fs/cifs/dir.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   vfs operations that deal with dentries
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2002,2009
   7  *   Author(s): Steve French ([email protected])
   8  *
   9  */
  10 #include <linux/fs.h>
  11 #include <linux/stat.h>
  12 #include <linux/slab.h>
  13 #include <linux/namei.h>
  14 #include <linux/mount.h>
  15 #include <linux/file.h>
  16 #include "cifsfs.h"
  17 #include "cifspdu.h"
  18 #include "cifsglob.h"
  19 #include "cifsproto.h"
  20 #include "cifs_debug.h"
  21 #include "cifs_fs_sb.h"
  22 #include "cifs_unicode.h"
  23 #include "fs_context.h"
  24 #include "cifs_ioctl.h"
  25 #include "fscache.h"
  26
  27 static void
  28 renew_parental_timestamps(struct dentry *direntry)
  29 {
  30         /* BB check if there is a way to get the kernel to do this or if we
  31            really need this */
  32         do {
  33                 cifs_set_time(direntry, jiffies);
  34                 direntry = direntry->d_parent;
  35         } while (!IS_ROOT(direntry));
  36 }
  37
  38 char *
  39 cifs_build_path_to_root(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
  40                         struct cifs_tcon *tcon, int add_treename)
  41 {
  42         int pplen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
  43         int dfsplen;
  44         char *full_path = NULL;
  45
  46         /* if no prefix path, simply set path to the root of share to "" */
  47         if (pplen == 0) {
  48                 full_path = kzalloc(1, GFP_KERNEL);
  49                 return full_path;
  50         }
  51
  52         if (add_treename)
  53                 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
  54         else
  55                 dfsplen = 0;
  56
  57         full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
  58         if (full_path == NULL)
  59                 return full_path;
  60
  61         if (dfsplen)
  62                 memcpy(full_path, tcon->treeName, dfsplen);
  63         full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
  64         memcpy(full_path + dfsplen + 1, ctx->prepath, pplen);
  65         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
  66         return full_path;
  67 }
  68
  69 /* Note: caller must free return buffer */
  70 const char *
  71 build_path_from_dentry(struct dentry *direntry, void *page)
  72 {
  73         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  74         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
  75         bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
  76
  77         return build_path_from_dentry_optional_prefix(direntry, page,
  78                                                       prefix);
  79 }
  80
  81 char *
  82 build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
  83                                        bool prefix)
  84 {
  85         int dfsplen;
  86         int pplen = 0;
  87         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  88         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
  89         char dirsep = CIFS_DIR_SEP(cifs_sb);
  90         char *s;
  91
  92         if (unlikely(!page))
  93                 return ERR_PTR(-ENOMEM);
  94
  95         if (prefix)
  96                 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
  97         else
  98                 dfsplen = 0;
  99
 100         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
 101                 pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
 102
 103         s = dentry_path_raw(direntry, page, PATH_MAX);
 104         if (IS_ERR(s))
 105                 return s;
 106         if (!s[1])      // for root we want "", not "/"
 107                 s++;
 108         if (s < (char *)page + pplen + dfsplen)
 109                 return ERR_PTR(-ENAMETOOLONG);
 110         if (pplen) {
 111                 cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
 112                 s -= pplen;
 113                 memcpy(s + 1, cifs_sb->prepath, pplen - 1);
 114                 *s = '/';
 115         }
 116         if (dirsep != '/') {
 117                 /* BB test paths to Windows with '/' in the midst of prepath */
 118                 char *p;
 119
 120                 for (p = s; *p; p++)
 121                         if (*p == '/')
 122                                 *p = dirsep;
 123         }
 124         if (dfsplen) {
 125                 s -= dfsplen;
 126                 memcpy(s, tcon->treeName, dfsplen);
 127                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
 128                         int i;
 129                         for (i = 0; i < dfsplen; i++) {
 130                                 if (s[i] == '\\')
 131                                         s[i] = '/';
 132                         }
 133                 }
 134         }
 135         return s;
 136 }
 137
 138 /*
 139  * Don't allow path components longer than the server max.
