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
  36/*
  37 * To be safe - for UCS to UTF-8 with strings loaded with the rare long
  38 * characters alloc more to account for such multibyte target UTF-8
  39 * characters.
  40 */
  41#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
  42
  43#ifdef CONFIG_CIFS_DEBUG2
  44static void dump_cifs_file_struct(struct file *file, char *label)
  45{
  46        struct cifsFileInfo *cf;
  47
  48        if (file) {
  49                cf = file->private_data;
  50                if (cf == NULL) {
  51                        cFYI(1, "empty cifs private file data");
  52                        return;
  53                }
  54                if (cf->invalidHandle)
  55                        cFYI(1, "invalid handle");
  56                if (cf->srch_inf.endOfSearch)
  57                        cFYI(1, "end of search");
  58                if (cf->srch_inf.emptyDir)
  59                        cFYI(1, "empty dir");
  60        }
  61}
  62#else
  63static inline void dump_cifs_file_struct(struct file *file, char *label)
  64{
  65}
  66#endif /* DEBUG2 */
  67
  68/*
  69 * Find the dentry that matches "name". If there isn't one, create one. If it's
  70 * a negative dentry or the uniqueid changed, then drop it and recreate it.
  71 */
  72static struct dentry *
  73cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
  74                    struct cifs_fattr *fattr)
  75{
  76        struct dentry *dentry, *alias;
  77        struct inode *inode;
  78        struct super_block *sb = parent->d_inode->i_sb;
  79
  80        cFYI(1, "For %s", name->name);
  81
  82        if (parent->d_op && parent->d_op->d_hash)
  83                parent->d_op->d_hash(parent, parent->d_inode, name);
  84        else
  85                name->hash = full_name_hash(name->name, name->len);
  86
  87        dentry = d_lookup(parent, name);
  88        if (dentry) {
  89                inode = dentry->d_inode;
  90                /* update inode in place if i_ino didn't change */
  91                if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
  92                        cifs_fattr_to_inode(inode, fattr);
  93                        return dentry;
  94                }
  95                d_drop(dentry);
  96                dput(dentry);
  97        }
  98
  99        dentry = d_alloc(parent, name);
 100        if (dentry == NULL)
 101                return NULL;
 102
 103        inode = cifs_iget(sb, fattr);
 104        if (!inode) {
 105                dput(dentry);
 106                return NULL;
 107        }
 108
 109        alias = d_materialise_unique(dentry, inode);
 110        if (alias != NULL) {
 111                dput(dentry);
 112                if (IS_ERR(alias))
 113                        return NULL;
 114                dentry = alias;
 115        }
 116
 117        return dentry;
 118}
 119
 120static void
 121cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
 122{
 123        fattr->cf_uid = cifs_sb->mnt_uid;
 124        fattr->cf_gid = cifs_sb->mnt_gid;
 125
 126        if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
 127                fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
 128                fattr->cf_dtype = DT_DIR;
 129        } else {
 130                fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
 131                fattr->cf_dtype = DT_REG;
 132        }
 133
 134        if (fattr->cf_cifsattrs & ATTR_READONLY)
 135                fattr->cf_mode &= ~S_IWUGO;
 136
 137        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
 138            fattr->cf_cifsattrs & ATTR_SYSTEM) {
 139                if (fattr->cf_eof == 0)  {
 140                        fattr->cf_mode &= ~S_IFMT;
 141                        fattr->cf_mode |= S_IFIFO;
 142                        fattr->cf_dtype = DT_FIFO;
 143                } else {
 144                        /*
 145                         * trying to get the type and mode via SFU can be slow,
 146                         * so just call those regular files for now, and mark
 147                         * for reval
 148                         */
 149                        fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
 150                }
 151        }
 152}
 153
 154static void
 155cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
 156                       struct cifs_sb_info *cifs_sb)
 157{
 158        memset(fattr, 0, sizeof(*fattr));
 159        fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
 160        fattr->cf_eof = le64_to_cpu(info->EndOfFile);
 161        fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
 162        fattr->cf_createtime = le64_to_cpu(info->CreationTime);
 163        fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
 164        fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 165        fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
