/*
 * NTDLL directory functions
 *
 * Copyright 1993 Erik Bos
 * Copyright 2003 Eric Pouech
 * Copyright 1996, 2004 Alexandre Julliard
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "config.h"
#include "wine/port.h"

#include <assert.h>
#include <sys/types.h>
#ifdef HAVE_DIRENT_H
# include <dirent.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#ifdef HAVE_MNTENT_H
#include <mntent.h>
#endif
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#ifdef HAVE_SYS_SYSCALL_H
# include <sys/syscall.h>
#endif
#ifdef HAVE_SYS_ATTR_H
#include <sys/attr.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_LINUX_IOCTL_H
#include <linux/ioctl.h>
#endif
#ifdef HAVE_LINUX_MAJOR_H
# include <linux/major.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_MOUNT_H
#include <sys/mount.h>
#endif
#ifdef HAVE_SYS_STATFS_H
#include <sys/statfs.h>
#endif
#include <time.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#define NONAMELESSUNION
#define NONAMELESSSTRUCT
#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "windef.h"
#include "winnt.h"
#include "winternl.h"
#include "ddk/wdm.h"
#include "ntdll_misc.h"
#include "wine/unicode.h"
#include "wine/server.h"
#include "wine/list.h"
#include "wine/library.h"
#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(file);

/* just in case... */
#undef VFAT_IOCTL_READDIR_BOTH
#undef USE_GETDENTS

#ifdef linux

/* We want the real kernel dirent structure, not the libc one */
typedef struct
{
    long d_ino;
    long d_off;
    unsigned short d_reclen;
    char d_name[256];
} KERNEL_DIRENT;

/* Define the VFAT ioctl to get both short and long file names */
#define VFAT_IOCTL_READDIR_BOTH  _IOR('r', 1, KERNEL_DIRENT [2] )

#ifndef O_DIRECTORY
# define O_DIRECTORY 0200000 /* must be directory */
#endif

#ifdef __NR_getdents64
typedef struct
{
    ULONG64        d_ino;
    LONG64         d_off;
    unsigned short d_reclen;
    unsigned char  d_type;
    char           d_name[256];
} KERNEL_DIRENT64;

static inline int getdents64( int fd, char *de, unsigned int size )
{
    return syscall( __NR_getdents64, fd, de, size );
}
#define USE_GETDENTS
#endif

#endif  /* linux */

#define IS_OPTION_TRUE(ch) ((ch) == 'y' || (ch) == 'Y' || (ch) == 't' || (ch) == 'T' || (ch) == '1')
#define IS_SEPARATOR(ch)   ((ch) == '\\' || (ch) == '/')

#define INVALID_NT_CHARS   '*','?','<','>','|','"'
#define INVALID_DOS_CHARS  INVALID_NT_CHARS,'+','=',',',';','[',']',' ','\345'

#define MAX_DIR_ENTRY_LEN 255  /* max length of a directory entry in chars */

#define MAX_IGNORED_FILES 4

struct file_identity
{
    dev_t dev;
    ino_t ino;
};

static struct file_identity ignored_files[MAX_IGNORED_FILES];
static unsigned int ignored_files_count;

union file_directory_info
{
    ULONG                              next;
    FILE_DIRECTORY_INFORMATION         dir;
    FILE_BOTH_DIRECTORY_INFORMATION    both;
    FILE_FULL_DIRECTORY_INFORMATION    full;
    FILE_ID_BOTH_DIRECTORY_INFORMATION id_both;
    FILE_ID_FULL_DIRECTORY_INFORMATION id_full;
};

static BOOL show_dot_files;
static RTL_RUN_ONCE init_once = RTL_RUN_ONCE_INIT;

/* at some point we may want to allow Winelib apps to set this */
static const BOOL is_case_sensitive = FALSE;

UNICODE_STRING system_dir = { 0, 0, NULL };  /* system directory */

static struct file_identity curdir;
static struct file_identity windir;

static RTL_CRITICAL_SECTION dir_section;
static RTL_CRITICAL_SECTION_DEBUG critsect_debug =
{
    0, 0, &dir_section,
    { &critsect_debug.ProcessLocksList, &critsect_debug.ProcessLocksList },
      0, 0, { (DWORD_PTR)(__FILE__ ": dir_section") }
};
static RTL_CRITICAL_SECTION dir_section = { &critsect_debug, -1, 0, 0, 0, 0 };


/* check if a given Unicode char is OK in a DOS short name */
static inline BOOL is_invalid_dos_char( WCHAR ch )
{
    static const WCHAR invalid_chars[] = { INVALID_DOS_CHARS,'~','.',0 };
    if (ch > 0x7f) return TRUE;
    return strchrW( invalid_chars, ch ) != NULL;
}

/* check if the device can be a mounted volume */
static inline BOOL is_valid_mounted_device( const struct stat *st )
{
#if defined(linux) || defined(__sun__)
    return S_ISBLK( st->st_mode );
#else
    /* disks are char devices on *BSD */
    return S_ISCHR( st->st_mode );
#endif
}

static inline void ignore_file( const char *name )
{
    struct stat st;
    assert( ignored_files_count < MAX_IGNORED_FILES );
    if (!stat( name, &st ))
    {
        ignored_files[ignored_files_count].dev = st.st_dev;
        ignored_files[ignored_files_count].ino = st.st_ino;
        ignored_files_count++;
    }
}

static inline BOOL is_same_file( const struct file_identity *file, const struct stat *st )
{
    return st->st_dev == file->dev && st->st_ino == file->ino;
}

static inline BOOL is_ignored_file( const struct stat *st )
{
    unsigned int i;

    for (i = 0; i < ignored_files_count; i++)
        if (is_same_file( &ignored_files[i], st )) return TRUE;
    return FALSE;
}

static inline unsigned int dir_info_size( FILE_INFORMATION_CLASS class, unsigned int len )
{
    switch (class)
    {
    case FileDirectoryInformation:
        return (FIELD_OFFSET( FILE_DIRECTORY_INFORMATION, FileName[len] ) + 7) & ~7;
    case FileBothDirectoryInformation:
        return (FIELD_OFFSET( FILE_BOTH_DIRECTORY_INFORMATION, FileName[len] ) + 7) & ~7;
    case FileFullDirectoryInformation:
        return (FIELD_OFFSET( FILE_FULL_DIRECTORY_INFORMATION, FileName[len] ) + 7) & ~7;
    case FileIdBothDirectoryInformation:
        return (FIELD_OFFSET( FILE_ID_BOTH_DIRECTORY_INFORMATION, FileName[len] ) + 7) & ~7;
    case FileIdFullDirectoryInformation:
        return (FIELD_OFFSET( FILE_ID_FULL_DIRECTORY_INFORMATION, FileName[len] ) + 7) & ~7;
    default:
        assert(0);
        return 0;
    }
}

static inline unsigned int max_dir_info_size( FILE_INFORMATION_CLASS class )
{
    return dir_info_size( class, MAX_DIR_ENTRY_LEN );
}

static inline BOOL has_wildcard( const UNICODE_STRING *mask )
{
    return (!mask ||
            memchrW( mask->Buffer, '*', mask->Length / sizeof(WCHAR) ) ||
            memchrW( mask->Buffer, '?', mask->Length / sizeof(WCHAR) ));
}


/* support for a directory queue for filesystem searches */

struct dir_name
{
    struct list entry;
    char name[1];
};

static struct list dir_queue = LIST_INIT( dir_queue );

static NTSTATUS add_dir_to_queue( const char *name )
{
    int len = strlen( name ) + 1;
    struct dir_name *dir = RtlAllocateHeap( GetProcessHeap(), 0,
                                            FIELD_OFFSET( struct dir_name, name[len] ));
    if (!dir) return STATUS_NO_MEMORY;
    strcpy( dir->name, name );
    list_add_tail( &dir_queue, &dir->entry );
    return STATUS_SUCCESS;
}

static NTSTATUS next_dir_in_queue( char *name )
{
    struct list *head = list_head( &dir_queue );
    if (head)
    {
        struct dir_name *dir = LIST_ENTRY( head, struct dir_name, entry );
        strcpy( name, dir->name );
        list_remove( &dir->entry );
        RtlFreeHeap( GetProcessHeap(), 0, dir );
        return STATUS_SUCCESS;
    }
    return STATUS_OBJECT_NAME_NOT_FOUND;
}

static void flush_dir_queue(void)
{
    struct list *head;

    while ((head = list_head( &dir_queue )))
    {
        struct dir_name *dir = LIST_ENTRY( head, struct dir_name, entry );
        list_remove( &dir->entry );
        RtlFreeHeap( GetProcessHeap(), 0, dir );
    }
}


/***********************************************************************
 *           get_default_com_device
 *
 * Return the default device to use for serial ports.
 */
static char *get_default_com_device( int num )
{
    char *ret = NULL;

    if (!num || num > 9) return ret;
#ifdef linux
    ret = RtlAllocateHeap( GetProcessHeap(), 0, sizeof("/dev/ttyS0") );
    if (ret)
    {
        strcpy( ret, "/dev/ttyS0" );
        ret[strlen(ret) - 1] = '0' + num - 1;
    }
#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
    ret = RtlAllocateHeap( GetProcessHeap(), 0, sizeof("/dev/cuau0") );
    if (ret)
    {
        strcpy( ret, "/dev/cuau0" );
        ret[strlen(ret) - 1] = '0' + num - 1;
    }
#elif defined(__DragonFly__)
    ret = RtlAllocateHeap( GetProcessHeap(), 0, sizeof("/dev/cuaa0") );
    if (ret)
    {
        strcpy( ret, "/dev/cuaa0" );
        ret[strlen(ret) - 1] = '0' + num - 1;
    }
#else
    FIXME( "no known default for device com%d\n", num );
#endif
    return ret;
}


