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 <linux/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
reiserfs_set_acl(struct inode * inode,struct posix_acl * acl,int type)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 /*
29 * Pessimism: We can't assume that anything from the xattr root up
30 * has been created.
31 */
32
33 jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
34 reiserfs_xattr_nblocks(inode, size) * 2;
35
36 reiserfs_write_lock(inode->i_sb);
37 error = journal_begin(&th, inode->i_sb, jcreate_blocks);
38 reiserfs_write_unlock(inode->i_sb);
39 if (error == 0) {
40 if (type == ACL_TYPE_ACCESS && acl) {
41 error = posix_acl_update_mode(inode, &inode->i_mode,
42 &acl);
43 if (error)
44 goto unlock;
45 }
46 error = __reiserfs_set_acl(&th, inode, type, acl);
47 unlock:
48 reiserfs_write_lock(inode->i_sb);
49 error2 = journal_end(&th);
50 reiserfs_write_unlock(inode->i_sb);
51 if (error2)
52 error = error2;
53 }
54
55 return error;
56 }
57
58 /*
59 * Convert from filesystem to in-memory representation.
60 */
reiserfs_posix_acl_from_disk(const void * value,size_t size)61 static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size)
62 {
63 const char *end = (char *)value + size;
64 int n, count;
65 struct posix_acl *acl;
66
67 if (!value)
68 return NULL;
69 if (size < sizeof(reiserfs_acl_header))
70 return ERR_PTR(-EINVAL);
71 if (((reiserfs_acl_header *) value)->a_version !=
72 cpu_to_le32(REISERFS_ACL_VERSION))
73 return ERR_PTR(-EINVAL);
74 value = (char *)value + sizeof(reiserfs_acl_header);
75 count = reiserfs_acl_count(size);
76 if (count < 0)
77 return ERR_PTR(-EINVAL);
78 if (count == 0)
79 return NULL;
80 acl = posix_acl_alloc(count, GFP_NOFS);
81 if (!acl)
82 return ERR_PTR(-ENOMEM);
83 for (n = 0; n < count; n++) {
84 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;
85 if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
86 goto fail;
87 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
88 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
89 switch (acl->a_entries[n].e_tag) {
90 case ACL_USER_OBJ:
91 case ACL_GROUP_OBJ:
92 case ACL_MASK:
93 case ACL_OTHER:
94 value = (char *)value +
95 sizeof(reiserfs_acl_entry_short);
96 break;
97
98 case ACL_USER:
99 value = (char *)value + sizeof(reiserfs_acl_entry);
100 if ((char *)value > end)
101 goto fail;
102 acl->a_entries[n].e_uid =
103 make_kuid(&init_user_ns,
104 le32_to_cpu(entry->e_id));
105 break;
106 case ACL_GROUP:
107 value = (char *)value + sizeof(reiserfs_acl_entry);
108 if ((char *)value > end)
109 goto fail;
110 acl->a_entries[n].e_gid =
111 make_kgid(&init_user_ns,
112 le32_to_cpu(entry->e_id));
113 break;
114
115 default:
116 goto fail;
117 }
118 }
119 if (value != end)
120 goto fail;
121 return acl;
122
123 fail:
124 posix_acl_release(acl);
125 return ERR_PTR(-EINVAL);
126 }
127
128 /*
129 * Convert from in-memory to filesystem representation.
