fs/cifs/dir.c

   1 /*
   2  *   fs/cifs/dir.c
   3  *
   4  *   vfs operations that deal with dentries
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2002,2009
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23 #include <linux/fs.h>
  24 #include <linux/stat.h>
  25 #include <linux/slab.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/file.h>
  29 #include "cifsfs.h"
  30 #include "cifspdu.h"
  31 #include "cifsglob.h"
  32 #include "cifsproto.h"
  33 #include "cifs_debug.h"
  34 #include "cifs_fs_sb.h"
  35
  36 static void
  37 renew_parental_timestamps(struct dentry *direntry)
  38 {
  39         /* BB check if there is a way to get the kernel to do this or if we
  40            really need this */
  41         do {
  42                 direntry->d_time = jiffies;
  43                 direntry = direntry->d_parent;
  44         } while (!IS_ROOT(direntry));
  45 }
  46
  47 /* Note: caller must free return buffer */
  48 char *
  49 build_path_from_dentry(struct dentry *direntry)
  50 {
  51         struct dentry *temp;
  52         int namelen;
  53         int dfsplen;
  54         char *full_path;
  55         char dirsep;
  56         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  57         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
  58         unsigned seq;
  59
  60         dirsep = CIFS_DIR_SEP(cifs_sb);
  61         if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
  62                 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
  63         else
  64                 dfsplen = 0;
  65 cifs_bp_rename_retry:
  66         namelen = dfsplen;
  67         seq = read_seqbegin(&rename_lock);
  68         rcu_read_lock();
  69         for (temp = direntry; !IS_ROOT(temp);) {
  70                 namelen += (1 + temp->d_name.len);
  71                 temp = temp->d_parent;
  72                 if (temp == NULL) {
  73                         cERROR(1, "corrupt dentry");
  74                         rcu_read_unlock();
  75                         return NULL;
  76                 }
  77         }
  78         rcu_read_unlock();
  79
  80         full_path = kmalloc(namelen+1, GFP_KERNEL);
  81         if (full_path == NULL)
  82                 return full_path;
  83         full_path[namelen] = 0; /* trailing null */
  84         rcu_read_lock();
  85         for (temp = direntry; !IS_ROOT(temp);) {
  86                 spin_lock(&temp->d_lock);
  87                 namelen -= 1 + temp->d_name.len;
  88                 if (namelen < 0) {
  89                         spin_unlock(&temp->d_lock);
  90                         break;
  91                 } else {
  92                         full_path[namelen] = dirsep;
  93                         strncpy(full_path + namelen + 1, temp->d_name.name,
  94                                 temp->d_name.len);
  95                         cFYI(0, "name: %s", full_path + namelen);
  96                 }
  97                 spin_unlock(&temp->d_lock);
  98                 temp = temp->d_parent;
  99                 if (temp == NULL) {
 100                         cERROR(1, "corrupt dentry");
 101                         rcu_read_unlock();
 102                         kfree(full_path);
 103                         return NULL;
 104                 }
 105         }
 106         rcu_read_unlock();
 107         if (namelen != dfsplen || read_seqretry(&rename_lock, seq)) {
 108                 cFYI(1, "did not end path lookup where expected. namelen=%d "
 109                         "dfsplen=%d", namelen, dfsplen);
 110                 /* presumably this is only possible if racing with a rename
 111                 of one of the parent directories  (we can not lock the dentries
 112                 above us to prevent this, but retrying should be harmless) */
 113                 kfree(full_path);
 114                 goto cifs_bp_rename_retry;
 115         }
 116         /* DIR_SEP already set for byte  0 / vs \ but not for
 117            subsequent slashes in prepath which currently must
 118            be entered the right way - not sure if there is an alternative
 119            since the '\' is a valid posix character so we can not switch
 120            those safely to '/' if any are found in the middle of the prepath */
 121         /* BB test paths to Windows with '/' in the midst of prepath */
 122
 123         if (dfsplen) {
 124                 strncpy(full_path, tcon->treeName, dfsplen);
 125                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
 126                         int i;
 127                         for (i = 0; i < dfsplen; i++) {
 128                                 if (full_path[i] == '\\')
 129                                         full_path[i] = '/';
 130                         }
 131                 }
 132         }
 133         return full_path;
 134 }
 135
 136 /*
 137  * Don't allow the separator character in a path component.
 138  * The VFS will not allow "/", but "\" is allowed by posix.
