Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6] / fs / ocfs2 / acl.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * acl.c
5  *
6  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
7  *
8  * CREDITS:
9  * Lots of code in this file is copy from linux/fs/ext3/acl.c.
10  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public
14  * License version 2 as published by the Free Software Foundation.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * General Public License for more details.
20  */
21
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/string.h>
25
26 #define MLOG_MASK_PREFIX ML_INODE
27 #include <cluster/masklog.h>
28
29 #include "ocfs2.h"
30 #include "alloc.h"
31 #include "dlmglue.h"
32 #include "file.h"
33 #include "ocfs2_fs.h"
34
35 #include "xattr.h"
36 #include "acl.h"
37
38 /*
39  * Convert from xattr value to acl struct.
40  */
41 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
42 {
43         int n, count;
44         struct posix_acl *acl;
45
46         if (!value)
47                 return NULL;
48         if (size < sizeof(struct posix_acl_entry))
49                 return ERR_PTR(-EINVAL);
50
51         count = size / sizeof(struct posix_acl_entry);
52         if (count < 0)
53                 return ERR_PTR(-EINVAL);
54         if (count == 0)
55                 return NULL;
56
57         acl = posix_acl_alloc(count, GFP_NOFS);
58         if (!acl)
59                 return ERR_PTR(-ENOMEM);
60         for (n = 0; n < count; n++) {
61                 struct ocfs2_acl_entry *entry =
62                         (struct ocfs2_acl_entry *)value;
63
64                 acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
65                 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
66                 acl->a_entries[n].e_id   = le32_to_cpu(entry->e_id);
67                 value += sizeof(struct posix_acl_entry);
68
69         }
70         return acl;
71 }
72
73 /*
74  * Convert acl struct to xattr value.
75  */
76 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
77 {
78         struct ocfs2_acl_entry *entry = NULL;
79         char *ocfs2_acl;
80         size_t n;
81
82         *size = acl->a_count * sizeof(struct posix_acl_entry);
83
84         ocfs2_acl = kmalloc(*size, GFP_NOFS);
85         if (!ocfs2_acl)
86                 return ERR_PTR(-ENOMEM);
87
88         entry = (struct ocfs2_acl_entry *)ocfs2_acl;
89         for (n = 0; n < acl->a_count; n++, entry++) {
90                 entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
91                 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
92                 entry->e_id   = cpu_to_le32(acl->a_entries[n].e_id);
93         }
94         return ocfs2_acl;
95 }
96
97 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
98                                               int type,
99                                               struct buffer_head *di_bh)
100 {
101         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
102         int name_index;
103         char *value = NULL;
104         struct posix_acl *acl;
105         int retval;
106
107         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
108                 return NULL;
109
110         switch (type) {
111         case ACL_TYPE_ACCESS:
112                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
113                 break;
114         case ACL_TYPE_DEFAULT:
115                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
116                 break;
117         default:
118                 return ERR_PTR(-EINVAL);
119         }
120
121         retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
122         if (retval > 0) {
123                 value = kmalloc(retval, GFP_NOFS);
124                 if (!value)
125                         return ERR_PTR(-ENOMEM);
126                 retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
127                                                 "", value, retval);
128         }
129
130         if (retval > 0)
131                 acl = ocfs2_acl_from_xattr(value, retval);
132         else if (retval == -ENODATA || retval == 0)
133                 acl = NULL;
134         else
135                 acl = ERR_PTR(retval);
136
137         kfree(value);
138
139         return acl;
140 }
141
142
143 /*
144  * Get posix acl.
145  */
146 static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
147 {
148         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
149         struct buffer_head *di_bh = NULL;
150         struct posix_acl *acl;
151         int ret;
152
153         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
154                 return NULL;
155
156         ret = ocfs2_inode_lock(inode, &di_bh, 0);
157         if (ret < 0) {
158                 mlog_errno(ret);
159                 acl = ERR_PTR(ret);
160                 return acl;
161         }
162
163         acl = ocfs2_get_acl_nolock(inode, type, di_bh);
164
165         ocfs2_inode_unlock(inode, 0);
166
167         brelse(di_bh);
168
169         return acl;
170 }
171
172 /*
173  * Set the access or default ACL of an inode.
