fs/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  * Match a reparse point inode if reparse tag and ctime haven't changed.
  60  *
  61  * Windows Server updates ctime of reparse points when their data have changed.
  62  * The server doesn't allow changing reparse tags from existing reparse points,
  63  * though it's worth checking.
  64  */
  65 static inline bool reparse_inode_match(struct inode *inode,
  66                                        struct cifs_fattr *fattr)
  67 {
  68         struct timespec64 ctime = inode_get_ctime(inode);
  69
  70         return (CIFS_I(inode)->cifsAttrs & ATTR_REPARSE) &&
  71                 CIFS_I(inode)->reparse_tag == fattr->cf_cifstag &&
  72                 timespec64_equal(&ctime, &fattr->cf_ctime);
  73 }
  74
  75 /*
  76  * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
  77  *
  78  * Find the dentry that matches "name". If there isn't one, create one. If it's
  79  * a negative dentry or the uniqueid or filetype(mode) changed,
  80  * then drop it and recreate it.
  81  */
  82 static void
  83 cifs_prime_dcache(struct dentry *parent, struct qstr *name,
  84                     struct cifs_fattr *fattr)
  85 {
  86         struct dentry *dentry, *alias;
  87         struct inode *inode;
  88         struct super_block *sb = parent->d_sb;
  89         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
  90         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
  91         int rc;
  92
  93         cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
  94
  95         dentry = d_hash_and_lookup(parent, name);
  96         if (!dentry) {
  97                 /*
  98                  * If we know that the inode will need to be revalidated
  99                  * immediately, then don't create a new dentry for it.
 100                  * We'll end up doing an on the wire call either way and
 101                  * this spares us an invalidation.
 102                  */
 103 retry:
 104                 if ((fattr->cf_cifsattrs & ATTR_REPARSE) ||
 105                     (fattr->cf_flags & CIFS_FATTR_NEED_REVAL))
 106                         return;
 107
 108                 dentry = d_alloc_parallel(parent, name, &wq);
 109         }
 110         if (IS_ERR(dentry))
 111                 return;
 112         if (!d_in_lookup(dentry)) {
 113                 inode = d_inode(dentry);
 114                 if (inode) {
 115                         if (d_mountpoint(dentry)) {
 116                                 dput(dentry);
 117                                 return;
 118                         }
 119                         /*
 120                          * If we're generating inode numbers, then we don't
 121                          * want to clobber the existing one with the one that
 122                          * the readdir code created.
 123                          */
 124                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
 125                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
 126
 127                         /*
 128                          * Update inode in place if both i_ino and i_mode didn't
 129                          * change.
 130                          */
 131                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
 132                                 /*
 133                                  * Query dir responses don't provide enough
 134                                  * information about reparse points other than
 135                                  * their reparse tags.  Save an invalidation by
 136                                  * not clobbering the existing mode, size and
 137                                  * symlink target (if any) when reparse tag and
 138                                  * ctime haven't changed.
 139                                  */
 140                                 rc = 0;
 141                                 if (fattr->cf_cifsattrs & ATTR_REPARSE) {
 142                                         if (likely(reparse_inode_match(inode, fattr))) {
 143                                                 fattr->cf_mode = inode->i_mode;
 144                                                 fattr->cf_eof = CIFS_I(inode)->server_eof;
 145                                                 fattr->cf_symlink_target = NULL;
 146                                         } else {
 147                                                 CIFS_I(inode)->time = 0;
 148                                                 rc = -ESTALE;
 149                                         }
 150                                 }
 151                                 if (!rc && !cifs_fattr_to_inode(inode, fattr)) {
 152                                         dput(dentry);
 153                                         return;
 154                                 }
 155                         }
 156                 }
 157                 d_invalidate(dentry);
 158                 dput(dentry);
 159                 goto retry;
 160         } else {
 161                 inode = cifs_iget(sb, fattr);
 162                 if (!inode)
 163                         inode = ERR_PTR(-ENOMEM);
 164                 alias = d_splice_alias(inode, dentry);
 165                 d_lookup_done(dentry);
 166                 if (alias && !IS_ERR(alias))
 167                         dput(alias);
 168         }
 169         dput(dentry);
 170 }
 171
 172 static void
 173 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 174 {
 175         struct cifs_open_info_data data = {
 176                 .reparse = { .tag = fattr->cf_cifstag, },
 177         };
 178
 179         fattr->cf_uid = cifs_sb->ctx->linux_uid;
 180         fattr->cf_gid = cifs_sb->ctx->linux_gid;
 181
 182         /*
 183          * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they
 184          * are preferred by the Linux client in some cases since, unlike
 185          * the NFS reparse tag (or EAs), they don't require an extra query
 186          * to determine which type of special file they represent.
