xref: /openbmc/linux/fs/ocfs2/acl.c (revision e29dc460)
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  */
43 static 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 
55 	acl = posix_acl_alloc(count, GFP_NOFS);
56 	if (!acl)
57 		return ERR_PTR(-ENOMEM);
58 	for (n = 0; n < count; n++) {
59 		struct ocfs2_acl_entry *entry =
60 			(struct ocfs2_acl_entry *)value;
61 
62 		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
63 		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
64 		switch(acl->a_entries[n].e_tag) {
65 		case ACL_USER:
66 			acl->a_entries[n].e_uid =
67 				make_kuid(&init_user_ns,
68 					  le32_to_cpu(entry->e_id));
69 			break;
70 		case ACL_GROUP:
71 			acl->a_entries[n].e_gid =
72 				make_kgid(&init_user_ns,
73 					  le32_to_cpu(entry->e_id));
74 			break;
75 		default:
76 			break;
77 		}
78 		value += sizeof(struct posix_acl_entry);
79 
80 	}
81 	return acl;
82 }
83 
84 /*
85  * Convert acl struct to xattr value.
86  */
87 static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
88 {
89 	struct ocfs2_acl_entry *entry = NULL;
90 	char *ocfs2_acl;
91 	size_t n;
92 
93 	*size = acl->a_count * sizeof(struct posix_acl_entry);
94 
95 	ocfs2_acl = kmalloc(*size, GFP_NOFS);
96 	if (!ocfs2_acl)
97 		return ERR_PTR(-ENOMEM);
98 
99 	entry = (struct ocfs2_acl_entry *)ocfs2_acl;
100 	for (n = 0; n < acl->a_count; n++, entry++) {
101 		entry->e_tag  = cpu_to_le16(acl->a_entries[n].e_tag);
102 		entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
103 		switch(acl->a_entries[n].e_tag) {
104 		case ACL_USER:
105 			entry->e_id = cpu_to_le32(
106 				from_kuid(&init_user_ns,
107 					  acl->a_entries[n].e_uid));
108 			break;
109 		case ACL_GROUP:
110 			entry->e_id = cpu_to_le32(
111 				from_kgid(&init_user_ns,
112 					  acl->a_entries[n].e_gid));
113 			break;
114 		default:
115 			entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
116 			break;
117 		}
118 	}
119 	return ocfs2_acl;
120 }
121 
122 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
123 					      int type,
124 					      struct buffer_head *di_bh)
125 {
126 	int name_index;
127 	char *value = NULL;
128 	struct posix_acl *acl;
129 	int retval;
130 
131 	switch (type) {
132 	case ACL_TYPE_ACCESS:
133 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
134 		break;
135 	case ACL_TYPE_DEFAULT:
136 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
137 		break;
138 	default:
139 		return ERR_PTR(-EINVAL);
140 	}
141 
142 	retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
143 	if (retval > 0) {
144 		value = kmalloc(retval, GFP_NOFS);
145 		if (!value)
146 			return ERR_PTR(-ENOMEM);
147 		retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
148 						"", value, retval);
149 	}
150 
151 	if (retval > 0)
152 		acl = ocfs2_acl_from_xattr(value, retval);
153 	else if (retval == -ENODATA || retval == 0)
154 		acl = NULL;
155 	else
156 		acl = ERR_PTR(retval);
157 
158 	kfree(value);
159 
160 	return acl;
161 }
162 
163 /*
164  * Helper function to set i_mode in memory and disk. Some call paths
165  * will not have di_bh or a journal handle to pass, in which case it
166  * will create it's own.
167  */
168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
169 			      handle_t *handle, umode_t new_mode)
170 {
171 	int ret, commit_handle = 0;
172 	struct ocfs2_dinode *di;
173 
174 	if (di_bh == NULL) {
175 		ret = ocfs2_read_inode_block(inode, &di_bh);
176 		if (ret) {
177 			mlog_errno(ret);
178 			goto out;
179 		}
180 	} else
181 		get_bh(di_bh);
182 
183 	if (handle == NULL) {
184 		handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
185 					   OCFS2_INODE_UPDATE_CREDITS);
186 		if (IS_ERR(handle)) {
187 			ret = PTR_ERR(handle);
188 			mlog_errno(ret);
189 			goto out_brelse;
190 		}
191 
192 		commit_handle = 1;
193 	}
194 
195 	di = (struct ocfs2_dinode *)di_bh->b_data;
196 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
197 				      OCFS2_JOURNAL_ACCESS_WRITE);
198 	if (ret) {
199 		mlog_errno(ret);
200 		goto out_commit;
201 	}
202 
203 	inode->i_mode = new_mode;
204 	inode->i_ctime = current_time(inode);
205 	di->i_mode = cpu_to_le16(inode->i_mode);
206 	di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
207 	di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
208 	ocfs2_update_inode_fsync_trans(handle, inode, 0);
209 
210 	ocfs2_journal_dirty(handle, di_bh);
211 
212 out_commit:
213 	if (commit_handle)
214 		ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
215 out_brelse:
216 	brelse(di_bh);
217 out:
218 	return ret;
219 }
220 
221 /*
222  * Set the access or default ACL of an inode.
