smb/client/readdir.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   Directory search handling
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2004, 2008
   7  *   Copyright (C) Red Hat, Inc., 2011
   8  *   Author(s): Steve French (sfrench@us.ibm.com)
   9  *
  10  */
  11 #include <linux/fs.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/slab.h>
  14 #include <linux/stat.h>
  15 #include "cifspdu.h"
  16 #include "cifsglob.h"
  17 #include "cifsproto.h"
  18 #include "cifs_unicode.h"
  19 #include "cifs_debug.h"
  20 #include "cifs_fs_sb.h"
  21 #include "cifsfs.h"
  22 #include "smb2proto.h"
  23 #include "fs_context.h"
  24 #include "cached_dir.h"
  25
  26 /*
  27  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  28  * characters alloc more to account for such multibyte target UTF-8
  29  * characters.
  30  */
  31 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  32
  33 #ifdef CONFIG_CIFS_DEBUG2
  34 static void dump_cifs_file_struct(struct file *file, char *label)
  35 {
  36         struct cifsFileInfo *cf;
  37
  38         if (file) {
  39                 cf = file->private_data;
  40                 if (cf == NULL) {
  41                         cifs_dbg(FYI, "empty cifs private file data\n");
  42                         return;
  43                 }
  44                 if (cf->invalidHandle)
  45                         cifs_dbg(FYI, "Invalid handle\n");
  46                 if (cf->srch_inf.endOfSearch)
  47                         cifs_dbg(FYI, "end of search\n");
  48                 if (cf->srch_inf.emptyDir)
  49                         cifs_dbg(FYI, "empty dir\n");
  50         }
  51 }
  52 #else
  53 static inline void dump_cifs_file_struct(struct file *file, char *label)
  54 {
  55 }
  56 #endif /* DEBUG2 */
  57
  58 /*
  59  * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
  60  *
  61  * Find the dentry that matches "name". If there isn't one, create one. If it's
  62  * a negative dentry or the uniqueid or filetype(mode) changed,
  63  * then drop it and recreate it.
  64  */
  65 static void
  66 cifs_prime_dcache(struct dentry *parent, struct qstr *name,
  67                     struct cifs_fattr *fattr)
  68 {
  69         struct dentry *dentry, *alias;
  70         struct inode *inode;
  71         struct super_block *sb = parent->d_sb;
  72         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
  73         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
  74
  75         cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
  76
  77         dentry = d_hash_and_lookup(parent, name);
  78         if (!dentry) {
  79                 /*
  80                  * If we know that the inode will need to be revalidated
  81                  * immediately, then don't create a new dentry for it.
  82                  * We'll end up doing an on the wire call either way and
  83                  * this spares us an invalidation.
  84                  */
  85                 if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
  86                         return;
  87 retry:
  88                 dentry = d_alloc_parallel(parent, name, &wq);
  89         }
  90         if (IS_ERR(dentry))
  91                 return;
  92         if (!d_in_lookup(dentry)) {
  93                 inode = d_inode(dentry);
  94                 if (inode) {
  95                         if (d_mountpoint(dentry)) {
  96                                 dput(dentry);
  97                                 return;
  98                         }
  99                         /*
 100                          * If we're generating inode numbers, then we don't
 101                          * want to clobber the existing one with the one that
 102                          * the readdir code created.
 103                          */
 104                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
 105                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
 106
 107                         /* update inode in place
 108                          * if both i_ino and i_mode didn't change */
 109                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid &&
 110                             cifs_fattr_to_inode(inode, fattr) == 0) {
 111                                 dput(dentry);
 112                                 return;
 113                         }
 114                 }
 115                 d_invalidate(dentry);
 116                 dput(dentry);
 117                 goto retry;
 118         } else {
 119                 inode = cifs_iget(sb, fattr);
 120                 if (!inode)
 121                         inode = ERR_PTR(-ENOMEM);
 122                 alias = d_splice_alias(inode, dentry);
 123                 d_lookup_done(dentry);
 124                 if (alias && !IS_ERR(alias))
 125                         dput(alias);
 126         }
 127         dput(dentry);
 128 }
 129
 130 static bool reparse_file_needs_reval(const struct cifs_fattr *fattr)
 131 {
 132         if (!(fattr->cf_cifsattrs & ATTR_REPARSE))
 133                 return false;
 134         /*
 135          * The DFS tags should be only intepreted by server side as per
 136          * MS-FSCC 2.1.2.1, but let's include them anyway.
 137          *
 138          * Besides, if cf_cifstag is unset (0), then we still need it to be
 139          * revalidated to know exactly what reparse point it is.
 140          */
 141         switch (fattr->cf_cifstag) {
 142         case IO_REPARSE_TAG_DFS:
 143         case IO_REPARSE_TAG_DFSR:
 144         case IO_REPARSE_TAG_SYMLINK:
 145         case IO_REPARSE_TAG_NFS:
 146         case 0:
 147                 return true;
 148         }
 149         return false;
 150 }
 151
 152 static void
 153 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 154 {
 155         fattr->cf_uid = cifs_sb->ctx->linux_uid;
 156         fattr->cf_gid = cifs_sb->ctx->linux_gid;
 157
 158         /*
 159          * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they
 160          * are preferred by the Linux client in some cases since, unlike
 161          * the NFS reparse tag (or EAs), they don't require an extra query
 162          * to determine which type of special file they represent.
