Root/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/slab.h>
25#include <linux/string.h>
26
27#include <cluster/masklog.h>
28
29#include "ocfs2.h"
30#include "alloc.h"
31#include "dlmglue.h"
32#include "file.h"
33#include "inode.h"
34#include "journal.h"
35#include "ocfs2_fs.h"
36
37#include "xattr.h"
38#include "acl.h"
39
40/*
41 * Convert from xattr value to acl struct.
42 */
43static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
44{
45    int n, count;
46    struct posix_acl *acl;
47
48    if (!value)
49        return NULL;
50    if (size < sizeof(struct posix_acl_entry))
51        return ERR_PTR(-EINVAL);
52
53    count = size / sizeof(struct posix_acl_entry);
54    if (count < 0)
55        return ERR_PTR(-EINVAL);
56    if (count == 0)
57        return NULL;
58
59    acl = posix_acl_alloc(count, GFP_NOFS);
60    if (!acl)
61        return ERR_PTR(-ENOMEM);
62    for (n = 0; n < count; n++) {
63        struct ocfs2_acl_entry *entry =
64            (struct ocfs2_acl_entry *)value;
65
66        acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
67        acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
68        acl->a_entries[n].e_id = le32_to_cpu(entry->e_id);
69        value += sizeof(struct posix_acl_entry);
70
71    }
72    return acl;
73}
74
75/*
76 * Convert acl struct to xattr value.
77 */
78static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
79{
80    struct ocfs2_acl_entry *entry = NULL;
81    char *ocfs2_acl;
82    size_t n;
83
84    *size = acl->a_count * sizeof(struct posix_acl_entry);
85
86    ocfs2_acl = kmalloc(*size, GFP_NOFS);
87    if (!ocfs2_acl)
88        return ERR_PTR(-ENOMEM);
89
90    entry = (struct ocfs2_acl_entry *)ocfs2_acl;
91    for (n = 0; n < acl->a_count; n++, entry++) {
92        entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
93        entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
94        entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
95    }
96    return ocfs2_acl;
97}
98
99static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
100                          int type,
101                          struct buffer_head *di_bh)
102{
103    int name_index;
104    char *value = NULL;
105    struct posix_acl *acl;
106    int retval;
107
108    switch (type) {
109    case ACL_TYPE_ACCESS:
110        name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
111        break;
112    case ACL_TYPE_DEFAULT:
113        name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
114        break;
115    default:
116        return ERR_PTR(-EINVAL);
117    }
118
119    retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
120    if (retval > 0) {
121        value = kmalloc(retval, GFP_NOFS);
122        if (!value)
123            return ERR_PTR(-ENOMEM);
124        retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
125                        "", value, retval);
126    }
127
128    if (retval > 0)
129        acl = ocfs2_acl_from_xattr(value, retval);
130    else if (retval == -ENODATA || retval == 0)
131        acl = NULL;
132    else
133        acl = ERR_PTR(retval);
134
135    kfree(value);
136
137    return acl;
138}
139
140
141/*
142 * Get posix acl.
143 */
144static struct posix_acl *ocfs2_get_acl(struct inode *inode, int type)
145{
146    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
147    struct buffer_head *di_bh = NULL;
148    struct posix_acl *acl;
149    int ret;
150
151    if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
152        return NULL;
153
154    ret = ocfs2_inode_lock(inode, &di_bh, 0);
155    if (ret < 0) {
156        mlog_errno(ret);
157        acl = ERR_PTR(ret);
158        return acl;
159    }
160
161    acl = ocfs2_get_acl_nolock(inode, type, di_bh);
162
163    ocfs2_inode_unlock(inode, 0);
164
165    brelse(di_bh);
166
167    return acl;
168}
169
170/*
171 * Helper function to set i_mode in memory and disk. Some call paths
172 * will not have di_bh or a journal handle to pass, in which case it
173 * will create it's own.
174 */
175static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
176                  handle_t *handle, umode_t new_mode)
177{
178    int ret, commit_handle = 0;
179    struct ocfs2_dinode *di;
180
181    if (di_bh == NULL) {
182        ret = ocfs2_read_inode_block(inode, &di_bh);
183        if (ret) {
184            mlog_errno(ret);
185            goto out;
186        }
187    } else
188        get_bh(di_bh);
189
190    if (handle == NULL) {
191        handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
192                       OCFS2_INODE_UPDATE_CREDITS);
193        if (IS_ERR(handle)) {
194            ret = PTR_ERR(handle);
195            mlog_errno(ret);
196            goto out_brelse;
197        }
198
199        commit_handle = 1;
200    }
201
202    di = (struct ocfs2_dinode *)di_bh->b_data;
203    ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
204                      OCFS2_JOURNAL_ACCESS_WRITE);
205    if (ret) {
206        mlog_errno(ret);
207        goto out_commit;
208    }
209
210    inode->i_mode = new_mode;
211    inode->i_ctime = CURRENT_TIME;
212    di->i_mode = cpu_to_le16(inode->i_mode);
213    di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
214    di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
215
216    ocfs2_journal_dirty(handle, di_bh);
217
218out_commit:
219    if (commit_handle)
220        ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
221out_brelse:
222    brelse(di_bh);
223out:
224    return ret;
225}
226
227/*
228 * Set the access or default ACL of an inode.
