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                         cifs_dbg(FYI, "empty cifs private file data\n");
  52                         return;
  53                 }
  54                 if (cf->invalidHandle)
  55                         cifs_dbg(FYI, "invalid handle\n");
  56                 if (cf->srch_inf.endOfSearch)
  57                         cifs_dbg(FYI, "end of search\n");
  58                 if (cf->srch_inf.emptyDir)
  59                         cifs_dbg(FYI, "empty dir\n");
  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         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
  82
  83         cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
  84
  85         dentry = d_hash_and_lookup(parent, name);
  86         if (unlikely(IS_ERR(dentry)))
  87                 return;
  88
  89         if (dentry) {
  90                 int err;
  91
  92                 inode = dentry->d_inode;
  93                 if (inode) {
  94                         /*
  95                          * If we're generating inode numbers, then we don't
  96                          * want to clobber the existing one with the one that
  97                          * the readdir code created.
  98                          */
  99                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
 100                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
 101
 102                         /* update inode in place if i_ino didn't change */
 103                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
 104                                 cifs_fattr_to_inode(inode, fattr);
 105                                 goto out;
 106                         }
 107                 }
 108                 err = d_invalidate(dentry);
 109                 dput(dentry);
 110                 if (err)
 111                         return;
 112         }
 113
 114         dentry = d_alloc(parent, name);
 115         if (!dentry)
 116                 return;
 117
 118         inode = cifs_iget(sb, fattr);
 119         if (!inode)
 120                 goto out;
 121
 122         alias = d_materialise_unique(dentry, inode);
 123         if (alias && !IS_ERR(alias))
 124                 dput(alias);
 125 out:
 126         dput(dentry);
 127 }
 128
 129 static void
 130 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 131 {
 132         fattr->cf_uid = cifs_sb->mnt_uid;
 133         fattr->cf_gid = cifs_sb->mnt_gid;
 134
 135         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 136                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 137                 fattr->cf_dtype = DT_DIR;
 138         } else {
 139                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 140                 fattr->cf_dtype = DT_REG;
 141         }
 142
 143         if (fattr->cf_cifsattrs & ATTR_READONLY)
 144                 fattr->cf_mode &= ~S_IWUGO;
 145
 146         /*
 147          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 148          * mark it for revalidation so that "ls -l" will look right. It might
 149          * be super-slow, but if we don't do this then the ownership of files
 150          * may look wrong since the inodes may not have timed out by the time
 151          * "ls" does a stat() call on them.
 152          */
 153         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
 154                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 155
 156         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 157             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 158                 if (fattr->cf_eof == 0)  {
 159                         fattr->cf_mode &= ~S_IFMT;
 160                         fattr->cf_mode |= S_IFIFO;
 161                         fattr->cf_dtype = DT_FIFO;
 162                 } else {
 163                         /*
 164                          * trying to get the type and mode via SFU can be slow,
 165                          * so just call those regular files for now, and mark
 166                          * for reval
 167                          */
 168                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 169                 }
 170         }
 171 }
 172
 173 void
 174 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 175                        struct cifs_sb_info *cifs_sb)
 176 {
 177         memset(fattr, 0, sizeof(*fattr));
 178         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 179         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 180         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 181         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 182         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 183         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 184         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 185
 186         cifs_fill_common_info(fattr, cifs_sb);
 187 }
 188
 189 static void
 190 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 191                        struct cifs_sb_info *cifs_sb)
 192 {
 193         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 194
 195         memset(fattr, 0, sizeof(*fattr));
 196         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 197                                             info->LastAccessTime, offset);
 198         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 199                                             info->LastWriteTime, offset);
 200         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 201                                             info->LastWriteTime, offset);
 202
