fs/cifs/readdir.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   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  */
  11 #include <linux/fs.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/slab.h>
  14 #include <linux/stat.h>
  15 #include "cifspdu.h"
  16 #include "cifsglob.h"
  17 #include "cifsproto.h"
  18 #include "cifs_unicode.h"
  19 #include "cifs_debug.h"
  20 #include "cifs_fs_sb.h"
  21 #include "cifsfs.h"
  22 #include "smb2proto.h"
  23 #include "fs_context.h"
  24
  25 /*
  26  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  27  * characters alloc more to account for such multibyte target UTF-8
  28  * characters.
  29  */
  30 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  31
  32 #ifdef CONFIG_CIFS_DEBUG2
  33 static void dump_cifs_file_struct(struct file *file, char *label)
  34 {
  35         struct cifsFileInfo *cf;
  36
  37         if (file) {
  38                 cf = file->private_data;
  39                 if (cf == NULL) {
  40                         cifs_dbg(FYI, "empty cifs private file data\n");
  41                         return;
  42                 }
  43                 if (cf->invalidHandle)
  44                         cifs_dbg(FYI, "Invalid handle\n");
  45                 if (cf->srch_inf.endOfSearch)
  46                         cifs_dbg(FYI, "end of search\n");
  47                 if (cf->srch_inf.emptyDir)
  48                         cifs_dbg(FYI, "empty dir\n");
  49         }
  50 }
  51 #else
  52 static inline void dump_cifs_file_struct(struct file *file, char *label)
  53 {
  54 }
  55 #endif /* DEBUG2 */
  56
  57 /*
  58  * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
  59  *
  60  * Find the dentry that matches "name". If there isn't one, create one. If it's
  61  * a negative dentry or the uniqueid or filetype(mode) changed,
  62  * then drop it and recreate it.
  63  */
  64 static void
  65 cifs_prime_dcache(struct dentry *parent, struct qstr *name,
  66                     struct cifs_fattr *fattr)
  67 {
  68         struct dentry *dentry, *alias;
  69         struct inode *inode;
  70         struct super_block *sb = parent->d_sb;
  71         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
  72         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
  73
  74         cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
  75
  76         dentry = d_hash_and_lookup(parent, name);
  77         if (!dentry) {
  78                 /*
  79                  * If we know that the inode will need to be revalidated
  80                  * immediately, then don't create a new dentry for it.
  81                  * We'll end up doing an on the wire call either way and
  82                  * this spares us an invalidation.
  83                  */
  84                 if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
  85                         return;
  86 retry:
  87                 dentry = d_alloc_parallel(parent, name, &wq);
  88         }
  89         if (IS_ERR(dentry))
  90                 return;
  91         if (!d_in_lookup(dentry)) {
  92                 inode = d_inode(dentry);
  93                 if (inode) {
  94                         if (d_mountpoint(dentry)) {
  95                                 dput(dentry);
  96                                 return;
  97                         }
  98                         /*
  99                          * If we're generating inode numbers, then we don't
 100                          * want to clobber the existing one with the one that
 101                          * the readdir code created.
 102                          */
 103                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
 104                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
 105
 106                         /* update inode in place
 107                          * if both i_ino and i_mode didn't change */
 108                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid &&
 109                             cifs_fattr_to_inode(inode, fattr) == 0) {
 110                                 dput(dentry);
 111                                 return;
 112                         }
 113                 }
 114                 d_invalidate(dentry);
 115                 dput(dentry);
 116                 goto retry;
 117         } else {
 118                 inode = cifs_iget(sb, fattr);
 119                 if (!inode)
 120                         inode = ERR_PTR(-ENOMEM);
 121                 alias = d_splice_alias(inode, dentry);
 122                 d_lookup_done(dentry);
 123                 if (alias && !IS_ERR(alias))
 124                         dput(alias);
 125         }
 126         dput(dentry);
 127 }
 128
 129 static bool reparse_file_needs_reval(const struct cifs_fattr *fattr)
 130 {
 131         if (!(fattr->cf_cifsattrs & ATTR_REPARSE))
 132                 return false;
 133         /*
 134          * The DFS tags should be only intepreted by server side as per
 135          * MS-FSCC 2.1.2.1, but let's include them anyway.