 187          * TODO: go through all documented  reparse tags to see if we can
 188          * reasonably map some of them to directories vs. files vs. symlinks
 189          */
 190         if ((fattr->cf_cifsattrs & ATTR_REPARSE) &&
 191             cifs_reparse_point_to_fattr(cifs_sb, fattr, &data))
 192                 goto out_reparse;
 193
 194         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 195                 fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode;
 196                 fattr->cf_dtype = DT_DIR;
 197         } else {
 198                 fattr->cf_mode = S_IFREG | cifs_sb->ctx->file_mode;
 199                 fattr->cf_dtype = DT_REG;
 200         }
 201
 202 out_reparse:
 203         /* non-unix readdir doesn't provide nlink */
 204         fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
 205
 206         if (fattr->cf_cifsattrs & ATTR_READONLY)
 207                 fattr->cf_mode &= ~S_IWUGO;
 208
 209         /*
 210          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 211          * mark it for revalidation so that "ls -l" will look right. It might
 212          * be super-slow, but if we don't do this then the ownership of files
 213          * may look wrong since the inodes may not have timed out by the time
 214          * "ls" does a stat() call on them.
 215          */
 216         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
 217             (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
 218                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 219
 220         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 221             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 222                 if (fattr->cf_eof == 0)  {
 223                         fattr->cf_mode &= ~S_IFMT;
 224                         fattr->cf_mode |= S_IFIFO;
 225                         fattr->cf_dtype = DT_FIFO;
 226                 } else {
 227                         /*
 228                          * trying to get the type and mode via SFU can be slow,
 229                          * so just call those regular files for now, and mark
 230                          * for reval
 231                          */
 232                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 233                 }
 234         }
 235 }
 236
 237 /* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
 238 static void
 239 cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
 240                     struct cifs_sb_info *cifs_sb)
 241 {
 242         struct smb2_posix_info_parsed parsed;
 243
 244         posix_info_parse(info, NULL, &parsed);
 245
 246         memset(fattr, 0, sizeof(*fattr));
 247         fattr->cf_uniqueid = le64_to_cpu(info->Inode);
 248         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 249         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 250
 251         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 252         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 253         fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
 254
 255         fattr->cf_nlink = le32_to_cpu(info->HardLinks);
 256         fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
 257
 258         /*
 259          * Since we set the inode type below we need to mask off
 260          * to avoid strange results if bits set above.
 261          * XXX: why not make server&client use the type bits?
 262          */
 263         fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
 264
 265         cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
 266                  le32_to_cpu(info->DeviceId),
 267                  le32_to_cpu(info->ReparseTag),
 268                  le32_to_cpu(info->Mode));
 269
 270         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 271                 fattr->cf_mode |= S_IFDIR;
 272                 fattr->cf_dtype = DT_DIR;
 273         } else {
 274                 /*
 275                  * mark anything that is not a dir as regular
 276                  * file. special files should have the REPARSE
 277                  * attribute and will be marked as needing revaluation
 278                  */
 279                 fattr->cf_mode |= S_IFREG;
 280                 fattr->cf_dtype = DT_REG;
 281         }
 282
 283         sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER);
 284         sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP);
 285 }
 286
 287 static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
 288 {
 289         const FILE_DIRECTORY_INFO *fi = info;
 290
 291         memset(fattr, 0, sizeof(*fattr));
 292         fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
 293         fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
 294         fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
 295         fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
 296         fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);
 297         fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);
 298         fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);
 299 }
 300
 301 void
 302 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 303                        struct cifs_sb_info *cifs_sb)
 304 {
 305         __dir_info_to_fattr(fattr, info);
 306         cifs_fill_common_info(fattr, cifs_sb);
 307 }
 308
 309 static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
 310                                        SEARCH_ID_FULL_DIR_INFO *info,
 311                                        struct cifs_sb_info *cifs_sb)
 312 {
 313         __dir_info_to_fattr(fattr, info);
 314
 315         /* See MS-FSCC 2.4.19 FileIdFullDirectoryInformation */
 316         if (fattr->cf_cifsattrs & ATTR_REPARSE)
 317                 fattr->cf_cifstag = le32_to_cpu(info->EaSize);
 318         cifs_fill_common_info(fattr, cifs_sb);
 319 }
 320
 321 static void
 322 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 323                        struct cifs_sb_info *cifs_sb)
 324 {
 325         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 326
 327         memset(fattr, 0, sizeof(*fattr));
