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 *__build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
  82                                                const char *tree, int tree_len,
  83                                                bool prefix)
  84 {
  85         int dfsplen;
  86         int pplen = 0;
  87         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  88         char dirsep = CIFS_DIR_SEP(cifs_sb);
  89         char *s;
  90
  91         if (unlikely(!page))
  92                 return ERR_PTR(-ENOMEM);
  93
  94         if (prefix)
  95                 dfsplen = strnlen(tree, tree_len + 1);
  96         else
  97                 dfsplen = 0;
  98
  99         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
 100                 pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
 101
 102         s = dentry_path_raw(direntry, page, PATH_MAX);
 103         if (IS_ERR(s))
 104                 return s;
 105         if (!s[1])      // for root we want "", not "/"
 106                 s++;
 107         if (s < (char *)page + pplen + dfsplen)
 108                 return ERR_PTR(-ENAMETOOLONG);
 109         if (pplen) {
 110                 cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
 111                 s -= pplen;
 112                 memcpy(s + 1, cifs_sb->prepath, pplen - 1);
 113                 *s = '/';
 114         }
 115         if (dirsep != '/') {
 116                 /* BB test paths to Windows with '/' in the midst of prepath */
 117                 char *p;
 118
 119                 for (p = s; *p; p++)
 120                         if (*p == '/')
 121                                 *p = dirsep;
 122         }
 123         if (dfsplen) {
 124                 s -= dfsplen;
 125                 memcpy(s, tree, dfsplen);
 126                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
 127                         int i;
 128                         for (i = 0; i < dfsplen; i++) {
 129                                 if (s[i] == '\\')
 130                                         s[i] = '/';
 131                         }
 132                 }
 133         }
 134         return s;
 135 }
 136
 137 char *build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
 138                                              bool prefix)
 139 {
 140         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 141         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 142
 143         return __build_path_from_dentry_optional_prefix(direntry, page, tcon->tree_name,
 144                                                         MAX_TREE_SIZE, prefix);
 145 }
 146
 147 /*
 148  * Don't allow path components longer than the server max.
 149  * Don't allow the separator character in a path component.
 150  * The VFS will not allow "/", but "\" is allowed by posix.
 151  */
 152 static int
 153 check_name(struct dentry *direntry, struct cifs_tcon *tcon)
 154 {
 155         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 156         int i;
 157
 158         if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
 159                      direntry->d_name.len >
 160                      le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
 161                 return -ENAMETOOLONG;
 162
 163         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
 164                 for (i = 0; i < direntry->d_name.len; i++) {
 165                         if (direntry->d_name.name[i] == '\\') {
 166                                 cifs_dbg(FYI, "Invalid file name\n");
 167                                 return -EINVAL;
 168                         }
 169                 }
 170         }
 171         return 0;
 172 }
 173
 174
 175 /* Inode operations in similar order to how they appear in Linux file fs.h */
 176
 177 static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
 178                           struct tcon_link *tlink, unsigned int oflags, umode_t mode, __u32 *oplock,
 179                           struct cifs_fid *fid, struct cifs_open_info_data *buf)
 180 {
 181         int rc = -ENOENT;
 182         int create_options = CREATE_NOT_DIR;
 183         int desired_access;
 184         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 185         struct cifs_tcon *tcon = tlink_tcon(tlink);
 186         const char *full_path;
 187         void *page = alloc_dentry_path();
 188         struct inode *newinode = NULL;
 189         int disposition;
 190         struct TCP_Server_Info *server = tcon->ses->server;
 191         struct cifs_open_parms oparms;
 192
 193         *oplock = 0;
 194         if (tcon->ses->server->oplocks)
 195                 *oplock = REQ_OPLOCK;
 196
 197         full_path = build_path_from_dentry(direntry, page);
 198         if (IS_ERR(full_path)) {
 199                 free_dentry_path(page);
 200                 return PTR_ERR(full_path);
 201         }
 202
 203 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 204         if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
 205             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 206                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 207                 rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
 208                                      oflags, oplock, &fid->netfid, xid);
 209                 switch (rc) {
 210                 case 0:
 211                         if (newinode == NULL) {
 212                                 /* query inode info */
 213                                 goto cifs_create_get_file_info;
 214                         }
 215
 216                         if (S_ISDIR(newinode->i_mode)) {
 217                                 CIFSSMBClose(xid, tcon, fid->netfid);
 218                                 iput(newinode);
 219                                 rc = -EISDIR;
 220                                 goto out;
 221                         }
 222
 223                         if (!S_ISREG(newinode->i_mode)) {
 224                                 /*
 225                                  * The server may allow us to open things like
 226                                  * FIFOs, but the client isn't set up to deal
 227                                  * with that. If it's not a regular file, just
 228                                  * close it and proceed as if it were a normal
 229                                  * lookup.
