/*
 *   fs/cifs/readdir.c
 *
 *   Directory search handling
 *
 *   Copyright (C) International Business Machines  Corp., 2004, 2008
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifsfs.h"

/*
 * To be safe - for UCS to UTF-8 with strings loaded with the rare long
 * characters alloc more to account for such multibyte target UTF-8
 * characters.
 */
#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)

#ifdef CONFIG_CIFS_DEBUG2
static void dump_cifs_file_struct(struct file *file, char *label)
{
        struct cifsFileInfo *cf;

        if (file) {
                cf = file->private_data;
                if (cf == NULL) {
                        cFYI(1, "empty cifs private file data");
                        return;
                }
                if (cf->invalidHandle)
                        cFYI(1, "invalid handle");
                if (cf->srch_inf.endOfSearch)
                        cFYI(1, "end of search");
                if (cf->srch_inf.emptyDir)
                        cFYI(1, "empty dir");
        }
}
#else
static inline void dump_cifs_file_struct(struct file *file, char *label)
{
}
#endif /* DEBUG2 */

/*
 * Find the dentry that matches "name". If there isn't one, create one. If it's
 * a negative dentry or the uniqueid changed, then drop it and recreate it.
 */
static struct dentry *
cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
                    struct cifs_fattr *fattr)
{
        struct dentry *dentry, *alias;
        struct inode *inode;
        struct super_block *sb = parent->d_inode->i_sb;

        cFYI(1, "For %s", name->name);

        if (parent->d_op && parent->d_op->d_hash)
                parent->d_op->d_hash(parent, name);
        else
                name->hash = full_name_hash(name->name, name->len);

        dentry = d_lookup(parent, name);
        if (dentry) {
                /* FIXME: check for inode number changes? */
                if (dentry->d_inode != NULL)
                        return dentry;
                d_drop(dentry);
                dput(dentry);
        }

        dentry = d_alloc(parent, name);
        if (dentry == NULL)
                return NULL;

        inode = cifs_iget(sb, fattr);
        if (!inode) {
                dput(dentry);
                return NULL;
        }

        if (CIFS_SB(sb)->tcon->nocase)
                dentry->d_op = &cifs_ci_dentry_ops;
        else
                dentry->d_op = &cifs_dentry_ops;

        alias = d_materialise_unique(dentry, inode);
        if (alias != NULL) {
                dput(dentry);
                if (IS_ERR(alias))
                        return NULL;
                dentry = alias;
        }

        return dentry;
}

static void
cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
{
        fattr->cf_uid = cifs_sb->mnt_uid;
        fattr->cf_gid = cifs_sb->mnt_gid;

        if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
                fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
                fattr->cf_dtype = DT_DIR;
        } else {
                fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
                fattr->cf_dtype = DT_REG;
        }

        if (fattr->cf_cifsattrs & ATTR_READONLY)
                fattr->cf_mode &= ~S_IWUGO;

        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
            fattr->cf_cifsattrs & ATTR_SYSTEM) {
                if (fattr->cf_eof == 0)  {
                        fattr->cf_mode &= ~S_IFMT;
                        fattr->cf_mode |= S_IFIFO;
                        fattr->cf_dtype = DT_FIFO;
                } else {
                        /*
                         * trying to get the type and mode via SFU can be slow,
                         * so just call those regular files for now, and mark
                         * for reval
                         */
                        fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
                }
        }
}

static void
cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
                       struct cifs_sb_info *cifs_sb)
{
        memset(fattr, 0, sizeof(*fattr));
        fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
        fattr->cf_eof = le64_to_cpu(info->EndOfFile);
        fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
        fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
        fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
        fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);

        cifs_fill_common_info(fattr, cifs_sb);
}

static void
cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
                       struct cifs_sb_info *cifs_sb)
{
        int offset = cifs_sb->tcon->ses->server->timeAdj;

        memset(fattr, 0, sizeof(*fattr));
        fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
                                            info->LastAccessTime, offset);
        fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
                                            info->LastWriteTime, offset);
        fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
                                            info->LastWriteTime, offset);

        fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
        fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
        fattr->cf_eof = le32_to_cpu(info->DataSize);

        cifs_fill_common_info(fattr, cifs_sb);
}

/* BB eventually need to add the following helper function to
      resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
      we try to do FindFirst on (NTFS) directory symlinks */
/*
int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
                             int xid)
{
        __u16 fid;
        int len;
        int oplock = 0;
        int rc;
        struct cifsTconInfo *ptcon = cifs_sb->tcon;
        char *tmpbuffer;

        rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
                        OPEN_REPARSE_POINT, &fid, &oplock, NULL,
                        cifs_sb->local_nls,
                        cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
        if (!rc) {
                tmpbuffer = kmalloc(maxpath);
                rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
                                tmpbuffer,
                                maxpath -1,
                                fid,
                                cifs_sb->local_nls);
                if (CIFSSMBClose(xid, ptcon, fid)) {
                        cFYI(1, "Error closing temporary reparsepoint open");
                }
        }
}
 */

static int initiate_cifs_search(const int xid, struct file *file)
{
        int rc = 0;
        char *full_path;
        struct cifsFileInfo *cifsFile;
        struct cifs_sb_info *cifs_sb;
        struct cifsTconInfo *pTcon;

        if (file->private_data == NULL) {
                file->private_data =
                        kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
        }

        if (file->private_data == NULL)
                return -ENOMEM;
        cifsFile = file->private_data;
        cifsFile->invalidHandle = true;
        cifsFile->srch_inf.endOfSearch = false;

        cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
        if (cifs_sb == NULL)
                return -EINVAL;

        pTcon = cifs_sb->tcon;
        if (pTcon == NULL)
                return -EINVAL;

        full_path = build_path_from_dentry(file->f_path.dentry);

        if (full_path == NULL)
                return -ENOMEM;

        cFYI(1, "Full path: %s start at: %lld", full_path, file->f_pos);

ffirst_retry:
        /* test for Unix extensions */
        /* but now check for them on the share/mount not on the SMB session */
/*      if (pTcon->ses->capabilities & CAP_UNIX) { */
        if (pTcon->unix_ext)
                cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
        else if ((pTcon->ses->capabilities &
                        (CAP_NT_SMBS | CAP_NT_FIND)) == 0) {
                cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
        } else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
                cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
        } else /* not srvinos - BB fixme add check for backlevel? */ {
                cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
        }

        rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
                &cifsFile->netfid, &cifsFile->srch_inf,
                cifs_sb->mnt_cifs_flags &
                        CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
        if (rc == 0)
                cifsFile->invalidHandle = false;
        /* BB add following call to handle readdir on new NTFS symlink errors
        else if STATUS_STOPPED_ON_SYMLINK
                call get_symlink_reparse_path and retry with new path */
        else if ((rc == -EOPNOTSUPP) &&
                (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
                cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
                goto ffirst_retry;
        }
        kfree(full_path);
        return rc;
}

/* return length of unicode string in bytes */
static int cifs_unicode_bytelen(char *str)
{
        int len;
        __le16 *ustr = (__le16 *)str;

        for (len = 0; len <= PATH_MAX; len++) {
                if (ustr[len] == 0)
                        return len << 1;
        }
        cFYI(1, "Unicode string longer than PATH_MAX found");
        return len << 1;
}

static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
{
        char *new_entry;
        FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;

        if (level == SMB_FIND_FILE_INFO_STANDARD) {
                FIND_FILE_STANDARD_INFO *pfData;
                pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;

                new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
                                pfData->FileNameLength;
        } else
                new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
        cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
        /* validate that new_entry is not past end of SMB */
        if (new_entry >= end_of_smb) {
                cERROR(1, "search entry %p began after end of SMB %p old entry %p",
                        new_entry, end_of_smb, old_entry);
                return NULL;
        } else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
                    (new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
                  || ((level != SMB_FIND_FILE_INFO_STANDARD) &&
                   (new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb)))  {
                cERROR(1, "search entry %p extends after end of SMB %p",
                        new_entry, end_of_smb);
                return NULL;
        } else
                return new_entry;

}

#define UNICODE_DOT cpu_to_le16(0x2e)

