xref: /openbmc/linux/fs/orangefs/acl.c (revision 77a87824)
1 /*
2  * (C) 2001 Clemson University and The University of Chicago
3  *
4  * See COPYING in top-level directory.
5  */
6 
7 #include "protocol.h"
8 #include "orangefs-kernel.h"
9 #include "orangefs-bufmap.h"
10 #include <linux/posix_acl_xattr.h>
11 #include <linux/fs_struct.h>
12 
13 struct 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 == NULL)
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 
64 int orangefs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
65 {
66 	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
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 		if (acl) {
76 			umode_t mode = inode->i_mode;
77 			/*
78 			 * can we represent this with the traditional file
79 			 * mode permission bits?
80 			 */
81 			error = posix_acl_equiv_mode(acl, &mode);
82 			if (error < 0) {
83 				gossip_err("%s: posix_acl_equiv_mode err: %d\n",
84 					   __func__,
85 					   error);
86 				return error;
87 			}
88 
89 			if (inode->i_mode != mode)
90 				SetModeFlag(orangefs_inode);
91 			inode->i_mode = mode;
92 			mark_inode_dirty_sync(inode);
93 			if (error == 0)
94 				acl = NULL;
95 		}
96 		break;
97 	case ACL_TYPE_DEFAULT:
98 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
99 		break;
100 	default:
101 		gossip_err("%s: invalid type %d!\n", __func__, type);
102 		return -EINVAL;
103 	}
104 
105 	gossip_debug(GOSSIP_ACL_DEBUG,
106 		     "%s: inode %pU, key %s type %d\n",
107 		     __func__, get_khandle_from_ino(inode),
108 		     name,
109 		     type);
110 
111 	if (acl) {
112 		size = posix_acl_xattr_size(acl->a_count);
113 		value = kmalloc(size, GFP_KERNEL);
114 		if (!value)
115 			return -ENOMEM;
116 
117 		error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
118 		if (error < 0)
119 			goto out;
120 	}
121 
122 	gossip_debug(GOSSIP_ACL_DEBUG,
123 		     "%s: name %s, value %p, size %zd, acl %p\n",
124 		     __func__, name, value, size, acl);
125 	/*
126 	 * Go ahead and set the extended attribute now. NOTE: Suppose acl
127 	 * was NULL, then value will be NULL and size will be 0 and that
128 	 * will xlate to a removexattr. However, we don't want removexattr
129 	 * complain if attributes does not exist.
130 	 */
131 	error = orangefs_inode_setxattr(inode, name, value, size, 0);
132 
133 out:
134 	kfree(value);
135 	if (!error)
136 		set_cached_acl(inode, type, acl);
137 	return error;
138 }
139 
140 int orangefs_init_acl(struct inode *inode, struct inode *dir)
141 {
142 	struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
143 	struct posix_acl *default_acl, *acl;
144 	umode_t mode = inode->i_mode;
145 	int error = 0;
146 
147 	ClearModeFlag(orangefs_inode);
148 
149 	error = posix_acl_create(dir, &mode, &default_acl, &acl);
150 	if (error)
151 		return error;
152 
153 	if (default_acl) {
154 		error = orangefs_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
155 		posix_acl_release(default_acl);
156 	}
157 
158 	if (acl) {
159 		if (!error)
160 			error = orangefs_set_acl(inode, acl, ACL_TYPE_ACCESS);
161 		posix_acl_release(acl);
162 	}
163 
164 	/* If mode of the inode was changed, then do a forcible ->setattr */
165 	if (mode != inode->i_mode) {
166 		SetModeFlag(orangefs_inode);
167 		inode->i_mode = mode;
168 		orangefs_flush_inode(inode);
169 	}
170 
171 	return error;
172 }
173