 140  * Don't allow the separator character in a path component.
 141  * The VFS will not allow "/", but "\" is allowed by posix.
 142  */
 143 static int
 144 check_name(struct dentry *direntry, struct cifs_tcon *tcon)
 145 {
 146         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 147         int i;
 148
 149         if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
 150                      direntry->d_name.len >
 151                      le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
 152                 return -ENAMETOOLONG;
 153
 154         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
 155                 for (i = 0; i < direntry->d_name.len; i++) {
 156                         if (direntry->d_name.name[i] == '\\') {
 157                                 cifs_dbg(FYI, "Invalid file name\n");
 158                                 return -EINVAL;
 159                         }
 160                 }
 161         }
 162         return 0;
 163 }
 164
 165
 166 /* Inode operations in similar order to how they appear in Linux file fs.h */
 167
 168 static int
 169 cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
 170                struct tcon_link *tlink, unsigned oflags, umode_t mode,
 171                __u32 *oplock, struct cifs_fid *fid)
 172 {
 173         int rc = -ENOENT;
 174         int create_options = CREATE_NOT_DIR;
 175         int desired_access;
 176         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 177         struct cifs_tcon *tcon = tlink_tcon(tlink);
 178         const char *full_path;
 179         void *page = alloc_dentry_path();
 180         FILE_ALL_INFO *buf = NULL;
 181         struct inode *newinode = NULL;
 182         int disposition;
 183         struct TCP_Server_Info *server = tcon->ses->server;
 184         struct cifs_open_parms oparms;
 185
 186         *oplock = 0;
 187         if (tcon->ses->server->oplocks)
 188                 *oplock = REQ_OPLOCK;
 189
 190         full_path = build_path_from_dentry(direntry, page);
 191         if (IS_ERR(full_path)) {
 192                 free_dentry_path(page);
 193                 return PTR_ERR(full_path);
 194         }
 195
 196 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 197         if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
 198             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 199                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 200                 rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
 201                                      oflags, oplock, &fid->netfid, xid);
 202                 switch (rc) {
 203                 case 0:
 204                         if (newinode == NULL) {
 205                                 /* query inode info */
 206                                 goto cifs_create_get_file_info;
 207                         }
 208
 209                         if (S_ISDIR(newinode->i_mode)) {
 210                                 CIFSSMBClose(xid, tcon, fid->netfid);
 211                                 iput(newinode);
 212                                 rc = -EISDIR;
 213                                 goto out;
 214                         }
 215
 216                         if (!S_ISREG(newinode->i_mode)) {
 217                                 /*
 218                                  * The server may allow us to open things like
 219                                  * FIFOs, but the client isn't set up to deal
 220                                  * with that. If it's not a regular file, just
 221                                  * close it and proceed as if it were a normal
 222                                  * lookup.
 223                                  */
 224                                 CIFSSMBClose(xid, tcon, fid->netfid);
 225                                 goto cifs_create_get_file_info;
 226                         }
 227                         /* success, no need to query */
 228                         goto cifs_create_set_dentry;
 229
 230                 case -ENOENT:
 231                         goto cifs_create_get_file_info;
 232
 233                 case -EIO:
 234                 case -EINVAL:
 235                         /*
 236                          * EIO could indicate that (posix open) operation is not
 237                          * supported, despite what server claimed in capability
 238                          * negotiation.
 239                          *
 240                          * POSIX open in samba versions 3.3.1 and earlier could
 241                          * incorrectly fail with invalid parameter.
 242                          */
 243                         tcon->broken_posix_open = true;
 244                         break;
 245
 246                 case -EREMOTE:
 247                 case -EOPNOTSUPP:
 248                         /*
 249                          * EREMOTE indicates DFS junction, which is not handled
 250                          * in posix open.  If either that or op not supported
 251                          * returned, follow the normal lookup.
