fs/cifs/readdir.c

   1 /*
   2  *   fs/cifs/readdir.c
   3  *
   4  *   Directory search handling
   5  *
   6  *   Copyright (C) International Business Machines  Corp., 2004, 2008
   7  *   Copyright (C) Red Hat, Inc., 2011
   8  *   Author(s): Steve French (sfrench@us.ibm.com)
   9  *
  10  *   This library is free software; you can redistribute it and/or modify
  11  *   it under the terms of the GNU Lesser General Public License as published
  12  *   by the Free Software Foundation; either version 2.1 of the License, or
  13  *   (at your option) any later version.
  14  *
  15  *   This library is distributed in the hope that it will be useful,
  16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  18  *   the GNU Lesser General Public License for more details.
  19  *
  20  *   You should have received a copy of the GNU Lesser General Public License
  21  *   along with this library; if not, write to the Free Software
  22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24 #include <linux/fs.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/slab.h>
  27 #include <linux/stat.h>
  28 #include "cifspdu.h"
  29 #include "cifsglob.h"
  30 #include "cifsproto.h"
  31 #include "cifs_unicode.h"
  32 #include "cifs_debug.h"
  33 #include "cifs_fs_sb.h"
  34 #include "cifsfs.h"
  35
  36 /*
  37  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  38  * characters alloc more to account for such multibyte target UTF-8
  39  * characters.
  40  */
  41 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  42
  43 #ifdef CONFIG_CIFS_DEBUG2
  44 static void dump_cifs_file_struct(struct file *file, char *label)
  45 {
  46         struct cifsFileInfo *cf;
  47
  48         if (file) {
  49                 cf = file->private_data;
  50                 if (cf == NULL) {
  51                         cFYI(1, "empty cifs private file data");
  52                         return;
  53                 }
  54                 if (cf->invalidHandle)
  55                         cFYI(1, "invalid handle");
  56                 if (cf->srch_inf.endOfSearch)
  57                         cFYI(1, "end of search");
  58                 if (cf->srch_inf.emptyDir)
  59                         cFYI(1, "empty dir");
  60         }
  61 }
  62 #else
  63 static inline void dump_cifs_file_struct(struct file *file, char *label)
  64 {
  65 }
  66 #endif /* DEBUG2 */
  67
  68 /*
  69  * Find the dentry that matches "name". If there isn't one, create one. If it's
  70  * a negative dentry or the uniqueid changed, then drop it and recreate it.
  71  */
  72 static struct dentry *
  73 cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
  74                     struct cifs_fattr *fattr)
  75 {
  76         struct dentry *dentry, *alias;
  77         struct inode *inode;
  78         struct super_block *sb = parent->d_inode->i_sb;
  79
  80         cFYI(1, "For %s", name->name);
  81
  82         if (parent->d_op && parent->d_op->d_hash)
  83                 parent->d_op->d_hash(parent, parent->d_inode, name);
  84         else
  85                 name->hash = full_name_hash(name->name, name->len);
  86
  87         dentry = d_lookup(parent, name);
  88         if (dentry) {
  89                 inode = dentry->d_inode;
  90                 /* update inode in place if i_ino didn't change */
  91                 if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
  92                         cifs_fattr_to_inode(inode, fattr);
  93                         return dentry;
  94                 }
  95                 d_drop(dentry);
  96                 dput(dentry);
  97         }
  98
  99         dentry = d_alloc(parent, name);
 100         if (dentry == NULL)
 101                 return NULL;
 102
 103         inode = cifs_iget(sb, fattr);
 104         if (!inode) {
 105                 dput(dentry);
 106                 return NULL;
 107         }
 108
 109         alias = d_materialise_unique(dentry, inode);
 110         if (alias != NULL) {
 111                 dput(dentry);
 112                 if (IS_ERR(alias))
 113                         return NULL;
 114                 dentry = alias;
 115         }
 116
 117         return 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         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 138             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 139                 if (fattr->cf_eof == 0)  {
 140                         fattr->cf_mode &= ~S_IFMT;
 141                         fattr->cf_mode |= S_IFIFO;
 142                         fattr->cf_dtype = DT_FIFO;
 143                 } else {
 144                         /*
 145                          * trying to get the type and mode via SFU can be slow,
 146                          * so just call those regular files for now, and mark
 147                          * for reval
 148                          */
 149                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 150                 }
 151         }
 152 }
 153
 154 static void
 155 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 156                        struct cifs_sb_info *cifs_sb)
