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 #include "smb2proto.h"
  36
  37 /*
  38  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  39  * characters alloc more to account for such multibyte target UTF-8
  40  * characters.
  41  */
  42 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  43
  44 #ifdef CONFIG_CIFS_DEBUG2
  45 static void dump_cifs_file_struct(struct file *file, char *label)
  46 {
  47         struct cifsFileInfo *cf;
  48
  49         if (file) {
  50                 cf = file->private_data;
  51                 if (cf == NULL) {
  52                         cifs_dbg(FYI, "empty cifs private file data\n");
  53                         return;
  54                 }
  55                 if (cf->invalidHandle)
  56                         cifs_dbg(FYI, "invalid handle\n");
  57                 if (cf->srch_inf.endOfSearch)
  58                         cifs_dbg(FYI, "end of search\n");
  59                 if (cf->srch_inf.emptyDir)
  60                         cifs_dbg(FYI, "empty dir\n");
  61         }
  62 }
  63 #else
  64 static inline void dump_cifs_file_struct(struct file *file, char *label)
  65 {
  66 }
  67 #endif /* DEBUG2 */
  68
  69 /*
  70  * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
  71  *
  72  * Find the dentry that matches "name". If there isn't one, create one. If it's
  73  * a negative dentry or the uniqueid or filetype(mode) changed,
  74  * then drop it and recreate it.
  75  */
  76 static void
  77 cifs_prime_dcache(struct dentry *parent, struct qstr *name,
  78                     struct cifs_fattr *fattr)
  79 {
  80         struct dentry *dentry, *alias;
  81         struct inode *inode;
  82         struct super_block *sb = parent->d_sb;
  83         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
  84         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
  85
  86         cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
  87
  88         dentry = d_hash_and_lookup(parent, name);
  89         if (!dentry) {
  90                 /*
  91                  * If we know that the inode will need to be revalidated
  92                  * immediately, then don't create a new dentry for it.
  93                  * We'll end up doing an on the wire call either way and
  94                  * this spares us an invalidation.
  95                  */
  96                 if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
  97                         return;
  98 retry:
  99                 dentry = d_alloc_parallel(parent, name, &wq);
 100         }
 101         if (IS_ERR(dentry))
 102                 return;
 103         if (!d_in_lookup(dentry)) {
 104                 inode = d_inode(dentry);
 105                 if (inode) {
 106                         if (d_mountpoint(dentry)) {
 107                                 dput(dentry);
 108                                 return;
 109                         }
 110                         /*
 111                          * If we're generating inode numbers, then we don't
 112                          * want to clobber the existing one with the one that
 113                          * the readdir code created.
 114                          */
 115                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
 116                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
 117
 118                         /* update inode in place
 119                          * if both i_ino and i_mode didn't change */
 120                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid &&
 121                             (inode->i_mode & S_IFMT) ==
 122                             (fattr->cf_mode & S_IFMT)) {
 123                                 cifs_fattr_to_inode(inode, fattr);
 124                                 dput(dentry);
 125                                 return;
 126                         }
 127                 }
 128                 d_invalidate(dentry);
 129                 dput(dentry);
 130                 goto retry;
 131         } else {
 132                 inode = cifs_iget(sb, fattr);
 133                 if (!inode)
 134                         inode = ERR_PTR(-ENOMEM);
 135                 alias = d_splice_alias(inode, dentry);
 136                 d_lookup_done(dentry);
 137                 if (alias && !IS_ERR(alias))
 138                         dput(alias);
 139         }
 140         dput(dentry);
 141 }
 142
 143 static bool reparse_file_needs_reval(const struct cifs_fattr *fattr)
 144 {
 145         if (!(fattr->cf_cifsattrs & ATTR_REPARSE))
 146                 return false;
 147         /*
 148          * The DFS tags should be only intepreted by server side as per
 149          * MS-FSCC 2.1.2.1, but let's include them anyway.
