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 "smb2proto.h"
  32
  33 /*
  34  * M-F Symlink Functions - Begin
  35  */
  36
  37 #define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
  38 #define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
  39 #define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
  40 #define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
  41 #define CIFS_MF_SYMLINK_FILE_SIZE \
  42         (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
  43
  44 #define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
  45 #define CIFS_MF_SYMLINK_MD5_FORMAT \
  46         "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
  47 #define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
  48         md5_hash[0],  md5_hash[1],  md5_hash[2],  md5_hash[3], \
  49         md5_hash[4],  md5_hash[5],  md5_hash[6],  md5_hash[7], \
  50         md5_hash[8],  md5_hash[9],  md5_hash[10], md5_hash[11],\
  51         md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
  52
  53 static int
  54 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
  55 {
  56         int rc;
  57         unsigned int size;
  58         struct crypto_shash *md5;
  59         struct sdesc *sdescmd5;
  60
  61         md5 = crypto_alloc_shash("md5", 0, 0);
  62         if (IS_ERR(md5)) {
  63                 rc = PTR_ERR(md5);
  64                 cifs_dbg(VFS, "%s: Crypto md5 allocation error %d\n",
  65                          __func__, rc);
  66                 return rc;
  67         }
  68         size = sizeof(struct shash_desc) + crypto_shash_descsize(md5);
  69         sdescmd5 = kmalloc(size, GFP_KERNEL);
  70         if (!sdescmd5) {
  71                 rc = -ENOMEM;
  72                 goto symlink_hash_err;
  73         }
  74         sdescmd5->shash.tfm = md5;
  75         sdescmd5->shash.flags = 0x0;
  76
  77         rc = crypto_shash_init(&sdescmd5->shash);
  78         if (rc) {
  79                 cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
  80                 goto symlink_hash_err;
  81         }
  82         rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
  83         if (rc) {
  84                 cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
  85                 goto symlink_hash_err;
  86         }
  87         rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
  88         if (rc)
  89                 cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
  90
  91 symlink_hash_err:
  92         crypto_free_shash(md5);
  93         kfree(sdescmd5);
  94
  95         return rc;
  96 }
  97
  98 static int
  99 parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
 100                  char **_link_str)
 101 {
 102         int rc;
 103         unsigned int link_len;
 104         const char *md5_str1;
 105         const char *link_str;
 106         u8 md5_hash[16];
 107         char md5_str2[34];
 108
 109         if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
 110                 return -EINVAL;
 111
 112         md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
 113         link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
 114
 115         rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
 116         if (rc != 1)
 117                 return -EINVAL;
 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         snprintf(md5_str2, sizeof(md5_str2),
 126                  CIFS_MF_SYMLINK_MD5_FORMAT,
 127                  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
 128
 129         if (strncmp(md5_str1, md5_str2, 17) != 0)
 130                 return -EINVAL;
 131
 132         if (_link_str) {
 133                 *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
 134                 if (!*_link_str)
 135                         return -ENOMEM;
 136         }
 137
 138         *_link_len = link_len;
 139         return 0;
 140 }
 141
 142 static int
 143 format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
 144 {
 145         int rc;
 146         unsigned int link_len;
 147         unsigned int ofs;
 148         u8 md5_hash[16];
 149
 150         if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
 151                 return -EINVAL;
 152
 153         link_len = strlen(link_str);
 154
 155         if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
 156                 return -ENAMETOOLONG;
 157
 158         rc = symlink_hash(link_len, link_str, md5_hash);
 159         if (rc) {
 160                 cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
