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/slab.h>
  26 #include <linux/stat.h>
  27 #include "cifspdu.h"
  28 #include "cifsglob.h"
  29 #include "cifsproto.h"
  30 #include "cifs_unicode.h"
  31 #include "cifs_debug.h"
  32 #include "cifs_fs_sb.h"
  33 #include "cifsfs.h"
  34
  35 /*
  36  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  37  * characters alloc more to account for such multibyte target UTF-8
  38  * characters.
  39  */
  40 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  41
  42 #ifdef CONFIG_CIFS_DEBUG2
  43 static void dump_cifs_file_struct(struct file *file, char *label)
  44 {
  45         struct cifsFileInfo *cf;
  46
  47         if (file) {
  48                 cf = file->private_data;
  49                 if (cf == NULL) {
  50                         cFYI(1, "empty cifs private file data");
  51                         return;
  52                 }
  53                 if (cf->invalidHandle)
  54                         cFYI(1, "invalid handle");
  55                 if (cf->srch_inf.endOfSearch)
  56                         cFYI(1, "end of search");
  57                 if (cf->srch_inf.emptyDir)
  58                         cFYI(1, "empty dir");
  59         }
  60 }
  61 #else
  62 static inline void dump_cifs_file_struct(struct file *file, char *label)
  63 {
  64 }
  65 #endif /* DEBUG2 */
  66
  67 /*
  68  * Find the dentry that matches "name". If there isn't one, create one. If it's
  69  * a negative dentry or the uniqueid changed, then drop it and recreate it.
  70  */
  71 static struct dentry *
  72 cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
  73                     struct cifs_fattr *fattr)
  74 {
  75         struct dentry *dentry, *alias;
  76         struct inode *inode;
  77         struct super_block *sb = parent->d_inode->i_sb;
  78
  79         cFYI(1, "For %s", name->name);
  80
  81         if (parent->d_op && parent->d_op->d_hash)
  82                 parent->d_op->d_hash(parent, name);
  83         else
  84                 name->hash = full_name_hash(name->name, name->len);
  85
  86         dentry = d_lookup(parent, name);
  87         if (dentry) {
  88                 /* FIXME: check for inode number changes? */
  89                 if (dentry->d_inode != NULL)
  90                         return dentry;
  91                 d_drop(dentry);
  92                 dput(dentry);
  93         }
  94
  95         dentry = d_alloc(parent, name);
  96         if (dentry == NULL)
  97                 return NULL;
  98
  99         inode = cifs_iget(sb, fattr);
 100         if (!inode) {
 101                 dput(dentry);
 102                 return NULL;
 103         }
 104
 105         if (CIFS_SB(sb)->tcon->nocase)
 106                 dentry->d_op = &cifs_ci_dentry_ops;
 107         else
 108                 dentry->d_op = &cifs_dentry_ops;
 109
 110         alias = d_materialise_unique(dentry, inode);
 111         if (alias != NULL) {
 112                 dput(dentry);
 113                 if (IS_ERR(alias))
 114                         return NULL;
 115                 dentry = alias;
 116         }
 117
 118         return dentry;
 119 }
 120
 121 static void
 122 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 123 {
 124         fattr->cf_uid = cifs_sb->mnt_uid;
 125         fattr->cf_gid = cifs_sb->mnt_gid;
 126
 127         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 128                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 129                 fattr->cf_dtype = DT_DIR;
 130         } else {
 131                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 132                 fattr->cf_dtype = DT_REG;
 133         }
 134
 135         if (fattr->cf_cifsattrs & ATTR_READONLY)
 136                 fattr->cf_mode &= ~S_IWUGO;
 137
 138         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 139             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 140                 if (fattr->cf_eof == 0)  {
 141                         fattr->cf_mode &= ~S_IFMT;
 142                         fattr->cf_mode |= S_IFIFO;
 143                         fattr->cf_dtype = DT_FIFO;
 144                 } else {
 145                         /*
 146                          * trying to get the type and mode via SFU can be slow,
 147                          * so just call those regular files for now, and mark
 148                          * for reval
 149                          */
 150                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 151                 }
 152         }
 153 }
 154
 155 static void
 156 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 157                        struct cifs_sb_info *cifs_sb)
 158 {
 159         memset(fattr, 0, sizeof(*fattr));
 160         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 161         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 162         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 163         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 164         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 165         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 166
 167         cifs_fill_common_info(fattr, cifs_sb);
 168 }
 169
 170 static void
 171 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 172                        struct cifs_sb_info *cifs_sb)