 150          *
 151          * Besides, if cf_cifstag is unset (0), then we still need it to be
 152          * revalidated to know exactly what reparse point it is.
 153          */
 154         switch (fattr->cf_cifstag) {
 155         case IO_REPARSE_TAG_DFS:
 156         case IO_REPARSE_TAG_DFSR:
 157         case IO_REPARSE_TAG_SYMLINK:
 158         case IO_REPARSE_TAG_NFS:
 159         case 0:
 160                 return true;
 161         }
 162         return false;
 163 }
 164
 165 static void
 166 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 167 {
 168         fattr->cf_uid = cifs_sb->mnt_uid;
 169         fattr->cf_gid = cifs_sb->mnt_gid;
 170
 171         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 172                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 173                 fattr->cf_dtype = DT_DIR;
 174         } else {
 175                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 176                 fattr->cf_dtype = DT_REG;
 177         }
 178
 179         /*
 180          * We need to revalidate it further to make a decision about whether it
 181          * is a symbolic link, DFS referral or a reparse point with a direct
 182          * access like junctions, deduplicated files, NFS symlinks.
 183          */
 184         if (reparse_file_needs_reval(fattr))
 185                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 186
 187         /* non-unix readdir doesn't provide nlink */
 188         fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
 189
 190         if (fattr->cf_cifsattrs & ATTR_READONLY)
 191                 fattr->cf_mode &= ~S_IWUGO;
 192
 193         /*
 194          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 195          * mark it for revalidation so that "ls -l" will look right. It might
 196          * be super-slow, but if we don't do this then the ownership of files
 197          * may look wrong since the inodes may not have timed out by the time
 198          * "ls" does a stat() call on them.
 199          */
 200         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
 201             (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
 202                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 203
 204         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 205             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 206                 if (fattr->cf_eof == 0)  {
 207                         fattr->cf_mode &= ~S_IFMT;
 208                         fattr->cf_mode |= S_IFIFO;
 209                         fattr->cf_dtype = DT_FIFO;
 210                 } else {
 211                         /*
 212                          * trying to get the type and mode via SFU can be slow,
 213                          * so just call those regular files for now, and mark
 214                          * for reval
 215                          */
 216                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 217                 }
 218         }
 219 }
 220
 221 /* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
 222 static void
 223 cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
 224                     struct cifs_sb_info *cifs_sb)
 225 {
 226         struct smb2_posix_info_parsed parsed;
 227
 228         posix_info_parse(info, NULL, &parsed);
 229
 230         memset(fattr, 0, sizeof(*fattr));
 231         fattr->cf_uniqueid = le64_to_cpu(info->Inode);
 232         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 233         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 234
 235         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 236         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 237         fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
 238
 239         fattr->cf_nlink = le32_to_cpu(info->HardLinks);
 240         fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
 241
 242         /*
 243          * Since we set the inode type below we need to mask off
 244          * to avoid strange results if bits set above.
 245          * XXX: why not make server&client use the type bits?