/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
static int cifs_entry_is_dot(char *current_entry, struct cifsFileInfo *cfile)
{
        int rc = 0;
        char *filename = NULL;
        int len = 0;

        if (cfile->srch_inf.info_level == SMB_FIND_FILE_UNIX) {
                FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                if (cfile->srch_inf.unicode) {
                        len = cifs_unicode_bytelen(filename);
                } else {
                        /* BB should we make this strnlen of PATH_MAX? */
                        len = strnlen(filename, 5);
                }
        } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_DIRECTORY_INFO) {
                FILE_DIRECTORY_INFO *pFindData =
                        (FILE_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
        } else if (cfile->srch_inf.info_level ==
                        SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
                FILE_FULL_DIRECTORY_INFO *pFindData =
                        (FILE_FULL_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
        } else if (cfile->srch_inf.info_level ==
                        SMB_FIND_FILE_ID_FULL_DIR_INFO) {
                SEARCH_ID_FULL_DIR_INFO *pFindData =
                        (SEARCH_ID_FULL_DIR_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
        } else if (cfile->srch_inf.info_level ==
                        SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
                FILE_BOTH_DIRECTORY_INFO *pFindData =
                        (FILE_BOTH_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
        } else if (cfile->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD) {
                FIND_FILE_STANDARD_INFO *pFindData =
                        (FIND_FILE_STANDARD_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = pFindData->FileNameLength;
        } else {
                cFYI(1, "Unknown findfirst level %d",
                         cfile->srch_inf.info_level);
        }

        if (filename) {
                if (cfile->srch_inf.unicode) {
                        __le16 *ufilename = (__le16 *)filename;
                        if (len == 2) {
                                /* check for . */
                                if (ufilename[0] == UNICODE_DOT)
                                        rc = 1;
                        } else if (len == 4) {
                                /* check for .. */
                                if ((ufilename[0] == UNICODE_DOT)
                                   && (ufilename[1] == UNICODE_DOT))
                                        rc = 2;
                        }
                } else /* ASCII */ {
                        if (len == 1) {
                                if (filename[0] == '.')
                                        rc = 1;
                        } else if (len == 2) {
                                if ((filename[0] == '.') && (filename[1] == '.'))
                                        rc = 2;
                        }
                }
        }

        return rc;
}

/* Check if directory that we are searching has changed so we can decide
   whether we can use the cached search results from the previous search */
static int is_dir_changed(struct file *file)
{
        struct inode *inode = file->f_path.dentry->d_inode;
        struct cifsInodeInfo *cifsInfo = CIFS_I(inode);

        if (cifsInfo->time == 0)
                return 1; /* directory was changed, perhaps due to unlink */
        else
                return 0;

}

static int cifs_save_resume_key(const char *current_entry,
        struct cifsFileInfo *cifsFile)
{
        int rc = 0;
        unsigned int len = 0;
        __u16 level;
        char *filename;

        if ((cifsFile == NULL) || (current_entry == NULL))
                return -EINVAL;

        level = cifsFile->srch_inf.info_level;

        if (level == SMB_FIND_FILE_UNIX) {
                FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;

                filename = &pFindData->FileName[0];
                if (cifsFile->srch_inf.unicode) {
                        len = cifs_unicode_bytelen(filename);
                } else {
                        /* BB should we make this strnlen of PATH_MAX? */
                        len = strnlen(filename, PATH_MAX);
                }
                cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
        } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
                FILE_DIRECTORY_INFO *pFindData =
                        (FILE_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
                cifsFile->srch_inf.resume_key = pFindData->FileIndex;
        } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
                FILE_FULL_DIRECTORY_INFO *pFindData =
                        (FILE_FULL_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
                cifsFile->srch_inf.resume_key = pFindData->FileIndex;
        } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
                SEARCH_ID_FULL_DIR_INFO *pFindData =
                        (SEARCH_ID_FULL_DIR_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
                cifsFile->srch_inf.resume_key = pFindData->FileIndex;
        } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
                FILE_BOTH_DIRECTORY_INFO *pFindData =
                        (FILE_BOTH_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
                cifsFile->srch_inf.resume_key = pFindData->FileIndex;
        } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
                FIND_FILE_STANDARD_INFO *pFindData =
                        (FIND_FILE_STANDARD_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                /* one byte length, no name conversion */
                len = (unsigned int)pFindData->FileNameLength;
                cifsFile->srch_inf.resume_key = pFindData->ResumeKey;
        } else {
                cFYI(1, "Unknown findfirst level %d", level);
                return -EINVAL;
        }
        cifsFile->srch_inf.resume_name_len = len;
        cifsFile->srch_inf.presume_name = filename;
        return rc;
}

