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
btrfs_get_acl(struct inode * inode,int type)18 struct 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 return ERR_PTR(-EINVAL);
34 }
35
36 size = btrfs_getxattr(inode, name, NULL, 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 == -ENODATA || size == 0)
46 acl = NULL;
47 else
48 acl = ERR_PTR(size);
49 kfree(value);
50
51 return acl;
52 }
53
__btrfs_set_acl(struct btrfs_trans_handle * trans,struct inode * inode,struct posix_acl * acl,int type)54 static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
55 struct inode *inode, struct posix_acl *acl, int type)
56 {
57 int ret, size = 0;
58 const char *name;
59 char *value = NULL;
60
61 switch (type) {
62 case ACL_TYPE_ACCESS:
63 name = XATTR_NAME_POSIX_ACL_ACCESS;
64 break;
65 case ACL_TYPE_DEFAULT:
66 if (!S_ISDIR(inode->i_mode))
67 return acl ? -EINVAL : 0;
68 name = XATTR_NAME_POSIX_ACL_DEFAULT;
69 break;
70 default:
71 return -EINVAL;
72 }
73
74 if (acl) {
75 size = posix_acl_xattr_size(acl->a_count);
76 value = kmalloc(size, GFP_KERNEL);
77 if (!value) {
78 ret = -ENOMEM;
79 goto out;
80 }
81
82 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
83 if (ret < 0)
84 goto out;
85 }
86
87 ret = btrfs_setxattr(trans, inode, name, value, size, 0);
88 out:
89 kfree(value);
90
91 if (!ret)
92 set_cached_acl(inode, type, acl);
93
94 return ret;
95 }
96
btrfs_set_acl(struct inode * inode,struct posix_acl * acl,int type)97 int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
98 {
99 int ret;
100 umode_t old_mode = inode->i_mode;
101
102 if (type == ACL_TYPE_ACCESS && acl) {
103 ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
104 if (ret)
105 return ret;
106 }
107 ret = __btrfs_set_acl(NULL, inode, acl, type);
108 if (ret)
109 inode->i_mode = old_mode;
110 return ret;
111 }
112
btrfs_init_acl(struct btrfs_trans_handle * trans,struct inode * inode,struct inode * dir)113 int btrfs_init_acl(struct btrfs_trans_handle *trans,
114 struct inode *inode, struct inode *dir)
115 {
116 struct posix_acl *default_acl, *acl;
117 int ret = 0;
118
119 /* this happens with subvols */
120 if (!dir)
121 return 0;
122
123 ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
124 if (ret)
125 return ret;
126
127 if (default_acl) {
128 ret = __btrfs_set_acl(trans, inode, default_acl,
129 ACL_TYPE_DEFAULT);
130 posix_acl_release(default_acl);
131 }
132
133 if (acl) {
134 if (!ret)
135 ret = __btrfs_set_acl(trans, inode, acl,
136 ACL_TYPE_ACCESS);
137 posix_acl_release(acl);
138 }
139
140 if (!default_acl && !acl)
141 cache_no_acl(inode);
142 return ret;
143 }
144
