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         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 232         if (cifs_sb == NULL)
 233                 return -EINVAL;
 234
 235         if (file->private_data == NULL)
 236                 file->private_data =
 237                         kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 238
 239         if (file->private_data == NULL)
 240                 return -ENOMEM;
 241         cifsFile = file->private_data;
 242         cifsFile->invalidHandle = true;
 243         cifsFile->srch_inf.endOfSearch = false;
 244         cifsFile->tcon = cifs_sb->tcon;
 245         pTcon = cifsFile->tcon;
 246         if (pTcon == NULL)
 247                 return -EINVAL;
 248
 249         full_path = build_path_from_dentry(file->f_path.dentry);
 250
 251         if (full_path == NULL)
 252                 return -ENOMEM;
 253
 254         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 255
 256 ffirst_retry:
 257         /* test for Unix extensions */
 258         /* but now check for them on the share/mount not on the SMB session */
 259 /*      if (pTcon->ses->capabilities & CAP_UNIX) { */
 260         if (pTcon->unix_ext)
 261                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 262         else if ((pTcon->ses->capabilities &
 263                         (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
 264                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 265         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 266                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 267         } else /* not srvinos - BB fixme add check for backlevel? */ {
 268                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 269         }
 270
 271         rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
 272                 &cifsFile->netfid, &cifsFile->srch_inf,
 273                 cifs_sb->mnt_cifs_flags &
 274                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
 275         if (rc == 0)
 276                 cifsFile->invalidHandle = false;
 277         /* BB add following call to handle readdir on new NTFS symlink errors
 278         else if STATUS_STOPPED_ON_SYMLINK
 279                 call get_symlink_reparse_path and retry with new path */
 280         else if ((rc == -EOPNOTSUPP) &&
 281                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 282                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 283                 goto ffirst_retry;
 284         }
 285         kfree(full_path);
 286         return rc;
 287 }
 288
 289 /* return length of unicode string in bytes */
 290 static int cifs_unicode_bytelen(char *str)
 291 {
 292         int len;
 293         __le16 *ustr = (__le16 *)str;
 294
 295         for (len = 0; len <= PATH_MAX; len++) {
 296                 if (ustr[len] == 0)
 297                         return len << 1;
 298         }
 299         cFYI(1, "Unicode string longer than PATH_MAX found");
 300         return len << 1;
 301 }
 302
 303 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 304 {
 305         char *new_entry;
 306         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 307
 308         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 309                 FIND_FILE_STANDARD_INFO *pfData;
 310                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 311
 312                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 313                                 pfData->FileNameLength;
 314         } else
 315                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 316         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 317         /* validate that new_entry is not past end of SMB */
 318         if (new_entry >= end_of_smb) {
 319                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 320                         new_entry, end_of_smb, old_entry);
 321                 return NULL;
 322         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 323                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 324                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 325                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 326                 cERROR(1, "search entry %p extends after end of SMB %p",
 327                         new_entry, end_of_smb);
 328                 return NULL;
 329         } else
 330                 return new_entry;
 331
 332 }
 333
 334 #define UNICODE_DOT cpu_to_le16(0x2e)
 335
 336 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 337 static int cifs_entry_is_dot(char *current_entry, struct cifsFileInfo *cfile)
 338 {
 339         int rc = 0;
 340         char *filename = NULL;
 341         int len = 0;
 342
 343         if (cfile->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
 344                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 345                 filename = &pFindData->FileName[0];
