smb/client/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 #include "fscache.h"
  26
  27 static void
  28 renew_parental_timestamps(struct dentry *direntry)
  29 {
  30         /* BB check if there is a way to get the kernel to do this or if we
  31            really need this */
  32         do {
  33                 cifs_set_time(direntry, jiffies);
  34                 direntry = direntry->d_parent;
  35         } while (!IS_ROOT(direntry));
  36 }
  37
  38 char *
  39 cifs_build_path_to_root(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
  40                         struct cifs_tcon *tcon, int add_treename)
  41 {
  42         int pplen = ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
  43         int dfsplen;
  44         char *full_path = NULL;
  45
  46         /* if no prefix path, simply set path to the root of share to "" */
  47         if (pplen == 0) {
  48                 full_path = kzalloc(1, GFP_KERNEL);
  49                 return full_path;
  50         }
  51
  52         if (add_treename)
  53                 dfsplen = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1);
  54         else
  55                 dfsplen = 0;
  56
  57         full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
  58         if (full_path == NULL)
  59                 return full_path;
  60
  61         if (dfsplen)
  62                 memcpy(full_path, tcon->tree_name, dfsplen);
  63         full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
  64         memcpy(full_path + dfsplen + 1, ctx->prepath, pplen);
  65         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
  66         return full_path;
  67 }
  68
  69 /* Note: caller must free return buffer */
  70 const char *
  71 build_path_from_dentry(struct dentry *direntry, void *page)
  72 {
  73         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  74         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
  75         bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
  76
  77         return build_path_from_dentry_optional_prefix(direntry, page,
  78                                                       prefix);
  79 }
  80
  81 char *
  82 build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
  83                                        bool prefix)
  84 {
  85         int dfsplen;
  86         int pplen = 0;
  87         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
  88         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
  89         char dirsep = CIFS_DIR_SEP(cifs_sb);
  90         char *s;
  91
  92         if (unlikely(!page))
  93                 return ERR_PTR(-ENOMEM);
  94
  95         if (prefix)
  96                 dfsplen = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1);
  97         else
  98                 dfsplen = 0;
  99
 100         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
 101                 pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
 102
 103         s = dentry_path_raw(direntry, page, PATH_MAX);
 104         if (IS_ERR(s))
 105                 return s;
 106         if (!s[1])      // for root we want "", not "/"
 107                 s++;
 108         if (s < (char *)page + pplen + dfsplen)
 109                 return ERR_PTR(-ENAMETOOLONG);
 110         if (pplen) {
 111                 cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
 112                 s -= pplen;
 113                 memcpy(s + 1, cifs_sb->prepath, pplen - 1);
 114                 *s = '/';
 115         }
 116         if (dirsep != '/') {
 117                 /* BB test paths to Windows with '/' in the midst of prepath */
 118                 char *p;
 119
 120                 for (p = s; *p; p++)
 121                         if (*p == '/')
 122                                 *p = dirsep;
 123         }
 124         if (dfsplen) {
 125                 s -= dfsplen;
 126                 memcpy(s, tcon->tree_name, dfsplen);
 127                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
 128                         int i;
 129                         for (i = 0; i < dfsplen; i++) {
 130                                 if (s[i] == '\\')
 131                                         s[i] = '/';
 132                         }
 133                 }
 134         }
 135         return s;
 136 }
 137
 138 /*
 139  * Don't allow path components longer than the server max.
 140  * Don't allow the separator character in a path component.
 141  * The VFS will not allow "/", but "\" is allowed by posix.