 166
 167        cifs_fill_common_info(fattr, cifs_sb);
 168}
 169
 170static void
 171cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
 172                       struct cifs_sb_info *cifs_sb)
 173{
 174        int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
 175
 176        memset(fattr, 0, sizeof(*fattr));
 177        fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
 178                                            info->LastAccessTime, offset);
 179        fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
 180                                            info->LastWriteTime, offset);
 181        fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
 182                                            info->LastWriteTime, offset);
 183
 184        fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
 185        fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
 186        fattr->cf_eof = le32_to_cpu(info->DataSize);
 187
 188        cifs_fill_common_info(fattr, cifs_sb);
 189}
 190
 191/* BB eventually need to add the following helper function to
 192      resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
 193      we try to do FindFirst on (NTFS) directory symlinks */
 194/*
 195int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
 196                             unsigned int xid)
 197{
 198        __u16 fid;
 199        int len;
 200        int oplock = 0;
 201        int rc;
 202        struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
 203        char *tmpbuffer;
 204
 205        rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
 206                        OPEN_REPARSE_POINT, &fid, &oplock, NULL,
 207                        cifs_sb->local_nls,
 208                        cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 209        if (!rc) {
 210                tmpbuffer = kmalloc(maxpath);
 211                rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
 212                                tmpbuffer,
 213                                maxpath -1,
 214                                fid,
 215                                cifs_sb->local_nls);
 216                if (CIFSSMBClose(xid, ptcon, fid)) {
 217                        cFYI(1, "Error closing temporary reparsepoint open");
 218                }
 219        }
 220}
 221 */
 222
 223static int initiate_cifs_search(const unsigned int xid, struct file *file)
 224{
 225        __u16 search_flags;
 226        int rc = 0;
 227        char *full_path = NULL;
 228        struct cifsFileInfo *cifsFile;
 229        struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 230        struct tcon_link *tlink = NULL;
 231        struct cifs_tcon *tcon;
 232
 233        if (file->private_data == NULL) {
 234                tlink = cifs_sb_tlink(cifs_sb);
 235                if (IS_ERR(tlink))
 236                        return PTR_ERR(tlink);
 237
 238                cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
 239                if (cifsFile == NULL) {
 240                        rc = -ENOMEM;
 241                        goto error_exit;
 242                }
 243                file->private_data = cifsFile;
 244                cifsFile->tlink = cifs_get_tlink(tlink);
 245                tcon = tlink_tcon(tlink);
 246        } else {
 247                cifsFile = file->private_data;
 248                tcon = tlink_tcon(cifsFile->tlink);
 249        }
 250
 251        cifsFile->invalidHandle = true;
 252        cifsFile->srch_inf.endOfSearch = false;
 253
 254        full_path = build_path_from_dentry(file->f_path.dentry);
 255        if (full_path == NULL) {
 256                rc = -ENOMEM;
 257                goto error_exit;
 258        }
 259
 260        cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);
 261
 262ffirst_retry:
 263        /* test for Unix extensions */
 264        /* but now check for them on the share/mount not on the SMB session */
 265        /* if (cap_unix(tcon->ses) { */
 266        if (tcon->unix_ext)
 267                cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
 268        else if ((tcon->ses->capabilities &
 269                  tcon->ses->server->vals->cap_nt_find) == 0) {
 270                cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
 271        } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 272                cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
 273        } else /* not srvinos - BB fixme add check for backlevel? */ {
 274                cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
 275        }
 276
 277        search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 278        if (backup_cred(cifs_sb))
 279                search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 280
 281        rc = CIFSFindFirst(xid, tcon, full_path, cifs_sb->local_nls,
 282                &cifsFile->netfid, search_flags, &cifsFile->srch_inf,
