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Merge tag 'mmc-4.1-rc1' of git://git.linaro.org/people/ulf.hansson/mmc
[mirror_ubuntu-zesty-kernel.git] / fs / ext4 / acl.c
CommitLineData
ac27a0ec 1/*
617ba13b 2 * linux/fs/ext4/acl.c
ac27a0ec
DK
3 *
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
5 */
6
3dcf5451
CH
7#include "ext4_jbd2.h"
8#include "ext4.h"
ac27a0ec
DK
9#include "xattr.h"
10#include "acl.h"
11
12/*
13 * Convert from filesystem to in-memory representation.
14 */
15static struct posix_acl *
617ba13b 16ext4_acl_from_disk(const void *value, size_t size)
ac27a0ec
DK
17{
18 const char *end = (char *)value + size;
19 int n, count;
20 struct posix_acl *acl;
21
22 if (!value)
23 return NULL;
617ba13b 24 if (size < sizeof(ext4_acl_header))
ac27a0ec 25 return ERR_PTR(-EINVAL);
617ba13b
MC
26 if (((ext4_acl_header *)value)->a_version !=
27 cpu_to_le32(EXT4_ACL_VERSION))
ac27a0ec 28 return ERR_PTR(-EINVAL);
617ba13b
MC
29 value = (char *)value + sizeof(ext4_acl_header);
30 count = ext4_acl_count(size);
ac27a0ec
DK
31 if (count < 0)
32 return ERR_PTR(-EINVAL);
33 if (count == 0)
34 return NULL;
216553c4 35 acl = posix_acl_alloc(count, GFP_NOFS);
ac27a0ec
DK
36 if (!acl)
37 return ERR_PTR(-ENOMEM);
2b2d6d01 38 for (n = 0; n < count; n++) {
617ba13b
MC
39 ext4_acl_entry *entry =
40 (ext4_acl_entry *)value;
41 if ((char *)value + sizeof(ext4_acl_entry_short) > end)
ac27a0ec
DK
42 goto fail;
43 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
44 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
2b2d6d01
TT
45
46 switch (acl->a_entries[n].e_tag) {
47 case ACL_USER_OBJ:
48 case ACL_GROUP_OBJ:
49 case ACL_MASK:
50 case ACL_OTHER:
51 value = (char *)value +
52 sizeof(ext4_acl_entry_short);
2b2d6d01
TT
53 break;
54
55 case ACL_USER:
af84df93
EB
56 value = (char *)value + sizeof(ext4_acl_entry);
57 if ((char *)value > end)
58 goto fail;
59 acl->a_entries[n].e_uid =
60 make_kuid(&init_user_ns,
61 le32_to_cpu(entry->e_id));
62 break;
2b2d6d01
TT
63 case ACL_GROUP:
64 value = (char *)value + sizeof(ext4_acl_entry);
65 if ((char *)value > end)
ac27a0ec 66 goto fail;
af84df93
EB
67 acl->a_entries[n].e_gid =
68 make_kgid(&init_user_ns,
69 le32_to_cpu(entry->e_id));
2b2d6d01
TT
70 break;
71
72 default:
73 goto fail;
ac27a0ec
DK
74 }
75 }
76 if (value != end)
77 goto fail;
78 return acl;
79
80fail:
81 posix_acl_release(acl);
82 return ERR_PTR(-EINVAL);
83}
84
85/*
86 * Convert from in-memory to filesystem representation.
87 */
88static void *
617ba13b 89ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
ac27a0ec 90{
617ba13b 91 ext4_acl_header *ext_acl;
ac27a0ec
DK
92 char *e;
93 size_t n;
94
617ba13b
MC
95 *size = ext4_acl_size(acl->a_count);
96 ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
216553c4 97 sizeof(ext4_acl_entry), GFP_NOFS);
ac27a0ec
DK
98 if (!ext_acl)
99 return ERR_PTR(-ENOMEM);
617ba13b
MC
100 ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
101 e = (char *)ext_acl + sizeof(ext4_acl_header);
2b2d6d01 102 for (n = 0; n < acl->a_count; n++) {
af84df93 103 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
617ba13b 104 ext4_acl_entry *entry = (ext4_acl_entry *)e;
af84df93
EB
105 entry->e_tag = cpu_to_le16(acl_e->e_tag);
106 entry->e_perm = cpu_to_le16(acl_e->e_perm);
107 switch (acl_e->e_tag) {
2b2d6d01 108 case ACL_USER:
af84df93
EB
109 entry->e_id = cpu_to_le32(
110 from_kuid(&init_user_ns, acl_e->e_uid));
111 e += sizeof(ext4_acl_entry);
112 break;
2b2d6d01 113 case ACL_GROUP:
af84df93
EB
114 entry->e_id = cpu_to_le32(
115 from_kgid(&init_user_ns, acl_e->e_gid));
2b2d6d01
TT
116 e += sizeof(ext4_acl_entry);
117 break;
118
119 case ACL_USER_OBJ:
120 case ACL_GROUP_OBJ:
121 case ACL_MASK:
122 case ACL_OTHER:
123 e += sizeof(ext4_acl_entry_short);
124 break;
125
126 default:
127 goto fail;
ac27a0ec
DK
128 }
129 }
130 return (char *)ext_acl;
131
132fail:
133 kfree(ext_acl);
134 return ERR_PTR(-EINVAL);
135}
136
ac27a0ec
DK
137/*
138 * Inode operation get_posix_acl().
