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