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