 161                 return rc;
 162         }
 163
 164         snprintf(buf, buf_len,
 165                  CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
 166                  link_len,
 167                  CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
 168
 169         ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
 170         memcpy(buf + ofs, link_str, link_len);
 171
 172         ofs += link_len;
 173         if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
 174                 buf[ofs] = '\n';
 175                 ofs++;
 176         }
 177
 178         while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
 179                 buf[ofs] = ' ';
 180                 ofs++;
 181         }
 182
 183         return 0;
 184 }
 185
 186 bool
 187 couldbe_mf_symlink(const struct cifs_fattr *fattr)
 188 {
 189         if (!S_ISREG(fattr->cf_mode))
 190                 /* it's not a symlink */
 191                 return false;
 192
 193         if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
 194                 /* it's not a symlink */
 195                 return false;
 196
 197         return true;
 198 }
 199
 200 static int
 201 create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 202                   struct cifs_sb_info *cifs_sb, const char *fromName,
 203                   const char *toName)
 204 {
 205         int rc;
 206         u8 *buf;
 207         unsigned int bytes_written = 0;
 208
 209         buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
 210         if (!buf)
 211                 return -ENOMEM;
 212
 213         rc = format_mf_symlink(buf, CIFS_MF_SYMLINK_FILE_SIZE, toName);
 214         if (rc)
 215                 goto out;
 216
 217         if (tcon->ses->server->ops->create_mf_symlink)
 218                 rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
 219                                         cifs_sb, fromName, buf, &bytes_written);
 220         else
 221                 rc = -EOPNOTSUPP;
 222
 223         if (rc)
 224                 goto out;
 225
 226         if (bytes_written != CIFS_MF_SYMLINK_FILE_SIZE)
 227                 rc = -EIO;
 228 out:
 229         kfree(buf);
 230         return rc;
 231 }
 232
 233 static int
 234 query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 235                  struct cifs_sb_info *cifs_sb, const unsigned char *path,
 236                  char **symlinkinfo)
 237 {
 238         int rc;
 239         u8 *buf = NULL;
 240         unsigned int link_len = 0;
 241         unsigned int bytes_read = 0;
 242
 243         buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
 244         if (!buf)
 245                 return -ENOMEM;
 246
 247         if (tcon->ses->server->ops->query_mf_symlink)
 248                 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
 249                                               cifs_sb, path, buf, &bytes_read);
 250         else
 251                 rc = -ENOSYS;
 252
 253         if (rc)
 254                 goto out;
 255
 256         if (bytes_read == 0) { /* not a symlink */
 257                 rc = -EINVAL;
 258                 goto out;
 259         }
 260
 261         rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
 262 out:
 263         kfree(buf);
 264         return rc;
 265 }
 266
 267 int
 268 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 269                  struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 270                  const unsigned char *path)
 271 {
 272         int rc;
 273         u8 *buf = NULL;
 274         unsigned int link_len = 0;
 275         unsigned int bytes_read = 0;
 276
 277         if (!couldbe_mf_symlink(fattr))
 278                 /* it's not a symlink */
 279                 return 0;
 280
 281         buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
 282         if (!buf)
 283                 return -ENOMEM;
 284
 285         if (tcon->ses->server->ops->query_mf_symlink)
 286                 rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
 287                                               cifs_sb, path, buf, &bytes_read);
 288         else
 289                 rc = -ENOSYS;
 290
 291         if (rc)
 292                 goto out;
 293
 294         if (bytes_read == 0) /* not a symlink */
 295                 goto out;
 296
 297         rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
 298         if (rc == -EINVAL) {
 299                 /* it's not a symlink */
 300                 rc = 0;
