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         /*
 172          * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they
 173          * are preferred by the Linux client in some cases since, unlike
 174          * the NFS reparse tag (or EAs), they don't require an extra query
 175          * to determine which type of special file they represent.
 176          * TODO: go through all documented  reparse tags to see if we can
 177          * reasonably map some of them to directories vs. files vs. symlinks
 178          */
 179         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 180                 fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 181                 fattr->cf_dtype = DT_DIR;
 182         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_SYMLINK) {
 183                 fattr->cf_mode |= S_IFLNK | cifs_sb->mnt_file_mode;
 184                 fattr->cf_dtype = DT_LNK;
 185         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_FIFO) {
 186                 fattr->cf_mode |= S_IFIFO | cifs_sb->mnt_file_mode;
 187                 fattr->cf_dtype = DT_FIFO;
 188         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_AF_UNIX) {
 189                 fattr->cf_mode |= S_IFSOCK | cifs_sb->mnt_file_mode;
 190                 fattr->cf_dtype = DT_SOCK;
 191         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_CHR) {
 192                 fattr->cf_mode |= S_IFCHR | cifs_sb->mnt_file_mode;
 193                 fattr->cf_dtype = DT_CHR;
 194         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_BLK) {
 195                 fattr->cf_mode |= S_IFBLK | cifs_sb->mnt_file_mode;
 196                 fattr->cf_dtype = DT_BLK;
 197         } else { /* TODO: should we mark some other reparse points (like DFSR) as directories? */
 198                 fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 199                 fattr->cf_dtype = DT_REG;
 200         }
 201
 202         /*
 203          * We need to revalidate it further to make a decision about whether it
 204          * is a symbolic link, DFS referral or a reparse point with a direct
 205          * access like junctions, deduplicated files, NFS symlinks.
 206          */
 207         if (reparse_file_needs_reval(fattr))
 208                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 209
 210         /* non-unix readdir doesn't provide nlink */
 211         fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
 212
 213         if (fattr->cf_cifsattrs & ATTR_READONLY)
 214                 fattr->cf_mode &= ~S_IWUGO;
 215
 216         /*
 217          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 218          * mark it for revalidation so that "ls -l" will look right. It might
 219          * be super-slow, but if we don't do this then the ownership of files
 220          * may look wrong since the inodes may not have timed out by the time
 221          * "ls" does a stat() call on them.
 222          */
 223         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
 224             (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
 225                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 226
 227         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 228             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 229                 if (fattr->cf_eof == 0)  {
 230                         fattr->cf_mode &= ~S_IFMT;
 231                         fattr->cf_mode |= S_IFIFO;
 232                         fattr->cf_dtype = DT_FIFO;
 233                 } else {
 234                         /*
 235                          * trying to get the type and mode via SFU can be slow,
 236                          * so just call those regular files for now, and mark
 237                          * for reval
 238                          */
 239                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 240                 }
 241         }
 242 }
 243
 244 /* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
 245 static void
 246 cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
 247                     struct cifs_sb_info *cifs_sb)
 248 {
 249         struct smb2_posix_info_parsed parsed;
 250
 251         posix_info_parse(info, NULL, &parsed);
 252
 253         memset(fattr, 0, sizeof(*fattr));
 254         fattr->cf_uniqueid = le64_to_cpu(info->Inode);
 255         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 256         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 257
 258         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 259         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 260         fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
 261
 262         fattr->cf_nlink = le32_to_cpu(info->HardLinks);
 263         fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
 264
 265         /*
 266          * Since we set the inode type below we need to mask off
 267          * to avoid strange results if bits set above.
 268          * XXX: why not make server&client use the type bits?
