1 /*
2 * fs/cifs/link.c
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21 #include <linux/fs.h>
22 #include <linux/stat.h>
23 #include <linux/slab.h>
24 #include <linux/namei.h>
25 #include "cifsfs.h"
26 #include "cifspdu.h"
27 #include "cifsglob.h"
28 #include "cifsproto.h"
29 #include "cifs_debug.h"
30 #include "cifs_fs_sb.h"
31 #include "cifs_unicode.h"
32 #include "smb2proto.h"
33
34 /*
35 * M-F Symlink Functions - Begin
36 */
37
38 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
39 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
40 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
41 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
42 #define CIFS_MF_SYMLINK_FILE_SIZE \
43 (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
44
45 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
46 #define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
47 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
48
49 static int
symlink_hash(unsigned int link_len,const char * link_str,u8 * md5_hash)50 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
51 {
52 int rc;
53 struct crypto_shash *md5 = NULL;
54 struct sdesc *sdescmd5 = NULL;
55
56 rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
57 if (rc)
58 goto symlink_hash_err;
59
60 rc = crypto_shash_init(&sdescmd5->shash);
61 if (rc) {
62 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
63 goto symlink_hash_err;
64 }
65 rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
66 if (rc) {
67 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
68 goto symlink_hash_err;
69 }
70 rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
71 if (rc)
72 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
73
74 symlink_hash_err:
75 cifs_free_hash(&md5, &sdescmd5);
76 return rc;
77 }
78
79 static int
parse_mf_symlink(const u8 * buf,unsigned int buf_len,unsigned int * _link_len,char ** _link_str)80 parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
81 char **_link_str)
82 {
83 int rc;
84 unsigned int link_len;
85 const char *md5_str1;
86 const char *link_str;
87 u8 md5_hash[16];
88 char md5_str2[34];
89
90 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
91 return -EINVAL;
92
93 md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
94 link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
95
96 rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
97 if (rc != 1)
98 return -EINVAL;
99
100 rc = symlink_hash(link_len, link_str, md5_hash);
101 if (rc) {
102 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
103 return rc;
104 }
105
106 scnprintf(md5_str2, sizeof(md5_str2),
107 CIFS_MF_SYMLINK_MD5_FORMAT,
108 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
109
110 if (strncmp(md5_str1, md5_str2, 17) != 0)
111 return -EINVAL;
112
113 if (_link_str) {
114 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
115 if (!*_link_str)
116 return -ENOMEM;
117 }
118
119 *_link_len = link_len;
120 return 0;
121 }
122
123 static int
format_mf_symlink(u8 * buf,unsigned int buf_len,const char * link_str)124 format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
125 {
126 int rc;
127 unsigned int link_len;
128 unsigned int ofs;
129 u8 md5_hash[16];
130
131 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
132 return -EINVAL;
133
134 link_len = strlen(link_str);
135
136 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
137 return -ENAMETOOLONG;
138
139 rc = symlink_hash(link_len, link_str, md5_hash);
140 if (rc) {
141 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
142 return rc;
143 }
144
145 scnprintf(buf, buf_len,
146 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
147 link_len,
148 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
149
150 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
151 memcpy(buf + ofs, link_str, link_len);
152
153 ofs += link_len;
154 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
155 buf[ofs] = '\n';
156 ofs++;
