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1 | #include <linux/capability.h> | |
2 | #include <linux/fs.h> | |
3 | #include <linux/posix_acl.h> | |
4 | #include "reiserfs.h" | |
5 | #include <linux/errno.h> | |
6 | #include <linux/pagemap.h> | |
7 | #include <linux/xattr.h> | |
8 | #include <linux/slab.h> | |
9 | #include <linux/posix_acl_xattr.h> | |
10 | #include "xattr.h" | |
11 | #include "acl.h" | |
12 | #include <asm/uaccess.h> | |
13 | ||
14 | static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th, | |
15 | struct inode *inode, int type, | |
16 | struct posix_acl *acl); | |
17 | ||
18 | ||
19 | int | |
20 | reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) | |
21 | { | |
22 | int error, error2; | |
23 | struct reiserfs_transaction_handle th; | |
24 | size_t jcreate_blocks; | |
25 | int size = acl ? posix_acl_xattr_size(acl->a_count) : 0; | |
26 | ||
27 | ||
28 | /* Pessimism: We can't assume that anything from the xattr root up | |
29 | * has been created. */ | |
30 | ||
31 | jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + | |
32 | reiserfs_xattr_nblocks(inode, size) * 2; | |
33 | ||
34 | reiserfs_write_lock(inode->i_sb); | |
35 | error = journal_begin(&th, inode->i_sb, jcreate_blocks); | |
36 | reiserfs_write_unlock(inode->i_sb); | |
37 | if (error == 0) { | |
38 | error = __reiserfs_set_acl(&th, inode, type, acl); | |
39 | reiserfs_write_lock(inode->i_sb); | |
40 | error2 = journal_end(&th, inode->i_sb, jcreate_blocks); | |
41 | reiserfs_write_unlock(inode->i_sb); | |
42 | if (error2) | |
43 | error = error2; | |
44 | } | |
45 | ||
46 | return error; | |
47 | } | |
48 | ||
49 | /* | |
50 | * Convert from filesystem to in-memory representation. | |
51 | */ | |
52 | static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size) | |
53 | { | |
54 | const char *end = (char *)value + size; | |
55 | int n, count; | |
56 | struct posix_acl *acl; | |
57 | ||
58 | if (!value) | |
59 | return NULL; | |
60 | if (size < sizeof(reiserfs_acl_header)) | |
61 | return ERR_PTR(-EINVAL); | |
62 | if (((reiserfs_acl_header *) value)->a_version != | |
63 | cpu_to_le32(REISERFS_ACL_VERSION)) | |
64 | return ERR_PTR(-EINVAL); | |
65 | value = (char *)value + sizeof(reiserfs_acl_header); | |
66 | count = reiserfs_acl_count(size); | |
67 | if (count < 0) | |
68 | return ERR_PTR(-EINVAL); | |
69 | if (count == 0) | |
70 | return NULL; | |
71 | acl = posix_acl_alloc(count, GFP_NOFS); | |
72 | if (!acl) | |
73 | return ERR_PTR(-ENOMEM); | |
74 | for (n = 0; n < count; n++) { | |
75 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; | |
76 | if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) | |
77 | goto fail; | |
78 | acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); | |
79 | acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); | |
80 | switch (acl->a_entries[n].e_tag) { | |
81 | case ACL_USER_OBJ: | |
82 | case ACL_GROUP_OBJ: | |
83 | case ACL_MASK: | |
84 | case ACL_OTHER: | |
85 | value = (char *)value + | |
86 | sizeof(reiserfs_acl_entry_short); | |
87 | break; | |
88 | ||
89 | case ACL_USER: | |
90 | value = (char *)value + sizeof(reiserfs_acl_entry); | |
91 | if ((char *)value > end) | |
92 | goto fail; | |
93 | acl->a_entries[n].e_uid = | |
94 | make_kuid(&init_user_ns, | |
95 | le32_to_cpu(entry->e_id)); | |
96 | break; | |
97 | case ACL_GROUP: | |
98 | value = (char *)value + sizeof(reiserfs_acl_entry); | |
99 | if ((char *)value > end) | |
100 | goto fail; | |
101 | acl->a_entries[n].e_gid = | |
102 | make_kgid(&init_user_ns, | |
103 | le32_to_cpu(entry->e_id)); | |
104 | break; | |
105 | ||
106 | default: | |
107 | goto fail; | |
108 | } | |
109 | } | |
110 | if (value != end) | |
111 | goto fail; | |
112 | return acl; | |
113 | ||
114 | fail: | |
115 | posix_acl_release(acl); | |
116 | return ERR_PTR(-EINVAL); | |
117 | } | |
118 | ||
119 | /* | |
120 | * Convert from in-memory to filesystem representation. | |
121 | */ | |
122 | static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size) | |
123 | { | |
124 | reiserfs_acl_header *ext_acl; | |
125 | char *e; | |
126 | int n; | |
127 | ||
128 | *size = reiserfs_acl_size(acl->a_count); | |
129 | ext_acl = kmalloc(sizeof(reiserfs_acl_header) + | |
130 | acl->a_count * | |
131 | sizeof(reiserfs_acl_entry), | |
132 | GFP_NOFS); | |
