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  *   Copyright (C) Red Hat, Inc., 2011
   8  *   Author(s): Steve French (sfrench@us.ibm.com)
   9  *
  10  *   This library is free software; you can redistribute it and/or modify
  11  *   it under the terms of the GNU Lesser General Public License as published
  12  *   by the Free Software Foundation; either version 2.1 of the License, or
  13  *   (at your option) any later version.
  14  *
  15  *   This library is distributed in the hope that it will be useful,
  16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  18  *   the GNU Lesser General Public License for more details.
  19  *
  20  *   You should have received a copy of the GNU Lesser General Public License
  21  *   along with this library; if not, write to the Free Software
  22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24 #include <linux/fs.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/slab.h>
  27 #include <linux/stat.h>
  28 #include "cifspdu.h"
  29 #include "cifsglob.h"
  30 #include "cifsproto.h"
  31 #include "cifs_unicode.h"
  32 #include "cifs_debug.h"
  33 #include "cifs_fs_sb.h"
  34 #include "cifsfs.h"
  35
  36 /*
  37  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  38  * characters alloc more to account for such multibyte target UTF-8
  39  * characters.
  40  */
  41 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  42
  43 #ifdef CONFIG_CIFS_DEBUG2
  44 static void dump_cifs_file_struct(struct file *file, char *label)
  45 {
  46         struct cifsFileInfo *cf;
  47
  48         if (file) {
  49                 cf = file->private_data;
  50                 if (cf == NULL) {
  51                         cFYI(1, "empty cifs private file data");
  52                         return;
  53                 }
  54                 if (cf->invalidHandle)
  55                         cFYI(1, "invalid handle");
  56                 if (cf->srch_inf.endOfSearch)
  57                         cFYI(1, "end of search");
  58                 if (cf->srch_inf.emptyDir)
  59                         cFYI(1, "empty dir");
  60         }
  61 }
  62 #else
  63 static inline void dump_cifs_file_struct(struct file *file, char *label)
  64 {
  65 }
  66 #endif /* DEBUG2 */
  67
  68 /*
  69  * Find the dentry that matches "name". If there isn't one, create one. If it's
  70  * a negative dentry or the uniqueid changed, then drop it and recreate it.
  71  */
  72 static struct dentry *
  73 cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
  74                     struct cifs_fattr *fattr)
  75 {
  76         struct dentry *dentry, *alias;
  77         struct inode *inode;
  78         struct super_block *sb = parent->d_inode->i_sb;
  79
  80         cFYI(1, "For %s", name->name);
  81
  82         if (parent->d_op && parent->d_op->d_hash)
  83                 parent->d_op->d_hash(parent, parent->d_inode, name);
  84         else
  85                 name->hash = full_name_hash(name->name, name->len);
  86
  87         dentry = d_lookup(parent, name);
  88         if (dentry) {
  89                 inode = dentry->d_inode;
  90                 /* update inode in place if i_ino didn't change */
  91                 if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
  92                         cifs_fattr_to_inode(inode, fattr);
  93                         return dentry;
  94                 }
  95                 d_drop(dentry);
  96                 dput(dentry);
  97         }
  98
  99         /*
 100          * If we know that the inode will need to be revalidated immediately,
 101          * then don't create a new dentry for it. We'll end up doing an on
 102          * the wire call either way and this spares us an invalidation.