 157 {
 158         memset(fattr, 0, sizeof(*fattr));
 159         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 160         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 161         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 162         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 163         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 164         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 165         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 166
 167         cifs_fill_common_info(fattr, cifs_sb);
 168 }
 169
 170 static void
 171 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 172                        struct cifs_sb_info *cifs_sb)
 173 {
 174         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 175
 176         memset(fattr, 0, sizeof(*fattr));
 177         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 178                                             info->LastAccessTime, offset);
 179         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 180                                             info->LastWriteTime, offset);
 181         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 182                                             info->LastWriteTime, offset);
 183
 184         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 185         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 186         fattr->cf_eof = le32_to_cpu(info->DataSize);
 187
 188         cifs_fill_common_info(fattr, cifs_sb);
 189 }
 190
 191 /* BB eventually need to add the following helper function to
 192       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 193       we try to do FindFirst on (NTFS) directory symlinks */
 194 /*
 195 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 196                              unsigned int xid)
 197 {
 198         __u16 fid;
 199         int len;
 200         int oplock = 0;
 201         int rc;
 202         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 203         char *tmpbuffer;
 204
 205         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 206                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 207                         cifs_sb->local_nls,
 208                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 209         if (!rc) {
 210                 tmpbuffer = kmalloc(maxpath);
 211                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 212                                 tmpbuffer,
 213                                 maxpath -1,
 214                                 fid,
 215                                 cifs_sb->local_nls);
 216                 if (CIFSSMBClose(xid, ptcon, fid)) {
 217                         cFYI(1, "Error closing temporary reparsepoint open");
 218                 }
 219         }
 220 }
 221  */
 222
 223 static int initiate_cifs_search(const unsigned int xid, struct file *file)
 224 {
 225         __u16 search_flags;
 226         int rc = 0;
 227         char *full_path = NULL;
 228         struct cifsFileInfo *cifsFile;
 229         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 230         struct tcon_link *tlink = NULL;
 231         struct cifs_tcon *tcon;
 232
 233         if (file->private_data == NULL) {
 234                 tlink = cifs_sb_tlink(cifs_sb);
 235                 if (IS_ERR(tlink))
 236                         return PTR_ERR(tlink);
 237
 238                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 239                 if (cifsFile == NULL) {
 240                         rc = -ENOMEM;
 241                         goto error_exit;
 242                 }
 243                 file->private_data = cifsFile;
 244                 cifsFile->tlink = cifs_get_tlink(tlink);
 245                 tcon = tlink_tcon(tlink);
 246         } else {
 247                 cifsFile = file->private_data;
 248                 tcon = tlink_tcon(cifsFile->tlink);
 249         }
 250
 251         cifsFile->invalidHandle = true;
 252         cifsFile->srch_inf.endOfSearch = false;
 253
 254         full_path = build_path_from_dentry(file->f_path.dentry);
 255         if (full_path == NULL) {
 256                 rc = -ENOMEM;
 257                 goto error_exit;
 258         }
 259
 260         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 261
 262 ffirst_retry:
 263         /* test for Unix extensions */
 264         /* but now check for them on the share/mount not on the SMB session */
 265         /* if (cap_unix(tcon->ses) { */
 266         if (tcon->unix_ext)
 267                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 268         else if ((tcon->ses->capabilities &
 269                   tcon->ses->server->vals->cap_nt_find) == 0) {
 270                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 271         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 272                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 273         } else /* not srvinos - BB fixme add check for backlevel? */ {
 274                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 275         }