174  */
175 static int ocfs2_set_acl(handle_t *handle,
176                          struct inode *inode,
177                          struct buffer_head *di_bh,
178                          int type,
179                          struct posix_acl *acl,
180                          struct ocfs2_alloc_context *meta_ac,
181                          struct ocfs2_alloc_context *data_ac)
182 {
183         int name_index;
184         void *value = NULL;
185         size_t size = 0;
186         int ret;
187
188         if (S_ISLNK(inode->i_mode))
189                 return -EOPNOTSUPP;
190
191         switch (type) {
192         case ACL_TYPE_ACCESS:
193                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
194                 if (acl) {
195                         mode_t mode = inode->i_mode;
196                         ret = posix_acl_equiv_mode(acl, &mode);
197                         if (ret < 0)
198                                 return ret;
199                         else {
200                                 inode->i_mode = mode;
201                                 if (ret == 0)
202                                         acl = NULL;
203                         }
204                 }
205                 break;
206         case ACL_TYPE_DEFAULT:
207                 name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
208                 if (!S_ISDIR(inode->i_mode))
209                         return acl ? -EACCES : 0;
210                 break;
211         default:
212                 return -EINVAL;
213         }
214
215         if (acl) {
216                 value = ocfs2_acl_to_xattr(acl, &size);
217                 if (IS_ERR(value))
218                         return (int)PTR_ERR(value);
219         }
220
221         if (handle)
222                 ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
223                                              "", value, size, 0,
224                                              meta_ac, data_ac);
225         else
226                 ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
227
228         kfree(value);
229
230         return ret;
231 }
232
233 int ocfs2_check_acl(struct inode *inode, int mask)
234 {
235         struct posix_acl *acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
236
237         if (IS_ERR(acl))
238                 return PTR_ERR(acl);
239         if (acl) {
240                 int ret = posix_acl_permission(inode, acl, mask);
241                 posix_acl_release(acl);
242                 return ret;
243         }
244
245         return -EAGAIN;
246 }
247
248 int ocfs2_acl_chmod(struct inode *inode)
249 {
250         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
251         struct posix_acl *acl, *clone;
252         int ret;
253
254         if (S_ISLNK(inode->i_mode))
255                 return -EOPNOTSUPP;
256
257         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
258                 return 0;
259
260         acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
261         if (IS_ERR(acl) || !acl)
262                 return PTR_ERR(acl);
263         clone = posix_acl_clone(acl, GFP_KERNEL);
264         posix_acl_release(acl);
265         if (!clone)
266                 return -ENOMEM;
267         ret = posix_acl_chmod_masq(clone, inode->i_mode);
268         if (!ret)
269                 ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
270                                     clone, NULL, NULL);
271         posix_acl_release(clone);
272         return ret;
273 }
274
275 /*
276  * Initialize the ACLs of a new inode. If parent directory has default ACL,
277  * then clone to new inode. Called from ocfs2_mknod.
278  */
279 int ocfs2_init_acl(handle_t *handle,
280                    struct inode *inode,
281                    struct inode *dir,
282                    struct buffer_head *di_bh,
283                    struct buffer_head *dir_bh,
284                    struct ocfs2_alloc_context *meta_ac,
285                    struct ocfs2_alloc_context *data_ac)
286 {
287         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
288         struct posix_acl *acl = NULL;
289         int ret = 0;
290
291         if (!S_ISLNK(inode->i_mode)) {
292                 if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
293                         acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
294                                                    dir_bh);
295                         if (IS_ERR(acl))
296                                 return PTR_ERR(acl);
297                 }
298                 if (!acl)
299                         inode->i_mode &= ~current_umask();
300         }
301         if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
302                 struct posix_acl *clone;
303                 mode_t mode;
304
305                 if (S_ISDIR(inode->i_mode)) {
306                         ret = ocfs2_set_acl(handle, inode, di_bh,
307                                             ACL_TYPE_DEFAULT, acl,
308                                             meta_ac, data_ac);
309                         if (ret)
310                                 goto cleanup;
311                 }
312                 clone = posix_acl_clone(acl, GFP_NOFS);
313                 ret = -ENOMEM;
314                 if (!clone)
315                         goto cleanup;
316
317                 mode = inode->i_mode;
318                 ret = posix_acl_create_masq(clone, &mode);
319                 if (ret >= 0) {
320                         inode->i_mode = mode;
321                         if (ret > 0) {
322                                 ret = ocfs2_set_acl(handle, inode,
323                                                     di_bh, ACL_TYPE_ACCESS,