 103          */
 104         if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
 105                 return NULL;
 106
 107         dentry = d_alloc(parent, name);
 108         if (dentry == NULL)
 109                 return NULL;
 110
 111         inode = cifs_iget(sb, fattr);
 112         if (!inode) {
 113                 dput(dentry);
 114                 return NULL;
 115         }
 116
 117         alias = d_materialise_unique(dentry, inode);
 118         if (alias != NULL) {
 119                 dput(dentry);
 120                 if (IS_ERR(alias))
 121                         return NULL;
 122                 dentry = alias;
 123         }
 124
 125         return dentry;
 126 }
 127
 128 static void
 129 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 130 {
 131         fattr->cf_uid = cifs_sb->mnt_uid;
 132         fattr->cf_gid = cifs_sb->mnt_gid;
 133
 134         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 135                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 136                 fattr->cf_dtype = DT_DIR;
 137         } else {
 138                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 139                 fattr->cf_dtype = DT_REG;
 140         }
 141
 142         if (fattr->cf_cifsattrs & ATTR_READONLY)
 143                 fattr->cf_mode &= ~S_IWUGO;
 144
 145         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 146             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 147                 if (fattr->cf_eof == 0)  {
 148                         fattr->cf_mode &= ~S_IFMT;
 149                         fattr->cf_mode |= S_IFIFO;
 150                         fattr->cf_dtype = DT_FIFO;
 151                 } else {
 152                         /*
 153                          * trying to get the type and mode via SFU can be slow,
 154                          * so just call those regular files for now, and mark
 155                          * for reval
 156                          */
 157                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 158                 }
 159         }
 160 }
 161
 162 static void
 163 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 164                        struct cifs_sb_info *cifs_sb)
 165 {
 166         memset(fattr, 0, sizeof(*fattr));
 167         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 168         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 169         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 170         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 171         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 172         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 173         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 174
 175         cifs_fill_common_info(fattr, cifs_sb);
 176 }
 177
 178 static void
 179 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 180                        struct cifs_sb_info *cifs_sb)
 181 {
 182         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 183
 184         memset(fattr, 0, sizeof(*fattr));
 185         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 186                                             info->LastAccessTime, offset);
 187         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 188                                             info->LastWriteTime, offset);
 189         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 190                                             info->LastWriteTime, offset);
 191
 192         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 193         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 194         fattr->cf_eof = le32_to_cpu(info->DataSize);
 195
 196         cifs_fill_common_info(fattr, cifs_sb);
 197 }
 198
 199 /* BB eventually need to add the following helper function to
 200       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 201       we try to do FindFirst on (NTFS) directory symlinks */
 202 /*
 203 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 204                              int xid)
 205 {
 206         __u16 fid;
 207         int len;
 208         int oplock = 0;
 209         int rc;
 210         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 211         char *tmpbuffer;
 212
 213         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 214                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 215                         cifs_sb->local_nls,
 216                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 217         if (!rc) {
 218                 tmpbuffer = kmalloc(maxpath);
 219                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 220                                 tmpbuffer,
 221                                 maxpath -1,
 222                                 fid,
 223                                 cifs_sb->local_nls);
 224                 if (CIFSSMBClose(xid, ptcon, fid)) {