 163          * TODO: go through all documented  reparse tags to see if we can
 164          * reasonably map some of them to directories vs. files vs. symlinks
 165          */
 166         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 167                 fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode;
 168                 fattr->cf_dtype = DT_DIR;
 169         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_SYMLINK) {
 170                 fattr->cf_mode |= S_IFLNK | cifs_sb->ctx->file_mode;
 171                 fattr->cf_dtype = DT_LNK;
 172         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_FIFO) {
 173                 fattr->cf_mode |= S_IFIFO | cifs_sb->ctx->file_mode;
 174                 fattr->cf_dtype = DT_FIFO;
 175         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_AF_UNIX) {
 176                 fattr->cf_mode |= S_IFSOCK | cifs_sb->ctx->file_mode;
 177                 fattr->cf_dtype = DT_SOCK;
 178         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_CHR) {
 179                 fattr->cf_mode |= S_IFCHR | cifs_sb->ctx->file_mode;
 180                 fattr->cf_dtype = DT_CHR;
 181         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_BLK) {
 182                 fattr->cf_mode |= S_IFBLK | cifs_sb->ctx->file_mode;
 183                 fattr->cf_dtype = DT_BLK;
 184         } else { /* TODO: should we mark some other reparse points (like DFSR) as directories? */
 185                 fattr->cf_mode = S_IFREG | cifs_sb->ctx->file_mode;
 186                 fattr->cf_dtype = DT_REG;
 187         }
 188
 189         /*
 190          * We need to revalidate it further to make a decision about whether it
 191          * is a symbolic link, DFS referral or a reparse point with a direct
 192          * access like junctions, deduplicated files, NFS symlinks.
 193          */
 194         if (reparse_file_needs_reval(fattr))
 195                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 196
 197         /* non-unix readdir doesn't provide nlink */
 198         fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
 199
 200         if (fattr->cf_cifsattrs & ATTR_READONLY)
 201                 fattr->cf_mode &= ~S_IWUGO;
 202
 203         /*
 204          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 205          * mark it for revalidation so that "ls -l" will look right. It might
 206          * be super-slow, but if we don't do this then the ownership of files
 207          * may look wrong since the inodes may not have timed out by the time
 208          * "ls" does a stat() call on them.
 209          */
 210         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
 211             (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
 212                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 213
 214         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 215             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 216                 if (fattr->cf_eof == 0)  {
 217                         fattr->cf_mode &= ~S_IFMT;
 218                         fattr->cf_mode |= S_IFIFO;
 219                         fattr->cf_dtype = DT_FIFO;
 220                 } else {
 221                         /*
 222                          * trying to get the type and mode via SFU can be slow,
 223                          * so just call those regular files for now, and mark
 224                          * for reval
 225                          */
 226                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 227                 }
 228         }
 229 }
 230
 231 /* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
 232 static void
 233 cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
 234                     struct cifs_sb_info *cifs_sb)
 235 {
 236         struct smb2_posix_info_parsed parsed;
 237
 238         posix_info_parse(info, NULL, &parsed);
 239
 240         memset(fattr, 0, sizeof(*fattr));
 241         fattr->cf_uniqueid = le64_to_cpu(info->Inode);
 242         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 243         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 244
 245         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 246         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 247         fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
 248
 249         fattr->cf_nlink = le32_to_cpu(info->HardLinks);
 250         fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
 251
 252         /*
 253          * Since we set the inode type below we need to mask off
 254          * to avoid strange results if bits set above.
 255          * XXX: why not make server&client use the type bits?
