xref: /openbmc/linux/fs/ntfs3/namei.c (revision 62a9bbf2) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *
4  * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
5  *
6  */
7 
8 #include <linux/fs.h>
9 #include <linux/nls.h>
10 #include <linux/ctype.h>
11 #include <linux/posix_acl.h>
12 
13 #include "debug.h"
14 #include "ntfs.h"
15 #include "ntfs_fs.h"
16 
17 /*
18  * fill_name_de - Format NTFS_DE in @buf.
19  */
20 int fill_name_de(struct ntfs_sb_info *sbi, void *buf, const struct qstr *name,
21 		 const struct cpu_str *uni)
22 {
23 	int err;
24 	struct NTFS_DE *e = buf;
25 	u16 data_size;
26 	struct ATTR_FILE_NAME *fname = (struct ATTR_FILE_NAME *)(e + 1);
27 
28 #ifndef CONFIG_NTFS3_64BIT_CLUSTER
29 	e->ref.high = fname->home.high = 0;
30 #endif
31 	if (uni) {
32 #ifdef __BIG_ENDIAN
33 		int ulen = uni->len;
34 		__le16 *uname = fname->name;
35 		const u16 *name_cpu = uni->name;
36 
37 		while (ulen--)
38 			*uname++ = cpu_to_le16(*name_cpu++);
39 #else
40 		memcpy(fname->name, uni->name, uni->len * sizeof(u16));
41 #endif
42 		fname->name_len = uni->len;
43 
44 	} else {
45 		/* Convert input string to unicode. */
46 		err = ntfs_nls_to_utf16(sbi, name->name, name->len,
47 					(struct cpu_str *)&fname->name_len,
48 					NTFS_NAME_LEN, UTF16_LITTLE_ENDIAN);
49 		if (err < 0)
50 			return err;
51 	}
52 
53 	fname->type = FILE_NAME_POSIX;
54 	data_size = fname_full_size(fname);
55 
56 	e->size = cpu_to_le16(ALIGN(data_size, 8) + sizeof(struct NTFS_DE));
57 	e->key_size = cpu_to_le16(data_size);
58 	e->flags = 0;
59 	e->res = 0;
60 
61 	return 0;
62 }
63 
64 /*
65  * ntfs_lookup - inode_operations::lookup
66  */
67 static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
68 				  u32 flags)
69 {
70 	struct ntfs_inode *ni = ntfs_i(dir);
71 	struct cpu_str *uni = __getname();
72 	struct inode *inode;
73 	int err;
74 
75 	if (!uni)
76 		inode = ERR_PTR(-ENOMEM);
77 	else {
78 		err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
79 					dentry->d_name.len, uni, NTFS_NAME_LEN,
80 					UTF16_HOST_ENDIAN);
81 		if (err < 0)
82 			inode = ERR_PTR(err);
83 		else {
84 			ni_lock(ni);
85 			inode = dir_search_u(dir, uni, NULL);
86 			ni_unlock(ni);
87 		}
88 		__putname(uni);
89 	}
90 
91 	return d_splice_alias(inode, dentry);
92 }
93 
94 /*
95  * ntfs_create - inode_operations::create
96  */
97 static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
98 		       struct dentry *dentry, umode_t mode, bool excl)
99 {
100 	struct inode *inode;
101 
102 	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
103 				  0, NULL, 0, NULL);
104 
105 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
106 }
107 
108 /*
109  * ntfs_mknod
110  *
111  * inode_operations::mknod
112  */
113 static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
114 		      struct dentry *dentry, umode_t mode, dev_t rdev)
115 {
116 	struct inode *inode;
117 
118 	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
119 				  NULL, 0, NULL);
120 
121 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
122 }
123 
124 /*
125  * ntfs_link - inode_operations::link
126  */
127 static int ntfs_link(struct dentry *ode, struct inode *dir, struct dentry *de)
128 {
129 	int err;
130 	struct inode *inode = d_inode(ode);
131 	struct ntfs_inode *ni = ntfs_i(inode);
132 
133 	if (S_ISDIR(inode->i_mode))
134 		return -EPERM;
135 
136 	if (inode->i_nlink >= NTFS_LINK_MAX)
137 		return -EMLINK;
138 
139 	ni_lock_dir(ntfs_i(dir));
