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_master_tcon(CIFS_SB(sb))->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_master_tcon(cifs_sb)->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(cifs_sb);
 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 = NULL;
 227         struct cifsFileInfo *cifsFile;
 228         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 229         struct tcon_link *tlink;
 230         struct cifsTconInfo *pTcon;
 231
 232         tlink = cifs_sb_tlink(cifs_sb);
 233         if (IS_ERR(tlink))
 234                 return PTR_ERR(tlink);
 235         pTcon = tlink_tcon(tlink);
 236
 237         if (file->private_data == NULL)
 238                 file->private_data =
 239                         kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 240         if (file->private_data == NULL) {
 241                 rc = -ENOMEM;
 242                 goto error_exit;
 243         }
 244
 245         cifsFile = file->private_data;
 246         cifsFile->invalidHandle = true;
 247         cifsFile->srch_inf.endOfSearch = false;
 248         cifsFile->tlink = cifs_get_tlink(tlink);
 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(char *str)
 295 {
 296         int len;
 297         __le16 *ustr = (__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 #define UNICODE_DOT cpu_to_le16(0x2e)
 339
 340 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 341 static int cifs_entry_is_dot(char *current_entry, struct cifsFileInfo *cfile)
 342 {
 343         int rc = 0;
 344         char *filename = NULL;
 345         int len = 0;
 346
 347         if (cfile->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
 348                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 349                 filename = &pFindData->FileName[0];
 350                 if (cfile->srch_inf.unicode) {
 351                         len = cifs_unicode_bytelen(filename);
 352                 } else {
 353                         /* BB should we make this strnlen of PATH_MAX? */
 354                         len = strnlen(filename, 5);
 355                 }
 356         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_DIRECTORY_INFO) {
 357                 FILE_DIRECTORY_INFO *pFindData =
 358                         (FILE_DIRECTORY_INFO *)current_entry;
 359                 filename = &pFindData->FileName[0];
 360                 len = le32_to_cpu(pFindData->FileNameLength);
 361         } else if (cfile->srch_inf.info_level ==
 362                         SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 363                 FILE_FULL_DIRECTORY_INFO *pFindData =
 364                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 365                 filename = &pFindData->FileName[0];
 366                 len = le32_to_cpu(pFindData->FileNameLength);
 367         } else if (cfile->srch_inf.info_level ==
 368                         SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 369                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 370                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 371                 filename = &pFindData->FileName[0];
 372                 len = le32_to_cpu(pFindData->FileNameLength);
 373         } else if (cfile->srch_inf.info_level ==
 374                         SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 375                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 376                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 377                 filename = &pFindData->FileName[0];
 378                 len = le32_to_cpu(pFindData->FileNameLength);
 379         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD) {
 380                 FIND_FILE_STANDARD_INFO *pFindData =
 381                         (FIND_FILE_STANDARD_INFO *)current_entry;
 382                 filename = &pFindData->FileName[0];
 383                 len = pFindData->FileNameLength;
 384         } else {
 385                 cFYI(1, "Unknown findfirst level %d",
 386                          cfile->srch_inf.info_level);
 387         }
 388
 389         if (filename) {
 390                 if (cfile->srch_inf.unicode) {
 391                         __le16 *ufilename = (__le16 *)filename;
 392                         if (len == 2) {
 393                                 /* check for . */
 394                                 if (ufilename[0] == UNICODE_DOT)
 395                                         rc = 1;
 396                         } else if (len == 4) {
 397                                 /* check for .. */
 398                                 if ((ufilename[0] == UNICODE_DOT)
 399                                    && (ufilename[1] == UNICODE_DOT))
 400                                         rc = 2;
 401                         }
 402                 } else /* ASCII */ {
 403                         if (len == 1) {
 404                                 if (filename[0] == '.')
 405                                         rc = 1;
 406                         } else if (len == 2) {
 407                                 if ((filename[0] == '.') && (filename[1] == '.'))