 230                                  */
 231                                 CIFSSMBClose(xid, tcon, fid->netfid);
 232                                 goto cifs_create_get_file_info;
 233                         }
 234                         /* success, no need to query */
 235                         goto cifs_create_set_dentry;
 236
 237                 case -ENOENT:
 238                         goto cifs_create_get_file_info;
 239
 240                 case -EIO:
 241                 case -EINVAL:
 242                         /*
 243                          * EIO could indicate that (posix open) operation is not
 244                          * supported, despite what server claimed in capability
 245                          * negotiation.
 246                          *
 247                          * POSIX open in samba versions 3.3.1 and earlier could
 248                          * incorrectly fail with invalid parameter.
 249                          */
 250                         tcon->broken_posix_open = true;
 251                         break;
 252
 253                 case -EREMOTE:
 254                 case -EOPNOTSUPP:
 255                         /*
 256                          * EREMOTE indicates DFS junction, which is not handled
 257                          * in posix open.  If either that or op not supported
 258                          * returned, follow the normal lookup.
 259                          */
 260                         break;
 261
 262                 default:
 263                         goto out;
 264                 }
 265                 /*
 266                  * fallthrough to retry, using older open call, this is case
 267                  * where server does not support this SMB level, and falsely
 268                  * claims capability (also get here for DFS case which should be
 269                  * rare for path not covered on files)
 270                  */
 271         }
 272 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 273
 274         desired_access = 0;
 275         if (OPEN_FMODE(oflags) & FMODE_READ)
 276                 desired_access |= GENERIC_READ; /* is this too little? */
 277         if (OPEN_FMODE(oflags) & FMODE_WRITE)
 278                 desired_access |= GENERIC_WRITE;
 279
 280         disposition = FILE_OVERWRITE_IF;
 281         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 282                 disposition = FILE_CREATE;
 283         else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 284                 disposition = FILE_OVERWRITE_IF;
 285         else if ((oflags & O_CREAT) == O_CREAT)
 286                 disposition = FILE_OPEN_IF;
 287         else
 288                 cifs_dbg(FYI, "Create flag not set in create function\n");
 289
 290         /*
 291          * BB add processing to set equivalent of mode - e.g. via CreateX with
 292          * ACLs
 293          */
 294
 295         if (!server->ops->open) {
 296                 rc = -ENOSYS;
 297                 goto out;
 298         }
 299
 300         /*
 301          * if we're not using unix extensions, see if we need to set
 302          * ATTR_READONLY on the create call
 303          */
 304         if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
 305                 create_options |= CREATE_OPTION_READONLY;
 306
 307         oparms.tcon = tcon;
 308         oparms.cifs_sb = cifs_sb;
 309         oparms.desired_access = desired_access;
 310         oparms.create_options = cifs_create_options(cifs_sb, create_options);
 311         oparms.disposition = disposition;
 312         oparms.path = full_path;
 313         oparms.fid = fid;
 314         oparms.reconnect = false;
 315         oparms.mode = mode;
 316         rc = server->ops->open(xid, &oparms, oplock, buf);
 317         if (rc) {
 318                 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
 319                 goto out;
 320         }
 321
 322 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 323         /*
 324          * If Open reported that we actually created a file then we now have to
 325          * set the mode if possible.
 326          */
 327         if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
 328                 struct cifs_unix_set_info_args args = {
 329                                 .mode   = mode,
 330                                 .ctime  = NO_CHANGE_64,
 331                                 .atime  = NO_CHANGE_64,
 332                                 .mtime  = NO_CHANGE_64,
 333                                 .device = 0,
 334                 };
 335
 336                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 337                         args.uid = current_fsuid();
 338                         if (inode->i_mode & S_ISGID)
 339                                 args.gid = inode->i_gid;
 340                         else
 341                                 args.gid = current_fsgid();
 342                 } else {
 343                         args.uid = INVALID_UID; /* no change */
 344                         args.gid = INVALID_GID; /* no change */
 345                 }
 346                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
 347                                        current->tgid);
 348         } else {
 349                 /*
 350                  * BB implement mode setting via Windows security
 351                  * descriptors e.g.