133 | if (!ext_acl) | |
134 | return ERR_PTR(-ENOMEM); | |
135 | ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); | |
136 | e = (char *)ext_acl + sizeof(reiserfs_acl_header); | |
137 | for (n = 0; n < acl->a_count; n++) { | |
138 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
139 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; | |
140 | entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); | |
141 | entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); | |
142 | switch (acl->a_entries[n].e_tag) { | |
143 | case ACL_USER: | |
144 | entry->e_id = cpu_to_le32( | |
145 | from_kuid(&init_user_ns, acl_e->e_uid)); | |
146 | e += sizeof(reiserfs_acl_entry); | |
147 | break; | |
148 | case ACL_GROUP: | |
149 | entry->e_id = cpu_to_le32( | |
150 | from_kgid(&init_user_ns, acl_e->e_gid)); | |
151 | e += sizeof(reiserfs_acl_entry); | |
152 | break; | |
153 | ||
154 | case ACL_USER_OBJ: | |
155 | case ACL_GROUP_OBJ: | |
156 | case ACL_MASK: | |
157 | case ACL_OTHER: | |
158 | e += sizeof(reiserfs_acl_entry_short); | |
159 | break; | |
160 | ||
161 | default: | |
162 | goto fail; | |
163 | } | |
164 | } | |
165 | return (char *)ext_acl; | |
166 | ||
167 | fail: | |
168 | kfree(ext_acl); | |
169 | return ERR_PTR(-EINVAL); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Inode operation get_posix_acl(). | |
174 | * | |
175 | * inode->i_mutex: down | |
176 | * BKL held [before 2.5.x] | |
177 | */ | |
178 | struct posix_acl *reiserfs_get_acl(struct inode *inode, int type) | |
179 | { | |
180 | char *name, *value; | |
181 | struct posix_acl *acl; | |
182 | int size; | |
183 | int retval; | |
184 | ||
185 | switch (type) { | |
186 | case ACL_TYPE_ACCESS: | |
187 | name = POSIX_ACL_XATTR_ACCESS; | |
188 | break; | |
189 | case ACL_TYPE_DEFAULT: | |
190 | name = POSIX_ACL_XATTR_DEFAULT; | |
191 | break; | |
192 | default: | |
193 | BUG(); | |
194 | } | |
195 | ||
196 | size = reiserfs_xattr_get(inode, name, NULL, 0); | |
197 | if (size < 0) { | |
198 | if (size == -ENODATA || size == -ENOSYS) { | |
199 | set_cached_acl(inode, type, NULL); | |
200 | return NULL; | |
201 | } | |
202 | return ERR_PTR(size); | |
203 | } | |
204 | ||
205 | value = kmalloc(size, GFP_NOFS); | |
206 | if (!value) | |
207 | return ERR_PTR(-ENOMEM); | |
208 | ||
209 | retval = reiserfs_xattr_get(inode, name, value, size); | |
210 | if (retval == -ENODATA || retval == -ENOSYS) { | |
211 | /* This shouldn't actually happen as it should have | |
212 | been caught above.. but just in case */ | |
213 | acl = NULL; | |
214 | } else if (retval < 0) { | |
215 | acl = ERR_PTR(retval); | |
216 | } else { | |
217 | acl = reiserfs_posix_acl_from_disk(value, retval); | |
218 | } | |
219 | if (!IS_ERR(acl)) | |
220 | set_cached_acl(inode, type, acl); | |
221 | ||
222 | kfree(value); | |
223 | return acl; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Inode operation set_posix_acl(). | |
228 | * | |
229 | * inode->i_mutex: down | |
230 | * BKL held [before 2.5.x] | |
231 | */ | |
232 | static int | |
233 | __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, | |
234 | int type, struct posix_acl *acl) | |
235 | { | |
236 | char *name; | |
237 | void *value = NULL; | |
238 | size_t size = 0; | |
239 | int error; | |
240 | ||
241 | switch (type) { | |
242 | case ACL_TYPE_ACCESS: | |
243 | name = POSIX_ACL_XATTR_ACCESS; | |
244 | if (acl) { | |
245 | error = posix_acl_equiv_mode(acl, &inode->i_mode); | |
246 | if (error < 0) | |
247 | return error; | |
248 | else { | |
249 | if (error == 0) | |
250 | acl = NULL; | |
251 | } | |
252 | } | |
253 | break; | |
254 | case ACL_TYPE_DEFAULT: | |
255 | name = POSIX_ACL_XATTR_DEFAULT; | |
256 | if (!S_ISDIR(inode->i_mode)) | |
257 | return acl ? -EACCES : 0; | |
258 | break; | |
259 | default: | |
260 | return -EINVAL; | |
261 | } | |
262 | ||
263 | if (acl) { | |
264 | value = reiserfs_posix_acl_to_disk(acl, &size); | |
265 | if (IS_ERR(value)) | |
266 | return (int)PTR_ERR(value); | |
267 | } | |
268 | ||
269 | error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); | |
270 | ||
271 | /* | |
272 | * Ensure that the inode gets dirtied if we're only using | |
273 | * the mode bits and an old ACL didn't exist. We don't need | |
274 | * to check if the inode is hashed here since we won't get | |
