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
  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
  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
  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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 485         rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
 486                        NULL);
 487         if (rc) {
 488                 kfree(utf16_path);
 489                 return rc;
 490         }
 491
 492         io_parms.netfid = fid.netfid;
 493         io_parms.pid = current->tgid;
 494         io_parms.tcon = tcon;
 495         io_parms.offset = 0;
 496         io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
 497         io_parms.persistent_fid = fid.persistent_fid;
 498         io_parms.volatile_fid = fid.volatile_fid;
 499
 500         /* iov[0] is reserved for smb header */
 501         iov[1].iov_base = pbuf;
 502         iov[1].iov_len = CIFS_MF_SYMLINK_FILE_SIZE;
 503
 504         rc = SMB2_write(xid, &io_parms, pbytes_written, iov, 1);
 505
 506         /* Make sure we wrote all of the symlink data */
 507         if ((rc == 0) && (*pbytes_written != CIFS_MF_SYMLINK_FILE_SIZE))
 508                 rc = -EIO;
 509
 510         SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
 511
 512         kfree(utf16_path);
 513         return rc;
 514 }
 515
 516 /*
 517  * M-F Symlink Functions - End
 518  */
 519
 520 int
 521 cifs_hardlink(struct dentry *old_file, struct inode *inode,
 522               struct dentry *direntry)
 523 {
 524         int rc = -EACCES;
 525         unsigned int xid;
 526         char *from_name = NULL;
 527         char *to_name = NULL;
 528         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 529         struct tcon_link *tlink;
 530         struct cifs_tcon *tcon;
 531         struct TCP_Server_Info *server;
 532         struct cifsInodeInfo *cifsInode;
 533
 534         tlink = cifs_sb_tlink(cifs_sb);
 535         if (IS_ERR(tlink))
 536                 return PTR_ERR(tlink);
 537         tcon = tlink_tcon(tlink);
 538
 539         xid = get_xid();
 540
 541         from_name = build_path_from_dentry(old_file);
 542         to_name = build_path_from_dentry(direntry);
 543         if ((from_name == NULL) || (to_name == NULL)) {
 544                 rc = -ENOMEM;
 545                 goto cifs_hl_exit;
 546         }
 547
 548         if (tcon->unix_ext)
 549                 rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
 550                                             cifs_sb->local_nls,
 551                                             cifs_remap(cifs_sb));
 552         else {
 553                 server = tcon->ses->server;
 554                 if (!server->ops->create_hardlink) {
 555                         rc = -ENOSYS;
 556                         goto cifs_hl_exit;
 557                 }
 558                 rc = server->ops->create_hardlink(xid, tcon, from_name, to_name,
 559                                                   cifs_sb);
 560                 if ((rc == -EIO) || (rc == -EINVAL))
 561                         rc = -EOPNOTSUPP;
 562         }
 563
 564         d_drop(direntry);       /* force new lookup from server of target */
 565
 566         /*
 567          * if source file is cached (oplocked) revalidate will not go to server
 568          * until the file is closed or oplock broken so update nlinks locally
 569          */
 570         if (d_really_is_positive(old_file)) {
 571                 cifsInode = CIFS_I(d_inode(old_file));
 572                 if (rc == 0) {
 573                         spin_lock(&d_inode(old_file)->i_lock);
 574                         inc_nlink(d_inode(old_file));
 575                         spin_unlock(&d_inode(old_file)->i_lock);
 576
 577                         /*
 578                          * parent dir timestamps will update from srv within a
 579                          * second, would it really be worth it to set the parent
 580                          * dir cifs inode time to zero to force revalidate
 581                          * (faster) for it too?
 582                          */
 583                 }
 584                 /*
 585                  * if not oplocked will force revalidate to get info on source
 586                  * file from srv.  Note Samba server prior to 4.2 has bug -
 587                  * not updating src file ctime on hardlinks but Windows servers
 588                  * handle it properly
 589                  */
 590                 cifsInode->time = 0;
 591
 592                 /*
 593                  * Will update parent dir timestamps from srv within a second.
 594                  * Would it really be worth it to set the parent dir (cifs
 595                  * inode) time field to zero to force revalidate on parent
 596                  * directory faster ie
 597                  *
 598                  * CIFS_I(inode)->time = 0;
 599                  */
 600         }
 601
 602 cifs_hl_exit:
 603         kfree(from_name);
 604         kfree(to_name);
 605         free_xid(xid);
 606         cifs_put_tlink(tlink);
 607         return rc;
 608 }
 609
 610 const char *
 611 cifs_get_link(struct dentry *direntry, struct inode *inode,
 612               struct delayed_call *done)
 613 {
 614         int rc = -ENOMEM;
 615         unsigned int xid;
 616         char *full_path = NULL;
 617         char *target_path = NULL;
 618         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 619         struct tcon_link *tlink = NULL;
 620         struct cifs_tcon *tcon;
 621         struct TCP_Server_Info *server;
 622
 623         if (!direntry)
 624                 return ERR_PTR(-ECHILD);
 625
 626         xid = get_xid();
 627
 628         tlink = cifs_sb_tlink(cifs_sb);
 629         if (IS_ERR(tlink)) {
 630                 free_xid(xid);
 631                 return ERR_CAST(tlink);
 632         }
 633         tcon = tlink_tcon(tlink);
 634         server = tcon->ses->server;
 635
 636         full_path = build_path_from_dentry(direntry);
 637         if (!full_path) {
 638                 free_xid(xid);
 639                 cifs_put_tlink(tlink);
 640                 return ERR_PTR(-ENOMEM);
 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                 rc = server->ops->query_symlink(xid, tcon, full_path,
 656                                                 &target_path, cifs_sb);
 657
 658         kfree(full_path);
 659         free_xid(xid);
 660         cifs_put_tlink(tlink);
 661         if (rc != 0) {
 662                 kfree(target_path);
 663                 return ERR_PTR(rc);
 664         }
 665         set_delayed_call(done, kfree_link, target_path);
 666         return target_path;
 667 }
 668
 669 int
 670 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 671 {
 672         int rc = -EOPNOTSUPP;
 673         unsigned int xid;
 674         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 675         struct tcon_link *tlink;
 676         struct cifs_tcon *pTcon;
 677         char *full_path = NULL;
 678         struct inode *newinode = NULL;
 679
 680         xid = get_xid();
 681
 682         tlink = cifs_sb_tlink(cifs_sb);
 683         if (IS_ERR(tlink)) {
 684                 rc = PTR_ERR(tlink);
 685                 goto symlink_exit;
 686         }
 687         pTcon = tlink_tcon(tlink);
 688
 689         full_path = build_path_from_dentry(direntry);
 690         if (full_path == NULL) {
 691                 rc = -ENOMEM;
 692                 goto symlink_exit;
 693         }
 694
 695         cifs_dbg(FYI, "Full path: %s\n", full_path);
 696         cifs_dbg(FYI, "symname is %s\n", symname);
 697
 698         /* BB what if DFS and this volume is on different share? BB */
 699         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
 700                 rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
 701         else if (pTcon->unix_ext)
 702                 rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
 703                                            cifs_sb->local_nls,
 704                                            cifs_remap(cifs_sb));
 705         /* else
 706            rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
 707                                         cifs_sb_target->local_nls); */
 708
 709         if (rc == 0) {
 710                 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 }