fs/cifs/readdir.c

   1 /*
   2  *   fs/cifs/readdir.c
   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  *   This library is free software; you can redistribute it and/or modify
  11  *   it under the terms of the GNU Lesser General Public License as published
  12  *   by the Free Software Foundation; either version 2.1 of the License, or
  13  *   (at your option) any later version.
  14  *
  15  *   This library is distributed in the hope that it will be useful,
  16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  18  *   the GNU Lesser General Public License for more details.
  19  *
  20  *   You should have received a copy of the GNU Lesser General Public License
  21  *   along with this library; if not, write to the Free Software
  22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24 #include <linux/fs.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/slab.h>
  27 #include <linux/stat.h>
  28 #include "cifspdu.h"
  29 #include "cifsglob.h"
  30 #include "cifsproto.h"
  31 #include "cifs_unicode.h"
  32 #include "cifs_debug.h"
  33 #include "cifs_fs_sb.h"
  34 #include "cifsfs.h"
  35
  36 /*
  37  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  38  * characters alloc more to account for such multibyte target UTF-8
  39  * characters.
  40  */
  41 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  42
  43 #ifdef CONFIG_CIFS_DEBUG2
  44 static void dump_cifs_file_struct(struct file *file, char *label)
  45 {
  46         struct cifsFileInfo *cf;
  47
  48         if (file) {
  49                 cf = file->private_data;
  50                 if (cf == NULL) {
  51                         cFYI(1, "empty cifs private file data");
  52                         return;
  53                 }
  54                 if (cf->invalidHandle)
  55                         cFYI(1, "invalid handle");
  56                 if (cf->srch_inf.endOfSearch)
  57                         cFYI(1, "end of search");
  58                 if (cf->srch_inf.emptyDir)
  59                         cFYI(1, "empty dir");
  60         }
  61 }
  62 #else
  63 static inline void dump_cifs_file_struct(struct file *file, char *label)
  64 {
  65 }
  66 #endif /* DEBUG2 */
  67
  68 /*
  69  * Find the dentry that matches "name". If there isn't one, create one. If it's
  70  * a negative dentry or the uniqueid changed, then drop it and recreate it.
  71  */
  72 static struct dentry *
  73 cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
  74                     struct cifs_fattr *fattr)
  75 {
  76         struct dentry *dentry, *alias;
  77         struct inode *inode;
  78         struct super_block *sb = parent->d_inode->i_sb;
  79
  80         cFYI(1, "For %s", name->name);
  81
  82         if (parent->d_op && parent->d_op->d_hash)
  83                 parent->d_op->d_hash(parent, parent->d_inode, name);
  84         else
  85                 name->hash = full_name_hash(name->name, name->len);
  86
  87         dentry = d_lookup(parent, name);
  88         if (dentry) {
  89                 /* FIXME: check for inode number changes? */
  90                 if (dentry->d_inode != NULL)
  91                         return dentry;
  92                 d_drop(dentry);
  93                 dput(dentry);
  94         }
  95
  96         dentry = d_alloc(parent, name);
  97         if (dentry == NULL)
  98                 return NULL;
  99
 100         inode = cifs_iget(sb, fattr);
 101         if (!inode) {
 102                 dput(dentry);
 103                 return NULL;
 104         }
 105
 106         alias = d_materialise_unique(dentry, inode);
 107         if (alias != NULL) {
 108                 dput(dentry);
 109                 if (IS_ERR(alias))
 110                         return NULL;
 111                 dentry = alias;
 112         }
 113
 114         return dentry;
 115 }
 116
 117 static void
 118 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 119 {
 120         fattr->cf_uid = cifs_sb->mnt_uid;
 121         fattr->cf_gid = cifs_sb->mnt_gid;
 122
 123         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 124                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 125                 fattr->cf_dtype = DT_DIR;
 126         } else {
 127                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 128                 fattr->cf_dtype = DT_REG;
 129         }
 130
 131         if (fattr->cf_cifsattrs & ATTR_READONLY)
 132                 fattr->cf_mode &= ~S_IWUGO;
 133
 134         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 135             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 136                 if (fattr->cf_eof == 0)  {
 137                         fattr->cf_mode &= ~S_IFMT;
 138                         fattr->cf_mode |= S_IFIFO;
 139                         fattr->cf_dtype = DT_FIFO;
 140                 } else {
 141                         /*
 142                          * trying to get the type and mode via SFU can be slow,
 143                          * so just call those regular files for now, and mark
 144                          * for reval
 145                          */
 146                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 147                 }
 148         }
 149 }
 150
 151 static void
 152 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 153                        struct cifs_sb_info *cifs_sb)
 154 {
 155         memset(fattr, 0, sizeof(*fattr));
 156         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 157         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 158         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 159         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 160         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 161         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 162         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 163
 164         cifs_fill_common_info(fattr, cifs_sb);
 165 }