130 */
reiserfs_posix_acl_to_disk(const struct posix_acl * acl,size_t * size)131 static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
132 {
133 reiserfs_acl_header *ext_acl;
134 char *e;
135 int n;
136
137 *size = reiserfs_acl_size(acl->a_count);
138 ext_acl = kmalloc(sizeof(reiserfs_acl_header) +
139 acl->a_count *
140 sizeof(reiserfs_acl_entry),
141 GFP_NOFS);
142 if (!ext_acl)
143 return ERR_PTR(-ENOMEM);
144 ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
145 e = (char *)ext_acl + sizeof(reiserfs_acl_header);
146 for (n = 0; n < acl->a_count; n++) {
147 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
148 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
149 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
150 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
151 switch (acl->a_entries[n].e_tag) {
152 case ACL_USER:
153 entry->e_id = cpu_to_le32(
154 from_kuid(&init_user_ns, acl_e->e_uid));
155 e += sizeof(reiserfs_acl_entry);
156 break;
157 case ACL_GROUP:
158 entry->e_id = cpu_to_le32(
159 from_kgid(&init_user_ns, acl_e->e_gid));
160 e += sizeof(reiserfs_acl_entry);
161 break;
162
163 case ACL_USER_OBJ:
164 case ACL_GROUP_OBJ:
165 case ACL_MASK:
166 case ACL_OTHER:
167 e += sizeof(reiserfs_acl_entry_short);
168 break;
169
170 default:
171 goto fail;
172 }
173 }
174 return (char *)ext_acl;
175
176 fail:
177 kfree(ext_acl);
178 return ERR_PTR(-EINVAL);
179 }
180
181 /*
182 * Inode operation get_posix_acl().
183 *
184 * inode->i_mutex: down
185 * BKL held [before 2.5.x]
186 */
reiserfs_get_acl(struct inode * inode,int type)187 struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
188 {
189 char *name, *value;
190 struct posix_acl *acl;
191 int size;
192 int retval;
193
194 switch (type) {
195 case ACL_TYPE_ACCESS:
196 name = POSIX_ACL_XATTR_ACCESS;
197 break;
198 case ACL_TYPE_DEFAULT:
199 name = POSIX_ACL_XATTR_DEFAULT;
200 break;
201 default:
202 BUG();
203 }
204
205 size = reiserfs_xattr_get(inode, name, NULL, 0);
206 if (size < 0) {
207 if (size == -ENODATA || size == -ENOSYS) {
208 set_cached_acl(inode, type, NULL);
209 return NULL;
210 }
211 return ERR_PTR(size);
212 }
213
214 value = kmalloc(size, GFP_NOFS);
215 if (!value)
216 return ERR_PTR(-ENOMEM);
217
218 retval = reiserfs_xattr_get(inode, name, value, size);
219 if (retval == -ENODATA || retval == -ENOSYS) {
220 /*
221 * This shouldn't actually happen as it should have
222 * been caught above.. but just in case
223 */
224 acl = NULL;
225 } else if (retval < 0) {
226 acl = ERR_PTR(retval);
227 } else {
228 acl = reiserfs_posix_acl_from_disk(value, retval);
229 }
230 if (!IS_ERR(acl))
231 set_cached_acl(inode, type, acl);
232
233 kfree(value);
234 return acl;
235 }
236
237 /*
238 * Inode operation set_posix_acl().
239 *
240 * inode->i_mutex: down
241 * BKL held [before 2.5.x]
242 */
243 static int
__reiserfs_set_acl(struct reiserfs_transaction_handle * th,struct inode * inode,int type,struct posix_acl * acl)244 __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
245 int type, struct posix_acl *acl)
246 {
247 char *name;
248 void *value = NULL;
249 size_t size = 0;
250 int error;
251
252 switch (type) {
253 case ACL_TYPE_ACCESS:
254 name = POSIX_ACL_XATTR_ACCESS;
255 break;
256 case ACL_TYPE_DEFAULT:
257 name = POSIX_ACL_XATTR_DEFAULT;
258 if (!S_ISDIR(inode->i_mode))
259 return acl ? -EACCES : 0;
260 break;
261 default:
262 return -EINVAL;
263 }
264
265 if (acl) {
266 value = reiserfs_posix_acl_to_disk(acl, &size);
267 if (IS_ERR(value))
268 return (int)PTR_ERR(value);
269 }
270
271 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
272
273 /*
274 * Ensure that the inode gets dirtied if we're only using
275 * the mode bits and an old ACL didn't exist. We don't need
276 * to check if the inode is hashed here since we won't get
277 * called by reiserfs_inherit_default_acl().
