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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#include "ctree.h"
15#include "btrfs_inode.h"
16#include "xattr.h"
17#include "acl.h"
18
19struct posix_acl *btrfs_get_acl(struct inode *inode, int type, bool rcu)
20{
21 int size;
22 const char *name;
23 char *value = NULL;
24 struct posix_acl *acl;
25
26 if (rcu)
27 return ERR_PTR(-ECHILD);
28
29 switch (type) {
30 case ACL_TYPE_ACCESS:
31 name = XATTR_NAME_POSIX_ACL_ACCESS;
32 break;
33 case ACL_TYPE_DEFAULT:
34 name = XATTR_NAME_POSIX_ACL_DEFAULT;
35 break;
36 default:
37 return ERR_PTR(-EINVAL);
38 }
39
40 size = btrfs_getxattr(inode, name, NULL, 0);
41 if (size > 0) {
42 value = kzalloc(size, GFP_KERNEL);
43 if (!value)
44 return ERR_PTR(-ENOMEM);
45 size = btrfs_getxattr(inode, name, value, size);
46 }
47 if (size > 0)
48 acl = posix_acl_from_xattr(&init_user_ns, value, size);
49 else if (size == -ENODATA || size == 0)
50 acl = NULL;
51 else
52 acl = ERR_PTR(size);
53 kfree(value);
54
55 return acl;
56}
57
58int __btrfs_set_acl(struct btrfs_trans_handle *trans, struct inode *inode,
59 struct posix_acl *acl, int type)
60{
61 int ret, size = 0;
62 const char *name;
63 char *value = NULL;
64
65 switch (type) {
66 case ACL_TYPE_ACCESS:
67 name = XATTR_NAME_POSIX_ACL_ACCESS;
68 break;
69 case ACL_TYPE_DEFAULT:
70 if (!S_ISDIR(inode->i_mode))
71 return acl ? -EINVAL : 0;
72 name = XATTR_NAME_POSIX_ACL_DEFAULT;
73 break;
74 default:
75 return -EINVAL;
76 }
77
78 if (acl) {
79 unsigned int nofs_flag;
80
81 size = posix_acl_xattr_size(acl->a_count);
82 /*
83 * We're holding a transaction handle, so use a NOFS memory
84 * allocation context to avoid deadlock if reclaim happens.
85 */
86 nofs_flag = memalloc_nofs_save();
87 value = kmalloc(size, GFP_KERNEL);
88 memalloc_nofs_restore(nofs_flag);
89 if (!value) {
90 ret = -ENOMEM;
91 goto out;
92 }
93
94 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
95 if (ret < 0)
96 goto out;
97 }
98
99 if (trans)
100 ret = btrfs_setxattr(trans, inode, name, value, size, 0);
101 else
102 ret = btrfs_setxattr_trans(inode, name, value, size, 0);
103
104out:
105 kfree(value);
106
107 if (!ret)
108 set_cached_acl(inode, type, acl);
109
110 return ret;
111}
112
113int btrfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
114 struct posix_acl *acl, int type)
115{
116 int ret;
117 struct inode *inode = d_inode(dentry);
118 umode_t old_mode = inode->i_mode;
119
120 if (type == ACL_TYPE_ACCESS && acl) {
121 ret = posix_acl_update_mode(idmap, inode,
122 &inode->i_mode, &acl);
123 if (ret)
124 return ret;
125 }
126 ret = __btrfs_set_acl(NULL, inode, acl, type);
127 if (ret)
128 inode->i_mode = old_mode;
129 return ret;
130}
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/slab.h>
13
14#include "ctree.h"
15#include "btrfs_inode.h"
16#include "xattr.h"
17
18struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
19{
20 int size;
21 const char *name;
22 char *value = NULL;
23 struct posix_acl *acl;
24
25 switch (type) {
26 case ACL_TYPE_ACCESS:
27 name = XATTR_NAME_POSIX_ACL_ACCESS;
28 break;
29 case ACL_TYPE_DEFAULT:
30 name = XATTR_NAME_POSIX_ACL_DEFAULT;
31 break;
32 default:
33 BUG();
34 }
35
36 size = btrfs_getxattr(inode, name, "", 0);
37 if (size > 0) {
38 value = kzalloc(size, GFP_KERNEL);
39 if (!value)
40 return ERR_PTR(-ENOMEM);
41 size = btrfs_getxattr(inode, name, value, size);
42 }
43 if (size > 0) {
44 acl = posix_acl_from_xattr(&init_user_ns, value, size);
45 } else if (size == -ERANGE || size == -ENODATA || size == 0) {
46 acl = NULL;
47 } else {
48 acl = ERR_PTR(-EIO);
49 }
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 size = posix_acl_xattr_size(acl->a_count);
77 value = kmalloc(size, GFP_KERNEL);
78 if (!value) {
79 ret = -ENOMEM;
80 goto out;
81 }
82
83 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
84 if (ret < 0)
85 goto out;
86 }
87
88 ret = btrfs_setxattr(trans, inode, name, value, size, 0);
89out:
90 kfree(value);
91
92 if (!ret)
93 set_cached_acl(inode, type, acl);
94
95 return ret;
96}
97
98int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
99{
100 int ret;
101 umode_t old_mode = inode->i_mode;
102
103 if (type == ACL_TYPE_ACCESS && acl) {
104 ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
105 if (ret)
106 return ret;
107 }
108 ret = __btrfs_set_acl(NULL, inode, acl, type);
109 if (ret)
110 inode->i_mode = old_mode;
111 return ret;
112}
113
114int btrfs_init_acl(struct btrfs_trans_handle *trans,
115 struct inode *inode, struct inode *dir)
116{
117 struct posix_acl *default_acl, *acl;
118 int ret = 0;
119
120 /* this happens with subvols */
121 if (!dir)
122 return 0;
123
124 ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
125 if (ret)
126 return ret;
127
128 if (default_acl) {
129 ret = __btrfs_set_acl(trans, inode, default_acl,
130 ACL_TYPE_DEFAULT);
131 posix_acl_release(default_acl);
132 }
133
134 if (acl) {
135 if (!ret)
136 ret = __btrfs_set_acl(trans, inode, acl,
137 ACL_TYPE_ACCESS);
138 posix_acl_release(acl);
139 }
140
141 if (!default_acl && !acl)
142 cache_no_acl(inode);
143 return ret;
144}