140 	if (inode != dir)
141 		ni_lock(ni);
142 
143 	inc_nlink(inode);
144 	ihold(inode);
145 
146 	err = ntfs_link_inode(inode, de);
147 
148 	if (!err) {
149 		dir->i_ctime = dir->i_mtime = inode->i_ctime =
150 			current_time(dir);
151 		mark_inode_dirty(inode);
152 		mark_inode_dirty(dir);
153 		d_instantiate(de, inode);
154 	} else {
155 		drop_nlink(inode);
156 		iput(inode);
157 	}
158 
159 	if (inode != dir)
160 		ni_unlock(ni);
161 	ni_unlock(ntfs_i(dir));
162 
163 	return err;
164 }
165 
166 /*
167  * ntfs_unlink - inode_operations::unlink
168  */
169 static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
170 {
171 	struct ntfs_inode *ni = ntfs_i(dir);
172 	int err;
173 
174 	ni_lock_dir(ni);
175 
176 	err = ntfs_unlink_inode(dir, dentry);
177 
178 	ni_unlock(ni);
179 
180 	return err;
181 }
182 
183 /*
184  * ntfs_symlink - inode_operations::symlink
185  */
186 static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
187 			struct dentry *dentry, const char *symname)
188 {
189 	u32 size = strlen(symname);
190 	struct inode *inode;
191 
192 	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
193 				  0, symname, size, NULL);
194 
195 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
196 }
197 
198 /*
199  * ntfs_mkdir- inode_operations::mkdir
200  */
201 static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
202 		      struct dentry *dentry, umode_t mode)
203 {
204 	struct inode *inode;
205 
206 	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
207 				  0, NULL, 0, NULL);
208 
209 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
210 }
211 
212 /*
213  * ntfs_rmdir - inode_operations::rmdir
214  */
215 static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
216 {
217 	struct ntfs_inode *ni = ntfs_i(dir);
218 	int err;
219 
220 	ni_lock_dir(ni);
221 
222 	err = ntfs_unlink_inode(dir, dentry);
223 
224 	ni_unlock(ni);
225 
226 	return err;
227 }
228 
229 /*
230  * ntfs_rename - inode_operations::rename
231  */
232 static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
233 		       struct dentry *dentry, struct inode *new_dir,
234 		       struct dentry *new_dentry, u32 flags)
235 {
236 	int err;
237 	struct super_block *sb = dir->i_sb;
238 	struct ntfs_sb_info *sbi = sb->s_fs_info;
239 	struct ntfs_inode *dir_ni = ntfs_i(dir);
240 	struct ntfs_inode *new_dir_ni = ntfs_i(new_dir);
241 	struct inode *inode = d_inode(dentry);
242 	struct ntfs_inode *ni = ntfs_i(inode);
243 	struct inode *new_inode = d_inode(new_dentry);
244 	struct NTFS_DE *de, *new_de;
245 	bool is_same, is_bad;
246 	/*
247 	 * de		- memory of PATH_MAX bytes:
248 	 * [0-1024)	- original name (dentry->d_name)
249 	 * [1024-2048)	- paired to original name, usually DOS variant of dentry->d_name
250 	 * [2048-3072)	- new name (new_dentry->d_name)
251 	 */
252 	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + SIZEOF_RESIDENT < 1024);
253 	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + sizeof(struct NTFS_DE) <
254 		      1024);
255 	static_assert(PATH_MAX >= 4 * 1024);
256 
257 	if (flags & ~RENAME_NOREPLACE)
258 		return -EINVAL;
259 
260 	is_same = dentry->d_name.len == new_dentry->d_name.len &&
261 		  !memcmp(dentry->d_name.name, new_dentry->d_name.name,
262 			  dentry->d_name.len);
263 
264 	if (is_same && dir == new_dir) {
265 		/* Nothing to do. */
266 		return 0;
267 	}
268 
269 	if (ntfs_is_meta_file(sbi, inode->i_ino)) {
270 		/* Should we print an error? */