 408                                         rc = 2;
 409                         }
 410                 }
 411         }
 412
 413         return rc;
 414 }
 415
 416 /* Check if directory that we are searching has changed so we can decide
 417    whether we can use the cached search results from the previous search */
 418 static int is_dir_changed(struct file *file)
 419 {
 420         struct inode *inode = file->f_path.dentry->d_inode;
 421         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 422
 423         if (cifsInfo->time == 0)
 424                 return 1; /* directory was changed, perhaps due to unlink */
 425         else
 426                 return 0;
 427
 428 }
 429
 430 static int cifs_save_resume_key(const char *current_entry,
 431         struct cifsFileInfo *cifsFile)
 432 {
 433         int rc = 0;
 434         unsigned int len = 0;
 435         __u16 level;
 436         char *filename;
 437
 438         if ((cifsFile == NULL) || (current_entry == NULL))
 439                 return -EINVAL;
 440
 441         level = cifsFile->srch_inf.info_level;
 442
 443         if (level == SMB_FIND_FILE_UNIX) {
 444                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 445
 446                 filename = &pFindData->FileName[0];
 447                 if (cifsFile->srch_inf.unicode) {
 448                         len = cifs_unicode_bytelen(filename);
 449                 } else {
 450                         /* BB should we make this strnlen of PATH_MAX? */
 451                         len = strnlen(filename, PATH_MAX);
 452                 }
 453                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 454         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 455                 FILE_DIRECTORY_INFO *pFindData =
 456                         (FILE_DIRECTORY_INFO *)current_entry;
 457                 filename = &pFindData->FileName[0];
 458                 len = le32_to_cpu(pFindData->FileNameLength);
 459                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 460         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 461                 FILE_FULL_DIRECTORY_INFO *pFindData =
 462                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 463                 filename = &pFindData->FileName[0];
 464                 len = le32_to_cpu(pFindData->FileNameLength);
 465                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 466         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 467                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 468                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 469                 filename = &pFindData->FileName[0];
 470                 len = le32_to_cpu(pFindData->FileNameLength);
 471                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 472         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 473                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 474                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 475                 filename = &pFindData->FileName[0];
 476                 len = le32_to_cpu(pFindData->FileNameLength);
 477                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 478         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 479                 FIND_FILE_STANDARD_INFO *pFindData =
 480                         (FIND_FILE_STANDARD_INFO *)current_entry;
 481                 filename = &pFindData->FileName[0];
 482                 /* one byte length, no name conversion */
 483                 len = (unsigned int)pFindData->FileNameLength;
 484                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 485         } else {
 486                 cFYI(1, "Unknown findfirst level %d", level);
 487                 return -EINVAL;
 488         }
 489         cifsFile->srch_inf.resume_name_len = len;
 490         cifsFile->srch_inf.presume_name = filename;
 491         return rc;
 492 }
 493
 494 /* find the corresponding entry in the search */
 495 /* Note that the SMB server returns search entries for . and .. which
 496    complicates logic here if we choose to parse for them and we do not
 497    assume that they are located in the findfirst return buffer.*/
 498 /* We start counting in the buffer with entry 2 and increment for every
 499    entry (do not increment for . or .. entry) */
 500 static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
 501         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 502 {
 503         int rc = 0;
 504         int pos_in_buf = 0;
 505         loff_t first_entry_in_buffer;
 506         loff_t index_to_find = file->f_pos;
 507         struct cifsFileInfo *cifsFile = file->private_data;
 508         /* check if index in the buffer */
 509
 510         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 511            (num_to_ret == NULL))
 512                 return -ENOENT;
 513
 514         *ppCurrentEntry = NULL;
 515         first_entry_in_buffer =
 516                 cifsFile->srch_inf.index_of_last_entry -
 517                         cifsFile->srch_inf.entries_in_buffer;
 518
 519         /* if first entry in buf is zero then is first buffer
 520         in search response data which means it is likely . and ..
 521         will be in this buffer, although some servers do not return
 522         . and .. for the root of a drive and for those we need
 523         to start two entries earlier */
 524
 525         dump_cifs_file_struct(file, "In fce ");
 526         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 527              is_dir_changed(file)) ||
 528            (index_to_find < first_entry_in_buffer)) {
 529                 /* close and restart search */
 530                 cFYI(1, "search backing up - close and restart search");
 531                 write_lock(&GlobalSMBSeslock);
 532                 if (!cifsFile->srch_inf.endOfSearch &&
 533                     !cifsFile->invalidHandle) {
 534                         cifsFile->invalidHandle = true;
 535                         write_unlock(&GlobalSMBSeslock);
 536                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 537                 } else
 538                         write_unlock(&GlobalSMBSeslock);
 539                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 540                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 541                         if (cifsFile->srch_inf.smallBuf)
 542                                 cifs_small_buf_release(cifsFile->srch_inf.
