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         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
  82
  83         cFYI(1, "%s: for %s", __func__, name->name);
  84
  85         if (parent->d_op && parent->d_op->d_hash)
  86                 parent->d_op->d_hash(parent, parent->d_inode, name);
  87         else
  88                 name->hash = full_name_hash(name->name, name->len);
  89
  90         dentry = d_lookup(parent, name);
  91         if (dentry) {
  92                 int err;
  93
  94                 inode = dentry->d_inode;
  95                 if (inode) {
  96                         /*
  97                          * If we're generating inode numbers, then we don't
  98                          * want to clobber the existing one with the one that
  99                          * the readdir code created.
 100                          */
 101                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
 102                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
 103
 104                         /* update inode in place if i_ino didn't change */
 105                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
 106                                 cifs_fattr_to_inode(inode, fattr);
 107                                 goto out;
 108                         }
 109                 }
 110                 err = d_invalidate(dentry);
 111                 dput(dentry);
 112                 if (err)
 113                         return;
 114         }
 115
 116         dentry = d_alloc(parent, name);
 117         if (!dentry)
 118                 return;
 119
 120         inode = cifs_iget(sb, fattr);
 121         if (!inode)
 122                 goto out;
 123
 124         alias = d_materialise_unique(dentry, inode);
 125         if (alias && !IS_ERR(alias))
 126                 dput(alias);
 127 out:
 128         dput(dentry);
 129 }
 130
 131 static void
 132 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 133 {
 134         fattr->cf_uid = cifs_sb->mnt_uid;
 135         fattr->cf_gid = cifs_sb->mnt_gid;
 136
 137         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 138                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 139                 fattr->cf_dtype = DT_DIR;
 140         } else {
 141                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 142                 fattr->cf_dtype = DT_REG;
 143         }
 144
 145         if (fattr->cf_cifsattrs & ATTR_READONLY)
 146                 fattr->cf_mode &= ~S_IWUGO;
 147
 148         /*
 149          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 150          * mark it for revalidation so that "ls -l" will look right. It might
 151          * be super-slow, but if we don't do this then the ownership of files
 152          * may look wrong since the inodes may not have timed out by the time
 153          * "ls" does a stat() call on them.
 154          */
 155         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
 156                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 157
 158         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 159             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 160                 if (fattr->cf_eof == 0)  {
 161                         fattr->cf_mode &= ~S_IFMT;
 162                         fattr->cf_mode |= S_IFIFO;
 163                         fattr->cf_dtype = DT_FIFO;
 164                 } else {
 165                         /*
 166                          * trying to get the type and mode via SFU can be slow,
 167                          * so just call those regular files for now, and mark
 168                          * for reval
 169                          */
 170                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 171                 }
 172         }
 173 }
 174
 175 void
 176 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 177                        struct cifs_sb_info *cifs_sb)
 178 {
 179         memset(fattr, 0, sizeof(*fattr));
 180         fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 181         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 182         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 183         fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 184         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 185         fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 186         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 187
 188         cifs_fill_common_info(fattr, cifs_sb);
 189 }
 190
 191 static void
 192 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 193                        struct cifs_sb_info *cifs_sb)
 194 {
 195         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 196
 197         memset(fattr, 0, sizeof(*fattr));
 198         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 199                                             info->LastAccessTime, offset);
 200         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 201                                             info->LastWriteTime, offset);
 202         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 203                                             info->LastWriteTime, offset);
 204
 205         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 206         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 207         fattr->cf_eof = le32_to_cpu(info->DataSize);
 208
 209         cifs_fill_common_info(fattr, cifs_sb);
 210 }
 211
 212 /* BB eventually need to add the following helper function to