/***********************************************************************
 *           get_default_lpt_device
 *
 * Return the default device to use for parallel ports.
 */
static char *get_default_lpt_device( int num )
{
    char *ret = NULL;

    if (!num || num > 9) return ret;
#ifdef linux
    ret = RtlAllocateHeap( GetProcessHeap(), 0, sizeof("/dev/lp0") );
    if (ret)
    {
        strcpy( ret, "/dev/lp0" );
        ret[strlen(ret) - 1] = '0' + num - 1;
    }
#else
    FIXME( "no known default for device lpt%d\n", num );
#endif
    return ret;
}

#ifdef __ANDROID__

static char *unescape_field( char *str )
{
    char *in, *out;

    for (in = out = str; *in; in++, out++)
    {
        *out = *in;
        if (in[0] == '\\')
        {
            if (in[1] == '\\')
            {
                out[0] = '\\';
                in++;
            }
            else if (in[1] == '0' && in[2] == '4' && in[3] == '0')
            {
                out[0] = ' ';
                in += 3;
            }
            else if (in[1] == '0' && in[2] == '1' && in[3] == '1')
            {
                out[0] = '\t';
                in += 3;
            }
            else if (in[1] == '0' && in[2] == '1' && in[3] == '2')
            {
                out[0] = '\n';
                in += 3;
            }
            else if (in[1] == '1' && in[2] == '3' && in[3] == '4')
            {
                out[0] = '\\';
                in += 3;
            }
        }
    }
    *out = '\0';

    return str;
}

static inline char *get_field( char **str )
{
    char *ret;

    ret = strsep( str, " \t" );
    if (*str) *str += strspn( *str, " \t" );

    return ret;
}
/************************************************************************
 *                    getmntent_replacement
 *
 * getmntent replacement for Android.
 *
 * NB returned static buffer is not thread safe; protect with dir_section.
 */
static struct mntent *getmntent_replacement( FILE *f )
{
    static struct mntent entry;
    static char buf[4096];
    char *p, *start;

    do
    {
        if (!fgets( buf, sizeof(buf), f )) return NULL;
        p = strchr( buf, '\n' );
        if (p) *p = '\0';
        else /* Partially unread line, move file ptr to end */
        {
            char tmp[1024];
            while (fgets( tmp, sizeof(tmp), f ))
                if (strchr( tmp, '\n' )) break;
        }
        start = buf + strspn( buf, " \t" );
    } while (start[0] == '\0' || start[0] == '#');

    p = get_field( &start );
    entry.mnt_fsname = p ? unescape_field( p ) : (char *)"";

    p = get_field( &start );
    entry.mnt_dir = p ? unescape_field( p ) : (char *)"";

    p = get_field( &start );
    entry.mnt_type = p ? unescape_field( p ) : (char *)"";

    p = get_field( &start );
    entry.mnt_opts = p ? unescape_field( p ) : (char *)"";

    p = get_field( &start );
    entry.mnt_freq = p ? atoi(p) : 0;

    p = get_field( &start );
    entry.mnt_passno = p ? atoi(p) : 0;

    return &entry;
}
#define getmntent getmntent_replacement
#endif

/***********************************************************************
 *           DIR_get_drives_info
 *
 * Retrieve device/inode number for all the drives. Helper for find_drive_root.
 */
unsigned int DIR_get_drives_info( struct drive_info info[MAX_DOS_DRIVES] )
{
    static struct drive_info cache[MAX_DOS_DRIVES];
    static time_t last_update;
    static unsigned int nb_drives;
    unsigned int ret;
    time_t now = time(NULL);

    RtlEnterCriticalSection( &dir_section );
    if (now != last_update)
    {
        const char *config_dir = wine_get_config_dir();
        char *buffer, *p;
        struct stat st;
        unsigned int i;

        if ((buffer = RtlAllocateHeap( GetProcessHeap(), 0,
                                       strlen(config_dir) + sizeof("/dosdevices/a:") )))
        {
            strcpy( buffer, config_dir );
            strcat( buffer, "/dosdevices/a:" );
            p = buffer + strlen(buffer) - 2;

            for (i = nb_drives = 0; i < MAX_DOS_DRIVES; i++)
            {
                *p = 'a' + i;
                if (!stat( buffer, &st ))
                {
                    cache[i].dev = st.st_dev;
                    cache[i].ino = st.st_ino;
                    nb_drives++;
                }
                else
                {
                    cache[i].dev = 0;
                    cache[i].ino = 0;
                }
            }
            RtlFreeHeap( GetProcessHeap(), 0, buffer );
        }
        last_update = now;
    }
    memcpy( info, cache, sizeof(cache) );
    ret = nb_drives;
    RtlLeaveCriticalSection( &dir_section );
    return ret;
}


/***********************************************************************
 *           parse_mount_entries
 *
 * Parse mount entries looking for a given device. Helper for get_default_drive_device.
 */

#ifdef sun
#include <sys/vfstab.h>
static char *parse_vfstab_entries( FILE *f, dev_t dev, ino_t ino)
{
    struct vfstab entry;
    struct stat st;
    char *device;

    while (! getvfsent( f, &entry ))
    {
        /* don't even bother stat'ing network mounts, there's no meaningful device anyway */
        if (!strcmp( entry.vfs_fstype, "nfs" ) ||
            !strcmp( entry.vfs_fstype, "smbfs" ) ||
            !strcmp( entry.vfs_fstype, "ncpfs" )) continue;

        if (stat( entry.vfs_mountp, &st ) == -1) continue;
        if (st.st_dev != dev || st.st_ino != ino) continue;
        if (!strcmp( entry.vfs_fstype, "fd" ))
        {
            if ((device = strstr( entry.vfs_mntopts, "dev=" )))
            {
                char *p = strchr( device + 4, ',' );
                if (p) *p = 0;
                return device + 4;
            }
        }
        else
            return entry.vfs_special;
    }
    return NULL;
}
#endif

#ifdef linux
static char *parse_mount_entries( FILE *f, dev_t dev, ino_t ino )
{
    struct mntent *entry;
    struct stat st;
    char *device;

    while ((entry = getmntent( f )))
    {
        /* don't even bother stat'ing network mounts, there's no meaningful device anyway */
        if (!strcmp( entry->mnt_type, "nfs" ) ||
            !strcmp( entry->mnt_type, "smbfs" ) ||
            !strcmp( entry->mnt_type, "ncpfs" )) continue;

        if (stat( entry->mnt_dir, &st ) == -1) continue;
        if (st.st_dev != dev || st.st_ino != ino) continue;
        if (!strcmp( entry->mnt_type, "supermount" ))
        {
            if ((device = strstr( entry->mnt_opts, "dev=" )))
            {
                char *p = strchr( device + 4, ',' );
                if (p) *p = 0;
                return device + 4;
            }
        }
        else if (!stat( entry->mnt_fsname, &st ) && S_ISREG(st.st_mode))
        {
            /* if device is a regular file check for a loop mount */
            if ((device = strstr( entry->mnt_opts, "loop=" )))
            {
                char *p = strchr( device + 5, ',' );
                if (p) *p = 0;
                return device + 5;
            }
        }
        else
            return entry->mnt_fsname;
    }
    return NULL;
}
#endif

#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
#include <fstab.h>
static char *parse_mount_entries( FILE *f, dev_t dev, ino_t ino )
{
    struct fstab *entry;
    struct stat st;

    while ((entry = getfsent()))
    {
        /* don't even bother stat'ing network mounts, there's no meaningful device anyway */
        if (!strcmp( entry->fs_vfstype, "nfs" ) ||
            !strcmp( entry->fs_vfstype, "smbfs" ) ||
            !strcmp( entry->fs_vfstype, "ncpfs" )) continue;

        if (stat( entry->fs_file, &st ) == -1) continue;
        if (st.st_dev != dev || st.st_ino != ino) continue;
        return entry->fs_spec;
    }
    return NULL;
}
#endif

#ifdef sun
#include <sys/mnttab.h>
static char *parse_mount_entries( FILE *f, dev_t dev, ino_t ino )
{
    struct mnttab entry;
    struct stat st;
    char *device;


    while (( ! getmntent( f, &entry) ))
    {
        /* don't even bother stat'ing network mounts, there's no meaningful device anyway */
        if (!strcmp( entry.mnt_fstype, "nfs" ) ||
            !strcmp( entry.mnt_fstype, "smbfs" ) ||
            !strcmp( entry.mnt_fstype, "ncpfs" )) continue;

        if (stat( entry.mnt_mountp, &st ) == -1) continue;
        if (st.st_dev != dev || st.st_ino != ino) continue;
        if (!strcmp( entry.mnt_fstype, "fd" ))
        {
            if ((device = strstr( entry.mnt_mntopts, "dev=" )))
            {
                char *p = strchr( device + 4, ',' );
                if (p) *p = 0;
                return device + 4;
            }
        }
        else
            return entry.mnt_special;
    }
    return NULL;
}
#endif

/***********************************************************************
 *           get_default_drive_device
 *
 * Return the default device to use for a given drive mount point.
 */
static char *get_default_drive_device( const char *root )
{
    char *ret = NULL;

