xref: /linux/fs/ocfs2/acl.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * acl.c
4  *
5  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
6  *
7  * CREDITS:
8  * Lots of code in this file is copy from linux/fs/ext3/acl.c.
9  * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
10  */
11 
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/string.h>
16 #include <linux/fs_struct.h>
17 
18 #include <cluster/masklog.h>
19 
20 #include "ocfs2.h"
21 #include "alloc.h"
22 #include "dlmglue.h"
23 #include "file.h"
24 #include "inode.h"
25 #include "journal.h"
26 #include "ocfs2_fs.h"
27 
28 #include "xattr.h"
29 #include "acl.h"
30 
31 /*
32  * Convert from xattr value to acl struct.
33  */
34 static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
35 {
36 	int n, count;
37 	struct posix_acl *acl;
38 
39 	if (!value)
40 		return NULL;
41 	if (size < sizeof(struct posix_acl_entry))
42 		return ERR_PTR(-EINVAL);
43 
44 	count = size / sizeof(struct posix_acl_entry);
45 
46 	acl = posix_acl_alloc(count, GFP_NOFS);
47 	if (!acl)
48 		return ERR_PTR(-ENOMEM);
49 	for (n = 0; n < count; n++) {
50 		struct ocfs2_acl_entry *entry =
51 			(struct ocfs2_acl_entry *)value;
52 
53 		acl->a_entries[n].e_tag  = le16_to_cpu(entry->e_tag);
54 		acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
55 		switch(acl->a_entries[n].e_tag) {
56 		case ACL_USER:
57 			acl->a_entries[n].e_uid =
58 				make_kuid(&init_user_ns,
59 					  le32_to_cpu(entry->e_id));
60 			break;
61 		case ACL_GROUP:
62 			acl->a_entries[n].e_gid =
63 				make_kgid(&init_user_ns,
64 					  le32_to_cpu(entry->e_id));
65 			break;
66 		default:
67 			break;
68 		}
69 		value += sizeof(struct posix_acl_entry);
70 
71 	}
72 	return acl;
73 }
74 
75 /*
76  * Convert acl struct to xattr value.
77  */
78 static 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 		switch(acl->a_entries[n].e_tag) {
95 		case ACL_USER:
96 			entry->e_id = cpu_to_le32(
97 				from_kuid(&init_user_ns,
98 					  acl->a_entries[n].e_uid));
99 			break;
100 		case ACL_GROUP:
101 			entry->e_id = cpu_to_le32(
102 				from_kgid(&init_user_ns,
103 					  acl->a_entries[n].e_gid));
104 			break;
105 		default:
106 			entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
107 			break;
108 		}
109 	}
110 	return ocfs2_acl;
111 }
112 
113 static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode, int type,
114 					      struct buffer_head *di_bh)
115 {
116 	int name_index;
117 	char *value = NULL;
118 	struct posix_acl *acl;
119 	int retval;
120 
121 	switch (type) {
122 	case ACL_TYPE_ACCESS:
123 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
124 		break;
125 	case ACL_TYPE_DEFAULT:
126 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
127 		break;
128 	default:
129 		return ERR_PTR(-EINVAL);
130 	}
131 
132 	retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
133 	if (retval > 0) {
134 		value = kmalloc(retval, GFP_NOFS);
135 		if (!value)
136 			return ERR_PTR(-ENOMEM);
137 		retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
138 						"", value, retval);
139 	}
140 
141 	if (retval > 0)
142 		acl = ocfs2_acl_from_xattr(value, retval);
143 	else if (retval == -ENODATA || retval == 0)
144 		acl = NULL;
145 	else
146 		acl = ERR_PTR(retval);
147 
148 	kfree(value);
149 
150 	return acl;
151 }
152 
153 /*
154  * Helper function to set i_mode in memory and disk. Some call paths
155  * will not have di_bh or a journal handle to pass, in which case it
156  * will create it's own.