 252                          */
 253                         break;
 254
 255                 default:
 256                         goto out;
 257                 }
 258                 /*
 259                  * fallthrough to retry, using older open call, this is case
 260                  * where server does not support this SMB level, and falsely
 261                  * claims capability (also get here for DFS case which should be
 262                  * rare for path not covered on files)
 263                  */
 264         }
 265 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 266
 267         desired_access = 0;
 268         if (OPEN_FMODE(oflags) & FMODE_READ)
 269                 desired_access |= GENERIC_READ; /* is this too little? */
 270         if (OPEN_FMODE(oflags) & FMODE_WRITE)
 271                 desired_access |= GENERIC_WRITE;
 272
 273         disposition = FILE_OVERWRITE_IF;
 274         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 275                 disposition = FILE_CREATE;
 276         else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 277                 disposition = FILE_OVERWRITE_IF;
 278         else if ((oflags & O_CREAT) == O_CREAT)
 279                 disposition = FILE_OPEN_IF;
 280         else
 281                 cifs_dbg(FYI, "Create flag not set in create function\n");
 282
 283         /*
 284          * BB add processing to set equivalent of mode - e.g. via CreateX with
 285          * ACLs
 286          */
 287
 288         if (!server->ops->open) {
 289                 rc = -ENOSYS;
 290                 goto out;
 291         }
 292
 293         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 294         if (buf == NULL) {
 295                 rc = -ENOMEM;
 296                 goto out;
 297         }
 298
 299         /*
 300          * if we're not using unix extensions, see if we need to set
 301          * ATTR_READONLY on the create call
 302          */
 303         if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
 304                 create_options |= CREATE_OPTION_READONLY;
 305
 306         oparms.tcon = tcon;
 307         oparms.cifs_sb = cifs_sb;
 308         oparms.desired_access = desired_access;
 309         oparms.create_options = cifs_create_options(cifs_sb, create_options);
 310         oparms.disposition = disposition;
 311         oparms.path = full_path;
 312         oparms.fid = fid;
 313         oparms.reconnect = false;
 314         oparms.mode = mode;
 315         rc = server->ops->open(xid, &oparms, oplock, buf);
 316         if (rc) {
 317                 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
 318                 goto out;
 319         }
 320
 321 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 322         /*
 323          * If Open reported that we actually created a file then we now have to
 324          * set the mode if possible.
 325          */
 326         if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
 327                 struct cifs_unix_set_info_args args = {
 328                                 .mode   = mode,
 329                                 .ctime  = NO_CHANGE_64,
 330                                 .atime  = NO_CHANGE_64,
 331                                 .mtime  = NO_CHANGE_64,
 332                                 .device = 0,
 333                 };
 334
 335                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 336                         args.uid = current_fsuid();
 337                         if (inode->i_mode & S_ISGID)
 338                                 args.gid = inode->i_gid;
 339                         else
 340                                 args.gid = current_fsgid();
 341                 } else {
 342                         args.uid = INVALID_UID; /* no change */
 343                         args.gid = INVALID_GID; /* no change */
 344                 }
 345                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
 346                                        current->tgid);
 347         } else {
 348                 /*
 349                  * BB implement mode setting via Windows security
 350                  * descriptors e.g.
