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  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23 #include <linux/fs.h>
  24 #include <linux/pagemap.h>
  25 #include <linux/stat.h>
  26 #include "cifspdu.h"
  27 #include "cifsglob.h"
  28 #include "cifsproto.h"
  29 #include "cifs_unicode.h"
  30 #include "cifs_debug.h"
  31 #include "cifs_fs_sb.h"
  32 #include "cifsfs.h"
  33
  34 /*
  35  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  36  * characters alloc more to account for such multibyte target UTF-8
  37  * characters.
  38  */
  39 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  40
  41 #ifdef CONFIG_CIFS_DEBUG2
  42 static void dump_cifs_file_struct(struct file *file, char *label)
  43 {
  44         struct cifsFileInfo *cf;
  45
  46         if (file) {
  47                 cf = file->private_data;
  48                 if (cf == NULL) {
  49                         cFYI(1, ("empty cifs private file data"));
  50                         return;
  51                 }
  52                 if (cf->invalidHandle)
  53                         cFYI(1, ("invalid handle"));
  54                 if (cf->srch_inf.endOfSearch)
  55                         cFYI(1, ("end of search"));
  56                 if (cf->srch_inf.emptyDir)
  57                         cFYI(1, ("empty dir"));
  58         }
  59 }
  60 #else
  61 static inline void dump_cifs_file_struct(struct file *file, char *label)
  62 {
  63 }
  64 #endif /* DEBUG2 */
  65
  66 /*
  67  * Find the dentry that matches "name". If there isn't one, create one. If it's
  68  * a negative dentry or the uniqueid changed, then drop it and recreate it.
  69  */
  70 static struct dentry *
  71 cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
  72                     struct cifs_fattr *fattr)
  73 {
  74         struct dentry *dentry, *alias;
  75         struct inode *inode;
  76         struct super_block *sb = parent->d_inode->i_sb;
  77
  78         cFYI(1, ("For %s", name->name));
  79
  80         dentry = d_lookup(parent, name);
  81         if (dentry) {
  82                 /* FIXME: check for inode number changes? */
  83                 if (dentry->d_inode != NULL)
  84                         return dentry;
  85                 d_drop(dentry);
  86                 dput(dentry);
  87         }
  88
  89         dentry = d_alloc(parent, name);
  90         if (dentry == NULL)
  91                 return NULL;
  92
  93         inode = cifs_iget(sb, fattr);
  94         if (!inode) {
  95                 dput(dentry);
  96                 return NULL;
  97         }
  98
  99         if (CIFS_SB(sb)->tcon->nocase)
 100                 dentry->d_op = &cifs_ci_dentry_ops;
 101         else
 102                 dentry->d_op = &cifs_dentry_ops;
 103
 104         alias = d_materialise_unique(dentry, inode);
 105         if (alias != NULL) {
 106                 dput(dentry);
 107                 if (IS_ERR(alias))
 108                         return NULL;
 109                 dentry = alias;
 110         }
 111
 112         return dentry;
 113 }
 114
 115 static void
 116 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 117 {
 118         fattr->cf_uid = cifs_sb->mnt_uid;
 119         fattr->cf_gid = cifs_sb->mnt_gid;
 120
 121         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 122                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 123                 fattr->cf_dtype = DT_DIR;
 124         } else {
 125                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 126                 fattr->cf_dtype = DT_REG;
 127         }
 128
 129         if (fattr->cf_cifsattrs & ATTR_READONLY)
 130                 fattr->cf_mode &= ~S_IWUGO;
 131
 132         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 133             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 134                 if (fattr->cf_eof == 0)  {
 135                         fattr->cf_mode &= ~S_IFMT;
 136                         fattr->cf_mode |= S_IFIFO;
 137                         fattr->cf_dtype = DT_FIFO;
 138                 } else {
 139                         /*
 140                          * trying to get the type and mode via SFU can be slow,
 141                          * so just call those regular files for now, and mark
 142                          * for reval
 143                          */
 144                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 145                 }
 146         }
 147 }
 148
 149 static void
 150 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 151                        struct cifs_sb_info *cifs_sb)
 152 {
 153         memset(fattr, 0, sizeof(*fattr));
 154         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 155         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 156         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 157         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 158         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 159         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 160
 161         cifs_fill_common_info(fattr, cifs_sb);
 162 }
 163
 164 static void
 165 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 166                        struct cifs_sb_info *cifs_sb)
 167 {
 168         int offset = cifs_sb->tcon->ses->server->timeAdj;
 169
