xref: /linux/fs/smb/client/link.c (revision db68e4c80d995b67a92460711038b9223166bda7)
1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3  *
4  *   Copyright (C) International Business Machines  Corp., 2002,2008
5  *   Author(s): Steve French (sfrench@us.ibm.com)
6  *
7  */
8 #include <linux/fs.h>
9 #include <linux/stat.h>
10 #include <linux/slab.h>
11 #include <linux/namei.h>
12 #include "cifsfs.h"
13 #include "cifspdu.h"
14 #include "cifsglob.h"
15 #include "cifsproto.h"
16 #include "cifs_debug.h"
17 #include "cifs_fs_sb.h"
18 #include "cifs_unicode.h"
19 #include "smb2proto.h"
20 #include "cifs_ioctl.h"
21 #include "fs_context.h"
22 #include "reparse.h"
23 
24 /*
25  * M-F Symlink Functions - Begin
26  */
27 
28 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
29 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
30 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
31 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
32 #define CIFS_MF_SYMLINK_FILE_SIZE \
33 	(CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
34 
35 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
36 #define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
37 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
38 
39 static int
symlink_hash(unsigned int link_len,const char * link_str,u8 * md5_hash)40 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
41 {
42 	int rc;
43 	struct shash_desc *md5 = NULL;
44 
45 	rc = cifs_alloc_hash("md5", &md5);
46 	if (rc)
47 		return rc;
48 
49 	rc = crypto_shash_digest(md5, link_str, link_len, md5_hash);
50 	if (rc)
51 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
52 	cifs_free_hash(&md5);
53 	return rc;
54 }
55 
56 static int
parse_mf_symlink(const u8 * buf,unsigned int buf_len,unsigned int * _link_len,char ** _link_str)57 parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
58 		 char **_link_str)
59 {
60 	int rc;
61 	unsigned int link_len;
62 	const char *md5_str1;
63 	const char *link_str;
64 	u8 md5_hash[16];
65 	char md5_str2[34];
66 
67 	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
68 		return -EINVAL;
69 
70 	md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
71 	link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
72 
73 	rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
74 	if (rc != 1)
75 		return -EINVAL;
76 
77 	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
78 		return -EINVAL;
79 
80 	rc = symlink_hash(link_len, link_str, md5_hash);
81 	if (rc) {
82 		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
83 		return rc;
84 	}
85 
86 	scnprintf(md5_str2, sizeof(md5_str2),
87 		  CIFS_MF_SYMLINK_MD5_FORMAT,
88 		  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
89 
90 	if (strncmp(md5_str1, md5_str2, 17) != 0)
91 		return -EINVAL;
92 
93 	if (_link_str) {
94 		*_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
95 		if (!*_link_str)
96 			return -ENOMEM;
97 	}
98 
99 	*_link_len = link_len;
100 	return 0;
101 }
102 
103 static int
format_mf_symlink(u8 * buf,unsigned int buf_len,const char * link_str)104 format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
105 {
106 	int rc;
107 	unsigned int link_len;
108 	unsigned int ofs;
109 	u8 md5_hash[16];
110 
111 	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
112 		return -EINVAL;
113 
114 	link_len = strlen(link_str);
115 
116 	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
117 		return -ENAMETOOLONG;
118 
119 	rc = symlink_hash(link_len, link_str, md5_hash);
120 	if (rc) {
121 		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
122 		return rc;
123 	}
124 
125 	scnprintf(buf, buf_len,
126 		  CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
127 		  link_len,
128 		  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
129 
130 	ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
131 	memcpy(buf + ofs, link_str, link_len);
132 
133 	ofs += link_len;
134 	if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
135 		buf[ofs] = '\n';
136 		ofs++;
137 	}
138 
139 	while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
