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 #include "fs_context.h"
  37
  38 /*
  39  * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  40  * characters alloc more to account for such multibyte target UTF-8
  41  * characters.
  42  */
  43 #define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  44
  45 #ifdef CONFIG_CIFS_DEBUG2
  46 static void dump_cifs_file_struct(struct file *file, char *label)
  47 {
  48         struct cifsFileInfo *cf;
  49
  50         if (file) {
  51                 cf = file->private_data;
  52                 if (cf == NULL) {
  53                         cifs_dbg(FYI, "empty cifs private file data\n");
  54                         return;
  55                 }
  56                 if (cf->invalidHandle)
  57                         cifs_dbg(FYI, "Invalid handle\n");
  58                 if (cf->srch_inf.endOfSearch)
  59                         cifs_dbg(FYI, "end of search\n");
  60                 if (cf->srch_inf.emptyDir)
  61                         cifs_dbg(FYI, "empty dir\n");
  62         }
  63 }
  64 #else
  65 static inline void dump_cifs_file_struct(struct file *file, char *label)
  66 {
  67 }
  68 #endif /* DEBUG2 */
  69
  70 /*
  71  * Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
  72  *
  73  * Find the dentry that matches "name". If there isn't one, create one. If it's
  74  * a negative dentry or the uniqueid or filetype(mode) changed,
  75  * then drop it and recreate it.
  76  */
  77 static void
  78 cifs_prime_dcache(struct dentry *parent, struct qstr *name,
  79                     struct cifs_fattr *fattr)
  80 {
  81         struct dentry *dentry, *alias;
  82         struct inode *inode;
  83         struct super_block *sb = parent->d_sb;
  84         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
  85         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
  86
  87         cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
  88
  89         dentry = d_hash_and_lookup(parent, name);
  90         if (!dentry) {
  91                 /*
  92                  * If we know that the inode will need to be revalidated
  93                  * immediately, then don't create a new dentry for it.
  94                  * We'll end up doing an on the wire call either way and
  95                  * this spares us an invalidation.
  96                  */
  97                 if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
  98                         return;
  99 retry:
 100                 dentry = d_alloc_parallel(parent, name, &wq);
 101         }
 102         if (IS_ERR(dentry))
 103                 return;
 104         if (!d_in_lookup(dentry)) {
 105                 inode = d_inode(dentry);
 106                 if (inode) {
 107                         if (d_mountpoint(dentry)) {
 108                                 dput(dentry);
 109                                 return;
 110                         }
 111                         /*
 112                          * If we're generating inode numbers, then we don't
 113                          * want to clobber the existing one with the one that
 114                          * the readdir code created.
 115                          */
 116                         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
 117                                 fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
 118
 119                         /* update inode in place
 120                          * if both i_ino and i_mode didn't change */
 121                         if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid &&
 122                             (inode->i_mode & S_IFMT) ==
 123                             (fattr->cf_mode & S_IFMT)) {
 124                                 cifs_fattr_to_inode(inode, fattr);
 125                                 dput(dentry);
 126                                 return;
 127                         }
 128                 }
 129                 d_invalidate(dentry);
 130                 dput(dentry);
 131                 goto retry;
 132         } else {
 133                 inode = cifs_iget(sb, fattr);
 134                 if (!inode)
 135                         inode = ERR_PTR(-ENOMEM);
 136                 alias = d_splice_alias(inode, dentry);
 137                 d_lookup_done(dentry);
 138                 if (alias && !IS_ERR(alias))
 139                         dput(alias);
 140         }
 141         dput(dentry);
 142 }
 143
 144 static bool reparse_file_needs_reval(const struct cifs_fattr *fattr)
 145 {
 146         if (!(fattr->cf_cifsattrs & ATTR_REPARSE))
 147                 return false;
 148         /*
 149          * The DFS tags should be only intepreted by server side as per
 150          * MS-FSCC 2.1.2.1, but let's include them anyway.
 151          *
 152          * Besides, if cf_cifstag is unset (0), then we still need it to be
 153          * revalidated to know exactly what reparse point it is.