 139  */
 140 static int
 141 check_name(struct dentry *direntry)
 142 {
 143         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 144         int i;
 145
 146         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
 147                 for (i = 0; i < direntry->d_name.len; i++) {
 148                         if (direntry->d_name.name[i] == '\\') {
 149                                 cFYI(1, "Invalid file name");
 150                                 return -EINVAL;
 151                         }
 152                 }
 153         }
 154         return 0;
 155 }
 156
 157
 158 /* Inode operations in similar order to how they appear in Linux file fs.h */
 159
 160 static int
 161 cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
 162                struct tcon_link *tlink, unsigned oflags, umode_t mode,
 163                __u32 *oplock, __u16 *fileHandle, int *created)
 164 {
 165         int rc = -ENOENT;
 166         int create_options = CREATE_NOT_DIR;
 167         int desiredAccess;
 168         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 169         struct cifs_tcon *tcon = tlink_tcon(tlink);
 170         char *full_path = NULL;
 171         FILE_ALL_INFO *buf = NULL;
 172         struct inode *newinode = NULL;
 173         int disposition;
 174
 175         *oplock = 0;
 176         if (tcon->ses->server->oplocks)
 177                 *oplock = REQ_OPLOCK;
 178
 179         full_path = build_path_from_dentry(direntry);
 180         if (full_path == NULL) {
 181                 rc = -ENOMEM;
 182                 goto out;
 183         }
 184
 185         if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
 186             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 187                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 188                 rc = cifs_posix_open(full_path, &newinode,
 189                         inode->i_sb, mode, oflags, oplock, fileHandle, xid);
 190                 switch (rc) {
 191                 case 0:
 192                         if (newinode == NULL) {
 193                                 /* query inode info */
 194                                 goto cifs_create_get_file_info;
 195                         }
 196
 197                         if (!S_ISREG(newinode->i_mode)) {
 198                                 /*
 199                                  * The server may allow us to open things like
 200                                  * FIFOs, but the client isn't set up to deal
 201                                  * with that. If it's not a regular file, just
 202                                  * close it and proceed as if it were a normal
 203                                  * lookup.
 204                                  */
 205                                 CIFSSMBClose(xid, tcon, *fileHandle);
 206                                 goto cifs_create_get_file_info;
 207                         }
 208                         /* success, no need to query */
 209                         goto cifs_create_set_dentry;
 210
 211                 case -ENOENT:
 212                         goto cifs_create_get_file_info;
 213
 214                 case -EIO:
 215                 case -EINVAL:
 216                         /*
 217                          * EIO could indicate that (posix open) operation is not
 218                          * supported, despite what server claimed in capability
 219                          * negotiation.
 220                          *
 221                          * POSIX open in samba versions 3.3.1 and earlier could
 222                          * incorrectly fail with invalid parameter.
 223                          */
 224                         tcon->broken_posix_open = true;
 225                         break;
 226
 227                 case -EREMOTE:
 228                 case -EOPNOTSUPP:
 229                         /*
 230                          * EREMOTE indicates DFS junction, which is not handled
 231                          * in posix open.  If either that or op not supported
 232                          * returned, follow the normal lookup.
 233                          */
 234                         break;
 235
 236                 default:
 237                         goto out;
 238                 }
 239                 /*
 240                  * fallthrough to retry, using older open call, this is case
 241                  * where server does not support this SMB level, and falsely
 242                  * claims capability (also get here for DFS case which should be
 243                  * rare for path not covered on files)
 244                  */
 245         }
 246
 247         desiredAccess = 0;
 248         if (OPEN_FMODE(oflags) & FMODE_READ)
 249                 desiredAccess |= GENERIC_READ; /* is this too little? */
 250         if (OPEN_FMODE(oflags) & FMODE_WRITE)
 251                 desiredAccess |= GENERIC_WRITE;
 252
 253         disposition = FILE_OVERWRITE_IF;
 254         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 255                 disposition = FILE_CREATE;
 256         else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 257                 disposition = FILE_OVERWRITE_IF;
 258         else if ((oflags & O_CREAT) == O_CREAT)
 259                 disposition = FILE_OPEN_IF;
 260         else
 261                 cFYI(1, "Create flag not set in create function");
 262
 263         /* BB add processing to set equivalent of mode - e.g. via CreateX with
 264            ACLs */
 265
 266         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 267         if (buf == NULL) {
 268                 rc = -ENOMEM;
 269                 goto out;
 270         }
 271
 272         /*
