xref: /kernel/linux/linux-5.10/fs/ocfs2/acl.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-only
2/* -*- mode: c; c-basic-offset: 8; -*-
3 * vim: noexpandtab sw=8 ts=8 sts=0:
4 *
5 * acl.c
6 *
7 * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
8 *
9 * CREDITS:
10 * Lots of code in this file is copy from linux/fs/ext3/acl.c.
11 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
12 */
13
14#include <linux/init.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/string.h>
18
19#include <cluster/masklog.h>
20
21#include "ocfs2.h"
22#include "alloc.h"
23#include "dlmglue.h"
24#include "file.h"
25#include "inode.h"
26#include "journal.h"
27#include "ocfs2_fs.h"
28
29#include "xattr.h"
30#include "acl.h"
31
32/*
33 * Convert from xattr value to acl struct.
34 */
35static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
36{
37	int n, count;
38	struct posix_acl *acl;
39
40	if (!value)
41		return NULL;
42	if (size < sizeof(struct posix_acl_entry))
43		return ERR_PTR(-EINVAL);
44
45	count = size / sizeof(struct posix_acl_entry);
46
47	acl = posix_acl_alloc(count, GFP_NOFS);
48	if (!acl)
49		return ERR_PTR(-ENOMEM);
50	for (n = 0; n < count; n++) {
51		struct ocfs2_acl_entry *entry =
52			(struct ocfs2_acl_entry *)value;
53
54		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
55		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
56		switch(acl->a_entries[n].e_tag) {
57		case ACL_USER:
58			acl->a_entries[n].e_uid =
59				make_kuid(&init_user_ns,
60					  le32_to_cpu(entry->e_id));
61			break;
62		case ACL_GROUP:
63			acl->a_entries[n].e_gid =
64				make_kgid(&init_user_ns,
65					  le32_to_cpu(entry->e_id));
66			break;
67		default:
68			break;
69		}
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		switch(acl->a_entries[n].e_tag) {
96		case ACL_USER:
97			entry->e_id = cpu_to_le32(
98				from_kuid(&init_user_ns,
99					  acl->a_entries[n].e_uid));
100			break;
101		case ACL_GROUP:
102			entry->e_id = cpu_to_le32(
103				from_kgid(&init_user_ns,
104					  acl->a_entries[n].e_gid));
105			break;
106		default:
107			entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
108			break;
109		}
110	}
111	return ocfs2_acl;
112}
113
114static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
115					      int type,
116					      struct buffer_head *di_bh)
117{
118	int name_index;
119	char *value = NULL;
120	struct posix_acl *acl;
121	int retval;
122
123	switch (type) {
124	case ACL_TYPE_ACCESS:
125		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
126		break;
127	case ACL_TYPE_DEFAULT:
128		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
129		break;
130	default:
131		return ERR_PTR(-EINVAL);
132	}
133
134	retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
135	if (retval > 0) {
136		value = kmalloc(retval, GFP_NOFS);
137		if (!value)
138			return ERR_PTR(-ENOMEM);
139		retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
140						"", value, retval);
141	}
142
143	if (retval > 0)
144		acl = ocfs2_acl_from_xattr(value, retval);
145	else if (retval == -ENODATA || retval == 0)
146		acl = NULL;
147	else
148		acl = ERR_PTR(retval);
149
150	kfree(value);
151
152	return acl;
153}
154
155/*
156 * Helper function to set i_mode in memory and disk. Some call paths
157 * will not have di_bh or a journal handle to pass, in which case it
158 * will create it's own.
159 */
160static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
161			      handle_t *handle, umode_t new_mode)
162{
163	int ret, commit_handle = 0;
164	struct ocfs2_dinode *di;
165
166	if (di_bh == NULL) {
167		ret = ocfs2_read_inode_block(inode, &di_bh);
168		if (ret) {
169			mlog_errno(ret);
170			goto out;
171		}
172	} else
173		get_bh(di_bh);
174
175	if (handle == NULL) {
176		handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
177					   OCFS2_INODE_UPDATE_CREDITS);
178		if (IS_ERR(handle)) {
179			ret = PTR_ERR(handle);
180			mlog_errno(ret);
181			goto out_brelse;
182		}
183
184		commit_handle = 1;
185	}
186
187	di = (struct ocfs2_dinode *)di_bh->b_data;
188	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
189				      OCFS2_JOURNAL_ACCESS_WRITE);
190	if (ret) {
191		mlog_errno(ret);
192		goto out_commit;
193	}
194
195	inode->i_mode = new_mode;
196	inode->i_ctime = current_time(inode);
197	di->i_mode = cpu_to_le16(inode->i_mode);
198	di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
199	di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
200	ocfs2_update_inode_fsync_trans(handle, inode, 0);
201
202	ocfs2_journal_dirty(handle, di_bh);
203
204out_commit:
205	if (commit_handle)
206		ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
207out_brelse:
208	brelse(di_bh);
209out:
210	return ret;
211}
212
213/*
214 * Set the access or default ACL of an inode.