275 | * called by reiserfs_inherit_default_acl(). | |
276 | */ | |
277 | if (error == -ENODATA) { | |
278 | error = 0; | |
279 | if (type == ACL_TYPE_ACCESS) { | |
280 | inode->i_ctime = CURRENT_TIME_SEC; | |
281 | mark_inode_dirty(inode); | |
282 | } | |
283 | } | |
284 | ||
285 | kfree(value); | |
286 | ||
287 | if (!error) | |
288 | set_cached_acl(inode, type, acl); | |
289 | ||
290 | return error; | |
291 | } | |
292 | ||
293 | /* dir->i_mutex: locked, | |
294 | * inode is new and not released into the wild yet */ | |
295 | int | |
296 | reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, | |
297 | struct inode *dir, struct dentry *dentry, | |
298 | struct inode *inode) | |
299 | { | |
300 | struct posix_acl *default_acl, *acl; | |
301 | int err = 0; | |
302 | ||
303 | /* ACLs only get applied to files and directories */ | |
304 | if (S_ISLNK(inode->i_mode)) | |
305 | return 0; | |
306 | ||
307 | /* ACLs can only be used on "new" objects, so if it's an old object | |
308 | * there is nothing to inherit from */ | |
309 | if (get_inode_sd_version(dir) == STAT_DATA_V1) | |
310 | goto apply_umask; | |
311 | ||
312 | /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This | |
313 | * would be useless since permissions are ignored, and a pain because | |
314 | * it introduces locking cycles */ | |
315 | if (IS_PRIVATE(dir)) { | |
316 | inode->i_flags |= S_PRIVATE; | |
317 | goto apply_umask; | |
318 | } | |
319 | ||
320 | err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); | |
321 | if (err) | |
322 | return err; | |
323 | ||
324 | if (default_acl) { | |
325 | err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, | |
326 | default_acl); | |
327 | posix_acl_release(default_acl); | |
328 | } | |
329 | if (acl) { | |
330 | if (!err) | |
331 | err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, | |
332 | acl); | |
333 | posix_acl_release(acl); | |
334 | } | |
335 | ||
336 | return err; | |
337 | ||
338 | apply_umask: | |
339 | /* no ACL, apply umask */ | |
340 | inode->i_mode &= ~current_umask(); | |
341 | return err; | |
342 | } | |
343 | ||
344 | /* This is used to cache the default acl before a new object is created. | |
345 | * The biggest reason for this is to get an idea of how many blocks will | |
346 | * actually be required for the create operation if we must inherit an ACL. | |
347 | * An ACL write can add up to 3 object creations and an additional file write | |
348 | * so we'd prefer not to reserve that many blocks in the journal if we can. | |
349 | * It also has the advantage of not loading the ACL with a transaction open, | |
350 | * this may seem silly, but if the owner of the directory is doing the | |
351 | * creation, the ACL may not be loaded since the permissions wouldn't require | |
352 | * it. | |
353 | * We return the number of blocks required for the transaction. | |
354 | */ | |
355 | int reiserfs_cache_default_acl(struct inode *inode) | |
356 | { | |
357 | struct posix_acl *acl; | |
358 | int nblocks = 0; | |
359 | ||
360 | if (IS_PRIVATE(inode)) | |
361 | return 0; | |
362 | ||
363 | acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT); | |
364 | ||
365 | if (acl && !IS_ERR(acl)) { | |
366 | int size = reiserfs_acl_size(acl->a_count); | |
367 | ||
368 | /* Other xattrs can be created during inode creation. We don't | |
369 | * want to claim too many blocks, so we check to see if we | |
370 | * we need to create the tree to the xattrs, and then we | |
371 | * just want two files. */ | |
372 | nblocks = reiserfs_xattr_jcreate_nblocks(inode); | |
373 | nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); | |
374 | ||
375 | REISERFS_I(inode)->i_flags |= i_has_xattr_dir; | |
376 | ||
377 | /* We need to account for writes + bitmaps for two files */ | |
378 | nblocks += reiserfs_xattr_nblocks(inode, size) * 4; | |
379 | posix_acl_release(acl); | |
380 | } | |
381 | ||
382 | return nblocks; | |
383 | } | |
384 | ||
385 | /* | |
386 | * Called under i_mutex | |
387 | */ | |
388 | int reiserfs_acl_chmod(struct inode *inode) | |
389 | { | |
390 | if (IS_PRIVATE(inode)) | |
391 | return 0; | |
392 | if (get_inode_sd_version(inode) == STAT_DATA_V1 || | |
393 | !reiserfs_posixacl(inode->i_sb)) | |
394 | return 0; | |
395 | ||
396 | return posix_acl_chmod(inode, inode->i_mode); | |
397 | } |