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Commit | Line | Data |
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ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/acl.c |
ac27a0ec DK |
3 | * |
4 | * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> | |
5 | */ | |
6 | ||
b8cb5a54 | 7 | #include <linux/quotaops.h> |
3dcf5451 CH |
8 | #include "ext4_jbd2.h" |
9 | #include "ext4.h" | |
ac27a0ec DK |
10 | #include "xattr.h" |
11 | #include "acl.h" | |
12 | ||
13 | /* | |
14 | * Convert from filesystem to in-memory representation. | |
15 | */ | |
16 | static struct posix_acl * | |
afdbd4a6 | 17 | ext4_acl_from_disk(struct super_block *sb, const void *value, size_t size) |
ac27a0ec DK |
18 | { |
19 | const char *end = (char *)value + size; | |
20 | int n, count; | |
21 | struct posix_acl *acl; | |
22 | ||
23 | if (!value) | |
24 | return NULL; | |
617ba13b | 25 | if (size < sizeof(ext4_acl_header)) |
ac27a0ec | 26 | return ERR_PTR(-EINVAL); |
617ba13b MC |
27 | if (((ext4_acl_header *)value)->a_version != |
28 | cpu_to_le32(EXT4_ACL_VERSION)) | |
ac27a0ec | 29 | return ERR_PTR(-EINVAL); |
617ba13b MC |
30 | value = (char *)value + sizeof(ext4_acl_header); |
31 | count = ext4_acl_count(size); | |
ac27a0ec DK |
32 | if (count < 0) |
33 | return ERR_PTR(-EINVAL); | |
34 | if (count == 0) | |
35 | return NULL; | |
216553c4 | 36 | acl = posix_acl_alloc(count, GFP_NOFS); |
ac27a0ec DK |
37 | if (!acl) |
38 | return ERR_PTR(-ENOMEM); | |
2b2d6d01 | 39 | for (n = 0; n < count; n++) { |
617ba13b MC |
40 | ext4_acl_entry *entry = |
41 | (ext4_acl_entry *)value; | |
42 | if ((char *)value + sizeof(ext4_acl_entry_short) > end) | |
ac27a0ec DK |
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); | |
2b2d6d01 TT |
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); | |
2b2d6d01 TT |
54 | break; |
55 | ||
56 | case ACL_USER: | |
af84df93 EB |
57 | value = (char *)value + sizeof(ext4_acl_entry); |
58 | if ((char *)value > end) | |
59 | goto fail; | |
60 | acl->a_entries[n].e_uid = | |
afdbd4a6 | 61 | make_kuid(sb->s_user_ns, |
af84df93 | 62 | le32_to_cpu(entry->e_id)); |
afdbd4a6 SF |
63 | if (!uid_valid(acl->a_entries[n].e_uid)) |
64 | goto fail; | |
af84df93 | 65 | break; |
2b2d6d01 TT |
66 | case ACL_GROUP: |
67 | value = (char *)value + sizeof(ext4_acl_entry); | |
68 | if ((char *)value > end) | |
ac27a0ec | 69 | goto fail; |
af84df93 | 70 | acl->a_entries[n].e_gid = |
afdbd4a6 | 71 | make_kgid(sb->s_user_ns, |
af84df93 | 72 | le32_to_cpu(entry->e_id)); |
afdbd4a6 SF |
73 | if (!gid_valid(acl->a_entries[n].e_gid)) |
74 | goto fail; | |
2b2d6d01 TT |
75 | break; |
76 | ||
77 | default: | |
78 | goto fail; | |
ac27a0ec DK |
79 | } |
80 | } | |
81 | if (value != end) | |
82 | goto fail; | |
83 | return acl; | |
84 | ||
85 | fail: | |
86 | posix_acl_release(acl); | |
87 | return ERR_PTR(-EINVAL); | |
88 | } | |
89 | ||
90 | /* | |
91 | * Convert from in-memory to filesystem representation. | |
92 | */ | |
93 | static void * | |
afdbd4a6 SF |
94 | ext4_acl_to_disk(struct super_block *sb, const struct posix_acl *acl, |
95 | size_t *size) | |
ac27a0ec | 96 | { |
617ba13b | 97 | ext4_acl_header *ext_acl; |
ac27a0ec DK |
98 | char *e; |
99 | size_t n; | |
afdbd4a6 SF |
100 | uid_t uid; |
101 | gid_t gid; | |
ac27a0ec | 102 | |
617ba13b MC |
103 | *size = ext4_acl_size(acl->a_count); |
104 | ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count * | |
216553c4 | 105 | sizeof(ext4_acl_entry), GFP_NOFS); |
ac27a0ec DK |
106 | if (!ext_acl) |
