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, parent->d_inode, 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         alias = d_materialise_unique(dentry, inode);
 106         if (alias != NULL) {
 107                 dput(dentry);
 108                 if (IS_ERR(alias))
 109                         return NULL;
 110                 dentry = alias;
 111         }
 112
 113         return dentry;
 114 }
 115
 116 static void
 117 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 118 {
 119         fattr->cf_uid = cifs_sb->mnt_uid;
 120         fattr->cf_gid = cifs_sb->mnt_gid;
 121
 122         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 123                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 124                 fattr->cf_dtype = DT_DIR;
 125         } else {
 126                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 127                 fattr->cf_dtype = DT_REG;
 128         }
 129
 130         if (fattr->cf_cifsattrs & ATTR_READONLY)
 131                 fattr->cf_mode &= ~S_IWUGO;
 132
 133         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 134             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 135                 if (fattr->cf_eof == 0)  {
 136                         fattr->cf_mode &= ~S_IFMT;
 137                         fattr->cf_mode |= S_IFIFO;
 138                         fattr->cf_dtype = DT_FIFO;
 139                 } else {
 140                         /*
 141                          * trying to get the type and mode via SFU can be slow,
 142                          * so just call those regular files for now, and mark
 143                          * for reval
 144                          */
 145                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 146                 }
 147         }
 148 }
 149
 150 static void
 151 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 152                        struct cifs_sb_info *cifs_sb)
 153 {
 154         memset(fattr, 0, sizeof(*fattr));
 155         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 156         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 157         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 158         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 159         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 160         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 161         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 162
 163         cifs_fill_common_info(fattr, cifs_sb);
 164 }
 165
 166 static void
 167 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 168                        struct cifs_sb_info *cifs_sb)
 169 {
 170         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 171
 172         memset(fattr, 0, sizeof(*fattr));
 173         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 174                                             info->LastAccessTime, offset);
 175         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 176                                             info->LastWriteTime, offset);
 177         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 178                                             info->LastWriteTime, offset);
 179
 180         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 181         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 182         fattr->cf_eof = le32_to_cpu(info->DataSize);
 183
 184         cifs_fill_common_info(fattr, cifs_sb);
 185 }
 186
 187 /* BB eventually need to add the following helper function to
 188       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 189       we try to do FindFirst on (NTFS) directory symlinks */
 190 /*
 191 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 192                              int xid)
 193 {
 194         __u16 fid;
 195         int len;
 196         int oplock = 0;
 197         int rc;
 198         struct cifsTconInfo *ptcon = cifs_sb_tcon(cifs_sb);
 199         char *tmpbuffer;
 200
 201         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 202                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 203                         cifs_sb->local_nls,
 204                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 205         if (!rc) {
 206                 tmpbuffer = kmalloc(maxpath);
 207                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 208                                 tmpbuffer,
 209                                 maxpath -1,
 210                                 fid,
 211                                 cifs_sb->local_nls);
 212                 if (CIFSSMBClose(xid, ptcon, fid)) {
 213                         cFYI(1, "Error closing temporary reparsepoint open");
 214                 }
 215         }
 216 }
 217  */
 218
 219 static int initiate_cifs_search(const int xid, struct file *file)
 220 {
 221         int rc = 0;
 222         char *full_path = NULL;
 223         struct cifsFileInfo *cifsFile;
 224         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 225         struct tcon_link *tlink = NULL;
 226         struct cifsTconInfo *pTcon;
 227
 228         if (file->private_data == NULL) {
 229                 tlink = cifs_sb_tlink(cifs_sb);
 230                 if (IS_ERR(tlink))
 231                         return PTR_ERR(tlink);
 232
 233                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 234                 if (cifsFile == NULL) {
 235                         rc = -ENOMEM;
 236                         goto error_exit;
 237                 }
 238                 file->private_data = cifsFile;
 239                 cifsFile->tlink = cifs_get_tlink(tlink);
 240                 pTcon = tlink_tcon(tlink);
 241         } else {
 242                 cifsFile = file->private_data;
 243                 pTcon = tlink_tcon(cifsFile->tlink);
 244         }
 245
 246         cifsFile->invalidHandle = true;
 247         cifsFile->srch_inf.endOfSearch = false;
 248
 249         full_path = build_path_from_dentry(file->f_path.dentry);