 273          * if we're not using unix extensions, see if we need to set
 274          * ATTR_READONLY on the create call
 275          */
 276         if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
 277                 create_options |= CREATE_OPTION_READONLY;
 278
 279         if (backup_cred(cifs_sb))
 280                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 281
 282         if (tcon->ses->capabilities & CAP_NT_SMBS)
 283                 rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
 284                          desiredAccess, create_options,
 285                          fileHandle, oplock, buf, cifs_sb->local_nls,
 286                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 287         else
 288                 rc = -EIO; /* no NT SMB support fall into legacy open below */
 289
 290         if (rc == -EIO) {
 291                 /* old server, retry the open legacy style */
 292                 rc = SMBLegacyOpen(xid, tcon, full_path, disposition,
 293                         desiredAccess, create_options,
 294                         fileHandle, oplock, buf, cifs_sb->local_nls,
 295                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 296         }
 297         if (rc) {
 298                 cFYI(1, "cifs_create returned 0x%x", rc);
 299                 goto out;
 300         }
 301
 302         /* If Open reported that we actually created a file
 303            then we now have to set the mode if possible */
 304         if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
 305                 struct cifs_unix_set_info_args args = {
 306                                 .mode   = mode,
 307                                 .ctime  = NO_CHANGE_64,
 308                                 .atime  = NO_CHANGE_64,
 309                                 .mtime  = NO_CHANGE_64,
 310                                 .device = 0,
 311                 };
 312
 313                 *created |= FILE_CREATED;
 314                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 315                         args.uid = (__u64) current_fsuid();
 316                         if (inode->i_mode & S_ISGID)
 317                                 args.gid = (__u64) inode->i_gid;
 318                         else
 319                                 args.gid = (__u64) current_fsgid();
 320                 } else {
 321                         args.uid = NO_CHANGE_64;
 322                         args.gid = NO_CHANGE_64;
 323                 }
 324                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, *fileHandle,
 325                                         current->tgid);
 326         } else {
 327                 /* BB implement mode setting via Windows security
 328                    descriptors e.g. */
 329                 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
 330
 331                 /* Could set r/o dos attribute if mode & 0222 == 0 */
 332         }
 333
 334 cifs_create_get_file_info:
 335         /* server might mask mode so we have to query for it */
 336         if (tcon->unix_ext)
 337                 rc = cifs_get_inode_info_unix(&newinode, full_path,
 338                                               inode->i_sb, xid);
 339         else {
 340                 rc = cifs_get_inode_info(&newinode, full_path, buf,
 341                                          inode->i_sb, xid, fileHandle);
 342                 if (newinode) {
 343                         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
 344                                 newinode->i_mode = mode;
 345                         if ((*oplock & CIFS_CREATE_ACTION) &&
 346                             (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)) {
 347                                 newinode->i_uid = current_fsuid();
 348                                 if (inode->i_mode & S_ISGID)
 349                                         newinode->i_gid = inode->i_gid;
 350                                 else
 351                                         newinode->i_gid = current_fsgid();
 352                         }
 353                 }
 354         }
 355
 356 cifs_create_set_dentry:
 357         if (rc != 0) {
 358                 cFYI(1, "Create worked, get_inode_info failed rc = %d", rc);
 359                 CIFSSMBClose(xid, tcon, *fileHandle);
 360                 goto out;
 361         }
 362         d_drop(direntry);
 363         d_add(direntry, newinode);
 364
 365 out:
 366         kfree(buf);
 367         kfree(full_path);
 368         return rc;
 369 }
 370
 371 int
 372 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
 373                  struct file *file, unsigned oflags, umode_t mode,
 374                  int *opened)
 375 {
 376         int rc;
 377         unsigned int xid;
 378         struct tcon_link *tlink;
 379         struct cifs_tcon *tcon;
 380         __u16 fileHandle;
 381         __u32 oplock;
 382         struct cifsFileInfo *pfile_info;
 383
 384         /* Posix open is only called (at lookup time) for file create now.  For
 385          * opens (rather than creates), because we do not know if it is a file
 386          * or directory yet, and current Samba no longer allows us to do posix
 387          * open on dirs, we could end up wasting an open call on what turns out
 388          * to be a dir. For file opens, we wait to call posix open till
 389          * cifs_open.  It could be added to atomic_open in the future but the
 390          * performance tradeoff of the extra network request when EISDIR or
 391          * EACCES is returned would have to be weighed against the 50% reduction
 392          * in network traffic in the other paths.