 136          *
 137          * Besides, if cf_cifstag is unset (0), then we still need it to be
 138          * revalidated to know exactly what reparse point it is.
 139          */
 140         switch (fattr->cf_cifstag) {
 141         case IO_REPARSE_TAG_DFS:
 142         case IO_REPARSE_TAG_DFSR:
 143         case IO_REPARSE_TAG_SYMLINK:
 144         case IO_REPARSE_TAG_NFS:
 145         case 0:
 146                 return true;
 147         }
 148         return false;
 149 }
 150
 151 static void
 152 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 153 {
 154         fattr->cf_uid = cifs_sb->ctx->linux_uid;
 155         fattr->cf_gid = cifs_sb->ctx->linux_gid;
 156
 157         /*
 158          * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they
 159          * are preferred by the Linux client in some cases since, unlike
 160          * the NFS reparse tag (or EAs), they don't require an extra query
 161          * to determine which type of special file they represent.
 162          * TODO: go through all documented  reparse tags to see if we can
 163          * reasonably map some of them to directories vs. files vs. symlinks
 164          */
 165         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 166                 fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode;
 167                 fattr->cf_dtype = DT_DIR;
 168         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_SYMLINK) {
 169                 fattr->cf_mode |= S_IFLNK | cifs_sb->ctx->file_mode;
 170                 fattr->cf_dtype = DT_LNK;
 171         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_FIFO) {
 172                 fattr->cf_mode |= S_IFIFO | cifs_sb->ctx->file_mode;
 173                 fattr->cf_dtype = DT_FIFO;
 174         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_AF_UNIX) {
 175                 fattr->cf_mode |= S_IFSOCK | cifs_sb->ctx->file_mode;
 176                 fattr->cf_dtype = DT_SOCK;
 177         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_CHR) {
 178                 fattr->cf_mode |= S_IFCHR | cifs_sb->ctx->file_mode;
 179                 fattr->cf_dtype = DT_CHR;
 180         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_BLK) {
 181                 fattr->cf_mode |= S_IFBLK | cifs_sb->ctx->file_mode;
 182                 fattr->cf_dtype = DT_BLK;
 183         } else { /* TODO: should we mark some other reparse points (like DFSR) as directories? */
 184                 fattr->cf_mode = S_IFREG | cifs_sb->ctx->file_mode;
 185                 fattr->cf_dtype = DT_REG;
 186         }
 187
 188         /*
 189          * We need to revalidate it further to make a decision about whether it
 190          * is a symbolic link, DFS referral or a reparse point with a direct
 191          * access like junctions, deduplicated files, NFS symlinks.
 192          */
 193         if (reparse_file_needs_reval(fattr))
 194                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 195
 196         /* non-unix readdir doesn't provide nlink */
 197         fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
 198
 199         if (fattr->cf_cifsattrs & ATTR_READONLY)
 200                 fattr->cf_mode &= ~S_IWUGO;
 201
 202         /*
 203          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 204          * mark it for revalidation so that "ls -l" will look right. It might
 205          * be super-slow, but if we don't do this then the ownership of files
 206          * may look wrong since the inodes may not have timed out by the time
 207          * "ls" does a stat() call on them.
 208          */
 209         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
 210             (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
 211                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 212
 213         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 214             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 215                 if (fattr->cf_eof == 0)  {
 216                         fattr->cf_mode &= ~S_IFMT;
 217                         fattr->cf_mode |= S_IFIFO;
 218                         fattr->cf_dtype = DT_FIFO;
 219                 } else {
 220                         /*
 221                          * trying to get the type and mode via SFU can be slow,
 222                          * so just call those regular files for now, and mark
 223                          * for reval
 224                          */
 225                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 226                 }
 227         }
 228 }
 229
 230 /* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
 231 static void
 232 cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
 233                     struct cifs_sb_info *cifs_sb)
 234 {
 235         struct smb2_posix_info_parsed parsed;
 236
 237         posix_info_parse(info, NULL, &parsed);
 238
 239         memset(fattr, 0, sizeof(*fattr));
 240         fattr->cf_uniqueid = le64_to_cpu(info->Inode);
 241         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 242         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 243
 244         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 245         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 246         fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
 247
 248         fattr->cf_nlink = le32_to_cpu(info->HardLinks);
 249         fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
 250
 251         /*
 252          * Since we set the inode type below we need to mask off
 253          * to avoid strange results if bits set above.