 269          */
 270         fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
 271
 272         cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
 273                  le32_to_cpu(info->DeviceId),
 274                  le32_to_cpu(info->ReparseTag),
 275                  le32_to_cpu(info->Mode));
 276
 277         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 278                 fattr->cf_mode |= S_IFDIR;
 279                 fattr->cf_dtype = DT_DIR;
 280         } else {
 281                 /*
 282                  * mark anything that is not a dir as regular
 283                  * file. special files should have the REPARSE
 284                  * attribute and will be marked as needing revaluation
 285                  */
 286                 fattr->cf_mode |= S_IFREG;
 287                 fattr->cf_dtype = DT_REG;
 288         }
 289
 290         if (reparse_file_needs_reval(fattr))
 291                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 292
 293         sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER);
 294         sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP);
 295 }
 296
 297 static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
 298 {
 299         const FILE_DIRECTORY_INFO *fi = info;
 300
 301         memset(fattr, 0, sizeof(*fattr));
 302         fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
 303         fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
 304         fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
 305         fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
 306         fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);
 307         fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);
 308         fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);
 309 }
 310
 311 void
 312 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 313                        struct cifs_sb_info *cifs_sb)
 314 {
 315         __dir_info_to_fattr(fattr, info);
 316         cifs_fill_common_info(fattr, cifs_sb);
 317 }
 318
 319 static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
 320                                        SEARCH_ID_FULL_DIR_INFO *info,
 321                                        struct cifs_sb_info *cifs_sb)
 322 {
 323         __dir_info_to_fattr(fattr, info);
 324
 325         /* See MS-FSCC 2.4.18 FileIdFullDirectoryInformation */
 326         if (fattr->cf_cifsattrs & ATTR_REPARSE)
 327                 fattr->cf_cifstag = le32_to_cpu(info->EaSize);
 328         cifs_fill_common_info(fattr, cifs_sb);
 329 }
 330
 331 static void
 332 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 333                        struct cifs_sb_info *cifs_sb)
 334 {
 335         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 336
 337         memset(fattr, 0, sizeof(*fattr));
 338         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 339                                             info->LastAccessTime, offset);
 340         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 341                                             info->LastWriteTime, offset);
 342         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 343                                             info->LastWriteTime, offset);
 344
 345         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 346         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 347         fattr->cf_eof = le32_to_cpu(info->DataSize);
 348
 349         cifs_fill_common_info(fattr, cifs_sb);
 350 }
 351
 352 /* BB eventually need to add the following helper function to
 353       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 354       we try to do FindFirst on (NTFS) directory symlinks */
 355 /*
 356 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 357                              unsigned int xid)
 358 {
 359         __u16 fid;
 360         int len;
 361         int oplock = 0;
 362         int rc;
 363         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 364         char *tmpbuffer;
 365
 366         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 367                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 368                         cifs_sb->local_nls,
 369                         cifs_remap(cifs_sb);
 370         if (!rc) {
 371                 tmpbuffer = kmalloc(maxpath);
 372                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 373                                 tmpbuffer,
 374                                 maxpath -1,
 375                                 fid,
 376                                 cifs_sb->local_nls);
 377                 if (CIFSSMBClose(xid, ptcon, fid)) {
 378                         cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
 379                 }
 380         }
 381 }
 382  */
 383
 384 static int
 385 initiate_cifs_search(const unsigned int xid, struct file *file,
 386                      char *full_path)
 387 {
 388         __u16 search_flags;
 389         int rc = 0;
 390         struct cifsFileInfo *cifsFile;
 391         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 392         struct tcon_link *tlink = NULL;
 393         struct cifs_tcon *tcon;
 394         struct TCP_Server_Info *server;
 395