 256          */
 257         fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
 258
 259         cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
 260                  le32_to_cpu(info->DeviceId),
 261                  le32_to_cpu(info->ReparseTag),
 262                  le32_to_cpu(info->Mode));
 263
 264         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 265                 fattr->cf_mode |= S_IFDIR;
 266                 fattr->cf_dtype = DT_DIR;
 267         } else {
 268                 /*
 269                  * mark anything that is not a dir as regular
 270                  * file. special files should have the REPARSE
 271                  * attribute and will be marked as needing revaluation
 272                  */
 273                 fattr->cf_mode |= S_IFREG;
 274                 fattr->cf_dtype = DT_REG;
 275         }
 276
 277         if (reparse_file_needs_reval(fattr))
 278                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 279
 280         sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER);
 281         sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP);
 282 }
 283
 284 static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
 285 {
 286         const FILE_DIRECTORY_INFO *fi = info;
 287
 288         memset(fattr, 0, sizeof(*fattr));
 289         fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
 290         fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
 291         fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
 292         fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
 293         fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);
 294         fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);
 295         fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);
 296 }
 297
 298 void
 299 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 300                        struct cifs_sb_info *cifs_sb)
 301 {
 302         __dir_info_to_fattr(fattr, info);
 303         cifs_fill_common_info(fattr, cifs_sb);
 304 }
 305
 306 static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
 307                                        const void *info,
 308                                        struct cifs_sb_info *cifs_sb)
 309 {
 310         const FILE_FULL_DIRECTORY_INFO *di = info;
 311
 312         __dir_info_to_fattr(fattr, info);
 313
 314         /* See MS-FSCC 2.4.14, 2.4.19 */
 315         if (fattr->cf_cifsattrs & ATTR_REPARSE)
 316                 fattr->cf_cifstag = le32_to_cpu(di->EaSize);
 317         cifs_fill_common_info(fattr, cifs_sb);
 318 }
 319
 320 static void
 321 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 322                        struct cifs_sb_info *cifs_sb)
 323 {
 324         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 325
 326         memset(fattr, 0, sizeof(*fattr));
 327         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 328                                             info->LastAccessTime, offset);
 329         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 330                                             info->LastWriteTime, offset);
 331         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 332                                             info->LastWriteTime, offset);
 333
 334         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 335         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 336         fattr->cf_eof = le32_to_cpu(info->DataSize);
 337
 338         cifs_fill_common_info(fattr, cifs_sb);
 339 }
 340
 341 /* BB eventually need to add the following helper function to
 342       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 343       we try to do FindFirst on (NTFS) directory symlinks */
 344 /*
 345 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 346                              unsigned int xid)
 347 {
 348         __u16 fid;
 349         int len;
 350         int oplock = 0;
 351         int rc;
 352         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 353         char *tmpbuffer;
 354
 355         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 356                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 357                         cifs_sb->local_nls,
 358                         cifs_remap(cifs_sb);
 359         if (!rc) {
 360                 tmpbuffer = kmalloc(maxpath);
 361                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 362                                 tmpbuffer,
 363                                 maxpath -1,
 364                                 fid,
 365                                 cifs_sb->local_nls);
 366                 if (CIFSSMBClose(xid, ptcon, fid)) {
 367                         cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
 368                 }
 369         }
 370 }
 371  */
 372
 373 static int
 374 _initiate_cifs_search(const unsigned int xid, struct file *file,
 375                      const char *full_path)
 376 {
 377         __u16 search_flags;
 378         int rc = 0;
 379         struct cifsFileInfo *cifsFile;
 380         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 381         struct tcon_link *tlink = NULL;
 382         struct cifs_tcon *tcon;
 383         struct TCP_Server_Info *server;
 384
 385         if (file->private_data == NULL) {
 386                 tlink = cifs_sb_tlink(cifs_sb);
 387                 if (IS_ERR(tlink))
 388                         return PTR_ERR(tlink);
 389
 390                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 391                 if (cifsFile == NULL) {
 392                         rc = -ENOMEM;
 393                         goto error_exit;
 394                 }
 395                 spin_lock_init(&cifsFile->file_info_lock);
 396                 file->private_data = cifsFile;
 397                 cifsFile->tlink = cifs_get_tlink(tlink);
 398                 tcon = tlink_tcon(tlink);
 399         } else {
 400                 cifsFile = file->private_data;
 401                 tcon = tlink_tcon(cifsFile->tlink);
 402         }
 403
 404         server = tcon->ses->server;
 405
 406         if (!server->ops->query_dir_first) {
 407                 rc = -ENOSYS;
 408                 goto error_exit;
 409         }
 410
 411         cifsFile->invalidHandle = true;
 412         cifsFile->srch_inf.endOfSearch = false;
 413
 414         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
 415
 416 ffirst_retry:
 417         /* test for Unix extensions */
 418         /* but now check for them on the share/mount not on the SMB session */
 419         /* if (cap_unix(tcon->ses) { */
 420         if (tcon->unix_ext)
 421                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 422         else if (tcon->posix_extensions)
 423                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
 424         else if ((tcon->ses->capabilities &
 425                   tcon->ses->server->vals->cap_nt_find) == 0) {
 426                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 427         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 428                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 429         } else /* not srvinos - BB fixme add check for backlevel? */ {
 430                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_FULL_DIRECTORY_INFO;
 431         }
 432
 433         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 434         if (backup_cred(cifs_sb))
 435                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 436
 437         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 438                                           &cifsFile->fid, search_flags,
 439                                           &cifsFile->srch_inf);
 440
 441         if (rc == 0)
 442                 cifsFile->invalidHandle = false;
 443         /* BB add following call to handle readdir on new NTFS symlink errors
 444         else if STATUS_STOPPED_ON_SYMLINK
 445                 call get_symlink_reparse_path and retry with new path */
 446         else if ((rc == -EOPNOTSUPP) &&
 447                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 448                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 449                 goto ffirst_retry;
 450         }
 451 error_exit:
 452         cifs_put_tlink(tlink);
 453         return rc;
 454 }
 455
 456 static int
 457 initiate_cifs_search(const unsigned int xid, struct file *file,
 458                      const char *full_path)
 459 {
 460         int rc, retry_count = 0;
 461
 462         do {
 463                 rc = _initiate_cifs_search(xid, file, full_path);
 464                 /*
 465                  * If we don't have enough credits to start reading the
 466                  * directory just try again after short wait.