 246          */
 247         fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
 248
 249         cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o",
 250                  le32_to_cpu(info->DeviceId),
 251                  le32_to_cpu(info->ReparseTag),
 252                  le32_to_cpu(info->Mode));
 253
 254         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 255                 fattr->cf_mode |= S_IFDIR;
 256                 fattr->cf_dtype = DT_DIR;
 257         } else {
 258                 /*
 259                  * mark anything that is not a dir as regular
 260                  * file. special files should have the REPARSE
 261                  * attribute and will be marked as needing revaluation
 262                  */
 263                 fattr->cf_mode |= S_IFREG;
 264                 fattr->cf_dtype = DT_REG;
 265         }
 266
 267         if (reparse_file_needs_reval(fattr))
 268                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 269
 270         /* TODO map SIDs */
 271         fattr->cf_uid = cifs_sb->mnt_uid;
 272         fattr->cf_gid = cifs_sb->mnt_gid;
 273 }
 274
 275 static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
 276 {
 277         const FILE_DIRECTORY_INFO *fi = info;
 278
 279         memset(fattr, 0, sizeof(*fattr));
 280         fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
 281         fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
 282         fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
 283         fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
 284         fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);
 285         fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);
 286         fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);
 287 }
 288
 289 void
 290 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 291                        struct cifs_sb_info *cifs_sb)
 292 {
 293         __dir_info_to_fattr(fattr, info);
 294         cifs_fill_common_info(fattr, cifs_sb);
 295 }
 296
 297 static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
 298                                        SEARCH_ID_FULL_DIR_INFO *info,
 299                                        struct cifs_sb_info *cifs_sb)
 300 {
 301         __dir_info_to_fattr(fattr, info);
 302
 303         /* See MS-FSCC 2.4.18 FileIdFullDirectoryInformation */
 304         if (fattr->cf_cifsattrs & ATTR_REPARSE)
 305                 fattr->cf_cifstag = le32_to_cpu(info->EaSize);
 306         cifs_fill_common_info(fattr, cifs_sb);
 307 }
 308
 309 static void
 310 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 311                        struct cifs_sb_info *cifs_sb)
 312 {
 313         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 314
 315         memset(fattr, 0, sizeof(*fattr));
 316         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 317                                             info->LastAccessTime, offset);
 318         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 319                                             info->LastWriteTime, offset);
 320         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 321                                             info->LastWriteTime, offset);
 322
 323         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 324         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 325         fattr->cf_eof = le32_to_cpu(info->DataSize);
 326
 327         cifs_fill_common_info(fattr, cifs_sb);
 328 }
 329
 330 /* BB eventually need to add the following helper function to
 331       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 332       we try to do FindFirst on (NTFS) directory symlinks */
 333 /*
 334 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 335                              unsigned int xid)
 336 {
 337         __u16 fid;
 338         int len;
 339         int oplock = 0;
 340         int rc;
 341         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 342         char *tmpbuffer;
 343
 344         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 345                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 346                         cifs_sb->local_nls,
 347                         cifs_remap(cifs_sb);
 348         if (!rc) {
 349                 tmpbuffer = kmalloc(maxpath);
 350                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 351                                 tmpbuffer,
 352                                 maxpath -1,
 353                                 fid,
 354                                 cifs_sb->local_nls);
 355                 if (CIFSSMBClose(xid, ptcon, fid)) {
 356                         cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
 357                 }
 358         }
 359 }
 360  */
 361
 362 static int
 363 initiate_cifs_search(const unsigned int xid, struct file *file)
 364 {
 365         __u16 search_flags;
 366         int rc = 0;
 367         char *full_path = NULL;
 368         struct cifsFileInfo *cifsFile;
 369         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 370         struct tcon_link *tlink = NULL;
 371         struct cifs_tcon *tcon;
 372         struct TCP_Server_Info *server;
 373
 374         if (file->private_data == NULL) {
 375                 tlink = cifs_sb_tlink(cifs_sb);
