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 scnprintf(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 scnprintf(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 = {0};
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 = cifs_create_options(cifs_sb, 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 = {0};
359
360 oparms.tcon = tcon;
361 oparms.cifs_sb = cifs_sb;
362 oparms.desired_access = GENERIC_WRITE;
363 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
364 oparms.disposition = FILE_CREATE;
365 oparms.path = path;
366 oparms.fid = &fid;
367 oparms.reconnect = false;
368
369 rc = CIFS_open(xid, &oparms, &oplock, NULL);
370 if (rc)
371 return rc;
372
373 io_parms.netfid = fid.netfid;
374 io_parms.pid = current->tgid;
375 io_parms.tcon = tcon;
376 io_parms.offset = 0;
377 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
378
379 rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
380 CIFSSMBClose(xid, tcon, fid.netfid);
381 return rc;
382 }
383
384 /*
385 * SMB 2.1/SMB3 Protocol specific functions
386 */
387 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)388 smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
389 struct cifs_sb_info *cifs_sb, const unsigned char *path,
390 char *pbuf, unsigned int *pbytes_read)
391 {
392 int rc;
393 struct cifs_fid fid;
394 struct cifs_open_parms oparms;
395 struct cifs_io_parms io_parms = {0};
396 int buf_type = CIFS_NO_BUFFER;
397 __le16 *utf16_path;
398 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
399 struct smb2_file_all_info *pfile_info = NULL;
400
401 oparms.tcon = tcon;
402 oparms.cifs_sb = cifs_sb;
403 oparms.desired_access = GENERIC_READ;
404 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
405 oparms.disposition = FILE_OPEN;
406 oparms.fid = &fid;
407 oparms.reconnect = false;
408
409 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
410 if (utf16_path == NULL)
411 return -ENOMEM;
412
413 pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
414 GFP_KERNEL);
415
416 if (pfile_info == NULL) {
417 kfree(utf16_path);
418 return -ENOMEM;
419 }
420
421 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
422 NULL, NULL);
423 if (rc)
424 goto qmf_out_open_fail;
425
426 if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
427 /* it's not a symlink */
428 rc = -ENOENT; /* Is there a better rc to return? */
429 goto qmf_out;
430 }
431
432 io_parms.netfid = fid.netfid;
433 io_parms.pid = current->tgid;
434 io_parms.tcon = tcon;
435 io_parms.offset = 0;
436 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
437 io_parms.persistent_fid = fid.persistent_fid;
438 io_parms.volatile_fid = fid.volatile_fid;
439 rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
440 qmf_out:
441 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
442 qmf_out_open_fail:
443 kfree(utf16_path);
444 kfree(pfile_info);
445 return rc;
446 }
447
448 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)449 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
450 struct cifs_sb_info *cifs_sb, const unsigned char *path,
451 char *pbuf, unsigned int *pbytes_written)
452 {
453 int rc;
454 struct cifs_fid fid;
455 struct cifs_open_parms oparms;
456 struct cifs_io_parms io_parms = {0};
457 __le16 *utf16_path;
458 __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
459 struct kvec iov[2];
460
461 cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
462
463 utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
464 if (!utf16_path)
465 return -ENOMEM;
466
467 oparms.tcon = tcon;
468 oparms.cifs_sb = cifs_sb;
469 oparms.desired_access = GENERIC_WRITE;
470 oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
471 oparms.disposition = FILE_CREATE;
472 oparms.fid = &fid;
473 oparms.reconnect = false;
474 oparms.mode = 0644;
475
476 rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
477 NULL, NULL);
478 if (rc) {
479 kfree(utf16_path);
480 return rc;
481 }
482
483 io_parms.netfid = fid.netfid;
484 io_parms.pid = current->tgid;
485 io_parms.tcon = tcon;
486 io_parms.offset = 0;
487 io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
488 io_parms.persistent_fid = fid.persistent_fid;
489 io_parms.volatile_fid = fid.volatile_fid;
490
491 /* iov[0] is reserved for smb header */
492 iov[1].iov_base = pbuf;
493 iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
494
495 rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
496
497 /* Make sure we wrote all of the symlink data */
498 if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
499 rc = -EIO;
500
501 SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
502
503 kfree(utf16_path);
504 return rc;
505 }
506
507 /*
508 * M-F Symlink Functions - End
509 */
510
511 int
cifs_hardlink(struct dentry * old_file,struct inode * inode,struct dentry * direntry)512 cifs_hardlink(struct dentry *old_file, struct inode *inode,
513 struct dentry *direntry)
514 {
515 int rc = -EACCES;
516 unsigned int xid;
517 char *from_name = NULL;
518 char *to_name = NULL;
519 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
520 struct tcon_link *tlink;
521 struct cifs_tcon *tcon;
522 struct TCP_Server_Info *server;
523 struct cifsInodeInfo *cifsInode;
524
525 tlink = cifs_sb_tlink(cifs_sb);
526 if (IS_ERR(tlink))
527 return PTR_ERR(tlink);
528 tcon = tlink_tcon(tlink);
529
530 xid = get_xid();
531
532 from_name = build_path_from_dentry(old_file);
533 to_name = build_path_from_dentry(direntry);
534 if ((from_name == NULL) || (to_name == NULL)) {
535 rc = -ENOMEM;
536 goto cifs_hl_exit;
537 }
538
539 if (tcon->unix_ext)
540 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
541 cifs_sb->local_nls,
542 cifs_remap(cifs_sb));
543 else {
544 server = tcon->ses->server;
545 if (!server->ops->create_hardlink) {
546 rc = -ENOSYS;
547 goto cifs_hl_exit;
548 }
549 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
550 cifs_sb);
551 if ((rc == -EIO) || (rc == -EINVAL))
552 rc = -EOPNOTSUPP;
553 }
554
555 d_drop(direntry); /* force new lookup from server of target */
556
557 /*
558 * if source file is cached (oplocked) revalidate will not go to server
559 * until the file is closed or oplock broken so update nlinks locally
560 */
561 if (d_really_is_positive(old_file)) {
562 cifsInode = CIFS_I(d_inode(old_file));
563 if (rc == 0) {
564 spin_lock(&d_inode(old_file)->i_lock);
565 inc_nlink(d_inode(old_file));
566 spin_unlock(&d_inode(old_file)->i_lock);
567
568 /*
569 * parent dir timestamps will update from srv within a
570 * second, would it really be worth it to set the parent
571 * dir cifs inode time to zero to force revalidate
572 * (faster) for it too?