 213       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 214       we try to do FindFirst on (NTFS) directory symlinks */
 215 /*
 216 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 217                              unsigned int xid)
 218 {
 219         __u16 fid;
 220         int len;
 221         int oplock = 0;
 222         int rc;
 223         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 224         char *tmpbuffer;
 225
 226         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 227                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 228                         cifs_sb->local_nls,
 229                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 230         if (!rc) {
 231                 tmpbuffer = kmalloc(maxpath);
 232                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 233                                 tmpbuffer,
 234                                 maxpath -1,
 235                                 fid,
 236                                 cifs_sb->local_nls);
 237                 if (CIFSSMBClose(xid, ptcon, fid)) {
 238                         cFYI(1, "Error closing temporary reparsepoint open");
 239                 }
 240         }
 241 }
 242  */
 243
 244 static int
 245 initiate_cifs_search(const unsigned int xid, struct file *file)
 246 {
 247         __u16 search_flags;
 248         int rc = 0;
 249         char *full_path = NULL;
 250         struct cifsFileInfo *cifsFile;
 251         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 252         struct tcon_link *tlink = NULL;
 253         struct cifs_tcon *tcon;
 254         struct TCP_Server_Info *server;
 255
 256         if (file->private_data == NULL) {
 257                 tlink = cifs_sb_tlink(cifs_sb);
 258                 if (IS_ERR(tlink))
 259                         return PTR_ERR(tlink);
 260
 261                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 262                 if (cifsFile == NULL) {
 263                         rc = -ENOMEM;
 264                         goto error_exit;
 265                 }
 266                 file->private_data = cifsFile;
 267                 cifsFile->tlink = cifs_get_tlink(tlink);
 268                 tcon = tlink_tcon(tlink);
 269         } else {
 270                 cifsFile = file->private_data;
 271                 tcon = tlink_tcon(cifsFile->tlink);
 272         }
 273
 274         server = tcon->ses->server;
 275
 276         if (!server->ops->query_dir_first) {
 277                 rc = -ENOSYS;
 278                 goto error_exit;
 279         }
 280
 281         cifsFile->invalidHandle = true;
 282         cifsFile->srch_inf.endOfSearch = false;
 283
 284         full_path = build_path_from_dentry(file->f_path.dentry);
 285         if (full_path == NULL) {
 286                 rc = -ENOMEM;
 287                 goto error_exit;
 288         }
 289
 290         cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 291
 292 ffirst_retry:
 293         /* test for Unix extensions */
 294         /* but now check for them on the share/mount not on the SMB session */
 295         /* if (cap_unix(tcon->ses) { */
 296         if (tcon->unix_ext)
 297                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 298         else if ((tcon->ses->capabilities &
 299                   tcon->ses->server->vals->cap_nt_find) == 0) {
 300                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 301         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 302                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 303         } else /* not srvinos - BB fixme add check for backlevel? */ {
 304                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 305         }
 306
 307         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 308         if (backup_cred(cifs_sb))
 309                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 310
 311         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 312                                           &cifsFile->fid, search_flags,
 313                                           &cifsFile->srch_inf);
 314
 315         if (rc == 0)
 316                 cifsFile->invalidHandle = false;
 317         /* BB add following call to handle readdir on new NTFS symlink errors
 318         else if STATUS_STOPPED_ON_SYMLINK
 319                 call get_symlink_reparse_path and retry with new path */
 320         else if ((rc == -EOPNOTSUPP) &&
 321                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 322                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 323                 goto ffirst_retry;
 324         }
 325 error_exit:
 326         kfree(full_path);
 327         cifs_put_tlink(tlink);
 328         return rc;
 329 }
 330
 331 /* return length of unicode string in bytes */
 332 static int cifs_unicode_bytelen(const char *str)
 333 {
 334         int len;
 335         const __le16 *ustr = (const __le16 *)str;
 336
 337         for (len = 0; len <= PATH_MAX; len++) {
 338                 if (ustr[len] == 0)
 339                         return len << 1;
 340         }
 341         cFYI(1, "Unicode string longer than PATH_MAX found");
 342         return len << 1;
 343 }
 344
 345 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 346 {
 347         char *new_entry;
 348         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 349
 350         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 351                 FIND_FILE_STANDARD_INFO *pfData;
 352                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 353
