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  * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
  70  *
  71  * Find the dentry that matches "name". If there isn't one, create one. If it's
  72  * a negative dentry or the uniqueid changed, then drop it and recreate it.
  73  */
  74 static void
  75 cifs_prime_dcache(struct dentry *parent, struct qstr *name,
  76                     struct cifs_fattr *fattr)
  77 {
  78         struct dentry *dentry, *alias;
  79         struct inode *inode;
  80         struct super_block *sb = parent->d_inode->i_sb;
  81
  82         cFYI(1, "%s: for %s", __func__, name->name);
  83
  84         if (parent->d_op && parent->d_op->d_hash)
  85                 parent->d_op->d_hash(parent, parent->d_inode, name);
  86         else
  87                 name->hash = full_name_hash(name->name, name->len);
  88
  89         dentry = d_lookup(parent, name);
  90         if (dentry) {
  91                 int err;
  92
  93                 inode = dentry->d_inode;
  94                 /* update inode in place if i_ino didn't change */
  95                 if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
  96                         cifs_fattr_to_inode(inode, fattr);
  97                         goto out;
  98                 }
  99                 err = d_invalidate(dentry);
 100                 dput(dentry);
 101                 if (err)
 102                         return;
 103         }
 104
 105         dentry = d_alloc(parent, name);
 106         if (!dentry)
 107                 return;
 108
 109         inode = cifs_iget(sb, fattr);
 110         if (!inode)
 111                 goto out;
 112
 113         alias = d_materialise_unique(dentry, inode);
 114         if (alias && !IS_ERR(alias))
 115                 dput(alias);
 116 out:
 117         dput(dentry);
 118 }
 119
 120 static void
 121 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 122 {
 123         fattr->cf_uid = cifs_sb->mnt_uid;
 124         fattr->cf_gid = cifs_sb->mnt_gid;
 125
 126         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 127                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 128                 fattr->cf_dtype = DT_DIR;
 129         } else {
 130                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 131                 fattr->cf_dtype = DT_REG;
 132         }
 133
 134         if (fattr->cf_cifsattrs & ATTR_READONLY)
 135                 fattr->cf_mode &= ~S_IWUGO;
 136
 137         /*
 138          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 139          * mark it for revalidation so that "ls -l" will look right. It might
 140          * be super-slow, but if we don't do this then the ownership of files
 141          * may look wrong since the inodes may not have timed out by the time
 142          * "ls" does a stat() call on them.
 143          */
 144         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
 145                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 146
 147         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 148             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 149                 if (fattr->cf_eof == 0)  {
 150                         fattr->cf_mode &= ~S_IFMT;
 151                         fattr->cf_mode |= S_IFIFO;
 152                         fattr->cf_dtype = DT_FIFO;
 153                 } else {
 154                         /*
 155                          * trying to get the type and mode via SFU can be slow,
 156                          * so just call those regular files for now, and mark
 157                          * for reval
 158                          */
 159                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 160                 }
 161         }
 162 }
 163
 164 void
 165 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 166                        struct cifs_sb_info *cifs_sb)
 167 {
 168         memset(fattr, 0, sizeof(*fattr));
 169         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 170         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 171         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 172         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 173         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 174         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 175         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 176
 177         cifs_fill_common_info(fattr, cifs_sb);
 178 }
 179
 180 static void
 181 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 182                        struct cifs_sb_info *cifs_sb)
 183 {
 184         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 185
 186         memset(fattr, 0, sizeof(*fattr));
 187         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 188                                             info->LastAccessTime, offset);
 189         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 190                                             info->LastWriteTime, offset);
 191         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 192                                             info->LastWriteTime, offset);
 193
 194         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 195         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 196         fattr->cf_eof = le32_to_cpu(info->DataSize);
 197
 198         cifs_fill_common_info(fattr, cifs_sb);
 199 }
 200
 201 /* BB eventually need to add the following helper function to