 467                  */
 468                 if (rc != -EDEADLK)
 469                         break;
 470
 471                 usleep_range(512, 2048);
 472         } while (retry_count++ < 5);
 473
 474         return rc;
 475 }
 476
 477 /* return length of unicode string in bytes */
 478 static int cifs_unicode_bytelen(const char *str)
 479 {
 480         int len;
 481         const __le16 *ustr = (const __le16 *)str;
 482
 483         for (len = 0; len <= PATH_MAX; len++) {
 484                 if (ustr[len] == 0)
 485                         return len << 1;
 486         }
 487         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
 488         return len << 1;
 489 }
 490
 491 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 492 {
 493         char *new_entry;
 494         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 495
 496         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 497                 FIND_FILE_STANDARD_INFO *pfData;
 498                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 499
 500                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 501                                 pfData->FileNameLength;
 502         } else {
 503                 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
 504
 505                 if (old_entry + next_offset < old_entry) {
 506                         cifs_dbg(VFS, "Invalid offset %u\n", next_offset);
 507                         return NULL;
 508                 }
 509                 new_entry = old_entry + next_offset;
 510         }
 511         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
 512         /* validate that new_entry is not past end of SMB */
 513         if (new_entry >= end_of_smb) {
 514                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
 515                          new_entry, end_of_smb, old_entry);
 516                 return NULL;
 517         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 518                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 519                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 520                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 521                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
 522                          new_entry, end_of_smb);
 523                 return NULL;
 524         } else
 525                 return new_entry;
 526
 527 }
 528
 529 struct cifs_dirent {
 530         const char      *name;
 531         size_t          namelen;
 532         u32             resume_key;
 533         u64             ino;
 534 };
 535
 536 static void cifs_fill_dirent_posix(struct cifs_dirent *de,
 537                                    const struct smb2_posix_info *info)
 538 {
 539         struct smb2_posix_info_parsed parsed;
 540
 541         /* payload should have already been checked at this point */
 542         if (posix_info_parse(info, NULL, &parsed) < 0) {
 543                 cifs_dbg(VFS, "Invalid POSIX info payload\n");
 544                 return;
 545         }
 546
 547         de->name = parsed.name;
 548         de->namelen = parsed.name_len;
 549         de->resume_key = info->Ignored;
 550         de->ino = le64_to_cpu(info->Inode);
 551 }
 552
 553 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 554                 const FILE_UNIX_INFO *info, bool is_unicode)
 555 {
 556         de->name = &info->FileName[0];
 557         if (is_unicode)
 558                 de->namelen = cifs_unicode_bytelen(de->name);
 559         else
 560                 de->namelen = strnlen(de->name, PATH_MAX);
 561         de->resume_key = info->ResumeKey;
 562         de->ino = le64_to_cpu(info->basic.UniqueId);
 563 }
 564
 565 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 566                 const FILE_DIRECTORY_INFO *info)
 567 {
 568         de->name = &info->FileName[0];
 569         de->namelen = le32_to_cpu(info->FileNameLength);
 570         de->resume_key = info->FileIndex;
 571 }
 572
 573 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 574                 const FILE_FULL_DIRECTORY_INFO *info)
 575 {
 576         de->name = &info->FileName[0];
 577         de->namelen = le32_to_cpu(info->FileNameLength);
 578         de->resume_key = info->FileIndex;
 579 }
 580
 581 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 582                 const SEARCH_ID_FULL_DIR_INFO *info)
 583 {
 584         de->name = &info->FileName[0];
 585         de->namelen = le32_to_cpu(info->FileNameLength);
 586         de->resume_key = info->FileIndex;
 587         de->ino = le64_to_cpu(info->UniqueId);
 588 }
 589
 590 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 591                 const FILE_BOTH_DIRECTORY_INFO *info)
 592 {
 593         de->name = &info->FileName[0];
 594         de->namelen = le32_to_cpu(info->FileNameLength);
 595         de->resume_key = info->FileIndex;
 596 }
 597
 598 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 599                 const FIND_FILE_STANDARD_INFO *info)
 600 {
 601         de->name = &info->FileName[0];
 602         /* one byte length, no endianess conversion */
 603         de->namelen = info->FileNameLength;
 604         de->resume_key = info->ResumeKey;
 605 }
 606
 607 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 608                 u16 level, bool is_unicode)
 609 {
 610         memset(de, 0, sizeof(*de));
 611
 612         switch (level) {
 613         case SMB_FIND_FILE_POSIX_INFO:
 614                 cifs_fill_dirent_posix(de, info);
 615                 break;
 616         case SMB_FIND_FILE_UNIX:
 617                 cifs_fill_dirent_unix(de, info, is_unicode);
 618                 break;
 619         case SMB_FIND_FILE_DIRECTORY_INFO:
 620                 cifs_fill_dirent_dir(de, info);
 621                 break;
 622         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 623                 cifs_fill_dirent_full(de, info);
 624                 break;
 625         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 626                 cifs_fill_dirent_search(de, info);
 627                 break;
 628         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 629                 cifs_fill_dirent_both(de, info);
 630                 break;
 631         case SMB_FIND_FILE_INFO_STANDARD:
 632                 cifs_fill_dirent_std(de, info);
 633                 break;
 634         default:
 635                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
 636                 return -EINVAL;
 637         }
 638
 639         return 0;
 640 }
 641
 642 #define UNICODE_DOT cpu_to_le16(0x2e)
 643
 644 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 645 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 646 {
 647         int rc = 0;
 648
 649         if (!de->name)
 650                 return 0;
 651
 652         if (is_unicode) {
 653                 __le16 *ufilename = (__le16 *)de->name;
 654                 if (de->namelen == 2) {
 655                         /* check for . */
 656                         if (ufilename[0] == UNICODE_DOT)
 657                                 rc = 1;
 658                 } else if (de->namelen == 4) {
 659                         /* check for .. */
 660                         if (ufilename[0] == UNICODE_DOT &&
 661                             ufilename[1] == UNICODE_DOT)
 662                                 rc = 2;
 663                 }
 664         } else /* ASCII */ {
 665                 if (de->namelen == 1) {
 666                         if (de->name[0] == '.')
