fs/cifs/dir.c

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