 393          */
 394         if (!(oflags & O_CREAT)) {
 395                 struct dentry *res = cifs_lookup(inode, direntry, 0);
 396                 if (IS_ERR(res))
 397                         return PTR_ERR(res);
 398
 399                 return finish_no_open(file, res);
 400         }
 401
 402         rc = check_name(direntry);
 403         if (rc)
 404                 return rc;
 405
 406         xid = get_xid();
 407
 408         cFYI(1, "parent inode = 0x%p name is: %s and dentry = 0x%p",
 409              inode, direntry->d_name.name, direntry);
 410
 411         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
 412         if (IS_ERR(tlink))
 413                 goto out_free_xid;
 414
 415         tcon = tlink_tcon(tlink);
 416
 417         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
 418                             &oplock, &fileHandle, opened);
 419
 420         if (rc)
 421                 goto out;
 422
 423         rc = finish_open(file, direntry, generic_file_open, opened);
 424         if (rc) {
 425                 CIFSSMBClose(xid, tcon, fileHandle);
 426                 goto out;
 427         }
 428
 429         pfile_info = cifs_new_fileinfo(fileHandle, file, tlink, oplock);
 430         if (pfile_info == NULL) {
 431                 CIFSSMBClose(xid, tcon, fileHandle);
 432                 rc = -ENOMEM;
 433         }
 434
 435 out:
 436         cifs_put_tlink(tlink);
 437 out_free_xid:
 438         free_xid(xid);
 439         return rc;
 440 }
 441
 442 int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
 443                 bool excl)
 444 {
 445         int rc;
 446         unsigned int xid = get_xid();
 447         /*
 448          * BB below access is probably too much for mknod to request
 449          *    but we have to do query and setpathinfo so requesting
 450          *    less could fail (unless we want to request getatr and setatr
 451          *    permissions (only).  At least for POSIX we do not have to
 452          *    request so much.
 453          */
 454         unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
 455         struct tcon_link *tlink;
 456         __u16 fileHandle;
 457         __u32 oplock;
 458         int created = FILE_CREATED;
 459
 460         cFYI(1, "cifs_create parent inode = 0x%p name is: %s and dentry = 0x%p",
 461              inode, direntry->d_name.name, direntry);
 462
 463         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
 464         rc = PTR_ERR(tlink);
 465         if (IS_ERR(tlink))
 466                 goto out_free_xid;
 467
 468         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
 469                             &oplock, &fileHandle, &created);
 470         if (!rc)
 471                 CIFSSMBClose(xid, tlink_tcon(tlink), fileHandle);
 472
 473         cifs_put_tlink(tlink);
 474 out_free_xid:
 475         free_xid(xid);
 476         return rc;
 477 }
 478
 479 int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
 480                 dev_t device_number)
 481 {
 482         int rc = -EPERM;
 483         unsigned int xid;
 484         int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
 485         struct cifs_sb_info *cifs_sb;
 486         struct tcon_link *tlink;
 487         struct cifs_tcon *pTcon;
 488         struct cifs_io_parms io_parms;
 489         char *full_path = NULL;
 490         struct inode *newinode = NULL;
 491         int oplock = 0;
 492         u16 fileHandle;
 493         FILE_ALL_INFO *buf = NULL;
 494         unsigned int bytes_written;
 495         struct win_dev *pdev;
 496
 497         if (!old_valid_dev(device_number))
 498                 return -EINVAL;
 499
 500         cifs_sb = CIFS_SB(inode->i_sb);
 501         tlink = cifs_sb_tlink(cifs_sb);
 502         if (IS_ERR(tlink))
 503                 return PTR_ERR(tlink);
 504
 505         pTcon = tlink_tcon(tlink);
 506
 507         xid = get_xid();
 508
 509         full_path = build_path_from_dentry(direntry);
 510         if (full_path == NULL) {
 511                 rc = -ENOMEM;
 512                 goto mknod_out;
 513         }
 514
 515         if (pTcon->unix_ext) {
 516                 struct cifs_unix_set_info_args args = {
 517                         .mode   = mode & ~current_umask(),
 518                         .ctime  = NO_CHANGE_64,
 519                         .atime  = NO_CHANGE_64,
 520                         .mtime  = NO_CHANGE_64,
 521                         .device = device_number,
 522                 };
 523                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 524                         args.uid = (__u64) current_fsuid();
 525                         args.gid = (__u64) current_fsgid();
 526                 } else {
 527                         args.uid = NO_CHANGE_64;
 528                         args.gid = NO_CHANGE_64;
 529                 }
 530                 rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, &args,