 283                cifs_sb->mnt_cifs_flags &
 284                        CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
 285        if (rc == 0)
 286                cifsFile->invalidHandle = false;
 287        /* BB add following call to handle readdir on new NTFS symlink errors
 288        else if STATUS_STOPPED_ON_SYMLINK
 289                call get_symlink_reparse_path and retry with new path */
 290        else if ((rc == -EOPNOTSUPP) &&
 291                (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 292                cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
 293                goto ffirst_retry;
 294        }
 295error_exit:
 296        kfree(full_path);
 297        cifs_put_tlink(tlink);
 298        return rc;
 299}
 300
 301/* return length of unicode string in bytes */
 302static int cifs_unicode_bytelen(const char *str)
 303{
 304        int len;
 305        const __le16 *ustr = (const __le16 *)str;
 306
 307        for (len = 0; len <= PATH_MAX; len++) {
 308                if (ustr[len] == 0)
 309                        return len << 1;
 310        }
 311        cFYI(1, "Unicode string longer than PATH_MAX found");
 312        return len << 1;
 313}
 314
 315static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
 316{
 317        char *new_entry;
 318        FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
 319
 320        if (level == SMB_FIND_FILE_INFO_STANDARD) {
 321                FIND_FILE_STANDARD_INFO *pfData;
 322                pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
 323
 324                new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
 325                                pfData->FileNameLength;
 326        } else
 327                new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
 328        cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
 329        /* validate that new_entry is not past end of SMB */
 330        if (new_entry >= end_of_smb) {
 331                cERROR(1, "search entry %p began after end of SMB %p old entry %p",
 332                        new_entry, end_of_smb, old_entry);
 333                return NULL;
 334        } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
 335                    (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
 336                  || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
 337                   (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
 338                cERROR(1, "search entry %p extends after end of SMB %p",
 339                        new_entry, end_of_smb);
 340                return NULL;
 341        } else
 342                return new_entry;
 343
 344}
 345
 346struct cifs_dirent {
 347        const char      *name;
 348        size_t          namelen;
 349        u32             resume_key;
 350        u64             ino;
 351};
 352
 353static void cifs_fill_dirent_unix(struct cifs_dirent *de,
 354                const FILE_UNIX_INFO *info, bool is_unicode)
 355{
 356        de->name = &info->FileName[0];
 357        if (is_unicode)
 358                de->namelen = cifs_unicode_bytelen(de->name);
 359        else
 360                de->namelen = strnlen(de->name, PATH_MAX);
 361        de->resume_key = info->ResumeKey;
 362        de->ino = le64_to_cpu(info->basic.UniqueId);
 363}
 364
 365static void cifs_fill_dirent_dir(struct cifs_dirent *de,
 366                const FILE_DIRECTORY_INFO *info)
 367{
 368        de->name = &info->FileName[0];
 369        de->namelen = le32_to_cpu(info->FileNameLength);
 370        de->resume_key = info->FileIndex;
 371}
 372
 373static void cifs_fill_dirent_full(struct cifs_dirent *de,
 374                const FILE_FULL_DIRECTORY_INFO *info)
 375{
 376        de->name = &info->FileName[0];
 377        de->namelen = le32_to_cpu(info->FileNameLength);
 378        de->resume_key = info->FileIndex;
 379}
 380
 381static void cifs_fill_dirent_search(struct cifs_dirent *de,
 382                const SEARCH_ID_FULL_DIR_INFO *info)
 383{
 384        de->name = &info->FileName[0];
 385        de->namelen = le32_to_cpu(info->FileNameLength);
 386        de->resume_key = info->FileIndex;
 387        de->ino = le64_to_cpu(info->UniqueId);
 388}
 389
 390static void cifs_fill_dirent_both(struct cifs_dirent *de,
 391                const FILE_BOTH_DIRECTORY_INFO *info)
 392{
 393        de->name = &info->FileName[0];
 394        de->namelen = le32_to_cpu(info->FileNameLength);
 395        de->resume_key = info->FileIndex;
 396}
 397
 398static void cifs_fill_dirent_std(struct cifs_dirent *de,
 399                const FIND_FILE_STANDARD_INFO *info)
 400{
 401        de->name = &info->FileName[0];
 402        /* one byte length, no endianess conversion */
 403        de->namelen = info->FileNameLength;
 404        de->resume_key = info->ResumeKey;
 405}
 406
 407static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
