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                 int err;
  90                 inode = dentry->d_inode;
  91                 /* update inode in place if i_ino didn't change */
  92                 if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
  93                         cifs_fattr_to_inode(inode, fattr);
  94                         return dentry;
  95                 }
  96                 err = d_invalidate(dentry);
  97                 dput(dentry);
  98                 if (err)
  99                         return NULL;
 100         }
 101
 102         dentry = d_alloc(parent, name);
 103         if (dentry == NULL)
 104                 return NULL;
 105
 106         inode = cifs_iget(sb, fattr);
 107         if (!inode) {
 108                 dput(dentry);
 109                 return NULL;
 110         }
 111
 112         alias = d_materialise_unique(dentry, inode);
 113         if (alias != NULL) {
 114                 dput(dentry);
 115                 if (IS_ERR(alias))
 116                         return NULL;
 117                 dentry = alias;
 118         }
 119
 120         return dentry;
 121 }
 122
 123 static void
 124 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 125 {
 126         fattr->cf_uid = cifs_sb->mnt_uid;
 127         fattr->cf_gid = cifs_sb->mnt_gid;
 128
 129         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 130                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 131                 fattr->cf_dtype = DT_DIR;
 132         } else {
 133                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 134                 fattr->cf_dtype = DT_REG;
 135         }
 136
 137         if (fattr->cf_cifsattrs & ATTR_READONLY)
 138                 fattr->cf_mode &= ~S_IWUGO;
 139
 140         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 141             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 142                 if (fattr->cf_eof == 0)  {
 143                         fattr->cf_mode &= ~S_IFMT;
 144                         fattr->cf_mode |= S_IFIFO;
 145                         fattr->cf_dtype = DT_FIFO;
 146                 } else {
 147                         /*
 148                          * trying to get the type and mode via SFU can be slow,
 149                          * so just call those regular files for now, and mark
 150                          * for reval
 151                          */
 152                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 153                 }
 154         }
 155 }
 156
 157 void
 158 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 159                        struct cifs_sb_info *cifs_sb)
 160 {
 161         memset(fattr, 0, sizeof(*fattr));
 162         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 163         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 164         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 165         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 166         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 167         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 168         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 169
 170         cifs_fill_common_info(fattr, cifs_sb);
 171 }
 172
 173 static void
 174 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 175                        struct cifs_sb_info *cifs_sb)
 176 {
 177         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 178
 179         memset(fattr, 0, sizeof(*fattr));
 180         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 181                                             info->LastAccessTime, offset);
 182         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 183                                             info->LastWriteTime, offset);
 184         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 185                                             info->LastWriteTime, offset);
 186
 187         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 188         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 189         fattr->cf_eof = le32_to_cpu(info->DataSize);
 190
 191         cifs_fill_common_info(fattr, cifs_sb);
 192 }
 193
 194 /* BB eventually need to add the following helper function to
 195       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 196       we try to do FindFirst on (NTFS) directory symlinks */
 197 /*
 198 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 199                              unsigned int xid)
 200 {
 201         __u16 fid;
 202         int len;
 203         int oplock = 0;
 204         int rc;
 205         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 206         char *tmpbuffer;
 207
 208         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 209                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 210                         cifs_sb->local_nls,
 211                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 212         if (!rc) {
 213                 tmpbuffer = kmalloc(maxpath);
 214                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 215                                 tmpbuffer,
