perf tools: Fix a build error on arm64 with clang
[linux-2.6-microblaze.git] / fs / cifs / link.c
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 #include "cifs_ioctl.h"
34
35 /*
36  * M-F Symlink Functions - Begin
37  */
38
39 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
40 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
41 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
42 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
43 #define CIFS_MF_SYMLINK_FILE_SIZE \
44         (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
45
46 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
47 #define CIFS_MF_SYMLINK_MD5_FORMAT "%16phN\n"
48 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) md5_hash
49
50 static int
51 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
52 {
53         int rc;
54         struct crypto_shash *md5 = NULL;
55         struct sdesc *sdescmd5 = NULL;
56
57         rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
58         if (rc)
59                 goto symlink_hash_err;
60
61         rc = crypto_shash_init(&sdescmd5->shash);
62         if (rc) {
63                 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
64                 goto symlink_hash_err;
65         }
66         rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
67         if (rc) {
68                 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
69                 goto symlink_hash_err;
70         }
71         rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
72         if (rc)
73                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
74
75 symlink_hash_err:
76         cifs_free_hash(&md5, &sdescmd5);
77         return rc;
78 }
79
80 static int
81 parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
82                  char **_link_str)
83 {
84         int rc;
85         unsigned int link_len;
86         const char *md5_str1;
87         const char *link_str;
88         u8 md5_hash[16];
89         char md5_str2[34];
90
91         if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
92                 return -EINVAL;
93
94         md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
95         link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
96
97         rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
98         if (rc != 1)
99                 return -EINVAL;
100
101         rc = symlink_hash(link_len, link_str, md5_hash);
102         if (rc) {
103                 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
104                 return rc;
105         }
106
107         scnprintf(md5_str2, sizeof(md5_str2),
108                   CIFS_MF_SYMLINK_MD5_FORMAT,
109                   CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
110
111         if (strncmp(md5_str1, md5_str2, 17) != 0)
112                 return -EINVAL;
113
114         if (_link_str) {
115                 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
116                 if (!*_link_str)
117                         return -ENOMEM;
118         }
119
120         *_link_len = link_len;
121         return 0;
122 }
123
124 static int
125 format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
126 {
127         int rc;
128         unsigned int link_len;
129         unsigned int ofs;
130         u8 md5_hash[16];
131
132         if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
133                 return -EINVAL;
134
135         link_len = strlen(link_str);
136
137         if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
138                 return -ENAMETOOLONG;
139
140         rc = symlink_hash(link_len, link_str, md5_hash);
141         if (rc) {
142                 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
143                 return rc;
144         }
145
146         scnprintf(buf, buf_len,
147                   CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
148                   link_len,
149                   CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
150
151         ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
152         memcpy(buf + ofs, link_str, link_len);
153
154         ofs += link_len;
155         if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
156                 buf[ofs] = '\n';
157                 ofs++;
158         }
159
160         while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
161                 buf[ofs] = ' ';
162                 ofs++;
163         }
164
165         return 0;
166 }
167
168 bool
169 couldbe_mf_symlink(const struct cifs_fattr *fattr)
170 {
171         if (!S_ISREG(fattr->cf_mode))
172                 /* it's not a symlink */
173                 return false;
174
175         if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
176                 /* it's not a symlink */
177                 return false;
178
179         return true;
180 }
181
182 static int
183 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
184                   struct cifs_sb_info *cifs_sb, const char *fromName,
185                   const char *toName)
186 {
187         int rc;
188         u8 *buf;
189         unsigned int bytes_written = 0;
190
191         buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
192         if (!buf)
193                 return -ENOMEM;
194
195         rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
196         if (rc)
197                 goto out;
198
199         if (tcon->ses->server->ops->create_mf_symlink)
200                 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