324                                                     clone, meta_ac, data_ac);
325                         }
326                 }
327                 posix_acl_release(clone);
328         }
329 cleanup:
330         posix_acl_release(acl);
331         return ret;
332 }
333
334 static size_t ocfs2_xattr_list_acl_access(struct inode *inode,
335                                           char *list,
336                                           size_t list_len,
337                                           const char *name,
338                                           size_t name_len)
339 {
340         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
341         const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
342
343         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
344                 return 0;
345
346         if (list && size <= list_len)
347                 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
348         return size;
349 }
350
351 static size_t ocfs2_xattr_list_acl_default(struct inode *inode,
352                                            char *list,
353                                            size_t list_len,
354                                            const char *name,
355                                            size_t name_len)
356 {
357         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
358         const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
359
360         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
361                 return 0;
362
363         if (list && size <= list_len)
364                 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
365         return size;
366 }
367
368 static int ocfs2_xattr_get_acl(struct inode *inode,
369                                int type,
370                                void *buffer,
371                                size_t size)
372 {
373         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
374         struct posix_acl *acl;
375         int ret;
376
377         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
378                 return -EOPNOTSUPP;
379
380         acl = ocfs2_get_acl(inode, type);
381         if (IS_ERR(acl))
382                 return PTR_ERR(acl);
383         if (acl == NULL)
384                 return -ENODATA;
385         ret = posix_acl_to_xattr(acl, buffer, size);
386         posix_acl_release(acl);
387
388         return ret;
389 }
390
391 static int ocfs2_xattr_get_acl_access(struct inode *inode,
392                                       const char *name,
393                                       void *buffer,
394                                       size_t size)
395 {
396         if (strcmp(name, "") != 0)
397                 return -EINVAL;
398         return ocfs2_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
399 }
400
401 static int ocfs2_xattr_get_acl_default(struct inode *inode,
402                                        const char *name,
403                                        void *buffer,
404                                        size_t size)
405 {
406         if (strcmp(name, "") != 0)
407                 return -EINVAL;
408         return ocfs2_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
409 }
410
411 static int ocfs2_xattr_set_acl(struct inode *inode,
412                                int type,
413                                const void *value,
414                                size_t size)
415 {
416         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
417         struct posix_acl *acl;
418         int ret = 0;
419
420         if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
421                 return -EOPNOTSUPP;
422
423         if (!is_owner_or_cap(inode))
424                 return -EPERM;
425
426         if (value) {
427                 acl = posix_acl_from_xattr(value, size);
428                 if (IS_ERR(acl))
429                         return PTR_ERR(acl);
430                 else if (acl) {
431                         ret = posix_acl_valid(acl);
432                         if (ret)
433                                 goto cleanup;
434                 }
435         } else
436                 acl = NULL;
437
438         ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
439
440 cleanup:
441         posix_acl_release(acl);
442         return ret;
443 }
444
445 static int ocfs2_xattr_set_acl_access(struct inode *inode,
446                                       const char *name,
447                                       const void *value,
448                                       size_t size,
449                                       int flags)
450 {
451         if (strcmp(name, "") != 0)
452                 return -EINVAL;
453         return ocfs2_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
454 }
455
456 static int ocfs2_xattr_set_acl_default(struct inode *inode,
457                                        const char *name,
458                                        const void *value,
459                                        size_t size,
460                                        int flags)
461 {
462         if (strcmp(name, "") != 0)
463                 return -EINVAL;
464         return ocfs2_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
465 }
466
467 struct xattr_handler ocfs2_xattr_acl_access_handler = {
468         .prefix = POSIX_ACL_XATTR_ACCESS,
469         .list   = ocfs2_xattr_list_acl_access,
470         .get    = ocfs2_xattr_get_acl_access,
471         .set    = ocfs2_xattr_set_acl_access,
472 };
473
474 struct xattr_handler ocfs2_xattr_acl_default_handler = {
475         .prefix = POSIX_ACL_XATTR_DEFAULT,
476         .list   = ocfs2_xattr_list_acl_default,
477         .get    = ocfs2_xattr_get_acl_default,
478         .set    = ocfs2_xattr_set_acl_default,
479 };