xref: /linux/fs/ocfs2/acl.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
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,
114 					      int type,
115 					      struct buffer_head *di_bh)
116 {
117 	int name_index;
118 	char *value = NULL;
119 	struct posix_acl *acl;
120 	int retval;
121 
122 	switch (type) {
123 	case ACL_TYPE_ACCESS:
124 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
125 		break;
126 	case ACL_TYPE_DEFAULT:
127 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
128 		break;
129 	default:
130 		return ERR_PTR(-EINVAL);
131 	}
132 
133 	retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
134 	if (retval > 0) {
135 		value = kmalloc(retval, GFP_NOFS);
136 		if (!value)
137 			return ERR_PTR(-ENOMEM);
138 		retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
139 						"", value, retval);
140 	}
141 
142 	if (retval > 0)
143 		acl = ocfs2_acl_from_xattr(value, retval);
144 	else if (retval == -ENODATA || retval == 0)
145 		acl = NULL;
146 	else
147 		acl = ERR_PTR(retval);
148 
149 	kfree(value);
150 
151 	return acl;
152 }
153 
154 /*
155  * Helper function to set i_mode in memory and disk. Some call paths
156  * will not have di_bh or a journal handle to pass, in which case it
157  * will create it's own.
158  */
159 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
160 			      handle_t *handle, umode_t new_mode)
161 {
162 	int ret, commit_handle = 0;
163 	struct ocfs2_dinode *di;
164 
165 	if (di_bh == NULL) {
166 		ret = ocfs2_read_inode_block(inode, &di_bh);
167 		if (ret) {
168 			mlog_errno(ret);
169 			goto out;
170 		}
171 	} else
172 		get_bh(di_bh);
173 
174 	if (handle == NULL) {
175 		handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
176 					   OCFS2_INODE_UPDATE_CREDITS);
177 		if (IS_ERR(handle)) {
178 			ret = PTR_ERR(handle);
179 			mlog_errno(ret);
180 			goto out_brelse;
181 		}
182 
183 		commit_handle = 1;
184 	}
185 
186 	di = (struct ocfs2_dinode *)di_bh->b_data;
187 	ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
188 				      OCFS2_JOURNAL_ACCESS_WRITE);
189 	if (ret) {
190 		mlog_errno(ret);
191 		goto out_commit;
192 	}
193 
194 	inode->i_mode = new_mode;
195 	inode_set_ctime_current(inode);
196 	di->i_mode = cpu_to_le16(inode->i_mode);
197 	di->i_ctime = cpu_to_le64(inode_get_ctime_sec(inode));
198 	di->i_ctime_nsec = cpu_to_le32(inode_get_ctime_nsec(inode));
199 	ocfs2_update_inode_fsync_trans(handle, inode, 0);
200 
201 	ocfs2_journal_dirty(handle, di_bh);
202 
203 out_commit:
204 	if (commit_handle)
205 		ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
206 out_brelse:
207 	brelse(di_bh);
208 out:
209 	return ret;
210 }
211 
212 /*
213  * Set the access or default ACL of an inode.