 170         memset(fattr, 0, sizeof(*fattr));
 171         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 172                                             info->LastAccessTime, offset);
 173         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 174                                             info->LastWriteTime, offset);
 175         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 176                                             info->LastWriteTime, offset);
 177
 178         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 179         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 180         fattr->cf_eof = le32_to_cpu(info->DataSize);
 181
 182         cifs_fill_common_info(fattr, cifs_sb);
 183 }
 184
 185 /* BB eventually need to add the following helper function to
 186       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 187       we try to do FindFirst on (NTFS) directory symlinks */
 188 /*
 189 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 190                              int xid)
 191 {
 192         __u16 fid;
 193         int len;
 194         int oplock = 0;
 195         int rc;
 196         struct cifsTconInfo *ptcon = cifs_sb->tcon;
 197         char *tmpbuffer;
 198
 199         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 200                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 201                         cifs_sb->local_nls,
 202                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 203         if (!rc) {
 204                 tmpbuffer = kmalloc(maxpath);
 205                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 206                                 tmpbuffer,
 207                                 maxpath -1,
 208                                 fid,
 209                                 cifs_sb->local_nls);
 210                 if (CIFSSMBClose(xid, ptcon, fid)) {
 211                         cFYI(1, ("Error closing temporary reparsepoint open)"));
 212                 }
 213         }
 214 }
 215  */
 216
 217 static int initiate_cifs_search(const int xid, struct file *file)
 218 {
 219         int rc = 0;
 220         char *full_path;
 221         struct cifsFileInfo *cifsFile;
 222         struct cifs_sb_info *cifs_sb;
 223         struct cifsTconInfo *pTcon;
 224
 225         if (file->private_data == NULL) {
 226                 file->private_data =
 227                         kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 228         }
 229
 230         if (file->private_data == NULL)
 231                 return -ENOMEM;
 232         cifsFile = file->private_data;
 233         cifsFile->invalidHandle = true;
 234         cifsFile->srch_inf.endOfSearch = false;
 235
 236         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 237         if (cifs_sb == NULL)
 238                 return -EINVAL;
 239
 240         pTcon = cifs_sb->tcon;
 241         if (pTcon == NULL)
 242                 return -EINVAL;
 243
 244         full_path = build_path_from_dentry(file->f_path.dentry);
 245
 246         if (full_path == NULL)
 247                 return -ENOMEM;
 248
 249         cFYI(1, ("Full path: %s start at: %lld", full_path, file->f_pos));
 250
 251 ffirst_retry:
 252         /* test for Unix extensions */
 253         /* but now check for them on the share/mount not on the SMB session */
 254 /*      if (pTcon->ses->capabilities & CAP_UNIX) { */
 255         if (pTcon->unix_ext)
 256                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 257         else if ((pTcon->ses->capabilities &
 258                         (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
 259                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 260         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 261                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 262         } else /* not srvinos - BB fixme add check for backlevel? */ {
 263                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 264         }
 265
 266         rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
 267                 &cifsFile->netfid, &cifsFile->srch_inf,
 268                 cifs_sb->mnt_cifs_flags &
 269                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
 270         if (rc == 0)
 271                 cifsFile->invalidHandle = false;
 272         /* BB add following call to handle readdir on new NTFS symlink errors
 273         else if STATUS_STOPPED_ON_SYMLINK
 274                 call get_symlink_reparse_path and retry with new path */
 275         else if ((rc == -EOPNOTSUPP) &&
 276                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 277                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 278                 goto ffirst_retry;
 279         }
 280         kfree(full_path);
 281         return rc;
 282 }
 283
 284 /* return length of unicode string in bytes */
 285 static int cifs_unicode_bytelen(char *str)
 286 {
 287         int len;
 288         __le16 *ustr = (__le16 *)str;
 289
 290         for (len = 0; len <= PATH_MAX; len++) {
 291                 if (ustr[len] == 0)
 292                         return len << 1;
 293         }
 294         cFYI(1, ("Unicode string longer than PATH_MAX found"));
 295         return len << 1;
 296 }
 297