 166
 167 static void
 168 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 169                        struct cifs_sb_info *cifs_sb)
 170 {
 171         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 172
 173         memset(fattr, 0, sizeof(*fattr));
 174         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 175                                             info->LastAccessTime, offset);
 176         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 177                                             info->LastWriteTime, offset);
 178         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 179                                             info->LastWriteTime, offset);
 180
 181         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 182         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 183         fattr->cf_eof = le32_to_cpu(info->DataSize);
 184
 185         cifs_fill_common_info(fattr, cifs_sb);
 186 }
 187
 188 /* BB eventually need to add the following helper function to
 189       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 190       we try to do FindFirst on (NTFS) directory symlinks */
 191 /*
 192 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 193                              int xid)
 194 {
 195         __u16 fid;
 196         int len;
 197         int oplock = 0;
 198         int rc;
 199         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 200         char *tmpbuffer;
 201
 202         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 203                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 204                         cifs_sb->local_nls,
 205                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 206         if (!rc) {
 207                 tmpbuffer = kmalloc(maxpath);
 208                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 209                                 tmpbuffer,
 210                                 maxpath -1,
 211                                 fid,
 212                                 cifs_sb->local_nls);
 213                 if (CIFSSMBClose(xid, ptcon, fid)) {
 214                         cFYI(1, "Error closing temporary reparsepoint open");
 215                 }
 216         }
 217 }
 218  */
 219
 220 static int initiate_cifs_search(const int xid, struct file *file)
 221 {
 222         __u16 search_flags;
 223         int rc = 0;
 224         char *full_path = NULL;
 225         struct cifsFileInfo *cifsFile;
 226         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 227         struct tcon_link *tlink = NULL;
 228         struct cifs_tcon *pTcon;
 229
 230         if (file->private_data == NULL) {
 231                 tlink = cifs_sb_tlink(cifs_sb);
 232                 if (IS_ERR(tlink))
 233                         return PTR_ERR(tlink);
 234
 235                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 236                 if (cifsFile == NULL) {
 237                         rc = -ENOMEM;
 238                         goto error_exit;
 239                 }
 240                 file->private_data = cifsFile;
 241                 cifsFile->tlink = cifs_get_tlink(tlink);
 242                 pTcon = tlink_tcon(tlink);
 243         } else {
 244                 cifsFile = file->private_data;
 245                 pTcon = tlink_tcon(cifsFile->tlink);
 246         }
 247
 248         cifsFile->invalidHandle = true;
 249         cifsFile->srch_inf.endOfSearch = false;
 250
 251         full_path = build_path_from_dentry(file->f_path.dentry);
 252         if (full_path == NULL) {
 253                 rc = -ENOMEM;
 254                 goto error_exit;
 255         }
 256
 257         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 258
 259 ffirst_retry:
 260         /* test for Unix extensions */
 261         /* but now check for them on the share/mount not on the SMB session */
 262 /*      if (pTcon->ses->capabilities & CAP_UNIX) { */
 263         if (pTcon->unix_ext)
 264                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 265         else if ((pTcon->ses->capabilities &
 266                         (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
 267                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 268         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 269                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 270         } else /* not srvinos - BB fixme add check for backlevel? */ {
 271                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 272         }
 273
 274         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 275         if (backup_cred(cifs_sb))
 276                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 277
 278         rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
 279                 &cifsFile->netfid, search_flags, &cifsFile->srch_inf,
 280                 cifs_sb->mnt_cifs_flags &
 281                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
 282         if (rc == 0)
 283                 cifsFile->invalidHandle = false;
 284         /* BB add following call to handle readdir on new NTFS symlink errors
 285         else if STATUS_STOPPED_ON_SYMLINK
 286                 call get_symlink_reparse_path and retry with new path */
 287         else if ((rc == -EOPNOTSUPP) &&
 288                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 289                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 290                 goto ffirst_retry;
 291         }
 292 error_exit:
 293         kfree(full_path);
 294         cifs_put_tlink(tlink);
 295         return rc;
 296 }
 297
 298 /* return length of unicode string in bytes */
 299 static int cifs_unicode_bytelen(const char *str)
 300 {
 301         int len;
 302         const __le16 *ustr = (const __le16 *)str;
 303
 304         for (len = 0; len <= PATH_MAX; len++) {
 305                 if (ustr[len] == 0)