 154          */
 155         switch (fattr->cf_cifstag) {
 156         case IO_REPARSE_TAG_DFS:
 157         case IO_REPARSE_TAG_DFSR:
 158         case IO_REPARSE_TAG_SYMLINK:
 159         case IO_REPARSE_TAG_NFS:
 160         case 0:
 161                 return true;
 162         }
 163         return false;
 164 }
 165
 166 static void
 167 cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 168 {
 169         fattr->cf_uid = cifs_sb->ctx->linux_uid;
 170         fattr->cf_gid = cifs_sb->ctx->linux_gid;
 171
 172         /*
 173          * The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they
 174          * are preferred by the Linux client in some cases since, unlike
 175          * the NFS reparse tag (or EAs), they don't require an extra query
 176          * to determine which type of special file they represent.
 177          * TODO: go through all documented  reparse tags to see if we can
 178          * reasonably map some of them to directories vs. files vs. symlinks
 179          */
 180         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 181                 fattr->cf_mode = S_IFDIR | cifs_sb->ctx->dir_mode;
 182                 fattr->cf_dtype = DT_DIR;
 183         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_SYMLINK) {
 184                 fattr->cf_mode |= S_IFLNK | cifs_sb->ctx->file_mode;
 185                 fattr->cf_dtype = DT_LNK;
 186         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_FIFO) {
 187                 fattr->cf_mode |= S_IFIFO | cifs_sb->ctx->file_mode;
 188                 fattr->cf_dtype = DT_FIFO;
 189         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_AF_UNIX) {
 190                 fattr->cf_mode |= S_IFSOCK | cifs_sb->ctx->file_mode;
 191                 fattr->cf_dtype = DT_SOCK;
 192         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_CHR) {
 193                 fattr->cf_mode |= S_IFCHR | cifs_sb->ctx->file_mode;
 194                 fattr->cf_dtype = DT_CHR;
 195         } else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_BLK) {
 196                 fattr->cf_mode |= S_IFBLK | cifs_sb->ctx->file_mode;
 197                 fattr->cf_dtype = DT_BLK;
 198         } else { /* TODO: should we mark some other reparse points (like DFSR) as directories? */
 199                 fattr->cf_mode = S_IFREG | cifs_sb->ctx->file_mode;
 200                 fattr->cf_dtype = DT_REG;
 201         }
 202
 203         /*
 204          * We need to revalidate it further to make a decision about whether it
 205          * is a symbolic link, DFS referral or a reparse point with a direct
 206          * access like junctions, deduplicated files, NFS symlinks.
 207          */
 208         if (reparse_file_needs_reval(fattr))
 209                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 210
 211         /* non-unix readdir doesn't provide nlink */
 212         fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
 213
 214         if (fattr->cf_cifsattrs & ATTR_READONLY)
 215                 fattr->cf_mode &= ~S_IWUGO;
 216
 217         /*
 218          * We of course don't get ACL info in FIND_FIRST/NEXT results, so
 219          * mark it for revalidation so that "ls -l" will look right. It might
 220          * be super-slow, but if we don't do this then the ownership of files
 221          * may look wrong since the inodes may not have timed out by the time
 222          * "ls" does a stat() call on them.
 223          */
 224         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
 225             (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
 226                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 227
 228         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 229             fattr->cf_cifsattrs & ATTR_SYSTEM) {
 230                 if (fattr->cf_eof == 0)  {
 231                         fattr->cf_mode &= ~S_IFMT;
 232                         fattr->cf_mode |= S_IFIFO;
 233                         fattr->cf_dtype = DT_FIFO;
 234                 } else {
 235                         /*
 236                          * trying to get the type and mode via SFU can be slow,
 237                          * so just call those regular files for now, and mark
 238                          * for reval
 239                          */
 240                         fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 241                 }
 242         }
 243 }
 244
 245 /* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
 246 static void
 247 cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
 248                     struct cifs_sb_info *cifs_sb)
 249 {
 250         struct smb2_posix_info_parsed parsed;
 251
 252         posix_info_parse(info, NULL, &parsed);
 253
 254         memset(fattr, 0, sizeof(*fattr));
 255         fattr->cf_uniqueid = le64_to_cpu(info->Inode);
 256         fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 257         fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 258
 259         fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 260         fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 261         fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
 262
 263         fattr->cf_nlink = le32_to_cpu(info->HardLinks);
 264         fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
 265
 266         /*
 267          * Since we set the inode type below we need to mask off
 268          * to avoid strange results if bits set above.
 269          * XXX: why not make server&client use the type bits?
