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         int rc = 0;
 223         char *full_path = NULL;
 224         struct cifsFileInfo *cifsFile;
 225         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 226         struct tcon_link *tlink = NULL;
 227         struct cifs_tcon *pTcon;
 228
 229         if (file->private_data == NULL) {
 230                 tlink = cifs_sb_tlink(cifs_sb);
 231                 if (IS_ERR(tlink))
 232                         return PTR_ERR(tlink);
 233
 234                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 235                 if (cifsFile == NULL) {
 236                         rc = -ENOMEM;
 237                         goto error_exit;
 238                 }
 239                 file->private_data = cifsFile;
 240                 cifsFile->tlink = cifs_get_tlink(tlink);
 241                 pTcon = tlink_tcon(tlink);
 242         } else {
 243                 cifsFile = file->private_data;
 244                 pTcon = tlink_tcon(cifsFile->tlink);
 245         }
 246
 247         cifsFile->invalidHandle = true;
 248         cifsFile->srch_inf.endOfSearch = false;
 249
 250         full_path = build_path_from_dentry(file->f_path.dentry);
 251         if (full_path == NULL) {
 252                 rc = -ENOMEM;
 253                 goto error_exit;
 254         }
 255
 256         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 257
 258 ffirst_retry:
 259         /* test for Unix extensions */
 260         /* but now check for them on the share/mount not on the SMB session */
 261 /*      if (pTcon->ses->capabilities & CAP_UNIX) { */
 262         if (pTcon->unix_ext)
 263                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 264         else if ((pTcon->ses->capabilities &
 265                         (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
 266                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 267         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 268                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 269         } else /* not srvinos - BB fixme add check for backlevel? */ {
 270                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 271         }
 272
 273         rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
 274                 &cifsFile->netfid, &cifsFile->srch_inf,
 275                 cifs_sb->mnt_cifs_flags &
 276                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
 277         if (rc == 0)
 278                 cifsFile->invalidHandle = false;
 279         /* BB add following call to handle readdir on new NTFS symlink errors
 280         else if STATUS_STOPPED_ON_SYMLINK
 281                 call get_symlink_reparse_path and retry with new path */
 282         else if ((rc == -EOPNOTSUPP) &&
 283                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 284                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 285                 goto ffirst_retry;
 286         }
 287 error_exit:
 288         kfree(full_path);
 289         cifs_put_tlink(tlink);
 290         return rc;
 291 }
 292
 293 /* return length of unicode string in bytes */
 294 static int cifs_unicode_bytelen(const char *str)
 295 {
 296         int len;
 297         const __le16 *ustr = (const __le16 *)str;
 298
 299         for (len = 0; len <= PATH_MAX; len++) {
 300                 if (ustr[len] == 0)
 301                         return len << 1;
 302         }
 303         cFYI(1, "Unicode string longer than PATH_MAX found");
 304         return len << 1;
 305 }
 306
 307 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 308 {
 309         char *new_entry;
 310         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 311
 312         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 313                 FIND_FILE_STANDARD_INFO *pfData;
 314                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 315
 316                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 317                                 pfData->FileNameLength;
 318         } else
 319                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 320         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 321         /* validate that new_entry is not past end of SMB */
 322         if (new_entry >= end_of_smb) {
 323                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 324                         new_entry, end_of_smb, old_entry);
 325                 return NULL;
 326         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 327                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 328                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 329                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 330                 cERROR(1, "search entry %p extends after end of SMB %p",