 351                  */
 352                 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
 353
 354                 /* Could set r/o dos attribute if mode & 0222 == 0 */
 355         }
 356
 357 cifs_create_get_file_info:
 358         /* server might mask mode so we have to query for it */
 359         if (tcon->unix_ext)
 360                 rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
 361                                               xid);
 362         else {
 363 #else
 364         {
 365 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 366                 /* TODO: Add support for calling POSIX query info here, but passing in fid */
 367                 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
 368                                          xid, fid);
 369                 if (newinode) {
 370                         if (server->ops->set_lease_key)
 371                                 server->ops->set_lease_key(newinode, fid);
 372                         if ((*oplock & CIFS_CREATE_ACTION) && S_ISREG(newinode->i_mode)) {
 373                                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
 374                                         newinode->i_mode = mode;
 375                                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 376                                         newinode->i_uid = current_fsuid();
 377                                         if (inode->i_mode & S_ISGID)
 378                                                 newinode->i_gid = inode->i_gid;
 379                                         else
 380                                                 newinode->i_gid = current_fsgid();
 381                                 }
 382                         }
 383                 }
 384         }
 385
 386 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 387 cifs_create_set_dentry:
 388 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 389         if (rc != 0) {
 390                 cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
 391                          rc);
 392                 goto out_err;
 393         }
 394
 395         if (newinode)
 396                 if (S_ISDIR(newinode->i_mode)) {
 397                         rc = -EISDIR;
 398                         goto out_err;
 399                 }
 400
 401         d_drop(direntry);
 402         d_add(direntry, newinode);
 403
 404 out:
 405         kfree(buf);
 406         free_dentry_path(page);
 407         return rc;
 408
 409 out_err:
 410         if (server->ops->close)
 411                 server->ops->close(xid, tcon, fid);
 412         if (newinode)
 413                 iput(newinode);
 414         goto out;
 415 }
 416
 417 int
 418 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
 419                  struct file *file, unsigned oflags, umode_t mode)
 420 {
 421         int rc;
 422         unsigned int xid;
 423         struct tcon_link *tlink;
 424         struct cifs_tcon *tcon;
 425         struct TCP_Server_Info *server;
 426         struct cifs_fid fid;
 427         struct cifs_pending_open open;
 428         __u32 oplock;
 429         struct cifsFileInfo *file_info;
 430
 431         if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
 432                 return -EIO;
 433
 434         /*
 435          * Posix open is only called (at lookup time) for file create now. For
 436          * opens (rather than creates), because we do not know if it is a file
 437          * or directory yet, and current Samba no longer allows us to do posix
 438          * open on dirs, we could end up wasting an open call on what turns out
 439          * to be a dir. For file opens, we wait to call posix open till
 440          * cifs_open.  It could be added to atomic_open in the future but the
 441          * performance tradeoff of the extra network request when EISDIR or
 442          * EACCES is returned would have to be weighed against the 50% reduction
 443          * in network traffic in the other paths.
 444          */
 445         if (!(oflags & O_CREAT)) {
 446                 struct dentry *res;
 447
 448                 /*
 449                  * Check for hashed negative dentry. We have already revalidated
 450                  * the dentry and it is fine. No need to perform another lookup.
 451                  */
 452                 if (!d_in_lookup(direntry))
 453                         return -ENOENT;
 454
 455                 res = cifs_lookup(inode, direntry, 0);
 456                 if (IS_ERR(res))
 457                         return PTR_ERR(res);
 458
 459                 return finish_no_open(file, res);
 460         }
 461
 462         xid = get_xid();
 463
 464         cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 465                  inode, direntry, direntry);
 466
 467         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
 468         if (IS_ERR(tlink)) {
 469                 rc = PTR_ERR(tlink);
 470                 goto out_free_xid;
 471         }
 472
 473         tcon = tlink_tcon(tlink);
 474
 475         rc = check_name(direntry, tcon);
 476         if (rc)
 477                 goto out;
 478
 479         server = tcon->ses->server;
 480