 301                 goto out;
 302         }
 303
 304         if (rc != 0)
 305                 goto out;
 306
 307         /* it is a symlink */
 308         fattr->cf_eof = link_len;
 309         fattr->cf_mode &= ~S_IFMT;
 310         fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
 311         fattr->cf_dtype = DT_LNK;
 312 out:
 313         kfree(buf);
 314         return rc;
 315 }
 316
 317 /*
 318  * SMB 1.0 Protocol specific functions
 319  */
 320
 321 int
 322 cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 323                       struct cifs_sb_info *cifs_sb, const unsigned char *path,
 324                       char *pbuf, unsigned int *pbytes_read)
 325 {
 326         int rc;
 327         int oplock = 0;
 328         struct cifs_fid fid;
 329         struct cifs_open_parms oparms;
 330         struct cifs_io_parms io_parms;
 331         int buf_type = CIFS_NO_BUFFER;
 332         FILE_ALL_INFO file_info;
 333
 334         oparms.tcon = tcon;
 335         oparms.cifs_sb = cifs_sb;
 336         oparms.desired_access = GENERIC_READ;
 337         oparms.create_options = CREATE_NOT_DIR;
 338         oparms.disposition = FILE_OPEN;
 339         oparms.path = path;
 340         oparms.fid = &fid;
 341         oparms.reconnect = false;
 342
 343         rc = CIFS_open(xid, &oparms, &oplock, &file_info);
 344         if (rc)
 345                 return rc;
 346
 347         if (file_info.EndOfFile != cpu_to_le64(CIFS_MF_SYMLINK_FILE_SIZE)) {
 348                 rc = -ENOENT;
 349                 /* it's not a symlink */
 350                 goto out;
 351         }
 352
 353         io_parms.netfid = fid.netfid;
 354         io_parms.pid = current->tgid;
 355         io_parms.tcon = tcon;
 356         io_parms.offset = 0;
 357         io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
 358
 359         rc = CIFSSMBRead(xid, &io_parms, pbytes_read, &pbuf, &buf_type);
 360 out:
 361         CIFSSMBClose(xid, tcon, fid.netfid);
 362         return rc;
 363 }
 364
 365 int
 366 cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 367                        struct cifs_sb_info *cifs_sb, const unsigned char *path,
 368                        char *pbuf, unsigned int *pbytes_written)
 369 {
 370         int rc;
 371         int oplock = 0;
 372         struct cifs_fid fid;
 373         struct cifs_open_parms oparms;
 374         struct cifs_io_parms io_parms;
 375         int create_options = CREATE_NOT_DIR;
 376
 377         if (backup_cred(cifs_sb))
 378                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 379
 380         oparms.tcon = tcon;
 381         oparms.cifs_sb = cifs_sb;
 382         oparms.desired_access = GENERIC_WRITE;
 383         oparms.create_options = create_options;
 384         oparms.disposition = FILE_CREATE;
 385         oparms.path = path;
 386         oparms.fid = &fid;
 387         oparms.reconnect = false;
 388
 389         rc = CIFS_open(xid, &oparms, &oplock, NULL);
 390         if (rc)
 391                 return rc;
 392
 393         io_parms.netfid = fid.netfid;
 394         io_parms.pid = current->tgid;
 395         io_parms.tcon = tcon;
 396         io_parms.offset = 0;
 397         io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
 398
 399         rc = CIFSSMBWrite(xid, &io_parms, pbytes_written, pbuf, NULL, 0);
 400         CIFSSMBClose(xid, tcon, fid.netfid);
 401         return rc;
 402 }
 403
 404 int
 405 smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 406                        struct cifs_sb_info *cifs_sb, const unsigned char *path,
 407                        char *pbuf, unsigned int *pbytes_written)
 408 {
 409         int rc;
 410         struct cifs_fid fid;
 411         struct cifs_open_parms oparms;
 412         struct cifs_io_parms io_parms;
 413         int create_options = CREATE_NOT_DIR;
 414         __le16 *utf16_path;
 415         __u8 oplock = SMB2_OPLOCK_LEVEL_EXCLUSIVE;
 416         struct kvec iov[2];
 417
 418         if (backup_cred(cifs_sb))
 419                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 420
 421         cifs_dbg(FYI, "%s: path: %s\n", __func__, path);
 422
 423         utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
 424         if (!utf16_path)
 425                 return -ENOMEM;
 426
 427         oparms.tcon = tcon;
 428         oparms.cifs_sb = cifs_sb;
 429         oparms.desired_access = GENERIC_WRITE;
 430         oparms.create_options = create_options;
 431         oparms.disposition = FILE_CREATE;
 432         oparms.fid = &fid;
