Commit | Line | Data |
---|---|---|
ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/acl.c |
ac27a0ec DK |
3 | * |
4 | * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> | |
5 | */ | |
6 | ||
7 | #include <linux/init.h> | |
8 | #include <linux/sched.h> | |
9 | #include <linux/slab.h> | |
10 | #include <linux/capability.h> | |
11 | #include <linux/fs.h> | |
3dcf5451 CH |
12 | #include "ext4_jbd2.h" |
13 | #include "ext4.h" | |
ac27a0ec DK |
14 | #include "xattr.h" |
15 | #include "acl.h" | |
16 | ||
17 | /* | |
18 | * Convert from filesystem to in-memory representation. | |
19 | */ | |
20 | static struct posix_acl * | |
617ba13b | 21 | ext4_acl_from_disk(const void *value, size_t size) |
ac27a0ec DK |
22 | { |
23 | const char *end = (char *)value + size; | |
24 | int n, count; | |
25 | struct posix_acl *acl; | |
26 | ||
27 | if (!value) | |
28 | return NULL; | |
617ba13b | 29 | if (size < sizeof(ext4_acl_header)) |
ac27a0ec | 30 | return ERR_PTR(-EINVAL); |
617ba13b MC |
31 | if (((ext4_acl_header *)value)->a_version != |
32 | cpu_to_le32(EXT4_ACL_VERSION)) | |
ac27a0ec | 33 | return ERR_PTR(-EINVAL); |
617ba13b MC |
34 | value = (char *)value + sizeof(ext4_acl_header); |
35 | count = ext4_acl_count(size); | |
ac27a0ec DK |
36 | if (count < 0) |
37 | return ERR_PTR(-EINVAL); | |
38 | if (count == 0) | |
39 | return NULL; | |
216553c4 | 40 | acl = posix_acl_alloc(count, GFP_NOFS); |
ac27a0ec DK |
41 | if (!acl) |
42 | return ERR_PTR(-ENOMEM); | |
2b2d6d01 | 43 | for (n = 0; n < count; n++) { |
617ba13b MC |
44 | ext4_acl_entry *entry = |
45 | (ext4_acl_entry *)value; | |
46 | if ((char *)value + sizeof(ext4_acl_entry_short) > end) | |
ac27a0ec DK |
47 | goto fail; |
48 | acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); | |
49 | acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); | |
2b2d6d01 TT |
50 | |
51 | switch (acl->a_entries[n].e_tag) { | |
52 | case ACL_USER_OBJ: | |
53 | case ACL_GROUP_OBJ: | |
54 | case ACL_MASK: | |
55 | case ACL_OTHER: | |
56 | value = (char *)value + | |
57 | sizeof(ext4_acl_entry_short); | |
2b2d6d01 TT |
58 | break; |
59 | ||
60 | case ACL_USER: | |
af84df93 EB |
61 | value = (char *)value + sizeof(ext4_acl_entry); |
62 | if ((char *)value > end) | |
63 | goto fail; | |
64 | acl->a_entries[n].e_uid = | |
65 | make_kuid(&init_user_ns, | |
66 | le32_to_cpu(entry->e_id)); | |
67 | break; | |
2b2d6d01 TT |
68 | case ACL_GROUP: |
69 | value = (char *)value + sizeof(ext4_acl_entry); | |
70 | if ((char *)value > end) | |
ac27a0ec | 71 | goto fail; |
af84df93 EB |
72 | acl->a_entries[n].e_gid = |
73 | make_kgid(&init_user_ns, | |
74 | le32_to_cpu(entry->e_id)); | |
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 * | |
617ba13b | 94 | ext4_acl_to_disk(const struct posix_acl *acl, size_t *size) |
ac27a0ec | 95 | { |
617ba13b | 96 | ext4_acl_header *ext_acl; |
ac27a0ec DK |
97 | char *e; |
98 | size_t n; | |
99 | ||
617ba13b MC |
100 | *size = ext4_acl_size(acl->a_count); |
101 | ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count * | |
216553c4 | 102 | sizeof(ext4_acl_entry), GFP_NOFS); |
ac27a0ec DK |
103 | if (!ext_acl) |
104 | return ERR_PTR(-ENOMEM); | |