229 */
230static int ocfs2_set_acl(handle_t *handle,
231             struct inode *inode,
232             struct buffer_head *di_bh,
233             int type,
234             struct posix_acl *acl,
235             struct ocfs2_alloc_context *meta_ac,
236             struct ocfs2_alloc_context *data_ac)
237{
238    int name_index;
239    void *value = NULL;
240    size_t size = 0;
241    int ret;
242
243    if (S_ISLNK(inode->i_mode))
244        return -EOPNOTSUPP;
245
246    switch (type) {
247    case ACL_TYPE_ACCESS:
248        name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
249        if (acl) {
250            mode_t mode = inode->i_mode;
251            ret = posix_acl_equiv_mode(acl, &mode);
252            if (ret < 0)
253                return ret;
254            else {
255                if (ret == 0)
256                    acl = NULL;
257
258                ret = ocfs2_acl_set_mode(inode, di_bh,
259                             handle, mode);
260                if (ret)
261                    return ret;
262
263            }
264        }
265        break;
266    case ACL_TYPE_DEFAULT:
267        name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
268        if (!S_ISDIR(inode->i_mode))
269            return acl ? -EACCES : 0;
270        break;
271    default:
272        return -EINVAL;
273    }
274
275    if (acl) {
276        value = ocfs2_acl_to_xattr(acl, &size);
277        if (IS_ERR(value))
278            return (int)PTR_ERR(value);
279    }
280
281    if (handle)
282        ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
283                         "", value, size, 0,
284                         meta_ac, data_ac);
285    else
286        ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
287
288    kfree(value);
289
290    return ret;
291}
292
293int ocfs2_check_acl(struct inode *inode, int mask, unsigned int flags)
294{
295    struct ocfs2_super *osb;
296    struct buffer_head *di_bh = NULL;
297    struct posix_acl *acl;
298    int ret = -EAGAIN;
299
300    if (flags & IPERM_FLAG_RCU)
301        return -ECHILD;
302
303    osb = OCFS2_SB(inode->i_sb);
304    if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
305        return ret;
306
307    ret = ocfs2_read_inode_block(inode, &di_bh);
308    if (ret < 0) {
309        mlog_errno(ret);
310        return ret;
311    }
312
313    acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, di_bh);
314
315    brelse(di_bh);
316
317    if (IS_ERR(acl)) {
318        mlog_errno(PTR_ERR(acl));
319        return PTR_ERR(acl);
320    }
321    if (acl) {
322        ret = posix_acl_permission(inode, acl, mask);
323        posix_acl_release(acl);
324        return ret;
325    }
326
327    return -EAGAIN;
328}
329
330int ocfs2_acl_chmod(struct inode *inode)
331{
332    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
333    struct posix_acl *acl, *clone;
334    int ret;
335
336    if (S_ISLNK(inode->i_mode))
337        return -EOPNOTSUPP;
338
339    if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
340        return 0;
341
342    acl = ocfs2_get_acl(inode, ACL_TYPE_ACCESS);
343    if (IS_ERR(acl) || !acl)
344        return PTR_ERR(acl);
345    clone = posix_acl_clone(acl, GFP_KERNEL);
346    posix_acl_release(acl);
347    if (!clone)
348        return -ENOMEM;
349    ret = posix_acl_chmod_masq(clone, inode->i_mode);
350    if (!ret)
351        ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
352                    clone, NULL, NULL);
353    posix_acl_release(clone);
354    return ret;
355}
356
357/*
358 * Initialize the ACLs of a new inode. If parent directory has default ACL,
359 * then clone to new inode. Called from ocfs2_mknod.