 142  */
 143 static int
 144 check_name(struct dentry *direntry, struct cifs_tcon *tcon)
 145 {
 146         struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
 147         int i;
 148
 149         if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
 150                      direntry->d_name.len >
 151                      le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
 152                 return -ENAMETOOLONG;
 153
 154         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
 155                 for (i = 0; i < direntry->d_name.len; i++) {
 156                         if (direntry->d_name.name[i] == '\\') {
 157                                 cifs_dbg(FYI, "Invalid file name\n");
 158                                 return -EINVAL;
 159                         }
 160                 }
 161         }
 162         return 0;
 163 }
 164
 165
 166 /* Inode operations in similar order to how they appear in Linux file fs.h */
 167
 168 static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
 169                           struct tcon_link *tlink, unsigned int oflags, umode_t mode, __u32 *oplock,
 170                           struct cifs_fid *fid, struct cifs_open_info_data *buf)
 171 {
 172         int rc = -ENOENT;
 173         int create_options = CREATE_NOT_DIR;
 174         int desired_access;
 175         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 176         struct cifs_tcon *tcon = tlink_tcon(tlink);
 177         const char *full_path;
 178         void *page = alloc_dentry_path();
 179         struct inode *newinode = NULL;
 180         int disposition;
 181         struct TCP_Server_Info *server = tcon->ses->server;
 182         struct cifs_open_parms oparms;
 183         int rdwr_for_fscache = 0;
 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 we're caching, we need to be able to fill in around partial writes. */
 196         if (cifs_fscache_enabled(inode) && (oflags & O_ACCMODE) == O_WRONLY)
 197                 rdwr_for_fscache = 1;
 198
 199 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 200         if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
 201             (CIFS_UNIX_POSIX_PATH_OPS_CAP &
 202                         le64_to_cpu(tcon->fsUnixInfo.Capability))) {
 203                 rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode,
 204                                      oflags, oplock, &fid->netfid, xid);
 205                 switch (rc) {
 206                 case 0:
 207                         if (newinode == NULL) {
 208                                 /* query inode info */
 209                                 goto cifs_create_get_file_info;
 210                         }
 211
 212                         if (S_ISDIR(newinode->i_mode)) {
 213                                 CIFSSMBClose(xid, tcon, fid->netfid);
 214                                 iput(newinode);
 215                                 rc = -EISDIR;
 216                                 goto out;
 217                         }
 218
 219                         if (!S_ISREG(newinode->i_mode)) {
 220                                 /*
 221                                  * The server may allow us to open things like
 222                                  * FIFOs, but the client isn't set up to deal
 223                                  * with that. If it's not a regular file, just
 224                                  * close it and proceed as if it were a normal
 225                                  * lookup.
 226                                  */
 227                                 CIFSSMBClose(xid, tcon, fid->netfid);
 228                                 goto cifs_create_get_file_info;
 229                         }
 230                         /* success, no need to query */
 231                         goto cifs_create_set_dentry;
 232
 233                 case -ENOENT:
 234                         goto cifs_create_get_file_info;
 235
 236                 case -EIO:
 237                 case -EINVAL:
 238                         /*
 239                          * EIO could indicate that (posix open) operation is not
 240                          * supported, despite what server claimed in capability
 241                          * negotiation.
 242                          *
 243                          * POSIX open in samba versions 3.3.1 and earlier could
 244                          * incorrectly fail with invalid parameter.
 245                          */
 246                         tcon->broken_posix_open = true;
 247                         break;
 248
 249                 case -EREMOTE:
 250                 case -EOPNOTSUPP:
 251                         /*
 252                          * EREMOTE indicates DFS junction, which is not handled
 253                          * in posix open.  If either that or op not supported
 254                          * returned, follow the normal lookup.