 433         oparms.reconnect = false;
 434
 435         rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
 436         if (rc) {
 437                 kfree(utf16_path);
 438                 return rc;
 439         }
 440
 441         io_parms.netfid = fid.netfid;
 442         io_parms.pid = current->tgid;
 443         io_parms.tcon = tcon;
 444         io_parms.offset = 0;
 445         io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
 446         io_parms.persistent_fid = fid.persistent_fid;
 447         io_parms.volatile_fid = fid.volatile_fid;
 448
 449         /* iov[0] is reserved for smb header */
 450         iov[1].iov_base = pbuf;
 451         iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
 452
 453         rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
 454
 455         /* Make sure we wrote all of the symlink data */
 456         if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
 457                 rc = -EIO;
 458
 459         SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
 460
 461         kfree(utf16_path);
 462         return rc;
 463 }
 464
 465
 466 /*
 467  * M-F Symlink Functions - End
 468  */
 469
 470 int
 471 cifs_hardlink(struct dentry *old_file, struct inode *inode,
 472               struct dentry *direntry)
 473 {
 474         int rc = -EACCES;
 475         unsigned int xid;
 476         char *from_name = NULL;
 477         char *to_name = NULL;
 478         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 479         struct tcon_link *tlink;
 480         struct cifs_tcon *tcon;
 481         struct TCP_Server_Info *server;
 482         struct cifsInodeInfo *cifsInode;
 483
 484         tlink = cifs_sb_tlink(cifs_sb);
 485         if (IS_ERR(tlink))
 486                 return PTR_ERR(tlink);
 487         tcon = tlink_tcon(tlink);
 488
 489         xid = get_xid();
 490
 491         from_name = build_path_from_dentry(old_file);
 492         to_name = build_path_from_dentry(direntry);
 493         if ((from_name == NULL) || (to_name == NULL)) {
 494                 rc = -ENOMEM;
 495                 goto cifs_hl_exit;
 496         }
 497
 498         if (tcon->unix_ext)
 499                 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
 500                                             cifs_sb->local_nls,
 501                                             cifs_sb->mnt_cifs_flags &
 502                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 503         else {
 504                 server = tcon->ses->server;
 505                 if (!server->ops->create_hardlink) {
 506                         rc = -ENOSYS;
 507                         goto cifs_hl_exit;
 508                 }
 509                 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
 510                                                   cifs_sb);
 511                 if ((rc == -EIO) || (rc == -EINVAL))
 512                         rc = -EOPNOTSUPP;
 513         }
 514
 515         d_drop(direntry);       /* force new lookup from server of target */
 516
 517         /*
 518          * if source file is cached (oplocked) revalidate will not go to server
 519          * until the file is closed or oplock broken so update nlinks locally
 520          */
 521         if (old_file->d_inode) {
 522                 cifsInode = CIFS_I(old_file->d_inode);
 523                 if (rc == 0) {
 524                         spin_lock(&old_file->d_inode->i_lock);
 525                         inc_nlink(old_file->d_inode);
 526                         spin_unlock(&old_file->d_inode->i_lock);
 527                         /*
 528                          * BB should we make this contingent on superblock flag
 529                          * NOATIME?
 530                          */
 531                         /* old_file->d_inode->i_ctime = CURRENT_TIME; */
 532                         /*
 533                          * parent dir timestamps will update from srv within a
 534                          * second, would it really be worth it to set the parent
 535                          * dir cifs inode time to zero to force revalidate
 536                          * (faster) for it too?
 537                          */
 538                 }
 539                 /*
 540                  * if not oplocked will force revalidate to get info on source
 541                  * file from srv
 542                  */
 543                 cifsInode->time = 0;
 544
 545                 /*
 546                  * Will update parent dir timestamps from srv within a second.