 354                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 355                                 pfData->FileNameLength;
 356         } else
 357                 new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 358         cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 359         /* validate that new_entry is not past end of SMB */
 360         if (new_entry >= end_of_smb) {
 361                 cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 362                         new_entry, end_of_smb, old_entry);
 363                 return NULL;
 364         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 365                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 366                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 367                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 368                 cERROR(1, "search entry %p extends after end of SMB %p",
 369                         new_entry, end_of_smb);
 370                 return NULL;
 371         } else
 372                 return new_entry;
 373
 374 }
 375
 376 struct cifs_dirent {
 377         const char      *name;
 378         size_t          namelen;
 379         u32             resume_key;
 380         u64             ino;
 381 };
 382
 383 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 384                 const FILE_UNIX_INFO *info, bool is_unicode)
 385 {
 386         de->name = &info->FileName[0];
 387         if (is_unicode)
 388                 de->namelen = cifs_unicode_bytelen(de->name);
 389         else
 390                 de->namelen = strnlen(de->name, PATH_MAX);
 391         de->resume_key = info->ResumeKey;
 392         de->ino = le64_to_cpu(info->basic.UniqueId);
 393 }
 394
 395 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 396                 const FILE_DIRECTORY_INFO *info)
 397 {
 398         de->name = &info->FileName[0];
 399         de->namelen = le32_to_cpu(info->FileNameLength);
 400         de->resume_key = info->FileIndex;
 401 }
 402
 403 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 404                 const FILE_FULL_DIRECTORY_INFO *info)
 405 {
 406         de->name = &info->FileName[0];
 407         de->namelen = le32_to_cpu(info->FileNameLength);
 408         de->resume_key = info->FileIndex;
 409 }
 410
 411 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 412                 const SEARCH_ID_FULL_DIR_INFO *info)
 413 {
 414         de->name = &info->FileName[0];
 415         de->namelen = le32_to_cpu(info->FileNameLength);
 416         de->resume_key = info->FileIndex;
 417         de->ino = le64_to_cpu(info->UniqueId);
 418 }
 419
 420 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 421                 const FILE_BOTH_DIRECTORY_INFO *info)
 422 {
 423         de->name = &info->FileName[0];
 424         de->namelen = le32_to_cpu(info->FileNameLength);
 425         de->resume_key = info->FileIndex;
 426 }
 427
 428 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 429                 const FIND_FILE_STANDARD_INFO *info)
 430 {
 431         de->name = &info->FileName[0];
 432         /* one byte length, no endianess conversion */
 433         de->namelen = info->FileNameLength;
 434         de->resume_key = info->ResumeKey;
 435 }
 436
 437 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 438                 u16 level, bool is_unicode)
 439 {
 440         memset(de, 0, sizeof(*de));
 441
 442         switch (level) {
 443         case SMB_FIND_FILE_UNIX:
 444                 cifs_fill_dirent_unix(de, info, is_unicode);
 445                 break;
 446         case SMB_FIND_FILE_DIRECTORY_INFO:
 447                 cifs_fill_dirent_dir(de, info);
 448                 break;
 449         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 450                 cifs_fill_dirent_full(de, info);
 451                 break;
 452         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 453                 cifs_fill_dirent_search(de, info);
 454                 break;
 455         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 456                 cifs_fill_dirent_both(de, info);
 457                 break;
 458         case SMB_FIND_FILE_INFO_STANDARD:
 459                 cifs_fill_dirent_std(de, info);
 460                 break;
 461         default:
 462                 cFYI(1, "Unknown findfirst level %d", level);
 463                 return -EINVAL;
 464         }
 465
 466         return 0;
 467 }
 468
 469 #define UNICODE_DOT cpu_to_le16(0x2e)
 470
 471 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 472 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 473 {
 474         int rc = 0;
 475
 476         if (!de->name)
 477                 return 0;
 478
 479         if (is_unicode) {
 480                 __le16 *ufilename = (__le16 *)de->name;
 481                 if (de->namelen == 2) {
 482                         /* check for . */
 483                         if (ufilename[0] == UNICODE_DOT)
 484                                 rc = 1;
 485                 } else if (de->namelen == 4) {
 486                         /* check for .. */
 487                         if (ufilename[0] == UNICODE_DOT &&
 488                             ufilename[1] == UNICODE_DOT)
 489                                 rc = 2;
 490                 }
 491         } else /* ASCII */ {
 492                 if (de->namelen == 1) {
 493                         if (de->name[0] == '.')
 494                                 rc = 1;
 495                 } else if (de->namelen == 2) {
 496                         if (de->name[0] == '.' && de->name[1] == '.')