 543                                                 ntwrk_buf_start);
 544                         else
 545                                 cifs_buf_release(cifsFile->srch_inf.
 546                                                 ntwrk_buf_start);
 547                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 548                 }
 549                 rc = initiate_cifs_search(xid, file);
 550                 if (rc) {
 551                         cFYI(1, "error %d reinitiating a search on rewind",
 552                                  rc);
 553                         return rc;
 554                 }
 555                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 556         }
 557
 558         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 559               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 560                 cFYI(1, "calling findnext2");
 561                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
 562                                   &cifsFile->srch_inf);
 563                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 564                 if (rc)
 565                         return -ENOENT;
 566         }
 567         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 568                 /* we found the buffer that contains the entry */
 569                 /* scan and find it */
 570                 int i;
 571                 char *current_entry;
 572                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 573                         smbCalcSize((struct smb_hdr *)
 574                                 cifsFile->srch_inf.ntwrk_buf_start);
 575
 576                 current_entry = cifsFile->srch_inf.srch_entries_start;
 577                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 578                                         - cifsFile->srch_inf.entries_in_buffer;
 579                 pos_in_buf = index_to_find - first_entry_in_buffer;
 580                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 581
 582                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 583                         /* go entry by entry figuring out which is first */
 584                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 585                                                 cifsFile->srch_inf.info_level);
 586                 }
 587                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 588                         /* BB fixme - check if we should flag this error */
 589                         cERROR(1, "reached end of buf searching for pos in buf"
 590                           " %d index to find %lld rc %d",
 591                           pos_in_buf, index_to_find, rc);
 592                 }
 593                 rc = 0;
 594                 *ppCurrentEntry = current_entry;
 595         } else {
 596                 cFYI(1, "index not in buffer - could not findnext into it");
 597                 return 0;
 598         }
 599
 600         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 601                 cFYI(1, "can not return entries pos_in_buf beyond last");
 602                 *num_to_ret = 0;
 603         } else
 604                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 605
 606         return rc;
 607 }
 608
 609 /* inode num, inode type and filename returned */
 610 static int cifs_get_name_from_search_buf(struct qstr *pqst,
 611         char *current_entry, __u16 level, unsigned int unicode,
 612         struct cifs_sb_info *cifs_sb, unsigned int max_len, __u64 *pinum)
 613 {
 614         int rc = 0;
 615         unsigned int len = 0;
 616         char *filename;
 617         struct nls_table *nlt = cifs_sb->local_nls;
 618
 619         *pinum = 0;
 620
 621         if (level == SMB_FIND_FILE_UNIX) {
 622                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 623
 624                 filename = &pFindData->FileName[0];
 625                 if (unicode) {
 626                         len = cifs_unicode_bytelen(filename);
 627                 } else {
 628                         /* BB should we make this strnlen of PATH_MAX? */
 629                         len = strnlen(filename, PATH_MAX);
 630                 }
 631
 632                 *pinum = le64_to_cpu(pFindData->basic.UniqueId);
 633         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 634                 FILE_DIRECTORY_INFO *pFindData =
 635                         (FILE_DIRECTORY_INFO *)current_entry;
 636                 filename = &pFindData->FileName[0];
 637                 len = le32_to_cpu(pFindData->FileNameLength);
 638         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 639                 FILE_FULL_DIRECTORY_INFO *pFindData =
 640                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 641                 filename = &pFindData->FileName[0];
 642                 len = le32_to_cpu(pFindData->FileNameLength);
 643         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 644                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 645                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 646                 filename = &pFindData->FileName[0];
 647                 len = le32_to_cpu(pFindData->FileNameLength);