201                                         cifs_sb, fromName, buf, &bytes_written);
202         else
203                 rc = -EOPNOTSUPP;
204
205         if (rc)
206                 goto out;
207
208         if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
209                 rc = -EIO;
210 out:
211         kfree(buf);
212         return rc;
213 }
214
215 static int
216 query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
217                  struct cifs_sb_info *cifs_sb, const unsigned char *path,
218                  char **symlinkinfo)
219 {
220         int rc;
221         u8 *buf = NULL;
222         unsigned int link_len = 0;
223         unsigned int bytes_read = 0;
224
225         buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
226         if (!buf)
227                 return -ENOMEM;
228
229         if (tcon->ses->server->ops->query_mf_symlink)
230                 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
231                                               cifs_sb, path, buf, &bytes_read);
232         else
233                 rc = -ENOSYS;
234
235         if (rc)
236                 goto out;
237
238         if (bytes_read == 0) { /* not a symlink */
239                 rc = -EINVAL;
240                 goto out;
241         }
242
243         rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
244 out:
245         kfree(buf);
246         return rc;
247 }
248
249 int
250 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
251                  struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
252                  const unsigned char *path)
253 {
254         int rc;
255         u8 *buf = NULL;
256         unsigned int link_len = 0;
257         unsigned int bytes_read = 0;
258
259         if (!couldbe_mf_symlink(fattr))
260                 /* it's not a symlink */
261                 return 0;
262
263         buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
264         if (!buf)
265                 return -ENOMEM;
266
267         if (tcon->ses->server->ops->query_mf_symlink)
268                 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
269                                               cifs_sb, path, buf, &bytes_read);
270         else
271                 rc = -ENOSYS;
272
273         if (rc)
274                 goto out;
275
276         if (bytes_read == 0) /* not a symlink */
277                 goto out;
278
279         rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
280         if (rc == -EINVAL) {
281                 /* it's not a symlink */
282                 rc = 0;
283                 goto out;
284         }
285
286         if (rc != 0)
287                 goto out;
288
289         /* it is a symlink */
290         fattr->cf_eof = link_len;
291         fattr->cf_mode &= ~S_IFMT;
292         fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
293         fattr->cf_dtype = DT_LNK;
294 out:
295         kfree(buf);
296         return rc;
297 }
298
299 /*
300  * SMB 1.0 Protocol specific functions
301  */
302
303 int
304 cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
305                       struct cifs_sb_info *cifs_sb, const unsigned char *path,
306                       char *pbuf, unsigned int *pbytes_read)
307 {
308         int rc;
309         int oplock = 0;
310         struct cifs_fid fid;
311         struct cifs_open_parms oparms;
312         struct cifs_io_parms io_parms = {0};
313         int buf_type = CIFS_NO_BUFFER;
314         FILE_ALL_INFO file_info;
315
316         oparms.tcon = tcon;
317         oparms.cifs_sb = cifs_sb;
318         oparms.desired_access = GENERIC_READ;
319         oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
320         oparms.disposition = FILE_OPEN;
321         oparms.path = path;
322         oparms.fid = &fid;
323         oparms.reconnect = false;
324
325         rc = CIFS_open(xid, &oparms, &oplock, &file_info);
326         if (rc)
327                 return rc;
328
329         if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
330                 rc = -ENOENT;
331                 /* it's not a symlink */
332                 goto out;
333         }
334
335         io_parms.netfid = fid.netfid;
336         io_parms.pid = current->tgid;
337         io_parms.tcon = tcon;
338         io_parms.offset = 0;
339         io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
340
341         rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
342 out:
343         CIFSSMBClose(xid, tcon, fid.netfid);
344         return rc;
345 }
346
347 int
348 cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
349                        struct cifs_sb_info *cifs_sb, const unsigned char *path,
350                        char *pbuf, unsigned int *pbytes_written)
351 {
352         int rc;
353         int oplock = 0;
354         struct cifs_fid fid;
355         struct cifs_open_parms oparms;
356         struct cifs_io_parms io_parms = {0};
357
358         oparms.tcon = tcon;
359         oparms.cifs_sb = cifs_sb;
360         oparms.desired_access = GENERIC_WRITE;
361         oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
362         oparms.disposition = FILE_CREATE;
363         oparms.path = path;
364         oparms.fid = &fid;
365         oparms.reconnect = false;
366
367         rc = CIFS_open(xid, &oparms, &oplock, NULL);
368         if (rc)
369                 return rc;
370
371         io_parms.netfid = fid.netfid;
372         io_parms.pid = current->tgid;
373         io_parms.tcon = tcon;
374         io_parms.offset = 0;