 254          * XXX: why not make server&client use the type bits?
 255          */
 256         fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
 257
 258         cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
 259                  le32_to_cpu(info->DeviceId),
 260                  le32_to_cpu(info->ReparseTag),
 261                  le32_to_cpu(info->Mode));
 262
 263         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 264                 fattr->cf_mode |= S_IFDIR;
 265                 fattr->cf_dtype = DT_DIR;
 266         } else {
 267                 /*
 268                  * mark anything that is not a dir as regular
 269                  * file. special files should have the REPARSE
 270                  * attribute and will be marked as needing revaluation
 271                  */
 272                 fattr->cf_mode |= S_IFREG;
 273                 fattr->cf_dtype = DT_REG;
 274         }
 275
 276         if (reparse_file_needs_reval(fattr))
 277                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 278
 279         sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER);
 280         sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP);
 281 }
 282
 283 static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
 284 {
 285         const FILE_DIRECTORY_INFO *fi = info;
 286
 287         memset(fattr, 0, sizeof(*fattr));
 288         fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
 289         fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
 290         fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
 291         fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
 292         fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);
 293         fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);
 294         fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);
 295 }
 296
 297 void
 298 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 299                        struct cifs_sb_info *cifs_sb)
 300 {
 301         __dir_info_to_fattr(fattr, info);
 302         cifs_fill_common_info(fattr, cifs_sb);
 303 }
 304
 305 static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
 306                                        SEARCH_ID_FULL_DIR_INFO *info,
 307                                        struct cifs_sb_info *cifs_sb)
 308 {
 309         __dir_info_to_fattr(fattr, info);
 310
 311         /* See MS-FSCC 2.4.19 FileIdFullDirectoryInformation */
 312         if (fattr->cf_cifsattrs & ATTR_REPARSE)
 313                 fattr->cf_cifstag = le32_to_cpu(info->EaSize);
 314         cifs_fill_common_info(fattr, cifs_sb);
 315 }
 316
 317 static void
 318 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 319                        struct cifs_sb_info *cifs_sb)
 320 {
 321         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 322
 323         memset(fattr, 0, sizeof(*fattr));
 324         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 325                                             info->LastAccessTime, offset);
 326         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 327                                             info->LastWriteTime, offset);
 328         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 329                                             info->LastWriteTime, offset);
 330
 331         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 332         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 333         fattr->cf_eof = le32_to_cpu(info->DataSize);
 334
 335         cifs_fill_common_info(fattr, cifs_sb);
 336 }
 337
 338 /* BB eventually need to add the following helper function to
 339       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 340       we try to do FindFirst on (NTFS) directory symlinks */
 341 /*
 342 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 343                              unsigned int xid)
 344 {
 345         __u16 fid;
 346         int len;
 347         int oplock = 0;
 348         int rc;
 349         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 350         char *tmpbuffer;
 351
 352         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 353                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 354                         cifs_sb->local_nls,
 355                         cifs_remap(cifs_sb);
 356         if (!rc) {
 357                 tmpbuffer = kmalloc(maxpath);
 358                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 359                                 tmpbuffer,
 360                                 maxpath -1,
 361                                 fid,
 362                                 cifs_sb->local_nls);
 363                 if (CIFSSMBClose(xid, ptcon, fid)) {
 364                         cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
 365                 }
 366         }
 367 }
 368  */
 369
 370 static int
 371 _initiate_cifs_search(const unsigned int xid, struct file *file,
 372                      const char *full_path)
 373 {
 374         __u16 search_flags;
 375         int rc = 0;
 376         struct cifsFileInfo *cifsFile;
 377         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 378         struct tcon_link *tlink = NULL;
 379         struct cifs_tcon *tcon;
 380         struct TCP_Server_Info *server;
 381
 382         if (file->private_data == NULL) {
 383                 tlink = cifs_sb_tlink(cifs_sb);
 384                 if (IS_ERR(tlink))