 396         if (file->private_data == NULL) {
 397                 tlink = cifs_sb_tlink(cifs_sb);
 398                 if (IS_ERR(tlink))
 399                         return PTR_ERR(tlink);
 400
 401                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 402                 if (cifsFile == NULL) {
 403                         rc = -ENOMEM;
 404                         goto error_exit;
 405                 }
 406                 spin_lock_init(&cifsFile->file_info_lock);
 407                 file->private_data = cifsFile;
 408                 cifsFile->tlink = cifs_get_tlink(tlink);
 409                 tcon = tlink_tcon(tlink);
 410         } else {
 411                 cifsFile = file->private_data;
 412                 tcon = tlink_tcon(cifsFile->tlink);
 413         }
 414
 415         server = tcon->ses->server;
 416
 417         if (!server->ops->query_dir_first) {
 418                 rc = -ENOSYS;
 419                 goto error_exit;
 420         }
 421
 422         cifsFile->invalidHandle = true;
 423         cifsFile->srch_inf.endOfSearch = false;
 424
 425         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
 426
 427 ffirst_retry:
 428         /* test for Unix extensions */
 429         /* but now check for them on the share/mount not on the SMB session */
 430         /* if (cap_unix(tcon->ses) { */
 431         if (tcon->unix_ext)
 432                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 433         else if (tcon->posix_extensions)
 434                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
 435         else if ((tcon->ses->capabilities &
 436                   tcon->ses->server->vals->cap_nt_find) == 0) {
 437                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 438         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 439                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 440         } else /* not srvinos - BB fixme add check for backlevel? */ {
 441                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 442         }
 443
 444         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 445         if (backup_cred(cifs_sb))
 446                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 447
 448         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 449                                           &cifsFile->fid, search_flags,
 450                                           &cifsFile->srch_inf);
 451
 452         if (rc == 0)
 453                 cifsFile->invalidHandle = false;
 454         /* BB add following call to handle readdir on new NTFS symlink errors
 455         else if STATUS_STOPPED_ON_SYMLINK
 456                 call get_symlink_reparse_path and retry with new path */
 457         else if ((rc == -EOPNOTSUPP) &&
 458                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 459                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 460                 goto ffirst_retry;
 461         }
 462 error_exit:
 463         cifs_put_tlink(tlink);
 464         return rc;
 465 }
 466
 467 /* return length of unicode string in bytes */
 468 static int cifs_unicode_bytelen(const char *str)
 469 {
 470         int len;
 471         const __le16 *ustr = (const __le16 *)str;
 472
 473         for (len = 0; len <= PATH_MAX; len++) {
 474                 if (ustr[len] == 0)
 475                         return len << 1;
 476         }
 477         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
 478         return len << 1;
 479 }
 480
 481 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 482 {
 483         char *new_entry;
 484         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 485
 486         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 487                 FIND_FILE_STANDARD_INFO *pfData;
 488                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 489
 490                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 491                                 pfData->FileNameLength;
 492         } else {
 493                 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
 494
 495                 if (old_entry + next_offset < old_entry) {
 496                         cifs_dbg(VFS, "Invalid offset %u\n", next_offset);
 497                         return NULL;
 498                 }
 499                 new_entry = old_entry + next_offset;
 500         }
 501         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
 502         /* validate that new_entry is not past end of SMB */
 503         if (new_entry >= end_of_smb) {
 504                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
 505                          new_entry, end_of_smb, old_entry);
 506                 return NULL;
 507         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 508                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 509                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 510                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 511                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
 512                          new_entry, end_of_smb);
 513                 return NULL;
 514         } else
 515                 return new_entry;
 516
 517 }
 518
 519 struct cifs_dirent {