 328         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 329                                             info->LastAccessTime, offset);
 330         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 331                                             info->LastWriteTime, offset);
 332         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 333                                             info->LastWriteTime, offset);
 334
 335         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 336         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 337         fattr->cf_eof = le32_to_cpu(info->DataSize);
 338
 339         cifs_fill_common_info(fattr, cifs_sb);
 340 }
 341
 342 static int
 343 _initiate_cifs_search(const unsigned int xid, struct file *file,
 344                      const char *full_path)
 345 {
 346         __u16 search_flags;
 347         int rc = 0;
 348         struct cifsFileInfo *cifsFile;
 349         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 350         struct tcon_link *tlink = NULL;
 351         struct cifs_tcon *tcon;
 352         struct TCP_Server_Info *server;
 353
 354         if (file->private_data == NULL) {
 355                 tlink = cifs_sb_tlink(cifs_sb);
 356                 if (IS_ERR(tlink))
 357                         return PTR_ERR(tlink);
 358
 359                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 360                 if (cifsFile == NULL) {
 361                         rc = -ENOMEM;
 362                         goto error_exit;
 363                 }
 364                 spin_lock_init(&cifsFile->file_info_lock);
 365                 file->private_data = cifsFile;
 366                 cifsFile->tlink = cifs_get_tlink(tlink);
 367                 tcon = tlink_tcon(tlink);
 368         } else {
 369                 cifsFile = file->private_data;
 370                 tcon = tlink_tcon(cifsFile->tlink);
 371         }
 372
 373         server = tcon->ses->server;
 374
 375         if (!server->ops->query_dir_first) {
 376                 rc = -ENOSYS;
 377                 goto error_exit;
 378         }
 379
 380         cifsFile->invalidHandle = true;
 381         cifsFile->srch_inf.endOfSearch = false;
 382
 383         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
 384
 385 ffirst_retry:
 386         /* test for Unix extensions */
 387         /* but now check for them on the share/mount not on the SMB session */
 388         /* if (cap_unix(tcon->ses) { */
 389         if (tcon->unix_ext)
 390                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 391         else if (tcon->posix_extensions)
 392                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
 393         else if ((tcon->ses->capabilities &
 394                   tcon->ses->server->vals->cap_nt_find) == 0) {
 395                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 396         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 397                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 398         } else /* not srvinos - BB fixme add check for backlevel? */ {
 399                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 400         }
 401
 402         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 403         if (backup_cred(cifs_sb))
 404                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 405
 406         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 407                                           &cifsFile->fid, search_flags,
 408                                           &cifsFile->srch_inf);
 409
 410         if (rc == 0) {
 411                 cifsFile->invalidHandle = false;
 412         } else if ((rc == -EOPNOTSUPP) &&
 413                    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 414                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 415                 goto ffirst_retry;
 416         }
 417 error_exit:
 418         cifs_put_tlink(tlink);
 419         return rc;
 420 }
 421
 422 static int
 423 initiate_cifs_search(const unsigned int xid, struct file *file,
 424                      const char *full_path)
 425 {
 426         int rc, retry_count = 0;
 427
 428         do {
 429                 rc = _initiate_cifs_search(xid, file, full_path);
 430                 /*
 431                  * If we don't have enough credits to start reading the
 432                  * directory just try again after short wait.
 433                  */
 434                 if (rc != -EDEADLK)
 435                         break;
 436
 437                 usleep_range(512, 2048);
 438         } while (retry_count++ < 5);
 439
 440         return rc;
 441 }
 442
 443 /* return length of unicode string in bytes */
 444 static int cifs_unicode_bytelen(const char *str)
 445 {
 446         int len;
 447         const __le16 *ustr = (const __le16 *)str;
 448
 449         for (len = 0; len <= PATH_MAX; len++) {
 450                 if (ustr[len] == 0)
 451                         return len << 1;
 452         }
 453         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
 454         return len << 1;
 455 }
 456
 457 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 458 {
 459         char *new_entry;
 460         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 461
 462         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 463                 FIND_FILE_STANDARD_INFO *pfData;
 464                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 465
 466                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) + 1 +
 467                                 pfData->FileNameLength;
 468         } else {
 469                 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
 470
 471                 if (old_entry + next_offset < old_entry) {
 472                         cifs_dbg(VFS, "Invalid offset %u\n", next_offset);
 473                         return NULL;
 474                 }
 475                 new_entry = old_entry + next_offset;
 476         }
 477         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