157  */
158 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
159 			      handle_t *handle, umode_t new_mode)
160 {
161 	int ret, commit_handle = 0;
162 	struct ocfs2_dinode *di;
163 
164 	if (di_bh == NULL) {
165 		ret = ocfs2_read_inode_block(inode, &di_bh);
166 		if (ret) {
167 			mlog_errno(ret);
168 			goto out;
169 		}
170 	} else
171 		get_bh(di_bh);
172 
173 	if (handle == NULL) {
174 		handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
175 					   OCFS2_INODE_UPDATE_CREDITS);
176 		if (IS_ERR(handle)) {
177 			ret = PTR_ERR(handle);
178 			mlog_errno(ret);
179 			goto out_brelse;
180 		}
181 
182 		commit_handle = 1;
183 	}
184 
185 	di = (struct ocfs2_dinode *)di_bh->b_data;
186 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
187 				      OCFS2_JOURNAL_ACCESS_WRITE);
188 	if (ret) {
189 		mlog_errno(ret);
190 		goto out_commit;
191 	}
192 
193 	inode->i_mode = new_mode;
194 	inode_set_ctime_current(inode);
195 	di->i_mode = cpu_to_le16(inode->i_mode);
196 	di->i_ctime = cpu_to_le64(inode_get_ctime_sec(inode));
197 	di->i_ctime_nsec = cpu_to_le32(inode_get_ctime_nsec(inode));
198 	ocfs2_update_inode_fsync_trans(handle, inode, 0);
199 
200 	ocfs2_journal_dirty(handle, di_bh);
201 
202 out_commit:
203 	if (commit_handle)
204 		ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
205 out_brelse:
206 	brelse(di_bh);
207 out:
208 	return ret;
209 }
210 
211 /*
212  * Set the access or default ACL of an inode.
213  */
214 static int ocfs2_set_acl(handle_t *handle,
215 			 struct inode *inode,
216 			 struct buffer_head *di_bh,
217 			 int type,
218 			 struct posix_acl *acl,
219 			 struct ocfs2_alloc_context *meta_ac,
220 			 struct ocfs2_alloc_context *data_ac)
221 {
222 	int name_index;
223 	void *value = NULL;
224 	size_t size = 0;
225 	int ret;
226 
227 	if (S_ISLNK(inode->i_mode))
228 		return -EOPNOTSUPP;
229 
230 	switch (type) {
231 	case ACL_TYPE_ACCESS:
232 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
233 		break;
234 	case ACL_TYPE_DEFAULT:
235 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
236 		if (!S_ISDIR(inode->i_mode))
237 			return acl ? -EACCES : 0;
238 		break;
239 	default:
240 		return -EINVAL;
241 	}
242 
243 	if (acl) {
244 		value = ocfs2_acl_to_xattr(acl, &size);
245 		if (IS_ERR(value))
246 			return (int)PTR_ERR(value);
247 	}
248 
249 	if (handle)
250 		ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
251 					     "", value, size, 0,
252 					     meta_ac, data_ac);
253 	else
254 		ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
255 
256 	kfree(value);
257 	if (!ret)
258 		set_cached_acl(inode, type, acl);
259 
260 	return ret;
261 }
262 
263 int ocfs2_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
264 		      struct posix_acl *acl, int type)
265 {
266 	struct buffer_head *bh = NULL;
267 	int status, had_lock;
268 	struct ocfs2_lock_holder oh;
269 	struct inode *inode = d_inode(dentry);
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(&nop_mnt_idmap, inode, &mode,
278 					       &acl);
279 		if (status)
280 			goto unlock;
281 
282 		status = ocfs2_acl_set_mode(inode, bh, NULL, mode);
283 		if (status)
284 			goto unlock;
285 	}
286 	status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
287 unlock:
288 	ocfs2_inode_unlock_tracker(inode, 1, &oh, had_lock);
289 	brelse(bh);
290 	return status;
291 }
292 
293 struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type, bool rcu)
294 {
295 	struct ocfs2_super *osb;
296 	struct buffer_head *di_bh = NULL;
297 	struct posix_acl *acl;
298 	int had_lock;
299 	struct ocfs2_lock_holder oh;
300 
301 	if (rcu)
302 		return ERR_PTR(-ECHILD);
303 
304 	osb = OCFS2_SB(inode->i_sb);
305 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
306 		return NULL;
307 
308 	had_lock = ocfs2_inode_lock_tracker(inode, &di_bh, 0, &oh);
309 	if (had_lock < 0)
310 		return ERR_PTR(had_lock);
311 
312 	down_read(&OCFS2_I(inode)->ip_xattr_sem);
313 	acl = ocfs2_get_acl_nolock(inode, type, di_bh);
314 	up_read(&OCFS2_I(inode)->ip_xattr_sem);
315 
316 	ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
317 	brelse(di_bh);
318 	return acl;
319 }
320 
321 int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
322 {
323 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
324 	struct posix_acl *acl;
325 	int ret;
326 
327 	if (S_ISLNK(inode->i_mode))
328 		return -EOPNOTSUPP;
329 
330 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
331 		return 0;
332 
333 	down_read(&OCFS2_I(inode)->ip_xattr_sem);
334 	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
335 	up_read(&OCFS2_I(inode)->ip_xattr_sem);
336 	if (IS_ERR_OR_NULL(acl))
337 		return PTR_ERR_OR_ZERO(acl);
338 	ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
339 	if (ret)
340 		return ret;
341 	ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
342 			    acl, NULL, NULL);
343 	posix_acl_release(acl);
344 	return ret;
345 }
346 
347 /*
348  * Initialize the ACLs of a new inode. If parent directory has default ACL,
349  * then clone to new inode. Called from ocfs2_mknod.