 203         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 204         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 205         fattr->cf_eof = le32_to_cpu(info->DataSize);
 206
 207         cifs_fill_common_info(fattr, cifs_sb);
 208 }
 209
 210 /* BB eventually need to add the following helper function to
 211       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 212       we try to do FindFirst on (NTFS) directory symlinks */
 213 /*
 214 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 215                              unsigned int xid)
 216 {
 217         __u16 fid;
 218         int len;
 219         int oplock = 0;
 220         int rc;
 221         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 222         char *tmpbuffer;
 223
 224         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 225                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 226                         cifs_sb->local_nls,
 227                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 228         if (!rc) {
 229                 tmpbuffer = kmalloc(maxpath);
 230                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 231                                 tmpbuffer,
 232                                 maxpath -1,
 233                                 fid,
 234                                 cifs_sb->local_nls);
 235                 if (CIFSSMBClose(xid, ptcon, fid)) {
 236                         cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
 237                 }
 238         }
 239 }
 240  */
 241
 242 static int
 243 initiate_cifs_search(const unsigned int xid, struct file *file)
 244 {
 245         __u16 search_flags;
 246         int rc = 0;
 247         char *full_path = NULL;
 248         struct cifsFileInfo *cifsFile;
 249         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 250         struct tcon_link *tlink = NULL;
 251         struct cifs_tcon *tcon;
 252         struct TCP_Server_Info *server;
 253
 254         if (file->private_data == NULL) {
 255                 tlink = cifs_sb_tlink(cifs_sb);
 256                 if (IS_ERR(tlink))
 257                         return PTR_ERR(tlink);
 258
 259                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 260                 if (cifsFile == NULL) {
 261                         rc = -ENOMEM;
 262                         goto error_exit;
 263                 }
 264                 file->private_data = cifsFile;
 265                 cifsFile->tlink = cifs_get_tlink(tlink);
 266                 tcon = tlink_tcon(tlink);
 267         } else {
 268                 cifsFile = file->private_data;
 269                 tcon = tlink_tcon(cifsFile->tlink);
 270         }
 271
 272         server = tcon->ses->server;
 273
 274         if (!server->ops->query_dir_first) {
 275                 rc = -ENOSYS;
 276                 goto error_exit;
 277         }
 278
 279         cifsFile->invalidHandle = true;
 280         cifsFile->srch_inf.endOfSearch = false;
 281
 282         full_path = build_path_from_dentry(file->f_path.dentry);
 283         if (full_path == NULL) {
 284                 rc = -ENOMEM;
 285                 goto error_exit;
 286         }
 287
 288         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
 289
 290 ffirst_retry:
 291         /* test for Unix extensions */
 292         /* but now check for them on the share/mount not on the SMB session */
 293         /* if (cap_unix(tcon->ses) { */
 294         if (tcon->unix_ext)
 295                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 296         else if ((tcon->ses->capabilities &
 297                   tcon->ses->server->vals->cap_nt_find) == 0) {
 298                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 299         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 300                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 301         } else /* not srvinos - BB fixme add check for backlevel? */ {
 302                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 303         }
 304
 305         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 306         if (backup_cred(cifs_sb))
 307                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 308
 309         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 310                                           &cifsFile->fid, search_flags,
 311                                           &cifsFile->srch_inf);
 312
 313         if (rc == 0)
 314                 cifsFile->invalidHandle = false;
 315         /* BB add following call to handle readdir on new NTFS symlink errors
 316         else if STATUS_STOPPED_ON_SYMLINK
 317                 call get_symlink_reparse_path and retry with new path */
 318         else if ((rc == -EOPNOTSUPP) &&
 319                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 320                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 321                 goto ffirst_retry;
 322         }
 323 error_exit:
 324         kfree(full_path);
 325         cifs_put_tlink(tlink);
 326         return rc;
 327 }
 328
 329 /* return length of unicode string in bytes */
 330 static int cifs_unicode_bytelen(const char *str)
 331 {
 332         int len;
 333         const __le16 *ustr = (const __le16 *)str;
 334
 335         for (len = 0; len <= PATH_MAX; len++) {
 336                 if (ustr[len] == 0)
 337                         return len << 1;
 338         }
 339         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
 340         return len << 1;
 341 }
 342
 343 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 344 {
 345         char *new_entry;
 346         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 347