157 }
158
159 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
160 buf[ofs] = ' ';
161 ofs++;
162 }
163
164 return 0;
165 }
166
167 bool
couldbe_mf_symlink(const struct cifs_fattr * fattr)168 couldbe_mf_symlink(const struct cifs_fattr *fattr)
169 {
170 if (!S_ISREG(fattr->cf_mode))
171 /* it's not a symlink */
172 return false;
173
174 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
175 /* it's not a symlink */
176 return false;
177
178 return true;
179 }
180
181 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)182 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
183 struct cifs_sb_info *cifs_sb, const char *fromName,
184 const char *toName)
185 {
186 int rc;
187 u8 *buf;
188 unsigned int bytes_written = 0;
189
190 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
191 if (!buf)
192 return -ENOMEM;
193
194 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
195 if (rc)
196 goto out;
197
198 if (tcon->ses->server->ops->create_mf_symlink)
199 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
200 cifs_sb, fromName, buf, &bytes_written);
201 else
202 rc = -EOPNOTSUPP;
203
204 if (rc)
205 goto out;
206
207 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
208 rc = -EIO;
209 out:
210 kfree(buf);
211 return rc;
212 }
213
214 static int
query_mf_symlink(const unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const unsigned char * path,char ** symlinkinfo)215 query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
216 struct cifs_sb_info *cifs_sb, const unsigned char *path,
217 char **symlinkinfo)
218 {
219 int rc;
220 u8 *buf = NULL;
221 unsigned int link_len = 0;
222 unsigned int bytes_read = 0;
223
224 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
225 if (!buf)
226 return -ENOMEM;
227
228 if (tcon->ses->server->ops->query_mf_symlink)
229 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
230 cifs_sb, path, buf, &bytes_read);
231 else
232 rc = -ENOSYS;
233
234 if (rc)
235 goto out;
236
237 if (bytes_read == 0) { /* not a symlink */
238 rc = -EINVAL;
239 goto out;
240 }
241
242 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
243 out:
244 kfree(buf);
245 return rc;
246 }
247
248 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)249 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
250 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
251 const unsigned char *path)
252 {
253 int rc;
254 u8 *buf = NULL;
255 unsigned int link_len = 0;
256 unsigned int bytes_read = 0;
257
258 if (!couldbe_mf_symlink(fattr))
259 /* it's not a symlink */
260 return 0;
261
262 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
263 if (!buf)
264 return -ENOMEM;
265
266 if (tcon->ses->server->ops->query_mf_symlink)
267 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
268 cifs_sb, path, buf, &bytes_read);
269 else
270 rc = -ENOSYS;
271
272 if (rc)
273 goto out;
274
275 if (bytes_read == 0) /* not a symlink */
276 goto out;
277
278 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
279 if (rc == -EINVAL) {
280 /* it's not a symlink */
281 rc = 0;
282 goto out;
283 }
284
285 if (rc != 0)
286 goto out;
287
288 /* it is a symlink */
289 fattr->cf_eof = link_len;
290 fattr->cf_mode &= ~S_IFMT;
291 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
292 fattr->cf_dtype = DT_LNK;
293 out:
294 kfree(buf);
295 return rc;
296 }
297
298 /*
299 * SMB 1.0 Protocol specific functions
300 */
301
302 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)303 cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
304 struct cifs_sb_info *cifs_sb, const unsigned char *path,
305 char *pbuf, unsigned int *pbytes_read)
306 {
307 int rc;
308 int oplock = 0;
309 struct cifs_fid fid;
310 struct cifs_open_parms oparms;
311 struct cifs_io_parms io_parms;
312 int buf_type = CIFS_NO_BUFFER;
313 FILE_ALL_INFO file_info;
314
315 oparms.tcon = tcon;
316 oparms.cifs_sb = cifs_sb;
317 oparms.desired_access = GENERIC_READ;