 331                         new_entry, end_of_smb);
 332                 return NULL;
 333         } else
 334                 return new_entry;
 335
 336 }
 337
 338 struct cifs_dirent {
 339         const char      *name;
 340         size_t          namelen;
 341         u32             resume_key;
 342         u64             ino;
 343 };
 344
 345 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 346                 const FILE_UNIX_INFO *info, bool is_unicode)
 347 {
 348         de->name = &info->FileName[0];
 349         if (is_unicode)
 350                 de->namelen = cifs_unicode_bytelen(de->name);
 351         else
 352                 de->namelen = strnlen(de->name, PATH_MAX);
 353         de->resume_key = info->ResumeKey;
 354         de->ino = le64_to_cpu(info->basic.UniqueId);
 355 }
 356
 357 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 358                 const FILE_DIRECTORY_INFO *info)
 359 {
 360         de->name = &info->FileName[0];
 361         de->namelen = le32_to_cpu(info->FileNameLength);
 362         de->resume_key = info->FileIndex;
 363 }
 364
 365 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 366                 const FILE_FULL_DIRECTORY_INFO *info)
 367 {
 368         de->name = &info->FileName[0];
 369         de->namelen = le32_to_cpu(info->FileNameLength);
 370         de->resume_key = info->FileIndex;
 371 }
 372
 373 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 374                 const SEARCH_ID_FULL_DIR_INFO *info)
 375 {
 376         de->name = &info->FileName[0];
 377         de->namelen = le32_to_cpu(info->FileNameLength);
 378         de->resume_key = info->FileIndex;
 379         de->ino = le64_to_cpu(info->UniqueId);
 380 }
 381
 382 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 383                 const FILE_BOTH_DIRECTORY_INFO *info)
 384 {
 385         de->name = &info->FileName[0];
 386         de->namelen = le32_to_cpu(info->FileNameLength);
 387         de->resume_key = info->FileIndex;
 388 }
 389
 390 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 391                 const FIND_FILE_STANDARD_INFO *info)
 392 {
 393         de->name = &info->FileName[0];
 394         /* one byte length, no endianess conversion */
 395         de->namelen = info->FileNameLength;
 396         de->resume_key = info->ResumeKey;
 397 }
 398
 399 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 400                 u16 level, bool is_unicode)
 401 {
 402         memset(de, 0, sizeof(*de));
 403
 404         switch (level) {
 405         case SMB_FIND_FILE_UNIX:
 406                 cifs_fill_dirent_unix(de, info, is_unicode);
 407                 break;
 408         case SMB_FIND_FILE_DIRECTORY_INFO:
 409                 cifs_fill_dirent_dir(de, info);
 410                 break;
 411         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 412                 cifs_fill_dirent_full(de, info);
 413                 break;
 414         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 415                 cifs_fill_dirent_search(de, info);
 416                 break;
 417         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 418                 cifs_fill_dirent_both(de, info);
 419                 break;
 420         case SMB_FIND_FILE_INFO_STANDARD:
 421                 cifs_fill_dirent_std(de, info);
 422                 break;
 423         default:
 424                 cFYI(1, "Unknown findfirst level %d", level);
 425                 return -EINVAL;
 426         }
 427
 428         return 0;
 429 }
 430
 431 #define UNICODE_DOT cpu_to_le16(0x2e)
 432
 433 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 434 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 435 {
 436         int rc = 0;
 437
 438         if (!de->name)
 439                 return 0;
 440
 441         if (is_unicode) {
 442                 __le16 *ufilename = (__le16 *)de->name;
 443                 if (de->namelen == 2) {
 444                         /* check for . */
 445                         if (ufilename[0] == UNICODE_DOT)
 446                                 rc = 1;
 447                 } else if (de->namelen == 4) {
 448                         /* check for .. */
 449                         if (ufilename[0] == UNICODE_DOT &&
 450                             ufilename[1] == UNICODE_DOT)
 451                                 rc = 2;
 452                 }
 453         } else /* ASCII */ {
 454                 if (de->namelen == 1) {
 455                         if (de->name[0] == '.')
 456                                 rc = 1;
 457                 } else if (de->namelen == 2) {
 458                         if (de->name[0] == '.' && de->name[1] == '.')