 348         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 349                 FIND_FILE_STANDARD_INFO *pfData;
 350                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 351
 352                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 353                                 pfData->FileNameLength;
 354         } else
 355                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 356         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
 357         /* validate that new_entry is not past end of SMB */
 358         if (new_entry >= end_of_smb) {
 359                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
 360                          new_entry, end_of_smb, old_entry);
 361                 return NULL;
 362         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 363                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 364                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 365                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 366                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
 367                          new_entry, end_of_smb);
 368                 return NULL;
 369         } else
 370                 return new_entry;
 371
 372 }
 373
 374 struct cifs_dirent {
 375         const char      *name;
 376         size_t          namelen;
 377         u32             resume_key;
 378         u64             ino;
 379 };
 380
 381 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 382                 const FILE_UNIX_INFO *info, bool is_unicode)
 383 {
 384         de->name = &info->FileName[0];
 385         if (is_unicode)
 386                 de->namelen = cifs_unicode_bytelen(de->name);
 387         else
 388                 de->namelen = strnlen(de->name, PATH_MAX);
 389         de->resume_key = info->ResumeKey;
 390         de->ino = le64_to_cpu(info->basic.UniqueId);
 391 }
 392
 393 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 394                 const FILE_DIRECTORY_INFO *info)
 395 {
 396         de->name = &info->FileName[0];
 397         de->namelen = le32_to_cpu(info->FileNameLength);
 398         de->resume_key = info->FileIndex;
 399 }
 400
 401 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 402                 const FILE_FULL_DIRECTORY_INFO *info)
 403 {
 404         de->name = &info->FileName[0];
 405         de->namelen = le32_to_cpu(info->FileNameLength);
 406         de->resume_key = info->FileIndex;
 407 }
 408
 409 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 410                 const SEARCH_ID_FULL_DIR_INFO *info)
 411 {
 412         de->name = &info->FileName[0];
 413         de->namelen = le32_to_cpu(info->FileNameLength);
 414         de->resume_key = info->FileIndex;
 415         de->ino = le64_to_cpu(info->UniqueId);
 416 }
 417
 418 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 419                 const FILE_BOTH_DIRECTORY_INFO *info)
 420 {
 421         de->name = &info->FileName[0];
 422         de->namelen = le32_to_cpu(info->FileNameLength);
 423         de->resume_key = info->FileIndex;
 424 }
 425
 426 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 427                 const FIND_FILE_STANDARD_INFO *info)
 428 {
 429         de->name = &info->FileName[0];
 430         /* one byte length, no endianess conversion */
 431         de->namelen = info->FileNameLength;
 432         de->resume_key = info->ResumeKey;
 433 }
 434
 435 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 436                 u16 level, bool is_unicode)
 437 {
 438         memset(de, 0, sizeof(*de));
 439
 440         switch (level) {
 441         case SMB_FIND_FILE_UNIX:
 442                 cifs_fill_dirent_unix(de, info, is_unicode);
 443                 break;
 444         case SMB_FIND_FILE_DIRECTORY_INFO:
 445                 cifs_fill_dirent_dir(de, info);
 446                 break;
 447         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 448                 cifs_fill_dirent_full(de, info);
 449                 break;
 450         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 451                 cifs_fill_dirent_search(de, info);
 452                 break;
 453         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 454                 cifs_fill_dirent_both(de, info);
 455                 break;
 456         case SMB_FIND_FILE_INFO_STANDARD:
 457                 cifs_fill_dirent_std(de, info);
 458                 break;
 459         default:
 460                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
 461                 return -EINVAL;
 462         }
 463
 464         return 0;
 465 }
 466
 467 #define UNICODE_DOT cpu_to_le16(0x2e)
 468
 469 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 470 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 471 {
 472         int rc = 0;
 473
 474         if (!de->name)
 475                 return 0;
 476
 477         if (is_unicode) {
 478                 __le16 *ufilename = (__le16 *)de->name;
 479                 if (de->namelen == 2) {
 480                         /* check for . */
 481                         if (ufilename[0] == UNICODE_DOT)
 482                                 rc = 1;
 483                 } else if (de->namelen == 4) {
 484                         /* check for .. */
 485                         if (ufilename[0] == UNICODE_DOT &&
 486                             ufilename[1] == UNICODE_DOT)
 487                                 rc = 2;
 488                 }
 489         } else /* ASCII */ {
 490                 if (de->namelen == 1) {
 491                         if (de->name[0] == '.')