 667                                 rc = 1;
 668                 } else if (de->namelen == 2) {
 669                         if (de->name[0] == '.' && de->name[1] == '.')
 670                                 rc = 2;
 671                 }
 672         }
 673
 674         return rc;
 675 }
 676
 677 /* Check if directory that we are searching has changed so we can decide
 678    whether we can use the cached search results from the previous search */
 679 static int is_dir_changed(struct file *file)
 680 {
 681         struct inode *inode = file_inode(file);
 682         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 683
 684         if (cifsInfo->time == 0)
 685                 return 1; /* directory was changed, perhaps due to unlink */
 686         else
 687                 return 0;
 688
 689 }
 690
 691 static int cifs_save_resume_key(const char *current_entry,
 692         struct cifsFileInfo *file_info)
 693 {
 694         struct cifs_dirent de;
 695         int rc;
 696
 697         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 698                               file_info->srch_inf.unicode);
 699         if (!rc) {
 700                 file_info->srch_inf.presume_name = de.name;
 701                 file_info->srch_inf.resume_name_len = de.namelen;
 702                 file_info->srch_inf.resume_key = de.resume_key;
 703         }
 704         return rc;
 705 }
 706
 707 /*
 708  * Find the corresponding entry in the search. Note that the SMB server returns
 709  * search entries for . and .. which complicates logic here if we choose to
 710  * parse for them and we do not assume that they are located in the findfirst
 711  * return buffer. We start counting in the buffer with entry 2 and increment for
 712  * every entry (do not increment for . or .. entry).
 713  */
 714 static int
 715 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
 716                 struct file *file, const char *full_path,
 717                 char **current_entry, int *num_to_ret)
 718 {
 719         __u16 search_flags;
 720         int rc = 0;
 721         int pos_in_buf = 0;
 722         loff_t first_entry_in_buffer;
 723         loff_t index_to_find = pos;
 724         struct cifsFileInfo *cfile = file->private_data;
 725         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 726         struct TCP_Server_Info *server = tcon->ses->server;
 727         /* check if index in the buffer */
 728
 729         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 730                 return -ENOSYS;
 731
 732         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 733                 return -ENOENT;
 734
 735         *current_entry = NULL;
 736         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 737                                         cfile->srch_inf.entries_in_buffer;
 738
 739         /*
 740          * If first entry in buf is zero then is first buffer
 741          * in search response data which means it is likely . and ..
 742          * will be in this buffer, although some servers do not return
 743          * . and .. for the root of a drive and for those we need
 744          * to start two entries earlier.
 745          */
 746
 747         dump_cifs_file_struct(file, "In fce ");
 748         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 749              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 750                 /* close and restart search */
 751                 cifs_dbg(FYI, "search backing up - close and restart search\n");
 752                 spin_lock(&cfile->file_info_lock);
 753                 if (server->ops->dir_needs_close(cfile)) {
 754                         cfile->invalidHandle = true;
 755                         spin_unlock(&cfile->file_info_lock);
 756                         if (server->ops->close_dir)
 757                                 server->ops->close_dir(xid, tcon, &cfile->fid);
 758                 } else
 759                         spin_unlock(&cfile->file_info_lock);
 760                 if (cfile->srch_inf.ntwrk_buf_start) {
 761                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
 762                         if (cfile->srch_inf.smallBuf)
 763                                 cifs_small_buf_release(cfile->srch_inf.
 764                                                 ntwrk_buf_start);
 765                         else
 766                                 cifs_buf_release(cfile->srch_inf.