 255                          */
 256                         break;
 257
 258                 default:
 259                         goto out;
 260                 }
 261                 /*
 262                  * fallthrough to retry, using older open call, this is case
 263                  * where server does not support this SMB level, and falsely
 264                  * claims capability (also get here for DFS case which should be
 265                  * rare for path not covered on files)
 266                  */
 267         }
 268 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 269
 270         desired_access = 0;
 271         if (OPEN_FMODE(oflags) & FMODE_READ)
 272                 desired_access |= GENERIC_READ; /* is this too little? */
 273         if (OPEN_FMODE(oflags) & FMODE_WRITE)
 274                 desired_access |= GENERIC_WRITE;
 275         if (rdwr_for_fscache == 1)
 276                 desired_access |= GENERIC_READ;
 277
 278         disposition = FILE_OVERWRITE_IF;
 279         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 280                 disposition = FILE_CREATE;
 281         else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
 282                 disposition = FILE_OVERWRITE_IF;
 283         else if ((oflags & O_CREAT) == O_CREAT)
 284                 disposition = FILE_OPEN_IF;
 285         else
 286                 cifs_dbg(FYI, "Create flag not set in create function\n");
 287
 288         /*
 289          * BB add processing to set equivalent of mode - e.g. via CreateX with
 290          * ACLs
 291          */
 292
 293         if (!server->ops->open) {
 294                 rc = -ENOSYS;
 295                 goto out;
 296         }
 297
 298         /*
 299          * if we're not using unix extensions, see if we need to set
 300          * ATTR_READONLY on the create call
 301          */
 302         if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
 303                 create_options |= CREATE_OPTION_READONLY;
 304
 305 retry_open:
 306         oparms = (struct cifs_open_parms) {
 307                 .tcon = tcon,
 308                 .cifs_sb = cifs_sb,
 309                 .desired_access = desired_access,
 310                 .create_options = cifs_create_options(cifs_sb, create_options),
 311                 .disposition = disposition,
 312                 .path = full_path,
 313                 .fid = fid,
 314                 .mode = mode,
 315         };
 316         rc = server->ops->open(xid, &oparms, oplock, buf);
 317         if (rc) {
 318                 cifs_dbg(FYI, "cifs_create returned 0x%x\n", rc);
 319                 if (rc == -EACCES && rdwr_for_fscache == 1) {
 320                         desired_access &= ~GENERIC_READ;
 321                         rdwr_for_fscache = 2;
 322                         goto retry_open;
 323                 }
 324                 goto out;
 325         }
 326         if (rdwr_for_fscache == 2)
 327                 cifs_invalidate_cache(inode, FSCACHE_INVAL_DIO_WRITE);
 328
 329 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 330         /*
 331          * If Open reported that we actually created a file then we now have to
 332          * set the mode if possible.
 333          */
 334         if ((tcon->unix_ext) && (*oplock & CIFS_CREATE_ACTION)) {
 335                 struct cifs_unix_set_info_args args = {
 336                                 .mode   = mode,
 337                                 .ctime  = NO_CHANGE_64,
 338                                 .atime  = NO_CHANGE_64,
 339                                 .mtime  = NO_CHANGE_64,
 340                                 .device = 0,
 341                 };
 342
 343                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 344                         args.uid = current_fsuid();
 345                         if (inode->i_mode & S_ISGID)
 346                                 args.gid = inode->i_gid;
 347                         else
 348                                 args.gid = current_fsgid();
 349                 } else {
 350                         args.uid = INVALID_UID; /* no change */
 351                         args.gid = INVALID_GID; /* no change */
 352                 }
 353                 CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
 354                                        current->tgid);
 355         } else {
 356                 /*
 357                  * BB implement mode setting via Windows security
 358                  * descriptors e.g.