 173 {
 174         int offset = cifs_sb->tcon->ses->server->timeAdj;
 175
 176         memset(fattr, 0, sizeof(*fattr));
 177         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 178                                             info->LastAccessTime, offset);
 179         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 180                                             info->LastWriteTime, offset);
 181         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 182                                             info->LastWriteTime, offset);
 183
 184         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 185         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 186         fattr->cf_eof = le32_to_cpu(info->DataSize);
 187
 188         cifs_fill_common_info(fattr, cifs_sb);
 189 }
 190
 191 /* BB eventually need to add the following helper function to
 192       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 193       we try to do FindFirst on (NTFS) directory symlinks */
 194 /*
 195 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 196                              int xid)
 197 {
 198         __u16 fid;
 199         int len;
 200         int oplock = 0;
 201         int rc;
 202         struct cifsTconInfo *ptcon = cifs_sb->tcon;
 203         char *tmpbuffer;
 204
 205         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 206                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 207                         cifs_sb->local_nls,
 208                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 209         if (!rc) {
 210                 tmpbuffer = kmalloc(maxpath);
 211                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 212                                 tmpbuffer,
 213                                 maxpath -1,
 214                                 fid,
 215                                 cifs_sb->local_nls);
 216                 if (CIFSSMBClose(xid, ptcon, fid)) {
 217                         cFYI(1, "Error closing temporary reparsepoint open");
 218                 }
 219         }
 220 }
 221  */
 222
 223 static int initiate_cifs_search(const int xid, struct file *file)
 224 {
 225         int rc = 0;
 226         char *full_path;
 227         struct cifsFileInfo *cifsFile;
 228         struct cifs_sb_info *cifs_sb;
 229         struct cifsTconInfo *pTcon;
 230
 231         if (file->private_data == NULL) {
 232                 file->private_data =
 233                         kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 234         }
 235
 236         if (file->private_data == NULL)
 237                 return -ENOMEM;
 238         cifsFile = file->private_data;
 239         cifsFile->invalidHandle = true;
 240         cifsFile->srch_inf.endOfSearch = false;
 241
 242         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 243         if (cifs_sb == NULL)
 244                 return -EINVAL;
 245
 246         pTcon = cifs_sb->tcon;
 247         if (pTcon == NULL)
 248                 return -EINVAL;
 249
 250         full_path = build_path_from_dentry(file->f_path.dentry);
 251
 252         if (full_path == NULL)
 253                 return -ENOMEM;
 254
 255         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 256
 257 ffirst_retry:
 258         /* test for Unix extensions */
 259         /* but now check for them on the share/mount not on the SMB session */
 260 /*      if (pTcon->ses->capabilities & CAP_UNIX) { */
 261         if (pTcon->unix_ext)
 262                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 263         else if ((pTcon->ses->capabilities &
 264                         (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
 265                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 266         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 267                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 268         } else /* not srvinos - BB fixme add check for backlevel? */ {
 269                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 270         }
 271
 272         rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
 273                 &cifsFile->netfid, &cifsFile->srch_inf,
 274                 cifs_sb->mnt_cifs_flags &
 275                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
 276         if (rc == 0)
 277                 cifsFile->invalidHandle = false;
 278         /* BB add following call to handle readdir on new NTFS symlink errors
 279         else if STATUS_STOPPED_ON_SYMLINK
 280                 call get_symlink_reparse_path and retry with new path */
 281         else if ((rc == -EOPNOTSUPP) &&
 282                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 283                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 284                 goto ffirst_retry;
 285         }
 286         kfree(full_path);
 287         return rc;
 288 }
 289
 290 /* return length of unicode string in bytes */
 291 static int cifs_unicode_bytelen(char *str)
 292 {
 293         int len;
 294         __le16 *ustr = (__le16 *)str;
 295
 296         for (len = 0; len <= PATH_MAX; len++) {
 297                 if (ustr[len] == 0)
 298                         return len << 1;
 299         }
 300         cFYI(1, "Unicode string longer than PATH_MAX found");