 346                 if (cfile->srch_inf.unicode) {
 347                         len = cifs_unicode_bytelen(filename);
 348                 } else {
 349                         /* BB should we make this strnlen of PATH_MAX? */
 350                         len = strnlen(filename, 5);
 351                 }
 352         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_DIRECTORY_INFO) {
 353                 FILE_DIRECTORY_INFO *pFindData =
 354                         (FILE_DIRECTORY_INFO *)current_entry;
 355                 filename = &pFindData->FileName[0];
 356                 len = le32_to_cpu(pFindData->FileNameLength);
 357         } else if (cfile->srch_inf.info_level ==
 358                         SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 359                 FILE_FULL_DIRECTORY_INFO *pFindData =
 360                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 361                 filename = &pFindData->FileName[0];
 362                 len = le32_to_cpu(pFindData->FileNameLength);
 363         } else if (cfile->srch_inf.info_level ==
 364                         SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 365                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 366                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 367                 filename = &pFindData->FileName[0];
 368                 len = le32_to_cpu(pFindData->FileNameLength);
 369         } else if (cfile->srch_inf.info_level ==
 370                         SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 371                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 372                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 373                 filename = &pFindData->FileName[0];
 374                 len = le32_to_cpu(pFindData->FileNameLength);
 375         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD) {
 376                 FIND_FILE_STANDARD_INFO *pFindData =
 377                         (FIND_FILE_STANDARD_INFO *)current_entry;
 378                 filename = &pFindData->FileName[0];
 379                 len = pFindData->FileNameLength;
 380         } else {
 381                 cFYI(1, "Unknown findfirst level %d",
 382                          cfile->srch_inf.info_level);
 383         }
 384
 385         if (filename) {
 386                 if (cfile->srch_inf.unicode) {
 387                         __le16 *ufilename = (__le16 *)filename;
 388                         if (len == 2) {
 389                                 /* check for . */
 390                                 if (ufilename[0] == UNICODE_DOT)
 391                                         rc = 1;
 392                         } else if (len == 4) {
 393                                 /* check for .. */
 394                                 if ((ufilename[0] == UNICODE_DOT)
 395                                    && (ufilename[1] == UNICODE_DOT))
 396                                         rc = 2;
 397                         }
 398                 } else /* ASCII */ {
 399                         if (len == 1) {
 400                                 if (filename[0] == '.')
 401                                         rc = 1;
 402                         } else if (len == 2) {
 403                                 if ((filename[0] == '.') && (filename[1] == '.'))
 404                                         rc = 2;
 405                         }
 406                 }
 407         }
 408
 409         return rc;
 410 }
 411
 412 /* Check if directory that we are searching has changed so we can decide
 413    whether we can use the cached search results from the previous search */
 414 static int is_dir_changed(struct file *file)
 415 {
 416         struct inode *inode = file->f_path.dentry->d_inode;
 417         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 418
 419         if (cifsInfo->time == 0)
 420                 return 1; /* directory was changed, perhaps due to unlink */
 421         else
 422                 return 0;
 423
 424 }
 425
 426 static int cifs_save_resume_key(const char *current_entry,
 427         struct cifsFileInfo *cifsFile)
 428 {
 429         int rc = 0;
 430         unsigned int len = 0;
 431         __u16 level;
 432         char *filename;
 433
 434         if ((cifsFile == NULL) || (current_entry == NULL))
 435                 return -EINVAL;
 436
 437         level = cifsFile->srch_inf.info_level;
 438
 439         if (level == SMB_FIND_FILE_UNIX) {
 440                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 441
 442                 filename = &pFindData->FileName[0];
 443                 if (cifsFile->srch_inf.unicode) {
 444                         len = cifs_unicode_bytelen(filename);
 445                 } else {
 446                         /* BB should we make this strnlen of PATH_MAX? */
 447                         len = strnlen(filename, PATH_MAX);
 448                 }
 449                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 450         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 451                 FILE_DIRECTORY_INFO *pFindData =