 276
 277         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 278         if (backup_cred(cifs_sb))
 279                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 280
 281         rc = CIFSFindFirst(xid, tcon, full_path, cifs_sb->local_nls,
 282                 &cifsFile->fid.netfid, search_flags, &cifsFile->srch_inf,
 283                 cifs_sb->mnt_cifs_flags &
 284                         CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
 285         if (rc == 0)
 286                 cifsFile->invalidHandle = false;
 287         /* BB add following call to handle readdir on new NTFS symlink errors
 288         else if STATUS_STOPPED_ON_SYMLINK
 289                 call get_symlink_reparse_path and retry with new path */
 290         else if ((rc == -EOPNOTSUPP) &&
 291                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 292                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 293                 goto ffirst_retry;
 294         }
 295 error_exit:
 296         kfree(full_path);
 297         cifs_put_tlink(tlink);
 298         return rc;
 299 }
 300
 301 /* return length of unicode string in bytes */
 302 static int cifs_unicode_bytelen(const char *str)
 303 {
 304         int len;
 305         const __le16 *ustr = (const __le16 *)str;
 306
 307         for (len = 0; len <= PATH_MAX; len++) {
 308                 if (ustr[len] == 0)
 309                         return len << 1;
 310         }
 311         cFYI(1, "Unicode string longer than PATH_MAX found");
 312         return len << 1;
 313 }
 314
 315 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 316 {
 317         char *new_entry;
 318         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 319
 320         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 321                 FIND_FILE_STANDARD_INFO *pfData;
 322                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 323
 324                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 325                                 pfData->FileNameLength;
 326         } else
 327                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 328         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 329         /* validate that new_entry is not past end of SMB */
 330         if (new_entry >= end_of_smb) {
 331                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 332                         new_entry, end_of_smb, old_entry);
 333                 return NULL;
 334         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 335                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 336                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 337                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 338                 cERROR(1, "search entry %p extends after end of SMB %p",
 339                         new_entry, end_of_smb);
 340                 return NULL;
 341         } else
 342                 return new_entry;
 343
 344 }
 345
 346 struct cifs_dirent {
 347         const char      *name;
 348         size_t          namelen;
 349         u32             resume_key;
 350         u64             ino;
 351 };
 352
 353 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 354                 const FILE_UNIX_INFO *info, bool is_unicode)
 355 {
 356         de->name = &info->FileName[0];
 357         if (is_unicode)
 358                 de->namelen = cifs_unicode_bytelen(de->name);
 359         else
 360                 de->namelen = strnlen(de->name, PATH_MAX);
 361         de->resume_key = info->ResumeKey;
 362         de->ino = le64_to_cpu(info->basic.UniqueId);
 363 }
 364
 365 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 366                 const FILE_DIRECTORY_INFO *info)
 367 {
 368         de->name = &info->FileName[0];
 369         de->namelen = le32_to_cpu(info->FileNameLength);
 370         de->resume_key = info->FileIndex;
 371 }
 372
 373 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 374                 const FILE_FULL_DIRECTORY_INFO *info)
 375 {
 376         de->name = &info->FileName[0];
 377         de->namelen = le32_to_cpu(info->FileNameLength);
 378         de->resume_key = info->FileIndex;
 379 }
 380
 381 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 382                 const SEARCH_ID_FULL_DIR_INFO *info)
 383 {
 384         de->name = &info->FileName[0];
 385         de->namelen = le32_to_cpu(info->FileNameLength);
 386         de->resume_key = info->FileIndex;
 387         de->ino = le64_to_cpu(info->UniqueId);
 388 }
 389
 390 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 391                 const FILE_BOTH_DIRECTORY_INFO *info)
 392 {
 393         de->name = &info->FileName[0];
 394         de->namelen = le32_to_cpu(info->FileNameLength);
 395         de->resume_key = info->FileIndex;
 396 }
 397
 398 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 399                 const FIND_FILE_STANDARD_INFO *info)
 400 {
 401         de->name = &info->FileName[0];
 402         /* one byte length, no endianess conversion */