 408                u16 level, bool is_unicode)
 409{
 410        memset(de, 0, sizeof(*de));
 411
 412        switch (level) {
 413        case SMB_FIND_FILE_UNIX:
 414                cifs_fill_dirent_unix(de, info, is_unicode);
 415                break;
 416        case SMB_FIND_FILE_DIRECTORY_INFO:
 417                cifs_fill_dirent_dir(de, info);
 418                break;
 419        case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
 420                cifs_fill_dirent_full(de, info);
 421                break;
 422        case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 423                cifs_fill_dirent_search(de, info);
 424                break;
 425        case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
 426                cifs_fill_dirent_both(de, info);
 427                break;
 428        case SMB_FIND_FILE_INFO_STANDARD:
 429                cifs_fill_dirent_std(de, info);
 430                break;
 431        default:
 432                cFYI(1, "Unknown findfirst level %d", level);
 433                return -EINVAL;
 434        }
 435
 436        return 0;
 437}
 438
 439#define UNICODE_DOT cpu_to_le16(0x2e)
 440
 441/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
 442static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
 443{
 444        int rc = 0;
 445
 446        if (!de->name)
 447                return 0;
 448
 449        if (is_unicode) {
 450                __le16 *ufilename = (__le16 *)de->name;
 451                if (de->namelen == 2) {
 452                        /* check for . */
 453                        if (ufilename[0] == UNICODE_DOT)
 454                                rc = 1;
 455                } else if (de->namelen == 4) {
 456                        /* check for .. */
 457                        if (ufilename[0] == UNICODE_DOT &&
 458                            ufilename[1] == UNICODE_DOT)
 459                                rc = 2;
 460                }
 461        } else /* ASCII */ {
 462                if (de->namelen == 1) {
 463                        if (de->name[0] == '.')
 464                                rc = 1;
 465                } else if (de->namelen == 2) {
 466                        if (de->name[0] == '.' && de->name[1] == '.')
 467                                rc = 2;
 468                }
 469        }
 470
 471        return rc;
 472}
 473
 474/* Check if directory that we are searching has changed so we can decide
 475   whether we can use the cached search results from the previous search */
 476static int is_dir_changed(struct file *file)
 477{
 478        struct inode *inode = file->f_path.dentry->d_inode;
 479        struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
 480
 481        if (cifsInfo->time == 0)
 482                return 1; /* directory was changed, perhaps due to unlink */
 483        else
 484                return 0;
 485
 486}
 487
 488static int cifs_save_resume_key(const char *current_entry,
 489        struct cifsFileInfo *file_info)
 490{
 491        struct cifs_dirent de;
 492        int rc;
 493
 494        rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
 495                              file_info->srch_inf.unicode);
 496        if (!rc) {
 497                file_info->srch_inf.presume_name = de.name;
 498                file_info->srch_inf.resume_name_len = de.namelen;
 499                file_info->srch_inf.resume_key = de.resume_key;
 500        }
 501        return rc;
 502}
 503
 504/* find the corresponding entry in the search */
 505/* Note that the SMB server returns search entries for . and .. which
 506   complicates logic here if we choose to parse for them and we do not
 507   assume that they are located in the findfirst return buffer.*/
 508/* We start counting in the buffer with entry 2 and increment for every
 509   entry (do not increment for . or .. entry) */
 510static int find_cifs_entry(const unsigned int xid, struct cifs_tcon *pTcon,
 511        struct file *file, char **ppCurrentEntry, int *num_to_ret)
 512{
 513        __u16 search_flags;
 514        int rc = 0;
 515        int pos_in_buf = 0;
 516        loff_t first_entry_in_buffer;
 517        loff_t index_to_find = file->f_pos;
 518        struct cifsFileInfo *cifsFile = file->private_data;
 519        struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
 520        /* check if index in the buffer */
 521
 522        if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
 523           (num_to_ret == NULL))
 524                return -ENOENT;
 525
 526        *ppCurrentEntry = NULL;
 527        first_entry_in_buffer =
 528                cifsFile->srch_inf.index_of_last_entry -
 529                        cifsFile->srch_inf.entries_in_buffer;
 530
 531        /* if first entry in buf is zero then is first buffer
 532        in search response data which means it is likely . and ..