 376                 if (IS_ERR(tlink))
 377                         return PTR_ERR(tlink);
 378
 379                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 380                 if (cifsFile == NULL) {
 381                         rc = -ENOMEM;
 382                         goto error_exit;
 383                 }
 384                 spin_lock_init(&cifsFile->file_info_lock);
 385                 file->private_data = cifsFile;
 386                 cifsFile->tlink = cifs_get_tlink(tlink);
 387                 tcon = tlink_tcon(tlink);
 388         } else {
 389                 cifsFile = file->private_data;
 390                 tcon = tlink_tcon(cifsFile->tlink);
 391         }
 392
 393         server = tcon->ses->server;
 394
 395         if (!server->ops->query_dir_first) {
 396                 rc = -ENOSYS;
 397                 goto error_exit;
 398         }
 399
 400         cifsFile->invalidHandle = true;
 401         cifsFile->srch_inf.endOfSearch = false;
 402
 403         full_path = build_path_from_dentry(file_dentry(file));
 404         if (full_path == NULL) {
 405                 rc = -ENOMEM;
 406                 goto error_exit;
 407         }
 408
 409         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
 410
 411 ffirst_retry:
 412         /* test for Unix extensions */
 413         /* but now check for them on the share/mount not on the SMB session */
 414         /* if (cap_unix(tcon->ses) { */
 415         if (tcon->unix_ext)
 416                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 417         else if (tcon->posix_extensions)
 418                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
 419         else if ((tcon->ses->capabilities &
 420                   tcon->ses->server->vals->cap_nt_find) == 0) {
 421                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 422         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 423                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 424         } else /* not srvinos - BB fixme add check for backlevel? */ {
 425                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 426         }
 427
 428         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 429         if (backup_cred(cifs_sb))
 430                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 431
 432         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 433                                           &cifsFile->fid, search_flags,
 434                                           &cifsFile->srch_inf);
 435
 436         if (rc == 0)
 437                 cifsFile->invalidHandle = false;
 438         /* BB add following call to handle readdir on new NTFS symlink errors
 439         else if STATUS_STOPPED_ON_SYMLINK
 440                 call get_symlink_reparse_path and retry with new path */
 441         else if ((rc == -EOPNOTSUPP) &&
 442                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 443                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 444                 goto ffirst_retry;
 445         }
 446 error_exit:
 447         kfree(full_path);
 448         cifs_put_tlink(tlink);
 449         return rc;
 450 }
 451
 452 /* return length of unicode string in bytes */
 453 static int cifs_unicode_bytelen(const char *str)
 454 {
 455         int len;
 456         const __le16 *ustr = (const __le16 *)str;
 457
 458         for (len = 0; len <= PATH_MAX; len++) {
 459                 if (ustr[len] == 0)
 460                         return len << 1;
 461         }
 462         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
 463         return len << 1;
 464 }
 465
 466 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 467 {
 468         char *new_entry;
 469         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 470
 471         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 472                 FIND_FILE_STANDARD_INFO *pfData;
 473                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 474
 475                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 476                                 pfData->FileNameLength;
 477         } else {
 478                 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
 479
 480                 if (old_entry + next_offset < old_entry) {
 481                         cifs_dbg(VFS, "invalid offset %u\n", next_offset);
 482                         return NULL;
 483                 }
 484                 new_entry = old_entry + next_offset;
 485         }
 486         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
 487         /* validate that new_entry is not past end of SMB */
 488         if (new_entry >= end_of_smb) {
 489                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
 490                          new_entry, end_of_smb, old_entry);
 491                 return NULL;
 492         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 493                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 494                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 495                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 496                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
 497                          new_entry, end_of_smb);
 498                 return NULL;
 499         } else