617ba13b MC |
105 | ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION); |
106 | e = (char *)ext_acl + sizeof(ext4_acl_header); | |
2b2d6d01 | 107 | for (n = 0; n < acl->a_count; n++) { |
af84df93 | 108 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; |
617ba13b | 109 | ext4_acl_entry *entry = (ext4_acl_entry *)e; |
af84df93 EB |
110 | entry->e_tag = cpu_to_le16(acl_e->e_tag); |
111 | entry->e_perm = cpu_to_le16(acl_e->e_perm); | |
112 | switch (acl_e->e_tag) { | |
2b2d6d01 | 113 | case ACL_USER: |
af84df93 EB |
114 | entry->e_id = cpu_to_le32( |
115 | from_kuid(&init_user_ns, acl_e->e_uid)); | |
116 | e += sizeof(ext4_acl_entry); | |
117 | break; | |
2b2d6d01 | 118 | case ACL_GROUP: |
af84df93 EB |
119 | entry->e_id = cpu_to_le32( |
120 | from_kgid(&init_user_ns, acl_e->e_gid)); | |
2b2d6d01 TT |
121 | e += sizeof(ext4_acl_entry); |
122 | break; | |
123 | ||
124 | case ACL_USER_OBJ: | |
125 | case ACL_GROUP_OBJ: | |
126 | case ACL_MASK: | |
127 | case ACL_OTHER: | |
128 | e += sizeof(ext4_acl_entry_short); | |
129 | break; | |
130 | ||
131 | default: | |
132 | goto fail; | |
ac27a0ec DK |
133 | } |
134 | } | |
135 | return (char *)ext_acl; | |
136 | ||
137 | fail: | |
138 | kfree(ext_acl); | |
139 | return ERR_PTR(-EINVAL); | |
140 | } | |
141 | ||
ac27a0ec DK |
142 | /* |
143 | * Inode operation get_posix_acl(). | |
144 | * | |
145 | * inode->i_mutex: don't care | |
146 | */ | |
4e34e719 | 147 | struct posix_acl * |
617ba13b | 148 | ext4_get_acl(struct inode *inode, int type) |
ac27a0ec | 149 | { |
ac27a0ec DK |
150 | int name_index; |
151 | char *value = NULL; | |
152 | struct posix_acl *acl; | |
153 | int retval; | |
154 | ||
2b2d6d01 TT |
155 | switch (type) { |
156 | case ACL_TYPE_ACCESS: | |
2b2d6d01 TT |
157 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; |
158 | break; | |
2b2d6d01 | 159 | case ACL_TYPE_DEFAULT: |
2b2d6d01 TT |
160 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; |
161 | break; | |
2b2d6d01 | 162 | default: |
073aaa1b | 163 | BUG(); |
ac27a0ec | 164 | } |
617ba13b | 165 | retval = ext4_xattr_get(inode, name_index, "", NULL, 0); |
ac27a0ec | 166 | if (retval > 0) { |
216553c4 | 167 | value = kmalloc(retval, GFP_NOFS); |
ac27a0ec DK |
168 | if (!value) |
169 | return ERR_PTR(-ENOMEM); | |
617ba13b | 170 | retval = ext4_xattr_get(inode, name_index, "", value, retval); |
ac27a0ec DK |
171 | } |
172 | if (retval > 0) | |
617ba13b | 173 | acl = ext4_acl_from_disk(value, retval); |
ac27a0ec DK |
174 | else if (retval == -ENODATA || retval == -ENOSYS) |
175 | acl = NULL; | |
176 | else | |
177 | acl = ERR_PTR(retval); | |
178 | kfree(value); | |
179 | ||
073aaa1b AV |
180 | if (!IS_ERR(acl)) |
181 | set_cached_acl(inode, type, acl); | |
2b2d6d01 | 182 | |
ac27a0ec DK |
183 | return acl; |
184 | } | |
185 | ||
186 | /* | |
187 | * Set the access or default ACL of an inode. | |
188 | * | |
617ba13b | 189 | * inode->i_mutex: down unless called from ext4_new_inode |
ac27a0ec DK |
190 | */ |
191 | static int | |
64e178a7 | 192 | __ext4_set_acl(handle_t *handle, struct inode *inode, int type, |
ac27a0ec DK |
193 | struct posix_acl *acl) |
194 | { | |
ac27a0ec DK |