 385                         return PTR_ERR(tlink);
 386
 387                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 388                 if (cifsFile == NULL) {
 389                         rc = -ENOMEM;
 390                         goto error_exit;
 391                 }
 392                 spin_lock_init(&cifsFile->file_info_lock);
 393                 file->private_data = cifsFile;
 394                 cifsFile->tlink = cifs_get_tlink(tlink);
 395                 tcon = tlink_tcon(tlink);
 396         } else {
 397                 cifsFile = file->private_data;
 398                 tcon = tlink_tcon(cifsFile->tlink);
 399         }
 400
 401         server = tcon->ses->server;
 402
 403         if (!server->ops->query_dir_first) {
 404                 rc = -ENOSYS;
 405                 goto error_exit;
 406         }
 407
 408         cifsFile->invalidHandle = true;
 409         cifsFile->srch_inf.endOfSearch = false;
 410
 411         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
 412
 413 ffirst_retry:
 414         /* test for Unix extensions */
 415         /* but now check for them on the share/mount not on the SMB session */
 416         /* if (cap_unix(tcon->ses) { */
 417         if (tcon->unix_ext)
 418                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 419         else if (tcon->posix_extensions)
 420                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
 421         else if ((tcon->ses->capabilities &
 422                   tcon->ses->server->vals->cap_nt_find) == 0) {
 423                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 424         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 425                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 426         } else /* not srvinos - BB fixme add check for backlevel? */ {
 427                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 428         }
 429
 430         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 431         if (backup_cred(cifs_sb))
 432                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 433
 434         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 435                                           &cifsFile->fid, search_flags,
 436                                           &cifsFile->srch_inf);
 437
 438         if (rc == 0)
 439                 cifsFile->invalidHandle = false;
 440         /* BB add following call to handle readdir on new NTFS symlink errors
 441         else if STATUS_STOPPED_ON_SYMLINK
 442                 call get_symlink_reparse_path and retry with new path */
 443         else if ((rc == -EOPNOTSUPP) &&
 444                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 445                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 446                 goto ffirst_retry;
 447         }
 448 error_exit:
 449         cifs_put_tlink(tlink);
 450         return rc;
 451 }
 452
 453 static int
 454 initiate_cifs_search(const unsigned int xid, struct file *file,
 455                      const char *full_path)
 456 {
 457         int rc, retry_count = 0;
 458
 459         do {
 460                 rc = _initiate_cifs_search(xid, file, full_path);
 461                 /*
 462                  * If we don't have enough credits to start reading the
 463                  * directory just try again after short wait.
 464                  */
 465                 if (rc != -EDEADLK)
 466                         break;
 467
 468                 usleep_range(512, 2048);
 469         } while (retry_count++ < 5);
 470
 471         return rc;
 472 }
 473
 474 /* return length of unicode string in bytes */
 475 static int cifs_unicode_bytelen(const char *str)
 476 {
 477         int len;
 478         const __le16 *ustr = (const __le16 *)str;
 479
 480         for (len = 0; len <= PATH_MAX; len++) {
 481                 if (ustr[len] == 0)
 482                         return len << 1;
 483         }
 484         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
 485         return len << 1;
 486 }
 487
 488 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 489 {
 490         char *new_entry;
 491         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 492
 493         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 494                 FIND_FILE_STANDARD_INFO *pfData;
 495                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 496
 497                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 498                                 pfData->FileNameLength;
 499         } else {
 500                 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
 501
 502                 if (old_entry + next_offset < old_entry) {
 503                         cifs_dbg(VFS, "Invalid offset %u\n", next_offset);
 504                         return NULL;
 505                 }
 506                 new_entry = old_entry + next_offset;
 507         }
 508         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
 509         /* validate that new_entry is not past end of SMB */
 510         if (new_entry >= end_of_smb) {
 511                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
 512                          new_entry, end_of_smb, old_entry);
 513                 return NULL;