 531                                             cifs_sb->local_nls,
 532                                             cifs_sb->mnt_cifs_flags &
 533                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 534                 if (rc)
 535                         goto mknod_out;
 536
 537                 rc = cifs_get_inode_info_unix(&newinode, full_path,
 538                                                 inode->i_sb, xid);
 539
 540                 if (rc == 0)
 541                         d_instantiate(direntry, newinode);
 542                 goto mknod_out;
 543         }
 544
 545         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
 546                 goto mknod_out;
 547
 548
 549         cFYI(1, "sfu compat create special file");
 550
 551         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 552         if (buf == NULL) {
 553                 kfree(full_path);
 554                 rc = -ENOMEM;
 555                 free_xid(xid);
 556                 return rc;
 557         }
 558
 559         if (backup_cred(cifs_sb))
 560                 create_options |= CREATE_OPEN_BACKUP_INTENT;
 561
 562         rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_CREATE,
 563                          GENERIC_WRITE, create_options,
 564                          &fileHandle, &oplock, buf, cifs_sb->local_nls,
 565                          cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 566         if (rc)
 567                 goto mknod_out;
 568
 569         /* BB Do not bother to decode buf since no local inode yet to put
 570          * timestamps in, but we can reuse it safely */
 571
 572         pdev = (struct win_dev *)buf;
 573         io_parms.netfid = fileHandle;
 574         io_parms.pid = current->tgid;
 575         io_parms.tcon = pTcon;
 576         io_parms.offset = 0;
 577         io_parms.length = sizeof(struct win_dev);
 578         if (S_ISCHR(mode)) {
 579                 memcpy(pdev->type, "IntxCHR", 8);
 580                 pdev->major =
 581                       cpu_to_le64(MAJOR(device_number));
 582                 pdev->minor =
 583                       cpu_to_le64(MINOR(device_number));
 584                 rc = CIFSSMBWrite(xid, &io_parms,
 585                         &bytes_written, (char *)pdev,
 586                         NULL, 0);
 587         } else if (S_ISBLK(mode)) {
 588                 memcpy(pdev->type, "IntxBLK", 8);
 589                 pdev->major =
 590                       cpu_to_le64(MAJOR(device_number));
 591                 pdev->minor =
 592                       cpu_to_le64(MINOR(device_number));
 593                 rc = CIFSSMBWrite(xid, &io_parms,
 594                         &bytes_written, (char *)pdev,
 595                         NULL, 0);
 596         } /* else if (S_ISFIFO) */
 597         CIFSSMBClose(xid, pTcon, fileHandle);
 598         d_drop(direntry);
 599
 600         /* FIXME: add code here to set EAs */
 601
 602 mknod_out:
 603         kfree(full_path);
 604         kfree(buf);
 605         free_xid(xid);
 606         cifs_put_tlink(tlink);
 607         return rc;
 608 }
 609
 610 struct dentry *
 611 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 612             unsigned int flags)
 613 {
 614         unsigned int xid;
 615         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 616         struct cifs_sb_info *cifs_sb;
 617         struct tcon_link *tlink;
 618         struct cifs_tcon *pTcon;
 619         struct inode *newInode = NULL;
 620         char *full_path = NULL;
 621
 622         xid = get_xid();
 623
 624         cFYI(1, "parent inode = 0x%p name is: %s and dentry = 0x%p",
 625               parent_dir_inode, direntry->d_name.name, direntry);
 626
 627         /* check whether path exists */
 628
 629         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 630         tlink = cifs_sb_tlink(cifs_sb);
 631         if (IS_ERR(tlink)) {
 632                 free_xid(xid);
 633                 return (struct dentry *)tlink;
 634         }
 635         pTcon = tlink_tcon(tlink);
 636
 637         rc = check_name(direntry);
 638         if (rc)
 639                 goto lookup_out;
 640
 641         /* can not grab the rename sem here since it would
 642         deadlock in the cases (beginning of sys_rename itself)
 643         in which we already have the sb rename sem */
 644         full_path = build_path_from_dentry(direntry);
 645         if (full_path == NULL) {
 646                 rc = -ENOMEM;
 647                 goto lookup_out;
 648         }
 649
 650         if (direntry->d_inode != NULL) {
 651                 cFYI(1, "non-NULL inode in lookup");
 652         } else {
 653                 cFYI(1, "NULL inode in lookup");
 654         }
 655         cFYI(1, "Full path: %s inode = 0x%p", full_path, direntry->d_inode);
 656
 657         if (pTcon->unix_ext) {
 658                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 659                                               parent_dir_inode->i_sb, xid);