 492                                 rc = 1;
 493                 } else if (de->namelen == 2) {
 494                         if (de->name[0] == '.' && de->name[1] == '.')
 495                                 rc = 2;
 496                 }
 497         }
 498
 499         return rc;
 500 }
 501
 502 /* Check if directory that we are searching has changed so we can decide
 503    whether we can use the cached search results from the previous search */
 504 static int is_dir_changed(struct file *file)
 505 {
 506         struct inode *inode = file_inode(file);
 507         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 508
 509         if (cifsInfo->time == 0)
 510                 return 1; /* directory was changed, perhaps due to unlink */
 511         else
 512                 return 0;
 513
 514 }
 515
 516 static int cifs_save_resume_key(const char *current_entry,
 517         struct cifsFileInfo *file_info)
 518 {
 519         struct cifs_dirent de;
 520         int rc;
 521
 522         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 523                               file_info->srch_inf.unicode);
 524         if (!rc) {
 525                 file_info->srch_inf.presume_name = de.name;
 526                 file_info->srch_inf.resume_name_len = de.namelen;
 527                 file_info->srch_inf.resume_key = de.resume_key;
 528         }
 529         return rc;
 530 }
 531
 532 /*
 533  * Find the corresponding entry in the search. Note that the SMB server returns
 534  * search entries for . and .. which complicates logic here if we choose to
 535  * parse for them and we do not assume that they are located in the findfirst
 536  * return buffer. We start counting in the buffer with entry 2 and increment for
 537  * every entry (do not increment for . or .. entry).
 538  */
 539 static int
 540 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon,
 541                 struct file *file, char **current_entry, int *num_to_ret)
 542 {
 543         __u16 search_flags;
 544         int rc = 0;
 545         int pos_in_buf = 0;
 546         loff_t first_entry_in_buffer;
 547         loff_t index_to_find = file->f_pos;
 548         struct cifsFileInfo *cfile = file->private_data;
 549         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 550         struct TCP_Server_Info *server = tcon->ses->server;
 551         /* check if index in the buffer */
 552
 553         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 554                 return -ENOSYS;
 555
 556         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 557                 return -ENOENT;
 558
 559         *current_entry = NULL;
 560         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 561                                         cfile->srch_inf.entries_in_buffer;
 562
 563         /*
 564          * If first entry in buf is zero then is first buffer
 565          * in search response data which means it is likely . and ..
 566          * will be in this buffer, although some servers do not return
 567          * . and .. for the root of a drive and for those we need
 568          * to start two entries earlier.
 569          */
 570
 571         dump_cifs_file_struct(file, "In fce ");
 572         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 573              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 574                 /* close and restart search */
 575                 cifs_dbg(FYI, "search backing up - close and restart search\n");
 576                 spin_lock(&cifs_file_list_lock);
 577                 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
 578                         cfile->invalidHandle = true;
 579                         spin_unlock(&cifs_file_list_lock);
 580                         if (server->ops->close)
 581                                 server->ops->close(xid, tcon, &cfile->fid);
 582                 } else
 583                         spin_unlock(&cifs_file_list_lock);
 584                 if (cfile->srch_inf.ntwrk_buf_start) {
 585                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
 586                         if (cfile->srch_inf.smallBuf)
 587                                 cifs_small_buf_release(cfile->srch_inf.
 588                                                 ntwrk_buf_start);
 589                         else
 590                                 cifs_buf_release(cfile->srch_inf.