 298 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 299 {
 300         char *new_entry;
 301         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 302
 303         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 304                 FIND_FILE_STANDARD_INFO *pfData;
 305                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 306
 307                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 308                                 pfData->FileNameLength;
 309         } else
 310                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 311         cFYI(1, ("new entry %p old entry %p", new_entry, old_entry));
 312         /* validate that new_entry is not past end of SMB */
 313         if (new_entry >= end_of_smb) {
 314                 cERROR(1,
 315                       ("search entry %p began after end of SMB %p old entry %p",
 316                         new_entry, end_of_smb, old_entry));
 317                 return NULL;
 318         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 319                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 320                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 321                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 322                 cERROR(1, ("search entry %p extends after end of SMB %p",
 323                         new_entry, end_of_smb));
 324                 return NULL;
 325         } else
 326                 return new_entry;
 327
 328 }
 329
 330 #define UNICODE_DOT cpu_to_le16(0x2e)
 331
 332 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 333 static int cifs_entry_is_dot(char *current_entry, struct cifsFileInfo *cfile)
 334 {
 335         int rc = 0;
 336         char *filename = NULL;
 337         int len = 0;
 338
 339         if (cfile->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
 340                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 341                 filename = &pFindData->FileName[0];
 342                 if (cfile->srch_inf.unicode) {
 343                         len = cifs_unicode_bytelen(filename);
 344                 } else {
 345                         /* BB should we make this strnlen of PATH_MAX? */
 346                         len = strnlen(filename, 5);
 347                 }
 348         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_DIRECTORY_INFO) {
 349                 FILE_DIRECTORY_INFO *pFindData =
 350                         (FILE_DIRECTORY_INFO *)current_entry;
 351                 filename = &pFindData->FileName[0];
 352                 len = le32_to_cpu(pFindData->FileNameLength);
 353         } else if (cfile->srch_inf.info_level ==
 354                         SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 355                 FILE_FULL_DIRECTORY_INFO *pFindData =
 356                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 357                 filename = &pFindData->FileName[0];
 358                 len = le32_to_cpu(pFindData->FileNameLength);
 359         } else if (cfile->srch_inf.info_level ==
 360                         SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 361                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 362                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 363                 filename = &pFindData->FileName[0];
 364                 len = le32_to_cpu(pFindData->FileNameLength);
 365         } else if (cfile->srch_inf.info_level ==
 366                         SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 367                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 368                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 369                 filename = &pFindData->FileName[0];
 370                 len = le32_to_cpu(pFindData->FileNameLength);
 371         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD) {
 372                 FIND_FILE_STANDARD_INFO *pFindData =
 373                         (FIND_FILE_STANDARD_INFO *)current_entry;
 374                 filename = &pFindData->FileName[0];
 375                 len = pFindData->FileNameLength;
 376         } else {
 377                 cFYI(1, ("Unknown findfirst level %d",
 378                          cfile->srch_inf.info_level));
 379         }
 380
 381         if (filename) {
 382                 if (cfile->srch_inf.unicode) {
 383                         __le16 *ufilename = (__le16 *)filename;
 384                         if (len == 2) {
 385                                 /* check for . */
 386                                 if (ufilename[0] == UNICODE_DOT)
 387                                         rc = 1;
 388                         } else if (len == 4) {
 389                                 /* check for .. */
 390                                 if ((ufilename[0] == UNICODE_DOT)
 391                                    && (ufilename[1] == UNICODE_DOT))
 392                                         rc = 2;
 393                         }
 394                 } else /* ASCII */ {
 395                         if (len == 1) {
 396                                 if (filename[0] == '.')
 397                                         rc = 1;
 398                         } else if (len == 2) {
 399                                 if ((filename[0] == '.') && (filename[1] == '.'))