 520         const char      *name;
 521         size_t          namelen;
 522         u32             resume_key;
 523         u64             ino;
 524 };
 525
 526 static void cifs_fill_dirent_posix(struct cifs_dirent *de,
 527                                    const struct smb2_posix_info *info)
 528 {
 529         struct smb2_posix_info_parsed parsed;
 530
 531         /* payload should have already been checked at this point */
 532         if (posix_info_parse(info, NULL, &parsed) < 0) {
 533                 cifs_dbg(VFS, "Invalid POSIX info payload\n");
 534                 return;
 535         }
 536
 537         de->name = parsed.name;
 538         de->namelen = parsed.name_len;
 539         de->resume_key = info->Ignored;
 540         de->ino = le64_to_cpu(info->Inode);
 541 }
 542
 543 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 544                 const FILE_UNIX_INFO *info, bool is_unicode)
 545 {
 546         de->name = &info->FileName[0];
 547         if (is_unicode)
 548                 de->namelen = cifs_unicode_bytelen(de->name);
 549         else
 550                 de->namelen = strnlen(de->name, PATH_MAX);
 551         de->resume_key = info->ResumeKey;
 552         de->ino = le64_to_cpu(info->basic.UniqueId);
 553 }
 554
 555 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 556                 const FILE_DIRECTORY_INFO *info)
 557 {
 558         de->name = &info->FileName[0];
 559         de->namelen = le32_to_cpu(info->FileNameLength);
 560         de->resume_key = info->FileIndex;
 561 }
 562
 563 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 564                 const FILE_FULL_DIRECTORY_INFO *info)
 565 {
 566         de->name = &info->FileName[0];
 567         de->namelen = le32_to_cpu(info->FileNameLength);
 568         de->resume_key = info->FileIndex;
 569 }
 570
 571 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 572                 const SEARCH_ID_FULL_DIR_INFO *info)
 573 {
 574         de->name = &info->FileName[0];
 575         de->namelen = le32_to_cpu(info->FileNameLength);
 576         de->resume_key = info->FileIndex;
 577         de->ino = le64_to_cpu(info->UniqueId);
 578 }
 579
 580 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 581                 const FILE_BOTH_DIRECTORY_INFO *info)
 582 {
 583         de->name = &info->FileName[0];
 584         de->namelen = le32_to_cpu(info->FileNameLength);
 585         de->resume_key = info->FileIndex;
 586 }
 587
 588 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 589                 const FIND_FILE_STANDARD_INFO *info)
 590 {
 591         de->name = &info->FileName[0];
 592         /* one byte length, no endianess conversion */
 593         de->namelen = info->FileNameLength;
 594         de->resume_key = info->ResumeKey;
 595 }
 596
 597 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 598                 u16 level, bool is_unicode)
 599 {
 600         memset(de, 0, sizeof(*de));
 601
 602         switch (level) {
 603         case SMB_FIND_FILE_POSIX_INFO:
 604                 cifs_fill_dirent_posix(de, info);
 605                 break;
 606         case SMB_FIND_FILE_UNIX:
 607                 cifs_fill_dirent_unix(de, info, is_unicode);
 608                 break;
 609         case SMB_FIND_FILE_DIRECTORY_INFO:
 610                 cifs_fill_dirent_dir(de, info);
 611                 break;
 612         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 613                 cifs_fill_dirent_full(de, info);
 614                 break;
 615         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 616                 cifs_fill_dirent_search(de, info);
 617                 break;
 618         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 619                 cifs_fill_dirent_both(de, info);
 620                 break;
 621         case SMB_FIND_FILE_INFO_STANDARD:
 622                 cifs_fill_dirent_std(de, info);
 623                 break;
 624         default:
 625                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
 626                 return -EINVAL;
 627         }
 628
 629         return 0;
 630 }
 631
 632 #define UNICODE_DOT cpu_to_le16(0x2e)
 633
 634 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 635 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 636 {
 637         int rc = 0;
 638
 639         if (!de->name)
 640                 return 0;
 641
 642         if (is_unicode) {
 643                 __le16 *ufilename = (__le16 *)de->name;
 644                 if (de->namelen == 2) {
 645                         /* check for . */
 646                         if (ufilename[0] == UNICODE_DOT)
 647                                 rc = 1;
 648                 } else if (de->namelen == 4) {
 649                         /* check for .. */
 650                         if (ufilename[0] == UNICODE_DOT &&
 651                             ufilename[1] == UNICODE_DOT)
 652                                 rc = 2;
 653                 }
 654         } else /* ASCII */ {
 655                 if (de->namelen == 1) {
 656                         if (de->name[0] == '.')
 657                                 rc = 1;
 658                 } else if (de->namelen == 2) {
 659                         if (de->name[0] == '.' && de->name[1] == '.')
