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 (sfrench@us.ibm.com)
   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
  26 static void
  27 renew_parental_timestamps(struct dentry *direntry)
  28 {
  29         /* BB check if there is a way to get the kernel to do this or if we
  30            really need this */
  31         do {
  32                 cifs_set_time(direntry, jiffies);
  33                 direntry = direntry->d_parent;
  34         } while (!IS_ROOT(direntry));
  35 }
  36
  37 char *
  38 cifs_build_path_to_root(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
  39                         struct cifs_tcon *tcon, int add_treename)
  40 {
  41         int pplen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
  42         int dfsplen;
  43         char *full_path = NULL;
  44
  45         /* if no prefix path, simply set path to the root of share to "" */
  46         if (pplen == 0) {
  47                 full_path = kzalloc(1, GFP_KERNEL);
  48                 return full_path;
  49         }
  50
  51         if (add_treename)
  52                 dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
  53         else
  54                 dfsplen = 0;
  55
  56         full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
  57         if (full_path == NULL)
  58                 return full_path;
  59
  60         if (dfsplen)
  61                 memcpy(full_path, tcon->treeName, dfsplen);
  62         full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
  63         memcpy(full_path + dfsplen + 1, ctx->prepath, pplen);
  64         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
  65         return full_path;
  66 }
  67
  68 /* Note: caller must free return buffer */
  69 const char *
  70 build_path_from_dentry(struct dentry *direntry, void *page)
  71 {
  72         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  73         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
  74         bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
  75
  76         return build_path_from_dentry_optional_prefix(direntry, page,
  77                                                       prefix);
  78 }
  79
  80 char *
  81 build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
  82                                        bool prefix)
  83 {
  84         int dfsplen;
  85         int pplen = 0;
  86         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  87         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_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(tcon->treeName, MAX_TREE_SIZE + 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, tcon->treeName, 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 /*
 138  * Don't allow path components longer than the server max.
 139  * Don't allow the separator character in a path component.
 140  * The VFS will not allow "/", but "\" is allowed by posix.
 141  */
 142 static int
 143 check_name(struct dentry *direntry, struct cifs_tcon *tcon)
 144 {
 145         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 146         int i;
 147
 148         if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
 149                      direntry->d_name.len >
 150                      le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
 151                 return -ENAMETOOLONG;
 152
 153         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
 154                 for (i = 0; i < direntry->d_name.len; i++) {
 155                         if (direntry->d_name.name[i] == '\\') {
 156                                 cifs_dbg(FYI, "Invalid file name\n");
 157                                 return -EINVAL;
 158                         }
 159                 }
 160         }
 161         return 0;
 162 }
 163
 164
 165 /* Inode operations in similar order to how they appear in Linux file fs.h */
 166
 167 static int
 168 cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
 169                struct tcon_link *tlink, unsigned oflags, umode_t mode,
 170                __u32 *oplock, struct cifs_fid *fid)
 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         FILE_ALL_INFO *buf = NULL;
 180         struct inode *newinode = NULL;
 181         int disposition;
 182         struct TCP_Server_Info *server = tcon->ses->server;
 183         struct cifs_open_parms oparms;
 184
 185         *oplock = 0;
 186         if (tcon->ses->server->oplocks)
 187                 *oplock = REQ_OPLOCK;
 188
 189         full_path = build_path_from_dentry(direntry, page);
 190         if (IS_ERR(full_path)) {
 191                 free_dentry_path(page);
 192                 return PTR_ERR(full_path);
 193         }
 194
 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
 264         desired_access = 0;
 265         if (OPEN_FMODE(oflags) & FMODE_READ)
 266                 desired_access |= GENERIC_READ; /* is this too little? */
 267         if (OPEN_FMODE(oflags) & FMODE_WRITE)
 268                 desired_access |= GENERIC_WRITE;
 269
 270         disposition = FILE_OVERWRITE_IF;
 271         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 272                 disposition = FILE_CREATE;