 270          */
 271         fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
 272
 273         cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
 274                  le32_to_cpu(info->DeviceId),
 275                  le32_to_cpu(info->ReparseTag),
 276                  le32_to_cpu(info->Mode));
 277
 278         if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 279                 fattr->cf_mode |= S_IFDIR;
 280                 fattr->cf_dtype = DT_DIR;
 281         } else {
 282                 /*
 283                  * mark anything that is not a dir as regular
 284                  * file. special files should have the REPARSE
 285                  * attribute and will be marked as needing revaluation
 286                  */
 287                 fattr->cf_mode |= S_IFREG;
 288                 fattr->cf_dtype = DT_REG;
 289         }
 290
 291         if (reparse_file_needs_reval(fattr))
 292                 fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 293
 294         sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER);
 295         sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP);
 296 }
 297
 298 static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
 299 {
 300         const FILE_DIRECTORY_INFO *fi = info;
 301
 302         memset(fattr, 0, sizeof(*fattr));
 303         fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
 304         fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
 305         fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
 306         fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
 307         fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);
 308         fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);
 309         fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);
 310 }
 311
 312 void
 313 cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 314                        struct cifs_sb_info *cifs_sb)
 315 {
 316         __dir_info_to_fattr(fattr, info);
 317         cifs_fill_common_info(fattr, cifs_sb);
 318 }
 319
 320 static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
 321                                        SEARCH_ID_FULL_DIR_INFO *info,
 322                                        struct cifs_sb_info *cifs_sb)
 323 {
 324         __dir_info_to_fattr(fattr, info);
 325
 326         /* See MS-FSCC 2.4.18 FileIdFullDirectoryInformation */
 327         if (fattr->cf_cifsattrs & ATTR_REPARSE)
 328                 fattr->cf_cifstag = le32_to_cpu(info->EaSize);
 329         cifs_fill_common_info(fattr, cifs_sb);
 330 }
 331
 332 static void
 333 cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 334                        struct cifs_sb_info *cifs_sb)
 335 {
 336         int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 337
 338         memset(fattr, 0, sizeof(*fattr));
 339         fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 340                                             info->LastAccessTime, offset);
 341         fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 342                                             info->LastWriteTime, offset);
 343         fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 344                                             info->LastWriteTime, offset);
 345
 346         fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 347         fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 348         fattr->cf_eof = le32_to_cpu(info->DataSize);
 349
 350         cifs_fill_common_info(fattr, cifs_sb);
 351 }
 352
 353 /* BB eventually need to add the following helper function to
 354       resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 355       we try to do FindFirst on (NTFS) directory symlinks */
 356 /*
 357 int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 358                              unsigned int xid)
 359 {
 360         __u16 fid;
 361         int len;
 362         int oplock = 0;
 363         int rc;
 364         struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 365         char *tmpbuffer;
 366
 367         rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 368                         OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 369                         cifs_sb->local_nls,
 370                         cifs_remap(cifs_sb);
 371         if (!rc) {
 372                 tmpbuffer = kmalloc(maxpath);
 373                 rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 374                                 tmpbuffer,
 375                                 maxpath -1,
 376                                 fid,
 377                                 cifs_sb->local_nls);
 378                 if (CIFSSMBClose(xid, ptcon, fid)) {
 379                         cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
 380                 }
 381         }
 382 }
 383  */
 384
 385 static int
 386 initiate_cifs_search(const unsigned int xid, struct file *file,
 387                      char *full_path)
 388 {
 389         __u16 search_flags;
 390         int rc = 0;
 391         struct cifsFileInfo *cifsFile;
 392         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 393         struct tcon_link *tlink = NULL;
 394         struct cifs_tcon *tcon;
 395         struct TCP_Server_Info *server;
 396
 397         if (file->private_data == NULL) {