 660                                 rc = 2;
 661                 }
 662         }
 663
 664         return rc;
 665 }
 666
 667 /* Check if directory that we are searching has changed so we can decide
 668    whether we can use the cached search results from the previous search */
 669 static int is_dir_changed(struct file *file)
 670 {
 671         struct inode *inode = file_inode(file);
 672         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 673
 674         if (cifsInfo->time == 0)
 675                 return 1; /* directory was changed, perhaps due to unlink */
 676         else
 677                 return 0;
 678
 679 }
 680
 681 static int cifs_save_resume_key(const char *current_entry,
 682         struct cifsFileInfo *file_info)
 683 {
 684         struct cifs_dirent de;
 685         int rc;
 686
 687         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 688                               file_info->srch_inf.unicode);
 689         if (!rc) {
 690                 file_info->srch_inf.presume_name = de.name;
 691                 file_info->srch_inf.resume_name_len = de.namelen;
 692                 file_info->srch_inf.resume_key = de.resume_key;
 693         }
 694         return rc;
 695 }
 696
 697 /*
 698  * Find the corresponding entry in the search. Note that the SMB server returns
 699  * search entries for . and .. which complicates logic here if we choose to
 700  * parse for them and we do not assume that they are located in the findfirst
 701  * return buffer. We start counting in the buffer with entry 2 and increment for
 702  * every entry (do not increment for . or .. entry).
 703  */
 704 static int
 705 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
 706                 struct file *file, char *full_path,
 707                 char **current_entry, int *num_to_ret)
 708 {
 709         __u16 search_flags;
 710         int rc = 0;
 711         int pos_in_buf = 0;
 712         loff_t first_entry_in_buffer;
 713         loff_t index_to_find = pos;
 714         struct cifsFileInfo *cfile = file->private_data;
 715         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 716         struct TCP_Server_Info *server = tcon->ses->server;
 717         /* check if index in the buffer */
 718
 719         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 720                 return -ENOSYS;
 721
 722         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 723                 return -ENOENT;
 724
 725         *current_entry = NULL;
 726         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 727                                         cfile->srch_inf.entries_in_buffer;
 728
 729         /*
 730          * If first entry in buf is zero then is first buffer
 731          * in search response data which means it is likely . and ..
 732          * will be in this buffer, although some servers do not return
 733          * . and .. for the root of a drive and for those we need
 734          * to start two entries earlier.
 735          */
 736
 737         dump_cifs_file_struct(file, "In fce ");
 738         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 739              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 740                 /* close and restart search */
 741                 cifs_dbg(FYI, "search backing up - close and restart search\n");
 742                 spin_lock(&cfile->file_info_lock);
 743                 if (server->ops->dir_needs_close(cfile)) {
 744                         cfile->invalidHandle = true;
 745                         spin_unlock(&cfile->file_info_lock);
 746                         if (server->ops->close_dir)
 747                                 server->ops->close_dir(xid, tcon, &cfile->fid);
 748                 } else
 749                         spin_unlock(&cfile->file_info_lock);
 750                 if (cfile->srch_inf.ntwrk_buf_start) {
 751                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
 752                         if (cfile->srch_inf.smallBuf)
 753                                 cifs_small_buf_release(cfile->srch_inf.
 754                                                 ntwrk_buf_start);
 755                         else
 756                                 cifs_buf_release(cfile->srch_inf.