 306                         return len << 1;
 307         }
 308         cFYI(1, "Unicode string longer than PATH_MAX found");
 309         return len << 1;
 310 }
 311
 312 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 313 {
 314         char *new_entry;
 315         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 316
 317         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 318                 FIND_FILE_STANDARD_INFO *pfData;
 319                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 320
 321                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 322                                 pfData->FileNameLength;
 323         } else
 324                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 325         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 326         /* validate that new_entry is not past end of SMB */
 327         if (new_entry >= end_of_smb) {
 328                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 329                         new_entry, end_of_smb, old_entry);
 330                 return NULL;
 331         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 332                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 333                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 334                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 335                 cERROR(1, "search entry %p extends after end of SMB %p",
 336                         new_entry, end_of_smb);
 337                 return NULL;
 338         } else
 339                 return new_entry;
 340
 341 }
 342
 343 struct cifs_dirent {
 344         const char      *name;
 345         size_t          namelen;
 346         u32             resume_key;
 347         u64             ino;
 348 };
 349
 350 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 351                 const FILE_UNIX_INFO *info, bool is_unicode)
 352 {
 353         de->name = &info->FileName[0];
 354         if (is_unicode)
 355                 de->namelen = cifs_unicode_bytelen(de->name);
 356         else
 357                 de->namelen = strnlen(de->name, PATH_MAX);
 358         de->resume_key = info->ResumeKey;
 359         de->ino = le64_to_cpu(info->basic.UniqueId);
 360 }
 361
 362 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 363                 const FILE_DIRECTORY_INFO *info)
 364 {
 365         de->name = &info->FileName[0];
 366         de->namelen = le32_to_cpu(info->FileNameLength);
 367         de->resume_key = info->FileIndex;
 368 }
 369
 370 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 371                 const FILE_FULL_DIRECTORY_INFO *info)
 372 {
 373         de->name = &info->FileName[0];
 374         de->namelen = le32_to_cpu(info->FileNameLength);
 375         de->resume_key = info->FileIndex;
 376 }
 377
 378 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 379                 const SEARCH_ID_FULL_DIR_INFO *info)
 380 {
 381         de->name = &info->FileName[0];
 382         de->namelen = le32_to_cpu(info->FileNameLength);
 383         de->resume_key = info->FileIndex;
 384         de->ino = le64_to_cpu(info->UniqueId);
 385 }
 386
 387 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 388                 const FILE_BOTH_DIRECTORY_INFO *info)
 389 {
 390         de->name = &info->FileName[0];
 391         de->namelen = le32_to_cpu(info->FileNameLength);
 392         de->resume_key = info->FileIndex;
 393 }
 394
 395 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 396                 const FIND_FILE_STANDARD_INFO *info)
 397 {
 398         de->name = &info->FileName[0];
 399         /* one byte length, no endianess conversion */
 400         de->namelen = info->FileNameLength;
 401         de->resume_key = info->ResumeKey;
 402 }
 403
 404 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 405                 u16 level, bool is_unicode)
 406 {
 407         memset(de, 0, sizeof(*de));
 408
 409         switch (level) {
 410         case SMB_FIND_FILE_UNIX:
 411                 cifs_fill_dirent_unix(de, info, is_unicode);
 412                 break;
 413         case SMB_FIND_FILE_DIRECTORY_INFO:
 414                 cifs_fill_dirent_dir(de, info);
 415                 break;
 416         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 417                 cifs_fill_dirent_full(de, info);
 418                 break;
 419         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 420                 cifs_fill_dirent_search(de, info);
 421                 break;
 422         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 423                 cifs_fill_dirent_both(de, info);
 424                 break;
 425         case SMB_FIND_FILE_INFO_STANDARD:
 426                 cifs_fill_dirent_std(de, info);
 427                 break;
 428         default:
 429                 cFYI(1, "Unknown findfirst level %d", level);
 430                 return -EINVAL;
 431         }
 432
 433         return 0;
 434 }
 435
 436 #define UNICODE_DOT cpu_to_le16(0x2e)
 437
 438 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 439 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 440 {
 441         int rc = 0;
 442
 443         if (!de->name)
 444                 return 0;
 445
 446         if (is_unicode) {
 447                 __le16 *ufilename = (__le16 *)de->name;
 448                 if (de->namelen == 2) {
 449                         /* check for . */
 450                         if (ufilename[0] == UNICODE_DOT)
 451                                 rc = 1;
 452                 } else if (de->namelen == 4) {
 453                         /* check for .. */
 454                         if (ufilename[0] == UNICODE_DOT &&
 455                             ufilename[1] == UNICODE_DOT)
 456                                 rc = 2;
 457                 }
 458         } else /* ASCII */ {
 459                 if (de->namelen == 1) {
 460                         if (de->name[0] == '.')