214  */
215 static int ocfs2_set_acl(handle_t *handle,
216 			 struct inode *inode,
217 			 struct buffer_head *di_bh,
218 			 int type,
219 			 struct posix_acl *acl,
220 			 struct ocfs2_alloc_context *meta_ac,
221 			 struct ocfs2_alloc_context *data_ac)
222 {
223 	int name_index;
224 	void *value = NULL;
225 	size_t size = 0;
226 	int ret;
227 
228 	if (S_ISLNK(inode->i_mode))
229 		return -EOPNOTSUPP;
230 
231 	switch (type) {
232 	case ACL_TYPE_ACCESS:
233 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
234 		break;
235 	case ACL_TYPE_DEFAULT:
236 		name_index = OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT;
237 		if (!S_ISDIR(inode->i_mode))
238 			return acl ? -EACCES : 0;
239 		break;
240 	default:
241 		return -EINVAL;
242 	}
243 
244 	if (acl) {
245 		value = ocfs2_acl_to_xattr(acl, &size);
246 		if (IS_ERR(value))
247 			return (int)PTR_ERR(value);
248 	}
249 
250 	if (handle)
251 		ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
252 					     "", value, size, 0,
253 					     meta_ac, data_ac);
254 	else
255 		ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
256 
257 	kfree(value);
258 	if (!ret)
259 		set_cached_acl(inode, type, acl);
260 
261 	return ret;
262 }
263 
264 int ocfs2_iop_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
265 		      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 	struct inode *inode = d_inode(dentry);
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(&nop_mnt_idmap, 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, bool rcu)
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 	if (rcu)
303 		return ERR_PTR(-ECHILD);
304 
305 	osb = OCFS2_SB(inode->i_sb);
306 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
307 		return NULL;
308 
309 	had_lock = ocfs2_inode_lock_tracker(inode, &di_bh, 0, &oh);
310 	if (had_lock < 0)
311 		return ERR_PTR(had_lock);
312 
313 	down_read(&OCFS2_I(inode)->ip_xattr_sem);
314 	acl = ocfs2_get_acl_nolock(inode, type, di_bh);
315 	up_read(&OCFS2_I(inode)->ip_xattr_sem);
316 
317 	ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
318 	brelse(di_bh);
319 	return acl;
320 }
321 
322 int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
323 {
324 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
325 	struct posix_acl *acl;
326 	int ret;
327 
328 	if (S_ISLNK(inode->i_mode))
329 		return -EOPNOTSUPP;
330 
331 	if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
332 		return 0;
333 
334 	down_read(&OCFS2_I(inode)->ip_xattr_sem);
335 	acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
336 	up_read(&OCFS2_I(inode)->ip_xattr_sem);
337 	if (IS_ERR_OR_NULL(acl))
338 		return PTR_ERR_OR_ZERO(acl);
339 	ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
340 	if (ret)
341 		return ret;
342 	ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
343 			    acl, NULL, NULL);
344 	posix_acl_release(acl);
345 	return ret;
346 }
347 
348 /*
349  * Initialize the ACLs of a new inode. If parent directory has default ACL,
350  * then clone to new inode. Called from ocfs2_mknod.
351  */
352 int ocfs2_init_acl(handle_t *handle,
353 		   struct inode *inode,
354 		   struct inode *dir,
355 		   struct buffer_head *di_bh,
356 		   struct buffer_head *dir_bh,
357 		   struct ocfs2_alloc_context *meta_ac,
358 		   struct ocfs2_alloc_context *data_ac)
359 {
360 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
361 	struct posix_acl *acl = NULL;
362 	int ret = 0, ret2;
363 	umode_t mode;
364 
365 	if (!S_ISLNK(inode->i_mode)) {
366 		if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
367 			down_read(&OCFS2_I(dir)->ip_xattr_sem);
368 			acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
369 						   dir_bh);
370 			up_read(&OCFS2_I(dir)->ip_xattr_sem);
371 			if (IS_ERR(acl))
372 				return PTR_ERR(acl);
373 		}
374 		if (!acl) {
375 			mode = inode->i_mode & ~current_umask();
376 			ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
377 			if (ret) {
378 				mlog_errno(ret);
379 				goto cleanup;
380 			}
381 		}
382 	}
383 	if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
384 		if (S_ISDIR(inode->i_mode)) {
385 			ret = ocfs2_set_acl(handle, inode, di_bh,
386 					    ACL_TYPE_DEFAULT, acl,
387 					    meta_ac, data_ac);
388 			if (ret)
389 				goto cleanup;
390 		}
391 		mode = inode->i_mode;
392 		ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
393 		if (ret < 0)
394 			return ret;
395 
396 		ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
397 		if (ret2) {
398 			mlog_errno(ret2);
399 			ret = ret2;
400 			goto cleanup;
401 		}
402 		if (ret > 0) {
403 			ret = ocfs2_set_acl(handle, inode,
404 					    di_bh, ACL_TYPE_ACCESS,
405 					    acl, meta_ac, data_ac);
406 		}
407 	}
408 cleanup:
409 	posix_acl_release(acl);
410 	return ret;
411 }
412