 757                                                 ntwrk_buf_start);
 758                         cfile->srch_inf.ntwrk_buf_start = NULL;
 759                 }
 760                 rc = initiate_cifs_search(xid, file, full_path);
 761                 if (rc) {
 762                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
 763                                  rc);
 764                         return rc;
 765                 }
 766                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 767                 if (cfile->srch_inf.last_entry)
 768                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 769         }
 770
 771         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 772         if (backup_cred(cifs_sb))
 773                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 774
 775         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 776                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 777                 cifs_dbg(FYI, "calling findnext2\n");
 778                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 779                                                  search_flags,
 780                                                  &cfile->srch_inf);
 781                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 782                 if (cfile->srch_inf.last_entry)
 783                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 784                 if (rc)
 785                         return -ENOENT;
 786         }
 787         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 788                 /* we found the buffer that contains the entry */
 789                 /* scan and find it */
 790                 int i;
 791                 char *cur_ent;
 792                 char *end_of_smb;
 793
 794                 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
 795                         cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
 796                         return -EIO;
 797                 }
 798
 799                 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 800                         server->ops->calc_smb_size(
 801                                         cfile->srch_inf.ntwrk_buf_start,
 802                                         server);
 803
 804                 cur_ent = cfile->srch_inf.srch_entries_start;
 805                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 806                                         - cfile->srch_inf.entries_in_buffer;
 807                 pos_in_buf = index_to_find - first_entry_in_buffer;
 808                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
 809
 810                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 811                         /* go entry by entry figuring out which is first */
 812                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 813                                                 cfile->srch_inf.info_level);
 814                 }
 815                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 816                         /* BB fixme - check if we should flag this error */
 817                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
 818                                  pos_in_buf, index_to_find, rc);
 819                 }
 820                 rc = 0;
 821                 *current_entry = cur_ent;
 822         } else {
 823                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
 824                 return 0;
 825         }
 826
 827         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 828                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
 829                 *num_to_ret = 0;
 830         } else
 831                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 832
 833         return rc;
 834 }
 835
 836 static int cifs_filldir(char *find_entry, struct file *file,
 837                 struct dir_context *ctx,
 838                 char *scratch_buf, unsigned int max_len)
 839 {
 840         struct cifsFileInfo *file_info = file->private_data;
 841         struct super_block *sb = file_inode(file)->i_sb;
 842         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 843         struct cifs_dirent de = { NULL, };
 844         struct cifs_fattr fattr;
 845         struct qstr name;
 846         int rc = 0;
 847         ino_t ino;
 848
 849         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 850                               file_info->srch_inf.unicode);
 851         if (rc)
 852                 return rc;
 853
 854         if (de.namelen > max_len) {
 855                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
 856                          de.namelen);
 857                 return -EINVAL;
 858         }
 859
 860         /* skip . and .. since we added them first */
 861         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 862                 return 0;
 863
 864         if (file_info->srch_inf.unicode) {
 865                 struct nls_table *nlt = cifs_sb->local_nls;
 866                 int map_type;
 867
 868                 map_type = cifs_remap(cifs_sb);
 869                 name.name = scratch_buf;
 870                 name.len =
 871                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 872                                         UNICODE_NAME_MAX,
 873                                         min_t(size_t, de.namelen,
 874                                               (size_t)max_len), nlt, map_type);
 875                 name.len -= nls_nullsize(nlt);
 876         } else {
 877                 name.name = de.name;
 878                 name.len = de.namelen;
 879         }
 880
 881         switch (file_info->srch_inf.info_level) {
 882         case SMB_FIND_FILE_POSIX_INFO:
 883                 cifs_posix_to_fattr(&fattr,
 884                                     (struct smb2_posix_info *)find_entry,
 885                                     cifs_sb);
 886                 break;
 887         case SMB_FIND_FILE_UNIX:
 888                 cifs_unix_basic_to_fattr(&fattr,
 889                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 890                                          cifs_sb);
 891                 break;
 892         case SMB_FIND_FILE_INFO_STANDARD:
 893                 cifs_std_info_to_fattr(&fattr,