 461                                 rc = 1;
 462                 } else if (de->namelen == 2) {
 463                         if (de->name[0] == '.' && de->name[1] == '.')
 464                                 rc = 2;
 465                 }
 466         }
 467
 468         return rc;
 469 }
 470
 471 /* Check if directory that we are searching has changed so we can decide
 472    whether we can use the cached search results from the previous search */
 473 static int is_dir_changed(struct file *file)
 474 {
 475         struct inode *inode = file->f_path.dentry->d_inode;
 476         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 477
 478         if (cifsInfo->time == 0)
 479                 return 1; /* directory was changed, perhaps due to unlink */
 480         else
 481                 return 0;
 482
 483 }
 484
 485 static int cifs_save_resume_key(const char *current_entry,
 486         struct cifsFileInfo *file_info)
 487 {
 488         struct cifs_dirent de;
 489         int rc;
 490
 491         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 492                               file_info->srch_inf.unicode);
 493         if (!rc) {
 494                 file_info->srch_inf.presume_name = de.name;
 495                 file_info->srch_inf.resume_name_len = de.namelen;
 496                 file_info->srch_inf.resume_key = de.resume_key;
 497         }
 498         return rc;
 499 }
 500
 501 /* find the corresponding entry in the search */
 502 /* Note that the SMB server returns search entries for . and .. which
 503    complicates logic here if we choose to parse for them and we do not
 504    assume that they are located in the findfirst return buffer.*/
 505 /* We start counting in the buffer with entry 2 and increment for every
 506    entry (do not increment for . or .. entry) */
 507 static int find_cifs_entry(const int xid, struct cifs_tcon *pTcon,
 508         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 509 {
 510         __u16 search_flags;
 511         int rc = 0;
 512         int pos_in_buf = 0;
 513         loff_t first_entry_in_buffer;
 514         loff_t index_to_find = file->f_pos;
 515         struct cifsFileInfo *cifsFile = file->private_data;
 516         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 517         /* check if index in the buffer */
 518
 519         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 520            (num_to_ret == NULL))
 521                 return -ENOENT;
 522
 523         *ppCurrentEntry = NULL;
 524         first_entry_in_buffer =
 525                 cifsFile->srch_inf.index_of_last_entry -
 526                         cifsFile->srch_inf.entries_in_buffer;
 527
 528         /* if first entry in buf is zero then is first buffer
 529         in search response data which means it is likely . and ..
 530         will be in this buffer, although some servers do not return
 531         . and .. for the root of a drive and for those we need
 532         to start two entries earlier */
 533
 534         dump_cifs_file_struct(file, "In fce ");
 535         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 536              is_dir_changed(file)) ||
 537            (index_to_find < first_entry_in_buffer)) {
 538                 /* close and restart search */
 539                 cFYI(1, "search backing up - close and restart search");
 540                 spin_lock(&cifs_file_list_lock);
 541                 if (!cifsFile->srch_inf.endOfSearch &&
 542                     !cifsFile->invalidHandle) {
 543                         cifsFile->invalidHandle = true;
 544                         spin_unlock(&cifs_file_list_lock);
 545                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 546                 } else
 547                         spin_unlock(&cifs_file_list_lock);
 548                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 549                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 550                         if (cifsFile->srch_inf.smallBuf)
 551                                 cifs_small_buf_release(cifsFile->srch_inf.
 552                                                 ntwrk_buf_start);
 553                         else
 554                                 cifs_buf_release(cifsFile->srch_inf.