 359                  */
 360                 /* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
 361
 362                 /* Could set r/o dos attribute if mode & 0222 == 0 */
 363         }
 364
 365 cifs_create_get_file_info:
 366         /* server might mask mode so we have to query for it */
 367         if (tcon->unix_ext)
 368                 rc = cifs_get_inode_info_unix(&newinode, full_path, inode->i_sb,
 369                                               xid);
 370         else {
 371 #else
 372         {
 373 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 374                 /* TODO: Add support for calling POSIX query info here, but passing in fid */
 375                 rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb, xid, fid);
 376                 if (newinode) {
 377                         if (server->ops->set_lease_key)
 378                                 server->ops->set_lease_key(newinode, fid);
 379                         if ((*oplock & CIFS_CREATE_ACTION) && S_ISREG(newinode->i_mode)) {
 380                                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
 381                                         newinode->i_mode = mode;
 382                                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 383                                         newinode->i_uid = current_fsuid();
 384                                         if (inode->i_mode & S_ISGID)
 385                                                 newinode->i_gid = inode->i_gid;
 386                                         else
 387                                                 newinode->i_gid = current_fsgid();
 388                                 }
 389                         }
 390                 }
 391         }
 392
 393 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 394 cifs_create_set_dentry:
 395 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 396         if (rc != 0) {
 397                 cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
 398                          rc);
 399                 goto out_err;
 400         }
 401
 402         if (newinode)
 403                 if (S_ISDIR(newinode->i_mode)) {
 404                         rc = -EISDIR;
 405                         goto out_err;
 406                 }
 407
 408         d_drop(direntry);
 409         d_add(direntry, newinode);
 410
 411 out:
 412         free_dentry_path(page);
 413         return rc;
 414
 415 out_err:
 416         if (server->ops->close)
 417                 server->ops->close(xid, tcon, fid);
 418         if (newinode)
 419                 iput(newinode);
 420         goto out;
 421 }
 422
 423 int
 424 cifs_atomic_open(struct inode *inode, struct dentry *direntry,
 425                  struct file *file, unsigned oflags, umode_t mode)
 426 {
 427         int rc;
 428         unsigned int xid;
 429         struct tcon_link *tlink;
 430         struct cifs_tcon *tcon;
 431         struct TCP_Server_Info *server;
 432         struct cifs_fid fid = {};
 433         struct cifs_pending_open open;
 434         __u32 oplock;
 435         struct cifsFileInfo *file_info;
 436         struct cifs_open_info_data buf = {};
 437
 438         if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
 439                 return -EIO;
 440
 441         /*
 442          * Posix open is only called (at lookup time) for file create now. For
 443          * opens (rather than creates), because we do not know if it is a file
 444          * or directory yet, and current Samba no longer allows us to do posix
 445          * open on dirs, we could end up wasting an open call on what turns out
 446          * to be a dir. For file opens, we wait to call posix open till
 447          * cifs_open.  It could be added to atomic_open in the future but the
 448          * performance tradeoff of the extra network request when EISDIR or
 449          * EACCES is returned would have to be weighed against the 50% reduction
 450          * in network traffic in the other paths.
 451          */
 452         if (!(oflags & O_CREAT)) {
 453                 struct dentry *res;
 454
 455                 /*
 456                  * Check for hashed negative dentry. We have already revalidated
 457                  * the dentry and it is fine. No need to perform another lookup.
 458                  */
 459                 if (!d_in_lookup(direntry))
 460                         return -ENOENT;
 461
 462                 res = cifs_lookup(inode, direntry, 0);
 463                 if (IS_ERR(res))
 464                         return PTR_ERR(res);
 465
 466                 return finish_no_open(file, res);
 467         }
 468
 469         xid = get_xid();
 470
 471         cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 472                  inode, direntry, direntry);
 473
 474         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
 475         if (IS_ERR(tlink)) {
 476                 rc = PTR_ERR(tlink);
 477                 goto out_free_xid;
 478         }
 479
 480         tcon = tlink_tcon(tlink);
 481
 482         rc = check_name(direntry, tcon);
 483         if (rc)
 484                 goto out;
 485
 486         server = tcon->ses->server;
 487
 488         if (server->ops->new_lease_key)
 489                 server->ops->new_lease_key(&fid);