 301         return len << 1;
 302 }
 303
 304 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 305 {
 306         char *new_entry;
 307         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 308
 309         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 310                 FIND_FILE_STANDARD_INFO *pfData;
 311                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 312
 313                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 314                                 pfData->FileNameLength;
 315         } else
 316                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 317         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 318         /* validate that new_entry is not past end of SMB */
 319         if (new_entry >= end_of_smb) {
 320                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 321                         new_entry, end_of_smb, old_entry);
 322                 return NULL;
 323         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 324                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 325                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 326                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 327                 cERROR(1, "search entry %p extends after end of SMB %p",
 328                         new_entry, end_of_smb);
 329                 return NULL;
 330         } else
 331                 return new_entry;
 332
 333 }
 334
 335 #define UNICODE_DOT cpu_to_le16(0x2e)
 336
 337 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 338 static int cifs_entry_is_dot(char *current_entry, struct cifsFileInfo *cfile)
 339 {
 340         int rc = 0;
 341         char *filename = NULL;
 342         int len = 0;
 343
 344         if (cfile->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
 345                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 346                 filename = &pFindData->FileName[0];
 347                 if (cfile->srch_inf.unicode) {
 348                         len = cifs_unicode_bytelen(filename);
 349                 } else {
 350                         /* BB should we make this strnlen of PATH_MAX? */
 351                         len = strnlen(filename, 5);
 352                 }
 353         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_DIRECTORY_INFO) {
 354                 FILE_DIRECTORY_INFO *pFindData =
 355                         (FILE_DIRECTORY_INFO *)current_entry;
 356                 filename = &pFindData->FileName[0];
 357                 len = le32_to_cpu(pFindData->FileNameLength);
 358         } else if (cfile->srch_inf.info_level ==
 359                         SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 360                 FILE_FULL_DIRECTORY_INFO *pFindData =
 361                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 362                 filename = &pFindData->FileName[0];
 363                 len = le32_to_cpu(pFindData->FileNameLength);
 364         } else if (cfile->srch_inf.info_level ==
 365                         SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 366                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 367                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 368                 filename = &pFindData->FileName[0];
 369                 len = le32_to_cpu(pFindData->FileNameLength);
 370         } else if (cfile->srch_inf.info_level ==
 371                         SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 372                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 373                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 374                 filename = &pFindData->FileName[0];
 375                 len = le32_to_cpu(pFindData->FileNameLength);
 376         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD) {
 377                 FIND_FILE_STANDARD_INFO *pFindData =
 378                         (FIND_FILE_STANDARD_INFO *)current_entry;
 379                 filename = &pFindData->FileName[0];
 380                 len = pFindData->FileNameLength;
 381         } else {
 382                 cFYI(1, "Unknown findfirst level %d",
 383                          cfile->srch_inf.info_level);
 384         }
 385
 386         if (filename) {
 387                 if (cfile->srch_inf.unicode) {
 388                         __le16 *ufilename = (__le16 *)filename;
 389                         if (len == 2) {
 390                                 /* check for . */
 391                                 if (ufilename[0] == UNICODE_DOT)
 392                                         rc = 1;
 393                         } else if (len == 4) {
 394                                 /* check for .. */
 395                                 if ((ufilename[0] == UNICODE_DOT)
 396                                    && (ufilename[1] == UNICODE_DOT))
 397                                         rc = 2;
 398                         }
 399                 } else /* ASCII */ {
 400                         if (len == 1) {
 401                                 if (filename[0] == '.')
 402                                         rc = 1;
 403                         } else if (len == 2) {
 404                                 if ((filename[0] == '.') && (filename[1] == '.'))