 767                                                 ntwrk_buf_start);
 768                         cfile->srch_inf.ntwrk_buf_start = NULL;
 769                 }
 770                 rc = initiate_cifs_search(xid, file, full_path);
 771                 if (rc) {
 772                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
 773                                  rc);
 774                         return rc;
 775                 }
 776                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 777                 if (cfile->srch_inf.last_entry)
 778                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 779         }
 780
 781         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 782         if (backup_cred(cifs_sb))
 783                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 784
 785         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 786                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 787                 cifs_dbg(FYI, "calling findnext2\n");
 788                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 789                                                  search_flags,
 790                                                  &cfile->srch_inf);
 791                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 792                 if (cfile->srch_inf.last_entry)
 793                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 794                 if (rc)
 795                         return -ENOENT;
 796         }
 797         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 798                 /* we found the buffer that contains the entry */
 799                 /* scan and find it */
 800                 int i;
 801                 char *cur_ent;
 802                 char *end_of_smb;
 803
 804                 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
 805                         cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
 806                         return -EIO;
 807                 }
 808
 809                 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 810                         server->ops->calc_smb_size(
 811                                         cfile->srch_inf.ntwrk_buf_start);
 812
 813                 cur_ent = cfile->srch_inf.srch_entries_start;
 814                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 815                                         - cfile->srch_inf.entries_in_buffer;
 816                 pos_in_buf = index_to_find - first_entry_in_buffer;
 817                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
 818
 819                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 820                         /* go entry by entry figuring out which is first */
 821                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 822                                                 cfile->srch_inf.info_level);
 823                 }
 824                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 825                         /* BB fixme - check if we should flag this error */
 826                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
 827                                  pos_in_buf, index_to_find, rc);
 828                 }
 829                 rc = 0;
 830                 *current_entry = cur_ent;
 831         } else {
 832                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
 833                 return 0;
 834         }
 835
 836         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 837                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
 838                 *num_to_ret = 0;
 839         } else
 840                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 841
 842         return rc;
 843 }
 844
 845 static bool emit_cached_dirents(struct cached_dirents *cde,
 846                                 struct dir_context *ctx)
 847 {
 848         struct cached_dirent *dirent;
 849         bool rc;
 850
 851         list_for_each_entry(dirent, &cde->entries, entry) {
 852                 /*
 853                  * Skip all early entries prior to the current lseek()
 854                  * position.
 855                  */
 856                 if (ctx->pos > dirent->pos)
 857                         continue;
 858                 /*
 859                  * We recorded the current ->pos value for the dirent
 860                  * when we stored it in the cache.
 861                  * However, this sequence of ->pos values may have holes
 862                  * in it, for example dot-dirs returned from the server
 863                  * are suppressed.
 864                  * Handle this bu forcing ctx->pos to be the same as the
 865                  * ->pos of the current dirent we emit from the cache.
 866                  * This means that when we emit these entries from the cache
 867                  * we now emit them with the same ->pos value as in the
 868                  * initial scan.
 869                  */
 870                 ctx->pos = dirent->pos;
 871                 rc = dir_emit(ctx, dirent->name, dirent->namelen,
 872                               dirent->fattr.cf_uniqueid,
 873                               dirent->fattr.cf_dtype);
 874                 if (!rc)
 875                         return rc;
 876                 ctx->pos++;
 877         }
 878         return true;
 879 }
 880
 881 static void update_cached_dirents_count(struct cached_dirents *cde,
 882                                         struct dir_context *ctx)
 883 {
 884         if (cde->ctx != ctx)
 885                 return;
 886         if (cde->is_valid || cde->is_failed)
 887                 return;
 888
 889         cde->pos++;
 890 }
 891
 892 static void finished_cached_dirents_count(struct cached_dirents *cde,
 893                                         struct dir_context *ctx)
 894 {
 895         if (cde->ctx != ctx)
 896                 return;
 897         if (cde->is_valid || cde->is_failed)
 898                 return;
 899         if (ctx->pos != cde->pos)
 900                 return;
 901
 902         cde->is_valid = 1;
 903 }
 904
 905 static void add_cached_dirent(struct cached_dirents *cde,
 906                               struct dir_context *ctx,
 907                               const char *name, int namelen,
 908                               struct cifs_fattr *fattr)
 909 {
 910         struct cached_dirent *de;
 911
 912         if (cde->ctx != ctx)
 913                 return;
 914         if (cde->is_valid || cde->is_failed)
 915                 return;
 916         if (ctx->pos != cde->pos) {
 917                 cde->is_failed = 1;
 918                 return;
 919         }
 920         de = kzalloc(sizeof(*de), GFP_ATOMIC);
 921         if (de == NULL) {
 922                 cde->is_failed = 1;
 923                 return;
 924         }
 925         de->namelen = namelen;
 926         de->name = kstrndup(name, namelen, GFP_ATOMIC);
 927         if (de->name == NULL) {