 500                 return new_entry;
 501
 502 }
 503
 504 struct cifs_dirent {
 505         const char      *name;
 506         size_t          namelen;
 507         u32             resume_key;
 508         u64             ino;
 509 };
 510
 511 static void cifs_fill_dirent_posix(struct cifs_dirent *de,
 512                                    const struct smb2_posix_info *info)
 513 {
 514         struct smb2_posix_info_parsed parsed;
 515
 516         /* payload should have already been checked at this point */
 517         if (posix_info_parse(info, NULL, &parsed) < 0) {
 518                 cifs_dbg(VFS, "invalid POSIX info payload");
 519                 return;
 520         }
 521
 522         de->name = parsed.name;
 523         de->namelen = parsed.name_len;
 524         de->resume_key = info->Ignored;
 525         de->ino = le64_to_cpu(info->Inode);
 526 }
 527
 528 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 529                 const FILE_UNIX_INFO *info, bool is_unicode)
 530 {
 531         de->name = &info->FileName[0];
 532         if (is_unicode)
 533                 de->namelen = cifs_unicode_bytelen(de->name);
 534         else
 535                 de->namelen = strnlen(de->name, PATH_MAX);
 536         de->resume_key = info->ResumeKey;
 537         de->ino = le64_to_cpu(info->basic.UniqueId);
 538 }
 539
 540 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 541                 const FILE_DIRECTORY_INFO *info)
 542 {
 543         de->name = &info->FileName[0];
 544         de->namelen = le32_to_cpu(info->FileNameLength);
 545         de->resume_key = info->FileIndex;
 546 }
 547
 548 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 549                 const FILE_FULL_DIRECTORY_INFO *info)
 550 {
 551         de->name = &info->FileName[0];
 552         de->namelen = le32_to_cpu(info->FileNameLength);
 553         de->resume_key = info->FileIndex;
 554 }
 555
 556 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 557                 const SEARCH_ID_FULL_DIR_INFO *info)
 558 {
 559         de->name = &info->FileName[0];
 560         de->namelen = le32_to_cpu(info->FileNameLength);
 561         de->resume_key = info->FileIndex;
 562         de->ino = le64_to_cpu(info->UniqueId);
 563 }
 564
 565 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 566                 const FILE_BOTH_DIRECTORY_INFO *info)
 567 {
 568         de->name = &info->FileName[0];
 569         de->namelen = le32_to_cpu(info->FileNameLength);
 570         de->resume_key = info->FileIndex;
 571 }
 572
 573 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 574                 const FIND_FILE_STANDARD_INFO *info)
 575 {
 576         de->name = &info->FileName[0];
 577         /* one byte length, no endianess conversion */
 578         de->namelen = info->FileNameLength;
 579         de->resume_key = info->ResumeKey;
 580 }
 581
 582 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 583                 u16 level, bool is_unicode)
 584 {
 585         memset(de, 0, sizeof(*de));
 586
 587         switch (level) {
 588         case SMB_FIND_FILE_POSIX_INFO:
 589                 cifs_fill_dirent_posix(de, info);
 590                 break;
 591         case SMB_FIND_FILE_UNIX:
 592                 cifs_fill_dirent_unix(de, info, is_unicode);
 593                 break;
 594         case SMB_FIND_FILE_DIRECTORY_INFO:
 595                 cifs_fill_dirent_dir(de, info);
 596                 break;
 597         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 598                 cifs_fill_dirent_full(de, info);
 599                 break;
 600         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 601                 cifs_fill_dirent_search(de, info);
 602                 break;
 603         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 604                 cifs_fill_dirent_both(de, info);
 605                 break;
 606         case SMB_FIND_FILE_INFO_STANDARD:
 607                 cifs_fill_dirent_std(de, info);
 608                 break;
 609         default:
 610                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
 611                 return -EINVAL;
 612         }
 613
 614         return 0;
 615 }
 616
 617 #define UNICODE_DOT cpu_to_le16(0x2e)
 618
 619 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 620 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 621 {
 622         int rc = 0;
 623
 624         if (!de->name)
 625                 return 0;
 626
 627         if (is_unicode) {
 628                 __le16 *ufilename = (__le16 *)de->name;
 629                 if (de->namelen == 2) {
 630                         /* check for . */
 631                         if (ufilename[0] == UNICODE_DOT)
 632                                 rc = 1;
 633                 } else if (de->namelen == 4) {
 634                         /* check for .. */
 635                         if (ufilename[0] == UNICODE_DOT &&
 636                             ufilename[1] == UNICODE_DOT)
 637                                 rc = 2;
 638                 }
 639         } else /* ASCII */ {
 640                 if (de->namelen == 1) {
 641                         if (de->name[0] == '.')
 642                                 rc = 1;
 643                 } else if (de->namelen == 2) {
 644                         if (de->name[0] == '.' && de->name[1] == '.')