/* find the corresponding entry in the search */
/* Note that the SMB server returns search entries for . and .. which
   complicates logic here if we choose to parse for them and we do not
   assume that they are located in the findfirst return buffer.*/
/* We start counting in the buffer with entry 2 and increment for every
   entry (do not increment for . or .. entry) */
static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
        struct file *file, char **ppCurrentEntry, int *num_to_ret)
{
        int rc = 0;
        int pos_in_buf = 0;
        loff_t first_entry_in_buffer;
        loff_t index_to_find = file->f_pos;
        struct cifsFileInfo *cifsFile = file->private_data;
        /* check if index in the buffer */

        if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
           (num_to_ret == NULL))
                return -ENOENT;

        *ppCurrentEntry = NULL;
        first_entry_in_buffer =
                cifsFile->srch_inf.index_of_last_entry -
                        cifsFile->srch_inf.entries_in_buffer;

        /* if first entry in buf is zero then is first buffer
        in search response data which means it is likely . and ..
        will be in this buffer, although some servers do not return
        . and .. for the root of a drive and for those we need
        to start two entries earlier */

        dump_cifs_file_struct(file, "In fce ");
        if (((index_to_find < cifsFile->srch_inf.index_of_last_entry) &&
             is_dir_changed(file)) ||
           (index_to_find < first_entry_in_buffer)) {
                /* close and restart search */
                cFYI(1, "search backing up - close and restart search");
                write_lock(&GlobalSMBSeslock);
                if (!cifsFile->srch_inf.endOfSearch &&
                    !cifsFile->invalidHandle) {
                        cifsFile->invalidHandle = true;
                        write_unlock(&GlobalSMBSeslock);
                        CIFSFindClose(xid, pTcon, cifsFile->netfid);
                } else
                        write_unlock(&GlobalSMBSeslock);
                if (cifsFile->srch_inf.ntwrk_buf_start) {
                        cFYI(1, "freeing SMB ff cache buf on search rewind");
                        if (cifsFile->srch_inf.smallBuf)
                                cifs_small_buf_release(cifsFile->srch_inf.
                                                ntwrk_buf_start);
                        else
                                cifs_buf_release(cifsFile->srch_inf.
                                                ntwrk_buf_start);
                        cifsFile->srch_inf.ntwrk_buf_start = NULL;
                }
                rc = initiate_cifs_search(xid, file);
                if (rc) {
                        cFYI(1, "error %d reinitiating a search on rewind",
                                 rc);
                        return rc;
                }
                cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
        }

        while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
              (rc == 0) && !cifsFile->srch_inf.endOfSearch) {
                cFYI(1, "calling findnext2");
                rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
                                  &cifsFile->srch_inf);
                cifs_save_resume_key(cifsFile->srch_inf.last_entry, cifsFile);
                if (rc)
                        return -ENOENT;
        }
        if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
                /* we found the buffer that contains the entry */
                /* scan and find it */
                int i;
                char *current_entry;
                char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
                        smbCalcSize((struct smb_hdr *)
                                cifsFile->srch_inf.ntwrk_buf_start);

                current_entry = cifsFile->srch_inf.srch_entries_start;
                first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
                                        - cifsFile->srch_inf.entries_in_buffer;
                pos_in_buf = index_to_find - first_entry_in_buffer;
                cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);

                for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
                        /* go entry by entry figuring out which is first */
                        current_entry = nxt_dir_entry(current_entry, end_of_smb,
                                                cifsFile->srch_inf.info_level);
                }
                if ((current_entry == NULL) && (i < pos_in_buf)) {
                        /* BB fixme - check if we should flag this error */
                        cERROR(1, "reached end of buf searching for pos in buf"
                          " %d index to find %lld rc %d",
                          pos_in_buf, index_to_find, rc);
                }
                rc = 0;
                *ppCurrentEntry = current_entry;
        } else {
                cFYI(1, "index not in buffer - could not findnext into it");
                return 0;
        }

        if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
                cFYI(1, "can not return entries pos_in_buf beyond last");
                *num_to_ret = 0;
        } else
                *num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;

        return rc;
}

/* inode num, inode type and filename returned */
static int cifs_get_name_from_search_buf(struct qstr *pqst,
        char *current_entry, __u16 level, unsigned int unicode,
        struct cifs_sb_info *cifs_sb, unsigned int max_len, __u64 *pinum)
{
        int rc = 0;
        unsigned int len = 0;
        char *filename;
        struct nls_table *nlt = cifs_sb->local_nls;