 352                  */
 353                 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
 354
 355                 /* Could set r/o dos attribute if mode & 0222 == 0 */
 356         }
 357
 358 cifs_create_get_file_info:
 359         /* server might mask mode so we have to query for it */
 360         if (tcon->unix_ext)
 361                 rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
 362                                               xid);
 363         else {
 364 #else
 365         {
 366 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 367                 /* TODO: Add support for calling POSIX query info here, but passing in fid */
 368                 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb, 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         free_dentry_path(page);
 406         return rc;
 407
 408 out_err:
 409         if (server->ops->close)
 410                 server->ops->close(xid, tcon, fid);
 411         if (newinode)
 412                 iput(newinode);
 413         goto out;
 414 }
 415
 416 int
 417 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
 418                  struct file *file, unsigned oflags, umode_t mode)
 419 {
 420         int rc;
 421         unsigned int xid;
 422         struct tcon_link *tlink;
 423         struct cifs_tcon *tcon;
 424         struct TCP_Server_Info *server;
 425         struct cifs_fid fid = {};
 426         struct cifs_pending_open open;
 427         __u32 oplock;
 428         struct cifsFileInfo *file_info;
 429         struct cifs_open_info_data buf = {};
 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, &buf);
 488         if (rc) {
 489                 cifs_del_pending_open(&open);
 490                 goto out;
 491         }
 492
 493         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 494                 file->f_mode |= FMODE_CREATED;
 495
 496         rc = finish_open(file, direntry, generic_file_open);
 497         if (rc) {
 498                 if (server->ops->close)
 499                         server->ops->close(xid, tcon, &fid);
 500                 cifs_del_pending_open(&open);
 501                 goto out;
 502         }
 503
 504         if (file->f_flags & O_DIRECT &&
 505             CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
 506                 if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 507                         file->f_op = &cifs_file_direct_nobrl_ops;
 508                 else
 509                         file->f_op = &cifs_file_direct_ops;
 510                 }
 511
 512         file_info = cifs_new_fileinfo(&fid, file, tlink, oplock, buf.symlink_target);
 513         if (file_info == NULL) {
 514                 if (server->ops->close)
 515                         server->ops->close(xid, tcon, &fid);
 516                 cifs_del_pending_open(&open);
 517                 rc = -ENOMEM;
 518                 goto out;
 519         }
 520
 521         fscache_use_cookie(cifs_inode_cookie(file_inode(file)),
 522                            file->f_mode & FMODE_WRITE);
 523
 524 out:
 525         cifs_put_tlink(tlink);
 526 out_free_xid:
 527         free_xid(xid);
 528         cifs_free_open_info(&buf);
 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         struct cifs_open_info_data buf = {};
 551
 552         cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 553                  inode, direntry, direntry);
 554
 555         if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb)))) {
 556                 rc = -EIO;
 557                 goto out_free_xid;
 558         }
 559
 560         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
 561         rc = PTR_ERR(tlink);
 562         if (IS_ERR(tlink))
 563                 goto out_free_xid;
 564
 565         tcon = tlink_tcon(tlink);
 566         server = tcon->ses->server;
 567
 568         if (server->ops->new_lease_key)
 569                 server->ops->new_lease_key(&fid);
 570
 571         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, &oplock, &fid, &buf);
 572         if (!rc && server->ops->close)
 573                 server->ops->close(xid, tcon, &fid);
 574
 575         cifs_free_open_info(&buf);
 576         cifs_put_tlink(tlink);
 577 out_free_xid:
 578         free_xid(xid);
 579         return rc;
 580 }
 581
 582 int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
 583                struct dentry *direntry, umode_t mode, dev_t device_number)
 584 {
 585         int rc = -EPERM;
 586         unsigned int xid;
 587         struct cifs_sb_info *cifs_sb;
 588         struct tcon_link *tlink;
 589         struct cifs_tcon *tcon;
 590         const char *full_path;
 591         void *page;
 592
 593         if (!old_valid_dev(device_number))
 594                 return -EINVAL;
 595
 596         cifs_sb = CIFS_SB(inode->i_sb);
 597         if (unlikely(cifs_forced_shutdown(cifs_sb)))
 598                 return -EIO;
 599
 600         tlink = cifs_sb_tlink(cifs_sb);
 601         if (IS_ERR(tlink))
 602                 return PTR_ERR(tlink);
 603
 604         page = alloc_dentry_path();
 605         tcon = tlink_tcon(tlink);
 606         xid = get_xid();
 607
 608         full_path = build_path_from_dentry(direntry, page);
 609         if (IS_ERR(full_path)) {
 610                 rc = PTR_ERR(full_path);
 611                 goto mknod_out;
 612         }
 613
 614         rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
 615                                                full_path, mode,
 616                                                device_number);
 617