 478         /* validate that new_entry is not past end of SMB */
 479         if (new_entry >= end_of_smb) {
 480                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
 481                          new_entry, end_of_smb, old_entry);
 482                 return NULL;
 483         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 484                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) + 1 > end_of_smb))
 485                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 486                    (new_entry + sizeof(FILE_DIRECTORY_INFO) + 1 > end_of_smb)))  {
 487                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
 488                          new_entry, end_of_smb);
 489                 return NULL;
 490         } else
 491                 return new_entry;
 492
 493 }
 494
 495 struct cifs_dirent {
 496         const char      *name;
 497         size_t          namelen;
 498         u32             resume_key;
 499         u64             ino;
 500 };
 501
 502 static void cifs_fill_dirent_posix(struct cifs_dirent *de,
 503                                    const struct smb2_posix_info *info)
 504 {
 505         struct smb2_posix_info_parsed parsed;
 506
 507         /* payload should have already been checked at this point */
 508         if (posix_info_parse(info, NULL, &parsed) < 0) {
 509                 cifs_dbg(VFS, "Invalid POSIX info payload\n");
 510                 return;
 511         }
 512
 513         de->name = parsed.name;
 514         de->namelen = parsed.name_len;
 515         de->resume_key = info->Ignored;
 516         de->ino = le64_to_cpu(info->Inode);
 517 }
 518
 519 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 520                 const FILE_UNIX_INFO *info, bool is_unicode)
 521 {
 522         de->name = &info->FileName[0];
 523         if (is_unicode)
 524                 de->namelen = cifs_unicode_bytelen(de->name);
 525         else
 526                 de->namelen = strnlen(de->name, PATH_MAX);
 527         de->resume_key = info->ResumeKey;
 528         de->ino = le64_to_cpu(info->basic.UniqueId);
 529 }
 530
 531 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 532                 const FILE_DIRECTORY_INFO *info)
 533 {
 534         de->name = &info->FileName[0];
 535         de->namelen = le32_to_cpu(info->FileNameLength);
 536         de->resume_key = info->FileIndex;
 537 }
 538
 539 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 540                 const FILE_FULL_DIRECTORY_INFO *info)
 541 {
 542         de->name = &info->FileName[0];
 543         de->namelen = le32_to_cpu(info->FileNameLength);
 544         de->resume_key = info->FileIndex;
 545 }
 546
 547 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 548                 const SEARCH_ID_FULL_DIR_INFO *info)
 549 {
 550         de->name = &info->FileName[0];
 551         de->namelen = le32_to_cpu(info->FileNameLength);
 552         de->resume_key = info->FileIndex;
 553         de->ino = le64_to_cpu(info->UniqueId);
 554 }
 555
 556 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 557                 const FILE_BOTH_DIRECTORY_INFO *info)
 558 {
 559         de->name = &info->FileName[0];
 560         de->namelen = le32_to_cpu(info->FileNameLength);
 561         de->resume_key = info->FileIndex;
 562 }
 563
 564 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 565                 const FIND_FILE_STANDARD_INFO *info)
 566 {
 567         de->name = &info->FileName[0];
 568         /* one byte length, no endianess conversion */
 569         de->namelen = info->FileNameLength;
 570         de->resume_key = info->ResumeKey;
 571 }
 572
 573 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 574                 u16 level, bool is_unicode)
 575 {
 576         memset(de, 0, sizeof(*de));
 577
 578         switch (level) {
 579         case SMB_FIND_FILE_POSIX_INFO:
 580                 cifs_fill_dirent_posix(de, info);
 581                 break;
 582         case SMB_FIND_FILE_UNIX:
 583                 cifs_fill_dirent_unix(de, info, is_unicode);
 584                 break;
 585         case SMB_FIND_FILE_DIRECTORY_INFO:
 586                 cifs_fill_dirent_dir(de, info);
 587                 break;
 588         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 589                 cifs_fill_dirent_full(de, info);
 590                 break;
 591         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 592                 cifs_fill_dirent_search(de, info);
 593                 break;
 594         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 595                 cifs_fill_dirent_both(de, info);
 596                 break;
 597         case SMB_FIND_FILE_INFO_STANDARD:
 598                 cifs_fill_dirent_std(de, info);
 599                 break;
 600         default:
 601                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
 602                 return -EINVAL;
 603         }
 604
 605         return 0;
 606 }
 607
 608 #define UNICODE_DOT cpu_to_le16(0x2e)
 609
 610 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 611 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 612 {
 613         int rc = 0;
 614
 615         if (!de->name)
 616                 return 0;
 617
 618         if (is_unicode) {
 619                 __le16 *ufilename = (__le16 *)de->name;
 620                 if (de->namelen == 2) {
 621                         /* check for . */
 622                         if (ufilename[0] == UNICODE_DOT)
 623                                 rc = 1;
 624                 } else if (de->namelen == 4) {
 625                         /* check for .. */
 626                         if (ufilename[0] == UNICODE_DOT &&
 627                             ufilename[1] == UNICODE_DOT)
 628                                 rc = 2;
 629                 }
 630         } else /* ASCII */ {
 631                 if (de->namelen == 1) {
 632                         if (de->name[0] == '.')
 633                                 rc = 1;
 634                 } else if (de->namelen == 2) {
 635                         if (de->name[0] == '.' && de->name[1] == '.')
