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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 == -ERANGE || size == -ENODATA || size == 0) {
59 acl = NULL;
60 } else {
61 acl = ERR_PTR(-EIO);
62 }
63 kfree(value);
64
65 return acl;
66}
67
68/*
69 * Needs to be called with fs_mutex held
70 */
71static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
72 struct inode *inode, struct posix_acl *acl, int type)
73{
74 int ret, size = 0;
75 const char *name;
76 char *value = NULL;
77
78 switch (type) {
79 case ACL_TYPE_ACCESS:
80 name = XATTR_NAME_POSIX_ACL_ACCESS;
81 if (acl) {
82 ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
83 if (ret)
84 return ret;
85 }
86 ret = 0;
87 break;
88 case ACL_TYPE_DEFAULT:
89 if (!S_ISDIR(inode->i_mode))
90 return acl ? -EINVAL : 0;
91 name = XATTR_NAME_POSIX_ACL_DEFAULT;
92 break;
93 default:
94 return -EINVAL;
95 }
96
97 if (acl) {
98 size = posix_acl_xattr_size(acl->a_count);
99 value = kmalloc(size, GFP_KERNEL);
100 if (!value) {
101 ret = -ENOMEM;
102 goto out;
103 }
104
105 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
106 if (ret < 0)
107 goto out;
108 }
109
110 ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
111out:
112 kfree(value);
113
114 if (!ret)
115 set_cached_acl(inode, type, acl);
116
117 return ret;
118}
119
120int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
121{
122 return __btrfs_set_acl(NULL, inode, acl, type);
123}
124
125/*
126 * btrfs_init_acl is already generally called under fs_mutex, so the locking
127 * stuff has been fixed to work with that. If the locking stuff changes, we
128 * need to re-evaluate the acl locking stuff.
129 */
130int btrfs_init_acl(struct btrfs_trans_handle *trans,
131 struct inode *inode, struct inode *dir)
132{
133 struct posix_acl *default_acl, *acl;
134 int ret = 0;
135
136 /* this happens with subvols */
137 if (!dir)
138 return 0;
139
140 ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
141 if (ret)
142 return ret;
143
144 if (default_acl) {
145 ret = __btrfs_set_acl(trans, inode, default_acl,
146 ACL_TYPE_DEFAULT);
147 posix_acl_release(default_acl);
148 }
149
150 if (acl) {
151 if (!ret)
152 ret = __btrfs_set_acl(trans, inode, acl,
153 ACL_TYPE_ACCESS);
154 posix_acl_release(acl);
155 }
156
157 if (!default_acl && !acl)
158 cache_no_acl(inode);
159 return ret;
160}