 481         if (server->ops->new_lease_key)
 482                 server->ops->new_lease_key(&fid);
 483
 484         cifs_add_pending_open(&fid, tlink, &open);
 485
 486         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
 487                             &oplock, &fid);
 488
 489         if (rc) {
 490                 cifs_del_pending_open(&open);
 491                 goto out;
 492         }
 493
 494         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 495                 file->f_mode |= FMODE_CREATED;
 496
 497         rc = finish_open(file, direntry, generic_file_open);
 498         if (rc) {
 499                 if (server->ops->close)
 500                         server->ops->close(xid, tcon, &fid);
 501                 cifs_del_pending_open(&open);
 502                 goto out;
 503         }
 504
 505         if (file->f_flags & O_DIRECT &&
 506             CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
 507                 if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 508                         file->f_op = &cifs_file_direct_nobrl_ops;
 509                 else
 510                         file->f_op = &cifs_file_direct_ops;
 511                 }
 512
 513         file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
 514         if (file_info == NULL) {
 515                 if (server->ops->close)
 516                         server->ops->close(xid, tcon, &fid);
 517                 cifs_del_pending_open(&open);
 518                 rc = -ENOMEM;
 519                 goto out;
 520         }
 521
 522         fscache_use_cookie(cifs_inode_cookie(file_inode(file)),
 523                            file->f_mode & FMODE_WRITE);
 524
 525 out:
 526         cifs_put_tlink(tlink);
 527 out_free_xid:
 528         free_xid(xid);
 529         return rc;
 530 }
 531
 532 int cifs_create(struct user_namespace *mnt_userns, struct inode *inode,
 533                 struct dentry *direntry, umode_t mode, bool excl)
 534 {
 535         int rc;
 536         unsigned int xid = get_xid();
 537         /*
 538          * BB below access is probably too much for mknod to request
 539          *    but we have to do query and setpathinfo so requesting
 540          *    less could fail (unless we want to request getatr and setatr
 541          *    permissions (only).  At least for POSIX we do not have to
 542          *    request so much.
 543          */
 544         unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
 545         struct tcon_link *tlink;
 546         struct cifs_tcon *tcon;
 547         struct TCP_Server_Info *server;
 548         struct cifs_fid fid;
 549         __u32 oplock;
 550
 551         cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 552                  inode, direntry, direntry);
 553
 554         if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
 555                 return -EIO;
 556
 557         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
 558         rc = PTR_ERR(tlink);
 559         if (IS_ERR(tlink))
 560                 goto out_free_xid;
 561
 562         tcon = tlink_tcon(tlink);
 563         server = tcon->ses->server;
 564
 565         if (server->ops->new_lease_key)
 566                 server->ops->new_lease_key(&fid);
 567
 568         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
 569                             &oplock, &fid);
 570         if (!rc && server->ops->close)
 571                 server->ops->close(xid, tcon, &fid);
 572
 573         cifs_put_tlink(tlink);
 574 out_free_xid:
 575         free_xid(xid);
 576         return rc;
 577 }
 578
 579 int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
 580                struct dentry *direntry, umode_t mode, dev_t device_number)
 581 {
 582         int rc = -EPERM;
 583         unsigned int xid;
 584         struct cifs_sb_info *cifs_sb;
 585         struct tcon_link *tlink;
 586         struct cifs_tcon *tcon;
 587         const char *full_path;
 588         void *page;
 589
 590         if (!old_valid_dev(device_number))
 591                 return -EINVAL;
 592
 593         cifs_sb = CIFS_SB(inode->i_sb);
 594         if (unlikely(cifs_forced_shutdown(cifs_sb)))
 595                 return -EIO;
 596
 597         tlink = cifs_sb_tlink(cifs_sb);
 598         if (IS_ERR(tlink))
 599                 return PTR_ERR(tlink);
 600
 601         page = alloc_dentry_path();
 602         tcon = tlink_tcon(tlink);
 603         xid = get_xid();
 604
 605         full_path = build_path_from_dentry(direntry, page);
 606         if (IS_ERR(full_path)) {
 607                 rc = PTR_ERR(full_path);
 608                 goto mknod_out;
 609         }
 610
 611         rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
 612                                                full_path, mode,
 613                                                device_number);
 614
 615 mknod_out:
 616         free_dentry_path(page);
 617         free_xid(xid);
 618         cifs_put_tlink(tlink);
 619         return rc;
 620 }
 621
 622 struct dentry *
 623 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 624             unsigned int flags)
 625 {
 626         unsigned int xid;
 627         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 628         struct cifs_sb_info *cifs_sb;