140 		buf[ofs] = ' ';
141 		ofs++;
142 	}
143 
144 	return 0;
145 }
146 
147 bool
couldbe_mf_symlink(const struct cifs_fattr * fattr)148 couldbe_mf_symlink(const struct cifs_fattr *fattr)
149 {
150 	if (!S_ISREG(fattr->cf_mode))
151 		/* it's not a symlink */
152 		return false;
153 
154 	if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
155 		/* it's not a symlink */
156 		return false;
157 
158 	return true;
159 }
160 
161 static int
create_mf_symlink(const unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const char * fromName,const char * toName)162 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
163 		  struct cifs_sb_info *cifs_sb, const char *fromName,
164 		  const char *toName)
165 {
166 	int rc;
167 	u8 *buf;
168 	unsigned int bytes_written = 0;
169 
170 	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
171 	if (!buf)
172 		return -ENOMEM;
173 
174 	rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
175 	if (rc)
176 		goto out;
177 
178 	if (tcon->ses->server->ops->create_mf_symlink)
179 		rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
180 					cifs_sb, fromName, buf, &bytes_written);
181 	else
182 		rc = -EOPNOTSUPP;
183 
184 	if (rc)
185 		goto out;
186 
187 	if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
188 		rc = -EIO;
189 out:
190 	kfree(buf);
191 	return rc;
192 }
193 
194 int
check_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,struct cifs_fattr * fattr,const unsigned char * path)195 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
196 		 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
197 		 const unsigned char *path)
198 {
199 	int rc;
200 	u8 *buf = NULL;
201 	unsigned int link_len = 0;
202 	unsigned int bytes_read = 0;
203 	char *symlink = NULL;
204 
205 	if (!couldbe_mf_symlink(fattr))
206 		/* it's not a symlink */
207 		return 0;
208 
209 	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
210 	if (!buf)
211 		return -ENOMEM;
212 
213 	if (tcon->ses->server->ops->query_mf_symlink)
214 		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
215 					      cifs_sb, path, buf, &bytes_read);
216 	else
217 		rc = -ENOSYS;
218 
219 	if (rc)
220 		goto out;
221 
222 	if (bytes_read == 0) /* not a symlink */
223 		goto out;
224 
225 	rc = parse_mf_symlink(buf, bytes_read, &link_len, &symlink);
226 	if (rc == -EINVAL) {
227 		/* it's not a symlink */
228 		rc = 0;
229 		goto out;
230 	}
231 
232 	if (rc != 0)
233 		goto out;
234 
235 	/* it is a symlink */
236 	fattr->cf_eof = link_len;
237 	fattr->cf_mode &= ~S_IFMT;
238 	fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
239 	fattr->cf_dtype = DT_LNK;
240 	fattr->cf_symlink_target = symlink;
241 out:
242 	kfree(buf);
243 	return rc;
244 }
245 
246 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
247 /*
248  * SMB 1.0 Protocol specific functions
249  */
250 
251 int
cifs_query_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_read)252 cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
253 		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
254 		      char *pbuf, unsigned int *pbytes_read)
255 {
256 	int rc;
257 	int oplock = 0;
258 	struct cifs_fid fid;
259 	struct cifs_open_parms oparms;
260 	struct cifs_io_parms io_parms = {0};
261 	int buf_type = CIFS_NO_BUFFER;
262 	struct cifs_open_info_data query_data;
263 
264 	oparms = (struct cifs_open_parms) {
265 		.tcon = tcon,
266 		.cifs_sb = cifs_sb,
267 		.desired_access = GENERIC_READ,
268 		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
269 		.disposition = FILE_OPEN,
270 		.path = path,
271 		.fid = &fid,
272 	};
273 
274 	rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, &query_data);
275 	if (rc)
276 		return rc;
277 
278 	if (query_data.fi.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
279 		rc = -ENOENT;
280 		/* it's not a symlink */
281 		goto out;
282 	}
283 
284 	io_parms.netfid = fid.netfid;
285 	io_parms.pid = current->tgid;
286 	io_parms.tcon = tcon;
287 	io_parms.offset = 0;
288 	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
