xref: /kernel/linux/linux-5.10/fs/orangefs/acl.c (revision 8c2ecf20)
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
13struct posix_acl *orangefs_get_acl(struct inode *inode, int type)
14{
15	struct posix_acl *acl;
16	int ret;
17	char *key = NULL, *value = NULL;
18
19	switch (type) {
20	case ACL_TYPE_ACCESS:
21		key = XATTR_NAME_POSIX_ACL_ACCESS;
22		break;
23	case ACL_TYPE_DEFAULT:
24		key = XATTR_NAME_POSIX_ACL_DEFAULT;
25		break;
26	default:
27		gossip_err("orangefs_get_acl: bogus value of type %d\n", type);
28		return ERR_PTR(-EINVAL);
29	}
30	/*
31	 * Rather than incurring a network call just to determine the exact
32	 * length of the attribute, I just allocate a max length to save on
33	 * the network call. Conceivably, we could pass NULL to
34	 * orangefs_inode_getxattr() to probe the length of the value, but
35	 * I don't do that for now.
36	 */
37	value = kmalloc(ORANGEFS_MAX_XATTR_VALUELEN, GFP_KERNEL);
38	if (!value)
39		return ERR_PTR(-ENOMEM);
40
41	gossip_debug(GOSSIP_ACL_DEBUG,
42		     "inode %pU, key %s, type %d\n",
43		     get_khandle_from_ino(inode),
44		     key,
45		     type);
46	ret = orangefs_inode_getxattr(inode, key, value,
47				      ORANGEFS_MAX_XATTR_VALUELEN);
48	/* if the key exists, convert it to an in-memory rep */
49	if (ret > 0) {
50		acl = posix_acl_from_xattr(&init_user_ns, value, ret);
51	} else if (ret == -ENODATA || ret == -ENOSYS) {
52		acl = NULL;
53	} else {
54		gossip_err("inode %pU retrieving acl's failed with error %d\n",
55			   get_khandle_from_ino(inode),
56			   ret);
57		acl = ERR_PTR(ret);
58	}
59	/* kfree(NULL) is safe, so don't worry if value ever got used */
60	kfree(value);
61	return acl;
62}
63
64static int __orangefs_set_acl(struct inode *inode, struct posix_acl *acl,
65			      int type)
66{
67	int error = 0;
68	void *value = NULL;
69	size_t size = 0;
70	const char *name = NULL;
71
72	switch (type) {
73	case ACL_TYPE_ACCESS:
74		name = XATTR_NAME_POSIX_ACL_ACCESS;
75		break;
76	case ACL_TYPE_DEFAULT:
77		name = XATTR_NAME_POSIX_ACL_DEFAULT;
78		break;
79	default:
80		gossip_err("%s: invalid type %d!\n", __func__, type);
81		return -EINVAL;
82	}
83
84	gossip_debug(GOSSIP_ACL_DEBUG,
85		     "%s: inode %pU, key %s type %d\n",
86		     __func__, get_khandle_from_ino(inode),
87		     name,
88		     type);
89
90	if (acl) {
91		size = posix_acl_xattr_size(acl->a_count);
92		value = kmalloc(size, GFP_KERNEL);
93		if (!value)
94			return -ENOMEM;
95
96		error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
97		if (error < 0)
98			goto out;
99	}
100
101	gossip_debug(GOSSIP_ACL_DEBUG,
102		     "%s: name %s, value %p, size %zd, acl %p\n",
103		     __func__, name, value, size, acl);
104	/*
105	 * Go ahead and set the extended attribute now. NOTE: Suppose acl
106	 * was NULL, then value will be NULL and size will be 0 and that
107	 * will xlate to a removexattr. However, we don't want removexattr
108	 * complain if attributes does not exist.
109	 */
110	error = orangefs_inode_setxattr(inode, name, value, size, 0);
111
112out:
113	kfree(value);
114	if (!error)
115		set_cached_acl(inode, type, acl);
116	return error;
117}
118
119int orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
120{
121	int error;
122	struct iattr iattr;
123	int rc;
124
125	memset(&iattr, 0, sizeof iattr);
126
127	if (type == ACL_TYPE_ACCESS && acl) {
128		/*
129		 * posix_acl_update_mode checks to see if the permissions
130		 * described by the ACL can be encoded into the
131		 * object's mode. If so, it sets "acl" to NULL
132		 * and "mode" to the new desired value. It is up to
133		 * us to propagate the new mode back to the server...
134		 */
135		error = posix_acl_update_mode(inode, &iattr.ia_mode, &acl);
136		if (error) {
137			gossip_err("%s: posix_acl_update_mode err: %d\n",
138				   __func__,
139				   error);
140			return error;
141		}
142
143		if (inode->i_mode != iattr.ia_mode)
144			iattr.ia_valid = ATTR_MODE;
145
146	}
147
148	rc = __orangefs_set_acl(inode, acl, type);
149
150	if (!rc && (iattr.ia_valid == ATTR_MODE))
151		rc = __orangefs_setattr(inode, &iattr);
152
153	return rc;
154}
155
156int 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	} else {
172		inode->i_default_acl = NULL;
173	}
174
175	if (acl) {
176		if (!error)
177			error = __orangefs_set_acl(inode, acl, ACL_TYPE_ACCESS);
178		posix_acl_release(acl);
179	} else {
180		inode->i_acl = NULL;
181	}
182
183	/* If mode of the inode was changed, then do a forcible ->setattr */
184	if (mode != inode->i_mode) {
185		memset(&iattr, 0, sizeof iattr);
186		inode->i_mode = mode;
187		iattr.ia_mode = mode;
188		iattr.ia_valid |= ATTR_MODE;
189		__orangefs_setattr(inode, &iattr);
190	}
191
192	return error;
193}
194