 398                 tlink = cifs_sb_tlink(cifs_sb);
 399                 if (IS_ERR(tlink))
 400                         return PTR_ERR(tlink);
 401
 402                 cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 403                 if (cifsFile == NULL) {
 404                         rc = -ENOMEM;
 405                         goto error_exit;
 406                 }
 407                 spin_lock_init(&cifsFile->file_info_lock);
 408                 file->private_data = cifsFile;
 409                 cifsFile->tlink = cifs_get_tlink(tlink);
 410                 tcon = tlink_tcon(tlink);
 411         } else {
 412                 cifsFile = file->private_data;
 413                 tcon = tlink_tcon(cifsFile->tlink);
 414         }
 415
 416         server = tcon->ses->server;
 417
 418         if (!server->ops->query_dir_first) {
 419                 rc = -ENOSYS;
 420                 goto error_exit;
 421         }
 422
 423         cifsFile->invalidHandle = true;
 424         cifsFile->srch_inf.endOfSearch = false;
 425
 426         cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
 427
 428 ffirst_retry:
 429         /* test for Unix extensions */
 430         /* but now check for them on the share/mount not on the SMB session */
 431         /* if (cap_unix(tcon->ses) { */
 432         if (tcon->unix_ext)
 433                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 434         else if (tcon->posix_extensions)
 435                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
 436         else if ((tcon->ses->capabilities &
 437                   tcon->ses->server->vals->cap_nt_find) == 0) {
 438                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 439         } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 440                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 441         } else /* not srvinos - BB fixme add check for backlevel? */ {
 442                 cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 443         }
 444
 445         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 446         if (backup_cred(cifs_sb))
 447                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 448
 449         rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
 450                                           &cifsFile->fid, search_flags,
 451                                           &cifsFile->srch_inf);
 452
 453         if (rc == 0)
 454                 cifsFile->invalidHandle = false;
 455         /* BB add following call to handle readdir on new NTFS symlink errors
 456         else if STATUS_STOPPED_ON_SYMLINK
 457                 call get_symlink_reparse_path and retry with new path */
 458         else if ((rc == -EOPNOTSUPP) &&
 459                 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 460                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 461                 goto ffirst_retry;
 462         }
 463 error_exit:
 464         cifs_put_tlink(tlink);
 465         return rc;
 466 }
 467
 468 /* return length of unicode string in bytes */
 469 static int cifs_unicode_bytelen(const char *str)
 470 {
 471         int len;
 472         const __le16 *ustr = (const __le16 *)str;
 473
 474         for (len = 0; len <= PATH_MAX; len++) {
 475                 if (ustr[len] == 0)
 476                         return len << 1;
 477         }
 478         cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
 479         return len << 1;
 480 }
 481
 482 static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 483 {
 484         char *new_entry;
 485         FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 486
 487         if (level == SMB_FIND_FILE_INFO_STANDARD) {
 488                 FIND_FILE_STANDARD_INFO *pfData;
 489                 pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 490
 491                 new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 492                                 pfData->FileNameLength;
 493         } else {
 494                 u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
 495
 496                 if (old_entry + next_offset < old_entry) {
 497                         cifs_dbg(VFS, "Invalid offset %u\n", next_offset);
 498                         return NULL;
 499                 }
 500                 new_entry = old_entry + next_offset;
 501         }
 502         cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
 503         /* validate that new_entry is not past end of SMB */
 504         if (new_entry >= end_of_smb) {
 505                 cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
 506                          new_entry, end_of_smb, old_entry);
 507                 return NULL;
 508         } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 509                     (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 510                   || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 511                    (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 512                 cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
 513                          new_entry, end_of_smb);
 514                 return NULL;
 515         } else
 516                 return new_entry;
 517
 518 }
 519
 520 struct cifs_dirent {