#ifdef linux
    FILE *f;
    char *device = NULL;
    int fd, res = -1;
    struct stat st;

    /* try to open it first to force it to get mounted */
    if ((fd = open( root, O_RDONLY | O_DIRECTORY )) != -1)
    {
        res = fstat( fd, &st );
        close( fd );
    }
    /* now try normal stat just in case */
    if (res == -1) res = stat( root, &st );
    if (res == -1) return NULL;

    RtlEnterCriticalSection( &dir_section );

#ifdef __ANDROID__
    if ((f = fopen( "/proc/mounts", "r" )))
    {
        device = parse_mount_entries( f, st.st_dev, st.st_ino );
        fclose( f );
    }
#else
    if ((f = fopen( "/etc/mtab", "r" )))
    {
        device = parse_mount_entries( f, st.st_dev, st.st_ino );
        fclose( f );
    }
    /* look through fstab too in case it's not mounted (for instance if it's an audio CD) */
    if (!device && (f = fopen( "/etc/fstab", "r" )))
    {
        device = parse_mount_entries( f, st.st_dev, st.st_ino );
        fclose( f );
    }
#endif
    if (device)
    {
        ret = RtlAllocateHeap( GetProcessHeap(), 0, strlen(device) + 1 );
        if (ret) strcpy( ret, device );
    }
    RtlLeaveCriticalSection( &dir_section );

#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__ ) || defined(__DragonFly__)
    char *device = NULL;
    int fd, res = -1;
    struct stat st;

    /* try to open it first to force it to get mounted */
    if ((fd = open( root, O_RDONLY )) != -1)
    {
        res = fstat( fd, &st );
        close( fd );
    }
    /* now try normal stat just in case */
    if (res == -1) res = stat( root, &st );
    if (res == -1) return NULL;

    RtlEnterCriticalSection( &dir_section );

    /* The FreeBSD parse_mount_entries doesn't require a file argument, so just
     * pass NULL.  Leave the argument in for symmetry.
     */
    device = parse_mount_entries( NULL, st.st_dev, st.st_ino );
    if (device)
    {
        ret = RtlAllocateHeap( GetProcessHeap(), 0, strlen(device) + 1 );
        if (ret) strcpy( ret, device );
    }
    RtlLeaveCriticalSection( &dir_section );

#elif defined( sun )
    FILE *f;
    char *device = NULL;
    int fd, res = -1;
    struct stat st;

    /* try to open it first to force it to get mounted */
    if ((fd = open( root, O_RDONLY )) != -1)
    {
        res = fstat( fd, &st );
        close( fd );
    }
    /* now try normal stat just in case */
    if (res == -1) res = stat( root, &st );
    if (res == -1) return NULL;

    RtlEnterCriticalSection( &dir_section );

    if ((f = fopen( "/etc/mnttab", "r" )))
    {
        device = parse_mount_entries( f, st.st_dev, st.st_ino);
        fclose( f );
    }
    /* look through fstab too in case it's not mounted (for instance if it's an audio CD) */
    if (!device && (f = fopen( "/etc/vfstab", "r" )))
    {
        device = parse_vfstab_entries( f, st.st_dev, st.st_ino );
        fclose( f );
    }
    if (device)
    {
        ret = RtlAllocateHeap( GetProcessHeap(), 0, strlen(device) + 1 );
        if (ret) strcpy( ret, device );
    }
    RtlLeaveCriticalSection( &dir_section );

#elif defined(__APPLE__)
    struct statfs *mntStat;
    struct stat st;
    int i;
    int mntSize;
    dev_t dev;
    ino_t ino;
    static const char path_bsd_device[] = "/dev/disk";
    int res;

    res = stat( root, &st );
    if (res == -1) return NULL;

    dev = st.st_dev;
    ino = st.st_ino;

    RtlEnterCriticalSection( &dir_section );

    mntSize = getmntinfo(&mntStat, MNT_NOWAIT);

    for (i = 0; i < mntSize && !ret; i++)
    {
        if (stat(mntStat[i].f_mntonname, &st ) == -1) continue;
        if (st.st_dev != dev || st.st_ino != ino) continue;

        /* FIXME add support for mounted network drive */
        if ( strncmp(mntStat[i].f_mntfromname, path_bsd_device, strlen(path_bsd_device)) == 0)
        {
            /* set return value to the corresponding raw BSD node */
            ret = RtlAllocateHeap( GetProcessHeap(), 0, strlen(mntStat[i].f_mntfromname) + 2 /* 2 : r and \0 */ );
            if (ret)
            {
                strcpy(ret, "/dev/r");
                strcat(ret, mntStat[i].f_mntfromname+sizeof("/dev/")-1);
            }
        }
    }
    RtlLeaveCriticalSection( &dir_section );
#else
    static int warned;
    if (!warned++) FIXME( "auto detection of DOS devices not supported on this platform\n" );
#endif
    return ret;
}


/***********************************************************************
 *           get_device_mount_point
 *
 * Return the current mount point for a device.
 */
static char *get_device_mount_point( dev_t dev )
{
    char *ret = NULL;

#ifdef linux
    FILE *f;

    RtlEnterCriticalSection( &dir_section );

#ifdef __ANDROID__
    if ((f = fopen( "/proc/mounts", "r" )))
#else
    if ((f = fopen( "/etc/mtab", "r" )))
#endif
    {
        struct mntent *entry;
        struct stat st;
        char *p, *device;

        while ((entry = getmntent( f )))
        {
            /* don't even bother stat'ing network mounts, there's no meaningful device anyway */
            if (!strcmp( entry->mnt_type, "nfs" ) ||
                !strcmp( entry->mnt_type, "smbfs" ) ||
                !strcmp( entry->mnt_type, "ncpfs" )) continue;

            if (!strcmp( entry->mnt_type, "supermount" ))
            {
                if ((device = strstr( entry->mnt_opts, "dev=" )))
                {
                    device += 4;
                    if ((p = strchr( device, ',' ))) *p = 0;
                }
            }
            else if (!stat( entry->mnt_fsname, &st ) && S_ISREG(st.st_mode))
            {
                /* if device is a regular file check for a loop mount */
                if ((device = strstr( entry->mnt_opts, "loop=" )))
                {
                    device += 5;
                    if ((p = strchr( device, ',' ))) *p = 0;
                }
            }
            else device = entry->mnt_fsname;

            if (device && !stat( device, &st ) && S_ISBLK(st.st_mode) && st.st_rdev == dev)
            {
                ret = RtlAllocateHeap( GetProcessHeap(), 0, strlen(entry->mnt_dir) + 1 );
                if (ret) strcpy( ret, entry->mnt_dir );
                break;
            }
        }
        fclose( f );
    }
    RtlLeaveCriticalSection( &dir_section );
#elif defined(__APPLE__)
    struct statfs *entry;
    struct stat st;
    int i, size;

    RtlEnterCriticalSection( &dir_section );

    size = getmntinfo( &entry, MNT_NOWAIT );
    for (i = 0; i < size; i++)
    {
        if (stat( entry[i].f_mntfromname, &st ) == -1) continue;
        if (S_ISBLK(st.st_mode) && st.st_rdev == dev)
        {
            ret = RtlAllocateHeap( GetProcessHeap(), 0, strlen(entry[i].f_mntonname) + 1 );
            if (ret) strcpy( ret, entry[i].f_mntonname );
            break;
        }
    }
    RtlLeaveCriticalSection( &dir_section );
#else
    static int warned;
    if (!warned++) FIXME( "unmounting devices not supported on this platform\n" );
#endif
    return ret;
}


#if defined(HAVE_GETATTRLIST) && defined(ATTR_VOL_CAPABILITIES) && \
    defined(VOL_CAPABILITIES_FORMAT) && defined(VOL_CAP_FMT_CASE_SENSITIVE)

struct get_fsid
{
    ULONG size;
    dev_t dev;
    fsid_t fsid;
};

struct fs_cache
{
    dev_t dev;
    fsid_t fsid;
    BOOLEAN case_sensitive;
} fs_cache[64];

struct vol_caps
{
    ULONG size;
    vol_capabilities_attr_t caps;
};

/***********************************************************************
 *           look_up_fs_cache
 *
 * Checks if the specified file system is in the cache.
 */
static struct fs_cache *look_up_fs_cache( dev_t dev )
{
    int i;
    for (i = 0; i < sizeof(fs_cache)/sizeof(fs_cache[0]); i++)
        if (fs_cache[i].dev == dev)
            return fs_cache+i;
    return NULL;
}

/***********************************************************************
 *           add_fs_cache
 *
 * Adds the specified file system to the cache.
 */
static void add_fs_cache( dev_t dev, fsid_t fsid, BOOLEAN case_sensitive )
{
    int i;
    struct fs_cache *entry = look_up_fs_cache( dev );
    static int once = 0;
    if (entry)
    {
        /* Update the cache */
        entry->fsid = fsid;
        entry->case_sensitive = case_sensitive;
        return;
    }

    /* Add a new entry */
    for (i = 0; i < sizeof(fs_cache)/sizeof(fs_cache[0]); i++)
        if (fs_cache[i].dev == 0)
        {
            /* This entry is empty, use it */
            fs_cache[i].dev = dev;
            fs_cache[i].fsid = fsid;
            fs_cache[i].case_sensitive = case_sensitive;
            return;
        }

    /* Cache is out of space, warn */
    if (!once++)
        WARN( "FS cache is out of space, expect performance problems\n" );
}