 533        will be in this buffer, although some servers do not return
 534        . and .. for the root of a drive and for those we need
 535        to start two entries earlier */
 536
 537        dump_cifs_file_struct(file, "In fce ");
 538        if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
 539             is_dir_changed(file)) ||
 540           (index_to_find < first_entry_in_buffer)) {
 541                /* close and restart search */
 542                cFYI(1, "search backing up - close and restart search");
 543                spin_lock(&cifs_file_list_lock);
 544                if (!cifsFile->srch_inf.endOfSearch &&
 545                    !cifsFile->invalidHandle) {
 546                        cifsFile->invalidHandle = true;
 547                        spin_unlock(&cifs_file_list_lock);
 548                        CIFSFindClose(xid, pTcon, cifsFile->netfid);
 549                } else
 550                        spin_unlock(&cifs_file_list_lock);
 551                if (cifsFile->srch_inf.ntwrk_buf_start) {
 552                        cFYI(1, "freeing SMB ff cache buf on search rewind");
 553                        if (cifsFile->srch_inf.smallBuf)
 554                                cifs_small_buf_release(cifsFile->srch_inf.
 555                                                ntwrk_buf_start);
 556                        else
 557                                cifs_buf_release(cifsFile->srch_inf.
 558                                                ntwrk_buf_start);
 559                        cifsFile->srch_inf.ntwrk_buf_start = NULL;
 560                }
 561                rc = initiate_cifs_search(xid, file);
 562                if (rc) {
 563                        cFYI(1, "error %d reinitiating a search on rewind",
 564                                 rc);
 565                        return rc;
 566                }
 567                /* FindFirst/Next set last_entry to NULL on malformed reply */
 568                if (cifsFile->srch_inf.last_entry)
 569                        cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 570                                                cifsFile);
 571        }
 572
 573        search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
 574        if (backup_cred(cifs_sb))
 575                search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
 576
 577        while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
 578              (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
 579                cFYI(1, "calling findnext2");
 580                rc = CIFSFindNext(xid, pTcon, cifsFile->netfid, search_flags,
 581                                  &cifsFile->srch_inf);
 582                /* FindFirst/Next set last_entry to NULL on malformed reply */
 583                if (cifsFile->srch_inf.last_entry)
 584                        cifs_save_resume_key(cifsFile->srch_inf.last_entry,
 585                                                cifsFile);
 586                if (rc)
 587                        return -ENOENT;
 588        }
 589        if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
 590                /* we found the buffer that contains the entry */
 591                /* scan and find it */
 592                int i;
 593                char *current_entry;
 594                char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
 595                        smbCalcSize((struct smb_hdr *)
 596                                cifsFile->srch_inf.ntwrk_buf_start);
 597
 598                current_entry = cifsFile->srch_inf.srch_entries_start;
 599                first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
 600                                        - cifsFile->srch_inf.entries_in_buffer;
 601                pos_in_buf = index_to_find - first_entry_in_buffer;
 602                cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
 603
 604                for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
 605                        /* go entry by entry figuring out which is first */
 606                        current_entry = nxt_dir_entry(current_entry, end_of_smb,
 607                                                cifsFile->srch_inf.info_level);
 608                }
 609                if ((current_entry == NULL) && (i < pos_in_buf)) {
 610                        /* BB fixme - check if we should flag this error */
 611                        cERROR(1, "reached end of buf searching for pos in buf"
 612                          " %d index to find %lld rc %d",
 613                          pos_in_buf, index_to_find, rc);
 614                }
 615                rc = 0;
 616                *ppCurrentEntry = current_entry;
 617        } else {