        *pinum = 0;

        if (level == SMB_FIND_FILE_UNIX) {
                FILE_UNIX_INFO *pFindData = (FILE_UNIX_INFO *)current_entry;

                filename = &pFindData->FileName[0];
                if (unicode) {
                        len = cifs_unicode_bytelen(filename);
                } else {
                        /* BB should we make this strnlen of PATH_MAX? */
                        len = strnlen(filename, PATH_MAX);
                }

                *pinum = le64_to_cpu(pFindData->basic.UniqueId);
        } else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
                FILE_DIRECTORY_INFO *pFindData =
                        (FILE_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
        } else if (level == SMB_FIND_FILE_FULL_DIRECTORY_INFO) {
                FILE_FULL_DIRECTORY_INFO *pFindData =
                        (FILE_FULL_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
        } else if (level == SMB_FIND_FILE_ID_FULL_DIR_INFO) {
                SEARCH_ID_FULL_DIR_INFO *pFindData =
                        (SEARCH_ID_FULL_DIR_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
                *pinum = le64_to_cpu(pFindData->UniqueId);
        } else if (level == SMB_FIND_FILE_BOTH_DIRECTORY_INFO) {
                FILE_BOTH_DIRECTORY_INFO *pFindData =
                        (FILE_BOTH_DIRECTORY_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                len = le32_to_cpu(pFindData->FileNameLength);
        } else if (level == SMB_FIND_FILE_INFO_STANDARD) {
                FIND_FILE_STANDARD_INFO *pFindData =
                        (FIND_FILE_STANDARD_INFO *)current_entry;
                filename = &pFindData->FileName[0];
                /* one byte length, no name conversion */
                len = (unsigned int)pFindData->FileNameLength;
        } else {
                cFYI(1, "Unknown findfirst level %d", level);
                return -EINVAL;
        }

        if (len > max_len) {
                cERROR(1, "bad search response length %d past smb end", len);
                return -EINVAL;
        }

        if (unicode) {
                pqst->len = cifs_from_ucs2((char *) pqst->name,
                                           (__le16 *) filename,
                                           UNICODE_NAME_MAX,
                                           min(len, max_len), nlt,
                                           cifs_sb->mnt_cifs_flags &
                                                CIFS_MOUNT_MAP_SPECIAL_CHR);
                pqst->len -= nls_nullsize(nlt);
        } else {
                pqst->name = filename;
                pqst->len = len;
        }
        return rc;
}

static int cifs_filldir(char *pfindEntry, struct file *file, filldir_t filldir,
                        void *direntry, char *scratch_buf, unsigned int max_len)
{
        int rc = 0;
        struct qstr qstring;
        struct cifsFileInfo *pCifsF;
        u64    inum;
        ino_t  ino;
        struct super_block *sb;
        struct cifs_sb_info *cifs_sb;
        struct dentry *tmp_dentry;
        struct cifs_fattr fattr;

        /* get filename and len into qstring */
        /* get dentry */
        /* decide whether to create and populate ionde */
        if ((direntry == NULL) || (file == NULL))
                return -EINVAL;

        pCifsF = file->private_data;

        if ((scratch_buf == NULL) || (pfindEntry == NULL) || (pCifsF == NULL))
                return -ENOENT;

        rc = cifs_entry_is_dot(pfindEntry, pCifsF);
        /* skip . and .. since we added them first */
        if (rc != 0)
                return 0;

        sb = file->f_path.dentry->d_sb;
        cifs_sb = CIFS_SB(sb);

        qstring.name = scratch_buf;
        rc = cifs_get_name_from_search_buf(&qstring, pfindEntry,
                        pCifsF->srch_inf.info_level,
                        pCifsF->srch_inf.unicode, cifs_sb,
                        max_len, &inum /* returned */);

        if (rc)
                return rc;

        if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX)
                cifs_unix_basic_to_fattr(&fattr,
                                 &((FILE_UNIX_INFO *) pfindEntry)->basic,
                                 cifs_sb);
        else if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_INFO_STANDARD)
                cifs_std_info_to_fattr(&fattr, (FIND_FILE_STANDARD_INFO *)
                                        pfindEntry, cifs_sb);
        else
                cifs_dir_info_to_fattr(&fattr, (FILE_DIRECTORY_INFO *)
                                        pfindEntry, cifs_sb);

        if (inum && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
                fattr.cf_uniqueid = inum;
        } else {
                fattr.cf_uniqueid = iunique(sb, ROOT_I);
                cifs_autodisable_serverino(cifs_sb);
        }

        ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
        tmp_dentry = cifs_readdir_lookup(file->f_dentry, &qstring, &fattr);

        rc = filldir(direntry, qstring.name, qstring.len, file->f_pos,
                     ino, fattr.cf_dtype);

        /*
         * we can not return filldir errors to the caller since they are
         * "normal" when the stat blocksize is too small - we return remapped
         * error instead
         *
         * FIXME: This looks bogus. filldir returns -EOVERFLOW in the above
         * case already. Why should we be clobbering other errors from it?
         */
        if (rc) {
                cFYI(1, "filldir rc = %d", rc);
                rc = -EOVERFLOW;
        }
        dput(tmp_dentry);
        return rc;
}


int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
{
        int rc = 0;
        int xid, i;
        struct cifs_sb_info *cifs_sb;
        struct cifsTconInfo *pTcon;
        struct cifsFileInfo *cifsFile = NULL;
        char *current_entry;
        int num_to_fill = 0;
        char *tmp_buf = NULL;
        char *end_of_smb;
        unsigned int max_len;

        xid = GetXid();

        cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
        pTcon = cifs_sb->tcon;
        if (pTcon == NULL)
                return -EINVAL;

        switch ((int) file->f_pos) {
        case 0:
                if (filldir(direntry, ".", 1, file->f_pos,
                     file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
                        cERROR(1, "Filldir for current dir failed");
                        rc = -ENOMEM;
                        break;
                }
                file->f_pos++;
        case 1:
                if (filldir(direntry, "..", 2, file->f_pos,
                     file->f_path.dentry->d_parent->d_inode->i_ino, DT_DIR) < 0) {
                        cERROR(1, "Filldir for parent dir failed");
                        rc = -ENOMEM;
                        break;
                }
                file->f_pos++;
        default:
                /* 1) If search is active,
                        is in current search buffer?
                        if it before then restart search
                        if after then keep searching till find it */

                if (file->private_data == NULL) {
                        rc = initiate_cifs_search(xid, file);
                        cFYI(1, "initiate cifs search rc %d", rc);
                        if (rc) {
                                FreeXid(xid);
                                return rc;
                        }
                }
                if (file->private_data == NULL) {
                        rc = -EINVAL;
                        FreeXid(xid);
                        return rc;
                }
                cifsFile = file->private_data;
                if (cifsFile->srch_inf.endOfSearch) {
                        if (cifsFile->srch_inf.emptyDir) {
                                cFYI(1, "End of search, empty dir");
                                rc = 0;
                                break;
                        }
                } /* else {
                        cifsFile->invalidHandle = true;
                        CIFSFindClose(xid, pTcon, cifsFile->netfid);
                } */

                rc = find_cifs_entry(xid, pTcon, file,
                                &current_entry, &num_to_fill);
                if (rc) {
                        cFYI(1, "fce error %d", rc);
                        goto rddir2_exit;
                } else if (current_entry != NULL) {
                        cFYI(1, "entry %lld found", file->f_pos);
                } else {
                        cFYI(1, "could not find entry");
                        goto rddir2_exit;
                }
                cFYI(1, "loop through %d times filling dir for net buf %p",
                        num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
                max_len = smbCalcSize((struct smb_hdr *)
                                cifsFile->srch_inf.ntwrk_buf_start);
                end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;

                tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
                if (tmp_buf == NULL) {
                        rc = -ENOMEM;
                        break;
                }

                for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
                        if (current_entry == NULL) {
                                /* evaluate whether this case is an error */
                                cERROR(1, "past SMB end,  num to fill %d i %d",
                                          num_to_fill, i);
                                break;
                        }
                        /* if buggy server returns . and .. late do
                        we want to check for that here? */
                        rc = cifs_filldir(current_entry, file,
                                        filldir, direntry, tmp_buf, max_len);
                        if (rc == -EOVERFLOW) {
                                rc = 0;
                                break;
                        }

                        file->f_pos++;
                        if (file->f_pos ==
                                cifsFile->srch_inf.index_of_last_entry) {
                                cFYI(1, "last entry in buf at pos %lld %s",
                                        file->f_pos, tmp_buf);
                                cifs_save_resume_key(current_entry, cifsFile);
                                break;
                        } else
                                current_entry =
                                        nxt_dir_entry(current_entry, end_of_smb,
                                                cifsFile->srch_inf.info_level);
                }
                kfree(tmp_buf);
                break;
        } /* end switch */

rddir2_exit:
        FreeXid(xid);
        return rc;
}