 250         if (full_path == NULL) {
 251                 rc = -ENOMEM;
 252                 goto error_exit;
 253         }
 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 error_exit:
 287         kfree(full_path);
 288         cifs_put_tlink(tlink);
 289         return rc;
 290 }
 291
 292 /* return length of unicode string in bytes */
 293 static int cifs_unicode_bytelen(char *str)
 294 {
 295         int len;
 296         __le16 *ustr = (__le16 *)str;
 297
 298         for (len = 0; len <= PATH_MAX; len++) {
 299                 if (ustr[len] == 0)
 300                         return len << 1;
 301         }
 302         cFYI(1, "Unicode string longer than PATH_MAX found");
 303         return len << 1;
 304 }
 305
 306 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 307 {
 308         char *new_entry;
 309         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 310
 311         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 312                 FIND_FILE_STANDARD_INFO *pfData;
 313                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 314
 315                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 316                                 pfData->FileNameLength;
 317         } else
 318                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 319         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 320         /* validate that new_entry is not past end of SMB */
 321         if (new_entry >= end_of_smb) {
 322                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 323                         new_entry, end_of_smb, old_entry);
 324                 return NULL;
 325         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 326                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 327                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 328                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 329                 cERROR(1, "search entry %p extends after end of SMB %p",
 330                         new_entry, end_of_smb);
 331                 return NULL;
 332         } else
 333                 return new_entry;
 334
 335 }
 336
 337 #define UNICODE_DOT cpu_to_le16(0x2e)
 338
 339 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 340 static int cifs_entry_is_dot(char *current_entry, struct cifsFileInfo *cfile)
 341 {
 342         int rc = 0;
 343         char *filename = NULL;
 344         int len = 0;
 345
 346         if (cfile->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
 347                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 348                 filename = &pFindData->FileName[0];
 349                 if (cfile->srch_inf.unicode) {
 350                         len = cifs_unicode_bytelen(filename);
 351                 } else {
 352                         /* BB should we make this strnlen of PATH_MAX? */
 353                         len = strnlen(filename, 5);
 354                 }
 355         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_DIRECTORY_INFO) {
 356                 FILE_DIRECTORY_INFO *pFindData =
 357                         (FILE_DIRECTORY_INFO *)current_entry;
 358                 filename = &pFindData->FileName[0];
 359                 len = le32_to_cpu(pFindData->FileNameLength);
 360         } else if (cfile->srch_inf.info_level ==
 361                         SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 362                 FILE_FULL_DIRECTORY_INFO *pFindData =
 363                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 364                 filename = &pFindData->FileName[0];
 365                 len = le32_to_cpu(pFindData->FileNameLength);
 366         } else if (cfile->srch_inf.info_level ==
 367                         SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 368                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 369                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 370                 filename = &pFindData->FileName[0];
 371                 len = le32_to_cpu(pFindData->FileNameLength);
 372         } else if (cfile->srch_inf.info_level ==
 373                         SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 374                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 375                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 376                 filename = &pFindData->FileName[0];
 377                 len = le32_to_cpu(pFindData->FileNameLength);
 378         } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD) {
 379                 FIND_FILE_STANDARD_INFO *pFindData =
 380                         (FIND_FILE_STANDARD_INFO *)current_entry;
 381                 filename = &pFindData->FileName[0];
 382                 len = pFindData->FileNameLength;
 383         } else {
 384                 cFYI(1, "Unknown findfirst level %d",
 385                          cfile->srch_inf.info_level);
 386         }
 387
 388         if (filename) {
 389                 if (cfile->srch_inf.unicode) {
 390                         __le16 *ufilename = (__le16 *)filename;
 391                         if (len == 2) {
 392                                 /* check for . */
 393                                 if (ufilename[0] == UNICODE_DOT)
 394                                         rc = 1;
 395                         } else if (len == 4) {
 396                                 /* check for .. */
 397                                 if ((ufilename[0] == UNICODE_DOT)
 398                                    && (ufilename[1] == UNICODE_DOT))
 399                                         rc = 2;
 400                         }
 401                 } else /* ASCII */ {
 402                         if (len == 1) {
 403                                 if (filename[0] == '.')
 404                                         rc = 1;
 405                         } else if (len == 2) {
 406                                 if ((filename[0] == '.') && (filename[1] == '.'))