289 
290 	rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
291 out:
292 	CIFSSMBClose(xid, tcon, fid.netfid);
293 	return rc;
294 }
295 
296 int
cifs_create_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_written)297 cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
298 		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
299 		       char *pbuf, unsigned int *pbytes_written)
300 {
301 	int rc;
302 	int oplock = 0;
303 	struct cifs_fid fid;
304 	struct cifs_open_parms oparms;
305 	struct cifs_io_parms io_parms = {0};
306 
307 	oparms = (struct cifs_open_parms) {
308 		.tcon = tcon,
309 		.cifs_sb = cifs_sb,
310 		.desired_access = GENERIC_WRITE,
311 		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
312 		.disposition = FILE_CREATE,
313 		.path = path,
314 		.fid = &fid,
315 	};
316 
317 	rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);
318 	if (rc)
319 		return rc;
320 
321 	io_parms.netfid = fid.netfid;
322 	io_parms.pid = current->tgid;
323 	io_parms.tcon = tcon;
324 	io_parms.offset = 0;
325 	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
326 
327 	rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
328 	CIFSSMBClose(xid, tcon, fid.netfid);
329 	return rc;
330 }
331 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
332 
333 /*
334  * SMB 2.1/SMB3 Protocol specific functions
335  */
336 int
smb3_query_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_read)337 smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
338 		      struct cifs_sb_info *cifs_sb, const unsigned char *path,
339 		      char *pbuf, unsigned int *pbytes_read)
340 {
341 	int rc;
342 	struct cifs_fid fid;
343 	struct cifs_open_parms oparms;
344 	struct cifs_io_parms io_parms = {0};
345 	int buf_type = CIFS_NO_BUFFER;
346 	__le16 *utf16_path;
347 	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
348 	struct smb2_file_all_info *pfile_info = NULL;
349 
350 	oparms = (struct cifs_open_parms) {
351 		.tcon = tcon,
352 		.cifs_sb = cifs_sb,
353 		.path = path,
354 		.desired_access = GENERIC_READ,
355 		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
356 		.disposition = FILE_OPEN,
357 		.fid = &fid,
358 	};
359 
360 	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
361 	if (utf16_path == NULL)
362 		return -ENOMEM;
363 
364 	pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
365 			     GFP_KERNEL);
366 
367 	if (pfile_info == NULL) {
368 		kfree(utf16_path);
369 		return  -ENOMEM;
370 	}
371 
372 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
373 		       NULL, NULL);
374 	if (rc)
375 		goto qmf_out_open_fail;
376 
377 	if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
378 		/* it's not a symlink */
379 		rc = -ENOENT; /* Is there a better rc to return? */
380 		goto qmf_out;
381 	}
382 
383 	io_parms.netfid = fid.netfid;
384 	io_parms.pid = current->tgid;
385 	io_parms.tcon = tcon;
386 	io_parms.offset = 0;
387 	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
388 	io_parms.persistent_fid = fid.persistent_fid;
389 	io_parms.volatile_fid = fid.volatile_fid;
390 	rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
391 qmf_out:
392 	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
393 qmf_out_open_fail:
394 	kfree(utf16_path);
395 	kfree(pfile_info);
396 	return rc;
397 }
398 
399 int
smb3_create_mf_symlink(unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char * pbuf,unsigned int * pbytes_written)400 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
401 		       struct cifs_sb_info *cifs_sb, const unsigned char *path,
402 		       char *pbuf, unsigned int *pbytes_written)
403 {
404 	int rc;
405 	struct cifs_fid fid;
406 	struct cifs_open_parms oparms;
407 	struct cifs_io_parms io_parms = {0};
408 	__le16 *utf16_path;
409 	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
410 	struct kvec iov[2];
411 
412 	cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
413 
414 	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
415 	if (!utf16_path)
416 		return -ENOMEM;
417 