 225                         cFYI(1, "Error closing temporary reparsepoint open");
 226                 }
 227         }
 228 }
 229  */
 230
 231 static int initiate_cifs_search(const int xid, struct file *file)
 232 {
 233         __u16 search_flags;
 234         int rc = 0;
 235         char *full_path = NULL;
 236         struct cifsFileInfo *cifsFile;
 237         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 238         struct tcon_link *tlink = NULL;
 239         struct cifs_tcon *pTcon;
 240
 241         if (file->private_data == NULL) {
 242                 tlink = cifs_sb_tlink(cifs_sb);
 243                 if (IS_ERR(tlink))
 244                         return PTR_ERR(tlink);
 245
 246                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 247                 if (cifsFile == NULL) {
 248                         rc = -ENOMEM;
 249                         goto error_exit;
 250                 }
 251                 file->private_data = cifsFile;
 252                 cifsFile->tlink = cifs_get_tlink(tlink);
 253                 pTcon = tlink_tcon(tlink);
 254         } else {
 255                 cifsFile = file->private_data;
 256                 pTcon = tlink_tcon(cifsFile->tlink);
 257         }
 258
 259         cifsFile->invalidHandle = true;
 260         cifsFile->srch_inf.endOfSearch = false;
 261
 262         full_path = build_path_from_dentry(file->f_path.dentry);
 263         if (full_path == NULL) {
 264                 rc = -ENOMEM;
 265                 goto error_exit;
 266         }
 267
 268         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 269
 270 ffirst_retry:
 271         /* test for Unix extensions */
 272         /* but now check for them on the share/mount not on the SMB session */
 273 /*      if (pTcon->ses->capabilities & CAP_UNIX) { */
 274         if (pTcon->unix_ext)
 275                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 276         else if ((pTcon->ses->capabilities &
 277                         (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
 278                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 279         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 280                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 281         } else /* not srvinos - BB fixme add check for backlevel? */ {
 282                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 283         }
 284
 285         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 286         if (backup_cred(cifs_sb))
 287                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 288
 289         rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
 290                 &cifsFile->netfid, search_flags, &cifsFile->srch_inf,
 291                 cifs_sb->mnt_cifs_flags &
 292                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
 293         if (rc == 0)
 294                 cifsFile->invalidHandle = false;
 295         /* BB add following call to handle readdir on new NTFS symlink errors
 296         else if STATUS_STOPPED_ON_SYMLINK
 297                 call get_symlink_reparse_path and retry with new path */
 298         else if ((rc == -EOPNOTSUPP) &&
 299                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 300                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 301                 goto ffirst_retry;
 302         }
 303 error_exit:
 304         kfree(full_path);
 305         cifs_put_tlink(tlink);
 306         return rc;
 307 }
 308
 309 /* return length of unicode string in bytes */
 310 static int cifs_unicode_bytelen(const char *str)
 311 {
 312         int len;
 313         const __le16 *ustr = (const __le16 *)str;
 314
 315         for (len = 0; len <= PATH_MAX; len++) {
 316                 if (ustr[len] == 0)
 317                         return len << 1;
 318         }
 319         cFYI(1, "Unicode string longer than PATH_MAX found");
 320         return len << 1;
 321 }
 322
 323 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 324 {
 325         char *new_entry;
 326         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 327
 328         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 329                 FIND_FILE_STANDARD_INFO *pfData;
 330                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 331
 332                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 333                                 pfData->FileNameLength;
 334         } else
 335                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 336         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 337         /* validate that new_entry is not past end of SMB */
 338         if (new_entry >= end_of_smb) {
 339                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 340                         new_entry, end_of_smb, old_entry);
 341                 return NULL;