271 		return -EINVAL;
272 	}
273 
274 	if (new_inode) {
275 		/* Target name exists. Unlink it. */
276 		dget(new_dentry);
277 		ni_lock_dir(new_dir_ni);
278 		err = ntfs_unlink_inode(new_dir, new_dentry);
279 		ni_unlock(new_dir_ni);
280 		dput(new_dentry);
281 		if (err)
282 			return err;
283 	}
284 
285 	/* Allocate PATH_MAX bytes. */
286 	de = __getname();
287 	if (!de)
288 		return -ENOMEM;
289 
290 	/* Translate dentry->d_name into unicode form. */
291 	err = fill_name_de(sbi, de, &dentry->d_name, NULL);
292 	if (err < 0)
293 		goto out;
294 
295 	if (is_same) {
296 		/* Reuse 'de'. */
297 		new_de = de;
298 	} else {
299 		/* Translate new_dentry->d_name into unicode form. */
300 		new_de = Add2Ptr(de, 2048);
301 		err = fill_name_de(sbi, new_de, &new_dentry->d_name, NULL);
302 		if (err < 0)
303 			goto out;
304 	}
305 
306 	ni_lock_dir(dir_ni);
307 	ni_lock(ni);
308 	if (dir_ni != new_dir_ni)
309 		ni_lock_dir2(new_dir_ni);
310 
311 	is_bad = false;
312 	err = ni_rename(dir_ni, new_dir_ni, ni, de, new_de, &is_bad);
313 	if (is_bad) {
314 		/* Restore after failed rename failed too. */
315 		_ntfs_bad_inode(inode);
316 	} else if (!err) {
317 		inode->i_ctime = dir->i_ctime = dir->i_mtime =
318 			current_time(dir);
319 		mark_inode_dirty(inode);
320 		mark_inode_dirty(dir);
321 		if (dir != new_dir) {
322 			new_dir->i_mtime = new_dir->i_ctime = dir->i_ctime;
323 			mark_inode_dirty(new_dir);
324 		}
325 
326 		if (IS_DIRSYNC(dir))
327 			ntfs_sync_inode(dir);
328 
329 		if (IS_DIRSYNC(new_dir))
330 			ntfs_sync_inode(inode);
331 	}
332 
333 	if (dir_ni != new_dir_ni)
334 		ni_unlock(new_dir_ni);
335 	ni_unlock(ni);
336 	ni_unlock(dir_ni);
337 out:
338 	__putname(de);
339 	return err;
340 }
341 
342 /*
343  * ntfs_atomic_open
344  *
345  * inode_operations::atomic_open
346  */
347 static int ntfs_atomic_open(struct inode *dir, struct dentry *dentry,
348 			    struct file *file, u32 flags, umode_t mode)
349 {
350 	int err;
351 	struct inode *inode;
352 	struct ntfs_fnd *fnd = NULL;
353 	struct ntfs_inode *ni = ntfs_i(dir);
354 	struct dentry *d = NULL;
355 	struct cpu_str *uni = __getname();
356 	bool locked = false;
357 
358 	if (!uni)
359 		return -ENOMEM;
360 
361 	err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
362 				dentry->d_name.len, uni, NTFS_NAME_LEN,
363 				UTF16_HOST_ENDIAN);
364 	if (err < 0)
365 		goto out;
366 
367 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
368 	if (IS_POSIXACL(dir)) {
369 		/*
370 		 * Load in cache current acl to avoid ni_lock(dir):
371 		 * ntfs_create_inode -> ntfs_init_acl -> posix_acl_create ->
372 		 * ntfs_get_acl -> ntfs_get_acl_ex -> ni_lock
373 		 */
374 		struct posix_acl *p = get_inode_acl(dir, ACL_TYPE_DEFAULT);
375 
376 		if (IS_ERR(p)) {
377 			err = PTR_ERR(p);
378 			goto out;
379 		}
380 		posix_acl_release(p);
381 	}
382 #endif
383 
384 	if (d_in_lookup(dentry)) {
385 		ni_lock_dir(ni);
386 		locked = true;
387 		fnd = fnd_get();
388 		if (!fnd) {
389 			err = -ENOMEM;
390 			goto out1;
391 		}
392 
393 		d = d_splice_alias(dir_search_u(dir, uni, fnd), dentry);
394 		if (IS_ERR(d)) {
395 			err = PTR_ERR(d);
396 			d = NULL;
397 			goto out2;
398 		}
399 
400 		if (d)
401 			dentry = d;
402 	}
403 
404 	if (!(flags & O_CREAT) || d_really_is_positive(dentry)) {
405 		err = finish_no_open(file, d);
406 		goto out2;
407 	}
408 
409 	file->f_mode |= FMODE_CREATED;
410 
411 	/*
412 	 * fnd contains tree's path to insert to.