139 *
140 * inode->i_mutex: don't care
141 */
4e34e719 142struct posix_acl *
617ba13b 143ext4_get_acl(struct inode *inode, int type)
ac27a0ec 144{
ac27a0ec
DK
145 int name_index;
146 char *value = NULL;
147 struct posix_acl *acl;
148 int retval;
149
2b2d6d01
TT
150 switch (type) {
151 case ACL_TYPE_ACCESS:
2b2d6d01
TT
152 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
153 break;
2b2d6d01 154 case ACL_TYPE_DEFAULT:
2b2d6d01
TT
155 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
156 break;
2b2d6d01 157 default:
073aaa1b 158 BUG();
ac27a0ec 159 }
617ba13b 160 retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
ac27a0ec 161 if (retval > 0) {
216553c4 162 value = kmalloc(retval, GFP_NOFS);
ac27a0ec
DK
163 if (!value)
164 return ERR_PTR(-ENOMEM);
617ba13b 165 retval = ext4_xattr_get(inode, name_index, "", value, retval);
ac27a0ec
DK
166 }
167 if (retval > 0)
617ba13b 168 acl = ext4_acl_from_disk(value, retval);
ac27a0ec
DK
169 else if (retval == -ENODATA || retval == -ENOSYS)
170 acl = NULL;
171 else
172 acl = ERR_PTR(retval);
173 kfree(value);
174
073aaa1b
AV
175 if (!IS_ERR(acl))
176 set_cached_acl(inode, type, acl);
2b2d6d01 177
ac27a0ec
DK
178 return acl;
179}
180
181/*
182 * Set the access or default ACL of an inode.
183 *
617ba13b 184 * inode->i_mutex: down unless called from ext4_new_inode
ac27a0ec
DK
185 */
186static int
64e178a7 187__ext4_set_acl(handle_t *handle, struct inode *inode, int type,
ac27a0ec
DK
188 struct posix_acl *acl)
189{
ac27a0ec
DK
190 int name_index;
191 void *value = NULL;
192 size_t size = 0;
193 int error;
194
2b2d6d01
TT
195 switch (type) {
196 case ACL_TYPE_ACCESS:
197 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
198 if (acl) {
d6952123 199 error = posix_acl_equiv_mode(acl, &inode->i_mode);
2b2d6d01
TT
200 if (error < 0)
201 return error;
202 else {
c6ac12a6 203 inode->i_ctime = ext4_current_time(inode);
2b2d6d01
TT
204 ext4_mark_inode_dirty(handle, inode);
205 if (error == 0)
206 acl = NULL;
ac27a0ec 207 }
2b2d6d01
TT
208 }
209 break;
ac27a0ec 210
2b2d6d01
TT
211 case ACL_TYPE_DEFAULT:
212 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
213 if (!S_ISDIR(inode->i_mode))
214 return acl ? -EACCES : 0;
215 break;
ac27a0ec 216
2b2d6d01
TT
217 default:
218 return -EINVAL;
ac27a0ec
DK
219 }
220 if (acl) {
617ba13b 221 value = ext4_acl_to_disk(acl, &size);
ac27a0ec
DK
222 if (IS_ERR(value))
223 return (int)PTR_ERR(value);
224 }
225
617ba13b 226 error = ext4_xattr_set_handle(handle, inode, name_index, "",
ac27a0ec
DK
227 value, size, 0);
228
229 kfree(value);
073aaa1b
AV
230 if (!error)
231 set_cached_acl(inode, type, acl);
2b2d6d01 232
ac27a0ec
DK
233 return error;
234}
235
ac27a0ec 236int
64e178a7 237ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type)
ac27a0ec 238{
bc26ab5f 239 handle_t *handle;
64e178a7 240 int error, retries = 0;
bc26ab5f 241
bc26ab5f 242retry:
9924a92a 243 handle = ext4_journal_start(inode, EXT4_HT_XATTR,
95eaefbd 244 ext4_jbd2_credits_xattr(inode));
64e178a7
CH
245 if (IS_ERR(handle))
246 return PTR_ERR(handle);
247
248 error = __ext4_set_acl(handle, inode, type, acl);
bc26ab5f 249 ext4_journal_stop(handle);
64e178a7 250 if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
bc26ab5f 251 goto retry;
ac27a0ec
DK
252 return error;
253}
254
255/*
64e178a7
CH
256 * Initialize the ACLs of a new inode. Called from ext4_new_inode.
257 *
258 * dir->i_mutex: down
259 * inode->i_mutex: up (access to inode is still exclusive)
ac27a0ec 260 */
64e178a7
CH
261int
262ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
ac27a0ec 263{
64e178a7 264 struct posix_acl *default_acl, *acl;
ac27a0ec
DK
265 int error;
266
64e178a7
CH
267 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
268 if (error)
269 return error;
ac27a0ec 270
64e178a7
CH
271 if (default_acl) {
272 error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT,
273 default_acl);
274 posix_acl_release(default_acl);
275 }
276 if (acl) {
277 if (!error)
278 error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS,
279 acl);
280 posix_acl_release(acl);
24ec19b0 281 }
ac27a0ec
DK
282 return error;
283}