107 | return ERR_PTR(-ENOMEM); | |
617ba13b MC |
108 | ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION); |
109 | e = (char *)ext_acl + sizeof(ext4_acl_header); | |
2b2d6d01 | 110 | for (n = 0; n < acl->a_count; n++) { |
af84df93 | 111 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; |
617ba13b | 112 | ext4_acl_entry *entry = (ext4_acl_entry *)e; |
af84df93 EB |
113 | entry->e_tag = cpu_to_le16(acl_e->e_tag); |
114 | entry->e_perm = cpu_to_le16(acl_e->e_perm); | |
115 | switch (acl_e->e_tag) { | |
2b2d6d01 | 116 | case ACL_USER: |
afdbd4a6 SF |
117 | uid = from_kuid(sb->s_user_ns, acl_e->e_uid); |
118 | if (uid == (uid_t)-1) | |
119 | goto fail; | |
120 | entry->e_id = cpu_to_le32(uid); | |
af84df93 EB |
121 | e += sizeof(ext4_acl_entry); |
122 | break; | |
2b2d6d01 | 123 | case ACL_GROUP: |
afdbd4a6 SF |
124 | gid = from_kgid(sb->s_user_ns, acl_e->e_gid); |
125 | if (gid == (gid_t)-1) | |
126 | goto fail; | |
127 | entry->e_id = cpu_to_le32(gid); | |
2b2d6d01 TT |
128 | e += sizeof(ext4_acl_entry); |
129 | break; | |
130 | ||
131 | case ACL_USER_OBJ: | |
132 | case ACL_GROUP_OBJ: | |
133 | case ACL_MASK: | |
134 | case ACL_OTHER: | |
135 | e += sizeof(ext4_acl_entry_short); | |
136 | break; | |
137 | ||
138 | default: | |
139 | goto fail; | |
ac27a0ec DK |
140 | } |
141 | } | |
142 | return (char *)ext_acl; | |
143 | ||
144 | fail: | |
145 | kfree(ext_acl); | |
146 | return ERR_PTR(-EINVAL); | |
147 | } | |
148 | ||
ac27a0ec DK |
149 | /* |
150 | * Inode operation get_posix_acl(). | |
151 | * | |
152 | * inode->i_mutex: don't care | |
153 | */ | |
4e34e719 | 154 | struct posix_acl * |
617ba13b | 155 | ext4_get_acl(struct inode *inode, int type) |
ac27a0ec | 156 | { |
ac27a0ec DK |
157 | int name_index; |
158 | char *value = NULL; | |
159 | struct posix_acl *acl; | |
160 | int retval; | |
161 | ||
2b2d6d01 TT |
162 | switch (type) { |
163 | case ACL_TYPE_ACCESS: | |
2b2d6d01 TT |
164 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; |
165 | break; | |
2b2d6d01 | 166 | case ACL_TYPE_DEFAULT: |
2b2d6d01 TT |
167 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; |
168 | break; | |
2b2d6d01 | 169 | default: |
073aaa1b | 170 | BUG(); |
ac27a0ec | 171 | } |
617ba13b | 172 | retval = ext4_xattr_get(inode, name_index, "", NULL, 0); |
ac27a0ec | 173 | if (retval > 0) { |
216553c4 | 174 | value = kmalloc(retval, GFP_NOFS); |
ac27a0ec DK |
175 | if (!value) |
176 | return ERR_PTR(-ENOMEM); | |
617ba13b | 177 | retval = ext4_xattr_get(inode, name_index, "", value, retval); |
ac27a0ec DK |
178 | } |
179 | if (retval > 0) | |
afdbd4a6 | 180 | acl = ext4_acl_from_disk(inode->i_sb, value, retval); |
ac27a0ec DK |
181 | else if (retval == -ENODATA || retval == -ENOSYS) |
182 | acl = NULL; | |
183 | else | |
184 | acl = ERR_PTR(retval); | |
185 | kfree(value); | |
186 | ||
ac27a0ec DK |
187 | return acl; |
188 | } | |
189 | ||
190 | /* | |
191 | * Set the access or default ACL of an inode. | |
192 | * | |
617ba13b | 193 | * inode->i_mutex: down unless called from ext4_new_inode |
ac27a0ec DK |
194 | */ |
195 | static int | |
64e178a7 | 196 | __ext4_set_acl(handle_t *handle, struct inode *inode, int type, |
af65207c | 197 | struct posix_acl *acl, int xattr_flags) |
ac27a0ec | 198 | { |
ac27a0ec DK |
199 | int name_index; |
200 | void *value = NULL; | |
201 | size_t size = 0; | |
202 | int error; | |
203 | ||
2b2d6d01 TT |
204 | switch (type) { |
205 | case ACL_TYPE_ACCESS: | |
206 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; | |
2b2d6d01 | 207 | break; |