 648                 *pinum = le64_to_cpu(pFindData->UniqueId);
 649         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 650                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 651                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 652                 filename = &pFindData->FileName[0];
 653                 len = le32_to_cpu(pFindData->FileNameLength);
 654         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 655                 FIND_FILE_STANDARD_INFO *pFindData =
 656                         (FIND_FILE_STANDARD_INFO *)current_entry;
 657                 filename = &pFindData->FileName[0];
 658                 /* one byte length, no name conversion */
 659                 len = (unsigned int)pFindData->FileNameLength;
 660         } else {
 661                 cFYI(1, "Unknown findfirst level %d", level);
 662                 return -EINVAL;
 663         }
 664
 665         if (len > max_len) {
 666                 cERROR(1, "bad search response length %d past smb end", len);
 667                 return -EINVAL;
 668         }
 669
 670         if (unicode) {
 671                 pqst->len = cifs_from_ucs2((char *) pqst->name,
 672                                            (__le16 *) filename,
 673                                            UNICODE_NAME_MAX,
 674                                            min(len, max_len), nlt,
 675                                            cifs_sb->mnt_cifs_flags &
 676                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 677                 pqst->len -= nls_nullsize(nlt);
 678         } else {
 679                 pqst->name = filename;
 680                 pqst->len = len;
 681         }
 682         return rc;
 683 }
 684
 685 static int cifs_filldir(char *pfindEntry, struct file *file, filldir_t filldir,
 686                         void *direntry, char *scratch_buf, unsigned int max_len)
 687 {
 688         int rc = 0;
 689         struct qstr qstring;
 690         struct cifsFileInfo *pCifsF;
 691         u64    inum;
 692         ino_t  ino;
 693         struct super_block *sb;
 694         struct cifs_sb_info *cifs_sb;
 695         struct dentry *tmp_dentry;
 696         struct cifs_fattr fattr;
 697
 698         /* get filename and len into qstring */
 699         /* get dentry */
 700         /* decide whether to create and populate ionde */
 701         if ((direntry == NULL) || (file == NULL))
 702                 return -EINVAL;
 703
 704         pCifsF = file->private_data;
 705
 706         if ((scratch_buf == NULL) || (pfindEntry == NULL) || (pCifsF == NULL))
 707                 return -ENOENT;
 708
 709         rc = cifs_entry_is_dot(pfindEntry, pCifsF);
 710         /* skip . and .. since we added them first */
 711         if (rc != 0)
 712                 return 0;
 713
 714         sb = file->f_path.dentry->d_sb;
 715         cifs_sb = CIFS_SB(sb);
 716
 717         qstring.name = scratch_buf;
 718         rc = cifs_get_name_from_search_buf(&qstring, pfindEntry,
 719                         pCifsF->srch_inf.info_level,
 720                         pCifsF->srch_inf.unicode, cifs_sb,
 721                         max_len, &inum /* returned */);
 722
 723         if (rc)
 724                 return rc;
 725
 726         if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX)
 727                 cifs_unix_basic_to_fattr(&fattr,
 728                                  &((FILE_UNIX_INFO *) pfindEntry)->basic,
 729                                  cifs_sb);
 730         else if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD)
 731                 cifs_std_info_to_fattr(&fattr, (FIND_FILE_STANDARD_INFO *)
 732                                         pfindEntry, cifs_sb);
 733         else
 734                 cifs_dir_info_to_fattr(&fattr, (FILE_DIRECTORY_INFO *)
 735                                         pfindEntry, cifs_sb);
 736
 737         if (inum && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 738                 fattr.cf_uniqueid = inum;
 739         } else {
 740                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 741                 cifs_autodisable_serverino(cifs_sb);
 742         }
 743
 744         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 745             CIFSCouldBeMFSymlink(&fattr))
 746                 /*
 747                  * trying to get the type and mode can be slow,
 748                  * so just call those regular files for now, and mark
 749                  * for reval
 750                  */
 751                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 752
 753         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 754         tmp_dentry = cifs_readdir_lookup(file->f_dentry, &qstring, &fattr);
 755
 756         rc = filldir(direntry, qstring.name, qstring.len, file->f_pos,
 757                      ino, fattr.cf_dtype);
 758
 759         /*
 760          * we can not return filldir errors to the caller since they are
 761          * "normal" when the stat blocksize is too small - we return remapped
 762          * error instead
 763          *
 764          * FIXME: This looks bogus. filldir returns -EOVERFLOW in the above
 765          * case already. Why should we be clobbering other errors from it?