 400                                         rc = 2;
 401                         }
 402                 }
 403         }
 404
 405         return rc;
 406 }
 407
 408 /* Check if directory that we are searching has changed so we can decide
 409    whether we can use the cached search results from the previous search */
 410 static int is_dir_changed(struct file *file)
 411 {
 412         struct inode *inode = file->f_path.dentry->d_inode;
 413         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 414
 415         if (cifsInfo->time == 0)
 416                 return 1; /* directory was changed, perhaps due to unlink */
 417         else
 418                 return 0;
 419
 420 }
 421
 422 static int cifs_save_resume_key(const char *current_entry,
 423         struct cifsFileInfo *cifsFile)
 424 {
 425         int rc = 0;
 426         unsigned int len = 0;
 427         __u16 level;
 428         char *filename;
 429
 430         if ((cifsFile == NULL) || (current_entry == NULL))
 431                 return -EINVAL;
 432
 433         level = cifsFile->srch_inf.info_level;
 434
 435         if (level == SMB_FIND_FILE_UNIX) {
 436                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 437
 438                 filename = &pFindData->FileName[0];
 439                 if (cifsFile->srch_inf.unicode) {
 440                         len = cifs_unicode_bytelen(filename);
 441                 } else {
 442                         /* BB should we make this strnlen of PATH_MAX? */
 443                         len = strnlen(filename, PATH_MAX);
 444                 }
 445                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 446         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 447                 FILE_DIRECTORY_INFO *pFindData =
 448                         (FILE_DIRECTORY_INFO *)current_entry;
 449                 filename = &pFindData->FileName[0];
 450                 len = le32_to_cpu(pFindData->FileNameLength);
 451                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 452         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 453                 FILE_FULL_DIRECTORY_INFO *pFindData =
 454                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 455                 filename = &pFindData->FileName[0];
 456                 len = le32_to_cpu(pFindData->FileNameLength);
 457                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 458         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 459                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 460                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 461                 filename = &pFindData->FileName[0];
 462                 len = le32_to_cpu(pFindData->FileNameLength);
 463                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 464         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 465                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 466                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 467                 filename = &pFindData->FileName[0];
 468                 len = le32_to_cpu(pFindData->FileNameLength);
 469                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 470         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 471                 FIND_FILE_STANDARD_INFO *pFindData =
 472                         (FIND_FILE_STANDARD_INFO *)current_entry;
 473                 filename = &pFindData->FileName[0];
 474                 /* one byte length, no name conversion */
 475                 len = (unsigned int)pFindData->FileNameLength;
 476                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 477         } else {
 478                 cFYI(1, ("Unknown findfirst level %d", level));
 479                 return -EINVAL;
 480         }
 481         cifsFile->srch_inf.resume_name_len = len;
 482         cifsFile->srch_inf.presume_name = filename;
 483         return rc;
 484 }
 485
 486 /* find the corresponding entry in the search */
 487 /* Note that the SMB server returns search entries for . and .. which
 488    complicates logic here if we choose to parse for them and we do not
 489    assume that they are located in the findfirst return buffer.*/
 490 /* We start counting in the buffer with entry 2 and increment for every
 491    entry (do not increment for . or .. entry) */
 492 static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
 493         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 494 {
 495         int rc = 0;
 496         int pos_in_buf = 0;
 497         loff_t first_entry_in_buffer;
 498         loff_t index_to_find = file->f_pos;
 499         struct cifsFileInfo *cifsFile = file->private_data;
 500         /* check if index in the buffer */
 501
 502         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 503            (num_to_ret == NULL))
 504                 return -ENOENT;
 505
 506         *ppCurrentEntry = NULL;
 507         first_entry_in_buffer =
 508                 cifsFile->srch_inf.index_of_last_entry -
 509                         cifsFile->srch_inf.entries_in_buffer;
 510
 511         /* if first entry in buf is zero then is first buffer
 512         in search response data which means it is likely . and ..
 513         will be in this buffer, although some servers do not return
 514         . and .. for the root of a drive and for those we need
 515         to start two entries earlier */
 516
 517         dump_cifs_file_struct(file, "In fce ");
 518         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 519              is_dir_changed(file)) ||
 520            (index_to_find < first_entry_in_buffer)) {
 521                 /* close and restart search */
 522                 cFYI(1, ("search backing up - close and restart search"));
 523                 write_lock(&GlobalSMBSeslock);
 524                 if (!cifsFile->srch_inf.endOfSearch &&
 525                     !cifsFile->invalidHandle) {
 526                         cifsFile->invalidHandle = true;
 527                         write_unlock(&GlobalSMBSeslock);
 528                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 529                 } else
 530                         write_unlock(&GlobalSMBSeslock);
 531                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 532                         cFYI(1, ("freeing SMB ff cache buf on search rewind"));
 533                         if (cifsFile->srch_inf.smallBuf)
 534                                 cifs_small_buf_release(cifsFile->srch_inf.