375         io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
376
377         rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf);
378         CIFSSMBClose(xid, tcon, fid.netfid);
379         return rc;
380 }
381
382 /*
383  * SMB 2.1/SMB3 Protocol specific functions
384  */
385 int
386 smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
387                       struct cifs_sb_info *cifs_sb, const unsigned char *path,
388                       char *pbuf, unsigned int *pbytes_read)
389 {
390         int rc;
391         struct cifs_fid fid;
392         struct cifs_open_parms oparms;
393         struct cifs_io_parms io_parms = {0};
394         int buf_type = CIFS_NO_BUFFER;
395         __le16 *utf16_path;
396         __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
397         struct smb2_file_all_info *pfile_info = NULL;
398
399         oparms.tcon = tcon;
400         oparms.cifs_sb = cifs_sb;
401         oparms.desired_access = GENERIC_READ;
402         oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
403         oparms.disposition = FILE_OPEN;
404         oparms.fid = &fid;
405         oparms.reconnect = false;
406
407         utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
408         if (utf16_path == NULL)
409                 return -ENOMEM;
410
411         pfile_info = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
412                              GFP_KERNEL);
413
414         if (pfile_info == NULL) {
415                 kfree(utf16_path);
416                 return  -ENOMEM;
417         }
418
419         rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
420                        NULL, NULL);
421         if (rc)
422                 goto qmf_out_open_fail;
423
424         if (pfile_info->EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
425                 /* it's not a symlink */
426                 rc = -ENOENT; /* Is there a better rc to return? */
427                 goto qmf_out;
428         }
429
430         io_parms.netfid = fid.netfid;
431         io_parms.pid = current->tgid;
432         io_parms.tcon = tcon;
433         io_parms.offset = 0;
434         io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
435         io_parms.persistent_fid = fid.persistent_fid;
436         io_parms.volatile_fid = fid.volatile_fid;
437         rc = SMB2_read(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
438 qmf_out:
439         SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
440 qmf_out_open_fail:
441         kfree(utf16_path);
442         kfree(pfile_info);
443         return rc;
444 }
445
446 int
447 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
448                        struct cifs_sb_info *cifs_sb, const unsigned char *path,
449                        char *pbuf, unsigned int *pbytes_written)
450 {
451         int rc;
452         struct cifs_fid fid;
453         struct cifs_open_parms oparms;
454         struct cifs_io_parms io_parms = {0};
455         __le16 *utf16_path;
456         __u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
457         struct kvec iov[2];
458
459         cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
460
461         utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
462         if (!utf16_path)
463                 return -ENOMEM;
464
465         oparms.tcon = tcon;
466         oparms.cifs_sb = cifs_sb;
467         oparms.desired_access = GENERIC_WRITE;
468         oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_DIR);
469         oparms.disposition = FILE_CREATE;
470         oparms.fid = &fid;
471         oparms.reconnect = false;
472
473         rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
474                        NULL, NULL);
475         if (rc) {
476                 kfree(utf16_path);
477                 return rc;
478         }
479
480         io_parms.netfid = fid.netfid;
481         io_parms.pid = current->tgid;
482         io_parms.tcon = tcon;
483         io_parms.offset = 0;
484         io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
485         io_parms.persistent_fid = fid.persistent_fid;
486         io_parms.volatile_fid = fid.volatile_fid;
487
488         /* iov[0] is reserved for smb header */
489         iov[1].iov_base = pbuf;
490         iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
491
492         rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
493
494         /* Make sure we wrote all of the symlink data */
495         if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
496                 rc = -EIO;
497
498         SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
499
500         kfree(utf16_path);
501         return rc;
502 }
503
504 /*
505  * M-F Symlink Functions - End
506  */
507
508 int
509 cifs_hardlink(struct dentry *old_file, struct inode *inode,
510               struct dentry *direntry)
511 {
512         int rc = -EACCES;
513         unsigned int xid;
514         const char *from_name, *to_name;
515         void *page1, *page2;
516         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
517         struct tcon_link *tlink;
518         struct cifs_tcon *tcon;
519         struct TCP_Server_Info *server;
520         struct cifsInodeInfo *cifsInode;
521
522         if (unlikely(cifs_forced_shutdown(cifs_sb)))
523                 return -EIO;
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         page1 = alloc_dentry_path();
532         page2 = alloc_dentry_path();
533
534         from_name = build_path_from_dentry(old_file, page1);
535         if (IS_ERR(from_name)) {