 645                                 rc = 2;
 646                 }
 647         }
 648
 649         return rc;
 650 }
 651
 652 /* Check if directory that we are searching has changed so we can decide
 653    whether we can use the cached search results from the previous search */
 654 static int is_dir_changed(struct file *file)
 655 {
 656         struct inode *inode = file_inode(file);
 657         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 658
 659         if (cifsInfo->time == 0)
 660                 return 1; /* directory was changed, perhaps due to unlink */
 661         else
 662                 return 0;
 663
 664 }
 665
 666 static int cifs_save_resume_key(const char *current_entry,
 667         struct cifsFileInfo *file_info)
 668 {
 669         struct cifs_dirent de;
 670         int rc;
 671
 672         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 673                               file_info->srch_inf.unicode);
 674         if (!rc) {
 675                 file_info->srch_inf.presume_name = de.name;
 676                 file_info->srch_inf.resume_name_len = de.namelen;
 677                 file_info->srch_inf.resume_key = de.resume_key;
 678         }
 679         return rc;
 680 }
 681
 682 /*
 683  * Find the corresponding entry in the search. Note that the SMB server returns
 684  * search entries for . and .. which complicates logic here if we choose to
 685  * parse for them and we do not assume that they are located in the findfirst
 686  * return buffer. We start counting in the buffer with entry 2 and increment for
 687  * every entry (do not increment for . or .. entry).
 688  */
 689 static int
 690 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
 691                 struct file *file, char **current_entry, int *num_to_ret)
 692 {
 693         __u16 search_flags;
 694         int rc = 0;
 695         int pos_in_buf = 0;
 696         loff_t first_entry_in_buffer;
 697         loff_t index_to_find = pos;
 698         struct cifsFileInfo *cfile = file->private_data;
 699         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 700         struct TCP_Server_Info *server = tcon->ses->server;
 701         /* check if index in the buffer */
 702
 703         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 704                 return -ENOSYS;
 705
 706         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 707                 return -ENOENT;
 708
 709         *current_entry = NULL;
 710         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 711                                         cfile->srch_inf.entries_in_buffer;
 712
 713         /*
 714          * If first entry in buf is zero then is first buffer
 715          * in search response data which means it is likely . and ..
 716          * will be in this buffer, although some servers do not return
 717          * . and .. for the root of a drive and for those we need
 718          * to start two entries earlier.
 719          */
 720
 721         dump_cifs_file_struct(file, "In fce ");
 722         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 723              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 724                 /* close and restart search */
 725                 cifs_dbg(FYI, "search backing up - close and restart search\n");
 726                 spin_lock(&cfile->file_info_lock);
 727                 if (server->ops->dir_needs_close(cfile)) {
 728                         cfile->invalidHandle = true;
 729                         spin_unlock(&cfile->file_info_lock);
 730                         if (server->ops->close_dir)
 731                                 server->ops->close_dir(xid, tcon, &cfile->fid);
 732                 } else
 733                         spin_unlock(&cfile->file_info_lock);
 734                 if (cfile->srch_inf.ntwrk_buf_start) {
 735                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
 736                         if (cfile->srch_inf.smallBuf)
 737                                 cifs_small_buf_release(cfile->srch_inf.
 738                                                 ntwrk_buf_start);
 739                         else
 740                                 cifs_buf_release(cfile->srch_inf.
