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7#include <linux/quotaops.h>
8#include "ext4_jbd2.h"
9#include "ext4.h"
10#include "xattr.h"
11#include "acl.h"
12
13
14
15
16static struct posix_acl *
17ext4_acl_from_disk(const void *value, size_t size)
18{
19 const char *end = (char *)value + size;
20 int n, count;
21 struct posix_acl *acl;
22
23 if (!value)
24 return NULL;
25 if (size < sizeof(ext4_acl_header))
26 return ERR_PTR(-EINVAL);
27 if (((ext4_acl_header *)value)->a_version !=
28 cpu_to_le32(EXT4_ACL_VERSION))
29 return ERR_PTR(-EINVAL);
30 value = (char *)value + sizeof(ext4_acl_header);
31 count = ext4_acl_count(size);
32 if (count < 0)
33 return ERR_PTR(-EINVAL);
34 if (count == 0)
35 return NULL;
36 acl = posix_acl_alloc(count, GFP_NOFS);
37 if (!acl)
38 return ERR_PTR(-ENOMEM);
39 for (n = 0; n < count; n++) {
40 ext4_acl_entry *entry =
41 (ext4_acl_entry *)value;
42 if ((char *)value + sizeof(ext4_acl_entry_short) > end)
43 goto fail;
44 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
45 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
46
47 switch (acl->a_entries[n].e_tag) {
48 case ACL_USER_OBJ:
49 case ACL_GROUP_OBJ:
50 case ACL_MASK:
51 case ACL_OTHER:
52 value = (char *)value +
53 sizeof(ext4_acl_entry_short);
54 break;
55
56 case ACL_USER:
57 value = (char *)value + sizeof(ext4_acl_entry);
58 if ((char *)value > end)
59 goto fail;
60 acl->a_entries[n].e_uid =
61 make_kuid(&init_user_ns,
62 le32_to_cpu(entry->e_id));
63 break;
64 case ACL_GROUP:
65 value = (char *)value + sizeof(ext4_acl_entry);
66 if ((char *)value > end)
67 goto fail;
68 acl->a_entries[n].e_gid =
69 make_kgid(&init_user_ns,
70 le32_to_cpu(entry->e_id));
71 break;
72
73 default:
74 goto fail;
75 }
76 }
77 if (value != end)
78 goto fail;
79 return acl;
80
81fail:
82 posix_acl_release(acl);
83 return ERR_PTR(-EINVAL);
84}
85
86
87
88
89static void *
90ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
91{
92 ext4_acl_header *ext_acl;
93 char *e;
94 size_t n;
95
96 *size = ext4_acl_size(acl->a_count);
97 ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
98 sizeof(ext4_acl_entry), GFP_NOFS);
99 if (!ext_acl)
100 return ERR_PTR(-ENOMEM);
101 ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
102 e = (char *)ext_acl + sizeof(ext4_acl_header);
103 for (n = 0; n < acl->a_count; n++) {
104 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
105 ext4_acl_entry *entry = (ext4_acl_entry *)e;
106 entry->e_tag = cpu_to_le16(acl_e->e_tag);
107 entry->e_perm = cpu_to_le16(acl_e->e_perm);
108 switch (acl_e->e_tag) {
109 case ACL_USER:
110 entry->e_id = cpu_to_le32(
111 from_kuid(&init_user_ns, acl_e->e_uid));
112 e += sizeof(ext4_acl_entry);
113 break;
114 case ACL_GROUP:
115 entry->e_id = cpu_to_le32(
116 from_kgid(&init_user_ns, acl_e->e_gid));
117 e += sizeof(ext4_acl_entry);
118 break;
119
120 case ACL_USER_OBJ:
121 case ACL_GROUP_OBJ:
122 case ACL_MASK:
123 case ACL_OTHER:
124 e += sizeof(ext4_acl_entry_short);
125 break;
126
127 default:
128 goto fail;
129 }
130 }
131 return (char *)ext_acl;
132
133fail:
134 kfree(ext_acl);
135 return ERR_PTR(-EINVAL);
136}
137
138
139
140
141
142
143struct posix_acl *
144ext4_get_acl(struct inode *inode, int type)
145{
146 int name_index;
147 char *value = NULL;
148 struct posix_acl *acl;
149 int retval;
150
151 switch (type) {
152 case ACL_TYPE_ACCESS:
153 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
154 break;
155 case ACL_TYPE_DEFAULT:
156 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
157 break;
158 default:
159 BUG();
160 }
161 retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
162 if (retval > 0) {
163 value = kmalloc(retval, GFP_NOFS);
164 if (!value)
165 return ERR_PTR(-ENOMEM);
166 retval = ext4_xattr_get(inode, name_index, "", value, retval);
167 }
168 if (retval > 0)
169 acl = ext4_acl_from_disk(value, retval);
170 else if (retval == -ENODATA || retval == -ENOSYS)
171 acl = NULL;
172 else
173 acl = ERR_PTR(retval);
174 kfree(value);
175
176 return acl;
177}
178
179
180
181
182
183
184static int
185__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
186 struct posix_acl *acl)
187{
188 int name_index;
189 void *value = NULL;
190 size_t size = 0;
191 int error;
192
193 switch (type) {
194 case ACL_TYPE_ACCESS:
195 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
196 if (acl) {
197 error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
198 if (error)
199 return error;
200 inode->i_ctime = current_time(inode);
201 ext4_mark_inode_dirty(handle, inode);
202 }
203 break;
204
205 case ACL_TYPE_DEFAULT:
206 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
207 if (!S_ISDIR(inode->i_mode))
208 return acl ? -EACCES : 0;
209 break;
210
211 default:
212 return -EINVAL;
213 }
214 if (acl) {
215 value = ext4_acl_to_disk(acl, &size);
216 if (IS_ERR(value))
217 return (int)PTR_ERR(value);
218 }
219
220 error = ext4_xattr_set_handle(handle, inode, name_index, "",
221 value, size, 0);
222
223 kfree(value);
224 if (!error)
225 set_cached_acl(inode, type, acl);
226
227 return error;
228}
229
230int
231ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
232{
233 handle_t *handle;
234 int error, retries = 0;
235
236 error = dquot_initialize(inode);
237 if (error)
238 return error;
239retry:
240 handle = ext4_journal_start(inode, EXT4_HT_XATTR,
241 ext4_jbd2_credits_xattr(inode));
242 if (IS_ERR(handle))
243 return PTR_ERR(handle);
244
245 error = __ext4_set_acl(handle, inode, type, acl);
246 ext4_journal_stop(handle);
247 if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
248 goto retry;
249 return error;
250}
251
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255
256
257
258int
259ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
260{
261 struct posix_acl *default_acl, *acl;
262 int error;
263
264 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
265 if (error)
266 return error;
267
268 if (default_acl) {
269 error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
270 default_acl);
271 posix_acl_release(default_acl);
272 }
273 if (acl) {
274 if (!error)
275 error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
276 acl);
277 posix_acl_release(acl);
278 }
279 return error;
280}
281