/***********************************************************************
 *           get_dir_case_sensitivity_attr
 *
 * Checks if the volume containing the specified directory is case
 * sensitive or not. Uses getattrlist(2).
 */
static int get_dir_case_sensitivity_attr( const char *dir )
{
    char *mntpoint = NULL;
    struct attrlist attr;
    struct vol_caps caps;
    struct get_fsid get_fsid;
    struct fs_cache *entry;

    /* First get the FS ID of the volume */
    attr.bitmapcount = ATTR_BIT_MAP_COUNT;
    attr.reserved = 0;
    attr.commonattr = ATTR_CMN_DEVID|ATTR_CMN_FSID;
    attr.volattr = attr.dirattr = attr.fileattr = attr.forkattr = 0;
    get_fsid.size = 0;
    if (getattrlist( dir, &attr, &get_fsid, sizeof(get_fsid), 0 ) != 0 ||
        get_fsid.size != sizeof(get_fsid))
        return -1;
    /* Try to look it up in the cache */
    entry = look_up_fs_cache( get_fsid.dev );
    if (entry && !memcmp( &entry->fsid, &get_fsid.fsid, sizeof(fsid_t) ))
        /* Cache lookup succeeded */
        return entry->case_sensitive;
    /* Cache is stale at this point, we have to update it */

    mntpoint = get_device_mount_point( get_fsid.dev );
    /* Now look up the case-sensitivity */
    attr.commonattr = 0;
    attr.volattr = ATTR_VOL_INFO|ATTR_VOL_CAPABILITIES;
    if (getattrlist( mntpoint, &attr, &caps, sizeof(caps), 0 ) < 0)
    {
        RtlFreeHeap( GetProcessHeap(), 0, mntpoint );
        add_fs_cache( get_fsid.dev, get_fsid.fsid, TRUE );
        return TRUE;
    }
    RtlFreeHeap( GetProcessHeap(), 0, mntpoint );
    if (caps.size == sizeof(caps) &&
        (caps.caps.valid[VOL_CAPABILITIES_FORMAT] &
         (VOL_CAP_FMT_CASE_SENSITIVE | VOL_CAP_FMT_CASE_PRESERVING)) ==
        (VOL_CAP_FMT_CASE_SENSITIVE | VOL_CAP_FMT_CASE_PRESERVING))
    {
        BOOLEAN ret;

        if ((caps.caps.capabilities[VOL_CAPABILITIES_FORMAT] &
            VOL_CAP_FMT_CASE_SENSITIVE) != VOL_CAP_FMT_CASE_SENSITIVE)
            ret = FALSE;
        else
            ret = TRUE;
        /* Update the cache */
        add_fs_cache( get_fsid.dev, get_fsid.fsid, ret );
        return ret;
    }
    return FALSE;
}
#endif

/***********************************************************************
 *           get_dir_case_sensitivity_stat
 *
 * Checks if the volume containing the specified directory is case
 * sensitive or not. Uses statfs(2) or statvfs(2).
 */
static BOOLEAN get_dir_case_sensitivity_stat( const char *dir )
{
#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
    struct statfs stfs;

    if (statfs( dir, &stfs ) == -1) return FALSE;
    /* Assume these file systems are always case insensitive on Mac OS.
     * For FreeBSD, only assume CIOPFS is case insensitive (AFAIK, Mac OS
     * is the only UNIX that supports case-insensitive lookup).
     */
    if (!strcmp( stfs.f_fstypename, "fusefs" ) &&
        !strncmp( stfs.f_mntfromname, "ciopfs", 5 ))
        return FALSE;
#ifdef __APPLE__
    if (!strcmp( stfs.f_fstypename, "msdos" ) ||
        !strcmp( stfs.f_fstypename, "cd9660" ) ||
        !strcmp( stfs.f_fstypename, "udf" ) ||
        !strcmp( stfs.f_fstypename, "ntfs" ) ||
        !strcmp( stfs.f_fstypename, "smbfs" ))
        return FALSE;
#ifdef _DARWIN_FEATURE_64_BIT_INODE
     if (!strcmp( stfs.f_fstypename, "hfs" ) && (stfs.f_fssubtype == 0 ||
                                                 stfs.f_fssubtype == 1 ||
                                                 stfs.f_fssubtype == 128))
        return FALSE;
#else
     /* The field says "reserved", but a quick look at the kernel source
      * tells us that this "reserved" field is really the same as the
      * "fssubtype" field from the inode64 structure (see munge_statfs()
      * in <xnu-source>/bsd/vfs/vfs_syscalls.c).
      */
     if (!strcmp( stfs.f_fstypename, "hfs" ) && (stfs.f_reserved1 == 0 ||
                                                 stfs.f_reserved1 == 1 ||
                                                 stfs.f_reserved1 == 128))
        return FALSE;
#endif
#endif
    return TRUE;

#elif defined(__NetBSD__)
    struct statvfs stfs;

    if (statvfs( dir, &stfs ) == -1) return FALSE;
    /* Only assume CIOPFS is case insensitive. */
    if (strcmp( stfs.f_fstypename, "fusefs" ) ||
        strncmp( stfs.f_mntfromname, "ciopfs", 5 ))
        return TRUE;
    return FALSE;

#elif defined(__linux__)
    struct statfs stfs;
    struct stat st;
    char *cifile;

    /* Only assume CIOPFS is case insensitive. */
    if (statfs( dir, &stfs ) == -1) return FALSE;
    if (stfs.f_type != 0x65735546 /* FUSE_SUPER_MAGIC */)
        return TRUE;
    /* Normally, we'd have to parse the mtab to find out exactly what
     * kind of FUSE FS this is. But, someone on wine-devel suggested
     * a shortcut. We'll stat a special file in the directory. If it's
     * there, we'll assume it's a CIOPFS, else not.
     * This will break if somebody puts a file named ".ciopfs" in a non-
     * CIOPFS directory.
     */
    cifile = RtlAllocateHeap( GetProcessHeap(), 0, strlen( dir )+sizeof("/.ciopfs") );
    if (!cifile) return TRUE;
    strcpy( cifile, dir );
    strcat( cifile, "/.ciopfs" );
    if (stat( cifile, &st ) == 0)
    {
        RtlFreeHeap( GetProcessHeap(), 0, cifile );
        return FALSE;
    }
    RtlFreeHeap( GetProcessHeap(), 0, cifile );
    return TRUE;
#else
    return TRUE;
#endif
}


/***********************************************************************
 *           get_dir_case_sensitivity
 *
 * Checks if the volume containing the specified directory is case
 * sensitive or not. Uses statfs(2) or statvfs(2).
 */
static BOOLEAN get_dir_case_sensitivity( const char *dir )
{
#if defined(HAVE_GETATTRLIST) && defined(ATTR_VOL_CAPABILITIES) && \
    defined(VOL_CAPABILITIES_FORMAT) && defined(VOL_CAP_FMT_CASE_SENSITIVE)
    int case_sensitive = get_dir_case_sensitivity_attr( dir );
    if (case_sensitive != -1) return case_sensitive;
#endif
    return get_dir_case_sensitivity_stat( dir );
}


/***********************************************************************
 *           init_options
 *
 * Initialize the show_dot_files options.
 */
static DWORD WINAPI init_options( RTL_RUN_ONCE *once, void *param, void **context )
{
    static const WCHAR WineW[] = {'S','o','f','t','w','a','r','e','\\','W','i','n','e',0};
    static const WCHAR ShowDotFilesW[] = {'S','h','o','w','D','o','t','F','i','l','e','s',0};
    char tmp[80];
    HANDLE root, hkey;
    DWORD dummy;
    OBJECT_ATTRIBUTES attr;
    UNICODE_STRING nameW;

    RtlOpenCurrentUser( KEY_ALL_ACCESS, &root );
    attr.Length = sizeof(attr);
    attr.RootDirectory = root;
    attr.ObjectName = &nameW;
    attr.Attributes = 0;
    attr.SecurityDescriptor = NULL;
    attr.SecurityQualityOfService = NULL;
    RtlInitUnicodeString( &nameW, WineW );

    /* @@ Wine registry key: HKCU\Software\Wine */
    if (!NtOpenKey( &hkey, KEY_ALL_ACCESS, &attr ))
    {
        RtlInitUnicodeString( &nameW, ShowDotFilesW );
        if (!NtQueryValueKey( hkey, &nameW, KeyValuePartialInformation, tmp, sizeof(tmp), &dummy ))
        {
            WCHAR *str = (WCHAR *)((KEY_VALUE_PARTIAL_INFORMATION *)tmp)->Data;
            show_dot_files = IS_OPTION_TRUE( str[0] );
        }
        NtClose( hkey );
    }
    NtClose( root );

    /* a couple of directories that we don't want to return in directory searches */
    ignore_file( wine_get_config_dir() );
    ignore_file( "/dev" );
    ignore_file( "/proc" );
#ifdef linux
    ignore_file( "/sys" );
#endif
    return TRUE;
}


/***********************************************************************
 *           DIR_is_hidden_file
 *
 * Check if the specified file should be hidden based on its name and the show dot files option.
 */
BOOL DIR_is_hidden_file( const UNICODE_STRING *name )
{
    WCHAR *p, *end;

    RtlRunOnceExecuteOnce( &init_once, init_options, NULL, NULL );

    if (show_dot_files) return FALSE;

    end = p = name->Buffer + name->Length/sizeof(WCHAR);
    while (p > name->Buffer && IS_SEPARATOR(p[-1])) p--;
    while (p > name->Buffer && !IS_SEPARATOR(p[-1])) p--;
    if (p == end || *p != '.') return FALSE;
    /* make sure it isn't '.' or '..' */
    if (p + 1 == end) return FALSE;
    if (p[1] == '.' && p + 2 == end) return FALSE;
    return TRUE;
}