 636                                 rc = 2;
 637                 }
 638         }
 639
 640         return rc;
 641 }
 642
 643 /* Check if directory that we are searching has changed so we can decide
 644    whether we can use the cached search results from the previous search */
 645 static int is_dir_changed(struct file *file)
 646 {
 647         struct inode *inode = file_inode(file);
 648         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 649
 650         if (cifsInfo->time == 0)
 651                 return 1; /* directory was changed, perhaps due to unlink */
 652         else
 653                 return 0;
 654
 655 }
 656
 657 static int cifs_save_resume_key(const char *current_entry,
 658         struct cifsFileInfo *file_info)
 659 {
 660         struct cifs_dirent de;
 661         int rc;
 662
 663         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 664                               file_info->srch_inf.unicode);
 665         if (!rc) {
 666                 file_info->srch_inf.presume_name = de.name;
 667                 file_info->srch_inf.resume_name_len = de.namelen;
 668                 file_info->srch_inf.resume_key = de.resume_key;
 669         }
 670         return rc;
 671 }
 672
 673 /*
 674  * Find the corresponding entry in the search. Note that the SMB server returns
 675  * search entries for . and .. which complicates logic here if we choose to
 676  * parse for them and we do not assume that they are located in the findfirst
 677  * return buffer. We start counting in the buffer with entry 2 and increment for
 678  * every entry (do not increment for . or .. entry).
 679  */
 680 static int
 681 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
 682                 struct file *file, const char *full_path,
 683                 char **current_entry, int *num_to_ret)
 684 {
 685         __u16 search_flags;
 686         int rc = 0;
 687         int pos_in_buf = 0;
 688         loff_t first_entry_in_buffer;
 689         loff_t index_to_find = pos;
 690         struct cifsFileInfo *cfile = file->private_data;
 691         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 692         struct TCP_Server_Info *server = tcon->ses->server;
 693         /* check if index in the buffer */
 694
 695         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 696                 return -ENOSYS;
 697
 698         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 699                 return -ENOENT;
 700
 701         *current_entry = NULL;
 702         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 703                                         cfile->srch_inf.entries_in_buffer;
 704
 705         /*
 706          * If first entry in buf is zero then is first buffer
 707          * in search response data which means it is likely . and ..
 708          * will be in this buffer, although some servers do not return
 709          * . and .. for the root of a drive and for those we need
 710          * to start two entries earlier.
 711          */
 712
 713         dump_cifs_file_struct(file, "In fce ");
 714         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 715              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 716                 /* close and restart search */
 717                 cifs_dbg(FYI, "search backing up - close and restart search\n");
 718                 spin_lock(&cfile->file_info_lock);
 719                 if (server->ops->dir_needs_close(cfile)) {
 720                         cfile->invalidHandle = true;
 721                         spin_unlock(&cfile->file_info_lock);
 722                         if (server->ops->close_dir)
 723                                 server->ops->close_dir(xid, tcon, &cfile->fid);
 724                 } else
 725                         spin_unlock(&cfile->file_info_lock);
 726                 if (cfile->srch_inf.ntwrk_buf_start) {
 727                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
 728                         if (cfile->srch_inf.smallBuf)
 729                                 cifs_small_buf_release(cfile->srch_inf.
 730                                                 ntwrk_buf_start);
 731                         else
 732                                 cifs_buf_release(cfile->srch_inf.
 733                                                 ntwrk_buf_start);
 734                         cfile->srch_inf.ntwrk_buf_start = NULL;
 735                 }
 736                 rc = initiate_cifs_search(xid, file, full_path);
 737                 if (rc) {
 738                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
 739                                  rc);
 740                         return rc;
 741                 }
 742                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 743                 if (cfile->srch_inf.last_entry)
 744                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 745         }
 746
 747         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 748         if (backup_cred(cifs_sb))
 749                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 750
 751         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 752                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 753                 cifs_dbg(FYI, "calling findnext2\n");
 754                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 755                                                  search_flags,
 756                                                  &cfile->srch_inf);
 757                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 758                 if (cfile->srch_inf.last_entry)
 759                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 760                 if (rc)
 761                         return -ENOENT;
 762         }
 763         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 764                 /* we found the buffer that contains the entry */
 765                 /* scan and find it */
 766                 int i;
 767                 char *cur_ent;
 768                 char *end_of_smb;
 769
 770                 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
 771                         cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
 772                         return -EIO;
 773                 }
 774
 775                 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 776                         server->ops->calc_smb_size(
 777                                         cfile->srch_inf.ntwrk_buf_start);
 778
 779                 cur_ent = cfile->srch_inf.srch_entries_start;
 780                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 781                                         - cfile->srch_inf.entries_in_buffer;
 782                 pos_in_buf = index_to_find - first_entry_in_buffer;
 783                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
 784
 785                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 786                         /* go entry by entry figuring out which is first */
 787                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 788                                                 cfile->srch_inf.info_level);
 789                 }
 790                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 791                         /* BB fixme - check if we should flag this error */
 792                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
 793                                  pos_in_buf, index_to_find, rc);
 794                 }
 795                 rc = 0;
 796                 *current_entry = cur_ent;
 797         } else {
 798                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
 799                 return 0;
 800         }
 801
 802         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 803                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
 804                 *num_to_ret = 0;
 805         } else
 806                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 807
 808         return rc;
 809 }
 810
 811 static bool emit_cached_dirents(struct cached_dirents *cde,
 812                                 struct dir_context *ctx)
 813 {
 814         struct cached_dirent *dirent;
 815         bool rc;
 816
 817         list_for_each_entry(dirent, &cde->entries, entry) {
 818                 /*
 819                  * Skip all early entries prior to the current lseek()
 820                  * position.