 452                         (FILE_DIRECTORY_INFO *)current_entry;
 453                 filename = &pFindData->FileName[0];
 454                 len = le32_to_cpu(pFindData->FileNameLength);
 455                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 456         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 457                 FILE_FULL_DIRECTORY_INFO *pFindData =
 458                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 459                 filename = &pFindData->FileName[0];
 460                 len = le32_to_cpu(pFindData->FileNameLength);
 461                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 462         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 463                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 464                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 465                 filename = &pFindData->FileName[0];
 466                 len = le32_to_cpu(pFindData->FileNameLength);
 467                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 468         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 469                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 470                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 471                 filename = &pFindData->FileName[0];
 472                 len = le32_to_cpu(pFindData->FileNameLength);
 473                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 474         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 475                 FIND_FILE_STANDARD_INFO *pFindData =
 476                         (FIND_FILE_STANDARD_INFO *)current_entry;
 477                 filename = &pFindData->FileName[0];
 478                 /* one byte length, no name conversion */
 479                 len = (unsigned int)pFindData->FileNameLength;
 480                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 481         } else {
 482                 cFYI(1, "Unknown findfirst level %d", level);
 483                 return -EINVAL;
 484         }
 485         cifsFile->srch_inf.resume_name_len = len;
 486         cifsFile->srch_inf.presume_name = filename;
 487         return rc;
 488 }
 489
 490 /* find the corresponding entry in the search */
 491 /* Note that the SMB server returns search entries for . and .. which
 492    complicates logic here if we choose to parse for them and we do not
 493    assume that they are located in the findfirst return buffer.*/
 494 /* We start counting in the buffer with entry 2 and increment for every
 495    entry (do not increment for . or .. entry) */
 496 static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
 497         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 498 {
 499         int rc = 0;
 500         int pos_in_buf = 0;
 501         loff_t first_entry_in_buffer;
 502         loff_t index_to_find = file->f_pos;
 503         struct cifsFileInfo *cifsFile = file->private_data;
 504         /* check if index in the buffer */
 505
 506         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 507            (num_to_ret == NULL))
 508                 return -ENOENT;
 509
 510         *ppCurrentEntry = NULL;
 511         first_entry_in_buffer =
 512                 cifsFile->srch_inf.index_of_last_entry -
 513                         cifsFile->srch_inf.entries_in_buffer;
 514
 515         /* if first entry in buf is zero then is first buffer
 516         in search response data which means it is likely . and ..
 517         will be in this buffer, although some servers do not return
 518         . and .. for the root of a drive and for those we need
 519         to start two entries earlier */
 520
 521         dump_cifs_file_struct(file, "In fce ");
 522         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 523              is_dir_changed(file)) ||
 524            (index_to_find < first_entry_in_buffer)) {
 525                 /* close and restart search */
 526                 cFYI(1, "search backing up - close and restart search");
 527                 write_lock(&GlobalSMBSeslock);
 528                 if (!cifsFile->srch_inf.endOfSearch &&
 529                     !cifsFile->invalidHandle) {
 530                         cifsFile->invalidHandle = true;
 531                         write_unlock(&GlobalSMBSeslock);
 532                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 533                 } else
 534                         write_unlock(&GlobalSMBSeslock);
 535                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 536                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 537                         if (cifsFile->srch_inf.smallBuf)
 538                                 cifs_small_buf_release(cifsFile->srch_inf.
 539                                                 ntwrk_buf_start);
 540                         else
 541                                 cifs_buf_release(cifsFile->srch_inf.