/***********************************************************************
 *           hash_short_file_name
 *
 * Transform a Unix file name into a hashed DOS name. If the name is a valid
 * DOS name, it is converted to upper-case; otherwise it is replaced by a
 * hashed version that fits in 8.3 format.
 * 'buffer' must be at least 12 characters long.
 * Returns length of short name in bytes; short name is NOT null-terminated.
 */
static ULONG hash_short_file_name( const UNICODE_STRING *name, LPWSTR buffer )
{
    static const char hash_chars[32] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ012345";

    LPCWSTR p, ext, end = name->Buffer + name->Length / sizeof(WCHAR);
    LPWSTR dst;
    unsigned short hash;
    int i;

    /* Compute the hash code of the file name */
    /* If you know something about hash functions, feel free to */
    /* insert a better algorithm here... */
    if (!is_case_sensitive)
    {
        for (p = name->Buffer, hash = 0xbeef; p < end - 1; p++)
            hash = (hash<<3) ^ (hash>>5) ^ tolowerW(*p) ^ (tolowerW(p[1]) << 8);
        hash = (hash<<3) ^ (hash>>5) ^ tolowerW(*p); /* Last character */
    }
    else
    {
        for (p = name->Buffer, hash = 0xbeef; p < end - 1; p++)
            hash = (hash << 3) ^ (hash >> 5) ^ *p ^ (p[1] << 8);
        hash = (hash << 3) ^ (hash >> 5) ^ *p;  /* Last character */
    }

    /* Find last dot for start of the extension */
    for (p = name->Buffer + 1, ext = NULL; p < end - 1; p++) if (*p == '.') ext = p;

    /* Copy first 4 chars, replacing invalid chars with '_' */
    for (i = 4, p = name->Buffer, dst = buffer; i > 0; i--, p++)
    {
        if (p == end || p == ext) break;
        *dst++ = is_invalid_dos_char(*p) ? '_' : toupperW(*p);
    }
    /* Pad to 5 chars with '~' */
    while (i-- >= 0) *dst++ = '~';

    /* Insert hash code converted to 3 ASCII chars */
    *dst++ = hash_chars[(hash >> 10) & 0x1f];
    *dst++ = hash_chars[(hash >> 5) & 0x1f];
    *dst++ = hash_chars[hash & 0x1f];

    /* Copy the first 3 chars of the extension (if any) */
    if (ext)
    {
        *dst++ = '.';
        for (i = 3, ext++; (i > 0) && ext < end; i--, ext++)
            *dst++ = is_invalid_dos_char(*ext) ? '_' : toupperW(*ext);
    }
    return dst - buffer;
}


/***********************************************************************
 *           match_filename
 *
 * Check a long file name against a mask.
 *
 * Tests (done in W95 DOS shell - case insensitive):
 * *.txt			test1.test.txt				*
 * *st1*			test1.txt				*
 * *.t??????.t*			test1.ta.tornado.txt			*
 * *tornado*			test1.ta.tornado.txt			*
 * t*t				test1.ta.tornado.txt			*
 * ?est*			test1.txt				*
 * ?est???			test1.txt				-
 * *test1.txt*			test1.txt				*
 * h?l?o*t.dat			hellothisisatest.dat			*
 */
static BOOLEAN match_filename( const UNICODE_STRING *name_str, const UNICODE_STRING *mask_str )
{
    BOOL mismatch;
    const WCHAR *name = name_str->Buffer;
    const WCHAR *mask = mask_str->Buffer;
    const WCHAR *name_end = name + name_str->Length / sizeof(WCHAR);
    const WCHAR *mask_end = mask + mask_str->Length / sizeof(WCHAR);
    const WCHAR *lastjoker = NULL;
    const WCHAR *next_to_retry = NULL;

    TRACE("(%s, %s)\n", debugstr_us(name_str), debugstr_us(mask_str));

    while (name < name_end && mask < mask_end)
    {
        switch(*mask)
        {
        case '*':
            mask++;
            while (mask < mask_end && *mask == '*') mask++;  /* Skip consecutive '*' */
            if (mask == mask_end) return TRUE; /* end of mask is all '*', so match */
            lastjoker = mask;

            /* skip to the next match after the joker(s) */
            if (is_case_sensitive)
                while (name < name_end && (*name != *mask)) name++;
            else
                while (name < name_end && (toupperW(*name) != toupperW(*mask))) name++;
            next_to_retry = name;
            break;
        case '?':
            mask++;
            name++;
            break;
        default:
            if (is_case_sensitive) mismatch = (*mask != *name);
            else mismatch = (toupperW(*mask) != toupperW(*name));

            if (!mismatch)
            {
                mask++;
                name++;
                if (mask == mask_end)
                {
                    if (name == name_end) return TRUE;
                    if (lastjoker) mask = lastjoker;
                }
            }
            else /* mismatch ! */
            {
                if (lastjoker) /* we had an '*', so we can try unlimitedly */
                {
                    mask = lastjoker;

                    /* this scan sequence was a mismatch, so restart
                     * 1 char after the first char we checked last time */
                    next_to_retry++;
                    name = next_to_retry;
                }
                else return FALSE; /* bad luck */
            }
            break;
        }
    }
    while (mask < mask_end && ((*mask == '.') || (*mask == '*')))
        mask++;  /* Ignore trailing '.' or '*' in mask */
    return (name == name_end && mask == mask_end);
}


/***********************************************************************
 *           append_entry
 *
 * helper for NtQueryDirectoryFile
 */
static union file_directory_info *append_entry( void *info_ptr, IO_STATUS_BLOCK *io, ULONG max_length,
                                                const char *long_name, const char *short_name,
                                                const UNICODE_STRING *mask, FILE_INFORMATION_CLASS class )
{
    union file_directory_info *info;
    int i, long_len, short_len, total_len;
    struct stat st;
    WCHAR long_nameW[MAX_DIR_ENTRY_LEN] = { (WCHAR)0 };
    WCHAR short_nameW[12];
    WCHAR *filename;
    UNICODE_STRING str;
    ULONG attributes = 0;

    io->u.Status = STATUS_SUCCESS;
    long_len = ntdll_umbstowcs( 0, long_name, strlen(long_name), long_nameW, MAX_DIR_ENTRY_LEN );
    if (long_len == -1) return NULL;

    str.Buffer = long_nameW;
    str.Length = long_len * sizeof(WCHAR);
    str.MaximumLength = sizeof(long_nameW);

    if (short_name)
    {
        short_len = ntdll_umbstowcs( 0, short_name, strlen(short_name),
                                     short_nameW, sizeof(short_nameW) / sizeof(WCHAR) );
        if (short_len == -1) short_len = sizeof(short_nameW) / sizeof(WCHAR);
    }
    else  /* generate a short name if necessary */
    {
        BOOLEAN spaces;

        short_len = 0;
        if (!RtlIsNameLegalDOS8Dot3( &str, NULL, &spaces ) || spaces)
            short_len = hash_short_file_name( &str, short_nameW );
    }

    TRACE( "long %s short %s mask %s\n",
           debugstr_us(&str), debugstr_wn(short_nameW, short_len), debugstr_us(mask) );

    if (mask && !match_filename( &str, mask ))
    {
        if (!short_len) return NULL;  /* no short name to match */
        str.Buffer = short_nameW;
        str.Length = short_len * sizeof(WCHAR);
        str.MaximumLength = sizeof(short_nameW);
        if (!match_filename( &str, mask )) return NULL;
    }

    if (lstat( long_name, &st ) == -1) return NULL;
    if (S_ISLNK( st.st_mode ))
    {
        if (stat( long_name, &st ) == -1) return NULL;
        if (S_ISDIR( st.st_mode )) attributes |= FILE_ATTRIBUTE_REPARSE_POINT;
    }
    if (is_ignored_file( &st ))
    {
        TRACE( "ignoring file %s\n", long_name );
        return NULL;
    }
    if (!show_dot_files && long_name[0] == '.' && long_name[1] && (long_name[1] != '.' || long_name[2]))
        attributes |= FILE_ATTRIBUTE_HIDDEN;

    total_len = dir_info_size( class, long_len );
    if (io->Information + total_len > max_length)
    {
        total_len = max_length - io->Information;
        io->u.Status = STATUS_BUFFER_OVERFLOW;
    }
    info = (union file_directory_info *)((char *)info_ptr + io->Information);
    if (st.st_dev != curdir.dev) st.st_ino = 0;  /* ignore inode if on a different device */
    /* all the structures start with a FileDirectoryInformation layout */
    fill_stat_info( &st, info, class );
    info->dir.NextEntryOffset = total_len;
    info->dir.FileIndex = 0;  /* NTFS always has 0 here, so let's not bother with it */
    info->dir.FileAttributes |= attributes;

    switch (class)
    {
    case FileDirectoryInformation:
        info->dir.FileNameLength = long_len * sizeof(WCHAR);
        filename = info->dir.FileName;
        break;

    case FileFullDirectoryInformation:
        info->full.EaSize = 0; /* FIXME */
        info->full.FileNameLength = long_len * sizeof(WCHAR);
        filename = info->full.FileName;
        break;

    case FileIdFullDirectoryInformation:
        info->id_full.EaSize = 0; /* FIXME */
        info->id_full.FileNameLength = long_len * sizeof(WCHAR);
        filename = info->id_full.FileName;
        break;

    case FileBothDirectoryInformation:
        info->both.EaSize = 0; /* FIXME */
        info->both.ShortNameLength = short_len * sizeof(WCHAR);
        for (i = 0; i < short_len; i++) info->both.ShortName[i] = toupperW(short_nameW[i]);
        info->both.FileNameLength = long_len * sizeof(WCHAR);
        filename = info->both.FileName;
        break;

    case FileIdBothDirectoryInformation:
        info->id_both.EaSize = 0; /* FIXME */
        info->id_both.ShortNameLength = short_len * sizeof(WCHAR);
        for (i = 0; i < short_len; i++) info->id_both.ShortName[i] = toupperW(short_nameW[i]);
        info->id_both.FileNameLength = long_len * sizeof(WCHAR);
        filename = info->id_both.FileName;
        break;

    default:
        assert(0);
        return NULL;
    }
    memcpy( filename, long_nameW, long_len * sizeof(WCHAR) );
    io->Information += total_len;
    return info;
}