 273         else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 274                 disposition = FILE_OVERWRITE_IF;
 275         else if ((oflags & O_CREAT) == O_CREAT)
 276                 disposition = FILE_OPEN_IF;
 277         else
 278                 cifs_dbg(FYI, "Create flag not set in create function\n");
 279
 280         /*
 281          * BB add processing to set equivalent of mode - e.g. via CreateX with
 282          * ACLs
 283          */
 284
 285         if (!server->ops->open) {
 286                 rc = -ENOSYS;
 287                 goto out;
 288         }
 289
 290         buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
 291         if (buf == NULL) {
 292                 rc = -ENOMEM;
 293                 goto out;
 294         }
 295
 296         /*
 297          * if we're not using unix extensions, see if we need to set
 298          * ATTR_READONLY on the create call
 299          */
 300         if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
 301                 create_options |= CREATE_OPTION_READONLY;
 302
 303         oparms.tcon = tcon;
 304         oparms.cifs_sb = cifs_sb;
 305         oparms.desired_access = desired_access;
 306         oparms.create_options = cifs_create_options(cifs_sb, create_options);
 307         oparms.disposition = disposition;
 308         oparms.path = full_path;
 309         oparms.fid = fid;
 310         oparms.reconnect = false;
 311         oparms.mode = mode;
 312         rc = server->ops->open(xid, &oparms, oplock, buf);
 313         if (rc) {
 314                 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
 315                 goto out;
 316         }
 317
 318         /*
 319          * If Open reported that we actually created a file then we now have to
 320          * set the mode if possible.
 321          */
 322         if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
 323                 struct cifs_unix_set_info_args args = {
 324                                 .mode   = mode,
 325                                 .ctime  = NO_CHANGE_64,
 326                                 .atime  = NO_CHANGE_64,
 327                                 .mtime  = NO_CHANGE_64,
 328                                 .device = 0,
 329                 };
 330
 331                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 332                         args.uid = current_fsuid();
 333                         if (inode->i_mode & S_ISGID)
 334                                 args.gid = inode->i_gid;
 335                         else
 336                                 args.gid = current_fsgid();
 337                 } else {
 338                         args.uid = INVALID_UID; /* no change */
 339                         args.gid = INVALID_GID; /* no change */
 340                 }
 341                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
 342                                        current->tgid);
 343         } else {
 344                 /*
 345                  * BB implement mode setting via Windows security
 346                  * descriptors e.g.
 347                  */
 348                 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
 349
 350                 /* Could set r/o dos attribute if mode & 0222 == 0 */
 351         }
 352
 353 cifs_create_get_file_info:
 354         /* server might mask mode so we have to query for it */
 355         if (tcon->unix_ext)
 356                 rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
 357                                               xid);
 358         else {
 359                 /* TODO: Add support for calling POSIX query info here, but passing in fid */
 360                 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,
 361                                          xid, fid);
 362                 if (newinode) {
 363                         if (server->ops->set_lease_key)
 364                                 server->ops->set_lease_key(newinode, fid);
 365                         if ((*oplock & CIFS_CREATE_ACTION) && S_ISREG(newinode->i_mode)) {
 366                                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
 367                                         newinode->i_mode = mode;
 368                                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 369                                         newinode->i_uid = current_fsuid();
 370                                         if (inode->i_mode & S_ISGID)
 371                                                 newinode->i_gid = inode->i_gid;
 372                                         else
 373                                                 newinode->i_gid = current_fsgid();
 374                                 }
 375                         }
 376                 }
 377         }
 378
 379 cifs_create_set_dentry:
 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         kfree(buf);
 397         free_dentry_path(page);
 398         return rc;
 399
 400 out_err:
 401         if (server->ops->close)
 402                 server->ops->close(xid, tcon, fid);
 403         if (newinode)
 404                 iput(newinode);
 405         goto out;
 406 }
 407
 408 int
 409 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