 618 mknod_out:
 619         free_dentry_path(page);
 620         free_xid(xid);
 621         cifs_put_tlink(tlink);
 622         return rc;
 623 }
 624
 625 struct dentry *
 626 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 627             unsigned int flags)
 628 {
 629         unsigned int xid;
 630         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 631         struct cifs_sb_info *cifs_sb;
 632         struct tcon_link *tlink;
 633         struct cifs_tcon *pTcon;
 634         struct inode *newInode = NULL;
 635         const char *full_path;
 636         void *page;
 637         int retry_count = 0;
 638
 639         xid = get_xid();
 640
 641         cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 642                  parent_dir_inode, direntry, direntry);
 643
 644         /* check whether path exists */
 645
 646         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 647         tlink = cifs_sb_tlink(cifs_sb);
 648         if (IS_ERR(tlink)) {
 649                 free_xid(xid);
 650                 return ERR_CAST(tlink);
 651         }
 652         pTcon = tlink_tcon(tlink);
 653
 654         rc = check_name(direntry, pTcon);
 655         if (unlikely(rc)) {
 656                 cifs_put_tlink(tlink);
 657                 free_xid(xid);
 658                 return ERR_PTR(rc);
 659         }
 660
 661         /* can not grab the rename sem here since it would
 662         deadlock in the cases (beginning of sys_rename itself)
 663         in which we already have the sb rename sem */
 664         page = alloc_dentry_path();
 665         full_path = build_path_from_dentry(direntry, page);
 666         if (IS_ERR(full_path)) {
 667                 cifs_put_tlink(tlink);
 668                 free_xid(xid);
 669                 free_dentry_path(page);
 670                 return ERR_CAST(full_path);
 671         }
 672
 673         if (d_really_is_positive(direntry)) {
 674                 cifs_dbg(FYI, "non-NULL inode in lookup\n");
 675         } else {
 676                 cifs_dbg(FYI, "NULL inode in lookup\n");
 677         }
 678         cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
 679                  full_path, d_inode(direntry));
 680
 681 again:
 682         if (pTcon->posix_extensions)
 683                 rc = smb311_posix_get_inode_info(&newInode, full_path, parent_dir_inode->i_sb, xid);
 684         else if (pTcon->unix_ext) {
 685                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 686                                               parent_dir_inode->i_sb, xid);
 687         } else {
 688                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 689                                 parent_dir_inode->i_sb, xid, NULL);
 690         }
 691
 692         if (rc == 0) {
 693                 /* since paths are not looked up by component - the parent
 694                    directories are presumed to be good here */
 695                 renew_parental_timestamps(direntry);
 696         } else if (rc == -EAGAIN && retry_count++ < 10) {
 697                 goto again;
 698         } else if (rc == -ENOENT) {
 699                 cifs_set_time(direntry, jiffies);
 700                 newInode = NULL;
 701         } else {
 702                 if (rc != -EACCES) {
 703                         cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
 704                         /* We special case check for Access Denied - since that
 705                         is a common return code */
 706                 }
 707                 newInode = ERR_PTR(rc);
 708         }
 709         free_dentry_path(page);
 710         cifs_put_tlink(tlink);
 711         free_xid(xid);
 712         return d_splice_alias(newInode, direntry);
 713 }
 714
 715 static int
 716 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
 717 {
 718         struct inode *inode;
 719         int rc;
 720
 721         if (flags & LOOKUP_RCU)
 722                 return -ECHILD;
 723
 724         if (d_really_is_positive(direntry)) {
 725                 inode = d_inode(direntry);
 726                 if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
 727                         CIFS_I(inode)->time = 0; /* force reval */
 728
 729                 rc = cifs_revalidate_dentry(direntry);
 730                 if (rc) {
 731                         cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
 732                         switch (rc) {
 733                         case -ENOENT:
 734                         case -ESTALE:
 735                                 /*
 736                                  * Those errors mean the dentry is invalid
 737                                  * (file was deleted or recreated)
 738                                  */
 739                                 return 0;
 740                         default:
 741                                 /*
 742                                  * Otherwise some unexpected error happened
 743                                  * report it as-is to VFS layer
 744                                  */
 745                                 return rc;
 746                         }
 747                 }
 748                 else {
 749                         /*
 750                          * If the inode wasn't known to be a dfs entry when
 751                          * the dentry was instantiated, such as when created
 752                          * via ->readdir(), it needs to be set now since the
 753                          * attributes will have been updated by
 754                          * cifs_revalidate_dentry().