 407                                         rc = 2;
 408                         }
 409                 }
 410         }
 411
 412         return rc;
 413 }
 414
 415 /* Check if directory that we are searching has changed so we can decide
 416    whether we can use the cached search results from the previous search */
 417 static int is_dir_changed(struct file *file)
 418 {
 419         struct inode *inode = file->f_path.dentry->d_inode;
 420         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 421
 422         if (cifsInfo->time == 0)
 423                 return 1; /* directory was changed, perhaps due to unlink */
 424         else
 425                 return 0;
 426
 427 }
 428
 429 static int cifs_save_resume_key(const char *current_entry,
 430         struct cifsFileInfo *cifsFile)
 431 {
 432         int rc = 0;
 433         unsigned int len = 0;
 434         __u16 level;
 435         char *filename;
 436
 437         if ((cifsFile == NULL) || (current_entry == NULL))
 438                 return -EINVAL;
 439
 440         level = cifsFile->srch_inf.info_level;
 441
 442         if (level == SMB_FIND_FILE_UNIX) {
 443                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 444
 445                 filename = &pFindData->FileName[0];
 446                 if (cifsFile->srch_inf.unicode) {
 447                         len = cifs_unicode_bytelen(filename);
 448                 } else {
 449                         /* BB should we make this strnlen of PATH_MAX? */
 450                         len = strnlen(filename, PATH_MAX);
 451                 }
 452                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 453         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 454                 FILE_DIRECTORY_INFO *pFindData =
 455                         (FILE_DIRECTORY_INFO *)current_entry;
 456                 filename = &pFindData->FileName[0];
 457                 len = le32_to_cpu(pFindData->FileNameLength);
 458                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 459         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 460                 FILE_FULL_DIRECTORY_INFO *pFindData =
 461                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 462                 filename = &pFindData->FileName[0];
 463                 len = le32_to_cpu(pFindData->FileNameLength);
 464                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 465         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 466                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 467                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 468                 filename = &pFindData->FileName[0];
 469                 len = le32_to_cpu(pFindData->FileNameLength);
 470                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 471         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 472                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 473                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 474                 filename = &pFindData->FileName[0];
 475                 len = le32_to_cpu(pFindData->FileNameLength);
 476                 cifsFile->srch_inf.resume_key = pFindData->FileIndex;
 477         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 478                 FIND_FILE_STANDARD_INFO *pFindData =
 479                         (FIND_FILE_STANDARD_INFO *)current_entry;
 480                 filename = &pFindData->FileName[0];
 481                 /* one byte length, no name conversion */
 482                 len = (unsigned int)pFindData->FileNameLength;
 483                 cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
 484         } else {
 485                 cFYI(1, "Unknown findfirst level %d", level);
 486                 return -EINVAL;
 487         }
 488         cifsFile->srch_inf.resume_name_len = len;
 489         cifsFile->srch_inf.presume_name = filename;
 490         return rc;
 491 }
 492
 493 /* find the corresponding entry in the search */
 494 /* Note that the SMB server returns search entries for . and .. which
 495    complicates logic here if we choose to parse for them and we do not
 496    assume that they are located in the findfirst return buffer.*/
 497 /* We start counting in the buffer with entry 2 and increment for every
 498    entry (do not increment for . or .. entry) */
 499 static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
 500         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 501 {
 502         int rc = 0;
 503         int pos_in_buf = 0;
 504         loff_t first_entry_in_buffer;
 505         loff_t index_to_find = file->f_pos;
 506         struct cifsFileInfo *cifsFile = file->private_data;
 507         /* check if index in the buffer */
 508
 509         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 510            (num_to_ret == NULL))
 511                 return -ENOENT;
 512
 513         *ppCurrentEntry = NULL;
 514         first_entry_in_buffer =
 515                 cifsFile->srch_inf.index_of_last_entry -
 516                         cifsFile->srch_inf.entries_in_buffer;
 517
 518         /* if first entry in buf is zero then is first buffer
 519         in search response data which means it is likely . and ..