 535                                                 ntwrk_buf_start);
 536                         else
 537                                 cifs_buf_release(cifsFile->srch_inf.
 538                                                 ntwrk_buf_start);
 539                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 540                 }
 541                 rc = initiate_cifs_search(xid, file);
 542                 if (rc) {
 543                         cFYI(1, ("error %d reinitiating a search on rewind",
 544                                  rc));
 545                         return rc;
 546                 }
 547                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 548         }
 549
 550         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 551               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 552                 cFYI(1, ("calling findnext2"));
 553                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
 554                                   &cifsFile->srch_inf);
 555                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 556                 if (rc)
 557                         return -ENOENT;
 558         }
 559         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 560                 /* we found the buffer that contains the entry */
 561                 /* scan and find it */
 562                 int i;
 563                 char *current_entry;
 564                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 565                         smbCalcSize((struct smb_hdr *)
 566                                 cifsFile->srch_inf.ntwrk_buf_start);
 567
 568                 current_entry = cifsFile->srch_inf.srch_entries_start;
 569                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 570                                         - cifsFile->srch_inf.entries_in_buffer;
 571                 pos_in_buf = index_to_find - first_entry_in_buffer;
 572                 cFYI(1, ("found entry - pos_in_buf %d", pos_in_buf));
 573
 574                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 575                         /* go entry by entry figuring out which is first */
 576                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 577                                                 cifsFile->srch_inf.info_level);
 578                 }
 579                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 580                         /* BB fixme - check if we should flag this error */
 581                         cERROR(1, ("reached end of buf searching for pos in buf"
 582                           " %d index to find %lld rc %d",
 583                           pos_in_buf, index_to_find, rc));
 584                 }
 585                 rc = 0;
 586                 *ppCurrentEntry = current_entry;
 587         } else {
 588                 cFYI(1, ("index not in buffer - could not findnext into it"));
 589                 return 0;
 590         }
 591
 592         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 593                 cFYI(1, ("can not return entries pos_in_buf beyond last"));
 594                 *num_to_ret = 0;
 595         } else
 596                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 597
 598         return rc;
 599 }
 600
 601 /* inode num, inode type and filename returned */
 602 static int cifs_get_name_from_search_buf(struct qstr *pqst,
 603         char *current_entry, __u16 level, unsigned int unicode,
 604         struct cifs_sb_info *cifs_sb, unsigned int max_len, __u64 *pinum)
 605 {
 606         int rc = 0;
 607         unsigned int len = 0;
 608         char *filename;
 609         struct nls_table *nlt = cifs_sb->local_nls;
 610
 611         *pinum = 0;
 612
 613         if (level == SMB_FIND_FILE_UNIX) {
 614                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 615
 616                 filename = &pFindData->FileName[0];
 617                 if (unicode) {
 618                         len = cifs_unicode_bytelen(filename);
 619                 } else {
 620                         /* BB should we make this strnlen of PATH_MAX? */
 621                         len = strnlen(filename, PATH_MAX);
 622                 }
 623
 624                 *pinum = le64_to_cpu(pFindData->basic.UniqueId);
 625         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 626                 FILE_DIRECTORY_INFO *pFindData =
 627                         (FILE_DIRECTORY_INFO *)current_entry;
 628                 filename = &pFindData->FileName[0];
 629                 len = le32_to_cpu(pFindData->FileNameLength);
 630         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 631                 FILE_FULL_DIRECTORY_INFO *pFindData =
 632                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 633                 filename = &pFindData->FileName[0];
 634                 len = le32_to_cpu(pFindData->FileNameLength);
 635         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 636                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 637                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 638                 filename = &pFindData->FileName[0];
