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 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
101 return -EINVAL;
102
103 rc = symlink_hash(link_len, link_str, md5_hash);
104 if (rc) {
105 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
106 return rc;
107 }
108
109 snprintf(md5_str2, sizeof(md5_str2),
110 CIFS_MF_SYMLINK_MD5_FORMAT,
111 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
112
113 if (strncmp(md5_str1, md5_str2, 17) != 0)
114 return -EINVAL;
115
116 if (_link_str) {
117 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
118 if (!*_link_str)
119 return -ENOMEM;
120 }
121
122 *_link_len = link_len;
123 return 0;
124 }
125
126 static int
format_mf_symlink(u8 * buf,unsigned int buf_len,const char * link_str)127 format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
128 {
129 int rc;
130 unsigned int link_len;
131 unsigned int ofs;
132 u8 md5_hash[16];
133
134 if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
135 return -EINVAL;
136
137 link_len = strlen(link_str);
138
139 if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
140 return -ENAMETOOLONG;
141
142 rc = symlink_hash(link_len, link_str, md5_hash);
143 if (rc) {
144 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
145 return rc;
146 }
147
148 snprintf(buf, buf_len,
149 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
150 link_len,
151 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
152
153 ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
154 memcpy(buf + ofs, link_str, link_len);
155
156 ofs += link_len;
157 if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
158 buf[ofs] = '\n';
159 ofs++;
160 }
161
162 while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
163 buf[ofs] = ' ';
164 ofs++;
165 }
166
167 return 0;
168 }
169
170 bool
couldbe_mf_symlink(const struct cifs_fattr * fattr)171 couldbe_mf_symlink(const struct cifs_fattr *fattr)
172 {
173 if (!S_ISREG(fattr->cf_mode))
174 /* it's not a symlink */
175 return false;
176
177 if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
178 /* it's not a symlink */
179 return false;
180
181 return true;
182 }
183
184 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)185 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
186 struct cifs_sb_info *cifs_sb, const char *fromName,
187 const char *toName)
188 {
189 int rc;
190 u8 *buf;
191 unsigned int bytes_written = 0;
192
193 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
194 if (!buf)
195 return -ENOMEM;
196
197 rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
198 if (rc)
199 goto out;
200
201 if (tcon->ses->server->ops->create_mf_symlink)
202 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
203 cifs_sb, fromName, buf, &bytes_written);
204 else
205 rc = -EOPNOTSUPP;
206
207 if (rc)
208 goto out;
209
210 if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
211 rc = -EIO;
212 out:
213 kfree(buf);
214 return rc;
215 }
216
217 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)218 query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
219 struct cifs_sb_info *cifs_sb, const unsigned char *path,
220 char **symlinkinfo)
221 {
222 int rc;
223 u8 *buf = NULL;
224 unsigned int link_len = 0;
225 unsigned int bytes_read = 0;
226
227 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
228 if (!buf)
229 return -ENOMEM;
230
231 if (tcon->ses->server->ops->query_mf_symlink)
232 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
233 cifs_sb, path, buf, &bytes_read);
234 else
235 rc = -ENOSYS;
236
237 if (rc)
238 goto out;
239
240 if (bytes_read == 0) { /* not a symlink */
241 rc = -EINVAL;
242 goto out;
243 }
244
245 rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
246 out:
247 kfree(buf);
248 return rc;
249 }
250
251 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)252 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
253 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
254 const unsigned char *path)
255 {
256 int rc;
257 u8 *buf = NULL;
258 unsigned int link_len = 0;
259 unsigned int bytes_read = 0;
260
261 if (!couldbe_mf_symlink(fattr))
262 /* it's not a symlink */
263 return 0;
264
265 buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
266 if (!buf)
267 return -ENOMEM;
268
269 if (tcon->ses->server->ops->query_mf_symlink)
270 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