#ifdef VFAT_IOCTL_READDIR_BOTH

/***********************************************************************
 *           start_vfat_ioctl
 *
 * Wrapper for the VFAT ioctl to work around various kernel bugs.
 * dir_section must be held by caller.
 */
static KERNEL_DIRENT *start_vfat_ioctl( int fd )
{
    static KERNEL_DIRENT *de;
    int res;

    if (!de)
    {
        SIZE_T size = 2 * sizeof(*de) + page_size;
        void *addr = NULL;

        if (NtAllocateVirtualMemory( GetCurrentProcess(), &addr, 1, &size, MEM_RESERVE, PAGE_READWRITE ))
            return NULL;
        /* commit only the size needed for the dir entries */
        /* this leaves an extra unaccessible page, which should make the kernel */
        /* fail with -EFAULT before it stomps all over our memory */
        de = addr;
        size = 2 * sizeof(*de);
        NtAllocateVirtualMemory( GetCurrentProcess(), &addr, 1, &size, MEM_COMMIT, PAGE_READWRITE );
    }

    /* set d_reclen to 65535 to work around an AFS kernel bug */
    de[0].d_reclen = 65535;
    res = ioctl( fd, VFAT_IOCTL_READDIR_BOTH, (long)de );
    if (res == -1)
    {
        if (errno != ENOENT) return NULL;  /* VFAT ioctl probably not supported */
        de[0].d_reclen = 0;  /* eof */
    }
    else if (!res && de[0].d_reclen == 65535) return NULL;  /* AFS bug */

    return de;
}


/***********************************************************************
 *           read_directory_vfat
 *
 * Read a directory using the VFAT ioctl; helper for NtQueryDirectoryFile.
 */
static int read_directory_vfat( int fd, IO_STATUS_BLOCK *io, void *buffer, ULONG length,
                                BOOLEAN single_entry, const UNICODE_STRING *mask,
                                BOOLEAN restart_scan, FILE_INFORMATION_CLASS class )

{
    size_t len;
    KERNEL_DIRENT *de;
    union file_directory_info *info, *last_info = NULL;

    io->u.Status = STATUS_SUCCESS;

    if (restart_scan) lseek( fd, 0, SEEK_SET );

    if (length < max_dir_info_size(class))  /* we may have to return a partial entry here */
    {
        off_t old_pos = lseek( fd, 0, SEEK_CUR );

        if (!(de = start_vfat_ioctl( fd ))) return -1;  /* not supported */

        while (de[0].d_reclen)
        {
            /* make sure names are null-terminated to work around an x86-64 kernel bug */
            len = min(de[0].d_reclen, sizeof(de[0].d_name) - 1 );
            de[0].d_name[len] = 0;
            len = min(de[1].d_reclen, sizeof(de[1].d_name) - 1 );
            de[1].d_name[len] = 0;

            if (de[1].d_name[0])
                info = append_entry( buffer, io, length, de[1].d_name, de[0].d_name, mask, class );
            else
                info = append_entry( buffer, io, length, de[0].d_name, NULL, mask, class );
            if (info)
            {
                last_info = info;
                if (io->u.Status == STATUS_BUFFER_OVERFLOW)
                    lseek( fd, old_pos, SEEK_SET );  /* restore pos to previous entry */
                break;
            }
            old_pos = lseek( fd, 0, SEEK_CUR );
            if (ioctl( fd, VFAT_IOCTL_READDIR_BOTH, (long)de ) == -1) break;
        }
    }
    else  /* we'll only return full entries, no need to worry about overflow */
    {
        if (!(de = start_vfat_ioctl( fd ))) return -1;  /* not supported */

        while (de[0].d_reclen)
        {
            /* make sure names are null-terminated to work around an x86-64 kernel bug */
            len = min(de[0].d_reclen, sizeof(de[0].d_name) - 1 );
            de[0].d_name[len] = 0;
            len = min(de[1].d_reclen, sizeof(de[1].d_name) - 1 );
            de[1].d_name[len] = 0;

            if (de[1].d_name[0])
                info = append_entry( buffer, io, length, de[1].d_name, de[0].d_name, mask, class );
            else
                info = append_entry( buffer, io, length, de[0].d_name, NULL, mask, class );
            if (info)
            {
                last_info = info;
                if (single_entry) break;
                /* check if we still have enough space for the largest possible entry */
                if (io->Information + max_dir_info_size(class) > length) break;
            }
            if (ioctl( fd, VFAT_IOCTL_READDIR_BOTH, (long)de ) == -1) break;
        }
    }

    if (last_info) last_info->next = 0;
    else io->u.Status = restart_scan ? STATUS_NO_SUCH_FILE : STATUS_NO_MORE_FILES;
    return 0;
}
#endif /* VFAT_IOCTL_READDIR_BOTH */


#ifdef USE_GETDENTS
/***********************************************************************
 *           read_first_dent_name
 *
 * reads name of first or second dentry (if they have inodes).
 */
static char *read_first_dent_name( int which, int fd, off_t second_offs, KERNEL_DIRENT64 *de_first_two,
                                   char *buffer, size_t size, BOOL *buffer_changed )
{
    KERNEL_DIRENT64 *de;
    int res;

    de = de_first_two;
    if (de != NULL)
    {
        if (which == 1)
            de = (KERNEL_DIRENT64 *)((char *)de + de->d_reclen);

        return de->d_ino ? de->d_name : NULL;
    }

    *buffer_changed = TRUE;
    lseek( fd, which == 1 ? second_offs : 0, SEEK_SET );
    res = getdents64( fd, buffer, size );
    if (res <= 0)
        return NULL;

    de = (KERNEL_DIRENT64 *)buffer;
    return de->d_ino ? de->d_name : NULL;
}

/***********************************************************************
 *           read_directory_getdents
 *
 * Read a directory using the Linux getdents64 system call; helper for NtQueryDirectoryFile.
 */
static int read_directory_getdents( int fd, IO_STATUS_BLOCK *io, void *buffer, ULONG length,
                                    BOOLEAN single_entry, const UNICODE_STRING *mask,
                                    BOOLEAN restart_scan, FILE_INFORMATION_CLASS class )
{
    static off_t second_entry_pos;
    static struct file_identity last_dir_id;
    off_t old_pos = 0, next_pos;
    size_t size = length;
    char *data, local_buffer[8192];
    KERNEL_DIRENT64 *de, *de_first_two = NULL;
    union file_directory_info *info, *last_info = NULL;
    const char *filename;
    BOOL data_buffer_changed;
    int res, swap_to;

    if (size <= sizeof(local_buffer) || !(data = RtlAllocateHeap( GetProcessHeap(), 0, size )))
    {
        size = sizeof(local_buffer);
        data = local_buffer;
    }

    if (restart_scan) lseek( fd, 0, SEEK_SET );
    else
    {
        old_pos = lseek( fd, 0, SEEK_CUR );
        if (old_pos == -1)
        {
            io->u.Status = (errno == ENOENT) ? STATUS_NO_MORE_FILES : FILE_GetNtStatus();
            res = 0;
            goto done;
        }
    }

    io->u.Status = STATUS_SUCCESS;
    de = (KERNEL_DIRENT64 *)data;

    /* if old_pos is not 0 we don't know how many entries have been returned already,
     * so maintain second_entry_pos to know when to return '..' */
    if (old_pos != 0 && (last_dir_id.dev != curdir.dev || last_dir_id.ino != curdir.ino))
    {
        lseek( fd, 0, SEEK_SET );
        res = getdents64( fd, data, size );
        if (res > 0)
        {
            second_entry_pos = de->d_off;
            last_dir_id = curdir;
        }
        lseek( fd, old_pos, SEEK_SET );
    }

    res = getdents64( fd, data, size );
    if (res == -1)
    {
        if (errno != ENOSYS)
        {
            io->u.Status = FILE_GetNtStatus();
            res = 0;
        }
        goto done;
    }

    if (old_pos == 0 && res > 0)
    {
        second_entry_pos = de->d_off;
        last_dir_id = curdir;
        if (res > de->d_reclen)
            de_first_two = de;
    }

    while (res > 0)
    {
        res -= de->d_reclen;
        next_pos = de->d_off;
        filename = NULL;