 514         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 515                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 516                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 517                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 518                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
 519                          new_entry, end_of_smb);
 520                 return NULL;
 521         } else
 522                 return new_entry;
 523
 524 }
 525
 526 struct cifs_dirent {
 527         const char      *name;
 528         size_t          namelen;
 529         u32             resume_key;
 530         u64             ino;
 531 };
 532
 533 static void cifs_fill_dirent_posix(struct cifs_dirent *de,
 534                                    const struct smb2_posix_info *info)
 535 {
 536         struct smb2_posix_info_parsed parsed;
 537
 538         /* payload should have already been checked at this point */
 539         if (posix_info_parse(info, NULL, &parsed) < 0) {
 540                 cifs_dbg(VFS, "Invalid POSIX info payload\n");
 541                 return;
 542         }
 543
 544         de->name = parsed.name;
 545         de->namelen = parsed.name_len;
 546         de->resume_key = info->Ignored;
 547         de->ino = le64_to_cpu(info->Inode);
 548 }
 549
 550 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 551                 const FILE_UNIX_INFO *info, bool is_unicode)
 552 {
 553         de->name = &info->FileName[0];
 554         if (is_unicode)
 555                 de->namelen = cifs_unicode_bytelen(de->name);
 556         else
 557                 de->namelen = strnlen(de->name, PATH_MAX);
 558         de->resume_key = info->ResumeKey;
 559         de->ino = le64_to_cpu(info->basic.UniqueId);
 560 }
 561
 562 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 563                 const FILE_DIRECTORY_INFO *info)
 564 {
 565         de->name = &info->FileName[0];
 566         de->namelen = le32_to_cpu(info->FileNameLength);
 567         de->resume_key = info->FileIndex;
 568 }
 569
 570 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 571                 const FILE_FULL_DIRECTORY_INFO *info)
 572 {
 573         de->name = &info->FileName[0];
 574         de->namelen = le32_to_cpu(info->FileNameLength);
 575         de->resume_key = info->FileIndex;
 576 }
 577
 578 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 579                 const SEARCH_ID_FULL_DIR_INFO *info)
 580 {
 581         de->name = &info->FileName[0];
 582         de->namelen = le32_to_cpu(info->FileNameLength);
 583         de->resume_key = info->FileIndex;
 584         de->ino = le64_to_cpu(info->UniqueId);
 585 }
 586
 587 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 588                 const FILE_BOTH_DIRECTORY_INFO *info)
 589 {
 590         de->name = &info->FileName[0];
 591         de->namelen = le32_to_cpu(info->FileNameLength);
 592         de->resume_key = info->FileIndex;
 593 }
 594
 595 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 596                 const FIND_FILE_STANDARD_INFO *info)
 597 {
 598         de->name = &info->FileName[0];
 599         /* one byte length, no endianess conversion */
 600         de->namelen = info->FileNameLength;
 601         de->resume_key = info->ResumeKey;
 602 }
 603
 604 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 605                 u16 level, bool is_unicode)
 606 {
 607         memset(de, 0, sizeof(*de));
 608
 609         switch (level) {
 610         case SMB_FIND_FILE_POSIX_INFO:
 611                 cifs_fill_dirent_posix(de, info);
 612                 break;
 613         case SMB_FIND_FILE_UNIX:
 614                 cifs_fill_dirent_unix(de, info, is_unicode);
 615                 break;
 616         case SMB_FIND_FILE_DIRECTORY_INFO:
 617                 cifs_fill_dirent_dir(de, info);
 618                 break;
 619         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 620                 cifs_fill_dirent_full(de, info);
 621                 break;
 622         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 623                 cifs_fill_dirent_search(de, info);
 624                 break;
 625         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 626                 cifs_fill_dirent_both(de, info);
 627                 break;
 628         case SMB_FIND_FILE_INFO_STANDARD:
 629                 cifs_fill_dirent_std(de, info);
 630                 break;
 631         default:
 632                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
 633                 return -EINVAL;
 634         }
 635
 636         return 0;
 637 }
 638
 639 #define UNICODE_DOT cpu_to_le16(0x2e)
 640
 641 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 642 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 643 {
 644         int rc = 0;
 645
 646         if (!de->name)
 647                 return 0;
 648
 649         if (is_unicode) {
 650                 __le16 *ufilename = (__le16 *)de->name;
 651                 if (de->namelen == 2) {
 652                         /* check for . */
 653                         if (ufilename[0] == UNICODE_DOT)
 654                                 rc = 1;
 655                 } else if (de->namelen == 4) {
 656                         /* check for .. */
 657                         if (ufilename[0] == UNICODE_DOT &&
 658                             ufilename[1] == UNICODE_DOT)
 659                                 rc = 2;
 660                 }
 661         } else /* ASCII */ {
 662                 if (de->namelen == 1) {
 663                         if (de->name[0] == '.')