 629         struct tcon_link *tlink;
 630         struct cifs_tcon *pTcon;
 631         struct inode *newInode = NULL;
 632         const char *full_path;
 633         void *page;
 634         int retry_count = 0;
 635
 636         xid = get_xid();
 637
 638         cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 639                  parent_dir_inode, direntry, direntry);
 640
 641         /* check whether path exists */
 642
 643         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 644         tlink = cifs_sb_tlink(cifs_sb);
 645         if (IS_ERR(tlink)) {
 646                 free_xid(xid);
 647                 return ERR_CAST(tlink);
 648         }
 649         pTcon = tlink_tcon(tlink);
 650
 651         rc = check_name(direntry, pTcon);
 652         if (unlikely(rc)) {
 653                 cifs_put_tlink(tlink);
 654                 free_xid(xid);
 655                 return ERR_PTR(rc);
 656         }
 657
 658         /* can not grab the rename sem here since it would
 659         deadlock in the cases (beginning of sys_rename itself)
 660         in which we already have the sb rename sem */
 661         page = alloc_dentry_path();
 662         full_path = build_path_from_dentry(direntry, page);
 663         if (IS_ERR(full_path)) {
 664                 cifs_put_tlink(tlink);
 665                 free_xid(xid);
 666                 free_dentry_path(page);
 667                 return ERR_CAST(full_path);
 668         }
 669
 670         if (d_really_is_positive(direntry)) {
 671                 cifs_dbg(FYI, "non-NULL inode in lookup\n");
 672         } else {
 673                 cifs_dbg(FYI, "NULL inode in lookup\n");
 674         }
 675         cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
 676                  full_path, d_inode(direntry));
 677
 678 again:
 679         if (pTcon->posix_extensions)
 680                 rc = smb311_posix_get_inode_info(&newInode, full_path, parent_dir_inode->i_sb, xid);
 681         else if (pTcon->unix_ext) {
 682                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 683                                               parent_dir_inode->i_sb, xid);
 684         } else {
 685                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 686                                 parent_dir_inode->i_sb, xid, NULL);
 687         }
 688
 689         if (rc == 0) {
 690                 /* since paths are not looked up by component - the parent
 691                    directories are presumed to be good here */
 692                 renew_parental_timestamps(direntry);
 693         } else if (rc == -EAGAIN && retry_count++ < 10) {
 694                 goto again;
 695         } else if (rc == -ENOENT) {
 696                 cifs_set_time(direntry, jiffies);
 697                 newInode = NULL;
 698         } else {
 699                 if (rc != -EACCES) {
 700                         cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
 701                         /* We special case check for Access Denied - since that
 702                         is a common return code */
 703                 }
 704                 newInode = ERR_PTR(rc);
 705         }
 706         free_dentry_path(page);
 707         cifs_put_tlink(tlink);
 708         free_xid(xid);
 709         return d_splice_alias(newInode, direntry);
 710 }
 711
 712 static int
 713 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
 714 {
 715         struct inode *inode;
 716         int rc;
 717
 718         if (flags & LOOKUP_RCU)
 719                 return -ECHILD;
 720
 721         if (d_really_is_positive(direntry)) {
 722                 inode = d_inode(direntry);
 723                 if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
 724                         CIFS_I(inode)->time = 0; /* force reval */
 725
 726                 rc = cifs_revalidate_dentry(direntry);
 727                 if (rc) {
 728                         cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
 729                         switch (rc) {
 730                         case -ENOENT:
 731                         case -ESTALE:
 732                                 /*
 733                                  * Those errors mean the dentry is invalid
 734                                  * (file was deleted or recreated)
 735                                  */
 736                                 return 0;
 737                         default:
 738                                 /*
 739                                  * Otherwise some unexpected error happened
 740                                  * report it as-is to VFS layer
 741                                  */
 742                                 return rc;
 743                         }
 744                 }
 745                 else {
 746                         /*
 747                          * If the inode wasn't known to be a dfs entry when
 748                          * the dentry was instantiated, such as when created
 749                          * via ->readdir(), it needs to be set now since the
 750                          * attributes will have been updated by
 751                          * cifs_revalidate_dentry().