 403         de->namelen = info->FileNameLength;
 404         de->resume_key = info->ResumeKey;
 405 }
 406
 407 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 408                 u16 level, bool is_unicode)
 409 {
 410         memset(de, 0, sizeof(*de));
 411
 412         switch (level) {
 413         case SMB_FIND_FILE_UNIX:
 414                 cifs_fill_dirent_unix(de, info, is_unicode);
 415                 break;
 416         case SMB_FIND_FILE_DIRECTORY_INFO:
 417                 cifs_fill_dirent_dir(de, info);
 418                 break;
 419         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 420                 cifs_fill_dirent_full(de, info);
 421                 break;
 422         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 423                 cifs_fill_dirent_search(de, info);
 424                 break;
 425         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 426                 cifs_fill_dirent_both(de, info);
 427                 break;
 428         case SMB_FIND_FILE_INFO_STANDARD:
 429                 cifs_fill_dirent_std(de, info);
 430                 break;
 431         default:
 432                 cFYI(1, "Unknown findfirst level %d", level);
 433                 return -EINVAL;
 434         }
 435
 436         return 0;
 437 }
 438
 439 #define UNICODE_DOT cpu_to_le16(0x2e)
 440
 441 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 442 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 443 {
 444         int rc = 0;
 445
 446         if (!de->name)
 447                 return 0;
 448
 449         if (is_unicode) {
 450                 __le16 *ufilename = (__le16 *)de->name;
 451                 if (de->namelen == 2) {
 452                         /* check for . */
 453                         if (ufilename[0] == UNICODE_DOT)
 454                                 rc = 1;
 455                 } else if (de->namelen == 4) {
 456                         /* check for .. */
 457                         if (ufilename[0] == UNICODE_DOT &&
 458                             ufilename[1] == UNICODE_DOT)
 459                                 rc = 2;
 460                 }
 461         } else /* ASCII */ {
 462                 if (de->namelen == 1) {
 463                         if (de->name[0] == '.')
 464                                 rc = 1;
 465                 } else if (de->namelen == 2) {
 466                         if (de->name[0] == '.' && de->name[1] == '.')
 467                                 rc = 2;
 468                 }
 469         }
 470
 471         return rc;
 472 }
 473
 474 /* Check if directory that we are searching has changed so we can decide
 475    whether we can use the cached search results from the previous search */
 476 static int is_dir_changed(struct file *file)
 477 {
 478         struct inode *inode = file->f_path.dentry->d_inode;
 479         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 480
 481         if (cifsInfo->time == 0)
 482                 return 1; /* directory was changed, perhaps due to unlink */
 483         else
 484                 return 0;
 485
 486 }
 487
 488 static int cifs_save_resume_key(const char *current_entry,
 489         struct cifsFileInfo *file_info)
 490 {
 491         struct cifs_dirent de;
 492         int rc;
 493
 494         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 495                               file_info->srch_inf.unicode);
 496         if (!rc) {
 497                 file_info->srch_inf.presume_name = de.name;
 498                 file_info->srch_inf.resume_name_len = de.namelen;
 499                 file_info->srch_inf.resume_key = de.resume_key;
 500         }
 501         return rc;
 502 }
 503
 504 /* find the corresponding entry in the search */
 505 /* Note that the SMB server returns search entries for . and .. which
 506    complicates logic here if we choose to parse for them and we do not
 507    assume that they are located in the findfirst return buffer.*/
 508 /* We start counting in the buffer with entry 2 and increment for every
 509    entry (do not increment for . or .. entry) */
 510 static int find_cifs_entry(const unsigned int xid, struct cifs_tcon *pTcon,
 511         struct file *file, char **ppCurrentEntry, int *num_to_ret)
 512 {
 513         __u16 search_flags;
 514         int rc = 0;
 515         int pos_in_buf = 0;
 516         loff_t first_entry_in_buffer;
 517         loff_t index_to_find = file->f_pos;
 518         struct cifsFileInfo *cifsFile = file->private_data;
 519         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 520         /* check if index in the buffer */
 521
 522         if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 523            (num_to_ret == NULL))
 524                 return -ENOENT;
 525
 526         *ppCurrentEntry = NULL;
 527         first_entry_in_buffer =
 528                 cifsFile->srch_inf.index_of_last_entry -
 529                         cifsFile->srch_inf.entries_in_buffer;
 530
 531         /* if first entry in buf is zero then is first buffer
 532         in search response data which means it is likely . and ..