 928                 kfree(de);
 929                 cde->is_failed = 1;
 930                 return;
 931         }
 932         de->pos = ctx->pos;
 933
 934         memcpy(&de->fattr, fattr, sizeof(struct cifs_fattr));
 935
 936         list_add_tail(&de->entry, &cde->entries);
 937 }
 938
 939 static bool cifs_dir_emit(struct dir_context *ctx,
 940                           const char *name, int namelen,
 941                           struct cifs_fattr *fattr,
 942                           struct cached_fid *cfid)
 943 {
 944         bool rc;
 945         ino_t ino = cifs_uniqueid_to_ino_t(fattr->cf_uniqueid);
 946
 947         rc = dir_emit(ctx, name, namelen, ino, fattr->cf_dtype);
 948         if (!rc)
 949                 return rc;
 950
 951         if (cfid) {
 952                 mutex_lock(&cfid->dirents.de_mutex);
 953                 add_cached_dirent(&cfid->dirents, ctx, name, namelen,
 954                                   fattr);
 955                 mutex_unlock(&cfid->dirents.de_mutex);
 956         }
 957
 958         return rc;
 959 }
 960
 961 static int cifs_filldir(char *find_entry, struct file *file,
 962                         struct dir_context *ctx,
 963                         char *scratch_buf, unsigned int max_len,
 964                         struct cached_fid *cfid)
 965 {
 966         struct cifsFileInfo *file_info = file->private_data;
 967         struct super_block *sb = file_inode(file)->i_sb;
 968         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 969         struct cifs_dirent de = { NULL, };
 970         struct cifs_fattr fattr;
 971         struct qstr name;
 972         int rc = 0;
 973
 974         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 975                               file_info->srch_inf.unicode);
 976         if (rc)
 977                 return rc;
 978
 979         if (de.namelen > max_len) {
 980                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
 981                          de.namelen);
 982                 return -EINVAL;
 983         }
 984
 985         /* skip . and .. since we added them first */
 986         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 987                 return 0;
 988
 989         if (file_info->srch_inf.unicode) {
 990                 struct nls_table *nlt = cifs_sb->local_nls;
 991                 int map_type;
 992
 993                 map_type = cifs_remap(cifs_sb);
 994                 name.name = scratch_buf;
 995                 name.len =
 996                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 997                                         UNICODE_NAME_MAX,
 998                                         min_t(size_t, de.namelen,
 999                                               (size_t)max_len), nlt, map_type);
1000                 name.len -= nls_nullsize(nlt);
1001         } else {
1002                 name.name = de.name;
1003                 name.len = de.namelen;
1004         }
1005
1006         switch (file_info->srch_inf.info_level) {
1007         case SMB_FIND_FILE_POSIX_INFO:
1008                 cifs_posix_to_fattr(&fattr,
1009                                     (struct smb2_posix_info *)find_entry,
1010                                     cifs_sb);
1011                 break;
1012         case SMB_FIND_FILE_UNIX:
1013                 cifs_unix_basic_to_fattr(&fattr,
1014                                          &((FILE_UNIX_INFO *)find_entry)->basic,
1015                                          cifs_sb);
1016                 if (S_ISLNK(fattr.cf_mode))
1017                         fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
1018                 break;
1019         case SMB_FIND_FILE_INFO_STANDARD:
1020                 cifs_std_info_to_fattr(&fattr,
1021                                        (FIND_FILE_STANDARD_INFO *)find_entry,
1022                                        cifs_sb);
1023                 break;
1024         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
1025         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
1026                 cifs_fulldir_info_to_fattr(&fattr, find_entry, cifs_sb);
1027                 break;
1028         default:
1029                 cifs_dir_info_to_fattr(&fattr,
1030                                        (FILE_DIRECTORY_INFO *)find_entry,
1031                                        cifs_sb);
1032                 break;
1033         }
1034
1035         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
1036                 fattr.cf_uniqueid = de.ino;
1037         } else {
1038                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
1039                 cifs_autodisable_serverino(cifs_sb);
1040         }
1041
1042         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
1043             couldbe_mf_symlink(&fattr))
1044                 /*
1045                  * trying to get the type and mode can be slow,
1046                  * so just call those regular files for now, and mark
1047                  * for reval
1048                  */
1049                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
1050
1051         cifs_prime_dcache(file_dentry(file), &name, &fattr);
1052
1053         return !cifs_dir_emit(ctx, name.name, name.len,
1054                               &fattr, cfid);
1055 }
1056
1057
1058 int cifs_readdir(struct file *file, struct dir_context *ctx)
1059 {
1060         int rc = 0;
1061         unsigned int xid;
1062         int i;
1063         struct tcon_link *tlink = NULL;
1064         struct cifs_tcon *tcon;
1065         struct cifsFileInfo *cifsFile;
1066         char *current_entry;
1067         int num_to_fill = 0;
1068         char *tmp_buf = NULL;
1069         char *end_of_smb;
1070         unsigned int max_len;
1071         const char *full_path;
1072         void *page = alloc_dentry_path();
1073         struct cached_fid *cfid = NULL;
1074         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
1075
1076         xid = get_xid();
1077
1078         full_path = build_path_from_dentry(file_dentry(file), page);
1079         if (IS_ERR(full_path)) {
1080                 rc = PTR_ERR(full_path);
1081                 goto rddir2_exit;
1082         }
1083
1084         if (file->private_data == NULL) {
1085                 tlink = cifs_sb_tlink(cifs_sb);
1086                 if (IS_ERR(tlink))
1087                         goto cache_not_found;
1088                 tcon = tlink_tcon(tlink);
1089         } else {
1090                 cifsFile = file->private_data;
1091                 tcon = tlink_tcon(cifsFile->tlink);
1092         }
1093
1094         rc = open_cached_dir(xid, tcon, full_path, cifs_sb, false, &cfid);
1095         cifs_put_tlink(tlink);
1096         if (rc)
1097                 goto cache_not_found;
1098
1099         mutex_lock(&cfid->dirents.de_mutex);
1100         /*
1101          * If this was reading from the start of the directory
1102          * we need to initialize scanning and storing the
1103          * directory content.