 202       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 203       we try to do FindFirst on (NTFS) directory symlinks */
 204 /*
 205 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 206                              unsigned int xid)
 207 {
 208         __u16 fid;
 209         int len;
 210         int oplock = 0;
 211         int rc;
 212         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 213         char *tmpbuffer;
 214
 215         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 216                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 217                         cifs_sb->local_nls,
 218                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 219         if (!rc) {
 220                 tmpbuffer = kmalloc(maxpath);
 221                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 222                                 tmpbuffer,
 223                                 maxpath -1,
 224                                 fid,
 225                                 cifs_sb->local_nls);
 226                 if (CIFSSMBClose(xid, ptcon, fid)) {
 227                         cFYI(1, "Error closing temporary reparsepoint open");
 228                 }
 229         }
 230 }
 231  */
 232
 233 static int
 234 initiate_cifs_search(const unsigned int xid, struct file *file)
 235 {
 236         __u16 search_flags;
 237         int rc = 0;
 238         char *full_path = NULL;
 239         struct cifsFileInfo *cifsFile;
 240         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 241         struct tcon_link *tlink = NULL;
 242         struct cifs_tcon *tcon;
 243         struct TCP_Server_Info *server;
 244
 245         if (file->private_data == NULL) {
 246                 tlink = cifs_sb_tlink(cifs_sb);
 247                 if (IS_ERR(tlink))
 248                         return PTR_ERR(tlink);
 249
 250                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 251                 if (cifsFile == NULL) {
 252                         rc = -ENOMEM;
 253                         goto error_exit;
 254                 }
 255                 file->private_data = cifsFile;
 256                 cifsFile->tlink = cifs_get_tlink(tlink);
 257                 tcon = tlink_tcon(tlink);
 258         } else {
 259                 cifsFile = file->private_data;
 260                 tcon = tlink_tcon(cifsFile->tlink);
 261         }
 262
 263         server = tcon->ses->server;
 264
 265         if (!server->ops->query_dir_first) {
 266                 rc = -ENOSYS;
 267                 goto error_exit;
 268         }
 269
 270         cifsFile->invalidHandle = true;
 271         cifsFile->srch_inf.endOfSearch = false;
 272
 273         full_path = build_path_from_dentry(file->f_path.dentry);
 274         if (full_path == NULL) {
 275                 rc = -ENOMEM;
 276                 goto error_exit;
 277         }
 278
 279         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 280
 281 ffirst_retry:
 282         /* test for Unix extensions */
 283         /* but now check for them on the share/mount not on the SMB session */
 284         /* if (cap_unix(tcon->ses) { */
 285         if (tcon->unix_ext)
 286                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 287         else if ((tcon->ses->capabilities &
 288                   tcon->ses->server->vals->cap_nt_find) == 0) {
 289                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 290         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 291                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 292         } else /* not srvinos - BB fixme add check for backlevel? */ {
 293                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 294         }
 295
 296         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 297         if (backup_cred(cifs_sb))
 298                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 299
 300         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 301                                           &cifsFile->fid, search_flags,
 302                                           &cifsFile->srch_inf);
 303
 304         if (rc == 0)
 305                 cifsFile->invalidHandle = false;
 306         /* BB add following call to handle readdir on new NTFS symlink errors
 307         else if STATUS_STOPPED_ON_SYMLINK
 308                 call get_symlink_reparse_path and retry with new path */
 309         else if ((rc == -EOPNOTSUPP) &&
 310                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 311                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 312                 goto ffirst_retry;
 313         }
 314 error_exit:
 315         kfree(full_path);
 316         cifs_put_tlink(tlink);
 317         return rc;
 318 }
 319
 320 /* return length of unicode string in bytes */
 321 static int cifs_unicode_bytelen(const char *str)
 322 {
 323         int len;
 324         const __le16 *ustr = (const __le16 *)str;
 325
 326         for (len = 0; len <= PATH_MAX; len++) {
 327                 if (ustr[len] == 0)
 328                         return len << 1;
 329         }
 330         cFYI(1, "Unicode string longer than PATH_MAX found");
 331         return len << 1;
 332 }
 333
 334 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 335 {
 336         char *new_entry;
 337         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 338
 339         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 340                 FIND_FILE_STANDARD_INFO *pfData;