 216                                 maxpath -1,
 217                                 fid,
 218                                 cifs_sb->local_nls);
 219                 if (CIFSSMBClose(xid, ptcon, fid)) {
 220                         cFYI(1, "Error closing temporary reparsepoint open");
 221                 }
 222         }
 223 }
 224  */
 225
 226 static int
 227 initiate_cifs_search(const unsigned int xid, struct file *file)
 228 {
 229         __u16 search_flags;
 230         int rc = 0;
 231         char *full_path = NULL;
 232         struct cifsFileInfo *cifsFile;
 233         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 234         struct tcon_link *tlink = NULL;
 235         struct cifs_tcon *tcon;
 236         struct TCP_Server_Info *server;
 237
 238         if (file->private_data == NULL) {
 239                 tlink = cifs_sb_tlink(cifs_sb);
 240                 if (IS_ERR(tlink))
 241                         return PTR_ERR(tlink);
 242
 243                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 244                 if (cifsFile == NULL) {
 245                         rc = -ENOMEM;
 246                         goto error_exit;
 247                 }
 248                 file->private_data = cifsFile;
 249                 cifsFile->tlink = cifs_get_tlink(tlink);
 250                 tcon = tlink_tcon(tlink);
 251         } else {
 252                 cifsFile = file->private_data;
 253                 tcon = tlink_tcon(cifsFile->tlink);
 254         }
 255
 256         server = tcon->ses->server;
 257
 258         if (!server->ops->query_dir_first) {
 259                 rc = -ENOSYS;
 260                 goto error_exit;
 261         }
 262
 263         cifsFile->invalidHandle = true;
 264         cifsFile->srch_inf.endOfSearch = false;
 265
 266         full_path = build_path_from_dentry(file->f_path.dentry);
 267         if (full_path == NULL) {
 268                 rc = -ENOMEM;
 269                 goto error_exit;
 270         }
 271
 272         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 273
 274 ffirst_retry:
 275         /* test for Unix extensions */
 276         /* but now check for them on the share/mount not on the SMB session */
 277         /* if (cap_unix(tcon->ses) { */
 278         if (tcon->unix_ext)
 279                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 280         else if ((tcon->ses->capabilities &
 281                   tcon->ses->server->vals->cap_nt_find) == 0) {
 282                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 283         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 284                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 285         } else /* not srvinos - BB fixme add check for backlevel? */ {
 286                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 287         }
 288
 289         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 290         if (backup_cred(cifs_sb))
 291                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 292
 293         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 294                                           &cifsFile->fid, search_flags,
 295                                           &cifsFile->srch_inf);
 296
 297         if (rc == 0)
 298                 cifsFile->invalidHandle = false;
 299         /* BB add following call to handle readdir on new NTFS symlink errors
 300         else if STATUS_STOPPED_ON_SYMLINK
 301                 call get_symlink_reparse_path and retry with new path */
 302         else if ((rc == -EOPNOTSUPP) &&
 303                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 304                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 305                 goto ffirst_retry;
 306         }
 307 error_exit:
 308         kfree(full_path);
 309         cifs_put_tlink(tlink);
 310         return rc;
 311 }
 312
 313 /* return length of unicode string in bytes */
 314 static int cifs_unicode_bytelen(const char *str)
 315 {
 316         int len;
 317         const __le16 *ustr = (const __le16 *)str;
 318
 319         for (len = 0; len <= PATH_MAX; len++) {
 320                 if (ustr[len] == 0)
 321                         return len << 1;
 322         }
 323         cFYI(1, "Unicode string longer than PATH_MAX found");
 324         return len << 1;
 325 }
 326
 327 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 328 {
 329         char *new_entry;
 330         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 331
 332         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 333                 FIND_FILE_STANDARD_INFO *pfData;
 334                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 335
 336                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 337                                 pfData->FileNameLength;
 338         } else
 339                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 340         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 341         /* validate that new_entry is not past end of SMB */
 342         if (new_entry >= end_of_smb) {