 533         will be in this buffer, although some servers do not return
 534         . and .. for the root of a drive and for those we need
 535         to start two entries earlier */
 536
 537         dump_cifs_file_struct(file, "In fce ");
 538         if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 539              is_dir_changed(file)) ||
 540            (index_to_find < first_entry_in_buffer)) {
 541                 /* close and restart search */
 542                 cFYI(1, "search backing up - close and restart search");
 543                 spin_lock(&cifs_file_list_lock);
 544                 if (!cifsFile->srch_inf.endOfSearch &&
 545                     !cifsFile->invalidHandle) {
 546                         cifsFile->invalidHandle = true;
 547                         spin_unlock(&cifs_file_list_lock);
 548                         CIFSFindClose(xid, pTcon, cifsFile->fid.netfid);
 549                 } else
 550                         spin_unlock(&cifs_file_list_lock);
 551                 if (cifsFile->srch_inf.ntwrk_buf_start) {
 552                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 553                         if (cifsFile->srch_inf.smallBuf)
 554                                 cifs_small_buf_release(cifsFile->srch_inf.
 555                                                 ntwrk_buf_start);
 556                         else
 557                                 cifs_buf_release(cifsFile->srch_inf.
 558                                                 ntwrk_buf_start);
 559                         cifsFile->srch_inf.ntwrk_buf_start = NULL;
 560                 }
 561                 rc = initiate_cifs_search(xid, file);
 562                 if (rc) {
 563                         cFYI(1, "error %d reinitiating a search on rewind",
 564                                  rc);
 565                         return rc;
 566                 }
 567                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 568                 if (cifsFile->srch_inf.last_entry)
 569                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 570                                                 cifsFile);
 571         }
 572
 573         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 574         if (backup_cred(cifs_sb))
 575                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 576
 577         while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 578               (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 579                 cFYI(1, "calling findnext2");
 580                 rc = CIFSFindNext(xid, pTcon, cifsFile->fid.netfid,
 581                                   search_flags, &cifsFile->srch_inf);
 582                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 583                 if (cifsFile->srch_inf.last_entry)
 584                         cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 585                                                 cifsFile);
 586                 if (rc)
 587                         return -ENOENT;
 588         }
 589         if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 590                 /* we found the buffer that contains the entry */
 591                 /* scan and find it */
 592                 int i;
 593                 char *current_entry;
 594                 char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 595                         smbCalcSize((struct smb_hdr *)
 596                                 cifsFile->srch_inf.ntwrk_buf_start);
 597
 598                 current_entry = cifsFile->srch_inf.srch_entries_start;
 599                 first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 600                                         - cifsFile->srch_inf.entries_in_buffer;
 601                 pos_in_buf = index_to_find - first_entry_in_buffer;
 602                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 603
 604                 for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 605                         /* go entry by entry figuring out which is first */
 606                         current_entry = nxt_dir_entry(current_entry, end_of_smb,
 607                                                 cifsFile->srch_inf.info_level);
 608                 }
 609                 if ((current_entry == NULL) && (i < pos_in_buf)) {
 610                         /* BB fixme - check if we should flag this error */
 611                         cERROR(1, "reached end of buf searching for pos in buf"
 612                           " %d index to find %lld rc %d",
 613                           pos_in_buf, index_to_find, rc);
 614                 }
 615                 rc = 0;
 616                 *ppCurrentEntry = current_entry;
 617         } else {
 618                 cFYI(1, "index not in buffer - could not findnext into it");
 619                 return 0;
 620         }
 621
 622         if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 623                 cFYI(1, "can not return entries pos_in_buf beyond last");
 624                 *num_to_ret = 0;
 625         } else
 626                 *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 627
 628         return rc;
 629 }
 630
 631 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 632                 void *dirent, char *scratch_buf, unsigned int max_len)
 633 {