 341                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 342
 343                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 344                                 pfData->FileNameLength;
 345         } else
 346                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 347         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 348         /* validate that new_entry is not past end of SMB */
 349         if (new_entry >= end_of_smb) {
 350                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 351                         new_entry, end_of_smb, old_entry);
 352                 return NULL;
 353         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 354                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 355                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 356                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 357                 cERROR(1, "search entry %p extends after end of SMB %p",
 358                         new_entry, end_of_smb);
 359                 return NULL;
 360         } else
 361                 return new_entry;
 362
 363 }
 364
 365 struct cifs_dirent {
 366         const char      *name;
 367         size_t          namelen;
 368         u32             resume_key;
 369         u64             ino;
 370 };
 371
 372 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 373                 const FILE_UNIX_INFO *info, bool is_unicode)
 374 {
 375         de->name = &info->FileName[0];
 376         if (is_unicode)
 377                 de->namelen = cifs_unicode_bytelen(de->name);
 378         else
 379                 de->namelen = strnlen(de->name, PATH_MAX);
 380         de->resume_key = info->ResumeKey;
 381         de->ino = le64_to_cpu(info->basic.UniqueId);
 382 }
 383
 384 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 385                 const FILE_DIRECTORY_INFO *info)
 386 {
 387         de->name = &info->FileName[0];
 388         de->namelen = le32_to_cpu(info->FileNameLength);
 389         de->resume_key = info->FileIndex;
 390 }
 391
 392 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 393                 const FILE_FULL_DIRECTORY_INFO *info)
 394 {
 395         de->name = &info->FileName[0];
 396         de->namelen = le32_to_cpu(info->FileNameLength);
 397         de->resume_key = info->FileIndex;
 398 }
 399
 400 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 401                 const SEARCH_ID_FULL_DIR_INFO *info)
 402 {
 403         de->name = &info->FileName[0];
 404         de->namelen = le32_to_cpu(info->FileNameLength);
 405         de->resume_key = info->FileIndex;
 406         de->ino = le64_to_cpu(info->UniqueId);
 407 }
 408
 409 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 410                 const FILE_BOTH_DIRECTORY_INFO *info)
 411 {
 412         de->name = &info->FileName[0];
 413         de->namelen = le32_to_cpu(info->FileNameLength);
 414         de->resume_key = info->FileIndex;
 415 }
 416
 417 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 418                 const FIND_FILE_STANDARD_INFO *info)
 419 {
 420         de->name = &info->FileName[0];
 421         /* one byte length, no endianess conversion */
 422         de->namelen = info->FileNameLength;
 423         de->resume_key = info->ResumeKey;
 424 }
 425
 426 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 427                 u16 level, bool is_unicode)
 428 {
 429         memset(de, 0, sizeof(*de));
 430
 431         switch (level) {
 432         case SMB_FIND_FILE_UNIX:
 433                 cifs_fill_dirent_unix(de, info, is_unicode);
 434                 break;
 435         case SMB_FIND_FILE_DIRECTORY_INFO:
 436                 cifs_fill_dirent_dir(de, info);
 437                 break;
 438         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 439                 cifs_fill_dirent_full(de, info);
 440                 break;
 441         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 442                 cifs_fill_dirent_search(de, info);
 443                 break;
 444         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 445                 cifs_fill_dirent_both(de, info);
 446                 break;
 447         case SMB_FIND_FILE_INFO_STANDARD:
 448                 cifs_fill_dirent_std(de, info);
 449                 break;
 450         default:
 451                 cFYI(1, "Unknown findfirst level %d", level);
 452                 return -EINVAL;
 453         }
 454
 455         return 0;
 456 }
 457
 458 #define UNICODE_DOT cpu_to_le16(0x2e)
 459
 460 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 461 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 462 {
 463         int rc = 0;
 464
 465         if (!de->name)
 466                 return 0;
 467
 468         if (is_unicode) {
 469                 __le16 *ufilename = (__le16 *)de->name;
 470                 if (de->namelen == 2) {
 471                         /* check for . */
 472                         if (ufilename[0] == UNICODE_DOT)
 473                                 rc = 1;
 474                 } else if (de->namelen == 4) {
 475                         /* check for .. */
 476                         if (ufilename[0] == UNICODE_DOT &&
 477                             ufilename[1] == UNICODE_DOT)
 478                                 rc = 2;
 479                 }
 480         } else /* ASCII */ {
 481                 if (de->namelen == 1) {
 482                         if (de->name[0] == '.')