 542                                                 ntwrk_buf_start);
 543                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 544                 }
 545                 rc = initiate_cifs_search(xid, file);
 546                 if (rc) {
 547                         cFYI(1, "error %d reinitiating a search on rewind",
 548                                  rc);
 549                         return rc;
 550                 }
 551                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 552         }
 553
 554         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 555               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 556                 cFYI(1, "calling findnext2");
 557                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
 558                                   &cifsFile->srch_inf);
 559                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 560                 if (rc)
 561                         return -ENOENT;
 562         }
 563         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 564                 /* we found the buffer that contains the entry */
 565                 /* scan and find it */
 566                 int i;
 567                 char *current_entry;
 568                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 569                         smbCalcSize((struct smb_hdr *)
 570                                 cifsFile->srch_inf.ntwrk_buf_start);
 571
 572                 current_entry = cifsFile->srch_inf.srch_entries_start;
 573                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 574                                         - cifsFile->srch_inf.entries_in_buffer;
 575                 pos_in_buf = index_to_find - first_entry_in_buffer;
 576                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 577
 578                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 579                         /* go entry by entry figuring out which is first */
 580                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 581                                                 cifsFile->srch_inf.info_level);
 582                 }
 583                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 584                         /* BB fixme - check if we should flag this error */
 585                         cERROR(1, "reached end of buf searching for pos in buf"
 586                           " %d index to find %lld rc %d",
 587                           pos_in_buf, index_to_find, rc);
 588                 }
 589                 rc = 0;
 590                 *ppCurrentEntry = current_entry;
 591         } else {
 592                 cFYI(1, "index not in buffer - could not findnext into it");
 593                 return 0;
 594         }
 595
 596         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 597                 cFYI(1, "can not return entries pos_in_buf beyond last");
 598                 *num_to_ret = 0;
 599         } else
 600                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 601
 602         return rc;
 603 }
 604
 605 /* inode num, inode type and filename returned */
 606 static int cifs_get_name_from_search_buf(struct qstr *pqst,
 607         char *current_entry, __u16 level, unsigned int unicode,
 608         struct cifs_sb_info *cifs_sb, unsigned int max_len, __u64 *pinum)
 609 {
 610         int rc = 0;
 611         unsigned int len = 0;
 612         char *filename;
 613         struct nls_table *nlt = cifs_sb->local_nls;
 614
 615         *pinum = 0;
 616
 617         if (level == SMB_FIND_FILE_UNIX) {
 618                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 619
 620                 filename = &pFindData->FileName[0];
 621                 if (unicode) {
 622                         len = cifs_unicode_bytelen(filename);
 623                 } else {
 624                         /* BB should we make this strnlen of PATH_MAX? */
 625                         len = strnlen(filename, PATH_MAX);
 626                 }
 627
 628                 *pinum = le64_to_cpu(pFindData->basic.UniqueId);
 629         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 630                 FILE_DIRECTORY_INFO *pFindData =
 631                         (FILE_DIRECTORY_INFO *)current_entry;
 632                 filename = &pFindData->FileName[0];
 633                 len = le32_to_cpu(pFindData->FileNameLength);
 634         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 635                 FILE_FULL_DIRECTORY_INFO *pFindData =
 636                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 637                 filename = &pFindData->FileName[0];
 638                 len = le32_to_cpu(pFindData->FileNameLength);
 639         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 640                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 641                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 642                 filename = &pFindData->FileName[0];
 643                 len = le32_to_cpu(pFindData->FileNameLength);
 644                 *pinum = le64_to_cpu(pFindData->UniqueId);