 821                  */
 822                 if (ctx->pos > dirent->pos)
 823                         continue;
 824                 /*
 825                  * We recorded the current ->pos value for the dirent
 826                  * when we stored it in the cache.
 827                  * However, this sequence of ->pos values may have holes
 828                  * in it, for example dot-dirs returned from the server
 829                  * are suppressed.
 830                  * Handle this bu forcing ctx->pos to be the same as the
 831                  * ->pos of the current dirent we emit from the cache.
 832                  * This means that when we emit these entries from the cache
 833                  * we now emit them with the same ->pos value as in the
 834                  * initial scan.
 835                  */
 836                 ctx->pos = dirent->pos;
 837                 rc = dir_emit(ctx, dirent->name, dirent->namelen,
 838                               dirent->fattr.cf_uniqueid,
 839                               dirent->fattr.cf_dtype);
 840                 if (!rc)
 841                         return rc;
 842                 ctx->pos++;
 843         }
 844         return true;
 845 }
 846
 847 static void update_cached_dirents_count(struct cached_dirents *cde,
 848                                         struct dir_context *ctx)
 849 {
 850         if (cde->ctx != ctx)
 851                 return;
 852         if (cde->is_valid || cde->is_failed)
 853                 return;
 854
 855         cde->pos++;
 856 }
 857
 858 static void finished_cached_dirents_count(struct cached_dirents *cde,
 859                                         struct dir_context *ctx)
 860 {
 861         if (cde->ctx != ctx)
 862                 return;
 863         if (cde->is_valid || cde->is_failed)
 864                 return;
 865         if (ctx->pos != cde->pos)
 866                 return;
 867
 868         cde->is_valid = 1;
 869 }
 870
 871 static void add_cached_dirent(struct cached_dirents *cde,
 872                               struct dir_context *ctx,
 873                               const char *name, int namelen,
 874                               struct cifs_fattr *fattr)
 875 {
 876         struct cached_dirent *de;
 877
 878         if (cde->ctx != ctx)
 879                 return;
 880         if (cde->is_valid || cde->is_failed)
 881                 return;
 882         if (ctx->pos != cde->pos) {
 883                 cde->is_failed = 1;
 884                 return;
 885         }
 886         de = kzalloc(sizeof(*de), GFP_ATOMIC);
 887         if (de == NULL) {
 888                 cde->is_failed = 1;
 889                 return;
 890         }
 891         de->namelen = namelen;
 892         de->name = kstrndup(name, namelen, GFP_ATOMIC);
 893         if (de->name == NULL) {
 894                 kfree(de);
 895                 cde->is_failed = 1;
 896                 return;
 897         }
 898         de->pos = ctx->pos;
 899
 900         memcpy(&de->fattr, fattr, sizeof(struct cifs_fattr));
 901
 902         list_add_tail(&de->entry, &cde->entries);
 903 }
 904
 905 static bool cifs_dir_emit(struct dir_context *ctx,
 906                           const char *name, int namelen,
 907                           struct cifs_fattr *fattr,
 908                           struct cached_fid *cfid)
 909 {
 910         bool rc;
 911         ino_t ino = cifs_uniqueid_to_ino_t(fattr->cf_uniqueid);
 912
 913         rc = dir_emit(ctx, name, namelen, ino, fattr->cf_dtype);
 914         if (!rc)
 915                 return rc;
 916
 917         if (cfid) {
 918                 mutex_lock(&cfid->dirents.de_mutex);
 919                 add_cached_dirent(&cfid->dirents, ctx, name, namelen,
 920                                   fattr);
 921                 mutex_unlock(&cfid->dirents.de_mutex);
 922         }
 923
 924         return rc;
 925 }
 926
 927 static int cifs_filldir(char *find_entry, struct file *file,
 928                         struct dir_context *ctx,
 929                         char *scratch_buf, unsigned int max_len,
 930                         struct cached_fid *cfid)
 931 {
 932         struct cifsFileInfo *file_info = file->private_data;
 933         struct super_block *sb = file_inode(file)->i_sb;
 934         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 935         struct cifs_dirent de = { NULL, };
 936         struct cifs_fattr fattr;
 937         struct qstr name;
 938         int rc = 0;
 939
 940         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 941                               file_info->srch_inf.unicode);
 942         if (rc)
 943                 return rc;
 944
 945         if (de.namelen > max_len) {
 946                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
 947                          de.namelen);
 948                 return -EINVAL;
 949         }
 950
 951         /* skip . and .. since we added them first */