360 */
361int ocfs2_init_acl(handle_t *handle,
362           struct inode *inode,
363           struct inode *dir,
364           struct buffer_head *di_bh,
365           struct buffer_head *dir_bh,
366           struct ocfs2_alloc_context *meta_ac,
367           struct ocfs2_alloc_context *data_ac)
368{
369    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
370    struct posix_acl *acl = NULL;
371    int ret = 0, ret2;
372    mode_t mode;
373
374    if (!S_ISLNK(inode->i_mode)) {
375        if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
376            acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
377                           dir_bh);
378            if (IS_ERR(acl))
379                return PTR_ERR(acl);
380        }
381        if (!acl) {
382            mode = inode->i_mode & ~current_umask();
383            ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
384            if (ret) {
385                mlog_errno(ret);
386                goto cleanup;
387            }
388        }
389    }
390    if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
391        struct posix_acl *clone;
392
393        if (S_ISDIR(inode->i_mode)) {
394            ret = ocfs2_set_acl(handle, inode, di_bh,
395                        ACL_TYPE_DEFAULT, acl,
396                        meta_ac, data_ac);
397            if (ret)
398                goto cleanup;
399        }
400        clone = posix_acl_clone(acl, GFP_NOFS);
401        ret = -ENOMEM;
402        if (!clone)
403            goto cleanup;
404
405        mode = inode->i_mode;
406        ret = posix_acl_create_masq(clone, &mode);
407        if (ret >= 0) {
408            ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
409            if (ret2) {
410                mlog_errno(ret2);
411                ret = ret2;
412                goto cleanup;
413            }
414            if (ret > 0) {
415                ret = ocfs2_set_acl(handle, inode,
416                            di_bh, ACL_TYPE_ACCESS,
417                            clone, meta_ac, data_ac);
418            }
419        }
420        posix_acl_release(clone);
421    }
422cleanup:
423    posix_acl_release(acl);
424    return ret;
425}
426
427static size_t ocfs2_xattr_list_acl_access(struct dentry *dentry,
428                      char *list,
429                      size_t list_len,
430                      const char *name,
431                      size_t name_len,
432                      int type)
433{
434    struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
435    const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
436
437    if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
438        return 0;
439
440    if (list && size <= list_len)
441        memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
442    return size;
443}
444
445static size_t ocfs2_xattr_list_acl_default(struct dentry *dentry,
446                       char *list,
447                       size_t list_len,
448                       const char *name,
449                       size_t name_len,
450                       int type)
451{
452    struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
453    const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
454
455    if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
456        return 0;
457
458    if (list && size <= list_len)
459        memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
460    return size;
461}
462
463static int ocfs2_xattr_get_acl(struct dentry *dentry, const char *name,
464        void *buffer, size_t size, int type)
465{
466    struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
467    struct posix_acl *acl;
468    int ret;
469
470    if (strcmp(name, "") != 0)
471        return -EINVAL;
472    if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
473        return -EOPNOTSUPP;
474
475    acl = ocfs2_get_acl(dentry->d_inode, type);
476    if (IS_ERR(acl))
477        return PTR_ERR(acl);
478    if (acl == NULL)
479        return -ENODATA;
480    ret = posix_acl_to_xattr(acl, buffer, size);
481    posix_acl_release(acl);
482
483    return ret;
484}
485
486static int ocfs2_xattr_set_acl(struct dentry *dentry, const char *name,
487        const void *value, size_t size, int flags, int type)
488{
489    struct inode *inode = dentry->d_inode;
490    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
491    struct posix_acl *acl;
492    int ret = 0;
493
494    if (strcmp(name, "") != 0)
495        return -EINVAL;
496    if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
497        return -EOPNOTSUPP;
498
499    if (!inode_owner_or_capable(inode))
500        return -EPERM;
501
502    if (value) {
503        acl = posix_acl_from_xattr(value, size);
504        if (IS_ERR(acl))
505            return PTR_ERR(acl);
506        else if (acl) {
507            ret = posix_acl_valid(acl);
508            if (ret)
509                goto cleanup;
510        }
511    } else
512        acl = NULL;
513
514    ret = ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
515
516cleanup:
517    posix_acl_release(acl);
518    return ret;
519}
520
521const struct xattr_handler ocfs2_xattr_acl_access_handler = {
522    .prefix = POSIX_ACL_XATTR_ACCESS,
523    .flags = ACL_TYPE_ACCESS,
524    .list = ocfs2_xattr_list_acl_access,
525    .get = ocfs2_xattr_get_acl,
526    .set = ocfs2_xattr_set_acl,
527};
528
529const struct xattr_handler ocfs2_xattr_acl_default_handler = {
530    .prefix = POSIX_ACL_XATTR_DEFAULT,
531    .flags = ACL_TYPE_DEFAULT,
532    .list = ocfs2_xattr_list_acl_default,
533    .get = ocfs2_xattr_get_acl,
534    .set = ocfs2_xattr_set_acl,
535};
536

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