 490
 491         cifs_add_pending_open(&fid, tlink, &open);
 492
 493         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
 494                             &oplock, &fid, &buf);
 495         if (rc) {
 496                 cifs_del_pending_open(&open);
 497                 goto out;
 498         }
 499
 500         if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 501                 file->f_mode |= FMODE_CREATED;
 502
 503         rc = finish_open(file, direntry, generic_file_open);
 504         if (rc) {
 505                 if (server->ops->close)
 506                         server->ops->close(xid, tcon, &fid);
 507                 cifs_del_pending_open(&open);
 508                 goto out;
 509         }
 510
 511         if (file->f_flags & O_DIRECT &&
 512             CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
 513                 if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
 514                         file->f_op = &cifs_file_direct_nobrl_ops;
 515                 else
 516                         file->f_op = &cifs_file_direct_ops;
 517                 }
 518
 519         file_info = cifs_new_fileinfo(&fid, file, tlink, oplock, buf.symlink_target);
 520         if (file_info == NULL) {
 521                 if (server->ops->close)
 522                         server->ops->close(xid, tcon, &fid);
 523                 cifs_del_pending_open(&open);
 524                 rc = -ENOMEM;
 525                 goto out;
 526         }
 527
 528         fscache_use_cookie(cifs_inode_cookie(file_inode(file)),
 529                            file->f_mode & FMODE_WRITE);
 530
 531 out:
 532         cifs_put_tlink(tlink);
 533 out_free_xid:
 534         free_xid(xid);
 535         cifs_free_open_info(&buf);
 536         return rc;
 537 }
 538
 539 int cifs_create(struct user_namespace *mnt_userns, struct inode *inode,
 540                 struct dentry *direntry, umode_t mode, bool excl)
 541 {
 542         int rc;
 543         unsigned int xid = get_xid();
 544         /*
 545          * BB below access is probably too much for mknod to request
 546          *    but we have to do query and setpathinfo so requesting
 547          *    less could fail (unless we want to request getatr and setatr
 548          *    permissions (only).  At least for POSIX we do not have to
 549          *    request so much.
 550          */
 551         unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
 552         struct tcon_link *tlink;
 553         struct cifs_tcon *tcon;
 554         struct TCP_Server_Info *server;
 555         struct cifs_fid fid;
 556         __u32 oplock;
 557         struct cifs_open_info_data buf = {};
 558
 559         cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 560                  inode, direntry, direntry);
 561
 562         if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb)))) {
 563                 rc = -EIO;
 564                 goto out_free_xid;
 565         }
 566
 567         tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
 568         rc = PTR_ERR(tlink);
 569         if (IS_ERR(tlink))
 570                 goto out_free_xid;
 571
 572         tcon = tlink_tcon(tlink);
 573         server = tcon->ses->server;
 574
 575         if (server->ops->new_lease_key)
 576                 server->ops->new_lease_key(&fid);
 577
 578         rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, &oplock, &fid, &buf);
 579         if (!rc && server->ops->close)
 580                 server->ops->close(xid, tcon, &fid);
 581
 582         cifs_free_open_info(&buf);
 583         cifs_put_tlink(tlink);
 584 out_free_xid:
 585         free_xid(xid);
 586         return rc;
 587 }
 588
 589 int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
 590                struct dentry *direntry, umode_t mode, dev_t device_number)
 591 {
 592         int rc = -EPERM;
 593         unsigned int xid;
 594         struct cifs_sb_info *cifs_sb;
 595         struct tcon_link *tlink;
 596         struct cifs_tcon *tcon;
 597         const char *full_path;
 598         void *page;
 599
 600         if (!old_valid_dev(device_number))
 601                 return -EINVAL;
 602
 603         cifs_sb = CIFS_SB(inode->i_sb);
 604         if (unlikely(cifs_forced_shutdown(cifs_sb)))
 605                 return -EIO;
 606
 607         tlink = cifs_sb_tlink(cifs_sb);
 608         if (IS_ERR(tlink))
 609                 return PTR_ERR(tlink);
 610
 611         page = alloc_dentry_path();
 612         tcon = tlink_tcon(tlink);
 613         xid = get_xid();
 614
 615         full_path = build_path_from_dentry(direntry, page);
 616         if (IS_ERR(full_path)) {
 617                 rc = PTR_ERR(full_path);
 618                 goto mknod_out;
 619         }
 620
 621         rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
 622                                                full_path, mode,
 623                                                device_number);
 624
 625 mknod_out:
 626         free_dentry_path(page);
 627         free_xid(xid);
 628         cifs_put_tlink(tlink);
 629         return rc;
 630 }
 631
 632 struct dentry *
 633 cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
 634             unsigned int flags)
 635 {
 636         unsigned int xid;