 634         struct cifsFileInfo *file_info = file->private_data;
 635         struct super_block *sb = file->f_path.dentry->d_sb;
 636         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 637         struct cifs_dirent de = { NULL, };
 638         struct cifs_fattr fattr;
 639         struct dentry *dentry;
 640         struct qstr name;
 641         int rc = 0;
 642         ino_t ino;
 643
 644         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 645                               file_info->srch_inf.unicode);
 646         if (rc)
 647                 return rc;
 648
 649         if (de.namelen > max_len) {
 650                 cERROR(1, "bad search response length %zd past smb end",
 651                           de.namelen);
 652                 return -EINVAL;
 653         }
 654
 655         /* skip . and .. since we added them first */
 656         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 657                 return 0;
 658
 659         if (file_info->srch_inf.unicode) {
 660                 struct nls_table *nlt = cifs_sb->local_nls;
 661
 662                 name.name = scratch_buf;
 663                 name.len =
 664                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 665                                         UNICODE_NAME_MAX,
 666                                         min_t(size_t, de.namelen,
 667                                               (size_t)max_len), nlt,
 668                                         cifs_sb->mnt_cifs_flags &
 669                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 670                 name.len -= nls_nullsize(nlt);
 671         } else {
 672                 name.name = de.name;
 673                 name.len = de.namelen;
 674         }
 675
 676         switch (file_info->srch_inf.info_level) {
 677         case SMB_FIND_FILE_UNIX:
 678                 cifs_unix_basic_to_fattr(&fattr,
 679                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 680                                          cifs_sb);
 681                 break;
 682         case SMB_FIND_FILE_INFO_STANDARD:
 683                 cifs_std_info_to_fattr(&fattr,
 684                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 685                                        cifs_sb);
 686                 break;
 687         default:
 688                 cifs_dir_info_to_fattr(&fattr,
 689                                        (FILE_DIRECTORY_INFO *)find_entry,
 690                                        cifs_sb);
 691                 break;
 692         }
 693
 694         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 695                 fattr.cf_uniqueid = de.ino;
 696         } else {
 697                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 698                 cifs_autodisable_serverino(cifs_sb);
 699         }
 700
 701         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 702             CIFSCouldBeMFSymlink(&fattr))
 703                 /*
 704                  * trying to get the type and mode can be slow,
 705                  * so just call those regular files for now, and mark
 706                  * for reval
 707                  */
 708                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 709
 710         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 711         dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
 712
 713         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 714                      fattr.cf_dtype);
 715
 716         dput(dentry);
 717         return rc;
 718 }
 719
 720
 721 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 722 {
 723         int rc = 0;
 724         unsigned int xid;
 725         int i;
 726         struct cifs_tcon *pTcon;
 727         struct cifsFileInfo *cifsFile = NULL;
 728         char *current_entry;
 729         int num_to_fill = 0;
 730         char *tmp_buf = NULL;
 731         char *end_of_smb;
 732         unsigned int max_len;
 733
 734         xid = get_xid();
 735
 736         /*
 737          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 738          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 739          */
 740         if (file->private_data == NULL) {
 741                 rc = initiate_cifs_search(xid, file);
 742                 cFYI(1, "initiate cifs search rc %d", rc);
 743                 if (rc)
 744                         goto rddir2_exit;
 745         }
 746
 747         switch ((int) file->f_pos) {
 748         case 0:
 749                 if (filldir(direntry, ".", 1, file->f_pos,
 750                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 751                         cERROR(1, "Filldir for current dir failed");
 752                         rc = -ENOMEM;
 753                         break;
 754                 }
 755                 file->f_pos++;
 756         case 1:
 757                 if (filldir(direntry, "..", 2, file->f_pos,
 758                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 759                         cERROR(1, "Filldir for parent dir failed");
 760                         rc = -ENOMEM;
 761                         break;
 762                 }
 763                 file->f_pos++;
 764         default:
 765                 /* 1) If search is active,
 766                         is in current search buffer?
