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