 637         int rc = 0; /* to get around spurious gcc warning, set to zero here */
 638         struct cifs_sb_info *cifs_sb;
 639         struct tcon_link *tlink;
 640         struct cifs_tcon *pTcon;
 641         struct inode *newInode = NULL;
 642         const char *full_path;
 643         void *page;
 644         int retry_count = 0;
 645
 646         xid = get_xid();
 647
 648         cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
 649                  parent_dir_inode, direntry, direntry);
 650
 651         /* check whether path exists */
 652
 653         cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
 654         tlink = cifs_sb_tlink(cifs_sb);
 655         if (IS_ERR(tlink)) {
 656                 free_xid(xid);
 657                 return ERR_CAST(tlink);
 658         }
 659         pTcon = tlink_tcon(tlink);
 660
 661         rc = check_name(direntry, pTcon);
 662         if (unlikely(rc)) {
 663                 cifs_put_tlink(tlink);
 664                 free_xid(xid);
 665                 return ERR_PTR(rc);
 666         }
 667
 668         /* can not grab the rename sem here since it would
 669         deadlock in the cases (beginning of sys_rename itself)
 670         in which we already have the sb rename sem */
 671         page = alloc_dentry_path();
 672         full_path = build_path_from_dentry(direntry, page);
 673         if (IS_ERR(full_path)) {
 674                 cifs_put_tlink(tlink);
 675                 free_xid(xid);
 676                 free_dentry_path(page);
 677                 return ERR_CAST(full_path);
 678         }
 679
 680         if (d_really_is_positive(direntry)) {
 681                 cifs_dbg(FYI, "non-NULL inode in lookup\n");
 682         } else {
 683                 cifs_dbg(FYI, "NULL inode in lookup\n");
 684         }
 685         cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
 686                  full_path, d_inode(direntry));
 687
 688 again:
 689         if (pTcon->posix_extensions)
 690                 rc = smb311_posix_get_inode_info(&newInode, full_path, parent_dir_inode->i_sb, xid);
 691         else if (pTcon->unix_ext) {
 692                 rc = cifs_get_inode_info_unix(&newInode, full_path,
 693                                               parent_dir_inode->i_sb, xid);
 694         } else {
 695                 rc = cifs_get_inode_info(&newInode, full_path, NULL,
 696                                 parent_dir_inode->i_sb, xid, NULL);
 697         }
 698
 699         if (rc == 0) {
 700                 /* since paths are not looked up by component - the parent
 701                    directories are presumed to be good here */
 702                 renew_parental_timestamps(direntry);
 703         } else if (rc == -EAGAIN && retry_count++ < 10) {
 704                 goto again;
 705         } else if (rc == -ENOENT) {
 706                 cifs_set_time(direntry, jiffies);
 707                 newInode = NULL;
 708         } else {
 709                 if (rc != -EACCES) {
 710                         cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
 711                         /* We special case check for Access Denied - since that
 712                         is a common return code */
 713                 }
 714                 newInode = ERR_PTR(rc);
 715         }
 716         free_dentry_path(page);
 717         cifs_put_tlink(tlink);
 718         free_xid(xid);
 719         return d_splice_alias(newInode, direntry);
 720 }
 721
 722 static int
 723 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
 724 {
 725         struct inode *inode;
 726         int rc;
 727
 728         if (flags & LOOKUP_RCU)
 729                 return -ECHILD;
 730
 731         if (d_really_is_positive(direntry)) {
 732                 inode = d_inode(direntry);
 733                 if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
 734                         CIFS_I(inode)->time = 0; /* force reval */
 735
 736                 rc = cifs_revalidate_dentry(direntry);
 737                 if (rc) {
 738                         cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
 739                         switch (rc) {
 740                         case -ENOENT:
 741                         case -ESTALE:
 742                                 /*
 743                                  * Those errors mean the dentry is invalid
 744                                  * (file was deleted or recreated)
 745                                  */
 746                                 return 0;
 747                         default:
 748                                 /*
 749                                  * Otherwise some unexpected error happened
 750                                  * report it as-is to VFS layer
 751                                  */
 752                                 return rc;
 753                         }
 754                 }
 755                 else {
 756                         /*
 757                          * If the inode wasn't known to be a dfs entry when
 758                          * the dentry was instantiated, such as when created
 759                          * via ->readdir(), it needs to be set now since the
 760                          * attributes will have been updated by
 761                          * cifs_revalidate_dentry().