 755                          */
 756                         if (IS_AUTOMOUNT(inode) &&
 757                            !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
 758                                 spin_lock(&direntry->d_lock);
 759                                 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 760                                 spin_unlock(&direntry->d_lock);
 761                         }
 762
 763                         return 1;
 764                 }
 765         }
 766
 767         /*
 768          * This may be nfsd (or something), anyway, we can't see the
 769          * intent of this. So, since this can be for creation, drop it.
 770          */
 771         if (!flags)
 772                 return 0;
 773
 774         /*
 775          * Drop the negative dentry, in order to make sure to use the
 776          * case sensitive name which is specified by user if this is
 777          * for creation.
 778          */
 779         if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
 780                 return 0;
 781
 782         if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
 783                 return 0;
 784
 785         return 1;
 786 }
 787
 788 /* static int cifs_d_delete(struct dentry *direntry)
 789 {
 790         int rc = 0;
 791
 792         cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
 793
 794         return rc;
 795 }     */
 796
 797 const struct dentry_operations cifs_dentry_ops = {
 798         .d_revalidate = cifs_d_revalidate,
 799         .d_automount = cifs_dfs_d_automount,
 800 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 801 };
 802
 803 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
 804 {
 805         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 806         unsigned long hash;
 807         wchar_t c;
 808         int i, charlen;
 809
 810         hash = init_name_hash(dentry);
 811         for (i = 0; i < q->len; i += charlen) {
 812                 charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
 813                 /* error out if we can't convert the character */
 814                 if (unlikely(charlen < 0))
 815                         return charlen;
 816                 hash = partial_name_hash(cifs_toupper(c), hash);
 817         }
 818         q->hash = end_name_hash(hash);
 819
 820         return 0;
 821 }
 822
 823 static int cifs_ci_compare(const struct dentry *dentry,
 824                 unsigned int len, const char *str, const struct qstr *name)
 825 {
 826         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 827         wchar_t c1, c2;
 828         int i, l1, l2;
 829
 830         /*
 831          * We make the assumption here that uppercase characters in the local
 832          * codepage are always the same length as their lowercase counterparts.
 833          *
 834          * If that's ever not the case, then this will fail to match it.
 835          */
 836         if (name->len != len)
 837                 return 1;
 838
 839         for (i = 0; i < len; i += l1) {
 840                 /* Convert characters in both strings to UTF-16. */
 841                 l1 = codepage->char2uni(&str[i], len - i, &c1);
 842                 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
 843
 844                 /*
 845                  * If we can't convert either character, just declare it to
 846                  * be 1 byte long and compare the original byte.
 847                  */
 848                 if (unlikely(l1 < 0 && l2 < 0)) {
 849                         if (str[i] != name->name[i])
 850                                 return 1;
 851                         l1 = 1;
 852                         continue;
 853                 }
 854
 855                 /*
 856                  * Here, we again ass|u|me that upper/lowercase versions of
 857                  * a character are the same length in the local NLS.
 858                  */
 859                 if (l1 != l2)
 860                         return 1;
 861
 862                 /* Now compare uppercase versions of these characters */
 863                 if (cifs_toupper(c1) != cifs_toupper(c2))
 864                         return 1;
 865         }
 866
 867         return 0;
 868 }
 869
 870 const struct dentry_operations cifs_ci_dentry_ops = {
 871         .d_revalidate = cifs_d_revalidate,
 872         .d_hash = cifs_ci_hash,
 873         .d_compare = cifs_ci_compare,
 874         .d_automount = cifs_dfs_d_automount,
 875 };