 343                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 344                         new_entry, end_of_smb, old_entry);
 345                 return NULL;
 346         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 347                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 348                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 349                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 350                 cERROR(1, "search entry %p extends after end of SMB %p",
 351                         new_entry, end_of_smb);
 352                 return NULL;
 353         } else
 354                 return new_entry;
 355
 356 }
 357
 358 struct cifs_dirent {
 359         const char      *name;
 360         size_t          namelen;
 361         u32             resume_key;
 362         u64             ino;
 363 };
 364
 365 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 366                 const FILE_UNIX_INFO *info, bool is_unicode)
 367 {
 368         de->name = &info->FileName[0];
 369         if (is_unicode)
 370                 de->namelen = cifs_unicode_bytelen(de->name);
 371         else
 372                 de->namelen = strnlen(de->name, PATH_MAX);
 373         de->resume_key = info->ResumeKey;
 374         de->ino = le64_to_cpu(info->basic.UniqueId);
 375 }
 376
 377 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 378                 const FILE_DIRECTORY_INFO *info)
 379 {
 380         de->name = &info->FileName[0];
 381         de->namelen = le32_to_cpu(info->FileNameLength);
 382         de->resume_key = info->FileIndex;
 383 }
 384
 385 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 386                 const FILE_FULL_DIRECTORY_INFO *info)
 387 {
 388         de->name = &info->FileName[0];
 389         de->namelen = le32_to_cpu(info->FileNameLength);
 390         de->resume_key = info->FileIndex;
 391 }
 392
 393 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 394                 const SEARCH_ID_FULL_DIR_INFO *info)
 395 {
 396         de->name = &info->FileName[0];
 397         de->namelen = le32_to_cpu(info->FileNameLength);
 398         de->resume_key = info->FileIndex;
 399         de->ino = le64_to_cpu(info->UniqueId);
 400 }
 401
 402 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 403                 const FILE_BOTH_DIRECTORY_INFO *info)
 404 {
 405         de->name = &info->FileName[0];
 406         de->namelen = le32_to_cpu(info->FileNameLength);
 407         de->resume_key = info->FileIndex;
 408 }
 409
 410 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 411                 const FIND_FILE_STANDARD_INFO *info)
 412 {
 413         de->name = &info->FileName[0];
 414         /* one byte length, no endianess conversion */
 415         de->namelen = info->FileNameLength;
 416         de->resume_key = info->ResumeKey;
 417 }
 418
 419 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 420                 u16 level, bool is_unicode)
 421 {
 422         memset(de, 0, sizeof(*de));
 423
 424         switch (level) {
 425         case SMB_FIND_FILE_UNIX:
 426                 cifs_fill_dirent_unix(de, info, is_unicode);
 427                 break;
 428         case SMB_FIND_FILE_DIRECTORY_INFO:
 429                 cifs_fill_dirent_dir(de, info);
 430                 break;
 431         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 432                 cifs_fill_dirent_full(de, info);
 433                 break;
 434         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 435                 cifs_fill_dirent_search(de, info);
 436                 break;
 437         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 438                 cifs_fill_dirent_both(de, info);
 439                 break;
 440         case SMB_FIND_FILE_INFO_STANDARD:
 441                 cifs_fill_dirent_std(de, info);
 442                 break;
 443         default:
 444                 cFYI(1, "Unknown findfirst level %d", level);
 445                 return -EINVAL;
 446         }
 447
 448         return 0;
 449 }
 450
 451 #define UNICODE_DOT cpu_to_le16(0x2e)
 452
 453 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 454 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 455 {
 456         int rc = 0;
 457
 458         if (!de->name)
 459                 return 0;
 460
 461         if (is_unicode) {
 462                 __le16 *ufilename = (__le16 *)de->name;
 463                 if (de->namelen == 2) {
 464                         /* check for . */
 465                         if (ufilename[0] == UNICODE_DOT)
 466                                 rc = 1;
 467                 } else if (de->namelen == 4) {
 468                         /* check for .. */
 469                         if (ufilename[0] == UNICODE_DOT &&
 470                             ufilename[1] == UNICODE_DOT)
 471                                 rc = 2;
 472                 }
 473         } else /* ASCII */ {
 474                 if (de->namelen == 1) {
 475                         if (de->name[0] == '.')
 476                                 rc = 1;
 477                 } else if (de->namelen == 2) {
 478                         if (de->name[0] == '.' && de->name[1] == '.')