350  */
351 void ocfs2_acl_init_release(struct ocfs2_acl_state *state)
352 {
353 	posix_acl_release(state->default_acl);
354 	posix_acl_release(state->acl);
355 	state->default_acl = NULL;
356 	state->acl = NULL;
357 }
358 
359 int ocfs2_acl_init_prepare(struct inode *inode, struct inode *dir,
360 			   struct buffer_head *dir_bh,
361 			   struct ocfs2_acl_state *state)
362 {
363 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
364 	int ret = 0;
365 
366 	state->default_acl = NULL;
367 	state->acl = NULL;
368 	state->mode = inode->i_mode;
369 
370 	if (S_ISLNK(inode->i_mode))
371 		return 0;
372 
373 	if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
374 		down_read(&OCFS2_I(dir)->ip_xattr_sem);
375 		state->default_acl =
376 			ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT, dir_bh);
377 		up_read(&OCFS2_I(dir)->ip_xattr_sem);
378 		if (IS_ERR(state->default_acl)) {
379 			ret = PTR_ERR(state->default_acl);
380 			state->default_acl = NULL;
381 			return ret;
382 		}
383 		if (state->default_acl) {
384 			state->acl = posix_acl_dup(state->default_acl);
385 			if (!state->acl) {
386 				ret = -ENOMEM;
387 				goto cleanup;
388 			}
389 			ret = __posix_acl_create(&state->acl, GFP_NOFS,
390 						 &state->mode);
391 			if (ret < 0)
392 				goto cleanup;
393 			if (ret == 0) {
394 				posix_acl_release(state->acl);
395 				state->acl = NULL;
396 			}
397 			if (!S_ISDIR(inode->i_mode)) {
398 				posix_acl_release(state->default_acl);
399 				state->default_acl = NULL;
400 			}
401 		} else {
402 			state->mode &= ~current_umask();
403 		}
404 	} else {
405 		state->mode &= ~current_umask();
406 	}
407 
408 	return 0;
409 cleanup:
410 	ocfs2_acl_init_release(state);
411 	return ret;
412 }
413 
414 int ocfs2_init_acl(handle_t *handle, struct inode *inode,
415 		   struct buffer_head *di_bh,
416 		   struct ocfs2_alloc_context *meta_ac,
417 		   struct ocfs2_alloc_context *data_ac,
418 		   struct ocfs2_acl_state *state)
419 {
420 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
421 	int ret = 0;
422 
423 	if (S_ISLNK(inode->i_mode))
424 		return 0;
425 
426 	if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
427 		if (S_ISDIR(inode->i_mode) && state->default_acl) {
428 			ret = ocfs2_set_acl(handle, inode, di_bh,
429 					    ACL_TYPE_DEFAULT,
430 					    state->default_acl, meta_ac,
431 					    data_ac);
432 			if (ret)
433 				return ret;
434 		}
435 	}
436 
437 	ret = ocfs2_acl_set_mode(inode, di_bh, handle, state->mode);
438 	if (ret) {
439 		mlog_errno(ret);
440 		return ret;
441 	}
442 
443 	if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
444 		if (state->acl) {
445 			ret = ocfs2_set_acl(handle, inode, di_bh,
446 					    ACL_TYPE_ACCESS, state->acl,
447 					    meta_ac, data_ac);
448 		}
449 	}
450 
451 	return ret;
452 }
453