 766          */
 767         if (rc) {
 768                 cFYI(1, "filldir rc = %d", rc);
 769                 rc = -EOVERFLOW;
 770         }
 771         dput(tmp_dentry);
 772         return rc;
 773 }
 774
 775
 776 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 777 {
 778         int rc = 0;
 779         int xid, i;
 780         struct cifs_sb_info *cifs_sb;
 781         struct cifsTconInfo *pTcon;
 782         struct cifsFileInfo *cifsFile = NULL;
 783         char *current_entry;
 784         int num_to_fill = 0;
 785         char *tmp_buf = NULL;
 786         char *end_of_smb;
 787         unsigned int max_len;
 788
 789         xid = GetXid();
 790
 791         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 792
 793         /*
 794          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 795          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 796          */
 797         if (file->private_data == NULL) {
 798                 rc = initiate_cifs_search(xid, file);
 799                 cFYI(1, "initiate cifs search rc %d", rc);
 800                 if (rc)
 801                         goto rddir2_exit;
 802         }
 803
 804         switch ((int) file->f_pos) {
 805         case 0:
 806                 if (filldir(direntry, ".", 1, file->f_pos,
 807                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 808                         cERROR(1, "Filldir for current dir failed");
 809                         rc = -ENOMEM;
 810                         break;
 811                 }
 812                 file->f_pos++;
 813         case 1:
 814                 if (filldir(direntry, "..", 2, file->f_pos,
 815                      file->f_path.dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
 816                         cERROR(1, "Filldir for parent dir failed");
 817                         rc = -ENOMEM;
 818                         break;
 819                 }
 820                 file->f_pos++;
 821         default:
 822                 /* 1) If search is active,
 823                         is in current search buffer?
 824                         if it before then restart search
 825                         if after then keep searching till find it */
 826
 827                 if (file->private_data == NULL) {
 828                         rc = -EINVAL;
 829                         FreeXid(xid);
 830                         return rc;
 831                 }
 832                 cifsFile = file->private_data;
 833                 if (cifsFile->srch_inf.endOfSearch) {
 834                         if (cifsFile->srch_inf.emptyDir) {
 835                                 cFYI(1, "End of search, empty dir");
 836                                 rc = 0;
 837                                 break;
 838                         }
 839                 } /* else {
 840                         cifsFile->invalidHandle = true;
 841                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 842                 } */
 843
 844                 pTcon = tlink_tcon(cifsFile->tlink);
 845                 rc = find_cifs_entry(xid, pTcon, file,
 846                                 &current_entry, &num_to_fill);
 847                 if (rc) {
 848                         cFYI(1, "fce error %d", rc);
 849                         goto rddir2_exit;
 850                 } else if (current_entry != NULL) {
 851                         cFYI(1, "entry %lld found", file->f_pos);
 852                 } else {
 853                         cFYI(1, "could not find entry");
 854                         goto rddir2_exit;
 855                 }
 856                 cFYI(1, "loop through %d times filling dir for net buf %p",
 857                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 858                 max_len = smbCalcSize((struct smb_hdr *)
 859                                 cifsFile->srch_inf.ntwrk_buf_start);
 860                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 861
 862                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 863                 if (tmp_buf == NULL) {
 864                         rc = -ENOMEM;
 865                         break;
 866                 }
 867
 868                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 869                         if (current_entry == NULL) {
 870                                 /* evaluate whether this case is an error */
 871                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 872                                           num_to_fill, i);
 873                                 break;
 874                         }
 875                         /* if buggy server returns . and .. late do
 876                         we want to check for that here? */
 877                         rc = cifs_filldir(current_entry, file,
 878                                         filldir, direntry, tmp_buf, max_len);
 879                         if (rc == -EOVERFLOW) {
 880                                 rc = 0;
 881                                 break;
 882                         }
 883
 884                         file->f_pos++;
 885                         if (file->f_pos ==
 886                                 cifsFile->srch_inf.index_of_last_entry) {
 887                                 cFYI(1, "last entry in buf at pos %lld %s",
 888                                         file->f_pos, tmp_buf);
 889                                 cifs_save_resume_key(current_entry, cifsFile);
 890                                 break;
 891                         } else
 892                                 current_entry =
 893                                         nxt_dir_entry(current_entry, end_of_smb,
 894                                                 cifsFile->srch_inf.info_level);
 895                 }
 896                 kfree(tmp_buf);
 897                 break;
 898         } /* end switch */
 899
 900 rddir2_exit:
 901         FreeXid(xid);
 902         return rc;
 903 }