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

Archive Download this file



interactive