 342         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 343                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 344                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 345                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 346                 cERROR(1, "search entry %p extends after end of SMB %p",
 347                         new_entry, end_of_smb);
 348                 return NULL;
 349         } else
 350                 return new_entry;
 351
 352 }
 353
 354 struct cifs_dirent {
 355         const char      *name;
 356         size_t          namelen;
 357         u32             resume_key;
 358         u64             ino;
 359 };
 360
 361 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 362                 const FILE_UNIX_INFO *info, bool is_unicode)
 363 {
 364         de->name = &info->FileName[0];
 365         if (is_unicode)
 366                 de->namelen = cifs_unicode_bytelen(de->name);
 367         else
 368                 de->namelen = strnlen(de->name, PATH_MAX);
 369         de->resume_key = info->ResumeKey;
 370         de->ino = le64_to_cpu(info->basic.UniqueId);
 371 }
 372
 373 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 374                 const FILE_DIRECTORY_INFO *info)
 375 {
 376         de->name = &info->FileName[0];
 377         de->namelen = le32_to_cpu(info->FileNameLength);
 378         de->resume_key = info->FileIndex;
 379 }
 380
 381 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 382                 const FILE_FULL_DIRECTORY_INFO *info)
 383 {
 384         de->name = &info->FileName[0];
 385         de->namelen = le32_to_cpu(info->FileNameLength);
 386         de->resume_key = info->FileIndex;
 387 }
 388
 389 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 390                 const SEARCH_ID_FULL_DIR_INFO *info)
 391 {
 392         de->name = &info->FileName[0];
 393         de->namelen = le32_to_cpu(info->FileNameLength);
 394         de->resume_key = info->FileIndex;
 395         de->ino = le64_to_cpu(info->UniqueId);
 396 }
 397
 398 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 399                 const FILE_BOTH_DIRECTORY_INFO *info)
 400 {
 401         de->name = &info->FileName[0];
 402         de->namelen = le32_to_cpu(info->FileNameLength);
 403         de->resume_key = info->FileIndex;
 404 }
 405
 406 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 407                 const FIND_FILE_STANDARD_INFO *info)
 408 {
 409         de->name = &info->FileName[0];
 410         /* one byte length, no endianess conversion */
 411         de->namelen = info->FileNameLength;
 412         de->resume_key = info->ResumeKey;
 413 }
 414
 415 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 416                 u16 level, bool is_unicode)
 417 {
 418         memset(de, 0, sizeof(*de));
 419
 420         switch (level) {
 421         case SMB_FIND_FILE_UNIX:
 422                 cifs_fill_dirent_unix(de, info, is_unicode);
 423                 break;
 424         case SMB_FIND_FILE_DIRECTORY_INFO:
 425                 cifs_fill_dirent_dir(de, info);
 426                 break;
 427         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 428                 cifs_fill_dirent_full(de, info);
 429                 break;
 430         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 431                 cifs_fill_dirent_search(de, info);
 432                 break;
 433         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 434                 cifs_fill_dirent_both(de, info);
 435                 break;
 436         case SMB_FIND_FILE_INFO_STANDARD:
 437                 cifs_fill_dirent_std(de, info);
 438                 break;
 439         default:
 440                 cFYI(1, "Unknown findfirst level %d", level);
 441                 return -EINVAL;
 442         }
 443
 444         return 0;
 445 }
 446
 447 #define UNICODE_DOT cpu_to_le16(0x2e)
 448
 449 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 450 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 451 {
 452         int rc = 0;
 453
 454         if (!de->name)
 455                 return 0;
 456
 457         if (is_unicode) {
 458                 __le16 *ufilename = (__le16 *)de->name;
 459                 if (de->namelen == 2) {
 460                         /* check for . */
 461                         if (ufilename[0] == UNICODE_DOT)
 462                                 rc = 1;
 463                 } else if (de->namelen == 4) {
 464                         /* check for .. */
 465                         if (ufilename[0] == UNICODE_DOT &&
 466                             ufilename[1] == UNICODE_DOT)
 467                                 rc = 2;
 468                 }
 469         } else /* ASCII */ {
 470                 if (de->namelen == 1) {
 471                         if (de->name[0] == '.')
 472                                 rc = 1;
 473                 } else if (de->namelen == 2) {
 474                         if (de->name[0] == '.' && de->name[1] == '.')