 497                                 rc = 2;
 498                 }
 499         }
 500
 501         return rc;
 502 }
 503
 504 /* Check if directory that we are searching has changed so we can decide
 505    whether we can use the cached search results from the previous search */
 506 static int is_dir_changed(struct file *file)
 507 {
 508         struct inode *inode = file->f_path.dentry->d_inode;
 509         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 510
 511         if (cifsInfo->time == 0)
 512                 return 1; /* directory was changed, perhaps due to unlink */
 513         else
 514                 return 0;
 515
 516 }
 517
 518 static int cifs_save_resume_key(const char *current_entry,
 519         struct cifsFileInfo *file_info)
 520 {
 521         struct cifs_dirent de;
 522         int rc;
 523
 524         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 525                               file_info->srch_inf.unicode);
 526         if (!rc) {
 527                 file_info->srch_inf.presume_name = de.name;
 528                 file_info->srch_inf.resume_name_len = de.namelen;
 529                 file_info->srch_inf.resume_key = de.resume_key;
 530         }
 531         return rc;
 532 }
 533
 534 /*
 535  * Find the corresponding entry in the search. Note that the SMB server returns
 536  * search entries for . and .. which complicates logic here if we choose to
 537  * parse for them and we do not assume that they are located in the findfirst
 538  * return buffer. We start counting in the buffer with entry 2 and increment for
 539  * every entry (do not increment for . or .. entry).
 540  */
 541 static int
 542 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon,
 543                 struct file *file, char **current_entry, int *num_to_ret)
 544 {
 545         __u16 search_flags;
 546         int rc = 0;
 547         int pos_in_buf = 0;
 548         loff_t first_entry_in_buffer;
 549         loff_t index_to_find = file->f_pos;
 550         struct cifsFileInfo *cfile = file->private_data;
 551         struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 552         struct TCP_Server_Info *server = tcon->ses->server;
 553         /* check if index in the buffer */
 554
 555         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 556                 return -ENOSYS;
 557
 558         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 559                 return -ENOENT;
 560
 561         *current_entry = NULL;
 562         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 563                                         cfile->srch_inf.entries_in_buffer;
 564
 565         /*
 566          * If first entry in buf is zero then is first buffer
 567          * in search response data which means it is likely . and ..
 568          * will be in this buffer, although some servers do not return
 569          * . and .. for the root of a drive and for those we need
 570          * to start two entries earlier.
 571          */
 572
 573         dump_cifs_file_struct(file, "In fce ");
 574         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 575              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 576                 /* close and restart search */
 577                 cFYI(1, "search backing up - close and restart search");
 578                 spin_lock(&cifs_file_list_lock);
 579                 if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
 580                         cfile->invalidHandle = true;
 581                         spin_unlock(&cifs_file_list_lock);
 582                         if (server->ops->close)
 583                                 server->ops->close(xid, tcon, &cfile->fid);
 584                 } else
 585                         spin_unlock(&cifs_file_list_lock);
 586                 if (cfile->srch_inf.ntwrk_buf_start) {
 587                         cFYI(1, "freeing SMB ff cache buf on search rewind");
 588                         if (cfile->srch_inf.smallBuf)
 589                                 cifs_small_buf_release(cfile->srch_inf.
 590                                                 ntwrk_buf_start);
 591                         else
 592                                 cifs_buf_release(cfile->srch_inf.