 483                                 rc = 1;
 484                 } else if (de->namelen == 2) {
 485                         if (de->name[0] == '.' && de->name[1] == '.')
 486                                 rc = 2;
 487                 }
 488         }
 489
 490         return rc;
 491 }
 492
 493 /* Check if directory that we are searching has changed so we can decide
 494    whether we can use the cached search results from the previous search */
 495 static int is_dir_changed(struct file *file)
 496 {
 497         struct inode *inode = file->f_path.dentry->d_inode;
 498         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 499
 500         if (cifsInfo->time == 0)
 501                 return 1; /* directory was changed, perhaps due to unlink */
 502         else
 503                 return 0;
 504
 505 }
 506
 507 static int cifs_save_resume_key(const char *current_entry,
 508         struct cifsFileInfo *file_info)
 509 {
 510         struct cifs_dirent de;
 511         int rc;
 512
 513         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 514                               file_info->srch_inf.unicode);
 515         if (!rc) {
 516                 file_info->srch_inf.presume_name = de.name;
 517                 file_info->srch_inf.resume_name_len = de.namelen;
 518                 file_info->srch_inf.resume_key = de.resume_key;
 519         }
 520         return rc;
 521 }
 522
 523 /*
 524  * Find the corresponding entry in the search. Note that the SMB server returns
 525  * search entries for . and .. which complicates logic here if we choose to
 526  * parse for them and we do not assume that they are located in the findfirst
 527  * return buffer. We start counting in the buffer with entry 2 and increment for
 528  * every entry (do not increment for . or .. entry).
 529  */
 530 static int
 531 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon,
 532                 struct file *file, char **current_entry, int *num_to_ret)
 533 {
 534         __u16 search_flags;
 535         int rc = 0;
 536         int pos_in_buf = 0;
 537         loff_t first_entry_in_buffer;
 538         loff_t index_to_find = file->f_pos;
 539         struct cifsFileInfo *cfile = file->private_data;
 540         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 541         struct TCP_Server_Info *server = tcon->ses->server;
 542         /* check if index in the buffer */
 543
 544         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 545                 return -ENOSYS;
 546
 547         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 548                 return -ENOENT;
 549
 550         *current_entry = NULL;
 551         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 552                                         cfile->srch_inf.entries_in_buffer;
 553
 554         /*
 555          * If first entry in buf is zero then is first buffer
 556          * in search response data which means it is likely . and ..
 557          * will be in this buffer, although some servers do not return
 558          * . and .. for the root of a drive and for those we need
 559          * to start two entries earlier.
 560          */
 561
 562         dump_cifs_file_struct(file, "In fce ");
 563         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 564              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 565                 /* close and restart search */
 566                 cFYI(1, "search backing up - close and restart search");
 567                 spin_lock(&cifs_file_list_lock);
 568                 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
 569                         cfile->invalidHandle = true;
 570                         spin_unlock(&cifs_file_list_lock);
 571                         if (server->ops->close)
 572                                 server->ops->close(xid, tcon, &cfile->fid);
 573                 } else
 574                         spin_unlock(&cifs_file_list_lock);
 575                 if (cfile->srch_inf.ntwrk_buf_start) {
 576                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 577                         if (cfile->srch_inf.smallBuf)
 578                                 cifs_small_buf_release(cfile->srch_inf.
 579                                                 ntwrk_buf_start);
 580                         else
 581                                 cifs_buf_release(cfile->srch_inf.