573 */
574 }
575 /*
576 * if not oplocked will force revalidate to get info on source
577 * file from srv. Note Samba server prior to 4.2 has bug -
578 * not updating src file ctime on hardlinks but Windows servers
579 * handle it properly
580 */
581 cifsInode->time = 0;
582
583 /*
584 * Will update parent dir timestamps from srv within a second.
585 * Would it really be worth it to set the parent dir (cifs
586 * inode) time field to zero to force revalidate on parent
587 * directory faster ie
588 *
589 * CIFS_I(inode)->time = 0;
590 */
591 }
592
593 cifs_hl_exit:
594 kfree(from_name);
595 kfree(to_name);
596 free_xid(xid);
597 cifs_put_tlink(tlink);
598 return rc;
599 }
600
601 const char *
cifs_get_link(struct dentry * direntry,struct inode * inode,struct delayed_call * done)602 cifs_get_link(struct dentry *direntry, struct inode *inode,
603 struct delayed_call *done)
604 {
605 int rc = -ENOMEM;
606 unsigned int xid;
607 char *full_path = NULL;
608 char *target_path = NULL;
609 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
610 struct tcon_link *tlink = NULL;
611 struct cifs_tcon *tcon;
612 struct TCP_Server_Info *server;
613
614 if (!direntry)
615 return ERR_PTR(-ECHILD);
616
617 xid = get_xid();
618
619 tlink = cifs_sb_tlink(cifs_sb);
620 if (IS_ERR(tlink)) {
621 free_xid(xid);
622 return ERR_CAST(tlink);
623 }
624 tcon = tlink_tcon(tlink);
625 server = tcon->ses->server;
626
627 full_path = build_path_from_dentry(direntry);
628 if (!full_path) {
629 free_xid(xid);
630 cifs_put_tlink(tlink);
631 return ERR_PTR(-ENOMEM);
632 }
633
634 cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
635
636 rc = -EACCES;
637 /*
638 * First try Minshall+French Symlinks, if configured
639 * and fallback to UNIX Extensions Symlinks.
640 */
641 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
642 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
643 &target_path);
644
645 if (rc != 0 && server->ops->query_symlink) {
646 struct cifsInodeInfo *cifsi = CIFS_I(inode);
647 bool reparse_point = false;
648
649 if (cifsi->cifsAttrs & ATTR_REPARSE)
650 reparse_point = true;
651
652 rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
653 &target_path, reparse_point);
654 }
655
656 kfree(full_path);
657 free_xid(xid);
658 cifs_put_tlink(tlink);
659 if (rc != 0) {
660 kfree(target_path);
661 return ERR_PTR(rc);
662 }
663 set_delayed_call(done, kfree_link, target_path);
664 return target_path;
665 }
666
667 int
cifs_symlink(struct inode * inode,struct dentry * direntry,const char * symname)668 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
669 {
670 int rc = -EOPNOTSUPP;
671 unsigned int xid;
672 struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
673 struct tcon_link *tlink;
674 struct cifs_tcon *pTcon;
675 char *full_path = NULL;
676 struct inode *newinode = NULL;
677
678 xid = get_xid();
679
680 tlink = cifs_sb_tlink(cifs_sb);
681 if (IS_ERR(tlink)) {
682 rc = PTR_ERR(tlink);
683 goto symlink_exit;
684 }
685 pTcon = tlink_tcon(tlink);
686
687 full_path = build_path_from_dentry(direntry);
688 if (full_path == NULL) {
689 rc = -ENOMEM;
690 goto symlink_exit;
691 }
692
693 cifs_dbg(FYI, "Full path: %s\n", full_path);
694 cifs_dbg(FYI, "symname is %s\n", symname);
695
696 /* BB what if DFS and this volume is on different share? BB */
697 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
698 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
699 else if (pTcon->unix_ext)
700 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
701 cifs_sb->local_nls,
702 cifs_remap(cifs_sb));
703 /* else
704 rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
705 cifs_sb_target->local_nls); */
706
707 if (rc == 0) {
708 if (pTcon->posix_extensions)
709 rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
710 else if (pTcon->unix_ext)
711 rc = cifs_get_inode_info_unix(&newinode, full_path,
712 inode->i_sb, xid);
713 else
714 rc = cifs_get_inode_info(&newinode, full_path, NULL,
715 inode->i_sb, xid, NULL);
716
717 if (rc != 0) {
718 cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
719 rc);
720 } else {
721 d_instantiate(direntry, newinode);
722 }
723 }
724 symlink_exit:
725 kfree(full_path);
726 cifs_put_tlink(tlink);
727 free_xid(xid);
728 return rc;
729 }
730