195 | int name_index; |
196 | void *value = NULL; | |
197 | size_t size = 0; | |
198 | int error; | |
199 | ||
2b2d6d01 TT |
200 | switch (type) { |
201 | case ACL_TYPE_ACCESS: | |
202 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; | |
203 | if (acl) { | |
d6952123 | 204 | error = posix_acl_equiv_mode(acl, &inode->i_mode); |
2b2d6d01 TT |
205 | if (error < 0) |
206 | return error; | |
207 | else { | |
c6ac12a6 | 208 | inode->i_ctime = ext4_current_time(inode); |
2b2d6d01 TT |
209 | ext4_mark_inode_dirty(handle, inode); |
210 | if (error == 0) | |
211 | acl = NULL; | |
ac27a0ec | 212 | } |
2b2d6d01 TT |
213 | } |
214 | break; | |
ac27a0ec | 215 | |
2b2d6d01 TT |
216 | case ACL_TYPE_DEFAULT: |
217 | name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
218 | if (!S_ISDIR(inode->i_mode)) | |
219 | return acl ? -EACCES : 0; | |
220 | break; | |
ac27a0ec | 221 | |
2b2d6d01 TT |
222 | default: |
223 | return -EINVAL; | |
ac27a0ec DK |
224 | } |
225 | if (acl) { | |
617ba13b | 226 | value = ext4_acl_to_disk(acl, &size); |
ac27a0ec DK |
227 | if (IS_ERR(value)) |
228 | return (int)PTR_ERR(value); | |
229 | } | |
230 | ||
617ba13b | 231 | error = ext4_xattr_set_handle(handle, inode, name_index, "", |
ac27a0ec DK |
232 | value, size, 0); |
233 | ||
234 | kfree(value); | |
073aaa1b AV |
235 | if (!error) |
236 | set_cached_acl(inode, type, acl); | |
2b2d6d01 | 237 | |
ac27a0ec DK |
238 | return error; |
239 | } | |
240 | ||
ac27a0ec | 241 | int |
64e178a7 | 242 | ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type) |
ac27a0ec | 243 | { |
bc26ab5f | 244 | handle_t *handle; |
64e178a7 | 245 | int error, retries = 0; |
bc26ab5f | 246 | |
bc26ab5f | 247 | retry: |
9924a92a | 248 | handle = ext4_journal_start(inode, EXT4_HT_XATTR, |
95eaefbd | 249 | ext4_jbd2_credits_xattr(inode)); |
64e178a7 CH |
250 | if (IS_ERR(handle)) |
251 | return PTR_ERR(handle); | |
252 | ||
253 | error = __ext4_set_acl(handle, inode, type, acl); | |
bc26ab5f | 254 | ext4_journal_stop(handle); |
64e178a7 | 255 | if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
bc26ab5f | 256 | goto retry; |
ac27a0ec DK |
257 | return error; |
258 | } | |
259 | ||
260 | /* | |
64e178a7 CH |
261 | * Initialize the ACLs of a new inode. Called from ext4_new_inode. |
262 | * | |
263 | * dir->i_mutex: down | |
264 | * inode->i_mutex: up (access to inode is still exclusive) | |
ac27a0ec | 265 | */ |
64e178a7 CH |
266 | int |
267 | ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir) | |
ac27a0ec | 268 | { |
64e178a7 | 269 | struct posix_acl *default_acl, *acl; |
ac27a0ec DK |
270 | int error; |
271 | ||
64e178a7 CH |
272 | error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); |
273 | if (error) | |
274 | return error; | |
ac27a0ec | 275 | |
64e178a7 CH |
276 | if (default_acl) { |
277 | error = __ext4_set_acl(handle, inode, ACL_TYPE_DEFAULT, | |
278 | default_acl); | |
279 | posix_acl_release(default_acl); | |
280 | } | |
281 | if (acl) { | |
282 | if (!error) | |
283 | error = __ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, | |
284 | acl); | |
285 | posix_acl_release(acl); | |
24ec19b0 | 286 | } |
ac27a0ec DK |
287 | return error; |
288 | } |