 405                                         rc = 2;
 406                         }
 407                 }
 408         }
 409
 410         return rc;
 411 }
 412
 413 /* Check if directory that we are searching has changed so we can decide
 414    whether we can use the cached search results from the previous search */
 415 static int is_dir_changed(struct file *file)
 416 {
 417         struct inode *inode = file->f_path.dentry->d_inode;
 418         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 419
 420         if (cifsInfo->time == 0)
 421                 return 1; /* directory was changed, perhaps due to unlink */
 422         else
 423                 return 0;
 424
 425 }
 426
 427 static int cifs_save_resume_key(const char *current_entry,
 428         struct cifsFileInfo *cifsFile)
 429 {
 430         int rc = 0;
 431         unsigned int len = 0;
 432         __u16 level;
 433         char *filename;
 434
 435         if ((cifsFile == NULL) || (current_entry == NULL))
 436                 return -EINVAL;
 437
 438         level = cifsFile->srch_inf.info_level;
 439
 440         if (level == SMB_FIND_FILE_UNIX) {
 441                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 442
 443                 filename = &pFindData->FileName[0];
 444                 if (cifsFile->srch_inf.unicode) {
 445                         len = cifs_unicode_bytelen(filename);
 446                 } else {
 447                         /* BB should we make this strnlen of PATH_MAX? */
 448                         len = strnlen(filename, PATH_MAX);
 449                 }
 450                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 451         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 452                 FILE_DIRECTORY_INFO *pFindData =
 453                         (FILE_DIRECTORY_INFO *)current_entry;
 454                 filename = &pFindData->FileName[0];
 455                 len = le32_to_cpu(pFindData->FileNameLength);
 456                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 457         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 458                 FILE_FULL_DIRECTORY_INFO *pFindData =
 459                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 460                 filename = &pFindData->FileName[0];
 461                 len = le32_to_cpu(pFindData->FileNameLength);
 462                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 463         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 464                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 465                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 466                 filename = &pFindData->FileName[0];
 467                 len = le32_to_cpu(pFindData->FileNameLength);
 468                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 469         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 470                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 471                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 472                 filename = &pFindData->FileName[0];
 473                 len = le32_to_cpu(pFindData->FileNameLength);
 474                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 475         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 476                 FIND_FILE_STANDARD_INFO *pFindData =
 477                         (FIND_FILE_STANDARD_INFO *)current_entry;
 478                 filename = &pFindData->FileName[0];
 479                 /* one byte length, no name conversion */
 480                 len = (unsigned int)pFindData->FileNameLength;
 481                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 482         } else {
 483                 cFYI(1, "Unknown findfirst level %d", level);
 484                 return -EINVAL;
 485         }
 486         cifsFile->srch_inf.resume_name_len = len;
 487         cifsFile->srch_inf.presume_name = filename;
 488         return rc;
 489 }
 490
 491 /* find the corresponding entry in the search */
 492 /* Note that the SMB server returns search entries for . and .. which
 493    complicates logic here if we choose to parse for them and we do not
 494    assume that they are located in the findfirst return buffer.*/
 495 /* We start counting in the buffer with entry 2 and increment for every
 496    entry (do not increment for . or .. entry) */
 497 static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
 498         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 499 {
 500         int rc = 0;
 501         int pos_in_buf = 0;
 502         loff_t first_entry_in_buffer;
 503         loff_t index_to_find = file->f_pos;
 504         struct cifsFileInfo *cifsFile = file->private_data;
 505         /* check if index in the buffer */
 506
 507         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 508            (num_to_ret == NULL))
 509                 return -ENOENT;
 510
 511         *ppCurrentEntry = NULL;
 512         first_entry_in_buffer =
 513                 cifsFile->srch_inf.index_of_last_entry -
 514                         cifsFile->srch_inf.entries_in_buffer;
 515
 516         /* if first entry in buf is zero then is first buffer
 517         in search response data which means it is likely . and ..
 518         will be in this buffer, although some servers do not return
 519         . and .. for the root of a drive and for those we need
 520         to start two entries earlier */
 521
 522         dump_cifs_file_struct(file, "In fce ");
 523         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 524              is_dir_changed(file)) ||
 525            (index_to_find < first_entry_in_buffer)) {
 526                 /* close and restart search */
 527                 cFYI(1, "search backing up - close and restart search");
 528                 write_lock(&GlobalSMBSeslock);
 529                 if (!cifsFile->srch_inf.endOfSearch &&
 530                     !cifsFile->invalidHandle) {
 531                         cifsFile->invalidHandle = true;
 532                         write_unlock(&GlobalSMBSeslock);
 533                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 534                 } else
 535                         write_unlock(&GlobalSMBSeslock);
 536                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 537                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 538                         if (cifsFile->srch_inf.smallBuf)
 539                                 cifs_small_buf_release(cifsFile->srch_inf.