 520         will be in this buffer, although some servers do not return
 521         . and .. for the root of a drive and for those we need
 522         to start two entries earlier */
 523
 524         dump_cifs_file_struct(file, "In fce ");
 525         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 526              is_dir_changed(file)) ||
 527            (index_to_find < first_entry_in_buffer)) {
 528                 /* close and restart search */
 529                 cFYI(1, "search backing up - close and restart search");
 530                 spin_lock(&cifs_file_list_lock);
 531                 if (!cifsFile->srch_inf.endOfSearch &&
 532                     !cifsFile->invalidHandle) {
 533                         cifsFile->invalidHandle = true;
 534                         spin_unlock(&cifs_file_list_lock);
 535                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 536                 } else
 537                         spin_unlock(&cifs_file_list_lock);
 538                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 539                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 540                         if (cifsFile->srch_inf.smallBuf)
 541                                 cifs_small_buf_release(cifsFile->srch_inf.
 542                                                 ntwrk_buf_start);
 543                         else
 544                                 cifs_buf_release(cifsFile->srch_inf.
 545                                                 ntwrk_buf_start);
 546                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 547                 }
 548                 rc = initiate_cifs_search(xid, file);
 549                 if (rc) {
 550                         cFYI(1, "error %d reinitiating a search on rewind",
 551                                  rc);
 552                         return rc;
 553                 }
 554                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 555         }
 556
 557         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 558               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 559                 cFYI(1, "calling findnext2");
 560                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
 561                                   &cifsFile->srch_inf);
 562                 cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
 563                 if (rc)
 564                         return -ENOENT;
 565         }
 566         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 567                 /* we found the buffer that contains the entry */
 568                 /* scan and find it */
 569                 int i;
 570                 char *current_entry;
 571                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 572                         smbCalcSize((struct smb_hdr *)
 573                                 cifsFile->srch_inf.ntwrk_buf_start);
 574
 575                 current_entry = cifsFile->srch_inf.srch_entries_start;
 576                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 577                                         - cifsFile->srch_inf.entries_in_buffer;
 578                 pos_in_buf = index_to_find - first_entry_in_buffer;
 579                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 580
 581                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 582                         /* go entry by entry figuring out which is first */
 583                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 584                                                 cifsFile->srch_inf.info_level);
 585                 }
 586                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 587                         /* BB fixme - check if we should flag this error */
 588                         cERROR(1, "reached end of buf searching for pos in buf"
 589                           " %d index to find %lld rc %d",
 590                           pos_in_buf, index_to_find, rc);
 591                 }
 592                 rc = 0;
 593                 *ppCurrentEntry = current_entry;
 594         } else {
 595                 cFYI(1, "index not in buffer - could not findnext into it");
 596                 return 0;
 597         }
 598
 599         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 600                 cFYI(1, "can not return entries pos_in_buf beyond last");
 601                 *num_to_ret = 0;
 602         } else
 603                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 604
 605         return rc;
 606 }
 607
 608 /* inode num, inode type and filename returned */
 609 static int cifs_get_name_from_search_buf(struct qstr *pqst,
 610         char *current_entry, __u16 level, unsigned int unicode,
 611         struct cifs_sb_info *cifs_sb, unsigned int max_len, __u64 *pinum)
 612 {
 613         int rc = 0;
 614         unsigned int len = 0;
 615         char *filename;
 616         struct nls_table *nlt = cifs_sb->local_nls;
 617
 618         *pinum = 0;
 619
 620         if (level == SMB_FIND_FILE_UNIX) {
 621                 FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
 622
 623                 filename = &pFindData->FileName[0];
 624                 if (unicode) {
 625                         len = cifs_unicode_bytelen(filename);
 626                 } else {
 627                         /* BB should we make this strnlen of PATH_MAX? */
 628                         len = strnlen(filename, PATH_MAX);
 629                 }
 630
 631                 *pinum = le64_to_cpu(pFindData->basic.UniqueId);
 632         } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 633                 FILE_DIRECTORY_INFO *pFindData =
 634                         (FILE_DIRECTORY_INFO *)current_entry;