 479                                 rc = 2;
 480                 }
 481         }
 482
 483         return rc;
 484 }
 485
 486 /* Check if directory that we are searching has changed so we can decide
 487    whether we can use the cached search results from the previous search */
 488 static int is_dir_changed(struct file *file)
 489 {
 490         struct inode *inode = file->f_path.dentry->d_inode;
 491         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 492
 493         if (cifsInfo->time == 0)
 494                 return 1; /* directory was changed, perhaps due to unlink */
 495         else
 496                 return 0;
 497
 498 }
 499
 500 static int cifs_save_resume_key(const char *current_entry,
 501         struct cifsFileInfo *file_info)
 502 {
 503         struct cifs_dirent de;
 504         int rc;
 505
 506         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 507                               file_info->srch_inf.unicode);
 508         if (!rc) {
 509                 file_info->srch_inf.presume_name = de.name;
 510                 file_info->srch_inf.resume_name_len = de.namelen;
 511                 file_info->srch_inf.resume_key = de.resume_key;
 512         }
 513         return rc;
 514 }
 515
 516 /*
 517  * Find the corresponding entry in the search. Note that the SMB server returns
 518  * search entries for . and .. which complicates logic here if we choose to
 519  * parse for them and we do not assume that they are located in the findfirst
 520  * return buffer. We start counting in the buffer with entry 2 and increment for
 521  * every entry (do not increment for . or .. entry).
 522  */
 523 static int
 524 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon,
 525                 struct file *file, char **current_entry, int *num_to_ret)
 526 {
 527         __u16 search_flags;
 528         int rc = 0;
 529         int pos_in_buf = 0;
 530         loff_t first_entry_in_buffer;
 531         loff_t index_to_find = file->f_pos;
 532         struct cifsFileInfo *cfile = file->private_data;
 533         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 534         struct TCP_Server_Info *server = tcon->ses->server;
 535         /* check if index in the buffer */
 536
 537         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 538                 return -ENOSYS;
 539
 540         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 541                 return -ENOENT;
 542
 543         *current_entry = NULL;
 544         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 545                                         cfile->srch_inf.entries_in_buffer;
 546
 547         /*
 548          * If first entry in buf is zero then is first buffer
 549          * in search response data which means it is likely . and ..
 550          * will be in this buffer, although some servers do not return
 551          * . and .. for the root of a drive and for those we need
 552          * to start two entries earlier.
 553          */
 554
 555         dump_cifs_file_struct(file, "In fce ");
 556         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 557              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 558                 /* close and restart search */
 559                 cFYI(1, "search backing up - close and restart search");
 560                 spin_lock(&cifs_file_list_lock);
 561                 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
 562                         cfile->invalidHandle = true;
 563                         spin_unlock(&cifs_file_list_lock);
 564                         if (server->ops->close)
 565                                 server->ops->close(xid, tcon, &cfile->fid);
 566                 } else
 567                         spin_unlock(&cifs_file_list_lock);
 568                 if (cfile->srch_inf.ntwrk_buf_start) {
 569                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 570                         if (cfile->srch_inf.smallBuf)
 571                                 cifs_small_buf_release(cfile->srch_inf.
 572                                                 ntwrk_buf_start);
 573                         else
 574                                 cifs_buf_release(cfile->srch_inf.