 521         const char      *name;
 522         size_t          namelen;
 523         u32             resume_key;
 524         u64             ino;
 525 };
 526
 527 static void cifs_fill_dirent_posix(struct cifs_dirent *de,
 528                                    const struct smb2_posix_info *info)
 529 {
 530         struct smb2_posix_info_parsed parsed;
 531
 532         /* payload should have already been checked at this point */
 533         if (posix_info_parse(info, NULL, &parsed) < 0) {
 534                 cifs_dbg(VFS, "Invalid POSIX info payload\n");
 535                 return;
 536         }
 537
 538         de->name = parsed.name;
 539         de->namelen = parsed.name_len;
 540         de->resume_key = info->Ignored;
 541         de->ino = le64_to_cpu(info->Inode);
 542 }
 543
 544 static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 545                 const FILE_UNIX_INFO *info, bool is_unicode)
 546 {
 547         de->name = &info->FileName[0];
 548         if (is_unicode)
 549                 de->namelen = cifs_unicode_bytelen(de->name);
 550         else
 551                 de->namelen = strnlen(de->name, PATH_MAX);
 552         de->resume_key = info->ResumeKey;
 553         de->ino = le64_to_cpu(info->basic.UniqueId);
 554 }
 555
 556 static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 557                 const FILE_DIRECTORY_INFO *info)
 558 {
 559         de->name = &info->FileName[0];
 560         de->namelen = le32_to_cpu(info->FileNameLength);
 561         de->resume_key = info->FileIndex;
 562 }
 563
 564 static void cifs_fill_dirent_full(struct cifs_dirent *de,
 565                 const FILE_FULL_DIRECTORY_INFO *info)
 566 {
 567         de->name = &info->FileName[0];
 568         de->namelen = le32_to_cpu(info->FileNameLength);
 569         de->resume_key = info->FileIndex;
 570 }
 571
 572 static void cifs_fill_dirent_search(struct cifs_dirent *de,
 573                 const SEARCH_ID_FULL_DIR_INFO *info)
 574 {
 575         de->name = &info->FileName[0];
 576         de->namelen = le32_to_cpu(info->FileNameLength);
 577         de->resume_key = info->FileIndex;
 578         de->ino = le64_to_cpu(info->UniqueId);
 579 }
 580
 581 static void cifs_fill_dirent_both(struct cifs_dirent *de,
 582                 const FILE_BOTH_DIRECTORY_INFO *info)
 583 {
 584         de->name = &info->FileName[0];
 585         de->namelen = le32_to_cpu(info->FileNameLength);
 586         de->resume_key = info->FileIndex;
 587 }
 588
 589 static void cifs_fill_dirent_std(struct cifs_dirent *de,
 590                 const FIND_FILE_STANDARD_INFO *info)
 591 {
 592         de->name = &info->FileName[0];
 593         /* one byte length, no endianess conversion */
 594         de->namelen = info->FileNameLength;
 595         de->resume_key = info->ResumeKey;
 596 }
 597
 598 static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 599                 u16 level, bool is_unicode)
 600 {
 601         memset(de, 0, sizeof(*de));
 602
 603         switch (level) {
 604         case SMB_FIND_FILE_POSIX_INFO:
 605                 cifs_fill_dirent_posix(de, info);
 606                 break;
 607         case SMB_FIND_FILE_UNIX:
 608                 cifs_fill_dirent_unix(de, info, is_unicode);
 609                 break;
 610         case SMB_FIND_FILE_DIRECTORY_INFO:
 611                 cifs_fill_dirent_dir(de, info);
 612                 break;
 613         case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 614                 cifs_fill_dirent_full(de, info);
 615                 break;
 616         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 617                 cifs_fill_dirent_search(de, info);
 618                 break;
 619         case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 620                 cifs_fill_dirent_both(de, info);
 621                 break;
 622         case SMB_FIND_FILE_INFO_STANDARD:
 623                 cifs_fill_dirent_std(de, info);
 624                 break;
 625         default:
 626                 cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
 627                 return -EINVAL;
 628         }
 629
 630         return 0;
 631 }
 632
 633 #define UNICODE_DOT cpu_to_le16(0x2e)
 634
 635 /* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 636 static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 637 {
 638         int rc = 0;
 639
 640         if (!de->name)
 641                 return 0;
 642
 643         if (is_unicode) {
 644                 __le16 *ufilename = (__le16 *)de->name;
 645                 if (de->namelen == 2) {
 646                         /* check for . */
 647                         if (ufilename[0] == UNICODE_DOT)
 648                                 rc = 1;
 649                 } else if (de->namelen == 4) {
 650                         /* check for .. */
 651                         if (ufilename[0] == UNICODE_DOT &&
 652                             ufilename[1] == UNICODE_DOT)
 653                                 rc = 2;
 654                 }
 655         } else /* ASCII */ {
 656                 if (de->namelen == 1) {
 657                         if (de->name[0] == '.')
 658                                 rc = 1;
 659                 } else if (de->namelen == 2) {
 660                         if (de->name[0] == '.' && de->name[1] == '.')