 894                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 895                                        cifs_sb);
 896                 break;
 897         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 898                 cifs_fulldir_info_to_fattr(&fattr,
 899                                            (SEARCH_ID_FULL_DIR_INFO *)find_entry,
 900                                            cifs_sb);
 901                 break;
 902         default:
 903                 cifs_dir_info_to_fattr(&fattr,
 904                                        (FILE_DIRECTORY_INFO *)find_entry,
 905                                        cifs_sb);
 906                 break;
 907         }
 908
 909         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 910                 fattr.cf_uniqueid = de.ino;
 911         } else {
 912                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 913                 cifs_autodisable_serverino(cifs_sb);
 914         }
 915
 916         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 917             couldbe_mf_symlink(&fattr))
 918                 /*
 919                  * trying to get the type and mode can be slow,
 920                  * so just call those regular files for now, and mark
 921                  * for reval
 922                  */
 923                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 924
 925         cifs_prime_dcache(file_dentry(file), &name, &fattr);
 926
 927         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 928         return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
 929 }
 930
 931
 932 int cifs_readdir(struct file *file, struct dir_context *ctx)
 933 {
 934         int rc = 0;
 935         unsigned int xid;
 936         int i;
 937         struct cifs_tcon *tcon;
 938         struct cifsFileInfo *cifsFile = NULL;
 939         char *current_entry;
 940         int num_to_fill = 0;
 941         char *tmp_buf = NULL;
 942         char *end_of_smb;
 943         unsigned int max_len;
 944         char *full_path = NULL;
 945
 946         xid = get_xid();
 947
 948         full_path = build_path_from_dentry(file_dentry(file));
 949         if (full_path == NULL) {
 950                 rc = -ENOMEM;
 951                 goto rddir2_exit;
 952         }
 953
 954         /*
 955          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 956          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 957          */
 958         if (file->private_data == NULL) {
 959                 rc = initiate_cifs_search(xid, file, full_path);
 960                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
 961                 if (rc)
 962                         goto rddir2_exit;
 963         }
 964
 965         if (!dir_emit_dots(file, ctx))
 966                 goto rddir2_exit;
 967
 968         /* 1) If search is active,
 969                 is in current search buffer?
 970                 if it before then restart search
 971                 if after then keep searching till find it */
 972
 973         cifsFile = file->private_data;
 974         if (cifsFile->srch_inf.endOfSearch) {
 975                 if (cifsFile->srch_inf.emptyDir) {
 976                         cifs_dbg(FYI, "End of search, empty dir\n");
 977                         rc = 0;
 978                         goto rddir2_exit;
 979                 }
 980         } /* else {
 981                 cifsFile->invalidHandle = true;
 982                 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
 983         } */
 984
 985         tcon = tlink_tcon(cifsFile->tlink);
 986         rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path,
 987                              &current_entry, &num_to_fill);
 988         if (rc) {
 989                 cifs_dbg(FYI, "fce error %d\n", rc);
 990                 goto rddir2_exit;
 991         } else if (current_entry != NULL) {
 992                 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
 993         } else {
 994                 cifs_dbg(FYI, "Could not find entry\n");
 995                 goto rddir2_exit;
 996         }
 997         cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
 998                  num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 999         max_len = tcon->ses->server->ops->calc_smb_size(
1000                         cifsFile->srch_inf.ntwrk_buf_start,
1001                         tcon->ses->server);
1002         end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
1003
1004         tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
1005         if (tmp_buf == NULL) {
1006                 rc = -ENOMEM;
1007                 goto rddir2_exit;
1008         }
1009
1010         for (i = 0; i < num_to_fill; i++) {
1011                 if (current_entry == NULL) {
1012                         /* evaluate whether this case is an error */
1013                         cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
1014                                  num_to_fill, i);
1015                         break;
1016                 }
1017                 /*
1018                  * if buggy server returns . and .. late do we want to
1019                  * check for that here?
1020                  */
1021                 *tmp_buf = 0;
1022                 rc = cifs_filldir(current_entry, file, ctx,
1023                                   tmp_buf, max_len);
1024                 if (rc) {
1025                         if (rc > 0)
1026                                 rc = 0;
1027                         break;
1028                 }
1029
1030                 ctx->pos++;
1031                 if (ctx->pos ==
1032                         cifsFile->srch_inf.index_of_last_entry) {
1033                         cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
1034                                  ctx->pos, tmp_buf);
1035                         cifs_save_resume_key(current_entry, cifsFile);
1036                         break;
1037                 } else
1038                         current_entry =
1039                                 nxt_dir_entry(current_entry, end_of_smb,
1040                                         cifsFile->srch_inf.info_level);
1041         }
1042         kfree(tmp_buf);
1043
1044 rddir2_exit:
1045         kfree(full_path);
1046         free_xid(xid);
1047         return rc;
1048 }