318 oparms.create_options = CREATE_NOT_DIR;
319 oparms.disposition = FILE_OPEN;
320 oparms.path = path;
321 oparms.fid = &fid;
322 oparms.reconnect = false;
323
324 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
325 if (rc)
326 return rc;
327
328 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
329 rc = -ENOENT;
330 /* it's not a symlink */
331 goto out;
332 }
333
334 io_parms.netfid = fid.netfid;
335 io_parms.pid = current->tgid;
336 io_parms.tcon = tcon;
337 io_parms.offset = 0;
338 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
339
340 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
341 out:
342 CIFSSMBClose(xid, tcon, fid.netfid);
343 return rc;
344 }
345
346 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)347 cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
348 struct cifs_sb_info *cifs_sb, const unsigned char *path,
349 char *pbuf, unsigned int *pbytes_written)
350 {
351 int rc;
352 int oplock = 0;
353 struct cifs_fid fid;
354 struct cifs_open_parms oparms;
355 struct cifs_io_parms io_parms;
356 int create_options = CREATE_NOT_DIR;
357
358 if (backup_cred(cifs_sb))
359 create_options |= CREATE_OPEN_BACKUP_INTENT;
360
361 oparms.tcon = tcon;
362 oparms.cifs_sb = cifs_sb;
363 oparms.desired_access = GENERIC_WRITE;
364 oparms.create_options = create_options;
365 oparms.disposition = FILE_CREATE;
366 oparms.path = path;
367 oparms.fid = &fid;
368 oparms.reconnect = false;
369
370 rc = CIFS_open(xid, &oparms, &oplock, NULL);
371 if (rc)
372 return rc;
373
374 io_parms.netfid = fid.netfid;
375 io_parms.pid = current->tgid;
376 io_parms.tcon = tcon;
377 io_parms.offset = 0;
378 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
379
380 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
381 CIFSSMBClose(xid, tcon, fid.netfid);
382 return rc;
383 }
384
385 /*
386 * SMB 2.1/SMB3 Protocol specific functions
387 */
388 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)389 smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
390 struct cifs_sb_info *cifs_sb, const unsigned char *path,
391 char *pbuf, unsigned int *pbytes_read)
392 {
393 int rc;
394 struct cifs_fid fid;
395 struct cifs_open_parms oparms;
396 struct cifs_io_parms io_parms;
397 int buf_type = CIFS_NO_BUFFER;
398 __le16 *utf16_path;
399 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
400 struct smb2_file_all_info *pfile_info = NULL;
401
402 oparms.tcon = tcon;
403 oparms.cifs_sb = cifs_sb;
404 oparms.desired_access = GENERIC_READ;
405 oparms.create_options = CREATE_NOT_DIR;
406 if (backup_cred(cifs_sb))
407 oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
408 oparms.disposition = FILE_OPEN;
409 oparms.fid = &fid;
410 oparms.reconnect = false;
411
412 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
413 if (utf16_path == NULL)
414 return -ENOMEM;
415
416 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
417 GFP_KERNEL);
418
419 if (pfile_info == NULL) {
420 kfree(utf16_path);
421 return -ENOMEM;
422 }
423
424 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
425 NULL);
426 if (rc)
427 goto qmf_out_open_fail;
428
429 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
430 /* it's not a symlink */
431 rc = -ENOENT; /* Is there a better rc to return? */
432 goto qmf_out;
433 }
434
435 io_parms.netfid = fid.netfid;
436 io_parms.pid = current->tgid;
437 io_parms.tcon = tcon;
438 io_parms.offset = 0;
439 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
440 io_parms.persistent_fid = fid.persistent_fid;
441 io_parms.volatile_fid = fid.volatile_fid;
442 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
443 qmf_out:
444 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
445 qmf_out_open_fail:
446 kfree(utf16_path);
447 kfree(pfile_info);
448 return rc;
449 }
450
451 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)452 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
453 struct cifs_sb_info *cifs_sb, const unsigned char *path,