413 	 * If fnd is not NULL then dir is locked.
414 	 */
415 
416 	/*
417 	 * Unfortunately I don't know how to get here correct 'struct nameidata *nd'
418 	 * or 'struct user_namespace *mnt_userns'.
419 	 * See atomic_open in fs/namei.c.
420 	 * This is why xfstest/633 failed.
421 	 * Looks like ntfs_atomic_open must accept 'struct user_namespace *mnt_userns' as argument.
422 	 */
423 
424 	inode = ntfs_create_inode(&init_user_ns, dir, dentry, uni, mode, 0,
425 				  NULL, 0, fnd);
426 	err = IS_ERR(inode) ? PTR_ERR(inode)
427 			    : finish_open(file, dentry, ntfs_file_open);
428 	dput(d);
429 
430 out2:
431 	fnd_put(fnd);
432 out1:
433 	if (locked)
434 		ni_unlock(ni);
435 out:
436 	__putname(uni);
437 	return err;
438 }
439 
440 struct dentry *ntfs3_get_parent(struct dentry *child)
441 {
442 	struct inode *inode = d_inode(child);
443 	struct ntfs_inode *ni = ntfs_i(inode);
444 
445 	struct ATTR_LIST_ENTRY *le = NULL;
446 	struct ATTRIB *attr = NULL;
447 	struct ATTR_FILE_NAME *fname;
448 
449 	while ((attr = ni_find_attr(ni, attr, &le, ATTR_NAME, NULL, 0, NULL,
450 				    NULL))) {
451 		fname = resident_data_ex(attr, SIZEOF_ATTRIBUTE_FILENAME);
452 		if (!fname)
453 			continue;
454 
455 		return d_obtain_alias(
456 			ntfs_iget5(inode->i_sb, &fname->home, NULL));
457 	}
458 
459 	return ERR_PTR(-ENOENT);
460 }
461 
462 /*
463  * dentry_operations::d_hash
464  */
465 static int ntfs_d_hash(const struct dentry *dentry, struct qstr *name)
466 {
467 	struct ntfs_sb_info *sbi;
468 	const char *n = name->name;
469 	unsigned int len = name->len;
470 	unsigned long hash;
471 	struct cpu_str *uni;
472 	unsigned int c;
473 	int err;
474 
475 	/* First try fast implementation. */
476 	hash = init_name_hash(dentry);
477 
478 	for (;;) {
479 		if (!len--) {
480 			name->hash = end_name_hash(hash);
481 			return 0;
482 		}
483 
484 		c = *n++;
485 		if (c >= 0x80)
486 			break;
487 
488 		hash = partial_name_hash(toupper(c), hash);
489 	}
490 
491 	/*
492 	 * Try slow way with current upcase table
493 	 */
494 	uni = __getname();
495 	if (!uni)
496 		return -ENOMEM;
497 
498 	sbi = dentry->d_sb->s_fs_info;
499 
500 	err = ntfs_nls_to_utf16(sbi, name->name, name->len, uni, NTFS_NAME_LEN,
501 				UTF16_HOST_ENDIAN);
502 	if (err < 0)
503 		goto out;
504 
505 	if (!err) {
506 		err = -EINVAL;
507 		goto out;
508 	}
509 
510 	hash = ntfs_names_hash(uni->name, uni->len, sbi->upcase,
511 			       init_name_hash(dentry));
512 	name->hash = end_name_hash(hash);
513 	err = 0;
514 
515 out:
516 	__putname(uni);
517 	return err;