 593                                                 ntwrk_buf_start);
 594                         cfile->srch_inf.ntwrk_buf_start = NULL;
 595                 }
 596                 rc = initiate_cifs_search(xid, file);
 597                 if (rc) {
 598                         cFYI(1, "error %d reinitiating a search on rewind",
 599                                  rc);
 600                         return rc;
 601                 }
 602                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 603                 if (cfile->srch_inf.last_entry)
 604                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 605         }
 606
 607         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 608         if (backup_cred(cifs_sb))
 609                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 610
 611         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 612                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 613                 cFYI(1, "calling findnext2");
 614                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 615                                                  search_flags,
 616                                                  &cfile->srch_inf);
 617                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 618                 if (cfile->srch_inf.last_entry)
 619                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 620                 if (rc)
 621                         return -ENOENT;
 622         }
 623         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 624                 /* we found the buffer that contains the entry */
 625                 /* scan and find it */
 626                 int i;
 627                 char *cur_ent;
 628                 char *end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 629                         server->ops->calc_smb_size(
 630                                         cfile->srch_inf.ntwrk_buf_start);
 631
 632                 cur_ent = cfile->srch_inf.srch_entries_start;
 633                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 634                                         - cfile->srch_inf.entries_in_buffer;
 635                 pos_in_buf = index_to_find - first_entry_in_buffer;
 636                 cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 637
 638                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 639                         /* go entry by entry figuring out which is first */
 640                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 641                                                 cfile->srch_inf.info_level);
 642                 }
 643                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 644                         /* BB fixme - check if we should flag this error */
 645                         cERROR(1, "reached end of buf searching for pos in buf"
 646                                   " %d index to find %lld rc %d", pos_in_buf,
 647                                   index_to_find, rc);
 648                 }
 649                 rc = 0;
 650                 *current_entry = cur_ent;
 651         } else {
 652                 cFYI(1, "index not in buffer - could not findnext into it");
 653                 return 0;
 654         }
 655
 656         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 657                 cFYI(1, "can not return entries pos_in_buf beyond last");
 658                 *num_to_ret = 0;
 659         } else
 660                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 661
 662         return rc;
 663 }
 664
 665 static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 666                 void *dirent, char *scratch_buf, unsigned int max_len)
 667 {
 668         struct cifsFileInfo *file_info = file->private_data;
 669         struct super_block *sb = file->f_path.dentry->d_sb;
 670         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 671         struct cifs_dirent de = { NULL, };
 672         struct cifs_fattr fattr;
 673         struct qstr name;
 674         int rc = 0;
 675         ino_t ino;
 676
 677         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 678                               file_info->srch_inf.unicode);
 679         if (rc)
 680                 return rc;
 681
 682         if (de.namelen > max_len) {
 683                 cERROR(1, "bad search response length %zd past smb end",
 684                           de.namelen);
 685                 return -EINVAL;
 686         }
 687
 688         /* skip . and .. since we added them first */
 689         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 690                 return 0;
 691
 692         if (file_info->srch_inf.unicode) {
 693                 struct nls_table *nlt = cifs_sb->local_nls;
 694
 695                 name.name = scratch_buf;
 696                 name.len =
 697                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 698                                         UNICODE_NAME_MAX,
 699                                         min_t(size_t, de.namelen,
 700                                               (size_t)max_len), nlt,
 701                                         cifs_sb->mnt_cifs_flags &
 702                                                 CIFS_MOUNT_MAP_SPECIAL_CHR);
 703                 name.len -= nls_nullsize(nlt);
 704         } else {
 705                 name.name = de.name;
 706                 name.len = de.namelen;
 707         }
 708
 709         switch (file_info->srch_inf.info_level) {
 710         case SMB_FIND_FILE_UNIX:
 711                 cifs_unix_basic_to_fattr(&fattr,
 712                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 713                                          cifs_sb);
 714                 break;
 715         case SMB_FIND_FILE_INFO_STANDARD:
 716                 cifs_std_info_to_fattr(&fattr,
 717                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 718                                        cifs_sb);
 719                 break;
 720         default:
 721                 cifs_dir_info_to_fattr(&fattr,
 722                                        (FILE_DIRECTORY_INFO *)find_entry,
 723                                        cifs_sb);
 724                 break;
 725         }
 726
 727         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 728                 fattr.cf_uniqueid = de.ino;
 729         } else {
 730                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 731                 cifs_autodisable_serverino(cifs_sb);
 732         }
 733
 734         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 735             CIFSCouldBeMFSymlink(&fattr))
 736                 /*
 737                  * trying to get the type and mode can be slow,
 738                  * so just call those regular files for now, and mark
 739                  * for reval
 740                  */
 741                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 742
 743         cifs_prime_dcache(file->f_dentry, &name, &fattr);
 744
 745         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 746         rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 747                      fattr.cf_dtype);
 748         return rc;
 749 }
 750
 751
 752 int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 753 {
 754         int rc = 0;
 755         unsigned int xid;
 756         int i;
 757         struct cifs_tcon *tcon;
 758         struct cifsFileInfo *cifsFile = NULL;
 759         char *current_entry;
 760         int num_to_fill = 0;
 761         char *tmp_buf = NULL;
 762         char *end_of_smb;
 763         unsigned int max_len;
 764
 765         xid = get_xid();
 766
 767         /*
 768          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 769          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 770          */
 771         if (file->private_data == NULL) {
 772                 rc = initiate_cifs_search(xid, file);
 773                 cFYI(1, "initiate cifs search rc %d", rc);
 774                 if (rc)
 775                         goto rddir2_exit;
 776         }
 777
 778         switch ((int) file->f_pos) {
 779         case 0:
 780                 if (filldir(direntry, ".", 1, file->f_pos,
 781                      file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 782                         cERROR(1, "Filldir for current dir failed");
 783                         rc = -ENOMEM;
 784                         break;
 785                 }
 786                 file->f_pos++;
 787         case 1:
 788                 if (filldir(direntry, "..", 2, file->f_pos,
 789                      parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 790                         cERROR(1, "Filldir for parent dir failed");
 791                         rc = -ENOMEM;
 792                         break;
 793                 }
 794                 file->f_pos++;
 795         default:
 796                 /* 1) If search is active,
 797                         is in current search buffer?
