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