 741                                                 ntwrk_buf_start);
 742                         cfile->srch_inf.ntwrk_buf_start = NULL;
 743                 }
 744                 rc = initiate_cifs_search(xid, file);
 745                 if (rc) {
 746                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
 747                                  rc);
 748                         return rc;
 749                 }
 750                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 751                 if (cfile->srch_inf.last_entry)
 752                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 753         }
 754
 755         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 756         if (backup_cred(cifs_sb))
 757                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 758
 759         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 760                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 761                 cifs_dbg(FYI, "calling findnext2\n");
 762                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 763                                                  search_flags,
 764                                                  &cfile->srch_inf);
 765                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 766                 if (cfile->srch_inf.last_entry)
 767                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 768                 if (rc)
 769                         return -ENOENT;
 770         }
 771         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 772                 /* we found the buffer that contains the entry */
 773                 /* scan and find it */
 774                 int i;
 775                 char *cur_ent;
 776                 char *end_of_smb;
 777
 778                 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
 779                         cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
 780                         return -EIO;
 781                 }
 782
 783                 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 784                         server->ops->calc_smb_size(
 785                                         cfile->srch_inf.ntwrk_buf_start,
 786                                         server);
 787
 788                 cur_ent = cfile->srch_inf.srch_entries_start;
 789                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 790                                         - cfile->srch_inf.entries_in_buffer;
 791                 pos_in_buf = index_to_find - first_entry_in_buffer;
 792                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
 793
 794                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 795                         /* go entry by entry figuring out which is first */
 796                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 797                                                 cfile->srch_inf.info_level);
 798                 }
 799                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 800                         /* BB fixme - check if we should flag this error */
 801                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
 802                                  pos_in_buf, index_to_find, rc);
 803                 }
 804                 rc = 0;
 805                 *current_entry = cur_ent;
 806         } else {
 807                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
 808                 return 0;
 809         }
 810
 811         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 812                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
 813                 *num_to_ret = 0;
 814         } else
 815                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 816
 817         return rc;
 818 }
 819
 820 static int cifs_filldir(char *find_entry, struct file *file,
 821                 struct dir_context *ctx,
 822                 char *scratch_buf, unsigned int max_len)
 823 {
 824         struct cifsFileInfo *file_info = file->private_data;
 825         struct super_block *sb = file_inode(file)->i_sb;
 826         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 827         struct cifs_dirent de = { NULL, };
 828         struct cifs_fattr fattr;
 829         struct qstr name;
 830         int rc = 0;
 831         ino_t ino;
 832
 833         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 834                               file_info->srch_inf.unicode);
 835         if (rc)
 836                 return rc;
 837
 838         if (de.namelen > max_len) {
 839                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
 840                          de.namelen);
 841                 return -EINVAL;
 842         }
 843
 844         /* skip . and .. since we added them first */
 845         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 846                 return 0;
 847
 848         if (file_info->srch_inf.unicode) {
 849                 struct nls_table *nlt = cifs_sb->local_nls;
 850                 int map_type;
 851
 852                 map_type = cifs_remap(cifs_sb);
 853                 name.name = scratch_buf;
 854                 name.len =
 855                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 856                                         UNICODE_NAME_MAX,
 857                                         min_t(size_t, de.namelen,
 858                                               (size_t)max_len), nlt, map_type);
 859                 name.len -= nls_nullsize(nlt);
 860         } else {
 861                 name.name = de.name;
 862                 name.len = de.namelen;
 863         }
 864
 865         switch (file_info->srch_inf.info_level) {
 866         case SMB_FIND_FILE_POSIX_INFO:
 867                 cifs_posix_to_fattr(&fattr,
 868                                     (struct smb2_posix_info *)find_entry,
 869                                     cifs_sb);
 870                 break;
 871         case SMB_FIND_FILE_UNIX:
 872                 cifs_unix_basic_to_fattr(&fattr,
 873                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 874                                          cifs_sb);