 575                                                 ntwrk_buf_start);
 576                         cfile->srch_inf.ntwrk_buf_start = NULL;
 577                 }
 578                 rc = initiate_cifs_search(xid, file);
 579                 if (rc) {
 580                         cFYI(1, "error %d reinitiating a search on rewind",
 581                                  rc);
 582                         return rc;
 583                 }
 584                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 585                 if (cfile->srch_inf.last_entry)
 586                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 587         }
 588
 589         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 590         if (backup_cred(cifs_sb))
 591                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 592
 593         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 594                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 595                 cFYI(1, "calling findnext2");
 596                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 597                                                  search_flags,
 598                                                  &cfile->srch_inf);
 599                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 600                 if (cfile->srch_inf.last_entry)
 601                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 602                 if (rc)
 603                         return -ENOENT;
 604         }
 605         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 606                 /* we found the buffer that contains the entry */
 607                 /* scan and find it */
 608                 int i;
 609                 char *cur_ent;
 610                 char *end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 611                         server->ops->calc_smb_size(
 612                                         cfile->srch_inf.ntwrk_buf_start);
 613
 614                 cur_ent = cfile->srch_inf.srch_entries_start;
 615                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 616                                         - cfile->srch_inf.entries_in_buffer;
 617                 pos_in_buf = index_to_find - first_entry_in_buffer;
 618                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 619
 620                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 621                         /* go entry by entry figuring out which is first */
 622                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 623                                                 cfile->srch_inf.info_level);
 624                 }
 625                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 626                         /* BB fixme - check if we should flag this error */
 627                         cERROR(1, "reached end of buf searching for pos in buf"
 628                                   " %d index to find %lld rc %d", pos_in_buf,
 629                                   index_to_find, rc);
 630                 }
 631                 rc = 0;
 632                 *current_entry = cur_ent;
 633         } else {
 634                 cFYI(1, "index not in buffer - could not findnext into it");
 635                 return 0;
 636         }
 637
 638         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 639                 cFYI(1, "can not return entries pos_in_buf beyond last");
 640                 *num_to_ret = 0;
 641         } else
 642                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 643
 644         return rc;
 645 }
 646
 647 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 648                 void *dirent, char *scratch_buf, unsigned int max_len)
 649 {
 650         struct cifsFileInfo *file_info = file->private_data;
 651         struct super_block *sb = file->f_path.dentry->d_sb;
 652         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 653         struct cifs_dirent de = { NULL, };
 654         struct cifs_fattr fattr;
 655         struct dentry *dentry;
 656         struct qstr name;
 657         int rc = 0;
 658         ino_t ino;
 659
 660         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 661                               file_info->srch_inf.unicode);
 662         if (rc)
 663                 return rc;
 664
 665         if (de.namelen > max_len) {
 666                 cERROR(1, "bad search response length %zd past smb end",
 667                           de.namelen);
 668                 return -EINVAL;
 669         }
 670
 671         /* skip . and .. since we added them first */
 672         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 673                 return 0;
 674
 675         if (file_info->srch_inf.unicode) {
 676                 struct nls_table *nlt = cifs_sb->local_nls;
 677
 678                 name.name = scratch_buf;
 679                 name.len =
 680                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 681                                         UNICODE_NAME_MAX,
 682                                         min_t(size_t, de.namelen,
 683                                               (size_t)max_len), nlt,
 684                                         cifs_sb->mnt_cifs_flags &
 685                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 686                 name.len -= nls_nullsize(nlt);
 687         } else {
 688                 name.name = de.name;
 689                 name.len = de.namelen;
 690         }
 691
 692         switch (file_info->srch_inf.info_level) {
 693         case SMB_FIND_FILE_UNIX:
 694                 cifs_unix_basic_to_fattr(&fattr,
 695                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 696                                          cifs_sb);
 697                 break;
 698         case SMB_FIND_FILE_INFO_STANDARD:
 699                 cifs_std_info_to_fattr(&fattr,
 700                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 701                                        cifs_sb);
 702                 break;
 703         default:
 704                 cifs_dir_info_to_fattr(&fattr,
 705                                        (FILE_DIRECTORY_INFO *)find_entry,
 706                                        cifs_sb);
 707                 break;
 708         }
 709
 710         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 711                 fattr.cf_uniqueid = de.ino;
 712         } else {
 713                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 714                 cifs_autodisable_serverino(cifs_sb);
 715         }
 716
 717         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 718             CIFSCouldBeMFSymlink(&fattr))
 719                 /*
 720                  * trying to get the type and mode can be slow,
 721                  * so just call those regular files for now, and mark
 722                  * for reval
 723                  */
 724                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 725
 726         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 727         dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
 728
 729         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 730                      fattr.cf_dtype);
 731
 732         dput(dentry);
 733         return rc;
 734 }
 735
 736
 737 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 738 {
 739         int rc = 0;
 740         unsigned int xid;
 741         int i;
 742         struct cifs_tcon *tcon;
 743         struct cifsFileInfo *cifsFile = NULL;
 744         char *current_entry;
 745         int num_to_fill = 0;
 746         char *tmp_buf = NULL;
 747         char *end_of_smb;
 748         unsigned int max_len;
 749
 750         xid = get_xid();
 751
 752         /*
 753          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 754          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 755          */
 756         if (file->private_data == NULL) {
 757                 rc = initiate_cifs_search(xid, file);
 758                 cFYI(1, "initiate cifs search rc %d", rc);
 759                 if (rc)
 760                         goto rddir2_exit;
 761         }
 762
 763         switch ((int) file->f_pos) {
 764         case 0:
 765                 if (filldir(direntry, ".", 1, file->f_pos,
 766                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 767                         cERROR(1, "Filldir for current dir failed");
 768                         rc = -ENOMEM;
 769                         break;
 770                 }
 771                 file->f_pos++;
 772         case 1:
 773                 if (filldir(direntry, "..", 2, file->f_pos,
 774                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 775                         cERROR(1, "Filldir for parent dir failed");
 776                         rc = -ENOMEM;
 777                         break;
 778                 }
 779                 file->f_pos++;
 780         default:
 781                 /* 1) If search is active,
 782                         is in current search buffer?