 582                                                 ntwrk_buf_start);
 583                         cfile->srch_inf.ntwrk_buf_start = NULL;
 584                 }
 585                 rc = initiate_cifs_search(xid, file);
 586                 if (rc) {
 587                         cFYI(1, "error %d reinitiating a search on rewind",
 588                                  rc);
 589                         return rc;
 590                 }
 591                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 592                 if (cfile->srch_inf.last_entry)
 593                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 594         }
 595
 596         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 597         if (backup_cred(cifs_sb))
 598                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 599
 600         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 601                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 602                 cFYI(1, "calling findnext2");
 603                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 604                                                  search_flags,
 605                                                  &cfile->srch_inf);
 606                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 607                 if (cfile->srch_inf.last_entry)
 608                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 609                 if (rc)
 610                         return -ENOENT;
 611         }
 612         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 613                 /* we found the buffer that contains the entry */
 614                 /* scan and find it */
 615                 int i;
 616                 char *cur_ent;
 617                 char *end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 618                         server->ops->calc_smb_size(
 619                                         cfile->srch_inf.ntwrk_buf_start);
 620
 621                 cur_ent = cfile->srch_inf.srch_entries_start;
 622                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 623                                         - cfile->srch_inf.entries_in_buffer;
 624                 pos_in_buf = index_to_find - first_entry_in_buffer;
 625                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 626
 627                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 628                         /* go entry by entry figuring out which is first */
 629                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 630                                                 cfile->srch_inf.info_level);
 631                 }
 632                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 633                         /* BB fixme - check if we should flag this error */
 634                         cERROR(1, "reached end of buf searching for pos in buf"
 635                                   " %d index to find %lld rc %d", pos_in_buf,
 636                                   index_to_find, rc);
 637                 }
 638                 rc = 0;
 639                 *current_entry = cur_ent;
 640         } else {
 641                 cFYI(1, "index not in buffer - could not findnext into it");
 642                 return 0;
 643         }
 644
 645         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 646                 cFYI(1, "can not return entries pos_in_buf beyond last");
 647                 *num_to_ret = 0;
 648         } else
 649                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 650
 651         return rc;
 652 }
 653
 654 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 655                 void *dirent, char *scratch_buf, unsigned int max_len)
 656 {
 657         struct cifsFileInfo *file_info = file->private_data;
 658         struct super_block *sb = file->f_path.dentry->d_sb;
 659         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 660         struct cifs_dirent de = { NULL, };
 661         struct cifs_fattr fattr;
 662         struct qstr name;
 663         int rc = 0;
 664         ino_t ino;
 665
 666         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 667                               file_info->srch_inf.unicode);
 668         if (rc)
 669                 return rc;
 670
 671         if (de.namelen > max_len) {
 672                 cERROR(1, "bad search response length %zd past smb end",
 673                           de.namelen);
 674                 return -EINVAL;
 675         }
 676
 677         /* skip . and .. since we added them first */
 678         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 679                 return 0;
 680
 681         if (file_info->srch_inf.unicode) {
 682                 struct nls_table *nlt = cifs_sb->local_nls;
 683
 684                 name.name = scratch_buf;
 685                 name.len =
 686                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 687                                         UNICODE_NAME_MAX,
 688                                         min_t(size_t, de.namelen,
 689                                               (size_t)max_len), nlt,
 690                                         cifs_sb->mnt_cifs_flags &
 691                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 692                 name.len -= nls_nullsize(nlt);
 693         } else {
 694                 name.name = de.name;
 695                 name.len = de.namelen;
 696         }
 697
 698         switch (file_info->srch_inf.info_level) {
 699         case SMB_FIND_FILE_UNIX:
 700                 cifs_unix_basic_to_fattr(&fattr,
 701                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 702                                          cifs_sb);
 703                 break;
 704         case SMB_FIND_FILE_INFO_STANDARD:
 705                 cifs_std_info_to_fattr(&fattr,
 706                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 707                                        cifs_sb);
 708                 break;
 709         default:
 710                 cifs_dir_info_to_fattr(&fattr,
 711                                        (FILE_DIRECTORY_INFO *)find_entry,
 712                                        cifs_sb);
 713                 break;
 714         }
 715
 716         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 717                 fattr.cf_uniqueid = de.ino;
 718         } else {
 719                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 720                 cifs_autodisable_serverino(cifs_sb);