418 	oparms = (struct cifs_open_parms) {
419 		.tcon = tcon,
420 		.cifs_sb = cifs_sb,
421 		.path = path,
422 		.desired_access = GENERIC_WRITE,
423 		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR),
424 		.disposition = FILE_CREATE,
425 		.fid = &fid,
426 		.mode = 0644,
427 	};
428 
429 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
430 		       NULL, NULL);
431 	if (rc) {
432 		kfree(utf16_path);
433 		return rc;
434 	}
435 
436 	io_parms.netfid = fid.netfid;
437 	io_parms.pid = current->tgid;
438 	io_parms.tcon = tcon;
439 	io_parms.offset = 0;
440 	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
441 	io_parms.persistent_fid = fid.persistent_fid;
442 	io_parms.volatile_fid = fid.volatile_fid;
443 
444 	/* iov[0] is reserved for smb header */
445 	iov[1].iov_base = pbuf;
446 	iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
447 
448 	rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
449 
450 	/* Make sure we wrote all of the symlink data */
451 	if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
452 		rc = -EIO;
453 
454 	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
455 
456 	kfree(utf16_path);
457 	return rc;
458 }
459 
460 /*
461  * M-F Symlink Functions - End
462  */
463 
464 int
cifs_hardlink(struct dentry * old_file,struct inode * inode,struct dentry * direntry)465 cifs_hardlink(struct dentry *old_file, struct inode *inode,
466 	      struct dentry *direntry)
467 {
468 	int rc = -EACCES;
469 	unsigned int xid;
470 	const char *from_name, *to_name;
471 	void *page1, *page2;
472 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
473 	struct tcon_link *tlink;
474 	struct cifs_tcon *tcon;
475 	struct TCP_Server_Info *server;
476 	struct cifsInodeInfo *cifsInode;
477 
478 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
479 		return -EIO;
480 
481 	tlink = cifs_sb_tlink(cifs_sb);
482 	if (IS_ERR(tlink))
483 		return PTR_ERR(tlink);
484 	tcon = tlink_tcon(tlink);
485 
486 	xid = get_xid();
487 	page1 = alloc_dentry_path();
488 	page2 = alloc_dentry_path();
489 
490 	from_name = build_path_from_dentry(old_file, page1);
491 	if (IS_ERR(from_name)) {
492 		rc = PTR_ERR(from_name);
493 		goto cifs_hl_exit;
494 	}
495 	to_name = build_path_from_dentry(direntry, page2);
496 	if (IS_ERR(to_name)) {
497 		rc = PTR_ERR(to_name);
498 		goto cifs_hl_exit;
499 	}
500 
501 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
502 	if (tcon->unix_ext)
503 		rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
504 					    cifs_sb->local_nls,
505 					    cifs_remap(cifs_sb));
506 	else {
507 #else
508 	{
509 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
510 		server = tcon->ses->server;
511 		if (!server->ops->create_hardlink) {
512 			rc = -ENOSYS;
513 			goto cifs_hl_exit;
514 		}
515 		rc = server->ops->create_hardlink(xid, tcon, old_file,
516 						  from_name, to_name, cifs_sb);
517 		if ((rc == -EIO) || (rc == -EINVAL))
518 			rc = -EOPNOTSUPP;
519 	}
520 
521 	d_drop(direntry);	/* force new lookup from server of target */
522 
523 	/*
524 	 * if source file is cached (oplocked) revalidate will not go to server
525 	 * until the file is closed or oplock broken so update nlinks locally
526 	 */
527 	if (d_really_is_positive(old_file)) {
528 		cifsInode = CIFS_I(d_inode(old_file));
529 		if (rc == 0) {
530 			spin_lock(&d_inode(old_file)->i_lock);
531 			inc_nlink(d_inode(old_file));
532 			spin_unlock(&d_inode(old_file)->i_lock);
533 
534 			/*
535 			 * parent dir timestamps will update from srv within a
536 			 * second, would it really be worth it to set the parent
537 			 * dir cifs inode time to zero to force revalidate
538 			 * (faster) for it too?
539 			 */
540 		}
541 		/*
542 		 * if not oplocked will force revalidate to get info on source
543 		 * file from srv.  Note Samba server prior to 4.2 has bug -
544 		 * not updating src file ctime on hardlinks but Windows servers
545 		 * handle it properly
546 		 */
547 		cifsInode->time = 0;
548 
549 		/*
550 		 * Will update parent dir timestamps from srv within a second.