 540                                                 ntwrk_buf_start);
 541                         else
 542                                 cifs_buf_release(cifsFile->srch_inf.
 543                                                 ntwrk_buf_start);
 544                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 545                 }
 546                 rc = initiate_cifs_search(xid, file);
 547                 if (rc) {
 548                         cFYI(1, "error %d reinitiating a search on rewind",
 549                                  rc);
 550                         return rc;
 551                 }
 552                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 553         }
 554
 555         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 556               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 557                 cFYI(1, "calling findnext2");
 558                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
 559                                   &cifsFile->srch_inf);
 560                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 561                 if (rc)
 562                         return -ENOENT;
 563         }
 564         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 565                 /* we found the buffer that contains the entry */
 566                 /* scan and find it */
 567                 int i;
 568                 char *current_entry;
 569                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 570                         smbCalcSize((struct smb_hdr *)
 571                                 cifsFile->srch_inf.ntwrk_buf_start);
 572
 573                 current_entry = cifsFile->srch_inf.srch_entries_start;
 574                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 575                                         - cifsFile->srch_inf.entries_in_buffer;
 576                 pos_in_buf = index_to_find - first_entry_in_buffer;
 577                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 578
 579                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 580                         /* go entry by entry figuring out which is first */
 581                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 582                                                 cifsFile->srch_inf.info_level);
 583                 }
 584                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 585                         /* BB fixme - check if we should flag this error */
 586                         cERROR(1, "reached end of buf searching for pos in buf"
 587                           " %d index to find %lld rc %d",
 588                           pos_in_buf, index_to_find, rc);
 589                 }
 590                 rc = 0;
 591                 *ppCurrentEntry = current_entry;
 592         } else {
 593                 cFYI(1, "index not in buffer - could not findnext into it");
 594                 return 0;
 595         }
 596
 597         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 598                 cFYI(1, "can not return entries pos_in_buf beyond last");
 599                 *num_to_ret = 0;
 600         } else
 601                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 602
 603         return rc;
 604 }
 605
 606 /* inode num, inode type and filename returned */
 607 static int cifs_get_name_from_search_buf(struct qstr *pqst,
 608         char *current_entry, __u16 level, unsigned int unicode,
 609         struct cifs_sb_info *cifs_sb, unsigned int max_len, __u64 *pinum)
 610 {
 611         int rc = 0;
 612         unsigned int len = 0;
 613         char *filename;
 614         struct nls_table *nlt = cifs_sb->local_nls;
 615
 616         *pinum = 0;
 617
 618         if (level == SMB_FIND_FILE_UNIX) {
 619                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 620
 621                 filename = &pFindData->FileName[0];
 622                 if (unicode) {
 623                         len = cifs_unicode_bytelen(filename);
 624                 } else {
 625                         /* BB should we make this strnlen of PATH_MAX? */
 626                         len = strnlen(filename, PATH_MAX);
 627                 }
 628
 629                 *pinum = le64_to_cpu(pFindData->basic.UniqueId);
 630         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 631                 FILE_DIRECTORY_INFO *pFindData =
 632                         (FILE_DIRECTORY_INFO *)current_entry;
 633                 filename = &pFindData->FileName[0];
 634                 len = le32_to_cpu(pFindData->FileNameLength);
 635         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 636                 FILE_FULL_DIRECTORY_INFO *pFindData =
 637                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 638                 filename = &pFindData->FileName[0];
 639                 len = le32_to_cpu(pFindData->FileNameLength);