536                 rc = PTR_ERR(from_name);
537                 goto cifs_hl_exit;
538         }
539         to_name = build_path_from_dentry(direntry, page2);
540         if (IS_ERR(to_name)) {
541                 rc = PTR_ERR(to_name);
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         free_dentry_path(page1);
601         free_dentry_path(page2);
602         free_xid(xid);
603         cifs_put_tlink(tlink);
604         return rc;
605 }
606
607 const char *
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         const char *full_path;
614         void *page;
615         char *target_path = NULL;
616         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
617         struct tcon_link *tlink = NULL;
618         struct cifs_tcon *tcon;
619         struct TCP_Server_Info *server;
620
621         if (!direntry)
622                 return ERR_PTR(-ECHILD);
623
624         xid = get_xid();
625
626         tlink = cifs_sb_tlink(cifs_sb);
627         if (IS_ERR(tlink)) {
628                 free_xid(xid);
629                 return ERR_CAST(tlink);
630         }
631         tcon = tlink_tcon(tlink);
632         server = tcon->ses->server;
633
634         page = alloc_dentry_path();
635         full_path = build_path_from_dentry(direntry, page);
636         if (IS_ERR(full_path)) {
637                 free_xid(xid);
638                 cifs_put_tlink(tlink);
639                 free_dentry_path(page);
640                 return ERR_CAST(full_path);
641         }
642
643         cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
644
645         rc = -EACCES;
646         /*
647          * First try Minshall+French Symlinks, if configured
648          * and fallback to UNIX Extensions Symlinks.
649          */
650         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
651                 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
652                                       &target_path);
653
654         if (rc != 0 && server->ops->query_symlink) {
655                 struct cifsInodeInfo *cifsi = CIFS_I(inode);
656                 bool reparse_point = false;
657
658                 if (cifsi->cifsAttrs & ATTR_REPARSE)
659                         reparse_point = true;
660
661                 rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
662                                                 &target_path, reparse_point);
663         }
664
665         free_dentry_path(page);
666         free_xid(xid);
667         cifs_put_tlink(tlink);
668         if (rc != 0) {
669                 kfree(target_path);
670                 return ERR_PTR(rc);
671         }
672         set_delayed_call(done, kfree_link, target_path);
673         return target_path;
674 }
675
676 int
677 cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
678              struct dentry *direntry, const char *symname)
679 {
680         int rc = -EOPNOTSUPP;
681         unsigned int xid;
682         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
683         struct tcon_link *tlink;
684         struct cifs_tcon *pTcon;
685         const char *full_path;
686         void *page;
687         struct inode *newinode = NULL;
688
689         if (unlikely(cifs_forced_shutdown(cifs_sb)))
690                 return -EIO;
691
692         page = alloc_dentry_path();
693         if (!page)
694                 return -ENOMEM;
695
696         xid = get_xid();
697
698         tlink = cifs_sb_tlink(cifs_sb);
699         if (IS_ERR(tlink)) {
700                 rc = PTR_ERR(tlink);
701                 goto symlink_exit;
702         }
703         pTcon = tlink_tcon(tlink);
704
705         full_path = build_path_from_dentry(direntry, page);
706         if (IS_ERR(full_path)) {
707                 rc = PTR_ERR(full_path);
708                 goto symlink_exit;
709         }
710
711         cifs_dbg(FYI, "Full path: %s\n", full_path);
712         cifs_dbg(FYI, "symname is %s\n", symname);
713
714         /* BB what if DFS and this volume is on different share? BB */
715         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
716                 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
717         else if (pTcon->unix_ext)
718                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
719                                            cifs_sb->local_nls,
720                                            cifs_remap(cifs_sb));
721         /* else
722            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
723                                         cifs_sb_target->local_nls); */
724
725         if (rc == 0) {
726                 if (pTcon->posix_extensions)
727                         rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
728                 else if (pTcon->unix_ext)
729                         rc = cifs_get_inode_info_unix(&newinode, full_path,
730                                                       inode->i_sb, xid);
731                 else
732                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
733                                                  inode->i_sb, xid, NULL);
734
735                 if (rc != 0) {
736                         cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
737                                  rc);
738                 } else {
739                         d_instantiate(direntry, newinode);
740                 }
741         }
742 symlink_exit:
743         free_dentry_path(page);
744         cifs_put_tlink(tlink);
745         free_xid(xid);
746         return rc;
747 }