 664                                 rc = 1;
 665                 } else if (de->namelen == 2) {
 666                         if (de->name[0] == '.' && de->name[1] == '.')
 667                                 rc = 2;
 668                 }
 669         }
 670
 671         return rc;
 672 }
 673
 674 /* Check if directory that we are searching has changed so we can decide
 675    whether we can use the cached search results from the previous search */
 676 static int is_dir_changed(struct file *file)
 677 {
 678         struct inode *inode = file_inode(file);
 679         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 680
 681         if (cifsInfo->time == 0)
 682                 return 1; /* directory was changed, perhaps due to unlink */
 683         else
 684                 return 0;
 685
 686 }
 687
 688 static int cifs_save_resume_key(const char *current_entry,
 689         struct cifsFileInfo *file_info)
 690 {
 691         struct cifs_dirent de;
 692         int rc;
 693
 694         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 695                               file_info->srch_inf.unicode);
 696         if (!rc) {
 697                 file_info->srch_inf.presume_name = de.name;
 698                 file_info->srch_inf.resume_name_len = de.namelen;
 699                 file_info->srch_inf.resume_key = de.resume_key;
 700         }
 701         return rc;
 702 }
 703
 704 /*
 705  * Find the corresponding entry in the search. Note that the SMB server returns
 706  * search entries for . and .. which complicates logic here if we choose to
 707  * parse for them and we do not assume that they are located in the findfirst
 708  * return buffer. We start counting in the buffer with entry 2 and increment for
 709  * every entry (do not increment for . or .. entry).
 710  */
 711 static int
 712 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
 713                 struct file *file, const char *full_path,
 714                 char **current_entry, int *num_to_ret)
 715 {
 716         __u16 search_flags;
 717         int rc = 0;
 718         int pos_in_buf = 0;
 719         loff_t first_entry_in_buffer;
 720         loff_t index_to_find = pos;
 721         struct cifsFileInfo *cfile = file->private_data;
 722         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 723         struct TCP_Server_Info *server = tcon->ses->server;
 724         /* check if index in the buffer */
 725
 726         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 727                 return -ENOSYS;
 728
 729         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 730                 return -ENOENT;
 731
 732         *current_entry = NULL;
 733         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 734                                         cfile->srch_inf.entries_in_buffer;
 735
 736         /*
 737          * If first entry in buf is zero then is first buffer
 738          * in search response data which means it is likely . and ..
 739          * will be in this buffer, although some servers do not return
 740          * . and .. for the root of a drive and for those we need
 741          * to start two entries earlier.
 742          */
 743
 744         dump_cifs_file_struct(file, "In fce ");
 745         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 746              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 747                 /* close and restart search */
 748                 cifs_dbg(FYI, "search backing up - close and restart search\n");
 749                 spin_lock(&cfile->file_info_lock);
 750                 if (server->ops->dir_needs_close(cfile)) {
 751                         cfile->invalidHandle = true;
 752                         spin_unlock(&cfile->file_info_lock);
 753                         if (server->ops->close_dir)
 754                                 server->ops->close_dir(xid, tcon, &cfile->fid);
 755                 } else
 756                         spin_unlock(&cfile->file_info_lock);
 757                 if (cfile->srch_inf.ntwrk_buf_start) {
 758                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
 759                         if (cfile->srch_inf.smallBuf)
 760                                 cifs_small_buf_release(cfile->srch_inf.
 761                                                 ntwrk_buf_start);
 762                         else
 763                                 cifs_buf_release(cfile->srch_inf.