 618                cFYI(1, "index not in buffer - could not findnext into it");
 619                return 0;
 620        }
 621
 622        if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
 623                cFYI(1, "can not return entries pos_in_buf beyond last");
 624                *num_to_ret = 0;
 625        } else
 626                *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
 627
 628        return rc;
 629}
 630
 631static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
 632                void *dirent, char *scratch_buf, unsigned int max_len)
 633{
 634        struct cifsFileInfo *file_info = file->private_data;
 635        struct super_block *sb = file->f_path.dentry->d_sb;
 636        struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
 637        struct cifs_dirent de = { NULL, };
 638        struct cifs_fattr fattr;
 639        struct dentry *dentry;
 640        struct qstr name;
 641        int rc = 0;
 642        ino_t ino;
 643
 644        rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
 645                              file_info->srch_inf.unicode);
 646        if (rc)
 647                return rc;
 648
 649        if (de.namelen > max_len) {
 650                cERROR(1, "bad search response length %zd past smb end",
 651                          de.namelen);
 652                return -EINVAL;
 653        }
 654
 655        /* skip . and .. since we added them first */
 656        if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
 657                return 0;
 658
 659        if (file_info->srch_inf.unicode) {
 660                struct nls_table *nlt = cifs_sb->local_nls;
 661
 662                name.name = scratch_buf;
 663                name.len =
 664                        cifs_from_utf16((char *)name.name, (__le16 *)de.name,
 665                                        UNICODE_NAME_MAX,
 666                                        min_t(size_t, de.namelen,
 667                                              (size_t)max_len), nlt,
 668                                        cifs_sb->mnt_cifs_flags &
 669                                                CIFS_MOUNT_MAP_SPECIAL_CHR);
 670                name.len -= nls_nullsize(nlt);
 671        } else {
 672                name.name = de.name;
 673                name.len = de.namelen;
 674        }
 675
 676        switch (file_info->srch_inf.info_level) {
 677        case SMB_FIND_FILE_UNIX:
 678                cifs_unix_basic_to_fattr(&fattr,
 679                                         &((FILE_UNIX_INFO *)find_entry)->basic,
 680                                         cifs_sb);
 681                break;
 682        case SMB_FIND_FILE_INFO_STANDARD:
 683                cifs_std_info_to_fattr(&fattr,
 684                                       (FIND_FILE_STANDARD_INFO *)find_entry,
 685                                       cifs_sb);
 686                break;
 687        default:
 688                cifs_dir_info_to_fattr(&fattr,
 689                                       (FILE_DIRECTORY_INFO *)find_entry,
 690                                       cifs_sb);
 691                break;
 692        }
 693
 694        if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
 695                fattr.cf_uniqueid = de.ino;
 696        } else {
 697                fattr.cf_uniqueid = iunique(sb, ROOT_I);
 698                cifs_autodisable_serverino(cifs_sb);
 699        }
 700
 701        if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
 702            CIFSCouldBeMFSymlink(&fattr))
 703                /*
 704                 * trying to get the type and mode can be slow,
 705                 * so just call those regular files for now, and mark
 706                 * for reval
 707                 */
 708                fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
 709
 710        ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
 711        dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
 712
 713        rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
 714                     fattr.cf_dtype);
 715
 716        dput(dentry);
 717        return rc;
 718}
 719
 720
 721int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
 722{
 723        int rc = 0;
 724        unsigned int xid;
 725        int i;
 726        struct cifs_tcon *pTcon;
 727        struct cifsFileInfo *cifsFile = NULL;
 728        char *current_entry;
 729        int num_to_fill = 0;
 730        char *tmp_buf = NULL;
 731        char *end_of_smb;
 732        unsigned int max_len;
 733
 734        xid = get_xid();
 735
 736        /*
 737         * Ensure FindFirst doesn't fail before doing filldir() for '.' and
 738         * '..'. Otherwise we won't be able to notify VFS in case of failure.