 952         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 953                 return 0;
 954
 955         if (file_info->srch_inf.unicode) {
 956                 struct nls_table *nlt = cifs_sb->local_nls;
 957                 int map_type;
 958
 959                 map_type = cifs_remap(cifs_sb);
 960                 name.name = scratch_buf;
 961                 name.len =
 962                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 963                                         UNICODE_NAME_MAX,
 964                                         min_t(size_t, de.namelen,
 965                                               (size_t)max_len), nlt, map_type);
 966                 name.len -= nls_nullsize(nlt);
 967         } else {
 968                 name.name = de.name;
 969                 name.len = de.namelen;
 970         }
 971
 972         switch (file_info->srch_inf.info_level) {
 973         case SMB_FIND_FILE_POSIX_INFO:
 974                 cifs_posix_to_fattr(&fattr,
 975                                     (struct smb2_posix_info *)find_entry,
 976                                     cifs_sb);
 977                 break;
 978         case SMB_FIND_FILE_UNIX:
 979                 cifs_unix_basic_to_fattr(&fattr,
 980                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 981                                          cifs_sb);
 982                 if (S_ISLNK(fattr.cf_mode))
 983                         fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 984                 break;
 985         case SMB_FIND_FILE_INFO_STANDARD:
 986                 cifs_std_info_to_fattr(&fattr,
 987                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 988                                        cifs_sb);
 989                 break;
 990         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 991                 cifs_fulldir_info_to_fattr(&fattr,
 992                                            (SEARCH_ID_FULL_DIR_INFO *)find_entry,
 993                                            cifs_sb);
 994                 break;
 995         default:
 996                 cifs_dir_info_to_fattr(&fattr,
 997                                        (FILE_DIRECTORY_INFO *)find_entry,
 998                                        cifs_sb);
 999                 break;
1000         }
1001
1002         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
1003                 fattr.cf_uniqueid = de.ino;
1004         } else {
1005                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
1006                 cifs_autodisable_serverino(cifs_sb);
1007         }
1008
1009         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
1010             couldbe_mf_symlink(&fattr))
1011                 /*
1012                  * trying to get the type and mode can be slow,
1013                  * so just call those regular files for now, and mark
1014                  * for reval
1015                  */
1016                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
1017
1018         cifs_prime_dcache(file_dentry(file), &name, &fattr);
1019
1020         return !cifs_dir_emit(ctx, name.name, name.len,
1021                               &fattr, cfid);
1022 }
1023
1024
1025 int cifs_readdir(struct file *file, struct dir_context *ctx)
1026 {
1027         int rc = 0;
1028         unsigned int xid;
1029         int i;
1030         struct tcon_link *tlink = NULL;
1031         struct cifs_tcon *tcon;
1032         struct cifsFileInfo *cifsFile;
1033         char *current_entry;
1034         int num_to_fill = 0;
1035         char *tmp_buf = NULL;
1036         char *end_of_smb;
1037         unsigned int max_len;
1038         const char *full_path;
1039         void *page = alloc_dentry_path();
1040         struct cached_fid *cfid = NULL;
1041         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
1042
1043         xid = get_xid();
1044
1045         full_path = build_path_from_dentry(file_dentry(file), page);
1046         if (IS_ERR(full_path)) {
1047                 rc = PTR_ERR(full_path);
1048                 goto rddir2_exit;
1049         }
1050
1051         if (file->private_data == NULL) {
1052                 tlink = cifs_sb_tlink(cifs_sb);
1053                 if (IS_ERR(tlink))
1054                         goto cache_not_found;
1055                 tcon = tlink_tcon(tlink);
1056         } else {
1057                 cifsFile = file->private_data;
1058                 tcon = tlink_tcon(cifsFile->tlink);
1059         }
1060
1061         rc = open_cached_dir(xid, tcon, full_path, cifs_sb, false, &cfid);
1062         cifs_put_tlink(tlink);
1063         if (rc)
1064                 goto cache_not_found;
1065
1066         mutex_lock(&cfid->dirents.de_mutex);
1067         /*
1068          * If this was reading from the start of the directory
1069          * we need to initialize scanning and storing the
1070          * directory content.