ac27a0ec | 208 | |
2b2d6d01 TT |
209 | case ACL_TYPE_DEFAULT: |
210 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
211 | if (!S_ISDIR(inode->i_mode)) | |
212 | return acl ? -EACCES : 0; | |
213 | break; | |
ac27a0ec | 214 | |
2b2d6d01 TT |
215 | default: |
216 | return -EINVAL; | |
ac27a0ec DK |
217 | } |
218 | if (acl) { | |
afdbd4a6 | 219 | value = ext4_acl_to_disk(inode->i_sb, acl, &size); |
ac27a0ec DK |
220 | if (IS_ERR(value)) |
221 | return (int)PTR_ERR(value); | |
222 | } | |
223 | ||
617ba13b | 224 | error = ext4_xattr_set_handle(handle, inode, name_index, "", |
af65207c | 225 | value, size, xattr_flags); |
ac27a0ec DK |
226 | |
227 | kfree(value); | |
397e4341 | 228 | if (!error) { |
073aaa1b | 229 | set_cached_acl(inode, type, acl); |
397e4341 | 230 | } |
2b2d6d01 | 231 | |
ac27a0ec DK |
232 | return error; |
233 | } | |
234 | ||
ac27a0ec | 235 | int |
64e178a7 | 236 | ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type) |
ac27a0ec | 237 | { |
bc26ab5f | 238 | handle_t *handle; |
c1a5d5f6 TE |
239 | int error, credits, retries = 0; |
240 | size_t acl_size = acl ? ext4_acl_size(acl->a_count) : 0; | |
a3bb2d55 JK |
241 | umode_t mode = inode->i_mode; |
242 | int update_mode = 0; | |
bc26ab5f | 243 | |
b8cb5a54 TE |
244 | error = dquot_initialize(inode); |
245 | if (error) | |
246 | return error; | |
bc26ab5f | 247 | retry: |
af65207c TE |
248 | error = ext4_xattr_set_credits(inode, acl_size, false /* is_create */, |
249 | &credits); | |
dec214d0 TE |
250 | if (error) |
251 | return error; | |
252 | ||
c1a5d5f6 | 253 | handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits); |
64e178a7 CH |
254 | if (IS_ERR(handle)) |
255 | return PTR_ERR(handle); | |
256 | ||
a3bb2d55 JK |
257 | if ((type == ACL_TYPE_ACCESS) && acl) { |
258 | error = posix_acl_update_mode(inode, &mode, &acl); | |
259 | if (error) | |
260 | goto out_stop; | |
261 | update_mode = 1; | |
262 | } | |
263 | ||
af65207c | 264 | error = __ext4_set_acl(handle, inode, type, acl, 0 /* xattr_flags */); |
a3bb2d55 JK |
265 | if (!error && update_mode) { |
266 | inode->i_mode = mode; | |
267 | inode->i_ctime = current_time(inode); | |
268 | ext4_mark_inode_dirty(handle, inode); | |
269 | } | |
270 | out_stop: | |
bc26ab5f | 271 | ext4_journal_stop(handle); |
64e178a7 | 272 | if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
bc26ab5f | 273 | goto retry; |
ac27a0ec DK |
274 | return error; |
275 | } | |
276 | ||
277 | /* | |
64e178a7 CH |
278 | * Initialize the ACLs of a new inode. Called from ext4_new_inode. |
279 | * | |
280 | * dir->i_mutex: down | |
281 | * inode->i_mutex: up (access to inode is still exclusive) | |
ac27a0ec | 282 | */ |
64e178a7 CH |
283 | int |
284 | ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir) | |
ac27a0ec | 285 | { |
64e178a7 | 286 | struct posix_acl *default_acl, *acl; |
ac27a0ec DK |
287 | int error; |
288 | ||
64e178a7 CH |
289 | error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); |
290 | if (error) | |
291 | return error; | |
ac27a0ec | 292 | |
64e178a7 CH |
293 | if (default_acl) { |
294 | error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT, | |
af65207c | 295 | default_acl, XATTR_CREATE); |
64e178a7 CH |
296 | posix_acl_release(default_acl); |
297 | } | |
298 | if (acl) { | |
299 | if (!error) | |
300 | error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, | |
af65207c | 301 | acl, XATTR_CREATE); |
64e178a7 | 302 | posix_acl_release(acl); |
24ec19b0 | 303 | } |
ac27a0ec DK |
304 | return error; |
305 | } |