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 = XATTR_NAME_POSIX_ACL_ACCESS;
197 break;
198 case ACL_TYPE_DEFAULT:
199 name = XATTR_NAME_POSIX_ACL_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 return NULL;
209 return ERR_PTR(size);
210 }
211
212 value = kmalloc(size, GFP_NOFS);
213 if (!value)
214 return ERR_PTR(-ENOMEM);
215
216 retval = reiserfs_xattr_get(inode, name, value, size);
217 if (retval == -ENODATA || retval == -ENOSYS) {
218 /*
219 * This shouldn't actually happen as it should have
220 * been caught above.. but just in case
221 */
222 acl = NULL;
223 } else if (retval < 0) {
224 acl = ERR_PTR(retval);
225 } else {
226 acl = reiserfs_posix_acl_from_disk(value, retval);
227 }
228
229 kfree(value);
230 return acl;
231 }
232
233 /*
234 * Inode operation set_posix_acl().
235 *
236 * inode->i_mutex: down
237 * BKL held [before 2.5.x]
238 */
239 static int
__reiserfs_set_acl(struct reiserfs_transaction_handle * th,struct inode * inode,int type,struct posix_acl * acl)240 __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
241 int type, struct posix_acl *acl)
242 {
243 char *name;
244 void *value = NULL;
245 size_t size = 0;
246 int error;
247
248 switch (type) {
249 case ACL_TYPE_ACCESS:
250 name = XATTR_NAME_POSIX_ACL_ACCESS;
251 break;
252 case ACL_TYPE_DEFAULT:
253 name = XATTR_NAME_POSIX_ACL_DEFAULT;
254 if (!S_ISDIR(inode->i_mode))
255 return acl ? -EACCES : 0;
256 break;
257 default:
258 return -EINVAL;
259 }
260
261 if (acl) {
262 value = reiserfs_posix_acl_to_disk(acl, &size);
263 if (IS_ERR(value))
264 return (int)PTR_ERR(value);
265 }
266
267 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
268
269 /*
270 * Ensure that the inode gets dirtied if we're only using
271 * the mode bits and an old ACL didn't exist. We don't need
272 * to check if the inode is hashed here since we won't get
273 * called by reiserfs_inherit_default_acl().
274 */
275 if (error == -ENODATA) {
276 error = 0;
277 if (type == ACL_TYPE_ACCESS) {
278 inode->i_ctime = current_time(inode);
279 mark_inode_dirty(inode);
280 }
281 }
282
283 kfree(value);
284
285 if (!error)
286 set_cached_acl(inode, type, acl);
287
288 return error;
289 }
290
291 /*
292 * dir->i_mutex: locked,
293 * inode is new and not released into the wild yet
294 */
295 int
reiserfs_inherit_default_acl(struct reiserfs_transaction_handle * th,struct inode * dir,struct dentry * dentry,struct inode * inode)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 /*
308 * ACLs can only be used on "new" objects, so if it's an old object
309 * there is nothing to inherit from
310 */
311 if (get_inode_sd_version(dir) == STAT_DATA_V1)
312 goto apply_umask;
313
314 /*
315 * Don't apply ACLs to objects in the .reiserfs_priv tree.. This
316 * would be useless since permissions are ignored, and a pain because
317 * it introduces locking cycles
318 */
319 if (IS_PRIVATE(dir)) {
320 inode->i_flags |= S_PRIVATE;
321 goto apply_umask;
322 }
323
324 err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
325 if (err)
326 return err;
327
328 if (default_acl) {
329 err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
330 default_acl);
331 posix_acl_release(default_acl);
332 }
333 if (acl) {
334 if (!err)
335 err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS,
336 acl);
337 posix_acl_release(acl);
338 }
339
340 return err;
341
342 apply_umask:
343 /* no ACL, apply umask */
344 inode->i_mode &= ~current_umask();
345 return err;
346 }
347
348 /* This is used to cache the default acl before a new object is created.
349 * The biggest reason for this is to get an idea of how many blocks will
350 * actually be required for the create operation if we must inherit an ACL.
351 * An ACL write can add up to 3 object creations and an additional file write
352 * so we'd prefer not to reserve that many blocks in the journal if we can.
353 * It also has the advantage of not loading the ACL with a transaction open,
354 * this may seem silly, but if the owner of the directory is doing the
355 * creation, the ACL may not be loaded since the permissions wouldn't require
356 * it.
357 * We return the number of blocks required for the transaction.
358 */
reiserfs_cache_default_acl(struct inode * inode)359 int reiserfs_cache_default_acl(struct inode *inode)
360 {
361 struct posix_acl *acl;
362 int nblocks = 0;
363
364 if (IS_PRIVATE(inode))
365 return 0;
366
367 acl = get_acl(inode, ACL_TYPE_DEFAULT);
368
369 if (acl && !IS_ERR(acl)) {
370 int size = reiserfs_acl_size(acl->a_count);
371
372 /* Other xattrs can be created during inode creation. We don't
373 * want to claim too many blocks, so we check to see if we
374 * we need to create the tree to the xattrs, and then we
375 * just want two files. */
376 nblocks = reiserfs_xattr_jcreate_nblocks(inode);
377 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
378
379 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
380
381 /* We need to account for writes + bitmaps for two files */
382 nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
383 posix_acl_release(acl);
384 }
385
386 return nblocks;
387 }
388
389 /*
390 * Called under i_mutex
391 */
reiserfs_acl_chmod(struct inode * inode)392 int reiserfs_acl_chmod(struct inode *inode)
393 {
394 if (IS_PRIVATE(inode))
395 return 0;
396 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
397 !reiserfs_posixacl(inode->i_sb))
398 return 0;
399
400 return posix_acl_chmod(inode, inode->i_mode);
401 }
402