 459                                 rc = 2;
 460                 }
 461         }
 462
 463         return rc;
 464 }
 465
 466 /* Check if directory that we are searching has changed so we can decide
 467    whether we can use the cached search results from the previous search */
 468 static int is_dir_changed(struct file *file)
 469 {
 470         struct inode *inode = file->f_path.dentry->d_inode;
 471         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 472
 473         if (cifsInfo->time == 0)
 474                 return 1; /* directory was changed, perhaps due to unlink */
 475         else
 476                 return 0;
 477
 478 }
 479
 480 static int cifs_save_resume_key(const char *current_entry,
 481         struct cifsFileInfo *file_info)
 482 {
 483         struct cifs_dirent de;
 484         int rc;
 485
 486         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 487                               file_info->srch_inf.unicode);
 488         if (!rc) {
 489                 file_info->srch_inf.presume_name = de.name;
 490                 file_info->srch_inf.resume_name_len = de.namelen;
 491                 file_info->srch_inf.resume_key = de.resume_key;
 492         }
 493         return rc;
 494 }
 495
 496 /* find the corresponding entry in the search */
 497 /* Note that the SMB server returns search entries for . and .. which
 498    complicates logic here if we choose to parse for them and we do not
 499    assume that they are located in the findfirst return buffer.*/
 500 /* We start counting in the buffer with entry 2 and increment for every
 501    entry (do not increment for . or .. entry) */
 502 static int find_cifs_entry(const int xid, struct cifs_tcon *pTcon,
 503         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 504 {
 505         int rc = 0;
 506         int pos_in_buf = 0;
 507         loff_t first_entry_in_buffer;
 508         loff_t index_to_find = file->f_pos;
 509         struct cifsFileInfo *cifsFile = file->private_data;
 510         /* check if index in the buffer */
 511
 512         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 513            (num_to_ret == NULL))
 514                 return -ENOENT;
 515
 516         *ppCurrentEntry = NULL;
 517         first_entry_in_buffer =
 518                 cifsFile->srch_inf.index_of_last_entry -
 519                         cifsFile->srch_inf.entries_in_buffer;
 520
 521         /* if first entry in buf is zero then is first buffer
 522         in search response data which means it is likely . and ..
 523         will be in this buffer, although some servers do not return
 524         . and .. for the root of a drive and for those we need
 525         to start two entries earlier */
 526
 527         dump_cifs_file_struct(file, "In fce ");
 528         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 529              is_dir_changed(file)) ||
 530            (index_to_find < first_entry_in_buffer)) {
 531                 /* close and restart search */
 532                 cFYI(1, "search backing up - close and restart search");
 533                 spin_lock(&cifs_file_list_lock);
 534                 if (!cifsFile->srch_inf.endOfSearch &&
 535                     !cifsFile->invalidHandle) {
 536                         cifsFile->invalidHandle = true;
 537                         spin_unlock(&cifs_file_list_lock);
 538                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 539                 } else
 540                         spin_unlock(&cifs_file_list_lock);
 541                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 542                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 543                         if (cifsFile->srch_inf.smallBuf)
 544                                 cifs_small_buf_release(cifsFile->srch_inf.
 545                                                 ntwrk_buf_start);
 546                         else
 547                                 cifs_buf_release(cifsFile->srch_inf.