 475                                 rc = 2;
 476                 }
 477         }
 478
 479         return rc;
 480 }
 481
 482 /* Check if directory that we are searching has changed so we can decide
 483    whether we can use the cached search results from the previous search */
 484 static int is_dir_changed(struct file *file)
 485 {
 486         struct inode *inode = file->f_path.dentry->d_inode;
 487         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 488
 489         if (cifsInfo->time == 0)
 490                 return 1; /* directory was changed, perhaps due to unlink */
 491         else
 492                 return 0;
 493
 494 }
 495
 496 static int cifs_save_resume_key(const char *current_entry,
 497         struct cifsFileInfo *file_info)
 498 {
 499         struct cifs_dirent de;
 500         int rc;
 501
 502         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 503                               file_info->srch_inf.unicode);
 504         if (!rc) {
 505                 file_info->srch_inf.presume_name = de.name;
 506                 file_info->srch_inf.resume_name_len = de.namelen;
 507                 file_info->srch_inf.resume_key = de.resume_key;
 508         }
 509         return rc;
 510 }
 511
 512 /* find the corresponding entry in the search */
 513 /* Note that the SMB server returns search entries for . and .. which
 514    complicates logic here if we choose to parse for them and we do not
 515    assume that they are located in the findfirst return buffer.*/
 516 /* We start counting in the buffer with entry 2 and increment for every
 517    entry (do not increment for . or .. entry) */
 518 static int find_cifs_entry(const int xid, struct cifs_tcon *pTcon,
 519         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 520 {
 521         __u16 search_flags;
 522         int rc = 0;
 523         int pos_in_buf = 0;
 524         loff_t first_entry_in_buffer;
 525         loff_t index_to_find = file->f_pos;
 526         struct cifsFileInfo *cifsFile = file->private_data;
 527         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 528         /* check if index in the buffer */
 529
 530         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 531            (num_to_ret == NULL))
 532                 return -ENOENT;
 533
 534         *ppCurrentEntry = NULL;
 535         first_entry_in_buffer =
 536                 cifsFile->srch_inf.index_of_last_entry -
 537                         cifsFile->srch_inf.entries_in_buffer;
 538
 539         /* if first entry in buf is zero then is first buffer
 540         in search response data which means it is likely . and ..
 541         will be in this buffer, although some servers do not return
 542         . and .. for the root of a drive and for those we need
 543         to start two entries earlier */
 544
 545         dump_cifs_file_struct(file, "In fce ");
 546         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 547              is_dir_changed(file)) ||
 548            (index_to_find < first_entry_in_buffer)) {
 549                 /* close and restart search */
 550                 cFYI(1, "search backing up - close and restart search");
 551                 spin_lock(&cifs_file_list_lock);
 552                 if (!cifsFile->srch_inf.endOfSearch &&
 553                     !cifsFile->invalidHandle) {
 554                         cifsFile->invalidHandle = true;
 555                         spin_unlock(&cifs_file_list_lock);
 556                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 557                 } else
 558                         spin_unlock(&cifs_file_list_lock);
 559                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 560                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 561                         if (cifsFile->srch_inf.smallBuf)
 562                                 cifs_small_buf_release(cifsFile->srch_inf.
 563                                                 ntwrk_buf_start);
 564                         else
 565                                 cifs_buf_release(cifsFile->srch_inf.
 566                                                 ntwrk_buf_start);
 567                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 568                 }
 569                 rc = initiate_cifs_search(xid, file);
 570                 if (rc) {
 571                         cFYI(1, "error %d reinitiating a search on rewind",
 572                                  rc);
 573                         return rc;
 574                 }
 575                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 576                 if (cifsFile->srch_inf.last_entry)
 577                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 578                                                 cifsFile);
 579         }
 580
 581         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 582         if (backup_cred(cifs_sb))
 583                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 584
 585         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 586               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 587                 cFYI(1, "calling findnext2");
 588                 rc = CIFSFindNext(xid, pTcon, cifsFile->netfid, search_flags,
 589                                   &cifsFile->srch_inf);
 590                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 591                 if (cifsFile->srch_inf.last_entry)
 592                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 593                                                 cifsFile);
 594                 if (rc)
 595                         return -ENOENT;
 596         }
 597         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 598                 /* we found the buffer that contains the entry */
 599                 /* scan and find it */
 600                 int i;
 601                 char *current_entry;
 602                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 603                         smbCalcSize((struct smb_hdr *)
 604                                 cifsFile->srch_inf.ntwrk_buf_start);
 605
 606                 current_entry = cifsFile->srch_inf.srch_entries_start;
 607                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 608                                         - cifsFile->srch_inf.entries_in_buffer;
 609                 pos_in_buf = index_to_find - first_entry_in_buffer;
 610                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 611
 612                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 613                         /* go entry by entry figuring out which is first */