518 }
519 
520 /*
521  * dentry_operations::d_compare
522  */
523 static int ntfs_d_compare(const struct dentry *dentry, unsigned int len1,
524 			  const char *str, const struct qstr *name)
525 {
526 	struct ntfs_sb_info *sbi;
527 	int ret;
528 	const char *n1 = str;
529 	const char *n2 = name->name;
530 	unsigned int len2 = name->len;
531 	unsigned int lm = min(len1, len2);
532 	unsigned char c1, c2;
533 	struct cpu_str *uni1;
534 	struct le_str *uni2;
535 
536 	/* First try fast implementation. */
537 	for (;;) {
538 		if (!lm--)
539 			return len1 != len2;
540 
541 		if ((c1 = *n1++) == (c2 = *n2++))
542 			continue;
543 
544 		if (c1 >= 0x80 || c2 >= 0x80)
545 			break;
546 
547 		if (toupper(c1) != toupper(c2))
548 			return 1;
549 	}
550 
551 	/*
552 	 * Try slow way with current upcase table
553 	 */
554 	sbi = dentry->d_sb->s_fs_info;
555 	uni1 = __getname();
556 	if (!uni1)
557 		return -ENOMEM;
558 
559 	ret = ntfs_nls_to_utf16(sbi, str, len1, uni1, NTFS_NAME_LEN,
560 				UTF16_HOST_ENDIAN);
561 	if (ret < 0)
562 		goto out;
563 
564 	if (!ret) {
565 		ret = -EINVAL;
566 		goto out;
567 	}
568 
569 	uni2 = Add2Ptr(uni1, 2048);
570 
571 	ret = ntfs_nls_to_utf16(sbi, name->name, name->len,
572 				(struct cpu_str *)uni2, NTFS_NAME_LEN,
573 				UTF16_LITTLE_ENDIAN);
574 	if (ret < 0)
575 		goto out;
576 
577 	if (!ret) {
578 		ret = -EINVAL;
579 		goto out;
580 	}
581 
582 	ret = !ntfs_cmp_names_cpu(uni1, uni2, sbi->upcase, false) ? 0 : 1;
583 
584 out:
585 	__putname(uni1);
586 	return ret;
587 }
588 
589 // clang-format off
590 const struct inode_operations ntfs_dir_inode_operations = {
591 	.lookup		= ntfs_lookup,
592 	.create		= ntfs_create,
593 	.link		= ntfs_link,
594 	.unlink		= ntfs_unlink,
595 	.symlink	= ntfs_symlink,
596 	.mkdir		= ntfs_mkdir,
597 	.rmdir		= ntfs_rmdir,
598 	.mknod		= ntfs_mknod,
599 	.rename		= ntfs_rename,
600 	.permission	= ntfs_permission,
601 	.get_inode_acl	= ntfs_get_acl,
602 	.set_acl	= ntfs_set_acl,
603 	.setattr	= ntfs3_setattr,
604 	.getattr	= ntfs_getattr,
605 	.listxattr	= ntfs_listxattr,
606 	.atomic_open	= ntfs_atomic_open,
607 	.fiemap		= ntfs_fiemap,
608 };
609 
610 const struct inode_operations ntfs_special_inode_operations = {
611 	.setattr	= ntfs3_setattr,
612 	.getattr	= ntfs_getattr,
613 	.listxattr	= ntfs_listxattr,
614 	.get_inode_acl	= ntfs_get_acl,
615 	.set_acl	= ntfs_set_acl,
616 };
617 
618 const struct dentry_operations ntfs_dentry_ops = {
619 	.d_hash		= ntfs_d_hash,
620 	.d_compare	= ntfs_d_compare,
621 };
622 
623 // clang-format on
624