 645         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 646                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 647                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 648                 filename = &pFindData->FileName[0];
 649                 len = le32_to_cpu(pFindData->FileNameLength);
 650         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 651                 FIND_FILE_STANDARD_INFO *pFindData =
 652                         (FIND_FILE_STANDARD_INFO *)current_entry;
 653                 filename = &pFindData->FileName[0];
 654                 /* one byte length, no name conversion */
 655                 len = (unsigned int)pFindData->FileNameLength;
 656         } else {
 657                 cFYI(1, "Unknown findfirst level %d", level);
 658                 return -EINVAL;
 659         }
 660
 661         if (len > max_len) {
 662                 cERROR(1, "bad search response length %d past smb end", len);
 663                 return -EINVAL;
 664         }
 665
 666         if (unicode) {
 667                 pqst->len = cifs_from_ucs2((char *) pqst->name,
 668                                            (__le16 *) filename,
 669                                            UNICODE_NAME_MAX,
 670                                            min(len, max_len), nlt,
 671                                            cifs_sb->mnt_cifs_flags &
 672                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 673                 pqst->len -= nls_nullsize(nlt);
 674         } else {
 675                 pqst->name = filename;
 676                 pqst->len = len;
 677         }
 678         return rc;
 679 }
 680
 681 static int cifs_filldir(char *pfindEntry, struct file *file, filldir_t filldir,
 682                         void *direntry, char *scratch_buf, unsigned int max_len)
 683 {
 684         int rc = 0;
 685         struct qstr qstring;
 686         struct cifsFileInfo *pCifsF;
 687         u64    inum;
 688         ino_t  ino;
 689         struct super_block *sb;
 690         struct cifs_sb_info *cifs_sb;
 691         struct dentry *tmp_dentry;
 692         struct cifs_fattr fattr;
 693
 694         /* get filename and len into qstring */
 695         /* get dentry */
 696         /* decide whether to create and populate ionde */
 697         if ((direntry == NULL) || (file == NULL))
 698                 return -EINVAL;
 699
 700         pCifsF = file->private_data;
 701
 702         if ((scratch_buf == NULL) || (pfindEntry == NULL) || (pCifsF == NULL))
 703                 return -ENOENT;
 704
 705         rc = cifs_entry_is_dot(pfindEntry, pCifsF);
 706         /* skip . and .. since we added them first */
 707         if (rc != 0)
 708                 return 0;
 709
 710         sb = file->f_path.dentry->d_sb;
 711         cifs_sb = CIFS_SB(sb);
 712
 713         qstring.name = scratch_buf;
 714         rc = cifs_get_name_from_search_buf(&qstring, pfindEntry,
 715                         pCifsF->srch_inf.info_level,
 716                         pCifsF->srch_inf.unicode, cifs_sb,
 717                         max_len, &inum /* returned */);
 718
 719         if (rc)
 720                 return rc;
 721
 722         if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX)
 723                 cifs_unix_basic_to_fattr(&fattr,
 724                                  &((FILE_UNIX_INFO *) pfindEntry)->basic,
 725                                  cifs_sb);
 726         else if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD)
 727                 cifs_std_info_to_fattr(&fattr, (FIND_FILE_STANDARD_INFO *)
 728                                         pfindEntry, cifs_sb);
 729         else
 730                 cifs_dir_info_to_fattr(&fattr, (FILE_DIRECTORY_INFO *)
 731                                         pfindEntry, cifs_sb);
 732
 733         if (inum && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 734                 fattr.cf_uniqueid = inum;
 735         } else {
 736                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 737                 cifs_autodisable_serverino(cifs_sb);
 738         }
 739
 740         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 741             CIFSCouldBeMFSymlink(&fattr))
 742                 /*
 743                  * trying to get the type and mode can be slow,
 744                  * so just call those regular files for now, and mark
 745                  * for reval
 746                  */
 747                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 748
 749         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 750         tmp_dentry = cifs_readdir_lookup(file->f_dentry, &qstring, &fattr);
 751
 752         rc = filldir(direntry, qstring.name, qstring.len, file->f_pos,
 753                      ino, fattr.cf_dtype);
 754
 755         /*
 756          * we can not return filldir errors to the caller since they are
 757          * "normal" when the stat blocksize is too small - we return remapped
 758          * error instead
 759          *
 760          * FIXME: This looks bogus. filldir returns -EOVERFLOW in the above
 761          * case already. Why should we be clobbering other errors from it?