 783                         if it before then restart search
 784                         if after then keep searching till find it */
 785
 786                 if (file->private_data == NULL) {
 787                         rc = -EINVAL;
 788                         free_xid(xid);
 789                         return rc;
 790                 }
 791                 cifsFile = file->private_data;
 792                 if (cifsFile->srch_inf.endOfSearch) {
 793                         if (cifsFile->srch_inf.emptyDir) {
 794                                 cFYI(1, "End of search, empty dir");
 795                                 rc = 0;
 796                                 break;
 797                         }
 798                 } /* else {
 799                         cifsFile->invalidHandle = true;
 800                         tcon->ses->server->close(xid, tcon, &cifsFile->fid);
 801                 } */
 802
 803                 tcon = tlink_tcon(cifsFile->tlink);
 804                 rc = find_cifs_entry(xid, tcon, file, &current_entry,
 805                                      &num_to_fill);
 806                 if (rc) {
 807                         cFYI(1, "fce error %d", rc);
 808                         goto rddir2_exit;
 809                 } else if (current_entry != NULL) {
 810                         cFYI(1, "entry %lld found", file->f_pos);
 811                 } else {
 812                         cFYI(1, "could not find entry");
 813                         goto rddir2_exit;
 814                 }
 815                 cFYI(1, "loop through %d times filling dir for net buf %p",
 816                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 817                 max_len = tcon->ses->server->ops->calc_smb_size(
 818                                 cifsFile->srch_inf.ntwrk_buf_start);
 819                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 820
 821                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 822                 if (tmp_buf == NULL) {
 823                         rc = -ENOMEM;
 824                         break;
 825                 }
 826
 827                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 828                         if (current_entry == NULL) {
 829                                 /* evaluate whether this case is an error */
 830                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 831                                           num_to_fill, i);
 832                                 break;
 833                         }
 834                         /*
 835                          * if buggy server returns . and .. late do we want to
 836                          * check for that here?
 837                          */
 838                         rc = cifs_filldir(current_entry, file, filldir,
 839                                           direntry, tmp_buf, max_len);
 840                         if (rc == -EOVERFLOW) {
 841                                 rc = 0;
 842                                 break;
 843                         }
 844
 845                         file->f_pos++;
 846                         if (file->f_pos ==
 847                                 cifsFile->srch_inf.index_of_last_entry) {
 848                                 cFYI(1, "last entry in buf at pos %lld %s",
 849                                         file->f_pos, tmp_buf);
 850                                 cifs_save_resume_key(current_entry, cifsFile);
 851                                 break;
 852                         } else
 853                                 current_entry =
 854                                         nxt_dir_entry(current_entry, end_of_smb,
 855                                                 cifsFile->srch_inf.info_level);
 856                 }
 857                 kfree(tmp_buf);
 858                 break;
 859         } /* end switch */
 860
 861 rddir2_exit:
 862         free_xid(xid);
 863         return rc;
 864 }