 410                  struct file *file, unsigned oflags, umode_t mode)
 411 {
 412         int rc;
 413         unsigned int xid;
 414         struct tcon_link *tlink;
 415         struct cifs_tcon *tcon;
 416         struct TCP_Server_Info *server;
 417         struct cifs_fid fid;
 418         struct cifs_pending_open open;
 419         __u32 oplock;
 420         struct cifsFileInfo *file_info;
 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);
 479
 480         if (rc) {
 481                 cifs_del_pending_open(&open);
 482                 goto out;
 483         }
 484
 485         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 486                 file->f_mode |= FMODE_CREATED;
 487
 488         rc = finish_open(file, direntry, generic_file_open);
 489         if (rc) {
 490                 if (server->ops->close)
 491                         server->ops->close(xid, tcon, &fid);
 492                 cifs_del_pending_open(&open);
 493                 goto out;
 494         }
 495
 496         if (file->f_flags & O_DIRECT &&
 497             CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
 498                 if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 499                         file->f_op = &cifs_file_direct_nobrl_ops;
 500                 else
 501                         file->f_op = &cifs_file_direct_ops;
 502                 }
 503
 504         file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
 505         if (file_info == NULL) {
 506                 if (server->ops->close)
 507                         server->ops->close(xid, tcon, &fid);
 508                 cifs_del_pending_open(&open);
 509                 rc = -ENOMEM;
 510         }
 511
 512 out:
 513         cifs_put_tlink(tlink);
 514 out_free_xid:
 515         free_xid(xid);
 516         return rc;
 517 }
 518
 519 int cifs_create(struct user_namespace *mnt_userns, struct inode *inode,
 520                 struct dentry *direntry, umode_t mode, bool excl)
 521 {
 522         int rc;
 523         unsigned int xid = get_xid();
 524         /*
 525          * BB below access is probably too much for mknod to request
 526          *    but we have to do query and setpathinfo so requesting
 527          *    less could fail (unless we want to request getatr and setatr
 528          *    permissions (only).  At least for POSIX we do not have to
 529          *    request so much.
 530          */
 531         unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
 532         struct tcon_link *tlink;
 533         struct cifs_tcon *tcon;
 534         struct TCP_Server_Info *server;
 535         struct cifs_fid fid;
 536         __u32 oplock;
 537
 538         cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 539                  inode, direntry, direntry);
 540
 541         if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
 542                 return -EIO;
 543
 544         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
 545         rc = PTR_ERR(tlink);
 546         if (IS_ERR(tlink))
 547                 goto out_free_xid;
 548
 549         tcon = tlink_tcon(tlink);
 550         server = tcon->ses->server;
 551
 552         if (server->ops->new_lease_key)
 553                 server->ops->new_lease_key(&fid);
 554
 555         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
 556                             &oplock, &fid);
 557         if (!rc && server->ops->close)
 558                 server->ops->close(xid, tcon, &fid);
 559
 560         cifs_put_tlink(tlink);
 561 out_free_xid:
 562         free_xid(xid);
 563         return rc;
 564 }
 565
 566 int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
 567                struct dentry *direntry, umode_t mode, dev_t device_number)
 568 {
 569         int rc = -EPERM;
 570         unsigned int xid;
 571         struct cifs_sb_info *cifs_sb;
 572         struct tcon_link *tlink;
 573         struct cifs_tcon *tcon;
 574         const char *full_path;
 575         void *page;
 576
 577         if (!old_valid_dev(device_number))
 578                 return -EINVAL;
 579
 580         cifs_sb = CIFS_SB(inode->i_sb);
 581         if (unlikely(cifs_forced_shutdown(cifs_sb)))
 582                 return -EIO;
 583
 584         tlink = cifs_sb_tlink(cifs_sb);
 585         if (IS_ERR(tlink))
 586                 return PTR_ERR(tlink);
 587
 588         page = alloc_dentry_path();
 589         tcon = tlink_tcon(tlink);
 590         xid = get_xid();
 591
 592         full_path = build_path_from_dentry(direntry, page);
 593         if (IS_ERR(full_path)) {
 594                 rc = PTR_ERR(full_path);
 595                 goto mknod_out;
 596         }
 597
 598         rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
 599                                                full_path, mode,
 600                                                device_number);
 601
 602 mknod_out:
 603         free_dentry_path(page);
 604         free_xid(xid);
 605         cifs_put_tlink(tlink);
 606         return rc;
 607 }
 608
 609 struct dentry *
 610 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 611             unsigned int flags)
 612 {
 613         unsigned int xid;
 614         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 615         struct cifs_sb_info *cifs_sb;