 548                                                 ntwrk_buf_start);
 549                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 550                 }
 551                 rc = initiate_cifs_search(xid, file);
 552                 if (rc) {
 553                         cFYI(1, "error %d reinitiating a search on rewind",
 554                                  rc);
 555                         return rc;
 556                 }
 557                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 558                 if (cifsFile->srch_inf.last_entry)
 559                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 560                                                 cifsFile);
 561         }
 562
 563         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 564               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 565                 cFYI(1, "calling findnext2");
 566                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
 567                                   &cifsFile->srch_inf);
 568                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 569                 if (cifsFile->srch_inf.last_entry)
 570                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 571                                                 cifsFile);
 572                 if (rc)
 573                         return -ENOENT;
 574         }
 575         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 576                 /* we found the buffer that contains the entry */
 577                 /* scan and find it */
 578                 int i;
 579                 char *current_entry;
 580                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 581                         smbCalcSize((struct smb_hdr *)
 582                                 cifsFile->srch_inf.ntwrk_buf_start);
 583
 584                 current_entry = cifsFile->srch_inf.srch_entries_start;
 585                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 586                                         - cifsFile->srch_inf.entries_in_buffer;
 587                 pos_in_buf = index_to_find - first_entry_in_buffer;
 588                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 589
 590                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 591                         /* go entry by entry figuring out which is first */
 592                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 593                                                 cifsFile->srch_inf.info_level);
 594                 }
 595                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 596                         /* BB fixme - check if we should flag this error */
 597                         cERROR(1, "reached end of buf searching for pos in buf"
 598                           " %d index to find %lld rc %d",
 599                           pos_in_buf, index_to_find, rc);
 600                 }
 601                 rc = 0;
 602                 *ppCurrentEntry = current_entry;
 603         } else {
 604                 cFYI(1, "index not in buffer - could not findnext into it");
 605                 return 0;
 606         }
 607
 608         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 609                 cFYI(1, "can not return entries pos_in_buf beyond last");
 610                 *num_to_ret = 0;
 611         } else
 612                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 613
 614         return rc;
 615 }
 616
 617 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 618                 void *dirent, char *scratch_buf, unsigned int max_len)
 619 {
 620         struct cifsFileInfo *file_info = file->private_data;
 621         struct super_block *sb = file->f_path.dentry->d_sb;
 622         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 623         struct cifs_dirent de = { NULL, };
 624         struct cifs_fattr fattr;
 625         struct dentry *dentry;
 626         struct qstr name;
 627         int rc = 0;
 628         ino_t ino;
 629
 630         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 631                               file_info->srch_inf.unicode);
 632         if (rc)
 633                 return rc;
 634
 635         if (de.namelen > max_len) {
 636                 cERROR(1, "bad search response length %zd past smb end",
 637                           de.namelen);
 638                 return -EINVAL;
 639         }
 640
 641         /* skip . and .. since we added them first */
 642         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 643                 return 0;
 644
 645         if (file_info->srch_inf.unicode) {
 646                 struct nls_table *nlt = cifs_sb->local_nls;
 647
 648                 name.name = scratch_buf;
 649                 name.len =
 650                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 651                                         UNICODE_NAME_MAX,
 652                                         min_t(size_t, de.namelen,
 653                                               (size_t)max_len), nlt,
 654                                         cifs_sb->mnt_cifs_flags &
 655                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 656                 name.len -= nls_nullsize(nlt);
 657         } else {
 658                 name.name = de.name;
 659                 name.len = de.namelen;
 660         }
 661
 662         switch (file_info->srch_inf.info_level) {
 663         case SMB_FIND_FILE_UNIX:
 664                 cifs_unix_basic_to_fattr(&fattr,
 665                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 666                                          cifs_sb);
 667                 break;
 668         case SMB_FIND_FILE_INFO_STANDARD:
 669                 cifs_std_info_to_fattr(&fattr,
 670                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 671                                        cifs_sb);
 672                 break;
 673         default:
 674                 cifs_dir_info_to_fattr(&fattr,
 675                                        (FILE_DIRECTORY_INFO *)find_entry,
 676                                        cifs_sb);
 677                 break;
 678         }
 679
 680         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 681                 fattr.cf_uniqueid = de.ino;
 682         } else {
 683                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 684                 cifs_autodisable_serverino(cifs_sb);
 685         }
 686
 687         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 688             CIFSCouldBeMFSymlink(&fattr))
 689                 /*
 690                  * trying to get the type and mode can be slow,
 691                  * so just call those regular files for now, and mark
 692                  * for reval
 693                  */
 694                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 695
 696         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 697         dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
 698
 699         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 700                      fattr.cf_dtype);
 701
 702         dput(dentry);
 703         return rc;
 704 }
 705
 706
 707 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 708 {
 709         int rc = 0;
 710         int xid, i;
 711         struct cifs_tcon *pTcon;
 712         struct cifsFileInfo *cifsFile = NULL;
 713         char *current_entry;
 714         int num_to_fill = 0;
 715         char *tmp_buf = NULL;
 716         char *end_of_smb;
 717         unsigned int max_len;
 718
 719         xid = GetXid();
 720
 721         /*
 722          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 723          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 724          */
 725         if (file->private_data == NULL) {
 726                 rc = initiate_cifs_search(xid, file);
 727                 cFYI(1, "initiate cifs search rc %d", rc);
 728                 if (rc)
 729                         goto rddir2_exit;
 730         }
 731
 732         switch ((int) file->f_pos) {
 733         case 0:
 734                 if (filldir(direntry, ".", 1, file->f_pos,
 735                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 736                         cERROR(1, "Filldir for current dir failed");
 737                         rc = -ENOMEM;
 738                         break;
 739                 }
 740                 file->f_pos++;
 741         case 1:
 742                 if (filldir(direntry, "..", 2, file->f_pos,
 743                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 744                         cERROR(1, "Filldir for parent dir failed");
 745                         rc = -ENOMEM;
 746                         break;
 747                 }
 748                 file->f_pos++;
 749         default:
 750                 /* 1) If search is active,
 751                         is in current search buffer?