 762                          */
 763                         if (IS_AUTOMOUNT(inode) &&
 764                            !(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
 765                                 spin_lock(&direntry->d_lock);
 766                                 direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
 767                                 spin_unlock(&direntry->d_lock);
 768                         }
 769
 770                         return 1;
 771                 }
 772         }
 773
 774         /*
 775          * This may be nfsd (or something), anyway, we can't see the
 776          * intent of this. So, since this can be for creation, drop it.
 777          */
 778         if (!flags)
 779                 return 0;
 780
 781         /*
 782          * Drop the negative dentry, in order to make sure to use the
 783          * case sensitive name which is specified by user if this is
 784          * for creation.
 785          */
 786         if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
 787                 return 0;
 788
 789         if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
 790                 return 0;
 791
 792         return 1;
 793 }
 794
 795 /* static int cifs_d_delete(struct dentry *direntry)
 796 {
 797         int rc = 0;
 798
 799         cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
 800
 801         return rc;
 802 }     */
 803
 804 const struct dentry_operations cifs_dentry_ops = {
 805         .d_revalidate = cifs_d_revalidate,
 806         .d_automount = cifs_dfs_d_automount,
 807 /* d_delete:       cifs_d_delete,      */ /* not needed except for debugging */
 808 };
 809
 810 static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
 811 {
 812         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 813         unsigned long hash;
 814         wchar_t c;
 815         int i, charlen;
 816
 817         hash = init_name_hash(dentry);
 818         for (i = 0; i < q->len; i += charlen) {
 819                 charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
 820                 /* error out if we can't convert the character */
 821                 if (unlikely(charlen < 0))
 822                         return charlen;
 823                 hash = partial_name_hash(cifs_toupper(c), hash);
 824         }
 825         q->hash = end_name_hash(hash);
 826
 827         return 0;
 828 }
 829
 830 static int cifs_ci_compare(const struct dentry *dentry,
 831                 unsigned int len, const char *str, const struct qstr *name)
 832 {
 833         struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 834         wchar_t c1, c2;
 835         int i, l1, l2;
 836
 837         /*
 838          * We make the assumption here that uppercase characters in the local
 839          * codepage are always the same length as their lowercase counterparts.
 840          *
 841          * If that's ever not the case, then this will fail to match it.
 842          */
 843         if (name->len != len)
 844                 return 1;
 845
 846         for (i = 0; i < len; i += l1) {
 847                 /* Convert characters in both strings to UTF-16. */
 848                 l1 = codepage->char2uni(&str[i], len - i, &c1);
 849                 l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
 850
 851                 /*
 852                  * If we can't convert either character, just declare it to
 853                  * be 1 byte long and compare the original byte.
 854                  */
 855                 if (unlikely(l1 < 0 && l2 < 0)) {
 856                         if (str[i] != name->name[i])
 857                                 return 1;
 858                         l1 = 1;
 859                         continue;
 860                 }
 861
 862                 /*
 863                  * Here, we again ass|u|me that upper/lowercase versions of
 864                  * a character are the same length in the local NLS.
 865                  */
 866                 if (l1 != l2)
 867                         return 1;
 868
 869                 /* Now compare uppercase versions of these characters */
 870                 if (cifs_toupper(c1) != cifs_toupper(c2))
 871                         return 1;
 872         }
 873
 874         return 0;
 875 }
 876
 877 const struct dentry_operations cifs_ci_dentry_ops = {
 878         .d_revalidate = cifs_d_revalidate,
 879         .d_hash = cifs_ci_hash,
 880         .d_compare = cifs_ci_compare,
 881         .d_automount = cifs_dfs_d_automount,
 882 };