 616         struct tcon_link *tlink;
 617         struct cifs_tcon *pTcon;
 618         struct inode *newInode = NULL;
 619         const char *full_path;
 620         void *page;
 621         int retry_count = 0;
 622
 623         xid = get_xid();
 624
 625         cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 626                  parent_dir_inode, direntry, direntry);
 627
 628         /* check whether path exists */
 629
 630         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 631         tlink = cifs_sb_tlink(cifs_sb);
 632         if (IS_ERR(tlink)) {
 633                 free_xid(xid);
 634                 return ERR_CAST(tlink);
 635         }
 636         pTcon = tlink_tcon(tlink);
 637
 638         rc = check_name(direntry, pTcon);
 639         if (unlikely(rc)) {
 640                 cifs_put_tlink(tlink);
 641                 free_xid(xid);
 642                 return ERR_PTR(rc);
 643         }
 644
 645         /* can not grab the rename sem here since it would
 646         deadlock in the cases (beginning of sys_rename itself)
 647         in which we already have the sb rename sem */
 648         page = alloc_dentry_path();
 649         full_path = build_path_from_dentry(direntry, page);
 650         if (IS_ERR(full_path)) {
 651                 cifs_put_tlink(tlink);
 652                 free_xid(xid);
 653                 free_dentry_path(page);
 654                 return ERR_CAST(full_path);
 655         }
 656
 657         if (d_really_is_positive(direntry)) {
 658                 cifs_dbg(FYI, "non-NULL inode in lookup\n");
 659         } else {
 660                 cifs_dbg(FYI, "NULL inode in lookup\n");
 661         }
 662         cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
 663                  full_path, d_inode(direntry));
 664
 665 again:
 666         if (pTcon->posix_extensions)
 667                 rc = smb311_posix_get_inode_info(&newInode, full_path, parent_dir_inode->i_sb, xid);
 668         else if (pTcon->unix_ext) {
 669                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 670                                               parent_dir_inode->i_sb, xid);
 671         } else {
 672                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 673                                 parent_dir_inode->i_sb, xid, NULL);
 674         }
 675
 676         if (rc == 0) {
 677                 /* since paths are not looked up by component - the parent
 678                    directories are presumed to be good here */
 679                 renew_parental_timestamps(direntry);
 680         } else if (rc == -EAGAIN && retry_count++ < 10) {
 681                 goto again;
 682         } else if (rc == -ENOENT) {
 683                 cifs_set_time(direntry, jiffies);
 684                 newInode = NULL;
 685         } else {
 686                 if (rc != -EACCES) {
 687                         cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
 688                         /* We special case check for Access Denied - since that
 689                         is a common return code */
 690                 }
 691                 newInode = ERR_PTR(rc);
 692         }
 693         free_dentry_path(page);
 694         cifs_put_tlink(tlink);
 695         free_xid(xid);
 696         return d_splice_alias(newInode, direntry);
 697 }
 698
 699 static int
 700 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
 701 {
 702         struct inode *inode;
 703         int rc;
 704
 705         if (flags & LOOKUP_RCU)
 706                 return -ECHILD;
 707
 708         if (d_really_is_positive(direntry)) {
 709                 inode = d_inode(direntry);
 710                 if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
 711                         CIFS_I(inode)->time = 0; /* force reval */
 712
 713                 rc = cifs_revalidate_dentry(direntry);
 714                 if (rc) {
 715                         cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
 716                         switch (rc) {
 717                         case -ENOENT:
 718                         case -ESTALE:
 719                                 /*
 720                                  * Those errors mean the dentry is invalid
 721                                  * (file was deleted or recreated)
 722                                  */
 723                                 return 0;
 724                         default:
 725                                 /*
 726                                  * Otherwise some unexpected error happened
 727                                  * report it as-is to VFS layer
 728                                  */
 729                                 return rc;
 730                         }
 731                 }
 732                 else {
 733                         /*
 734                          * If the inode wasn't known to be a dfs entry when
 735                          * the dentry was instantiated, such as when created
 736                          * via ->readdir(), it needs to be set now since the
 737                          * attributes will have been updated by
 738                          * cifs_revalidate_dentry().