 555                                                 ntwrk_buf_start);
 556                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 557                 }
 558                 rc = initiate_cifs_search(xid, file);
 559                 if (rc) {
 560                         cFYI(1, "error %d reinitiating a search on rewind",
 561                                  rc);
 562                         return rc;
 563                 }
 564                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 565                 if (cifsFile->srch_inf.last_entry)
 566                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 567                                                 cifsFile);
 568         }
 569
 570         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 571         if (backup_cred(cifs_sb))
 572                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 573
 574         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 575               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 576                 cFYI(1, "calling findnext2");
 577                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid, search_flags,
 578                                   &cifsFile->srch_inf);
 579                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 580                 if (cifsFile->srch_inf.last_entry)
 581                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 582                                                 cifsFile);
 583                 if (rc)
 584                         return -ENOENT;
 585         }
 586         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 587                 /* we found the buffer that contains the entry */
 588                 /* scan and find it */
 589                 int i;
 590                 char *current_entry;
 591                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 592                         smbCalcSize((struct smb_hdr *)
 593                                 cifsFile->srch_inf.ntwrk_buf_start);
 594
 595                 current_entry = cifsFile->srch_inf.srch_entries_start;
 596                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 597                                         - cifsFile->srch_inf.entries_in_buffer;
 598                 pos_in_buf = index_to_find - first_entry_in_buffer;
 599                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 600
 601                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 602                         /* go entry by entry figuring out which is first */
 603                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 604                                                 cifsFile->srch_inf.info_level);
 605                 }
 606                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 607                         /* BB fixme - check if we should flag this error */
 608                         cERROR(1, "reached end of buf searching for pos in buf"
 609                           " %d index to find %lld rc %d",
 610                           pos_in_buf, index_to_find, rc);
 611                 }
 612                 rc = 0;
 613                 *ppCurrentEntry = current_entry;
 614         } else {
 615                 cFYI(1, "index not in buffer - could not findnext into it");
 616                 return 0;
 617         }
 618
 619         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 620                 cFYI(1, "can not return entries pos_in_buf beyond last");
 621                 *num_to_ret = 0;
 622         } else
 623                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 624
 625         return rc;
 626 }
 627
 628 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 629                 void *dirent, char *scratch_buf, unsigned int max_len)
 630 {
 631         struct cifsFileInfo *file_info = file->private_data;
 632         struct super_block *sb = file->f_path.dentry->d_sb;
 633         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 634         struct cifs_dirent de = { NULL, };
 635         struct cifs_fattr fattr;
 636         struct dentry *dentry;
 637         struct qstr name;
 638         int rc = 0;
 639         ino_t ino;
 640
 641         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 642                               file_info->srch_inf.unicode);
 643         if (rc)
 644                 return rc;
 645
 646         if (de.namelen > max_len) {
 647                 cERROR(1, "bad search response length %zd past smb end",
 648                           de.namelen);
 649                 return -EINVAL;
 650         }
 651
 652         /* skip . and .. since we added them first */
 653         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 654                 return 0;
 655
 656         if (file_info->srch_inf.unicode) {
 657                 struct nls_table *nlt = cifs_sb->local_nls;
 658
 659                 name.name = scratch_buf;
 660                 name.len =
 661                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 662                                         UNICODE_NAME_MAX,
 663                                         min_t(size_t, de.namelen,
 664                                               (size_t)max_len), nlt,
 665                                         cifs_sb->mnt_cifs_flags &
 666                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 667                 name.len -= nls_nullsize(nlt);
 668         } else {
 669                 name.name = de.name;
 670                 name.len = de.namelen;
 671         }
 672
 673         switch (file_info->srch_inf.info_level) {
 674         case SMB_FIND_FILE_UNIX:
 675                 cifs_unix_basic_to_fattr(&fattr,
 676                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 677                                          cifs_sb);
 678                 break;
 679         case SMB_FIND_FILE_INFO_STANDARD:
 680                 cifs_std_info_to_fattr(&fattr,
 681                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 682                                        cifs_sb);
 683                 break;
 684         default:
 685                 cifs_dir_info_to_fattr(&fattr,
 686                                        (FILE_DIRECTORY_INFO *)find_entry,
 687                                        cifs_sb);
 688                 break;
 689         }
 690
 691         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 692                 fattr.cf_uniqueid = de.ino;