271 cifs_sb, path, buf, &bytes_read);
272 else
273 rc = -ENOSYS;
274
275 if (rc)
276 goto out;
277
278 if (bytes_read == 0) /* not a symlink */
279 goto out;
280
281 rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
282 if (rc == -EINVAL) {
283 /* it's not a symlink */
284 rc = 0;
285 goto out;
286 }
287
288 if (rc != 0)
289 goto out;
290
291 /* it is a symlink */
292 fattr->cf_eof = link_len;
293 fattr->cf_mode &= ~S_IFMT;
294 fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
295 fattr->cf_dtype = DT_LNK;
296 out:
297 kfree(buf);
298 return rc;
299 }
300
301 /*
302 * SMB 1.0 Protocol specific functions
303 */
304
305 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)306 cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
307 struct cifs_sb_info *cifs_sb, const unsigned char *path,
308 char *pbuf, unsigned int *pbytes_read)
309 {
310 int rc;
311 int oplock = 0;
312 struct cifs_fid fid;
313 struct cifs_open_parms oparms;
314 struct cifs_io_parms io_parms;
315 int buf_type = CIFS_NO_BUFFER;
316 FILE_ALL_INFO file_info;
317
318 oparms.tcon = tcon;
319 oparms.cifs_sb = cifs_sb;
320 oparms.desired_access = GENERIC_READ;
321 oparms.create_options = CREATE_NOT_DIR;
322 oparms.disposition = FILE_OPEN;
323 oparms.path = path;
324 oparms.fid = &fid;
325 oparms.reconnect = false;
326
327 rc = CIFS_open(xid, &oparms, &oplock, &file_info);
328 if (rc)
329 return rc;
330
331 if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
332 rc = -ENOENT;
333 /* it's not a symlink */
334 goto out;
335 }
336
337 io_parms.netfid = fid.netfid;
338 io_parms.pid = current->tgid;
339 io_parms.tcon = tcon;
340 io_parms.offset = 0;
341 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
342
343 rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
344 out:
345 CIFSSMBClose(xid, tcon, fid.netfid);
346 return rc;
347 }
348
349 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)350 cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
351 struct cifs_sb_info *cifs_sb, const unsigned char *path,
352 char *pbuf, unsigned int *pbytes_written)
353 {
354 int rc;
355 int oplock = 0;
356 struct cifs_fid fid;
357 struct cifs_open_parms oparms;
358 struct cifs_io_parms io_parms;
359 int create_options = CREATE_NOT_DIR;
360
361 if (backup_cred(cifs_sb))
362 create_options |= CREATE_OPEN_BACKUP_INTENT;
363
364 oparms.tcon = tcon;
365 oparms.cifs_sb = cifs_sb;
366 oparms.desired_access = GENERIC_WRITE;
367 oparms.create_options = create_options;
368 oparms.disposition = FILE_CREATE;
369 oparms.path = path;
370 oparms.fid = &fid;
371 oparms.reconnect = false;
372
373 rc = CIFS_open(xid, &oparms, &oplock, NULL);
374 if (rc)
375 return rc;
376
377 io_parms.netfid = fid.netfid;
378 io_parms.pid = current->tgid;
379 io_parms.tcon = tcon;
380 io_parms.offset = 0;
381 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
382
383 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
384 CIFSSMBClose(xid, tcon, fid.netfid);
385 return rc;
386 }
387
388 /*
389 * SMB 2.1/SMB3 Protocol specific functions
390 */
391 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)392 smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
393 struct cifs_sb_info *cifs_sb, const unsigned char *path,
394 char *pbuf, unsigned int *pbytes_read)
395 {
396 int rc;
397 struct cifs_fid fid;
398 struct cifs_open_parms oparms;
399 struct cifs_io_parms io_parms;
400 int buf_type = CIFS_NO_BUFFER;
401 __le16 *utf16_path;
402 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
403 struct smb2_file_all_info *pfile_info = NULL;
404
405 oparms.tcon = tcon;
406 oparms.cifs_sb = cifs_sb;
407 oparms.desired_access = GENERIC_READ;
408 oparms.create_options = CREATE_NOT_DIR;
409 if (backup_cred(cifs_sb))
410 oparms.create_options |= CREATE_OPEN_BACKUP_INTENT;
411 oparms.disposition = FILE_OPEN;
412 oparms.fid = &fid;
413 oparms.reconnect = false;
414
415 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
416 if (utf16_path == NULL)
417 return -ENOMEM;
418
419 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
420 GFP_KERNEL);
421
422 if (pfile_info == NULL) {
423 kfree(utf16_path);
424 return -ENOMEM;
425 }
426
427 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
428 NULL);
429 if (rc)
430 goto qmf_out_open_fail;
431
432 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
433 /* it's not a symlink */