 739                          */
 740                         if (IS_AUTOMOUNT(inode) &&
 741                            !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
 742                                 spin_lock(&direntry->d_lock);
 743                                 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 744                                 spin_unlock(&direntry->d_lock);
 745                         }
 746
 747                         return 1;
 748                 }
 749         }
 750
 751         /*
 752          * This may be nfsd (or something), anyway, we can't see the
 753          * intent of this. So, since this can be for creation, drop it.
 754          */
 755         if (!flags)
 756                 return 0;
 757
 758         /*
 759          * Drop the negative dentry, in order to make sure to use the
 760          * case sensitive name which is specified by user if this is
 761          * for creation.
 762          */
 763         if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
 764                 return 0;
 765
 766         if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
 767                 return 0;
 768
 769         return 1;
 770 }
 771
 772 /* static int cifs_d_delete(struct dentry *direntry)
 773 {
 774         int rc = 0;
 775
 776         cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
 777
 778         return rc;
 779 }     */
 780
 781 const struct dentry_operations cifs_dentry_ops = {
 782         .d_revalidate = cifs_d_revalidate,
 783         .d_automount = cifs_dfs_d_automount,
 784 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 785 };
 786
 787 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
 788 {
 789         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 790         unsigned long hash;
 791         wchar_t c;
 792         int i, charlen;
 793
 794         hash = init_name_hash(dentry);
 795         for (i = 0; i < q->len; i += charlen) {
 796                 charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
 797                 /* error out if we can't convert the character */
 798                 if (unlikely(charlen < 0))
 799                         return charlen;
 800                 hash = partial_name_hash(cifs_toupper(c), hash);
 801         }
 802         q->hash = end_name_hash(hash);
 803
 804         return 0;
 805 }
 806
 807 static int cifs_ci_compare(const struct dentry *dentry,
 808                 unsigned int len, const char *str, const struct qstr *name)
 809 {
 810         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 811         wchar_t c1, c2;
 812         int i, l1, l2;
 813
 814         /*
 815          * We make the assumption here that uppercase characters in the local
 816          * codepage are always the same length as their lowercase counterparts.
 817          *
 818          * If that's ever not the case, then this will fail to match it.
 819          */
 820         if (name->len != len)
 821                 return 1;
 822
 823         for (i = 0; i < len; i += l1) {
 824                 /* Convert characters in both strings to UTF-16. */
 825                 l1 = codepage->char2uni(&str[i], len - i, &c1);
 826                 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
 827
 828                 /*
 829                  * If we can't convert either character, just declare it to
 830                  * be 1 byte long and compare the original byte.
 831                  */
 832                 if (unlikely(l1 < 0 && l2 < 0)) {
 833                         if (str[i] != name->name[i])
 834                                 return 1;
 835                         l1 = 1;
 836                         continue;
 837                 }
 838
 839                 /*
 840                  * Here, we again ass|u|me that upper/lowercase versions of
 841                  * a character are the same length in the local NLS.
 842                  */
 843                 if (l1 != l2)
 844                         return 1;
 845
 846                 /* Now compare uppercase versions of these characters */
 847                 if (cifs_toupper(c1) != cifs_toupper(c2))
 848                         return 1;
 849         }
 850
 851         return 0;
 852 }
 853
 854 const struct dentry_operations cifs_ci_dentry_ops = {
 855         .d_revalidate = cifs_d_revalidate,
 856         .d_hash = cifs_ci_hash,
 857         .d_compare = cifs_ci_compare,
 858         .d_automount = cifs_dfs_d_automount,
 859 };