1104          */
1105         if (ctx->pos == 0 && cfid->dirents.ctx == NULL) {
1106                 cfid->dirents.ctx = ctx;
1107                 cfid->dirents.pos = 2;
1108         }
1109         /*
1110          * If we already have the entire directory cached then
1111          * we can just serve the cache.
1112          */
1113         if (cfid->dirents.is_valid) {
1114                 if (!dir_emit_dots(file, ctx)) {
1115                         mutex_unlock(&cfid->dirents.de_mutex);
1116                         goto rddir2_exit;
1117                 }
1118                 emit_cached_dirents(&cfid->dirents, ctx);
1119                 mutex_unlock(&cfid->dirents.de_mutex);
1120                 goto rddir2_exit;
1121         }
1122         mutex_unlock(&cfid->dirents.de_mutex);
1123
1124         /* Drop the cache while calling initiate_cifs_search and
1125          * find_cifs_entry in case there will be reconnects during
1126          * query_directory.
1127          */
1128         close_cached_dir(cfid);
1129         cfid = NULL;
1130
1131  cache_not_found:
1132         /*
1133          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
1134          * '..'. Otherwise we won't be able to notify VFS in case of failure.
1135          */
1136         if (file->private_data == NULL) {
1137                 rc = initiate_cifs_search(xid, file, full_path);
1138                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
1139                 if (rc)
1140                         goto rddir2_exit;
1141         }
1142
1143         if (!dir_emit_dots(file, ctx))
1144                 goto rddir2_exit;
1145
1146         /* 1) If search is active,
1147                 is in current search buffer?
1148                 if it before then restart search
1149                 if after then keep searching till find it */
1150         cifsFile = file->private_data;
1151         if (cifsFile->srch_inf.endOfSearch) {
1152                 if (cifsFile->srch_inf.emptyDir) {
1153                         cifs_dbg(FYI, "End of search, empty dir\n");
1154                         rc = 0;
1155                         goto rddir2_exit;
1156                 }
1157         } /* else {
1158                 cifsFile->invalidHandle = true;
1159                 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
1160         } */
1161
1162         tcon = tlink_tcon(cifsFile->tlink);
1163         rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path,
1164                              &current_entry, &num_to_fill);
1165         open_cached_dir(xid, tcon, full_path, cifs_sb, false, &cfid);
1166         if (rc) {
1167                 cifs_dbg(FYI, "fce error %d\n", rc);
1168                 goto rddir2_exit;
1169         } else if (current_entry != NULL) {
1170                 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
1171         } else {
1172                 if (cfid) {
1173                         mutex_lock(&cfid->dirents.de_mutex);
1174                         finished_cached_dirents_count(&cfid->dirents, ctx);
1175                         mutex_unlock(&cfid->dirents.de_mutex);
1176                 }
1177                 cifs_dbg(FYI, "Could not find entry\n");
1178                 goto rddir2_exit;
1179         }
1180         cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
1181                  num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
1182         max_len = tcon->ses->server->ops->calc_smb_size(
1183                         cifsFile->srch_inf.ntwrk_buf_start);
1184         end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
1185
1186         tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
1187         if (tmp_buf == NULL) {
1188                 rc = -ENOMEM;
1189                 goto rddir2_exit;
1190         }
1191
1192         for (i = 0; i < num_to_fill; i++) {
1193                 if (current_entry == NULL) {
1194                         /* evaluate whether this case is an error */
1195                         cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
1196                                  num_to_fill, i);
1197                         break;
1198                 }
1199                 /*
1200                  * if buggy server returns . and .. late do we want to
1201                  * check for that here?
1202                  */
1203                 *tmp_buf = 0;
1204                 rc = cifs_filldir(current_entry, file, ctx,
1205                                   tmp_buf, max_len, cfid);
1206                 if (rc) {
1207                         if (rc > 0)
1208                                 rc = 0;
1209                         break;
1210                 }
1211
1212                 ctx->pos++;
1213                 if (cfid) {
1214                         mutex_lock(&cfid->dirents.de_mutex);
1215                         update_cached_dirents_count(&cfid->dirents, ctx);
1216                         mutex_unlock(&cfid->dirents.de_mutex);
1217                 }
1218
1219                 if (ctx->pos ==
1220                         cifsFile->srch_inf.index_of_last_entry) {
1221                         cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
1222                                  ctx->pos, tmp_buf);
1223                         cifs_save_resume_key(current_entry, cifsFile);
1224                         break;
1225                 }
1226                 current_entry =
1227                         nxt_dir_entry(current_entry, end_of_smb,
1228                                       cifsFile->srch_inf.info_level);
1229         }
1230         kfree(tmp_buf);
1231
1232 rddir2_exit:
1233         if (cfid)
1234                 close_cached_dir(cfid);
1235         free_dentry_path(page);
1236         free_xid(xid);
1237         return rc;
1238 }