434 rc = -ENOENT; /* Is there a better rc to return? */
435 goto qmf_out;
436 }
437
438 io_parms.netfid = fid.netfid;
439 io_parms.pid = current->tgid;
440 io_parms.tcon = tcon;
441 io_parms.offset = 0;
442 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
443 io_parms.persistent_fid = fid.persistent_fid;
444 io_parms.volatile_fid = fid.volatile_fid;
445 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
446 qmf_out:
447 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
448 qmf_out_open_fail:
449 kfree(utf16_path);
450 kfree(pfile_info);
451 return rc;
452 }
453
454 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)455 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
456 struct cifs_sb_info *cifs_sb, const unsigned char *path,
457 char *pbuf, unsigned int *pbytes_written)
458 {
459 int rc;
460 struct cifs_fid fid;
461 struct cifs_open_parms oparms;
462 struct cifs_io_parms io_parms;
463 int create_options = CREATE_NOT_DIR;
464 __le16 *utf16_path;
465 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
466 struct kvec iov[2];
467
468 if (backup_cred(cifs_sb))
469 create_options |= CREATE_OPEN_BACKUP_INTENT;
470
471 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
472
473 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
474 if (!utf16_path)
475 return -ENOMEM;
476
477 oparms.tcon = tcon;
478 oparms.cifs_sb = cifs_sb;
479 oparms.desired_access = GENERIC_WRITE;
480 oparms.create_options = create_options;
481 oparms.disposition = FILE_CREATE;
482 oparms.fid = &fid;
483 oparms.reconnect = false;
484 oparms.mode = 0644;
485
486 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
487 NULL);
488 if (rc) {
489 kfree(utf16_path);
490 return rc;
491 }
492
493 io_parms.netfid = fid.netfid;
494 io_parms.pid = current->tgid;
495 io_parms.tcon = tcon;
496 io_parms.offset = 0;
497 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
498 io_parms.persistent_fid = fid.persistent_fid;
499 io_parms.volatile_fid = fid.volatile_fid;
500
501 /* iov[0] is reserved for smb header */
502 iov[1].iov_base = pbuf;
503 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
504
505 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
506
507 /* Make sure we wrote all of the symlink data */
508 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
509 rc = -EIO;
510
511 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
512
513 kfree(utf16_path);
514 return rc;
515 }
516
517 /*
518 * M-F Symlink Functions - End
519 */
520
521 int
cifs_hardlink(struct dentry * old_file,struct inode * inode,struct dentry * direntry)522 cifs_hardlink(struct dentry *old_file, struct inode *inode,
523 struct dentry *direntry)
524 {
525 int rc = -EACCES;
526 unsigned int xid;
527 char *from_name = NULL;
528 char *to_name = NULL;
529 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
530 struct tcon_link *tlink;
531 struct cifs_tcon *tcon;
532 struct TCP_Server_Info *server;
533 struct cifsInodeInfo *cifsInode;
534
535 tlink = cifs_sb_tlink(cifs_sb);
536 if (IS_ERR(tlink))
537 return PTR_ERR(tlink);
538 tcon = tlink_tcon(tlink);
539
540 xid = get_xid();
541
542 from_name = build_path_from_dentry(old_file);
543 to_name = build_path_from_dentry(direntry);
544 if ((from_name == NULL) || (to_name == NULL)) {
545 rc = -ENOMEM;
546 goto cifs_hl_exit;
547 }
548
549 if (tcon->unix_ext)
550 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
551 cifs_sb->local_nls,
552 cifs_remap(cifs_sb));
553 else {
554 server = tcon->ses->server;
555 if (!server->ops->create_hardlink) {
556 rc = -ENOSYS;
557 goto cifs_hl_exit;
558 }
559 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
560 cifs_sb);
561 if ((rc == -EIO) || (rc == -EINVAL))
562 rc = -EOPNOTSUPP;
563 }
564
565 d_drop(direntry); /* force new lookup from server of target */
566
567 /*
568 * if source file is cached (oplocked) revalidate will not go to server
569 * until the file is closed or oplock broken so update nlinks locally
570 */
571 if (d_really_is_positive(old_file)) {
572 cifsInode = CIFS_I(d_inode(old_file));
573 if (rc == 0) {
574 spin_lock(&d_inode(old_file)->i_lock);
575 inc_nlink(d_inode(old_file));
576 spin_unlock(&d_inode(old_file)->i_lock);
577
578 /*
579 * parent dir timestamps will update from srv within a
580 * second, would it really be worth it to set the parent
581 * dir cifs inode time to zero to force revalidate
582 * (faster) for it too?
