xref: /openbmc/linux/fs/orangefs/acl.c (revision e3b9f1e8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * (C) 2001 Clemson University and The University of Chicago
4  *
5  * See COPYING in top-level directory.
6  */
7 
8 #include "protocol.h"
9 #include "orangefs-kernel.h"
10 #include "orangefs-bufmap.h"
11 #include <linux/posix_acl_xattr.h>
12 #include <linux/fs_struct.h>
13 
14 struct posix_acl *orangefs_get_acl(struct inode *inode, int type)
15 {
16 	struct posix_acl *acl;
17 	int ret;
18 	char *key = NULL, *value = NULL;
19 
20 	switch (type) {
21 	case ACL_TYPE_ACCESS:
22 		key = XATTR_NAME_POSIX_ACL_ACCESS;
23 		break;
24 	case ACL_TYPE_DEFAULT:
25 		key = XATTR_NAME_POSIX_ACL_DEFAULT;
26 		break;
27 	default:
28 		gossip_err("orangefs_get_acl: bogus value of type %d\n", type);
29 		return ERR_PTR(-EINVAL);
30 	}
31 	/*
32 	 * Rather than incurring a network call just to determine the exact
33 	 * length of the attribute, I just allocate a max length to save on
34 	 * the network call. Conceivably, we could pass NULL to
35 	 * orangefs_inode_getxattr() to probe the length of the value, but
36 	 * I don't do that for now.
37 	 */
38 	value = kmalloc(ORANGEFS_MAX_XATTR_VALUELEN, GFP_KERNEL);
39 	if (!value)
40 		return ERR_PTR(-ENOMEM);
41 
42 	gossip_debug(GOSSIP_ACL_DEBUG,
43 		     "inode %pU, key %s, type %d\n",
44 		     get_khandle_from_ino(inode),
45 		     key,
46 		     type);
47 	ret = orangefs_inode_getxattr(inode, key, value,
48 				      ORANGEFS_MAX_XATTR_VALUELEN);
49 	/* if the key exists, convert it to an in-memory rep */
50 	if (ret > 0) {
51 		acl = posix_acl_from_xattr(&init_user_ns, value, ret);
52 	} else if (ret == -ENODATA || ret == -ENOSYS) {
53 		acl = NULL;
54 	} else {
55 		gossip_err("inode %pU retrieving acl's failed with error %d\n",
56 			   get_khandle_from_ino(inode),
57 			   ret);
58 		acl = ERR_PTR(ret);
59 	}
60 	/* kfree(NULL) is safe, so don't worry if value ever got used */
61 	kfree(value);
62 	return acl;
63 }
64 
65 static int __orangefs_set_acl(struct inode *inode, struct posix_acl *acl,
66 			      int type)
67 {
68 	int error = 0;
69 	void *value = NULL;
70 	size_t size = 0;
71 	const char *name = NULL;
72 
73 	switch (type) {
74 	case ACL_TYPE_ACCESS:
75 		name = XATTR_NAME_POSIX_ACL_ACCESS;
76 		break;
77 	case ACL_TYPE_DEFAULT:
78 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
79 		break;
80 	default:
81 		gossip_err("%s: invalid type %d!\n", __func__, type);
82 		return -EINVAL;
83 	}
84 
85 	gossip_debug(GOSSIP_ACL_DEBUG,
86 		     "%s: inode %pU, key %s type %d\n",
87 		     __func__, get_khandle_from_ino(inode),
88 		     name,
89 		     type);
90 
91 	if (acl) {
92 		size = posix_acl_xattr_size(acl->a_count);
93 		value = kmalloc(size, GFP_KERNEL);
94 		if (!value)
95 			return -ENOMEM;
96 
97 		error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
98 		if (error < 0)
99 			goto out;
100 	}
101 
102 	gossip_debug(GOSSIP_ACL_DEBUG,
103 		     "%s: name %s, value %p, size %zd, acl %p\n",
104 		     __func__, name, value, size, acl);
105 	/*
106 	 * Go ahead and set the extended attribute now. NOTE: Suppose acl
107 	 * was NULL, then value will be NULL and size will be 0 and that
108 	 * will xlate to a removexattr. However, we don't want removexattr
109 	 * complain if attributes does not exist.
110 	 */
111 	error = orangefs_inode_setxattr(inode, name, value, size, 0);
112 
113 out:
114 	kfree(value);
115 	if (!error)
116 		set_cached_acl(inode, type, acl);
117 	return error;
118 }
119 
120 int orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
121 {
122 	int error;
123 	struct iattr iattr;
124 	int rc;
125 
126 	if (type == ACL_TYPE_ACCESS && acl) {
127 		/*
128 		 * posix_acl_update_mode checks to see if the permissions
129 		 * described by the ACL can be encoded into the
130 		 * object's mode. If so, it sets "acl" to NULL
131 		 * and "mode" to the new desired value. It is up to
132 		 * us to propagate the new mode back to the server...
133 		 */
134 		error = posix_acl_update_mode(inode, &iattr.ia_mode, &acl);
135 		if (error) {
136 			gossip_err("%s: posix_acl_update_mode err: %d\n",
137 				   __func__,
138 				   error);
139 			return error;
140 		}
141 
142 		if (acl) {
143 			rc = __orangefs_set_acl(inode, acl, type);
144 		} else {
145 			iattr.ia_valid = ATTR_MODE;
146 			rc = orangefs_inode_setattr(inode, &iattr);
147 		}
148 
149 		return rc;
150 
151 	} else {
152 		return -EINVAL;
153 	}
154 }
155 
156 int orangefs_init_acl(struct inode *inode, struct inode *dir)
157 {
158 	struct posix_acl *default_acl, *acl;
159 	umode_t mode = inode->i_mode;
160 	struct iattr iattr;
161 	int error = 0;
162 
163 	error = posix_acl_create(dir, &mode, &default_acl, &acl);
164 	if (error)
165 		return error;
166 
167 	if (default_acl) {
168 		error = __orangefs_set_acl(inode, default_acl,
169 					   ACL_TYPE_DEFAULT);
170 		posix_acl_release(default_acl);
171 	}
172 
173 	if (acl) {
174 		if (!error)
175 			error = __orangefs_set_acl(inode, acl, ACL_TYPE_ACCESS);
176 		posix_acl_release(acl);
177 	}
178 
179 	/* If mode of the inode was changed, then do a forcible ->setattr */
180 	if (mode != inode->i_mode) {
181 		memset(&iattr, 0, sizeof iattr);
182 		inode->i_mode = mode;
183 		iattr.ia_mode = mode;
184 		iattr.ia_valid |= ATTR_MODE;
185 		orangefs_inode_setattr(inode, &iattr);
186 	}
187 
188 	return error;
189 }
190