 739         */
 740        if (file->private_data == NULL) {
 741                rc = initiate_cifs_search(xid, file);
 742                cFYI(1, "initiate cifs search rc %d", rc);
 743                if (rc)
 744                        goto rddir2_exit;
 745        }
 746
 747        switch ((int) file->f_pos) {
 748        case 0:
 749                if (filldir(direntry, ".", 1, file->f_pos,
 750                     file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
 751                        cERROR(1, "Filldir for current dir failed");
 752                        rc = -ENOMEM;
 753                        break;
 754                }
 755                file->f_pos++;
 756        case 1:
 757                if (filldir(direntry, "..", 2, file->f_pos,
 758                     parent_ino(file->f_path.dentry), DT_DIR) < 0) {
 759                        cERROR(1, "Filldir for parent dir failed");
 760                        rc = -ENOMEM;
 761                        break;
 762                }
 763                file->f_pos++;
 764        default:
 765                /* 1) If search is active,
 766                        is in current search buffer?
 767                        if it before then restart search
 768                        if after then keep searching till find it */
 769
 770                if (file->private_data == NULL) {
 771                        rc = -EINVAL;
 772                        free_xid(xid);
 773                        return rc;
 774                }
 775                cifsFile = file->private_data;
 776                if (cifsFile->srch_inf.endOfSearch) {
 777                        if (cifsFile->srch_inf.emptyDir) {
 778                                cFYI(1, "End of search, empty dir");
 779                                rc = 0;
 780                                break;
 781                        }
 782                } /* else {
 783                        cifsFile->invalidHandle = true;
 784                        CIFSFindClose(xid, pTcon, cifsFile->netfid);
 785                } */
 786
 787                pTcon = tlink_tcon(cifsFile->tlink);
 788                rc = find_cifs_entry(xid, pTcon, file,
 789                                &current_entry, &num_to_fill);
 790                if (rc) {
 791                        cFYI(1, "fce error %d", rc);
 792                        goto rddir2_exit;
 793                } else if (current_entry != NULL) {
 794                        cFYI(1, "entry %lld found", file->f_pos);
 795                } else {
 796                        cFYI(1, "could not find entry");
 797                        goto rddir2_exit;
 798                }
 799                cFYI(1, "loop through %d times filling dir for net buf %p",
 800                        num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
 801                max_len = smbCalcSize((struct smb_hdr *)
 802                                cifsFile->srch_inf.ntwrk_buf_start);
 803                end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
 804
 805                tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
 806                if (tmp_buf == NULL) {
 807                        rc = -ENOMEM;
 808                        break;
 809                }
 810
 811                for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
 812                        if (current_entry == NULL) {
 813                                /* evaluate whether this case is an error */
 814                                cERROR(1, "past SMB end,  num to fill %d i %d",
 815                                          num_to_fill, i);
 816                                break;
 817                        }
 818                        /* if buggy server returns . and .. late do
 819                        we want to check for that here? */
 820                        rc = cifs_filldir(current_entry, file,
 821                                        filldir, direntry, tmp_buf, max_len);
 822                        if (rc == -EOVERFLOW) {
 823                                rc = 0;
 824                                break;
 825                        }
 826
 827                        file->f_pos++;
 828                        if (file->f_pos ==
 829                                cifsFile->srch_inf.index_of_last_entry) {
 830                                cFYI(1, "last entry in buf at pos %lld %s",
 831                                        file->f_pos, tmp_buf);
 832                                cifs_save_resume_key(current_entry, cifsFile);
 833                                break;
 834                        } else
 835                                current_entry =
 836                                        nxt_dir_entry(current_entry, end_of_smb,
 837                                                cifsFile->srch_inf.info_level);
 838                }
 839                kfree(tmp_buf);
 840                break;
 841        } /* end switch */
 842
 843rddir2_exit:
 844        free_xid(xid);
 845        return rc;
 846}
 847
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