278 */
279 if (error == -ENODATA) {
280 error = 0;
281 if (type == ACL_TYPE_ACCESS) {
282 inode->i_ctime = CURRENT_TIME_SEC;
283 mark_inode_dirty(inode);
284 }
285 }
286
287 kfree(value);
288
289 if (!error)
290 set_cached_acl(inode, type, acl);
291
292 return error;
293 }
294
295 /*
296 * dir->i_mutex: locked,
297 * inode is new and not released into the wild yet
298 */
299 int
reiserfs_inherit_default_acl(struct reiserfs_transaction_handle * th,struct inode * dir,struct dentry * dentry,struct inode * inode)300 reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
301 struct inode *dir, struct dentry *dentry,
302 struct inode *inode)
303 {
304 struct posix_acl *default_acl, *acl;
305 int err = 0;
306
307 /* ACLs only get applied to files and directories */
308 if (S_ISLNK(inode->i_mode))
309 return 0;
310
311 /*
312 * ACLs can only be used on "new" objects, so if it's an old object
313 * there is nothing to inherit from
314 */
315 if (get_inode_sd_version(dir) == STAT_DATA_V1)
316 goto apply_umask;
317
318 /*
319 * Don't apply ACLs to objects in the .reiserfs_priv tree.. This
320 * would be useless since permissions are ignored, and a pain because
321 * it introduces locking cycles
322 */
323 if (IS_PRIVATE(dir)) {
324 inode->i_flags |= S_PRIVATE;
325 goto apply_umask;
326 }
327
328 err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
329 if (err)
330 return err;
331
332 if (default_acl) {
333 err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
334 default_acl);
335 posix_acl_release(default_acl);
336 }
337 if (acl) {
338 if (!err)
339 err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS,
340 acl);
341 posix_acl_release(acl);
342 }
343
344 return err;
345
346 apply_umask:
347 /* no ACL, apply umask */
348 inode->i_mode &= ~current_umask();
349 return err;
350 }
351
352 /* This is used to cache the default acl before a new object is created.
353 * The biggest reason for this is to get an idea of how many blocks will
354 * actually be required for the create operation if we must inherit an ACL.
355 * An ACL write can add up to 3 object creations and an additional file write
356 * so we'd prefer not to reserve that many blocks in the journal if we can.
357 * It also has the advantage of not loading the ACL with a transaction open,
358 * this may seem silly, but if the owner of the directory is doing the
359 * creation, the ACL may not be loaded since the permissions wouldn't require
360 * it.
361 * We return the number of blocks required for the transaction.
362 */
reiserfs_cache_default_acl(struct inode * inode)363 int reiserfs_cache_default_acl(struct inode *inode)
364 {
365 struct posix_acl *acl;
366 int nblocks = 0;
367
368 if (IS_PRIVATE(inode))
369 return 0;
370
371 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
372
373 if (acl && !IS_ERR(acl)) {
374 int size = reiserfs_acl_size(acl->a_count);
375
376 /* Other xattrs can be created during inode creation. We don't
377 * want to claim too many blocks, so we check to see if we
378 * we need to create the tree to the xattrs, and then we
379 * just want two files. */
380 nblocks = reiserfs_xattr_jcreate_nblocks(inode);
381 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
382
383 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
384
385 /* We need to account for writes + bitmaps for two files */
386 nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
387 posix_acl_release(acl);
388 }
389
390 return nblocks;
391 }
392
393 /*
394 * Called under i_mutex
395 */
reiserfs_acl_chmod(struct inode * inode)396 int reiserfs_acl_chmod(struct inode *inode)
397 {
398 if (IS_PRIVATE(inode))
399 return 0;
400 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
401 !reiserfs_posixacl(inode->i_sb))
402 return 0;
403
404 return posix_acl_chmod(inode, inode->i_mode);
405 }
406