 614                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 615                                                 cifsFile->srch_inf.info_level);
 616                 }
 617                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 618                         /* BB fixme - check if we should flag this error */
 619                         cERROR(1, "reached end of buf searching for pos in buf"
 620                           " %d index to find %lld rc %d",
 621                           pos_in_buf, index_to_find, rc);
 622                 }
 623                 rc = 0;
 624                 *ppCurrentEntry = current_entry;
 625         } else {
 626                 cFYI(1, "index not in buffer - could not findnext into it");
 627                 return 0;
 628         }
 629
 630         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 631                 cFYI(1, "can not return entries pos_in_buf beyond last");
 632                 *num_to_ret = 0;
 633         } else
 634                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 635
 636         return rc;
 637 }
 638
 639 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 640                 void *dirent, char *scratch_buf, unsigned int max_len)
 641 {
 642         struct cifsFileInfo *file_info = file->private_data;
 643         struct super_block *sb = file->f_path.dentry->d_sb;
 644         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 645         struct cifs_dirent de = { NULL, };
 646         struct cifs_fattr fattr;
 647         struct dentry *dentry;
 648         struct qstr name;
 649         int rc = 0;
 650         ino_t ino;
 651
 652         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 653                               file_info->srch_inf.unicode);
 654         if (rc)
 655                 return rc;
 656
 657         if (de.namelen > max_len) {
 658                 cERROR(1, "bad search response length %zd past smb end",
 659                           de.namelen);
 660                 return -EINVAL;
 661         }
 662
 663         /* skip . and .. since we added them first */
 664         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 665                 return 0;
 666
 667         if (file_info->srch_inf.unicode) {
 668                 struct nls_table *nlt = cifs_sb->local_nls;
 669
 670                 name.name = scratch_buf;
 671                 name.len =
 672                         cifs_from_ucs2((char *)name.name, (__le16 *)de.name,
 673                                        UNICODE_NAME_MAX,
 674                                        min(de.namelen, (size_t)max_len), nlt,
 675                                        cifs_sb->mnt_cifs_flags &
 676                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 677                 name.len -= nls_nullsize(nlt);
 678         } else {
 679                 name.name = de.name;
 680                 name.len = de.namelen;
 681         }
 682
 683         switch (file_info->srch_inf.info_level) {
 684         case SMB_FIND_FILE_UNIX:
 685                 cifs_unix_basic_to_fattr(&fattr,
 686                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 687                                          cifs_sb);
 688                 break;
 689         case SMB_FIND_FILE_INFO_STANDARD:
 690                 cifs_std_info_to_fattr(&fattr,
 691                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 692                                        cifs_sb);
 693                 break;
 694         default:
 695                 cifs_dir_info_to_fattr(&fattr,
 696                                        (FILE_DIRECTORY_INFO *)find_entry,
 697                                        cifs_sb);
 698                 break;
 699         }
 700
 701         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 702                 fattr.cf_uniqueid = de.ino;
 703         } else {
 704                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 705                 cifs_autodisable_serverino(cifs_sb);
 706         }
 707
 708         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 709             CIFSCouldBeMFSymlink(&fattr))
 710                 /*
 711                  * trying to get the type and mode can be slow,
 712                  * so just call those regular files for now, and mark
 713                  * for reval
 714                  */
 715                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 716
 717         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 718         dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
 719
 720         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 721                      fattr.cf_dtype);
 722
 723         dput(dentry);
 724         return rc;
 725 }
 726
 727
 728 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 729 {
 730         int rc = 0;
 731         int xid, i;
 732         struct cifs_tcon *pTcon;
 733         struct cifsFileInfo *cifsFile = NULL;
 734         char *current_entry;
 735         int num_to_fill = 0;
 736         char *tmp_buf = NULL;
 737         char *end_of_smb;
 738         unsigned int max_len;
 739
 740         xid = GetXid();
 741
 742         /*
 743          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 744          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 745          */
 746         if (file->private_data == NULL) {
 747                 rc = initiate_cifs_search(xid, file);
 748                 cFYI(1, "initiate cifs search rc %d", rc);
 749                 if (rc)
 750                         goto rddir2_exit;
 751         }
 752
 753         switch ((int) file->f_pos) {
 754         case 0:
 755                 if (filldir(direntry, ".", 1, file->f_pos,
 756                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 757                         cERROR(1, "Filldir for current dir failed");
 758                         rc = -ENOMEM;
 759                         break;
 760                 }
 761                 file->f_pos++;
 762         case 1:
 763                 if (filldir(direntry, "..", 2, file->f_pos,
 764                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 765                         cERROR(1, "Filldir for parent dir failed");
 766                         rc = -ENOMEM;
 767                         break;
 768                 }
 769                 file->f_pos++;
 770         default:
 771                 /* 1) If search is active,
 772                         is in current search buffer?
