xref: /openbmc/linux/fs/ocfs2/acl.c (revision 5f66f73b)
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  */
35 static 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  */
79 static 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 
114 static 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  */
160 static 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 
204 out_commit:
205 	if (commit_handle)
206 		ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
207 out_brelse:
208 	brelse(di_bh);
209 out:
210 	return ret;
211 }
212 
213 /*
214  * Set the access or default ACL of an inode.
215  */
216 static 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 
265 int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
266 		      struct posix_acl *acl, int type)
267 {
268 	struct buffer_head *bh = NULL;
269 	int status, had_lock;
270 	struct ocfs2_lock_holder oh;
271 
272 	had_lock = ocfs2_inode_lock_tracker(inode, &bh, 1, &oh);
273 	if (had_lock < 0)
274 		return had_lock;
275 	if (type == ACL_TYPE_ACCESS && acl) {
276 		umode_t mode;
277 
278 		status = posix_acl_update_mode(&init_user_ns, inode, &mode,
279 					       &acl);
280 		if (status)
281 			goto unlock;
282 
283 		status = ocfs2_acl_set_mode(inode, bh, NULL, mode);
284 		if (status)
285 			goto unlock;
286 	}
287 	status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
288 unlock:
289 	ocfs2_inode_unlock_tracker(inode, 1, &oh, had_lock);
290 	brelse(bh);
291 	return status;
292 }
293 
294 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
295 {
296 	struct ocfs2_super *osb;
297 	struct buffer_head *di_bh = NULL;
298 	struct posix_acl *acl;
299 	int had_lock;
300 	struct ocfs2_lock_holder oh;
301 
302 	osb = OCFS2_SB(inode->i_sb);
303 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
304 		return NULL;
305 
306 	had_lock = ocfs2_inode_lock_tracker(inode, &di_bh, 0, &oh);
307 	if (had_lock < 0)
308 		return ERR_PTR(had_lock);
309 
310 	down_read(&OCFS2_I(inode)->ip_xattr_sem);
311 	acl = ocfs2_get_acl_nolock(inode, type, di_bh);
312 	up_read(&OCFS2_I(inode)->ip_xattr_sem);
313 
314 	ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
315 	brelse(di_bh);
316 	return acl;
317 }
318 
319 int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
320 {
321 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
322 	struct posix_acl *acl;
323 	int ret;
324 
325 	if (S_ISLNK(inode->i_mode))
326 		return -EOPNOTSUPP;
327 
328 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
329 		return 0;
330 
331 	down_read(&OCFS2_I(inode)->ip_xattr_sem);
332 	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
333 	up_read(&OCFS2_I(inode)->ip_xattr_sem);
334 	if (IS_ERR_OR_NULL(acl))
335 		return PTR_ERR_OR_ZERO(acl);
336 	ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
337 	if (ret)
338 		return ret;
339 	ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
340 			    acl, NULL, NULL);
341 	posix_acl_release(acl);
342 	return ret;
343 }
344 
345 /*
346  * Initialize the ACLs of a new inode. If parent directory has default ACL,
347  * then clone to new inode. Called from ocfs2_mknod.
348  */
349 int ocfs2_init_acl(handle_t *handle,
350 		   struct inode *inode,
351 		   struct inode *dir,
352 		   struct buffer_head *di_bh,
353 		   struct buffer_head *dir_bh,
354 		   struct ocfs2_alloc_context *meta_ac,
355 		   struct ocfs2_alloc_context *data_ac)
356 {
357 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
358 	struct posix_acl *acl = NULL;
359 	int ret = 0, ret2;
360 	umode_t mode;
361 
362 	if (!S_ISLNK(inode->i_mode)) {
363 		if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
364 			down_read(&OCFS2_I(dir)->ip_xattr_sem);
365 			acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
366 						   dir_bh);
367 			up_read(&OCFS2_I(dir)->ip_xattr_sem);
368 			if (IS_ERR(acl))
369 				return PTR_ERR(acl);
370 		}
371 		if (!acl) {
372 			mode = inode->i_mode & ~current_umask();
373 			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
374 			if (ret) {
375 				mlog_errno(ret);
376 				goto cleanup;
377 			}
378 		}
379 	}
380 	if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
381 		if (S_ISDIR(inode->i_mode)) {
382 			ret = ocfs2_set_acl(handle, inode, di_bh,
383 					    ACL_TYPE_DEFAULT, acl,
384 					    meta_ac, data_ac);
385 			if (ret)
386 				goto cleanup;
387 		}
388 		mode = inode->i_mode;
389 		ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
390 		if (ret < 0)
391 			return ret;
392 
393 		ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
394 		if (ret2) {
395 			mlog_errno(ret2);
396 			ret = ret2;
397 			goto cleanup;
398 		}
399 		if (ret > 0) {
400 			ret = ocfs2_set_acl(handle, inode,
401 					    di_bh, ACL_TYPE_ACCESS,
402 					    acl, meta_ac, data_ac);
403 		}
404 	}
405 cleanup:
406 	posix_acl_release(acl);
407 	return ret;
408 }
409