 639                 len = le32_to_cpu(pFindData->FileNameLength);
 640                 *pinum = le64_to_cpu(pFindData->UniqueId);
 641         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 642                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 643                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 644                 filename = &pFindData->FileName[0];
 645                 len = le32_to_cpu(pFindData->FileNameLength);
 646         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 647                 FIND_FILE_STANDARD_INFO *pFindData =
 648                         (FIND_FILE_STANDARD_INFO *)current_entry;
 649                 filename = &pFindData->FileName[0];
 650                 /* one byte length, no name conversion */
 651                 len = (unsigned int)pFindData->FileNameLength;
 652         } else {
 653                 cFYI(1, ("Unknown findfirst level %d", level));
 654                 return -EINVAL;
 655         }
 656
 657         if (len > max_len) {
 658                 cERROR(1, ("bad search response length %d past smb end", len));
 659                 return -EINVAL;
 660         }
 661
 662         if (unicode) {
 663                 pqst->len = cifs_from_ucs2((char *) pqst->name,
 664                                            (__le16 *) filename,
 665                                            UNICODE_NAME_MAX,
 666                                            min(len, max_len), nlt,
 667                                            cifs_sb->mnt_cifs_flags &
 668                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 669         } else {
 670                 pqst->name = filename;
 671                 pqst->len = len;
 672         }
 673         pqst->hash = full_name_hash(pqst->name, pqst->len);
 674 /*      cFYI(1, ("filldir on %s",pqst->name));  */
 675         return rc;
 676 }
 677
 678 static int cifs_filldir(char *pfindEntry, struct file *file, filldir_t filldir,
 679                         void *direntry, char *scratch_buf, unsigned int max_len)
 680 {
 681         int rc = 0;
 682         struct qstr qstring;
 683         struct cifsFileInfo *pCifsF;
 684         u64    inum;
 685         ino_t  ino;
 686         struct super_block *sb;
 687         struct cifs_sb_info *cifs_sb;
 688         struct dentry *tmp_dentry;
 689         struct cifs_fattr fattr;
 690
 691         /* get filename and len into qstring */
 692         /* get dentry */
 693         /* decide whether to create and populate ionde */
 694         if ((direntry == NULL) || (file == NULL))
 695                 return -EINVAL;
 696
 697         pCifsF = file->private_data;
 698
 699         if ((scratch_buf == NULL) || (pfindEntry == NULL) || (pCifsF == NULL))
 700                 return -ENOENT;
 701
 702         rc = cifs_entry_is_dot(pfindEntry, pCifsF);
 703         /* skip . and .. since we added them first */
 704         if (rc != 0)
 705                 return 0;
 706
 707         sb = file->f_path.dentry->d_sb;
 708         cifs_sb = CIFS_SB(sb);
 709
 710         qstring.name = scratch_buf;
 711         rc = cifs_get_name_from_search_buf(&qstring, pfindEntry,
 712                         pCifsF->srch_inf.info_level,
 713                         pCifsF->srch_inf.unicode, cifs_sb,
 714                         max_len, &inum /* returned */);
 715
 716         if (rc)
 717                 return rc;
 718
 719         if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX)
 720                 cifs_unix_basic_to_fattr(&fattr,
 721                                  &((FILE_UNIX_INFO *) pfindEntry)->basic,
 722                                  cifs_sb);
 723         else if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD)
 724                 cifs_std_info_to_fattr(&fattr, (FIND_FILE_STANDARD_INFO *)
 725                                         pfindEntry, cifs_sb);
 726         else
 727                 cifs_dir_info_to_fattr(&fattr, (FILE_DIRECTORY_INFO *)
 728                                         pfindEntry, cifs_sb);
 729
 730         /* FIXME: make _to_fattr functions fill this out */
 731         if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_ID_FULL_DIR_INFO)
 732                 fattr.cf_uniqueid = inum;
 733         else
 734                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 735
 736         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 737         tmp_dentry = cifs_readdir_lookup(file->f_dentry, &qstring, &fattr);
 738
 739         rc = filldir(direntry, qstring.name, qstring.len, file->f_pos,
 740                      ino, fattr.cf_dtype);
 741
 742         /*
 743          * we can not return filldir errors to the caller since they are
 744          * "normal" when the stat blocksize is too small - we return remapped
 745          * error instead
 746          *
 747          * FIXME: This looks bogus. filldir returns -EOVERFLOW in the above
 748          * case already. Why should we be clobbering other errors from it?