1071          */
1072         if (ctx->pos == 0 && cfid->dirents.ctx == NULL) {
1073                 cfid->dirents.ctx = ctx;
1074                 cfid->dirents.pos = 2;
1075         }
1076         /*
1077          * If we already have the entire directory cached then
1078          * we can just serve the cache.
1079          */
1080         if (cfid->dirents.is_valid) {
1081                 if (!dir_emit_dots(file, ctx)) {
1082                         mutex_unlock(&cfid->dirents.de_mutex);
1083                         goto rddir2_exit;
1084                 }
1085                 emit_cached_dirents(&cfid->dirents, ctx);
1086                 mutex_unlock(&cfid->dirents.de_mutex);
1087                 goto rddir2_exit;
1088         }
1089         mutex_unlock(&cfid->dirents.de_mutex);
1090
1091         /* Drop the cache while calling initiate_cifs_search and
1092          * find_cifs_entry in case there will be reconnects during
1093          * query_directory.
1094          */
1095         close_cached_dir(cfid);
1096         cfid = NULL;
1097
1098  cache_not_found:
1099         /*
1100          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
1101          * '..'. Otherwise we won't be able to notify VFS in case of failure.
1102          */
1103         if (file->private_data == NULL) {
1104                 rc = initiate_cifs_search(xid, file, full_path);
1105                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
1106                 if (rc)
1107                         goto rddir2_exit;
1108         }
1109
1110         if (!dir_emit_dots(file, ctx))
1111                 goto rddir2_exit;
1112
1113         /* 1) If search is active,
1114                 is in current search buffer?
1115                 if it before then restart search
1116                 if after then keep searching till find it */
1117         cifsFile = file->private_data;
1118         if (cifsFile->srch_inf.endOfSearch) {
1119                 if (cifsFile->srch_inf.emptyDir) {
1120                         cifs_dbg(FYI, "End of search, empty dir\n");
1121                         rc = 0;
1122                         goto rddir2_exit;
1123                 }
1124         } /* else {
1125                 cifsFile->invalidHandle = true;
1126                 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
1127         } */
1128
1129         tcon = tlink_tcon(cifsFile->tlink);
1130         rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path,
1131                              &current_entry, &num_to_fill);
1132         open_cached_dir(xid, tcon, full_path, cifs_sb, false, &cfid);
1133         if (rc) {
1134                 cifs_dbg(FYI, "fce error %d\n", rc);
1135                 goto rddir2_exit;
1136         } else if (current_entry != NULL) {
1137                 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
1138         } else {
1139                 if (cfid) {
1140                         mutex_lock(&cfid->dirents.de_mutex);
1141                         finished_cached_dirents_count(&cfid->dirents, ctx);
1142                         mutex_unlock(&cfid->dirents.de_mutex);
1143                 }
1144                 cifs_dbg(FYI, "Could not find entry\n");
1145                 goto rddir2_exit;
1146         }
1147         cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
1148                  num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
1149         max_len = tcon->ses->server->ops->calc_smb_size(
1150                         cifsFile->srch_inf.ntwrk_buf_start);
1151         end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
1152
1153         tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
1154         if (tmp_buf == NULL) {
1155                 rc = -ENOMEM;
1156                 goto rddir2_exit;
1157         }
1158
1159         for (i = 0; i < num_to_fill; i++) {
1160                 if (current_entry == NULL) {
1161                         /* evaluate whether this case is an error */
1162                         cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
1163                                  num_to_fill, i);
1164                         break;
1165                 }
1166                 /*
1167                  * if buggy server returns . and .. late do we want to
1168                  * check for that here?
1169                  */
1170                 *tmp_buf = 0;
1171                 rc = cifs_filldir(current_entry, file, ctx,
1172                                   tmp_buf, max_len, cfid);
1173                 if (rc) {
1174                         if (rc > 0)
1175                                 rc = 0;
1176                         break;
1177                 }
1178
1179                 ctx->pos++;
1180                 if (cfid) {
1181                         mutex_lock(&cfid->dirents.de_mutex);
1182                         update_cached_dirents_count(&cfid->dirents, ctx);
1183                         mutex_unlock(&cfid->dirents.de_mutex);
1184                 }
1185
1186                 if (ctx->pos ==
1187                         cifsFile->srch_inf.index_of_last_entry) {
1188                         cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
1189                                  ctx->pos, tmp_buf);
1190                         cifs_save_resume_key(current_entry, cifsFile);
1191                         break;
1192                 }
1193                 current_entry =
1194                         nxt_dir_entry(current_entry, end_of_smb,
1195                                       cifsFile->srch_inf.info_level);
1196         }
1197         kfree(tmp_buf);
1198
1199 rddir2_exit:
1200         if (cfid)
1201                 close_cached_dir(cfid);
1202         free_dentry_path(page);
1203         free_xid(xid);
1204         return rc;
1205 }