 635                 filename = &pFindData->FileName[0];
 636                 len = le32_to_cpu(pFindData->FileNameLength);
 637         } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
 638                 FILE_FULL_DIRECTORY_INFO *pFindData =
 639                         (FILE_FULL_DIRECTORY_INFO *)current_entry;
 640                 filename = &pFindData->FileName[0];
 641                 len = le32_to_cpu(pFindData->FileNameLength);
 642         } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
 643                 SEARCH_ID_FULL_DIR_INFO *pFindData =
 644                         (SEARCH_ID_FULL_DIR_INFO *)current_entry;
 645                 filename = &pFindData->FileName[0];
 646                 len = le32_to_cpu(pFindData->FileNameLength);
 647                 *pinum = le64_to_cpu(pFindData->UniqueId);
 648         } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
 649                 FILE_BOTH_DIRECTORY_INFO *pFindData =
 650                         (FILE_BOTH_DIRECTORY_INFO *)current_entry;
 651                 filename = &pFindData->FileName[0];
 652                 len = le32_to_cpu(pFindData->FileNameLength);
 653         } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
 654                 FIND_FILE_STANDARD_INFO *pFindData =
 655                         (FIND_FILE_STANDARD_INFO *)current_entry;
 656                 filename = &pFindData->FileName[0];
 657                 /* one byte length, no name conversion */
 658                 len = (unsigned int)pFindData->FileNameLength;
 659         } else {
 660                 cFYI(1, "Unknown findfirst level %d", level);
 661                 return -EINVAL;
 662         }
 663
 664         if (len > max_len) {
 665                 cERROR(1, "bad search response length %d past smb end", len);
 666                 return -EINVAL;
 667         }
 668
 669         if (unicode) {
 670                 pqst->len = cifs_from_ucs2((char *) pqst->name,
 671                                            (__le16 *) filename,
 672                                            UNICODE_NAME_MAX,
 673                                            min(len, max_len), nlt,
 674                                            cifs_sb->mnt_cifs_flags &
 675                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 676                 pqst->len -= nls_nullsize(nlt);
 677         } else {
 678                 pqst->name = filename;
 679                 pqst->len = len;
 680         }
 681         return rc;
 682 }
 683
 684 static int cifs_filldir(char *pfindEntry, struct file *file, filldir_t filldir,
 685                         void *direntry, char *scratch_buf, unsigned int max_len)
 686 {
 687         int rc = 0;
 688         struct qstr qstring;
 689         struct cifsFileInfo *pCifsF;
 690         u64    inum;
 691         ino_t  ino;
 692         struct super_block *sb;
 693         struct cifs_sb_info *cifs_sb;
 694         struct dentry *tmp_dentry;
 695         struct cifs_fattr fattr;
 696
 697         /* get filename and len into qstring */
 698         /* get dentry */
 699         /* decide whether to create and populate ionde */
 700         if ((direntry == NULL) || (file == NULL))
 701                 return -EINVAL;
 702
 703         pCifsF = file->private_data;
 704
 705         if ((scratch_buf == NULL) || (pfindEntry == NULL) || (pCifsF == NULL))
 706                 return -ENOENT;
 707
 708         rc = cifs_entry_is_dot(pfindEntry, pCifsF);
 709         /* skip . and .. since we added them first */
 710         if (rc != 0)
 711                 return 0;
 712
 713         sb = file->f_path.dentry->d_sb;
 714         cifs_sb = CIFS_SB(sb);
 715
 716         qstring.name = scratch_buf;
 717         rc = cifs_get_name_from_search_buf(&qstring, pfindEntry,
 718                         pCifsF->srch_inf.info_level,
 719                         pCifsF->srch_inf.unicode, cifs_sb,
 720                         max_len, &inum /* returned */);
 721
 722         if (rc)
 723                 return rc;
 724
 725         if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX)
 726                 cifs_unix_basic_to_fattr(&fattr,
 727                                  &((FILE_UNIX_INFO *) pfindEntry)->basic,
 728                                  cifs_sb);
 729         else if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD)
 730                 cifs_std_info_to_fattr(&fattr, (FIND_FILE_STANDARD_INFO *)
 731                                         pfindEntry, cifs_sb);
 732         else
 733                 cifs_dir_info_to_fattr(&fattr, (FILE_DIRECTORY_INFO *)
 734                                         pfindEntry, cifs_sb);
 735
 736         if (inum && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 737                 fattr.cf_uniqueid = inum;
 738         } else {
 739                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 740                 cifs_autodisable_serverino(cifs_sb);
 741         }
 742
 743         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 744             CIFSCouldBeMFSymlink(&fattr))
 745                 /*
 746                  * trying to get the type and mode can be slow,
 747                  * so just call those regular files for now, and mark
 748                  * for reval
 749                  */
 750                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 751
 752         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 753         tmp_dentry = cifs_readdir_lookup(file->f_dentry, &qstring, &fattr);
 754
 755         rc = filldir(direntry, qstring.name, qstring.len, file->f_pos,
 756                      ino, fattr.cf_dtype);
 757
 758         dput(tmp_dentry);
 759         return rc;
 760 }
 761
 762