 640         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 641                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 642                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 643                 filename = &pFindData->FileName[0];
 644                 len = le32_to_cpu(pFindData->FileNameLength);
 645                 *pinum = le64_to_cpu(pFindData->UniqueId);
 646         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 647                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 648                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 649                 filename = &pFindData->FileName[0];
 650                 len = le32_to_cpu(pFindData->FileNameLength);
 651         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 652                 FIND_FILE_STANDARD_INFO *pFindData =
 653                         (FIND_FILE_STANDARD_INFO *)current_entry;
 654                 filename = &pFindData->FileName[0];
 655                 /* one byte length, no name conversion */
 656                 len = (unsigned int)pFindData->FileNameLength;
 657         } else {
 658                 cFYI(1, "Unknown findfirst level %d", level);
 659                 return -EINVAL;
 660         }
 661
 662         if (len > max_len) {
 663                 cERROR(1, "bad search response length %d past smb end", len);
 664                 return -EINVAL;
 665         }
 666
 667         if (unicode) {
 668                 pqst->len = cifs_from_ucs2((char *) pqst->name,
 669                                            (__le16 *) filename,
 670                                            UNICODE_NAME_MAX,
 671                                            min(len, max_len), nlt,
 672                                            cifs_sb->mnt_cifs_flags &
 673                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 674                 pqst->len -= nls_nullsize(nlt);
 675         } else {
 676                 pqst->name = filename;
 677                 pqst->len = len;
 678         }
 679         return rc;
 680 }
 681
 682 static int cifs_filldir(char *pfindEntry, struct file *file, filldir_t filldir,
 683                         void *direntry, char *scratch_buf, unsigned int max_len)
 684 {
 685         int rc = 0;
 686         struct qstr qstring;
 687         struct cifsFileInfo *pCifsF;
 688         u64    inum;
 689         ino_t  ino;
 690         struct super_block *sb;
 691         struct cifs_sb_info *cifs_sb;
 692         struct dentry *tmp_dentry;
 693         struct cifs_fattr fattr;
 694
 695         /* get filename and len into qstring */
 696         /* get dentry */
 697         /* decide whether to create and populate ionde */
 698         if ((direntry == NULL) || (file == NULL))
 699                 return -EINVAL;
 700
 701         pCifsF = file->private_data;
 702
 703         if ((scratch_buf == NULL) || (pfindEntry == NULL) || (pCifsF == NULL))
 704                 return -ENOENT;
 705
 706         rc = cifs_entry_is_dot(pfindEntry, pCifsF);
 707         /* skip . and .. since we added them first */
 708         if (rc != 0)
 709                 return 0;
 710
 711         sb = file->f_path.dentry->d_sb;
 712         cifs_sb = CIFS_SB(sb);
 713
 714         qstring.name = scratch_buf;
 715         rc = cifs_get_name_from_search_buf(&qstring, pfindEntry,
 716                         pCifsF->srch_inf.info_level,
 717                         pCifsF->srch_inf.unicode, cifs_sb,
 718                         max_len, &inum /* returned */);
 719
 720         if (rc)
 721                 return rc;
 722
 723         if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX)
 724                 cifs_unix_basic_to_fattr(&fattr,
 725                                  &((FILE_UNIX_INFO *) pfindEntry)->basic,
 726                                  cifs_sb);
 727         else if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD)
 728                 cifs_std_info_to_fattr(&fattr, (FIND_FILE_STANDARD_INFO *)
 729                                         pfindEntry, cifs_sb);
 730         else
 731                 cifs_dir_info_to_fattr(&fattr, (FILE_DIRECTORY_INFO *)
 732                                         pfindEntry, cifs_sb);
 733
 734         if (inum && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 735                 fattr.cf_uniqueid = inum;
 736         } else {
 737                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 738                 cifs_autodisable_serverino(cifs_sb);
 739         }
 740
 741         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 742         tmp_dentry = cifs_readdir_lookup(file->f_dentry, &qstring, &fattr);
 743
 744         rc = filldir(direntry, qstring.name, qstring.len, file->f_pos,
 745                      ino, fattr.cf_dtype);
 746
 747         /*
 748          * we can not return filldir errors to the caller since they are
 749          * "normal" when the stat blocksize is too small - we return remapped
 750          * error instead
 751          *
 752          * FIXME: This looks bogus. filldir returns -EOVERFLOW in the above
 753          * case already. Why should we be clobbering other errors from it?