        /* we must return first 2 entries as "." and "..", but getdents64()
         * can return them anywhere, so swap first entries with "." and ".." */
        if (old_pos == 0)
            filename = ".";
        else if (old_pos == second_entry_pos)
            filename = "..";
        else if (!strcmp( de->d_name, "." ) || !strcmp( de->d_name, ".." ))
        {
            swap_to = !strcmp( de->d_name, "." ) ? 0 : 1;
            data_buffer_changed = FALSE;

            filename = read_first_dent_name( swap_to, fd, second_entry_pos, de_first_two,
                                             data, size, &data_buffer_changed );
            if (filename != NULL && (!strcmp( filename, "." ) || !strcmp( filename, ".." )))
                filename = read_first_dent_name( swap_to ^ 1, fd, second_entry_pos, NULL,
                                                 data, size, &data_buffer_changed );
            if (data_buffer_changed)
            {
                lseek( fd, next_pos, SEEK_SET );
                res = 0;
            }
        }
        else if (de->d_ino)
            filename = de->d_name;

        if (filename && (info = append_entry( buffer, io, length, filename, NULL, mask, class )))
        {
            last_info = info;
            if (io->u.Status == STATUS_BUFFER_OVERFLOW)
            {
                lseek( fd, old_pos, SEEK_SET );  /* restore pos to previous entry */
                break;
            }
            /* check if we still have enough space for the largest possible entry */
            if (single_entry || io->Information + max_dir_info_size(class) > length)
            {
                if (res > 0) lseek( fd, next_pos, SEEK_SET );  /* set pos to next entry */
                break;
            }
        }
        old_pos = next_pos;
        /* move on to the next entry */
        if (res > 0) de = (KERNEL_DIRENT64 *)((char *)de + de->d_reclen);
        else
        {
            res = getdents64( fd, data, size );
            de = (KERNEL_DIRENT64 *)data;
            de_first_two = NULL;
        }
    }

    if (last_info) last_info->next = 0;
    else io->u.Status = restart_scan ? STATUS_NO_SUCH_FILE : STATUS_NO_MORE_FILES;
    res = 0;
done:
    if (data != local_buffer) RtlFreeHeap( GetProcessHeap(), 0, data );
    return res;
}

#elif defined HAVE_GETDIRENTRIES

#ifdef _DARWIN_FEATURE_64_BIT_INODE

/* Darwin doesn't provide a version of getdirentries with support for 64-bit
 * inodes.  When 64-bit inodes are enabled, the getdirentries symbol is mapped
 * to _getdirentries_is_not_available_when_64_bit_inodes_are_in_effect so that
 * we get link errors if we try to use it.  We still need getdirentries, but we
 * don't need it to support 64-bit inodes.  So, we use the legacy getdirentries
 * with 32-bit inodes.  We have to be careful to use a corresponding dirent
 * structure, too.
 */
int darwin_legacy_getdirentries(int, char *, int, long *) __asm("_getdirentries");
#define getdirentries darwin_legacy_getdirentries

struct darwin_legacy_dirent {
    __uint32_t d_ino;
    __uint16_t d_reclen;
    __uint8_t  d_type;
    __uint8_t  d_namlen;
    char d_name[__DARWIN_MAXNAMLEN + 1];
};
#define dirent darwin_legacy_dirent

#endif

/***********************************************************************
 *           wine_getdirentries
 *
 * Wrapper for the BSD getdirentries system call to fix a bug in the
 * Mac OS X version.  For some file systems (at least Apple Filing
 * Protocol a.k.a. AFP), getdirentries resets the file position to 0
 * when it's about to return 0 (no more entries).  So, a subsequent
 * getdirentries call starts over at the beginning again, causing an
 * infinite loop.
 */
static inline int wine_getdirentries(int fd, char *buf, int nbytes, long *basep)
{
    int res = getdirentries(fd, buf, nbytes, basep);
#ifdef __APPLE__
    if (res == 0)
        lseek(fd, *basep, SEEK_SET);
#endif
    return res;
}

static inline int dir_reclen(struct dirent *de)
{
#ifdef HAVE_STRUCT_DIRENT_D_RECLEN
    return de->d_reclen;
#else
    return _DIRENT_RECLEN(de->d_namlen);
#endif
}

/***********************************************************************
 *           read_directory_getdirentries
 *
 * Read a directory using the BSD getdirentries system call; helper for NtQueryDirectoryFile.
 */
static int read_directory_getdirentries( int fd, IO_STATUS_BLOCK *io, void *buffer, ULONG length,
                                         BOOLEAN single_entry, const UNICODE_STRING *mask,
                                         BOOLEAN restart_scan, FILE_INFORMATION_CLASS class )
{
    long restart_pos;
    ULONG_PTR restart_info_pos = 0;
    size_t size, initial_size = length;
    int res, fake_dot_dot = 1;
    char *data, local_buffer[8192];
    struct dirent *de;
    union file_directory_info *info, *last_info = NULL, *restart_last_info = NULL;

    size = initial_size;
    data = local_buffer;
    if (size > sizeof(local_buffer) && !(data = RtlAllocateHeap( GetProcessHeap(), 0, size )))
    {
        io->u.Status = STATUS_NO_MEMORY;
        return io->u.Status;
    }

    if (restart_scan) lseek( fd, 0, SEEK_SET );

    io->u.Status = STATUS_SUCCESS;

    /* FIXME: should make sure size is larger than filesystem block size */
    res = wine_getdirentries( fd, data, size, &restart_pos );
    if (res == -1)
    {
        io->u.Status = FILE_GetNtStatus();
        res = 0;
        goto done;
    }

    de = (struct dirent *)data;

    if (restart_scan)
    {
        /* check if we got . and .. from getdirentries */
        if (res > 0)
        {
            if (!strcmp( de->d_name, "." ) && res > dir_reclen(de))
            {
                struct dirent *next_de = (struct dirent *)(data + dir_reclen(de));
                if (!strcmp( next_de->d_name, ".." )) fake_dot_dot = 0;
            }
        }
        /* make sure we have enough room for both entries */
        if (fake_dot_dot)
        {
            const ULONG min_info_size = dir_info_size( class, 1 ) + dir_info_size( class, 2 );
            if (length < min_info_size || single_entry)
            {
                FIXME( "not enough room %u/%u for fake . and .. entries\n", length, single_entry );
                fake_dot_dot = 0;
            }
        }

        if (fake_dot_dot)
        {
            if ((info = append_entry( buffer, io, length, ".", NULL, mask, class )))
                last_info = info;
            if ((info = append_entry( buffer, io, length, "..", NULL, mask, class )))
                last_info = info;

            restart_last_info = last_info;
            restart_info_pos = io->Information;

            /* check if we still have enough space for the largest possible entry */
            if (last_info && io->Information + max_dir_info_size(class) > length)
            {
                lseek( fd, 0, SEEK_SET );  /* reset pos to first entry */
                res = 0;
            }
        }
    }

    while (res > 0)
    {
        res -= dir_reclen(de);
        if (de->d_fileno &&
            !(fake_dot_dot && (!strcmp( de->d_name, "." ) || !strcmp( de->d_name, ".." ))) &&
            ((info = append_entry( buffer, io, length, de->d_name, NULL, mask, class ))))
        {
            last_info = info;
            if (io->u.Status == STATUS_BUFFER_OVERFLOW)
            {
                lseek( fd, (unsigned long)restart_pos, SEEK_SET );
                if (restart_info_pos)  /* if we have a complete read already, return it */
                {
                    io->u.Status = STATUS_SUCCESS;
                    io->Information = restart_info_pos;
                    last_info = restart_last_info;
                    break;
                }
                /* otherwise restart from the start with a smaller size */
                size = (char *)de - data;
                if (!size) break;
                io->Information = 0;
                last_info = NULL;
                goto restart;
            }
            if (!has_wildcard( mask )) break;
            /* if we have to return but the buffer contains more data, restart with a smaller size */
            if (res > 0 && (single_entry || io->Information + max_dir_info_size(class) > length))
            {
                lseek( fd, (unsigned long)restart_pos, SEEK_SET );
                size = (char *)de + dir_reclen(de) - data;
                io->Information = restart_info_pos;
                last_info = restart_last_info;
                goto restart;
            }
        }
        /* move on to the next entry */
        if (res > 0)
        {
            de = (struct dirent *)((char *)de + dir_reclen(de));
            continue;
        }
        if (size < initial_size) break;  /* already restarted once, give up now */
        restart_last_info = last_info;
        restart_info_pos = io->Information;
    restart:
        res = wine_getdirentries( fd, data, size, &restart_pos );
        de = (struct dirent *)data;
    }

    if (last_info) last_info->next = 0;
    else io->u.Status = restart_scan ? STATUS_NO_SUCH_FILE : STATUS_NO_MORE_FILES;
    res = 0;
done:
    if (data != local_buffer) RtlFreeHeap( GetProcessHeap(), 0, data );
    return res;
}