551 		 * Would it really be worth it to set the parent dir (cifs
552 		 * inode) time field to zero to force revalidate on parent
553 		 * directory faster ie
554 		 *
555 		 * CIFS_I(inode)->time = 0;
556 		 */
557 	}
558 
559 cifs_hl_exit:
560 	free_dentry_path(page1);
561 	free_dentry_path(page2);
562 	free_xid(xid);
563 	cifs_put_tlink(tlink);
564 	return rc;
565 }
566 
567 int
568 cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
569 	     struct dentry *direntry, const char *symname)
570 {
571 	int rc = -EOPNOTSUPP;
572 	unsigned int xid;
573 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
574 	struct tcon_link *tlink;
575 	struct cifs_tcon *pTcon;
576 	const char *full_path;
577 	void *page;
578 	struct inode *newinode = NULL;
579 
580 	if (unlikely(cifs_forced_shutdown(cifs_sb)))
581 		return -EIO;
582 
583 	page = alloc_dentry_path();
584 	if (!page)
585 		return -ENOMEM;
586 
587 	xid = get_xid();
588 
589 	tlink = cifs_sb_tlink(cifs_sb);
590 	if (IS_ERR(tlink)) {
591 		rc = PTR_ERR(tlink);
592 		/* BB could be clearer if skipped put_tlink on error here, but harmless */
593 		goto symlink_exit;
594 	}
595 	pTcon = tlink_tcon(tlink);
596 
597 	full_path = build_path_from_dentry(direntry, page);
598 	if (IS_ERR(full_path)) {
599 		rc = PTR_ERR(full_path);
600 		goto symlink_exit;
601 	}
602 
603 	cifs_dbg(FYI, "Full path: %s\n", full_path);
604 	cifs_dbg(FYI, "symname is %s\n", symname);
605 
606 	/* BB what if DFS and this volume is on different share? BB */
607 	rc = -EOPNOTSUPP;
608 	switch (get_cifs_symlink_type(cifs_sb)) {
609 	case CIFS_SYMLINK_TYPE_DEFAULT:
610 		/* should not happen, get_cifs_symlink_type() resolves the default */
611 		break;
612 
613 	case CIFS_SYMLINK_TYPE_NONE:
614 		break;
615 
616 	case CIFS_SYMLINK_TYPE_UNIX:
617 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
618 		if (pTcon->unix_ext) {
619 			rc = CIFSUnixCreateSymLink(xid, pTcon, full_path,
620 						   symname,
621 						   cifs_sb->local_nls,
622 						   cifs_remap(cifs_sb));
623 		}
624 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
625 		break;
626 
627 	case CIFS_SYMLINK_TYPE_MFSYMLINKS:
628 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) {
629 			rc = create_mf_symlink(xid, pTcon, cifs_sb,
630 					       full_path, symname);
631 		}
632 		break;
633 
634 	case CIFS_SYMLINK_TYPE_SFU:
635 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
636 			rc = __cifs_sfu_make_node(xid, inode, direntry, pTcon,
637 						  full_path, S_IFLNK,
638 						  0, symname);
639 		}
640 		break;
641 
642 	case CIFS_SYMLINK_TYPE_NATIVE:
643 	case CIFS_SYMLINK_TYPE_NFS:
644 	case CIFS_SYMLINK_TYPE_WSL:
645 		if (le32_to_cpu(pTcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS) {
646 			rc = create_reparse_symlink(xid, inode, direntry, pTcon,
647 						    full_path, symname);
648 			goto symlink_exit;
649 		}
650 		break;
651 	}
652 
653 	if (rc == 0) {
654 		if (pTcon->posix_extensions) {
655 			rc = smb311_posix_get_inode_info(&newinode, full_path,
656 							 NULL, inode->i_sb, xid);
657 		} else if (pTcon->unix_ext) {
658 			rc = cifs_get_inode_info_unix(&newinode, full_path,
659 						      inode->i_sb, xid);
660 		} else {
661 			rc = cifs_get_inode_info(&newinode, full_path, NULL,
662 						 inode->i_sb, xid, NULL);
663 		}
664 
665 		if (rc != 0) {
666 			cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
667 				 rc);
668 		} else {
669 			d_instantiate(direntry, newinode);
670 		}
671 	}
672 symlink_exit:
673 	free_dentry_path(page);
674 	cifs_put_tlink(tlink);
675 	free_xid(xid);
676 	return rc;
677 }
678