 721         }
 722
 723         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 724             CIFSCouldBeMFSymlink(&fattr))
 725                 /*
 726                  * trying to get the type and mode can be slow,
 727                  * so just call those regular files for now, and mark
 728                  * for reval
 729                  */
 730                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 731
 732         cifs_prime_dcache(file->f_dentry, &name, &fattr);
 733
 734         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 735         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 736                      fattr.cf_dtype);
 737         return rc;
 738 }
 739
 740
 741 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 742 {
 743         int rc = 0;
 744         unsigned int xid;
 745         int i;
 746         struct cifs_tcon *tcon;
 747         struct cifsFileInfo *cifsFile = NULL;
 748         char *current_entry;
 749         int num_to_fill = 0;
 750         char *tmp_buf = NULL;
 751         char *end_of_smb;
 752         unsigned int max_len;
 753
 754         xid = get_xid();
 755
 756         /*
 757          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 758          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 759          */
 760         if (file->private_data == NULL) {
 761                 rc = initiate_cifs_search(xid, file);
 762                 cFYI(1, "initiate cifs search rc %d", rc);
 763                 if (rc)
 764                         goto rddir2_exit;
 765         }
 766
 767         switch ((int) file->f_pos) {
 768         case 0:
 769                 if (filldir(direntry, ".", 1, file->f_pos,
 770                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 771                         cERROR(1, "Filldir for current dir failed");
 772                         rc = -ENOMEM;
 773                         break;
 774                 }
 775                 file->f_pos++;
 776         case 1:
 777                 if (filldir(direntry, "..", 2, file->f_pos,
 778                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 779                         cERROR(1, "Filldir for parent dir failed");
 780                         rc = -ENOMEM;
 781                         break;
 782                 }
 783                 file->f_pos++;
 784         default:
 785                 /* 1) If search is active,
 786                         is in current search buffer?
 787                         if it before then restart search
 788                         if after then keep searching till find it */
 789
 790                 if (file->private_data == NULL) {
 791                         rc = -EINVAL;
 792                         free_xid(xid);
 793                         return rc;
 794                 }
 795                 cifsFile = file->private_data;
 796                 if (cifsFile->srch_inf.endOfSearch) {
 797                         if (cifsFile->srch_inf.emptyDir) {
 798                                 cFYI(1, "End of search, empty dir");
 799                                 rc = 0;
 800                                 break;
 801                         }
 802                 } /* else {
 803                         cifsFile->invalidHandle = true;
 804                         tcon->ses->server->close(xid, tcon, &cifsFile->fid);
 805                 } */
 806
 807                 tcon = tlink_tcon(cifsFile->tlink);
 808                 rc = find_cifs_entry(xid, tcon, file, &current_entry,
 809                                      &num_to_fill);
 810                 if (rc) {
 811                         cFYI(1, "fce error %d", rc);
 812                         goto rddir2_exit;
 813                 } else if (current_entry != NULL) {
 814                         cFYI(1, "entry %lld found", file->f_pos);
 815                 } else {
 816                         cFYI(1, "could not find entry");
 817                         goto rddir2_exit;
 818                 }
 819                 cFYI(1, "loop through %d times filling dir for net buf %p",
 820                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 821                 max_len = tcon->ses->server->ops->calc_smb_size(
 822                                 cifsFile->srch_inf.ntwrk_buf_start);
 823                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 824
 825                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 826                 if (tmp_buf == NULL) {
 827                         rc = -ENOMEM;
 828                         break;
 829                 }
 830
 831                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 832                         if (current_entry == NULL) {
 833                                 /* evaluate whether this case is an error */
 834                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 835                                           num_to_fill, i);
 836                                 break;
 837                         }
 838                         /*
 839                          * if buggy server returns . and .. late do we want to
 840                          * check for that here?
 841                          */
 842                         rc = cifs_filldir(current_entry, file, filldir,
 843                                           direntry, tmp_buf, max_len);
 844                         if (rc == -EOVERFLOW) {
 845                                 rc = 0;
 846                                 break;
 847                         }
 848
 849                         file->f_pos++;
 850                         if (file->f_pos ==
 851                                 cifsFile->srch_inf.index_of_last_entry) {
 852                                 cFYI(1, "last entry in buf at pos %lld %s",
 853                                         file->f_pos, tmp_buf);
 854                                 cifs_save_resume_key(current_entry, cifsFile);
 855                                 break;
 856                         } else
 857                                 current_entry =
 858                                         nxt_dir_entry(current_entry, end_of_smb,
 859                                                 cifsFile->srch_inf.info_level);
 860                 }
 861                 kfree(tmp_buf);
 862                 break;
 863         } /* end switch */
 864
 865 rddir2_exit:
 866         free_xid(xid);
 867         return rc;
 868 }