 773                         if it before then restart search
 774                         if after then keep searching till find it */
 775
 776                 if (file->private_data == NULL) {
 777                         rc = -EINVAL;
 778                         FreeXid(xid);
 779                         return rc;
 780                 }
 781                 cifsFile = file->private_data;
 782                 if (cifsFile->srch_inf.endOfSearch) {
 783                         if (cifsFile->srch_inf.emptyDir) {
 784                                 cFYI(1, "End of search, empty dir");
 785                                 rc = 0;
 786                                 break;
 787                         }
 788                 } /* else {
 789                         cifsFile->invalidHandle = true;
 790                         CIFSFindClose(xid, pTcon, cifsFile->netfid);
 791                 } */
 792
 793                 pTcon = tlink_tcon(cifsFile->tlink);
 794                 rc = find_cifs_entry(xid, pTcon, file,
 795                                 &current_entry, &num_to_fill);
 796                 if (rc) {
 797                         cFYI(1, "fce error %d", rc);
 798                         goto rddir2_exit;
 799                 } else if (current_entry != NULL) {
 800                         cFYI(1, "entry %lld found", file->f_pos);
 801                 } else {
 802                         cFYI(1, "could not find entry");
 803                         goto rddir2_exit;
 804                 }
 805                 cFYI(1, "loop through %d times filling dir for net buf %p",
 806                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 807                 max_len = smbCalcSize((struct smb_hdr *)
 808                                 cifsFile->srch_inf.ntwrk_buf_start);
 809                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 810
 811                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 812                 if (tmp_buf == NULL) {
 813                         rc = -ENOMEM;
 814                         break;
 815                 }
 816
 817                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 818                         if (current_entry == NULL) {
 819                                 /* evaluate whether this case is an error */
 820                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 821                                           num_to_fill, i);
 822                                 break;
 823                         }
 824                         /* if buggy server returns . and .. late do
 825                         we want to check for that here? */
 826                         *tmp_buf = 0;
 827                         rc = cifs_filldir(current_entry, file,
 828                                         filldir, direntry, tmp_buf, max_len);
 829                         if (rc == -EOVERFLOW) {
 830                                 rc = 0;
 831                                 break;
 832                         }
 833
 834                         file->f_pos++;
 835                         if (file->f_pos ==
 836                                 cifsFile->srch_inf.index_of_last_entry) {
 837                                 cFYI(1, "last entry in buf at pos %lld %s",
 838                                         file->f_pos, tmp_buf);
 839                                 cifs_save_resume_key(current_entry, cifsFile);
 840                                 break;
 841                         } else
 842                                 current_entry =
 843                                         nxt_dir_entry(current_entry, end_of_smb,
 844                                                 cifsFile->srch_inf.info_level);
 845                 }
 846                 kfree(tmp_buf);
 847                 break;
 848         } /* end switch */
 849
 850 rddir2_exit:
 851         FreeXid(xid);
 852         return rc;
 853 }