 749          */
 750         if (rc) {
 751                 cFYI(1, ("filldir rc = %d", rc));
 752                 rc = -EOVERFLOW;
 753         }
 754         dput(tmp_dentry);
 755         return rc;
 756 }
 757
 758
 759 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 760 {
 761         int rc = 0;
 762         int xid, i;
 763         struct cifs_sb_info *cifs_sb;
 764         struct cifsTconInfo *pTcon;
 765         struct cifsFileInfo *cifsFile = NULL;
 766         char *current_entry;
 767         int num_to_fill = 0;
 768         char *tmp_buf = NULL;
 769         char *end_of_smb;
 770         unsigned int max_len;
 771
 772         xid = GetXid();
 773
 774         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 775         pTcon = cifs_sb->tcon;
 776         if (pTcon == NULL)
 777                 return -EINVAL;
 778
 779         switch ((int) file->f_pos) {
 780         case 0:
 781                 if (filldir(direntry, ".", 1, file->f_pos,
 782                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 783                         cERROR(1, ("Filldir for current dir failed"));
 784                         rc = -ENOMEM;
 785                         break;
 786                 }
 787                 file->f_pos++;
 788         case 1:
 789                 if (filldir(direntry, "..", 2, file->f_pos,
 790                      file->f_path.dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
 791                         cERROR(1, ("Filldir for parent dir failed"));
 792                         rc = -ENOMEM;
 793                         break;
 794                 }
 795                 file->f_pos++;
 796         default:
 797                 /* 1) If search is active,
 798                         is in current search buffer?
 799                         if it before then restart search
 800                         if after then keep searching till find it */
 801
 802                 if (file->private_data == NULL) {
 803                         rc = initiate_cifs_search(xid, file);
 804                         cFYI(1, ("initiate cifs search rc %d", rc));
 805                         if (rc) {
 806                                 FreeXid(xid);
 807                                 return rc;
 808                         }
 809                 }
 810                 if (file->private_data == NULL) {
 811                         rc = -EINVAL;
 812                         FreeXid(xid);
 813                         return rc;
 814                 }
 815                 cifsFile = file->private_data;
 816                 if (cifsFile->srch_inf.endOfSearch) {
 817                         if (cifsFile->srch_inf.emptyDir) {
 818                                 cFYI(1, ("End of search, empty dir"));
 819                                 rc = 0;
 820                                 break;
 821                         }
 822                 } /* else {
 823                         cifsFile->invalidHandle = true;
 824                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 825                 } */
 826
 827                 rc = find_cifs_entry(xid, pTcon, file,
 828                                 &current_entry, &num_to_fill);
 829                 if (rc) {
 830                         cFYI(1, ("fce error %d", rc));
 831                         goto rddir2_exit;
 832                 } else if (current_entry != NULL) {
 833                         cFYI(1, ("entry %lld found", file->f_pos));
 834                 } else {
 835                         cFYI(1, ("could not find entry"));
 836                         goto rddir2_exit;
 837                 }
 838                 cFYI(1, ("loop through %d times filling dir for net buf %p",
 839                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start));
 840                 max_len = smbCalcSize((struct smb_hdr *)
 841                                 cifsFile->srch_inf.ntwrk_buf_start);
 842                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 843
 844                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 845                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 846                         if (current_entry == NULL) {
 847                                 /* evaluate whether this case is an error */
 848                                 cERROR(1, ("past SMB end,  num to fill %d i %d",
 849                                           num_to_fill, i));
 850                                 break;
 851                         }
 852                         /* if buggy server returns . and .. late do
 853                         we want to check for that here? */
 854                         rc = cifs_filldir(current_entry, file,
 855                                         filldir, direntry, tmp_buf, max_len);
 856                         if (rc == -EOVERFLOW) {
 857                                 rc = 0;
 858                                 break;
 859                         }
 860
 861                         file->f_pos++;
 862                         if (file->f_pos ==
 863                                 cifsFile->srch_inf.index_of_last_entry) {
 864                                 cFYI(1, ("last entry in buf at pos %lld %s",
 865                                         file->f_pos, tmp_buf));
 866                                 cifs_save_resume_key(current_entry, cifsFile);
 867                                 break;
 868                         } else
 869                                 current_entry =
 870                                         nxt_dir_entry(current_entry, end_of_smb,
 871                                                 cifsFile->srch_inf.info_level);
 872                 }
 873                 kfree(tmp_buf);
 874                 break;
 875         } /* end switch */
 876
 877 rddir2_exit:
 878         FreeXid(xid);
 879         return rc;
 880 }