 591                                                 ntwrk_buf_start);
 592                         cfile->srch_inf.ntwrk_buf_start = NULL;
 593                 }
 594                 rc = initiate_cifs_search(xid, file);
 595                 if (rc) {
 596                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
 597                                  rc);
 598                         return rc;
 599                 }
 600                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 601                 if (cfile->srch_inf.last_entry)
 602                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 603         }
 604
 605         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 606         if (backup_cred(cifs_sb))
 607                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 608
 609         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 610                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 611                 cifs_dbg(FYI, "calling findnext2\n");
 612                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 613                                                  search_flags,
 614                                                  &cfile->srch_inf);
 615                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 616                 if (cfile->srch_inf.last_entry)
 617                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 618                 if (rc)
 619                         return -ENOENT;
 620         }
 621         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 622                 /* we found the buffer that contains the entry */
 623                 /* scan and find it */
 624                 int i;
 625                 char *cur_ent;
 626                 char *end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 627                         server->ops->calc_smb_size(
 628                                         cfile->srch_inf.ntwrk_buf_start);
 629
 630                 cur_ent = cfile->srch_inf.srch_entries_start;
 631                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 632                                         - cfile->srch_inf.entries_in_buffer;
 633                 pos_in_buf = index_to_find - first_entry_in_buffer;
 634                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
 635
 636                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 637                         /* go entry by entry figuring out which is first */
 638                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 639                                                 cfile->srch_inf.info_level);
 640                 }
 641                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 642                         /* BB fixme - check if we should flag this error */
 643                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
 644                                  pos_in_buf, index_to_find, rc);
 645                 }
 646                 rc = 0;
 647                 *current_entry = cur_ent;
 648         } else {
 649                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
 650                 return 0;
 651         }
 652
 653         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 654                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
 655                 *num_to_ret = 0;
 656         } else
 657                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 658
 659         return rc;
 660 }
 661
 662 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 663                 void *dirent, char *scratch_buf, unsigned int max_len)
 664 {
 665         struct cifsFileInfo *file_info = file->private_data;
 666         struct super_block *sb = file->f_path.dentry->d_sb;
 667         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 668         struct cifs_dirent de = { NULL, };
 669         struct cifs_fattr fattr;
 670         struct qstr name;
 671         int rc = 0;
 672         ino_t ino;
 673
 674         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 675                               file_info->srch_inf.unicode);
 676         if (rc)
 677                 return rc;
 678
 679         if (de.namelen > max_len) {
 680                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
 681                          de.namelen);
 682                 return -EINVAL;
 683         }
 684
 685         /* skip . and .. since we added them first */
 686         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 687                 return 0;
 688
 689         if (file_info->srch_inf.unicode) {
 690                 struct nls_table *nlt = cifs_sb->local_nls;
 691
 692                 name.name = scratch_buf;
 693                 name.len =
 694                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 695                                         UNICODE_NAME_MAX,
 696                                         min_t(size_t, de.namelen,
 697                                               (size_t)max_len), nlt,
 698                                         cifs_sb->mnt_cifs_flags &
 699                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 700                 name.len -= nls_nullsize(nlt);
 701         } else {
 702                 name.name = de.name;
 703                 name.len = de.namelen;
 704         }
 705
 706         switch (file_info->srch_inf.info_level) {
 707         case SMB_FIND_FILE_UNIX:
 708                 cifs_unix_basic_to_fattr(&fattr,
 709                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 710                                          cifs_sb);
 711                 break;
 712         case SMB_FIND_FILE_INFO_STANDARD:
 713                 cifs_std_info_to_fattr(&fattr,
 714                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 715                                        cifs_sb);
 716                 break;
 717         default:
 718                 cifs_dir_info_to_fattr(&fattr,
 719                                        (FILE_DIRECTORY_INFO *)find_entry,
 720                                        cifs_sb);
 721                 break;
 722         }
 723
 724         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 725                 fattr.cf_uniqueid = de.ino;
 726         } else {
 727                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 728                 cifs_autodisable_serverino(cifs_sb);
 729         }
 730
 731         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 732             CIFSCouldBeMFSymlink(&fattr))
 733                 /*
 734                  * trying to get the type and mode can be slow,
 735                  * so just call those regular files for now, and mark
 736                  * for reval
 737                  */
 738                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 739
 740         cifs_prime_dcache(file->f_dentry, &name, &fattr);
 741
 742         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 743         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 744                      fattr.cf_dtype);
 745         return rc;
 746 }
 747
 748
 749 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 750 {
 751         int rc = 0;
 752         unsigned int xid;
 753         int i;
 754         struct cifs_tcon *tcon;
 755         struct cifsFileInfo *cifsFile = NULL;
 756         char *current_entry;
 757         int num_to_fill = 0;
 758         char *tmp_buf = NULL;
 759         char *end_of_smb;
 760         unsigned int max_len;
 761
 762         xid = get_xid();
 763
 764         /*
 765          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 766          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 767          */
 768         if (file->private_data == NULL) {
 769                 rc = initiate_cifs_search(xid, file);
 770                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
 771                 if (rc)
 772                         goto rddir2_exit;
 773         }
 774
 775         switch ((int) file->f_pos) {
 776         case 0:
 777                 if (filldir(direntry, ".", 1, file->f_pos,
 778                      file_inode(file)->i_ino, DT_DIR) < 0) {
 779                         cifs_dbg(VFS, "Filldir for current dir failed\n");
 780                         rc = -ENOMEM;
 781                         break;
 782                 }
 783                 file->f_pos++;
 784         case 1:
 785                 if (filldir(direntry, "..", 2, file->f_pos,
 786                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 787                         cifs_dbg(VFS, "Filldir for parent dir failed\n");
 788                         rc = -ENOMEM;
 789                         break;
 790                 }
 791                 file->f_pos++;
 792         default:
 793                 /* 1) If search is active,
 794                         is in current search buffer?