 798                         if it before then restart search
 799                         if after then keep searching till find it */
 800
 801                 if (file->private_data == NULL) {
 802                         rc = -EINVAL;
 803                         free_xid(xid);
 804                         return rc;
 805                 }
 806                 cifsFile = file->private_data;
 807                 if (cifsFile->srch_inf.endOfSearch) {
 808                         if (cifsFile->srch_inf.emptyDir) {
 809                                 cFYI(1, "End of search, empty dir");
 810                                 rc = 0;
 811                                 break;
 812                         }
 813                 } /* else {
 814                         cifsFile->invalidHandle = true;
 815                         tcon->ses->server->close(xid, tcon, &cifsFile->fid);
 816                 } */
 817
 818                 tcon = tlink_tcon(cifsFile->tlink);
 819                 rc = find_cifs_entry(xid, tcon, file, &current_entry,
 820                                      &num_to_fill);
 821                 if (rc) {
 822                         cFYI(1, "fce error %d", rc);
 823                         goto rddir2_exit;
 824                 } else if (current_entry != NULL) {
 825                         cFYI(1, "entry %lld found", file->f_pos);
 826                 } else {
 827                         cFYI(1, "could not find entry");
 828                         goto rddir2_exit;
 829                 }
 830                 cFYI(1, "loop through %d times filling dir for net buf %p",
 831                         num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 832                 max_len = tcon->ses->server->ops->calc_smb_size(
 833                                 cifsFile->srch_inf.ntwrk_buf_start);
 834                 end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 835
 836                 tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 837                 if (tmp_buf == NULL) {
 838                         rc = -ENOMEM;
 839                         break;
 840                 }
 841
 842                 for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 843                         if (current_entry == NULL) {
 844                                 /* evaluate whether this case is an error */
 845                                 cERROR(1, "past SMB end,  num to fill %d i %d",
 846                                           num_to_fill, i);
 847                                 break;
 848                         }
 849                         /*
 850                          * if buggy server returns . and .. late do we want to
 851                          * check for that here?
 852                          */
 853                         rc = cifs_filldir(current_entry, file, filldir,
 854                                           direntry, tmp_buf, max_len);
 855                         if (rc == -EOVERFLOW) {
 856                                 rc = 0;
 857                                 break;
 858                         }
 859
 860                         file->f_pos++;
 861                         if (file->f_pos ==
 862                                 cifsFile->srch_inf.index_of_last_entry) {
 863                                 cFYI(1, "last entry in buf at pos %lld %s",
 864                                         file->f_pos, tmp_buf);
 865                                 cifs_save_resume_key(current_entry, cifsFile);
 866                                 break;
 867                         } else
 868                                 current_entry =
 869                                         nxt_dir_entry(current_entry, end_of_smb,
 870                                                 cifsFile->srch_inf.info_level);
 871                 }
 872                 kfree(tmp_buf);
 873                 break;
 874         } /* end switch */
 875
 876 rddir2_exit:
 877         free_xid(xid);
 878         return rc;
 879 }