 752                          */
 753                         if (IS_AUTOMOUNT(inode) &&
 754                            !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
 755                                 spin_lock(&direntry->d_lock);
 756                                 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 757                                 spin_unlock(&direntry->d_lock);
 758                         }
 759
 760                         return 1;
 761                 }
 762         }
 763
 764         /*
 765          * This may be nfsd (or something), anyway, we can't see the
 766          * intent of this. So, since this can be for creation, drop it.
 767          */
 768         if (!flags)
 769                 return 0;
 770
 771         /*
 772          * Drop the negative dentry, in order to make sure to use the
 773          * case sensitive name which is specified by user if this is
 774          * for creation.
 775          */
 776         if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
 777                 return 0;
 778
 779         if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
 780                 return 0;
 781
 782         return 1;
 783 }
 784
 785 /* static int cifs_d_delete(struct dentry *direntry)
 786 {
 787         int rc = 0;
 788
 789         cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
 790
 791         return rc;
 792 }     */
 793
 794 const struct dentry_operations cifs_dentry_ops = {
 795         .d_revalidate = cifs_d_revalidate,
 796         .d_automount = cifs_dfs_d_automount,
 797 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 798 };
 799
 800 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
 801 {
 802         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 803         unsigned long hash;
 804         wchar_t c;
 805         int i, charlen;
 806
 807         hash = init_name_hash(dentry);
 808         for (i = 0; i < q->len; i += charlen) {
 809                 charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
 810                 /* error out if we can't convert the character */
 811                 if (unlikely(charlen < 0))
 812                         return charlen;
 813                 hash = partial_name_hash(cifs_toupper(c), hash);
 814         }
 815         q->hash = end_name_hash(hash);
 816
 817         return 0;
 818 }
 819
 820 static int cifs_ci_compare(const struct dentry *dentry,
 821                 unsigned int len, const char *str, const struct qstr *name)
 822 {
 823         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 824         wchar_t c1, c2;
 825         int i, l1, l2;
 826
 827         /*
 828          * We make the assumption here that uppercase characters in the local
 829          * codepage are always the same length as their lowercase counterparts.
 830          *
 831          * If that's ever not the case, then this will fail to match it.
 832          */
 833         if (name->len != len)
 834                 return 1;
 835
 836         for (i = 0; i < len; i += l1) {
 837                 /* Convert characters in both strings to UTF-16. */
 838                 l1 = codepage->char2uni(&str[i], len - i, &c1);
 839                 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
 840
 841                 /*
 842                  * If we can't convert either character, just declare it to
 843                  * be 1 byte long and compare the original byte.
 844                  */
 845                 if (unlikely(l1 < 0 && l2 < 0)) {
 846                         if (str[i] != name->name[i])
 847                                 return 1;
 848                         l1 = 1;
 849                         continue;
 850                 }
 851
 852                 /*
 853                  * Here, we again ass|u|me that upper/lowercase versions of
 854                  * a character are the same length in the local NLS.
 855                  */
 856                 if (l1 != l2)
 857                         return 1;
 858
 859                 /* Now compare uppercase versions of these characters */
 860                 if (cifs_toupper(c1) != cifs_toupper(c2))
 861                         return 1;
 862         }
 863
 864         return 0;
 865 }
 866
 867 const struct dentry_operations cifs_ci_dentry_ops = {
 868         .d_revalidate = cifs_d_revalidate,
 869         .d_hash = cifs_ci_hash,
 870         .d_compare = cifs_ci_compare,
 871         .d_automount = cifs_dfs_d_automount,
 872 };