 763 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 764 {
 765         int rc = 0;
 766         int xid, i;
 767         struct cifs_sb_info *cifs_sb;
 768         struct cifsTconInfo *pTcon;
 769         struct cifsFileInfo *cifsFile = NULL;
 770         char *current_entry;
 771         int num_to_fill = 0;
 772         char *tmp_buf = NULL;
 773         char *end_of_smb;
 774         unsigned int max_len;
 775
 776         xid = GetXid();
 777
 778         cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 779
 780         /*
 781          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 782          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 783          */
 784         if (file->private_data == NULL) {
 785                 rc = initiate_cifs_search(xid, file);
 786                 cFYI(1, "initiate cifs search rc %d", rc);
 787                 if (rc)
 788                         goto rddir2_exit;
 789         }
 790
 791         switch ((int) file->f_pos) {
 792         case 0:
 793                 if (filldir(direntry, ".", 1, file->f_pos,
 794                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 795                         cERROR(1, "Filldir for current dir failed");
 796                         rc = -ENOMEM;
 797                         break;
 798                 }
 799                 file->f_pos++;
 800         case 1:
 801                 if (filldir(direntry, "..", 2, file->f_pos,
 802                      file->f_path.dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
 803                         cERROR(1, "Filldir for parent dir failed");
 804                         rc = -ENOMEM;
 805                         break;
 806                 }
 807                 file->f_pos++;
 808         default:
 809                 /* 1) If search is active,
 810                         is in current search buffer?
 811                         if it before then restart search
 812                         if after then keep searching till find it */
 813
 814                 if (file->private_data == NULL) {
 815                         rc = -EINVAL;
 816                         FreeXid(xid);
 817                         return rc;
 818                 }
 819                 cifsFile = file->private_data;
 820                 if (cifsFile->srch_inf.endOfSearch) {
 821                         if (cifsFile->srch_inf.emptyDir) {
 822                                 cFYI(1, "End of search, empty dir");
 823                                 rc = 0;
 824                                 break;
 825                         }
 826                 } /* else {
 827                         cifsFile->invalidHandle = true;
 828                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 829                 } */
 830
 831                 pTcon = tlink_tcon(cifsFile->tlink);
 832                 rc = find_cifs_entry(xid, pTcon, file,
 833                                 &current_entry, &num_to_fill);
 834                 if (rc) {
 835                         cFYI(1, "fce error %d", rc);
 836                         goto rddir2_exit;
 837                 } else if (current_entry != NULL) {
 838                         cFYI(1, "entry %lld found", file->f_pos);
 839                 } else {
 840                         cFYI(1, "could not find entry");
 841                         goto rddir2_exit;
 842                 }
 843                 cFYI(1, "loop through %d times filling dir for net buf %p",
 844                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 845                 max_len = smbCalcSize((struct smb_hdr *)
 846                                 cifsFile->srch_inf.ntwrk_buf_start);
 847                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 848
 849                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 850                 if (tmp_buf == NULL) {
 851                         rc = -ENOMEM;
 852                         break;
 853                 }
 854
 855                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 856                         if (current_entry == NULL) {
 857                                 /* evaluate whether this case is an error */
 858                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 859                                           num_to_fill, i);
 860                                 break;
 861                         }
 862                         /* if buggy server returns . and .. late do
 863                         we want to check for that here? */
 864                         rc = cifs_filldir(current_entry, file,
 865                                         filldir, direntry, tmp_buf, max_len);
 866                         if (rc == -EOVERFLOW) {
 867                                 rc = 0;
 868                                 break;
 869                         }
 870
 871                         file->f_pos++;
 872                         if (file->f_pos ==
 873                                 cifsFile->srch_inf.index_of_last_entry) {
 874                                 cFYI(1, "last entry in buf at pos %lld %s",
 875                                         file->f_pos, tmp_buf);
 876                                 cifs_save_resume_key(current_entry, cifsFile);
 877                                 break;
 878                         } else
 879                                 current_entry =
 880                                         nxt_dir_entry(current_entry, end_of_smb,
 881                                                 cifsFile->srch_inf.info_level);
 882                 }
 883                 kfree(tmp_buf);
 884                 break;
 885         } /* end switch */
 886
 887 rddir2_exit:
 888         FreeXid(xid);
 889         return rc;
 890 }