 547                  * Would it really be worth it to set the parent dir (cifs
 548                  * inode) time field to zero to force revalidate on parent
 549                  * directory faster ie
 550                  *
 551                  * CIFS_I(inode)->time = 0;
 552                  */
 553         }
 554
 555 cifs_hl_exit:
 556         kfree(from_name);
 557         kfree(to_name);
 558         free_xid(xid);
 559         cifs_put_tlink(tlink);
 560         return rc;
 561 }
 562
 563 void *
 564 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
 565 {
 566         struct inode *inode = direntry->d_inode;
 567         int rc = -ENOMEM;
 568         unsigned int xid;
 569         char *full_path = NULL;
 570         char *target_path = NULL;
 571         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 572         struct tcon_link *tlink = NULL;
 573         struct cifs_tcon *tcon;
 574         struct TCP_Server_Info *server;
 575
 576         xid = get_xid();
 577
 578         tlink = cifs_sb_tlink(cifs_sb);
 579         if (IS_ERR(tlink)) {
 580                 rc = PTR_ERR(tlink);
 581                 tlink = NULL;
 582                 goto out;
 583         }
 584         tcon = tlink_tcon(tlink);
 585         server = tcon->ses->server;
 586
 587         full_path = build_path_from_dentry(direntry);
 588         if (!full_path)
 589                 goto out;
 590
 591         cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
 592
 593         rc = -EACCES;
 594         /*
 595          * First try Minshall+French Symlinks, if configured
 596          * and fallback to UNIX Extensions Symlinks.
 597          */
 598         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
 599                 rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
 600                                       &target_path);
 601
 602         if (rc != 0 && server->ops->query_symlink)
 603                 rc = server->ops->query_symlink(xid, tcon, full_path,
 604                                                 &target_path, cifs_sb);
 605
 606         kfree(full_path);
 607 out:
 608         if (rc != 0) {
 609                 kfree(target_path);
 610                 target_path = ERR_PTR(rc);
 611         }
 612
 613         free_xid(xid);
 614         if (tlink)
 615                 cifs_put_tlink(tlink);
 616         nd_set_link(nd, target_path);
 617         return NULL;
 618 }
 619
 620 int
 621 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 622 {
 623         int rc = -EOPNOTSUPP;
 624         unsigned int xid;
 625         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 626         struct tcon_link *tlink;
 627         struct cifs_tcon *pTcon;
 628         char *full_path = NULL;
 629         struct inode *newinode = NULL;
 630
 631         xid = get_xid();
 632
 633         tlink = cifs_sb_tlink(cifs_sb);
 634         if (IS_ERR(tlink)) {
 635                 rc = PTR_ERR(tlink);
 636                 goto symlink_exit;
 637         }
 638         pTcon = tlink_tcon(tlink);
 639
 640         full_path = build_path_from_dentry(direntry);
 641         if (full_path == NULL) {
 642                 rc = -ENOMEM;
 643                 goto symlink_exit;
 644         }
 645
 646         cifs_dbg(FYI, "Full path: %s\n", full_path);
 647         cifs_dbg(FYI, "symname is %s\n", symname);
 648
 649         /* BB what if DFS and this volume is on different share? BB */
 650         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
 651                 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
 652         else if (pTcon->unix_ext)
 653                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
 654                                            cifs_sb->local_nls);
 655         /* else
 656            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
 657                                         cifs_sb_target->local_nls); */
 658
 659         if (rc == 0) {
 660                 if (pTcon->unix_ext)
 661                         rc = cifs_get_inode_info_unix(&newinode, full_path,
 662                                                       inode->i_sb, xid);
 663                 else
 664                         rc = cifs_get_inode_info(&newinode, full_path, NULL,
 665                                                  inode->i_sb, xid, NULL);
 666
 667                 if (rc != 0) {
 668                         cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",
 669                                  rc);
 670                 } else {
 671                         d_instantiate(direntry, newinode);
 672                 }
 673         }
 674 symlink_exit:
 675         kfree(full_path);
 676         cifs_put_tlink(tlink);
 677         free_xid(xid);
 678         return rc;
 679 }