215 */
216static int ocfs2_set_acl(handle_t *handle,
217			 struct inode *inode,
218			 struct buffer_head *di_bh,
219			 int type,
220			 struct posix_acl *acl,
221			 struct ocfs2_alloc_context *meta_ac,
222			 struct ocfs2_alloc_context *data_ac)
223{
224	int name_index;
225	void *value = NULL;
226	size_t size = 0;
227	int ret;
228
229	if (S_ISLNK(inode->i_mode))
230		return -EOPNOTSUPP;
231
232	switch (type) {
233	case ACL_TYPE_ACCESS:
234		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
235		break;
236	case ACL_TYPE_DEFAULT:
237		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
238		if (!S_ISDIR(inode->i_mode))
239			return acl ? -EACCES : 0;
240		break;
241	default:
242		return -EINVAL;
243	}
244
245	if (acl) {
246		value = ocfs2_acl_to_xattr(acl, &size);
247		if (IS_ERR(value))
248			return (int)PTR_ERR(value);
249	}
250
251	if (handle)
252		ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
253					     "", value, size, 0,
254					     meta_ac, data_ac);
255	else
256		ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
257
258	kfree(value);
259	if (!ret)
260		set_cached_acl(inode, type, acl);
261
262	return ret;
263}
264
265int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, int type)
266{
267	struct buffer_head *bh = NULL;
268	int status, had_lock;
269	struct ocfs2_lock_holder oh;
270
271	had_lock = ocfs2_inode_lock_tracker(inode, &bh, 1, &oh);
272	if (had_lock < 0)
273		return had_lock;
274	if (type == ACL_TYPE_ACCESS && acl) {
275		umode_t mode;
276
277		status = posix_acl_update_mode(inode, &mode, &acl);
278		if (status)
279			goto unlock;
280
281		status = ocfs2_acl_set_mode(inode, bh, NULL, mode);
282		if (status)
283			goto unlock;
284	}
285	status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
286unlock:
287	ocfs2_inode_unlock_tracker(inode, 1, &oh, had_lock);
288	brelse(bh);
289	return status;
290}
291
292struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
293{
294	struct ocfs2_super *osb;
295	struct buffer_head *di_bh = NULL;
296	struct posix_acl *acl;
297	int had_lock;
298	struct ocfs2_lock_holder oh;
299
300	osb = OCFS2_SB(inode->i_sb);
301	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
302		return NULL;
303
304	had_lock = ocfs2_inode_lock_tracker(inode, &di_bh, 0, &oh);
305	if (had_lock < 0)
306		return ERR_PTR(had_lock);
307
308	down_read(&OCFS2_I(inode)->ip_xattr_sem);
309	acl = ocfs2_get_acl_nolock(inode, type, di_bh);
310	up_read(&OCFS2_I(inode)->ip_xattr_sem);
311
312	ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
313	brelse(di_bh);
314	return acl;
315}
316
317int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
318{
319	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
320	struct posix_acl *acl;
321	int ret;
322
323	if (S_ISLNK(inode->i_mode))
324		return -EOPNOTSUPP;
325
326	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
327		return 0;
328
329	down_read(&OCFS2_I(inode)->ip_xattr_sem);
330	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
331	up_read(&OCFS2_I(inode)->ip_xattr_sem);
332	if (IS_ERR_OR_NULL(acl))
333		return PTR_ERR_OR_ZERO(acl);
334	ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
335	if (ret)
336		return ret;
337	ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
338			    acl, NULL, NULL);
339	posix_acl_release(acl);
340	return ret;
341}
342
343/*
344 * Initialize the ACLs of a new inode. If parent directory has default ACL,
345 * then clone to new inode. Called from ocfs2_mknod.
346 */
347int ocfs2_init_acl(handle_t *handle,
348		   struct inode *inode,
349		   struct inode *dir,
350		   struct buffer_head *di_bh,
351		   struct buffer_head *dir_bh,
352		   struct ocfs2_alloc_context *meta_ac,
353		   struct ocfs2_alloc_context *data_ac)
354{
355	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
356	struct posix_acl *acl = NULL;
357	int ret = 0, ret2;
358	umode_t mode;
359
360	if (!S_ISLNK(inode->i_mode)) {
361		if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
362			down_read(&OCFS2_I(dir)->ip_xattr_sem);
363			acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
364						   dir_bh);
365			up_read(&OCFS2_I(dir)->ip_xattr_sem);
366			if (IS_ERR(acl))
367				return PTR_ERR(acl);
368		}
369		if (!acl) {
370			mode = inode->i_mode & ~current_umask();
371			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
372			if (ret) {
373				mlog_errno(ret);
374				goto cleanup;
375			}
376		}
377	}
378	if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
379		if (S_ISDIR(inode->i_mode)) {
380			ret = ocfs2_set_acl(handle, inode, di_bh,
381					    ACL_TYPE_DEFAULT, acl,
382					    meta_ac, data_ac);
383			if (ret)
384				goto cleanup;
385		}
386		mode = inode->i_mode;
387		ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
388		if (ret < 0)
389			return ret;
390
391		ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
392		if (ret2) {
393			mlog_errno(ret2);
394			ret = ret2;
395			goto cleanup;
396		}
397		if (ret > 0) {
398			ret = ocfs2_set_acl(handle, inode,
399					    di_bh, ACL_TYPE_ACCESS,
400					    acl, meta_ac, data_ac);
401		}
402	}
403cleanup:
404	posix_acl_release(acl);
405	return ret;
406}
407