454 char *pbuf, unsigned int *pbytes_written)
455 {
456 int rc;
457 struct cifs_fid fid;
458 struct cifs_open_parms oparms;
459 struct cifs_io_parms io_parms;
460 int create_options = CREATE_NOT_DIR;
461 __le16 *utf16_path;
462 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
463 struct kvec iov[2];
464
465 if (backup_cred(cifs_sb))
466 create_options |= CREATE_OPEN_BACKUP_INTENT;
467
468 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
469
470 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
471 if (!utf16_path)
472 return -ENOMEM;
473
474 oparms.tcon = tcon;
475 oparms.cifs_sb = cifs_sb;
476 oparms.desired_access = GENERIC_WRITE;
477 oparms.create_options = create_options;
478 oparms.disposition = FILE_CREATE;
479 oparms.fid = &fid;
480 oparms.reconnect = false;
481
482 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
483 NULL);
484 if (rc) {
485 kfree(utf16_path);
486 return rc;
487 }
488
489 io_parms.netfid = fid.netfid;
490 io_parms.pid = current->tgid;
491 io_parms.tcon = tcon;
492 io_parms.offset = 0;
493 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
494 io_parms.persistent_fid = fid.persistent_fid;
495 io_parms.volatile_fid = fid.volatile_fid;
496
497 /* iov[0] is reserved for smb header */
498 iov[1].iov_base = pbuf;
499 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
500
501 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
502
503 /* Make sure we wrote all of the symlink data */
504 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
505 rc = -EIO;
506
507 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
508
509 kfree(utf16_path);
510 return rc;
511 }
512
513 /*
514 * M-F Symlink Functions - End
515 */
516
517 int
cifs_hardlink(struct dentry * old_file,struct inode * inode,struct dentry * direntry)518 cifs_hardlink(struct dentry *old_file, struct inode *inode,
519 struct dentry *direntry)
520 {
521 int rc = -EACCES;
522 unsigned int xid;
523 char *from_name = NULL;
524 char *to_name = NULL;
525 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
526 struct tcon_link *tlink;
527 struct cifs_tcon *tcon;
528 struct TCP_Server_Info *server;
529 struct cifsInodeInfo *cifsInode;
530
531 tlink = cifs_sb_tlink(cifs_sb);
532 if (IS_ERR(tlink))
533 return PTR_ERR(tlink);
534 tcon = tlink_tcon(tlink);
535
536 xid = get_xid();
537
538 from_name = build_path_from_dentry(old_file);
539 to_name = build_path_from_dentry(direntry);
540 if ((from_name == NULL) || (to_name == NULL)) {
541 rc = -ENOMEM;
542 goto cifs_hl_exit;
543 }
544
545 if (tcon->unix_ext)
546 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
547 cifs_sb->local_nls,
548 cifs_remap(cifs_sb));
549 else {
550 server = tcon->ses->server;
551 if (!server->ops->create_hardlink) {
552 rc = -ENOSYS;
553 goto cifs_hl_exit;
554 }
555 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
556 cifs_sb);
557 if ((rc == -EIO) || (rc == -EINVAL))
558 rc = -EOPNOTSUPP;
559 }
560
561 d_drop(direntry); /* force new lookup from server of target */
562
563 /*
564 * if source file is cached (oplocked) revalidate will not go to server
565 * until the file is closed or oplock broken so update nlinks locally
566 */
567 if (d_really_is_positive(old_file)) {
568 cifsInode = CIFS_I(d_inode(old_file));
569 if (rc == 0) {
570 spin_lock(&d_inode(old_file)->i_lock);
571 inc_nlink(d_inode(old_file));
572 spin_unlock(&d_inode(old_file)->i_lock);
573
574 /*
575 * parent dir timestamps will update from srv within a
576 * second, would it really be worth it to set the parent
577 * dir cifs inode time to zero to force revalidate
578 * (faster) for it too?
579 */
580 }
581 /*
582 * if not oplocked will force revalidate to get info on source
583 * file from srv. Note Samba server prior to 4.2 has bug -
584 * not updating src file ctime on hardlinks but Windows servers
585 * handle it properly
586 */
587 cifsInode->time = 0;
588
589 /*
590 * Will update parent dir timestamps from srv within a second.