 764                                                 ntwrk_buf_start);
 765                         cfile->srch_inf.ntwrk_buf_start = NULL;
 766                 }
 767                 rc = initiate_cifs_search(xid, file, full_path);
 768                 if (rc) {
 769                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
 770                                  rc);
 771                         return rc;
 772                 }
 773                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 774                 if (cfile->srch_inf.last_entry)
 775                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 776         }
 777
 778         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 779         if (backup_cred(cifs_sb))
 780                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 781
 782         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 783                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 784                 cifs_dbg(FYI, "calling findnext2\n");
 785                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 786                                                  search_flags,
 787                                                  &cfile->srch_inf);
 788                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 789                 if (cfile->srch_inf.last_entry)
 790                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 791                 if (rc)
 792                         return -ENOENT;
 793         }
 794         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 795                 /* we found the buffer that contains the entry */
 796                 /* scan and find it */
 797                 int i;
 798                 char *cur_ent;
 799                 char *end_of_smb;
 800
 801                 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
 802                         cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
 803                         return -EIO;
 804                 }
 805
 806                 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 807                         server->ops->calc_smb_size(
 808                                         cfile->srch_inf.ntwrk_buf_start,
 809                                         server);
 810
 811                 cur_ent = cfile->srch_inf.srch_entries_start;
 812                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 813                                         - cfile->srch_inf.entries_in_buffer;
 814                 pos_in_buf = index_to_find - first_entry_in_buffer;
 815                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
 816
 817                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 818                         /* go entry by entry figuring out which is first */
 819                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 820                                                 cfile->srch_inf.info_level);
 821                 }
 822                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 823                         /* BB fixme - check if we should flag this error */
 824                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
 825                                  pos_in_buf, index_to_find, rc);
 826                 }
 827                 rc = 0;
 828                 *current_entry = cur_ent;
 829         } else {
 830                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
 831                 return 0;
 832         }
 833
 834         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 835                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
 836                 *num_to_ret = 0;
 837         } else
 838                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 839
 840         return rc;
 841 }
 842
 843 static int cifs_filldir(char *find_entry, struct file *file,
 844                 struct dir_context *ctx,
 845                 char *scratch_buf, unsigned int max_len)
 846 {
 847         struct cifsFileInfo *file_info = file->private_data;
 848         struct super_block *sb = file_inode(file)->i_sb;
 849         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 850         struct cifs_dirent de = { NULL, };
 851         struct cifs_fattr fattr;
 852         struct qstr name;
 853         int rc = 0;
 854         ino_t ino;
 855
 856         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 857                               file_info->srch_inf.unicode);
 858         if (rc)
 859                 return rc;
 860
 861         if (de.namelen > max_len) {
 862                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
 863                          de.namelen);
 864                 return -EINVAL;
 865         }
 866
 867         /* skip . and .. since we added them first */
 868         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 869                 return 0;
 870
 871         if (file_info->srch_inf.unicode) {
 872                 struct nls_table *nlt = cifs_sb->local_nls;
 873                 int map_type;
 874
 875                 map_type = cifs_remap(cifs_sb);
 876                 name.name = scratch_buf;
 877                 name.len =
 878                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 879                                         UNICODE_NAME_MAX,
 880                                         min_t(size_t, de.namelen,
 881                                               (size_t)max_len), nlt, map_type);
 882                 name.len -= nls_nullsize(nlt);
 883         } else {
 884                 name.name = de.name;
 885                 name.len = de.namelen;
 886         }
 887
 888         switch (file_info->srch_inf.info_level) {
 889         case SMB_FIND_FILE_POSIX_INFO:
 890                 cifs_posix_to_fattr(&fattr,
 891                                     (struct smb2_posix_info *)find_entry,
 892                                     cifs_sb);
 893                 break;
 894         case SMB_FIND_FILE_UNIX:
 895                 cifs_unix_basic_to_fattr(&fattr,
 896                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 897                                          cifs_sb);
 898                 break;
 899         case SMB_FIND_FILE_INFO_STANDARD:
 900                 cifs_std_info_to_fattr(&fattr,
