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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/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}