 693         } else {
 694                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 695                 cifs_autodisable_serverino(cifs_sb);
 696         }
 697
 698         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 699             CIFSCouldBeMFSymlink(&fattr))
 700                 /*
 701                  * trying to get the type and mode can be slow,
 702                  * so just call those regular files for now, and mark
 703                  * for reval
 704                  */
 705                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 706
 707         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 708         dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
 709
 710         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 711                      fattr.cf_dtype);
 712
 713         dput(dentry);
 714         return rc;
 715 }
 716
 717
 718 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 719 {
 720         int rc = 0;
 721         int xid, i;
 722         struct cifs_tcon *pTcon;
 723         struct cifsFileInfo *cifsFile = NULL;
 724         char *current_entry;
 725         int num_to_fill = 0;
 726         char *tmp_buf = NULL;
 727         char *end_of_smb;
 728         unsigned int max_len;
 729
 730         xid = GetXid();
 731
 732         /*
 733          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 734          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 735          */
 736         if (file->private_data == NULL) {
 737                 rc = initiate_cifs_search(xid, file);
 738                 cFYI(1, "initiate cifs search rc %d", rc);
 739                 if (rc)
 740                         goto rddir2_exit;
 741         }
 742
 743         switch ((int) file->f_pos) {
 744         case 0:
 745                 if (filldir(direntry, ".", 1, file->f_pos,
 746                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 747                         cERROR(1, "Filldir for current dir failed");
 748                         rc = -ENOMEM;
 749                         break;
 750                 }
 751                 file->f_pos++;
 752         case 1:
 753                 if (filldir(direntry, "..", 2, file->f_pos,
 754                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 755                         cERROR(1, "Filldir for parent dir failed");
 756                         rc = -ENOMEM;
 757                         break;
 758                 }
 759                 file->f_pos++;
 760         default:
 761                 /* 1) If search is active,
 762                         is in current search buffer?
 763                         if it before then restart search
 764                         if after then keep searching till find it */
 765
 766                 if (file->private_data == NULL) {
 767                         rc = -EINVAL;
 768                         FreeXid(xid);
 769                         return rc;
 770                 }
 771                 cifsFile = file->private_data;
 772                 if (cifsFile->srch_inf.endOfSearch) {
 773                         if (cifsFile->srch_inf.emptyDir) {
 774                                 cFYI(1, "End of search, empty dir");
 775                                 rc = 0;
 776                                 break;
 777                         }
 778                 } /* else {
 779                         cifsFile->invalidHandle = true;
 780                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 781                 } */
 782
 783                 pTcon = tlink_tcon(cifsFile->tlink);
 784                 rc = find_cifs_entry(xid, pTcon, file,
 785                                 &current_entry, &num_to_fill);
 786                 if (rc) {
 787                         cFYI(1, "fce error %d", rc);
 788                         goto rddir2_exit;
 789                 } else if (current_entry != NULL) {
 790                         cFYI(1, "entry %lld found", file->f_pos);
 791                 } else {
 792                         cFYI(1, "could not find entry");
 793                         goto rddir2_exit;
 794                 }
 795                 cFYI(1, "loop through %d times filling dir for net buf %p",
 796                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 797                 max_len = smbCalcSize((struct smb_hdr *)
 798                                 cifsFile->srch_inf.ntwrk_buf_start);
 799                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 800
 801                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 802                 if (tmp_buf == NULL) {
 803                         rc = -ENOMEM;
 804                         break;
 805                 }
 806
 807                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 808                         if (current_entry == NULL) {
 809                                 /* evaluate whether this case is an error */
 810                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 811                                           num_to_fill, i);
 812                                 break;
 813                         }
 814                         /* if buggy server returns . and .. late do
 815                         we want to check for that here? */
 816                         rc = cifs_filldir(current_entry, file,
 817                                         filldir, direntry, tmp_buf, max_len);
 818                         if (rc == -EOVERFLOW) {
 819                                 rc = 0;
 820                                 break;
 821                         }
 822
 823                         file->f_pos++;
 824                         if (file->f_pos ==
 825                                 cifsFile->srch_inf.index_of_last_entry) {
 826                                 cFYI(1, "last entry in buf at pos %lld %s",
 827                                         file->f_pos, tmp_buf);
 828                                 cifs_save_resume_key(current_entry, cifsFile);
 829                                 break;
 830                         } else
 831                                 current_entry =
 832                                         nxt_dir_entry(current_entry, end_of_smb,
 833                                                 cifsFile->srch_inf.info_level);
 834                 }
 835                 kfree(tmp_buf);
 836                 break;
 837         } /* end switch */
 838
 839 rddir2_exit:
 840         FreeXid(xid);
 841         return rc;
 842 }