 875                 break;
 876         case SMB_FIND_FILE_INFO_STANDARD:
 877                 cifs_std_info_to_fattr(&fattr,
 878                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 879                                        cifs_sb);
 880                 break;
 881         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 882                 cifs_fulldir_info_to_fattr(&fattr,
 883                                            (SEARCH_ID_FULL_DIR_INFO *)find_entry,
 884                                            cifs_sb);
 885                 break;
 886         default:
 887                 cifs_dir_info_to_fattr(&fattr,
 888                                        (FILE_DIRECTORY_INFO *)find_entry,
 889                                        cifs_sb);
 890                 break;
 891         }
 892
 893         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 894                 fattr.cf_uniqueid = de.ino;
 895         } else {
 896                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 897                 cifs_autodisable_serverino(cifs_sb);
 898         }
 899
 900         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 901             couldbe_mf_symlink(&fattr))
 902                 /*
 903                  * trying to get the type and mode can be slow,
 904                  * so just call those regular files for now, and mark
 905                  * for reval
 906                  */
 907                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 908
 909         cifs_prime_dcache(file_dentry(file), &name, &fattr);
 910
 911         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 912         return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
 913 }
 914
 915
 916 int cifs_readdir(struct file *file, struct dir_context *ctx)
 917 {
 918         int rc = 0;
 919         unsigned int xid;
 920         int i;
 921         struct cifs_tcon *tcon;
 922         struct cifsFileInfo *cifsFile = NULL;
 923         char *current_entry;
 924         int num_to_fill = 0;
 925         char *tmp_buf = NULL;
 926         char *end_of_smb;
 927         unsigned int max_len;
 928
 929         xid = get_xid();
 930
 931         /*
 932          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 933          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 934          */
 935         if (file->private_data == NULL) {
 936                 rc = initiate_cifs_search(xid, file);
 937                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
 938                 if (rc)
 939                         goto rddir2_exit;
 940         }
 941
 942         if (!dir_emit_dots(file, ctx))
 943                 goto rddir2_exit;
 944
 945         /* 1) If search is active,
 946                 is in current search buffer?
 947                 if it before then restart search
 948                 if after then keep searching till find it */
 949
 950         cifsFile = file->private_data;
 951         if (cifsFile->srch_inf.endOfSearch) {
 952                 if (cifsFile->srch_inf.emptyDir) {
 953                         cifs_dbg(FYI, "End of search, empty dir\n");
 954                         rc = 0;
 955                         goto rddir2_exit;
 956                 }
 957         } /* else {
 958                 cifsFile->invalidHandle = true;
 959                 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
 960         } */
 961
 962         tcon = tlink_tcon(cifsFile->tlink);
 963         rc = find_cifs_entry(xid, tcon, ctx->pos, file, &current_entry,
 964                              &num_to_fill);
 965         if (rc) {
 966                 cifs_dbg(FYI, "fce error %d\n", rc);
 967                 goto rddir2_exit;
 968         } else if (current_entry != NULL) {
 969                 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
 970         } else {
 971                 cifs_dbg(FYI, "could not find entry\n");
 972                 goto rddir2_exit;
 973         }
 974         cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
 975                  num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 976         max_len = tcon->ses->server->ops->calc_smb_size(
 977                         cifsFile->srch_inf.ntwrk_buf_start,
 978                         tcon->ses->server);
 979         end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 980
 981         tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 982         if (tmp_buf == NULL) {
 983                 rc = -ENOMEM;
 984                 goto rddir2_exit;
 985         }
 986
 987         for (i = 0; i < num_to_fill; i++) {
 988                 if (current_entry == NULL) {
 989                         /* evaluate whether this case is an error */
 990                         cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
 991                                  num_to_fill, i);
 992                         break;
 993                 }
 994                 /*
 995                  * if buggy server returns . and .. late do we want to
 996                  * check for that here?
 997                  */
 998                 *tmp_buf = 0;
 999                 rc = cifs_filldir(current_entry, file, ctx,
1000                                   tmp_buf, max_len);
1001                 if (rc) {
1002                         if (rc > 0)
1003                                 rc = 0;
1004                         break;
1005                 }
1006
1007                 ctx->pos++;
1008                 if (ctx->pos ==
1009                         cifsFile->srch_inf.index_of_last_entry) {
1010                         cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
1011                                  ctx->pos, tmp_buf);
1012                         cifs_save_resume_key(current_entry, cifsFile);
1013                         break;
1014                 } else
1015                         current_entry =
1016                                 nxt_dir_entry(current_entry, end_of_smb,
1017                                         cifsFile->srch_inf.info_level);
1018         }
1019         kfree(tmp_buf);
1020
1021 rddir2_exit:
1022         free_xid(xid);
1023         return rc;
1024 }