583 */
584 }
585 /*
586 * if not oplocked will force revalidate to get info on source
587 * file from srv. Note Samba server prior to 4.2 has bug -
588 * not updating src file ctime on hardlinks but Windows servers
589 * handle it properly
590 */
591 cifsInode->time = 0;
592
593 /*
594 * Will update parent dir timestamps from srv within a second.
595 * Would it really be worth it to set the parent dir (cifs
596 * inode) time field to zero to force revalidate on parent
597 * directory faster ie
598 *
599 * CIFS_I(inode)->time = 0;
600 */
601 }
602
603 cifs_hl_exit:
604 kfree(from_name);
605 kfree(to_name);
606 free_xid(xid);
607 cifs_put_tlink(tlink);
608 return rc;
609 }
610
611 const char *
cifs_get_link(struct dentry * direntry,struct inode * inode,struct delayed_call * done)612 cifs_get_link(struct dentry *direntry, struct inode *inode,
613 struct delayed_call *done)
614 {
615 int rc = -ENOMEM;
616 unsigned int xid;
617 char *full_path = NULL;
618 char *target_path = NULL;
619 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
620 struct tcon_link *tlink = NULL;
621 struct cifs_tcon *tcon;
622 struct TCP_Server_Info *server;
623
624 if (!direntry)
625 return ERR_PTR(-ECHILD);
626
627 xid = get_xid();
628
629 tlink = cifs_sb_tlink(cifs_sb);
630 if (IS_ERR(tlink)) {
631 free_xid(xid);
632 return ERR_CAST(tlink);
633 }
634 tcon = tlink_tcon(tlink);
635 server = tcon->ses->server;
636
637 full_path = build_path_from_dentry(direntry);
638 if (!full_path) {
639 free_xid(xid);
640 cifs_put_tlink(tlink);
641 return ERR_PTR(-ENOMEM);
642 }
643
644 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
645
646 rc = -EACCES;
647 /*
648 * First try Minshall+French Symlinks, if configured
649 * and fallback to UNIX Extensions Symlinks.
650 */
651 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
652 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
653 &target_path);
654
655 if (rc != 0 && server->ops->query_symlink)
656 rc = server->ops->query_symlink(xid, tcon, full_path,
657 &target_path, cifs_sb);
658
659 kfree(full_path);
660 free_xid(xid);
661 cifs_put_tlink(tlink);
662 if (rc != 0) {
663 kfree(target_path);
664 return ERR_PTR(rc);
665 }
666 set_delayed_call(done, kfree_link, target_path);
667 return target_path;
668 }
669
670 int
cifs_symlink(struct inode * inode,struct dentry * direntry,const char * symname)671 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
672 {
673 int rc = -EOPNOTSUPP;
674 unsigned int xid;
675 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
676 struct tcon_link *tlink;
677 struct cifs_tcon *pTcon;
678 char *full_path = NULL;
679 struct inode *newinode = NULL;
680
681 xid = get_xid();
682
683 tlink = cifs_sb_tlink(cifs_sb);
684 if (IS_ERR(tlink)) {
685 rc = PTR_ERR(tlink);
686 goto symlink_exit;
687 }
688 pTcon = tlink_tcon(tlink);
689
690 full_path = build_path_from_dentry(direntry);
691 if (full_path == NULL) {
692 rc = -ENOMEM;
693 goto symlink_exit;
694 }
695
696 cifs_dbg(FYI, "Full path: %s\n", full_path);
697 cifs_dbg(FYI, "symname is %s\n", symname);
698
699 /* BB what if DFS and this volume is on different share? BB */
700 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
701 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
702 else if (pTcon->unix_ext)
703 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
704 cifs_sb->local_nls,
705 cifs_remap(cifs_sb));
706 /* else
707 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
708 cifs_sb_target->local_nls); */
709
710 if (rc == 0) {
711 if (pTcon->unix_ext)
712 rc = cifs_get_inode_info_unix(&newinode, full_path,
713 inode->i_sb, xid);
714 else
715 rc = cifs_get_inode_info(&newinode, full_path, NULL,
716 inode->i_sb, xid, NULL);
717
718 if (rc != 0) {
719 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
720 rc);
721 } else {
722 d_instantiate(direntry, newinode);
723 }
724 }
725 symlink_exit:
726 kfree(full_path);
727 cifs_put_tlink(tlink);
728 free_xid(xid);
729 return rc;
730 }
731