 795                         if it before then restart search
 796                         if after then keep searching till find it */
 797
 798                 if (file->private_data == NULL) {
 799                         rc = -EINVAL;
 800                         free_xid(xid);
 801                         return rc;
 802                 }
 803                 cifsFile = file->private_data;
 804                 if (cifsFile->srch_inf.endOfSearch) {
 805                         if (cifsFile->srch_inf.emptyDir) {
 806                                 cifs_dbg(FYI, "End of search, empty dir\n");
 807                                 rc = 0;
 808                                 break;
 809                         }
 810                 } /* else {
 811                         cifsFile->invalidHandle = true;
 812                         tcon->ses->server->close(xid, tcon, &cifsFile->fid);
 813                 } */
 814
 815                 tcon = tlink_tcon(cifsFile->tlink);
 816                 rc = find_cifs_entry(xid, tcon, file, &current_entry,
 817                                      &num_to_fill);
 818                 if (rc) {
 819                         cifs_dbg(FYI, "fce error %d\n", rc);
 820                         goto rddir2_exit;
 821                 } else if (current_entry != NULL) {
 822                         cifs_dbg(FYI, "entry %lld found\n", file->f_pos);
 823                 } else {
 824                         cifs_dbg(FYI, "could not find entry\n");
 825                         goto rddir2_exit;
 826                 }
 827                 cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
 828                          num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 829                 max_len = tcon->ses->server->ops->calc_smb_size(
 830                                 cifsFile->srch_inf.ntwrk_buf_start);
 831                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 832
 833                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 834                 if (tmp_buf == NULL) {
 835                         rc = -ENOMEM;
 836                         break;
 837                 }
 838
 839                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 840                         if (current_entry == NULL) {
 841                                 /* evaluate whether this case is an error */
 842                                 cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
 843                                          num_to_fill, i);
 844                                 break;
 845                         }
 846                         /*
 847                          * if buggy server returns . and .. late do we want to
 848                          * check for that here?
 849                          */
 850                         rc = cifs_filldir(current_entry, file, filldir,
 851                                           direntry, tmp_buf, max_len);
 852                         if (rc == -EOVERFLOW) {
 853                                 rc = 0;
 854                                 break;
 855                         }
 856
 857                         file->f_pos++;
 858                         if (file->f_pos ==
 859                                 cifsFile->srch_inf.index_of_last_entry) {
 860                                 cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
 861                                          file->f_pos, tmp_buf);
 862                                 cifs_save_resume_key(current_entry, cifsFile);
 863                                 break;
 864                         } else
 865                                 current_entry =
 866                                         nxt_dir_entry(current_entry, end_of_smb,
 867                                                 cifsFile->srch_inf.info_level);
 868                 }
 869                 kfree(tmp_buf);
 870                 break;
 871         } /* end switch */
 872
 873 rddir2_exit:
 874         free_xid(xid);
 875         return rc;
 876 }