;
89 }
90
91 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
92 if (ret < 0)
93 goto out;
94 }
95
96 if (trans)
97 ret = btrfs_setxattr(trans, inode, name, value, size, 0);
98 else
99 ret = btrfs_setxattr_trans(inode, name, value, size, 0);
100
101out:
102 kfree(value);
103
104 if (!ret)
105 set_cached_acl(inode, type, acl);
106
107 return ret;
108}
109
110int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
111{
112 int ret;
113 umode_t old_mode = inode->i_mode;
114
115 if (type == ACL_TYPE_ACCESS && acl) {
116 ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
117 if (ret)
118 return ret;
119 }
120 ret = __btrfs_set_acl(NULL, inode, acl, type);
121 if (ret)
122 inode->i_mode = old_mode;
123 return ret;
124}
125
126int btrfs_init_acl(struct btrfs_trans_handle *trans,
127 struct inode *inode, struct inode *dir)
128{
129 struct posix_acl *default_acl, *acl;
130 int ret = 0;
131
132 /* this happens with subvols */
133 if (!dir)
134 return 0;
135
136 ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
137 if (ret)
138 return ret;
139
140 if (default_acl) {
141 ret = __btrfs_set_acl(trans, inode, default_acl,
142 ACL_TYPE_DEFAULT);
143 posix_acl_release(default_acl);
144 }
145
146 if (acl) {
147 if (!ret)
148 ret = __btrfs_set_acl(trans, inode, acl,
149 ACL_TYPE_ACCESS);
150 posix_acl_release(acl);
151 }
152
153 if (!default_acl && !acl)
154 cache_no_acl(inode);
155 return ret;
156}
1/*
2 * Copyright (C) 2007 Red Hat. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/fs.h>
20#include <linux/string.h>
21#include <linux/xattr.h>
22#include <linux/posix_acl_xattr.h>
23#include <linux/posix_acl.h>
24#include <linux/sched.h>
25#include <linux/slab.h>
26
27#include "ctree.h"
28#include "btrfs_inode.h"
29#include "xattr.h"
30
31struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
32{
33 int size;
34 const char *name;
35 char *value = NULL;
36 struct posix_acl *acl;
37
38 switch (type) {
39 case ACL_TYPE_ACCESS:
40 name = XATTR_NAME_POSIX_ACL_ACCESS;
41 break;
42 case ACL_TYPE_DEFAULT:
43 name = XATTR_NAME_POSIX_ACL_DEFAULT;
44 break;
45 default:
46 BUG();
47 }
48
49 size = __btrfs_getxattr(inode, name, "", 0);
50 if (size > 0) {
51 value = kzalloc(size, GFP_KERNEL);
52 if (!value)
53 return ERR_PTR(-ENOMEM);
54 size = __btrfs_getxattr(inode, name, value, size);
55 }
56 if (size > 0) {
57 acl = posix_acl_from_xattr(&init_user_ns, value, size);
58 } else if (size == -ENOENT || size == -ENODATA || size == 0) {
59 /* FIXME, who returns -ENOENT? I think nobody */
60 acl = NULL;
61 } else {
62 acl = ERR_PTR(-EIO);
63 }
64 kfree(value);
65
66 if (!IS_ERR(acl))
67 set_cached_acl(inode, type, acl);
68
69 return acl;
70}
71
72/*
73 * Needs to be called with fs_mutex held
74 */
75static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
76 struct inode *inode, struct posix_acl *acl, int type)
77{
78 int ret, size = 0;
79 const char *name;
80 char *value = NULL;
81
82 switch (type) {
83 case ACL_TYPE_ACCESS:
84 name = XATTR_NAME_POSIX_ACL_ACCESS;
85 if (acl) {
86 ret = posix_acl_equiv_mode(acl, &inode->i_mode);
87 if (ret < 0)
88 return ret;
89 if (ret == 0)
90 acl = NULL;
91 }
92 ret = 0;
93 break;
94 case ACL_TYPE_DEFAULT:
95 if (!S_ISDIR(inode->i_mode))
96 return acl ? -EINVAL : 0;
97 name = XATTR_NAME_POSIX_ACL_DEFAULT;
98 break;
99 default:
100 return -EINVAL;
101 }
102
103 if (acl) {
104 size = posix_acl_xattr_size(acl->a_count);
105 value = kmalloc(size, GFP_KERNEL);
106 if (!value) {
107 ret = -ENOMEM;
108 goto out;
109 }
110
111 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
112 if (ret < 0)
113 goto out;
114 }
115
116 ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
117out:
118 kfree(value);
119
120 if (!ret)
121 set_cached_acl(inode, type, acl);
122
123 return ret;
124}
125
126int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
127{
128 return __btrfs_set_acl(NULL, inode, acl, type);
129}
130
131/*
132 * btrfs_init_acl is already generally called under fs_mutex, so the locking
133 * stuff has been fixed to work with that. If the locking stuff changes, we
134 * need to re-evaluate the acl locking stuff.
135 */
136int btrfs_init_acl(struct btrfs_trans_handle *trans,
137 struct inode *inode, struct inode *dir)
138{
139 struct posix_acl *default_acl, *acl;
140 int ret = 0;
141
142 /* this happens with subvols */
143 if (!dir)
144 return 0;
145
146 ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
147 if (ret)
148 return ret;
149
150 if (default_acl) {
151 ret = __btrfs_set_acl(trans, inode, default_acl,
152 ACL_TYPE_DEFAULT);
153 posix_acl_release(default_acl);
154 }
155
156 if (acl) {
157 if (!ret)
158 ret = __btrfs_set_acl(trans, inode, acl,
159 ACL_TYPE_ACCESS);
160 posix_acl_release(acl);
161 }
162
163 if (!default_acl && !acl)
164 cache_no_acl(inode);
165 return ret;
166}