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