 660         } else {
 661                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 662                                 parent_dir_inode->i_sb, xid, NULL);
 663         }
 664
 665         if ((rc == 0) && (newInode != NULL)) {
 666                 d_add(direntry, newInode);
 667                 /* since paths are not looked up by component - the parent
 668                    directories are presumed to be good here */
 669                 renew_parental_timestamps(direntry);
 670
 671         } else if (rc == -ENOENT) {
 672                 rc = 0;
 673                 direntry->d_time = jiffies;
 674                 d_add(direntry, NULL);
 675         /*      if it was once a directory (but how can we tell?) we could do
 676                 shrink_dcache_parent(direntry); */
 677         } else if (rc != -EACCES) {
 678                 cERROR(1, "Unexpected lookup error %d", rc);
 679                 /* We special case check for Access Denied - since that
 680                 is a common return code */
 681         }
 682
 683 lookup_out:
 684         kfree(full_path);
 685         cifs_put_tlink(tlink);
 686         free_xid(xid);
 687         return ERR_PTR(rc);
 688 }
 689
 690 static int
 691 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
 692 {
 693         if (flags & LOOKUP_RCU)
 694                 return -ECHILD;
 695
 696         if (direntry->d_inode) {
 697                 if (cifs_revalidate_dentry(direntry))
 698                         return 0;
 699                 else {
 700                         /*
 701                          * If the inode wasn't known to be a dfs entry when
 702                          * the dentry was instantiated, such as when created
 703                          * via ->readdir(), it needs to be set now since the
 704                          * attributes will have been updated by
 705                          * cifs_revalidate_dentry().
 706                          */
 707                         if (IS_AUTOMOUNT(direntry->d_inode) &&
 708                            !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
 709                                 spin_lock(&direntry->d_lock);
 710                                 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 711                                 spin_unlock(&direntry->d_lock);
 712                         }
 713
 714                         return 1;
 715                 }
 716         }
 717
 718         /*
 719          * This may be nfsd (or something), anyway, we can't see the
 720          * intent of this. So, since this can be for creation, drop it.
 721          */
 722         if (!flags)
 723                 return 0;
 724
 725         /*
 726          * Drop the negative dentry, in order to make sure to use the
 727          * case sensitive name which is specified by user if this is
 728          * for creation.
 729          */
 730         if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
 731                 return 0;
 732
 733         if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled)
 734                 return 0;
 735
 736         return 1;
 737 }
 738
 739 /* static int cifs_d_delete(struct dentry *direntry)
 740 {
 741         int rc = 0;
 742
 743         cFYI(1, "In cifs d_delete, name = %s", direntry->d_name.name);
 744
 745         return rc;
 746 }     */
 747
 748 const struct dentry_operations cifs_dentry_ops = {
 749         .d_revalidate = cifs_d_revalidate,
 750         .d_automount = cifs_dfs_d_automount,
 751 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 752 };
 753
 754 static int cifs_ci_hash(const struct dentry *dentry, const struct inode *inode,
 755                 struct qstr *q)
 756 {
 757         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 758         unsigned long hash;
 759         int i;
 760
 761         hash = init_name_hash();
 762         for (i = 0; i < q->len; i++)
 763                 hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
 764                                          hash);
 765         q->hash = end_name_hash(hash);
 766
 767         return 0;
 768 }
 769
 770 static int cifs_ci_compare(const struct dentry *parent,
 771                 const struct inode *pinode,
 772                 const struct dentry *dentry, const struct inode *inode,
 773                 unsigned int len, const char *str, const struct qstr *name)
 774 {
 775         struct nls_table *codepage = CIFS_SB(pinode->i_sb)->local_nls;
 776
 777         if ((name->len == len) &&
 778             (nls_strnicmp(codepage, name->name, str, len) == 0))
 779                 return 0;
 780         return 1;
 781 }
 782
 783 const struct dentry_operations cifs_ci_dentry_ops = {
 784         .d_revalidate = cifs_d_revalidate,
 785         .d_hash = cifs_ci_hash,
 786         .d_compare = cifs_ci_compare,
 787         .d_automount = cifs_dfs_d_automount,
 788 };