 661                                 rc = 2;
 662                 }
 663         }
 664
 665         return rc;
 666 }
 667
 668 /* Check if directory that we are searching has changed so we can decide
 669    whether we can use the cached search results from the previous search */
 670 static int is_dir_changed(struct file *file)
 671 {
 672         struct inode *inode = file_inode(file);
 673         struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 674
 675         if (cifsInfo->time == 0)
 676                 return 1; /* directory was changed, perhaps due to unlink */
 677         else
 678                 return 0;
 679
 680 }
 681
 682 static int cifs_save_resume_key(const char *current_entry,
 683         struct cifsFileInfo *file_info)
 684 {
 685         struct cifs_dirent de;
 686         int rc;
 687
 688         rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 689                               file_info->srch_inf.unicode);
 690         if (!rc) {
 691                 file_info->srch_inf.presume_name = de.name;
 692                 file_info->srch_inf.resume_name_len = de.namelen;
 693                 file_info->srch_inf.resume_key = de.resume_key;
 694         }
 695         return rc;
 696 }
 697
 698 /*
 699  * Find the corresponding entry in the search. Note that the SMB server returns
 700  * search entries for . and .. which complicates logic here if we choose to
 701  * parse for them and we do not assume that they are located in the findfirst
 702  * return buffer. We start counting in the buffer with entry 2 and increment for
 703  * every entry (do not increment for . or .. entry).
 704  */
 705 static int
 706 find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
 707                 struct file *file, char *full_path,
 708                 char **current_entry, int *num_to_ret)
 709 {
 710         __u16 search_flags;
 711         int rc = 0;
 712         int pos_in_buf = 0;
 713         loff_t first_entry_in_buffer;
 714         loff_t index_to_find = pos;
 715         struct cifsFileInfo *cfile = file->private_data;
 716         struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
 717         struct TCP_Server_Info *server = tcon->ses->server;
 718         /* check if index in the buffer */
 719
 720         if (!server->ops->query_dir_first || !server->ops->query_dir_next)
 721                 return -ENOSYS;
 722
 723         if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
 724                 return -ENOENT;
 725
 726         *current_entry = NULL;
 727         first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
 728                                         cfile->srch_inf.entries_in_buffer;
 729
 730         /*
 731          * If first entry in buf is zero then is first buffer
 732          * in search response data which means it is likely . and ..
 733          * will be in this buffer, although some servers do not return
 734          * . and .. for the root of a drive and for those we need
 735          * to start two entries earlier.
 736          */
 737
 738         dump_cifs_file_struct(file, "In fce ");
 739         if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
 740              is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
 741                 /* close and restart search */
 742                 cifs_dbg(FYI, "search backing up - close and restart search\n");
 743                 spin_lock(&cfile->file_info_lock);
 744                 if (server->ops->dir_needs_close(cfile)) {
 745                         cfile->invalidHandle = true;
 746                         spin_unlock(&cfile->file_info_lock);
 747                         if (server->ops->close_dir)
 748                                 server->ops->close_dir(xid, tcon, &cfile->fid);
 749                 } else
 750                         spin_unlock(&cfile->file_info_lock);
 751                 if (cfile->srch_inf.ntwrk_buf_start) {
 752                         cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
 753                         if (cfile->srch_inf.smallBuf)
 754                                 cifs_small_buf_release(cfile->srch_inf.
 755                                                 ntwrk_buf_start);
 756                         else
 757                                 cifs_buf_release(cfile->srch_inf.