 901                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 902                                        cifs_sb);
 903                 break;
 904         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 905                 cifs_fulldir_info_to_fattr(&fattr,
 906                                            (SEARCH_ID_FULL_DIR_INFO *)find_entry,
 907                                            cifs_sb);
 908                 break;
 909         default:
 910                 cifs_dir_info_to_fattr(&fattr,
 911                                        (FILE_DIRECTORY_INFO *)find_entry,
 912                                        cifs_sb);
 913                 break;
 914         }
 915
 916         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 917                 fattr.cf_uniqueid = de.ino;
 918         } else {
 919                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 920                 cifs_autodisable_serverino(cifs_sb);
 921         }
 922
 923         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 924             couldbe_mf_symlink(&fattr))
 925                 /*
 926                  * trying to get the type and mode can be slow,
 927                  * so just call those regular files for now, and mark
 928                  * for reval
 929                  */
 930                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 931
 932         cifs_prime_dcache(file_dentry(file), &name, &fattr);
 933
 934         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 935         return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
 936 }
 937
 938
 939 int cifs_readdir(struct file *file, struct dir_context *ctx)
 940 {
 941         int rc = 0;
 942         unsigned int xid;
 943         int i;
 944         struct cifs_tcon *tcon;
 945         struct cifsFileInfo *cifsFile = NULL;
 946         char *current_entry;
 947         int num_to_fill = 0;
 948         char *tmp_buf = NULL;
 949         char *end_of_smb;
 950         unsigned int max_len;
 951         const char *full_path;
 952         void *page = alloc_dentry_path();
 953
 954         xid = get_xid();
 955
 956         full_path = build_path_from_dentry(file_dentry(file), page);
 957         if (IS_ERR(full_path)) {
 958                 rc = PTR_ERR(full_path);
 959                 goto rddir2_exit;
 960         }
 961
 962         /*
 963          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 964          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 965          */
 966         if (file->private_data == NULL) {
 967                 rc = initiate_cifs_search(xid, file, full_path);
 968                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
 969                 if (rc)
 970                         goto rddir2_exit;
 971         }
 972
 973         if (!dir_emit_dots(file, ctx))
 974                 goto rddir2_exit;
 975
 976         /* 1) If search is active,
 977                 is in current search buffer?
 978                 if it before then restart search
 979                 if after then keep searching till find it */
 980
 981         cifsFile = file->private_data;
 982         if (cifsFile->srch_inf.endOfSearch) {
 983                 if (cifsFile->srch_inf.emptyDir) {
 984                         cifs_dbg(FYI, "End of search, empty dir\n");
 985                         rc = 0;
 986                         goto rddir2_exit;
 987                 }
 988         } /* else {
 989                 cifsFile->invalidHandle = true;
 990                 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
 991         } */
 992
 993         tcon = tlink_tcon(cifsFile->tlink);
 994         rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path,
 995                              &current_entry, &num_to_fill);
 996         if (rc) {
 997                 cifs_dbg(FYI, "fce error %d\n", rc);
 998                 goto rddir2_exit;
 999         } else if (current_entry != NULL) {
1000                 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
1001         } else {
1002                 cifs_dbg(FYI, "Could not find entry\n");
1003                 goto rddir2_exit;
1004         }
1005         cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
1006                  num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
1007         max_len = tcon->ses->server->ops->calc_smb_size(
1008                         cifsFile->srch_inf.ntwrk_buf_start,
1009                         tcon->ses->server);
1010         end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
1011
1012         tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
1013         if (tmp_buf == NULL) {
1014                 rc = -ENOMEM;
1015                 goto rddir2_exit;
1016         }
1017
1018         for (i = 0; i < num_to_fill; i++) {
1019                 if (current_entry == NULL) {
1020                         /* evaluate whether this case is an error */
1021                         cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
1022                                  num_to_fill, i);
1023                         break;
1024                 }
1025                 /*
1026                  * if buggy server returns . and .. late do we want to
1027                  * check for that here?
1028                  */
1029                 *tmp_buf = 0;
1030                 rc = cifs_filldir(current_entry, file, ctx,
1031                                   tmp_buf, max_len);
1032                 if (rc) {
1033                         if (rc > 0)
1034                                 rc = 0;
1035                         break;
1036                 }
1037
1038                 ctx->pos++;
1039                 if (ctx->pos ==
1040                         cifsFile->srch_inf.index_of_last_entry) {
1041                         cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
1042                                  ctx->pos, tmp_buf);
1043                         cifs_save_resume_key(current_entry, cifsFile);
1044                         break;
1045                 } else
1046                         current_entry =
1047                                 nxt_dir_entry(current_entry, end_of_smb,
1048                                         cifsFile->srch_inf.info_level);
1049         }
1050         kfree(tmp_buf);
1051
1052 rddir2_exit:
1053         free_dentry_path(page);
1054         free_xid(xid);
1055         return rc;
1056 }