 762          */
 763         if (rc) {
 764                 cFYI(1, "filldir rc = %d", rc);
 765                 rc = -EOVERFLOW;
 766         }
 767         dput(tmp_dentry);
 768         return rc;
 769 }
 770
 771
 772 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 773 {
 774         int rc = 0;
 775         int xid, i;
 776         struct cifs_sb_info *cifs_sb;
 777         struct cifsTconInfo *pTcon;
 778         struct cifsFileInfo *cifsFile = NULL;
 779         char *current_entry;
 780         int num_to_fill = 0;
 781         char *tmp_buf = NULL;
 782         char *end_of_smb;
 783         unsigned int max_len;
 784
 785         xid = GetXid();
 786
 787         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 788
 789         switch ((int) file->f_pos) {
 790         case 0:
 791                 if (filldir(direntry, ".", 1, file->f_pos,
 792                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 793                         cERROR(1, "Filldir for current dir failed");
 794                         rc = -ENOMEM;
 795                         break;
 796                 }
 797                 file->f_pos++;
 798         case 1:
 799                 if (filldir(direntry, "..", 2, file->f_pos,
 800                      file->f_path.dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
 801                         cERROR(1, "Filldir for parent dir failed");
 802                         rc = -ENOMEM;
 803                         break;
 804                 }
 805                 file->f_pos++;
 806         default:
 807                 /* 1) If search is active,
 808                         is in current search buffer?
 809                         if it before then restart search
 810                         if after then keep searching till find it */
 811
 812                 if (file->private_data == NULL) {
 813                         rc = initiate_cifs_search(xid, file);
 814                         cFYI(1, "initiate cifs search rc %d", rc);
 815                         if (rc) {
 816                                 FreeXid(xid);
 817                                 return rc;
 818                         }
 819                 }
 820                 if (file->private_data == NULL) {
 821                         rc = -EINVAL;
 822                         FreeXid(xid);
 823                         return rc;
 824                 }
 825                 cifsFile = file->private_data;
 826                 if (cifsFile->srch_inf.endOfSearch) {
 827                         if (cifsFile->srch_inf.emptyDir) {
 828                                 cFYI(1, "End of search, empty dir");
 829                                 rc = 0;
 830                                 break;
 831                         }
 832                 } /* else {
 833                         cifsFile->invalidHandle = true;
 834                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 835                 } */
 836
 837                 pTcon = cifsFile->tcon;
 838                 rc = find_cifs_entry(xid, pTcon, file,
 839                                 &current_entry, &num_to_fill);
 840                 if (rc) {
 841                         cFYI(1, "fce error %d", rc);
 842                         goto rddir2_exit;
 843                 } else if (current_entry != NULL) {
 844                         cFYI(1, "entry %lld found", file->f_pos);
 845                 } else {
 846                         cFYI(1, "could not find entry");
 847                         goto rddir2_exit;
 848                 }
 849                 cFYI(1, "loop through %d times filling dir for net buf %p",
 850                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 851                 max_len = smbCalcSize((struct smb_hdr *)
 852                                 cifsFile->srch_inf.ntwrk_buf_start);
 853                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 854
 855                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 856                 if (tmp_buf == NULL) {
 857                         rc = -ENOMEM;
 858                         break;
 859                 }
 860
 861                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 862                         if (current_entry == NULL) {
 863                                 /* evaluate whether this case is an error */
 864                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 865                                           num_to_fill, i);
 866                                 break;
 867                         }
 868                         /* if buggy server returns . and .. late do
 869                         we want to check for that here? */
 870                         rc = cifs_filldir(current_entry, file,
 871                                         filldir, direntry, tmp_buf, max_len);
 872                         if (rc == -EOVERFLOW) {
 873                                 rc = 0;
 874                                 break;
 875                         }
 876
 877                         file->f_pos++;
 878                         if (file->f_pos ==
 879                                 cifsFile->srch_inf.index_of_last_entry) {
 880                                 cFYI(1, "last entry in buf at pos %lld %s",
 881                                         file->f_pos, tmp_buf);
 882                                 cifs_save_resume_key(current_entry, cifsFile);
 883                                 break;
 884                         } else
 885                                 current_entry =
 886                                         nxt_dir_entry(current_entry, end_of_smb,
 887                                                 cifsFile->srch_inf.info_level);
 888                 }
 889                 kfree(tmp_buf);
 890                 break;
 891         } /* end switch */
 892
 893 rddir2_exit:
 894         FreeXid(xid);
 895         return rc;
 896 }