 758                                                 ntwrk_buf_start);
 759                         cfile->srch_inf.ntwrk_buf_start = NULL;
 760                 }
 761                 rc = initiate_cifs_search(xid, file, full_path);
 762                 if (rc) {
 763                         cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
 764                                  rc);
 765                         return rc;
 766                 }
 767                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 768                 if (cfile->srch_inf.last_entry)
 769                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 770         }
 771
 772         search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 773         if (backup_cred(cifs_sb))
 774                 search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 775
 776         while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
 777                (rc == 0) && !cfile->srch_inf.endOfSearch) {
 778                 cifs_dbg(FYI, "calling findnext2\n");
 779                 rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
 780                                                  search_flags,
 781                                                  &cfile->srch_inf);
 782                 /* FindFirst/Next set last_entry to NULL on malformed reply */
 783                 if (cfile->srch_inf.last_entry)
 784                         cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
 785                 if (rc)
 786                         return -ENOENT;
 787         }
 788         if (index_to_find < cfile->srch_inf.index_of_last_entry) {
 789                 /* we found the buffer that contains the entry */
 790                 /* scan and find it */
 791                 int i;
 792                 char *cur_ent;
 793                 char *end_of_smb;
 794
 795                 if (cfile->srch_inf.ntwrk_buf_start == NULL) {
 796                         cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
 797                         return -EIO;
 798                 }
 799
 800                 end_of_smb = cfile->srch_inf.ntwrk_buf_start +
 801                         server->ops->calc_smb_size(
 802                                         cfile->srch_inf.ntwrk_buf_start,
 803                                         server);
 804
 805                 cur_ent = cfile->srch_inf.srch_entries_start;
 806                 first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
 807                                         - cfile->srch_inf.entries_in_buffer;
 808                 pos_in_buf = index_to_find - first_entry_in_buffer;
 809                 cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
 810
 811                 for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
 812                         /* go entry by entry figuring out which is first */
 813                         cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
 814                                                 cfile->srch_inf.info_level);
 815                 }
 816                 if ((cur_ent == NULL) && (i < pos_in_buf)) {
 817                         /* BB fixme - check if we should flag this error */
 818                         cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
 819                                  pos_in_buf, index_to_find, rc);
 820                 }
 821                 rc = 0;
 822                 *current_entry = cur_ent;
 823         } else {
 824                 cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
 825                 return 0;
 826         }
 827
 828         if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
 829                 cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
 830                 *num_to_ret = 0;
 831         } else
 832                 *num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
 833
 834         return rc;
 835 }
 836
 837 static int cifs_filldir(char *find_entry, struct file *file,
 838                 struct dir_context *ctx,
 839                 char *scratch_buf, unsigned int max_len)
 840 {
 841         struct cifsFileInfo *file_info = file->private_data;
 842         struct super_block *sb = file_inode(file)->i_sb;
 843         struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 844         struct cifs_dirent de = { NULL, };
 845         struct cifs_fattr fattr;
 846         struct qstr name;
 847         int rc = 0;
 848         ino_t ino;
 849
 850         rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 851                               file_info->srch_inf.unicode);
 852         if (rc)
 853                 return rc;
 854
 855         if (de.namelen > max_len) {
 856                 cifs_dbg(VFS, "bad search response length %zd past smb end\n",
 857                          de.namelen);
 858                 return -EINVAL;
 859         }
 860
 861         /* skip . and .. since we added them first */
 862         if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 863                 return 0;
 864
 865         if (file_info->srch_inf.unicode) {
 866                 struct nls_table *nlt = cifs_sb->local_nls;
 867                 int map_type;
 868
 869                 map_type = cifs_remap(cifs_sb);
 870                 name.name = scratch_buf;
 871                 name.len =
 872                         cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 873                                         UNICODE_NAME_MAX,
 874                                         min_t(size_t, de.namelen,
 875                                               (size_t)max_len), nlt, map_type);
 876                 name.len -= nls_nullsize(nlt);
 877         } else {
 878                 name.name = de.name;
 879                 name.len = de.namelen;
 880         }
 881
 882         switch (file_info->srch_inf.info_level) {
 883         case SMB_FIND_FILE_POSIX_INFO:
 884                 cifs_posix_to_fattr(&fattr,
 885                                     (struct smb2_posix_info *)find_entry,
 886                                     cifs_sb);
 887                 break;
 888         case SMB_FIND_FILE_UNIX:
 889                 cifs_unix_basic_to_fattr(&fattr,
 890                                          &((FILE_UNIX_INFO *)find_entry)->basic,
 891                                          cifs_sb);
 892                 break;
 893         case SMB_FIND_FILE_INFO_STANDARD:
 894                 cifs_std_info_to_fattr(&fattr,
 895                                        (FIND_FILE_STANDARD_INFO *)find_entry,
 896                                        cifs_sb);
 897                 break;
 898         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 899                 cifs_fulldir_info_to_fattr(&fattr,
 900                                            (SEARCH_ID_FULL_DIR_INFO *)find_entry,
 901                                            cifs_sb);
 902                 break;
 903         default:
 904                 cifs_dir_info_to_fattr(&fattr,
 905                                        (FILE_DIRECTORY_INFO *)find_entry,
 906                                        cifs_sb);
 907                 break;
 908         }
 909
 910         if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 911                 fattr.cf_uniqueid = de.ino;
 912         } else {
 913                 fattr.cf_uniqueid = iunique(sb, ROOT_I);
 914                 cifs_autodisable_serverino(cifs_sb);
 915         }
 916
 917         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 918             couldbe_mf_symlink(&fattr))
 919                 /*
 920                  * trying to get the type and mode can be slow,
 921                  * so just call those regular files for now, and mark
 922                  * for reval
 923                  */
 924                 fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 925
 926         cifs_prime_dcache(file_dentry(file), &name, &fattr);
 927
 928         ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 929         return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
 930 }
 931
 932
 933 int cifs_readdir(struct file *file, struct dir_context *ctx)
 934 {
 935         int rc = 0;
 936         unsigned int xid;
 937         int i;
 938         struct cifs_tcon *tcon;
 939         struct cifsFileInfo *cifsFile = NULL;
 940         char *current_entry;
 941         int num_to_fill = 0;
 942         char *tmp_buf = NULL;
 943         char *end_of_smb;
 944         unsigned int max_len;
 945         char *full_path = NULL;
 946
 947         xid = get_xid();
 948
 949         full_path = build_path_from_dentry(file_dentry(file));
 950         if (full_path == NULL) {
 951                 rc = -ENOMEM;
 952                 goto rddir2_exit;
 953         }
 954
 955         /*
 956          * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 957          * '..'. Otherwise we won't be able to notify VFS in case of failure.