 767                         if it before then restart search
 768                         if after then keep searching till find it */
 769
 770                 if (file->private_data == NULL) {
 771                         rc = -EINVAL;
 772                         free_xid(xid);
 773                         return rc;
 774                 }
 775                 cifsFile = file->private_data;
 776                 if (cifsFile->srch_inf.endOfSearch) {
 777                         if (cifsFile->srch_inf.emptyDir) {
 778                                 cFYI(1, "End of search, empty dir");
 779                                 rc = 0;
 780                                 break;
 781                         }
 782                 } /* else {
 783                         cifsFile->invalidHandle = true;
 784                         CIFSFindClose(xid, pTcon, cifsFile->fid.netfid);
 785                 } */
 786
 787                 pTcon = tlink_tcon(cifsFile->tlink);
 788                 rc = find_cifs_entry(xid, pTcon, file,
 789                                 &current_entry, &num_to_fill);
 790                 if (rc) {
 791                         cFYI(1, "fce error %d", rc);
 792                         goto rddir2_exit;
 793                 } else if (current_entry != NULL) {
 794                         cFYI(1, "entry %lld found", file->f_pos);
 795                 } else {
 796                         cFYI(1, "could not find entry");
 797                         goto rddir2_exit;
 798                 }
 799                 cFYI(1, "loop through %d times filling dir for net buf %p",
 800                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 801                 max_len = smbCalcSize((struct smb_hdr *)
 802                                 cifsFile->srch_inf.ntwrk_buf_start);
 803                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 804
 805                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 806                 if (tmp_buf == NULL) {
 807                         rc = -ENOMEM;
 808                         break;
 809                 }
 810
 811                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 812                         if (current_entry == NULL) {
 813                                 /* evaluate whether this case is an error */
 814                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 815                                           num_to_fill, i);
 816                                 break;
 817                         }
 818                         /* if buggy server returns . and .. late do
 819                         we want to check for that here? */
 820                         rc = cifs_filldir(current_entry, file,
 821                                         filldir, direntry, tmp_buf, max_len);
 822                         if (rc == -EOVERFLOW) {
 823                                 rc = 0;
 824                                 break;
 825                         }
 826
 827                         file->f_pos++;
 828                         if (file->f_pos ==
 829                                 cifsFile->srch_inf.index_of_last_entry) {
 830                                 cFYI(1, "last entry in buf at pos %lld %s",
 831                                         file->f_pos, tmp_buf);
 832                                 cifs_save_resume_key(current_entry, cifsFile);
 833                                 break;
 834                         } else
 835                                 current_entry =
 836                                         nxt_dir_entry(current_entry, end_of_smb,
 837                                                 cifsFile->srch_inf.info_level);
 838                 }
 839                 kfree(tmp_buf);
 840                 break;
 841         } /* end switch */
 842
 843 rddir2_exit:
 844         free_xid(xid);
 845         return rc;
 846 }