 752                         if it before then restart search
 753                         if after then keep searching till find it */
 754
 755                 if (file->private_data == NULL) {
 756                         rc = -EINVAL;
 757                         FreeXid(xid);
 758                         return rc;
 759                 }
 760                 cifsFile = file->private_data;
 761                 if (cifsFile->srch_inf.endOfSearch) {
 762                         if (cifsFile->srch_inf.emptyDir) {
 763                                 cFYI(1, "End of search, empty dir");
 764                                 rc = 0;
 765                                 break;
 766                         }
 767                 } /* else {
 768                         cifsFile->invalidHandle = true;
 769                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 770                 } */
 771
 772                 pTcon = tlink_tcon(cifsFile->tlink);
 773                 rc = find_cifs_entry(xid, pTcon, file,
 774                                 &current_entry, &num_to_fill);
 775                 if (rc) {
 776                         cFYI(1, "fce error %d", rc);
 777                         goto rddir2_exit;
 778                 } else if (current_entry != NULL) {
 779                         cFYI(1, "entry %lld found", file->f_pos);
 780                 } else {
 781                         cFYI(1, "could not find entry");
 782                         goto rddir2_exit;
 783                 }
 784                 cFYI(1, "loop through %d times filling dir for net buf %p",
 785                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 786                 max_len = smbCalcSize((struct smb_hdr *)
 787                                 cifsFile->srch_inf.ntwrk_buf_start);
 788                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 789
 790                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 791                 if (tmp_buf == NULL) {
 792                         rc = -ENOMEM;
 793                         break;
 794                 }
 795
 796                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 797                         if (current_entry == NULL) {
 798                                 /* evaluate whether this case is an error */
 799                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 800                                           num_to_fill, i);
 801                                 break;
 802                         }
 803                         /* if buggy server returns . and .. late do
 804                         we want to check for that here? */
 805                         rc = cifs_filldir(current_entry, file,
 806                                         filldir, direntry, tmp_buf, max_len);
 807                         if (rc == -EOVERFLOW) {
 808                                 rc = 0;
 809                                 break;
 810                         }
 811
 812                         file->f_pos++;
 813                         if (file->f_pos ==
 814                                 cifsFile->srch_inf.index_of_last_entry) {
 815                                 cFYI(1, "last entry in buf at pos %lld %s",
 816                                         file->f_pos, tmp_buf);
 817                                 cifs_save_resume_key(current_entry, cifsFile);
 818                                 break;
 819                         } else
 820                                 current_entry =
 821                                         nxt_dir_entry(current_entry, end_of_smb,
 822                                                 cifsFile->srch_inf.info_level);
 823                 }
 824                 kfree(tmp_buf);
 825                 break;
 826         } /* end switch */
 827
 828 rddir2_exit:
 829         FreeXid(xid);
 830         return rc;
 831 }