 958          */
 959         if (file->private_data == NULL) {
 960                 rc = initiate_cifs_search(xid, file, full_path);
 961                 cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
 962                 if (rc)
 963                         goto rddir2_exit;
 964         }
 965
 966         if (!dir_emit_dots(file, ctx))
 967                 goto rddir2_exit;
 968
 969         /* 1) If search is active,
 970                 is in current search buffer?
 971                 if it before then restart search
 972                 if after then keep searching till find it */
 973
 974         cifsFile = file->private_data;
 975         if (cifsFile->srch_inf.endOfSearch) {
 976                 if (cifsFile->srch_inf.emptyDir) {
 977                         cifs_dbg(FYI, "End of search, empty dir\n");
 978                         rc = 0;
 979                         goto rddir2_exit;
 980                 }
 981         } /* else {
 982                 cifsFile->invalidHandle = true;
 983                 tcon->ses->server->close(xid, tcon, &cifsFile->fid);
 984         } */
 985
 986         tcon = tlink_tcon(cifsFile->tlink);
 987         rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path,
 988                              &current_entry, &num_to_fill);
 989         if (rc) {
 990                 cifs_dbg(FYI, "fce error %d\n", rc);
 991                 goto rddir2_exit;
 992         } else if (current_entry != NULL) {
 993                 cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
 994         } else {
 995                 cifs_dbg(FYI, "Could not find entry\n");
 996                 goto rddir2_exit;
 997         }
 998         cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
 999                  num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
1000         max_len = tcon->ses->server->ops->calc_smb_size(
1001                         cifsFile->srch_inf.ntwrk_buf_start,
1002                         tcon->ses->server);
1003         end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
1004
1005         tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
1006         if (tmp_buf == NULL) {
1007                 rc = -ENOMEM;
1008                 goto rddir2_exit;
1009         }
1010
1011         for (i = 0; i < num_to_fill; i++) {
1012                 if (current_entry == NULL) {
1013                         /* evaluate whether this case is an error */
1014                         cifs_dbg(VFS, "past SMB end,  num to fill %d i %d\n",
1015                                  num_to_fill, i);
1016                         break;
1017                 }
1018                 /*
1019                  * if buggy server returns . and .. late do we want to
1020                  * check for that here?
1021                  */
1022                 *tmp_buf = 0;
1023                 rc = cifs_filldir(current_entry, file, ctx,
1024                                   tmp_buf, max_len);
1025                 if (rc) {
1026                         if (rc > 0)
1027                                 rc = 0;
1028                         break;
1029                 }
1030
1031                 ctx->pos++;
1032                 if (ctx->pos ==
1033                         cifsFile->srch_inf.index_of_last_entry) {
1034                         cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
1035                                  ctx->pos, tmp_buf);
1036                         cifs_save_resume_key(current_entry, cifsFile);
1037                         break;
1038                 } else
1039                         current_entry =
1040                                 nxt_dir_entry(current_entry, end_of_smb,
1041                                         cifsFile->srch_inf.info_level);
1042         }
1043         kfree(tmp_buf);
1044
1045 rddir2_exit:
1046         kfree(full_path);
1047         free_xid(xid);
1048         return rc;
1049 }