 754          */
 755         if (rc) {
 756                 cFYI(1, "filldir rc = %d", rc);
 757                 rc = -EOVERFLOW;
 758         }
 759         dput(tmp_dentry);
 760         return rc;
 761 }
 762
 763
 764 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 765 {
 766         int rc = 0;
 767         int xid, i;
 768         struct cifs_sb_info *cifs_sb;
 769         struct cifsTconInfo *pTcon;
 770         struct cifsFileInfo *cifsFile = NULL;
 771         char *current_entry;
 772         int num_to_fill = 0;
 773         char *tmp_buf = NULL;
 774         char *end_of_smb;
 775         unsigned int max_len;
 776
 777         xid = GetXid();
 778
 779         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 780         pTcon = cifs_sb->tcon;
 781         if (pTcon == NULL)
 782                 return -EINVAL;
 783
 784         switch ((int) file->f_pos) {
 785         case 0:
 786                 if (filldir(direntry, ".", 1, file->f_pos,
 787                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 788                         cERROR(1, "Filldir for current dir failed");
 789                         rc = -ENOMEM;
 790                         break;
 791                 }
 792                 file->f_pos++;
 793         case 1:
 794                 if (filldir(direntry, "..", 2, file->f_pos,
 795                      file->f_path.dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
 796                         cERROR(1, "Filldir for parent dir failed");
 797                         rc = -ENOMEM;
 798                         break;
 799                 }
 800                 file->f_pos++;
 801         default:
 802                 /* 1) If search is active,
 803                         is in current search buffer?
 804                         if it before then restart search
 805                         if after then keep searching till find it */
 806
 807                 if (file->private_data == NULL) {
 808                         rc = initiate_cifs_search(xid, file);
 809                         cFYI(1, "initiate cifs search rc %d", rc);
 810                         if (rc) {
 811                                 FreeXid(xid);
 812                                 return rc;
 813                         }
 814                 }
 815                 if (file->private_data == NULL) {
 816                         rc = -EINVAL;
 817                         FreeXid(xid);
 818                         return rc;
 819                 }
 820                 cifsFile = file->private_data;
 821                 if (cifsFile->srch_inf.endOfSearch) {
 822                         if (cifsFile->srch_inf.emptyDir) {
 823                                 cFYI(1, "End of search, empty dir");
 824                                 rc = 0;
 825                                 break;
 826                         }
 827                 } /* else {
 828                         cifsFile->invalidHandle = true;
 829                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 830                 } */
 831
 832                 rc = find_cifs_entry(xid, pTcon, file,
 833                                 &current_entry, &num_to_fill);
 834                 if (rc) {
 835                         cFYI(1, "fce error %d", rc);
 836                         goto rddir2_exit;
 837                 } else if (current_entry != NULL) {
 838                         cFYI(1, "entry %lld found", file->f_pos);
 839                 } else {
 840                         cFYI(1, "could not find entry");
 841                         goto rddir2_exit;
 842                 }
 843                 cFYI(1, "loop through %d times filling dir for net buf %p",
 844                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 845                 max_len = smbCalcSize((struct smb_hdr *)
 846                                 cifsFile->srch_inf.ntwrk_buf_start);
 847                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 848
 849                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 850                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 851                         if (current_entry == NULL) {
 852                                 /* evaluate whether this case is an error */
 853                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 854                                           num_to_fill, i);
 855                                 break;
 856                         }
 857                         /* if buggy server returns . and .. late do
 858                         we want to check for that here? */
 859                         rc = cifs_filldir(current_entry, file,
 860                                         filldir, direntry, tmp_buf, max_len);
 861                         if (rc == -EOVERFLOW) {
 862                                 rc = 0;
 863                                 break;
 864                         }
 865
 866                         file->f_pos++;
 867                         if (file->f_pos ==
 868                                 cifsFile->srch_inf.index_of_last_entry) {
 869                                 cFYI(1, "last entry in buf at pos %lld %s",
 870                                         file->f_pos, tmp_buf);
 871                                 cifs_save_resume_key(current_entry, cifsFile);
 872                                 break;
 873                         } else
 874                                 current_entry =
 875                                         nxt_dir_entry(current_entry, end_of_smb,
 876                                                 cifsFile->srch_inf.info_level);
 877                 }
 878                 kfree(tmp_buf);
 879                 break;
 880         } /* end switch */
 881
 882 rddir2_exit:
 883         FreeXid(xid);
 884         return rc;
 885 }