591 * Would it really be worth it to set the parent dir (cifs
592 * inode) time field to zero to force revalidate on parent
593 * directory faster ie
594 *
595 * CIFS_I(inode)->time = 0;
596 */
597 }
598
599 cifs_hl_exit:
600 kfree(from_name);
601 kfree(to_name);
602 free_xid(xid);
603 cifs_put_tlink(tlink);
604 return rc;
605 }
606
607 const char *
cifs_get_link(struct dentry * direntry,struct inode * inode,struct delayed_call * done)608 cifs_get_link(struct dentry *direntry, struct inode *inode,
609 struct delayed_call *done)
610 {
611 int rc = -ENOMEM;
612 unsigned int xid;
613 char *full_path = NULL;
614 char *target_path = NULL;
615 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
616 struct tcon_link *tlink = NULL;
617 struct cifs_tcon *tcon;
618 struct TCP_Server_Info *server;
619
620 if (!direntry)
621 return ERR_PTR(-ECHILD);
622
623 xid = get_xid();
624
625 tlink = cifs_sb_tlink(cifs_sb);
626 if (IS_ERR(tlink)) {
627 free_xid(xid);
628 return ERR_CAST(tlink);
629 }
630 tcon = tlink_tcon(tlink);
631 server = tcon->ses->server;
632
633 full_path = build_path_from_dentry(direntry);
634 if (!full_path) {
635 free_xid(xid);
636 cifs_put_tlink(tlink);
637 return ERR_PTR(-ENOMEM);
638 }
639
640 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
641
642 rc = -EACCES;
643 /*
644 * First try Minshall+French Symlinks, if configured
645 * and fallback to UNIX Extensions Symlinks.
646 */
647 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
648 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
649 &target_path);
650
651 if (rc != 0 && server->ops->query_symlink) {
652 struct cifsInodeInfo *cifsi = CIFS_I(inode);
653 bool reparse_point = false;
654
655 if (cifsi->cifsAttrs & ATTR_REPARSE)
656 reparse_point = true;
657
658 rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
659 &target_path, reparse_point);
660 }
661
662 kfree(full_path);
663 free_xid(xid);
664 cifs_put_tlink(tlink);
665 if (rc != 0) {
666 kfree(target_path);
667 return ERR_PTR(rc);
668 }
669 set_delayed_call(done, kfree_link, target_path);
670 return target_path;
671 }
672
673 int
cifs_symlink(struct inode * inode,struct dentry * direntry,const char * symname)674 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
675 {
676 int rc = -EOPNOTSUPP;
677 unsigned int xid;
678 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
679 struct tcon_link *tlink;
680 struct cifs_tcon *pTcon;
681 char *full_path = NULL;
682 struct inode *newinode = NULL;
683
684 xid = get_xid();
685
686 tlink = cifs_sb_tlink(cifs_sb);
687 if (IS_ERR(tlink)) {
688 rc = PTR_ERR(tlink);
689 goto symlink_exit;
690 }
691 pTcon = tlink_tcon(tlink);
692
693 full_path = build_path_from_dentry(direntry);
694 if (full_path == NULL) {
695 rc = -ENOMEM;
696 goto symlink_exit;
697 }
698
699 cifs_dbg(FYI, "Full path: %s\n", full_path);
700 cifs_dbg(FYI, "symname is %s\n", symname);
701
702 /* BB what if DFS and this volume is on different share? BB */
703 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
704 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
705 else if (pTcon->unix_ext)
706 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
707 cifs_sb->local_nls,
708 cifs_remap(cifs_sb));
709 /* else
710 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
711 cifs_sb_target->local_nls); */
712
713 if (rc == 0) {
714 if (pTcon->unix_ext)
715 rc = cifs_get_inode_info_unix(&newinode, full_path,
716 inode->i_sb, xid);
717 else
718 rc = cifs_get_inode_info(&newinode, full_path, NULL,
719 inode->i_sb, xid, NULL);
720
721 if (rc != 0) {
722 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
723 rc);
724 } else {
725 d_instantiate(direntry, newinode);
726 }
727 }
728 symlink_exit:
729 kfree(full_path);
730 cifs_put_tlink(tlink);
731 free_xid(xid);
732 return rc;
733 }
734