223  */
224 static int ocfs2_set_acl(handle_t *handle,
225 			 struct inode *inode,
226 			 struct buffer_head *di_bh,
227 			 int type,
228 			 struct posix_acl *acl,
229 			 struct ocfs2_alloc_context *meta_ac,
230 			 struct ocfs2_alloc_context *data_ac)
231 {
232 	int name_index;
233 	void *value = NULL;
234 	size_t size = 0;
235 	int ret;
236 
237 	if (S_ISLNK(inode->i_mode))
238 		return -EOPNOTSUPP;
239 
240 	switch (type) {
241 	case ACL_TYPE_ACCESS:
242 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
243 		break;
244 	case ACL_TYPE_DEFAULT:
245 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
246 		if (!S_ISDIR(inode->i_mode))
247 			return acl ? -EACCES : 0;
248 		break;
249 	default:
250 		return -EINVAL;
251 	}
252 
253 	if (acl) {
254 		value = ocfs2_acl_to_xattr(acl, &size);
255 		if (IS_ERR(value))
256 			return (int)PTR_ERR(value);
257 	}
258 
259 	if (handle)
260 		ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
261 					     "", value, size, 0,
262 					     meta_ac, data_ac);
263 	else
264 		ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
265 
266 	kfree(value);
267 
268 	return ret;
269 }
270 
271 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, int type)
272 {
273 	struct buffer_head *bh = NULL;
274 	int status, had_lock;
275 	struct ocfs2_lock_holder oh;
276 
277 	had_lock = ocfs2_inode_lock_tracker(inode, &bh, 1, &oh);
278 	if (had_lock < 0)
279 		return had_lock;
280 	if (type == ACL_TYPE_ACCESS && acl) {
281 		umode_t mode;
282 
283 		status = posix_acl_update_mode(inode, &mode, &acl);
284 		if (status)
285 			goto unlock;
286 
287 		status = ocfs2_acl_set_mode(inode, bh, NULL, mode);
288 		if (status)
289 			goto unlock;
290 	}
291 	status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
292 unlock:
293 	ocfs2_inode_unlock_tracker(inode, 1, &oh, had_lock);
294 	brelse(bh);
295 	return status;
296 }
297 
298 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
299 {
300 	struct ocfs2_super *osb;
301 	struct buffer_head *di_bh = NULL;
302 	struct posix_acl *acl;
303 	int had_lock;
304 	struct ocfs2_lock_holder oh;
305 
306 	osb = OCFS2_SB(inode->i_sb);
307 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
308 		return NULL;
309 
310 	had_lock = ocfs2_inode_lock_tracker(inode, &di_bh, 0, &oh);
311 	if (had_lock < 0)
312 		return ERR_PTR(had_lock);
313 
314 	down_read(&OCFS2_I(inode)->ip_xattr_sem);
315 	acl = ocfs2_get_acl_nolock(inode, type, di_bh);
316 	up_read(&OCFS2_I(inode)->ip_xattr_sem);
317 
318 	ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
319 	brelse(di_bh);
320 	return acl;
321 }
322 
323 int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
324 {
325 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
326 	struct posix_acl *acl;
327 	int ret;
328 
329 	if (S_ISLNK(inode->i_mode))
330 		return -EOPNOTSUPP;
331 
332 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
333 		return 0;
334 
335 	down_read(&OCFS2_I(inode)->ip_xattr_sem);
336 	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
337 	up_read(&OCFS2_I(inode)->ip_xattr_sem);
338 	if (IS_ERR(acl) || !acl)
339 		return PTR_ERR(acl);
340 	ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
341 	if (ret)
342 		return ret;
343 	ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
344 			    acl, NULL, NULL);
345 	posix_acl_release(acl);
346 	return ret;
347 }
348 
349 /*
350  * Initialize the ACLs of a new inode. If parent directory has default ACL,
351  * then clone to new inode. Called from ocfs2_mknod.
352  */
353 int ocfs2_init_acl(handle_t *handle,
354 		   struct inode *inode,
355 		   struct inode *dir,
356 		   struct buffer_head *di_bh,
357 		   struct buffer_head *dir_bh,
358 		   struct ocfs2_alloc_context *meta_ac,
359 		   struct ocfs2_alloc_context *data_ac)
360 {
361 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
362 	struct posix_acl *acl = NULL;
363 	int ret = 0, ret2;
364 	umode_t mode;
365 
366 	if (!S_ISLNK(inode->i_mode)) {
367 		if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
368 			down_read(&OCFS2_I(dir)->ip_xattr_sem);
369 			acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
370 						   dir_bh);
371 			up_read(&OCFS2_I(dir)->ip_xattr_sem);
372 			if (IS_ERR(acl))
373 				return PTR_ERR(acl);
374 		}
375 		if (!acl) {
376 			mode = inode->i_mode & ~current_umask();
377 			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
378 			if (ret) {
379 				mlog_errno(ret);
380 				goto cleanup;
381 			}
382 		}
383 	}
384 	if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
385 		if (S_ISDIR(inode->i_mode)) {
386 			ret = ocfs2_set_acl(handle, inode, di_bh,
387 					    ACL_TYPE_DEFAULT, acl,
388 					    meta_ac, data_ac);
389 			if (ret)
390 				goto cleanup;
391 		}
392 		mode = inode->i_mode;
393 		ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
394 		if (ret < 0)
395 			return ret;
396 
397 		ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
398 		if (ret2) {
399 			mlog_errno(ret2);
400 			ret = ret2;
401 			goto cleanup;
402 		}
403 		if (ret > 0) {
404 			ret = ocfs2_set_acl(handle, inode,
405 					    di_bh, ACL_TYPE_ACCESS,
406 					    acl, meta_ac, data_ac);
407 		}
408 	}
409 cleanup:
410 	posix_acl_release(acl);
411 	return ret;
412 }
413