#ifdef _DARWIN_FEATURE_64_BIT_INODE
#undef getdirentries
#undef dirent
#endif

#endif  /* HAVE_GETDIRENTRIES */


/***********************************************************************
 *           read_directory_readdir
 *
 * Read a directory using the POSIX readdir interface; helper for NtQueryDirectoryFile.
 */
static void read_directory_readdir( int fd, IO_STATUS_BLOCK *io, void *buffer, ULONG length,
                                    BOOLEAN single_entry, const UNICODE_STRING *mask,
                                    BOOLEAN restart_scan, FILE_INFORMATION_CLASS class )
{
    DIR *dir;
    off_t i, old_pos = 0;
    struct dirent *de;
    union file_directory_info *info, *last_info = NULL;

    if (!(dir = opendir( "." )))
    {
        io->u.Status = FILE_GetNtStatus();
        return;
    }

    if (!restart_scan)
    {
        old_pos = lseek( fd, 0, SEEK_CUR );
        /* skip the right number of entries */
        for (i = 0; i < old_pos - 2; i++)
        {
            if (!readdir( dir ))
            {
                closedir( dir );
                io->u.Status = STATUS_NO_MORE_FILES;
                return;
            }
        }
    }
    io->u.Status = STATUS_SUCCESS;

    for (;;)
    {
        if (old_pos == 0)
            info = append_entry( buffer, io, length, ".", NULL, mask, class );
        else if (old_pos == 1)
            info = append_entry( buffer, io, length, "..", NULL, mask, class );
        else if ((de = readdir( dir )))
        {
            if (strcmp( de->d_name, "." ) && strcmp( de->d_name, ".." ))
                info = append_entry( buffer, io, length, de->d_name, NULL, mask, class );
            else
                info = NULL;
        }
        else
            break;
        old_pos++;
        if (info)
        {
            last_info = info;
            if (io->u.Status == STATUS_BUFFER_OVERFLOW)
            {
                old_pos--;  /* restore pos to previous entry */
                break;
            }
            if (single_entry) break;
            /* check if we still have enough space for the largest possible entry */
            if (io->Information + max_dir_info_size(class) > length) break;
        }
    }

    lseek( fd, old_pos, SEEK_SET );  /* store dir offset as filepos for fd */
    closedir( dir );

    if (last_info) last_info->next = 0;
    else io->u.Status = restart_scan ? STATUS_NO_SUCH_FILE : STATUS_NO_MORE_FILES;
}

/***********************************************************************
 *           read_directory_stat
 *
 * Read a single file from a directory by determining whether the file
 * identified by mask exists using stat.
 */
static int read_directory_stat( int fd, IO_STATUS_BLOCK *io, void *buffer, ULONG length,
                                BOOLEAN single_entry, const UNICODE_STRING *mask,
                                BOOLEAN restart_scan, FILE_INFORMATION_CLASS class )
{
    int unix_len, ret, used_default;
    char *unix_name;
    struct stat st;

    TRACE("trying optimisation for file %s\n", debugstr_us( mask ));

    unix_len = ntdll_wcstoumbs( 0, mask->Buffer, mask->Length / sizeof(WCHAR), NULL, 0, NULL, NULL );
    if (!(unix_name = RtlAllocateHeap( GetProcessHeap(), 0, unix_len + 1)))
    {
        io->u.Status = STATUS_NO_MEMORY;
        return 0;
    }
    ret = ntdll_wcstoumbs( 0, mask->Buffer, mask->Length / sizeof(WCHAR), unix_name, unix_len,
                           NULL, &used_default );
    if (ret > 0 && !used_default)
    {
        unix_name[ret] = 0;
        if (restart_scan)
        {
            lseek( fd, 0, SEEK_SET );
        }
        else if (lseek( fd, 0, SEEK_CUR ) != 0)
        {
            io->u.Status = STATUS_NO_MORE_FILES;
            ret = 0;
            goto done;
        }

        ret = stat( unix_name, &st );
        if (!ret)
        {
            union file_directory_info *info = append_entry( buffer, io, length, unix_name, NULL, NULL, class );
            if (info)
            {
                info->next = 0;
                if (io->u.Status != STATUS_BUFFER_OVERFLOW) lseek( fd, 1, SEEK_CUR );
            }
            else io->u.Status = STATUS_NO_MORE_FILES;
        }
    }
    else ret = -1;

done:
    RtlFreeHeap( GetProcessHeap(), 0, unix_name );

    TRACE("returning %d\n", ret);

    return ret;
}


/******************************************************************************
 *  NtQueryDirectoryFile	[NTDLL.@]
 *  ZwQueryDirectoryFile	[NTDLL.@]
 */
NTSTATUS WINAPI NtQueryDirectoryFile( HANDLE handle, HANDLE event,
                                      PIO_APC_ROUTINE apc_routine, PVOID apc_context,
                                      PIO_STATUS_BLOCK io,
                                      PVOID buffer, ULONG length,
                                      FILE_INFORMATION_CLASS info_class,
                                      BOOLEAN single_entry,
                                      PUNICODE_STRING mask,
                                      BOOLEAN restart_scan )
{
    int cwd, fd, needs_close;

    TRACE("(%p %p %p %p %p %p 0x%08x 0x%08x 0x%08x %s 0x%08x\n",
          handle, event, apc_routine, apc_context, io, buffer,
          length, info_class, single_entry, debugstr_us(mask),
          restart_scan);

    if (event || apc_routine)
    {
        FIXME( "Unsupported yet option\n" );
        return io->u.Status = STATUS_NOT_IMPLEMENTED;
    }
    switch (info_class)
    {
    case FileDirectoryInformation:
    case FileBothDirectoryInformation:
    case FileFullDirectoryInformation:
    case FileIdBothDirectoryInformation:
    case FileIdFullDirectoryInformation:
        if (length < dir_info_size( info_class, 1 )) return io->u.Status = STATUS_INFO_LENGTH_MISMATCH;
        if (!buffer) return io->u.Status = STATUS_ACCESS_VIOLATION;
        break;
    default:
        FIXME( "Unsupported file info class %d\n", info_class );
        return io->u.Status = STATUS_NOT_IMPLEMENTED;
    }

    if ((io->u.Status = server_get_unix_fd( handle, FILE_LIST_DIRECTORY, &fd, &needs_close, NULL, NULL )) != STATUS_SUCCESS)
        return io->u.Status;

    io->Information = 0;

    RtlRunOnceExecuteOnce( &init_once, init_options, NULL, NULL );

    RtlEnterCriticalSection( &dir_section );

    cwd = open( ".", O_RDONLY );
    if (fchdir( fd ) != -1)
    {
        struct stat st;
        fstat( fd, &st );
        curdir.dev = st.st_dev;
        curdir.ino = st.st_ino;
#ifdef VFAT_IOCTL_READDIR_BOTH
        if ((read_directory_vfat( fd, io, buffer, length, single_entry,
                                  mask, restart_scan, info_class )) != -1) goto done;
#endif
        if (!has_wildcard( mask ) &&
            read_directory_stat( fd, io, buffer, length, single_entry,
                                 mask, restart_scan, info_class ) != -1) goto done;
#ifdef USE_GETDENTS
        if ((read_directory_getdents( fd, io, buffer, length, single_entry,
                                      mask, restart_scan, info_class )) != -1) goto done;
#elif defined HAVE_GETDIRENTRIES
        if ((read_directory_getdirentries( fd, io, buffer, length, single_entry,
                                           mask, restart_scan, info_class )) != -1) goto done;
#endif
        read_directory_readdir( fd, io, buffer, length, single_entry, mask, restart_scan, info_class );

    done:
        if (cwd == -1 || fchdir( cwd ) == -1) chdir( "/" );
    }
    else io->u.Status = FILE_GetNtStatus();

    RtlLeaveCriticalSection( &dir_section );

    if (needs_close) close( fd );
    if (cwd != -1) close( cwd );
    TRACE( "=> %x (%ld)\n", io->u.Status, io->Information );
    return io->u.Status;
}


/***********************************************************************
 *           find_file_in_dir
 *
 * Find a file in a directory the hard way, by doing a case-insensitive search.
 * The file found is appended to unix_name at pos.
 * There must be at least MAX_DIR_ENTRY_LEN+2 chars available at pos.
 */
static NTSTATUS find_file_in_dir( char *unix_name, int pos, const WCHAR *name, int length,
                                  BOOLEAN check_case, BOOLEAN *is_win_dir )
{
    WCHAR buffer[MAX_DIR_ENTRY_LEN];
    UNICODE_STRING str;
    BOOLEAN spaces, is_name_8_dot_3;
    DIR *dir;
    struct dirent *de;
    struct stat st;
    int ret, used_default;

    /* try a shortcut for this directory */

    unix_name[pos++] = '/';
    ret = ntdll_wcstoumbs( 0, name, length, unix_name + pos, MAX_DIR_ENTRY_LEN,
                           NULL, &used_default );
    /* if we used the default char, the Unix name won't round trip properly back to Unicode */
    /* so it cannot match the file we are looking for */
    if (ret >= 0 && !used_default)
    {
        unix_name[pos + ret] = 0;
        if (!stat( unix_name, &st ))
        {
            if (is_win_dir) *is_win_dir = is_same_file( &windir, &st );
            return STATUS_SUCCESS;
        }
    }
    if (check_case) goto not_found;  /* we want an exact match */

    if (pos > 1) unix_name[pos - 1] = 0;
    else unix_name[1] = 0;  /* keep the initial slash */

    /* check if it fits in 8.3 so that we don't look for short names if we won't need them */

    str.Buffer = (WCHAR *)name;
    str.Length = length * sizeof(WCHAR);
    str.MaximumLength = str.Length;
    is_name_8_dot_3 = RtlIsNameLegalDOS8Dot3( &str, NULL, &spaces ) && !spaces;

    if (!is_name_8_dot_3 && !get_dir_case_sensitivity( unix_name )) goto not_found;

    /* now look for it through the directory */

#ifdef VFAT_IOCTL_READDIR_BOTH
    if (is_name_8_dot_3)
    {
        int fd = open( unix_name, O_RDONLY | O_DIRECTORY );
        if (fd != -1)
        {
            KERNEL_DIRENT *kde;

            RtlEnterCriticalSection( &dir_section );
            if ((kde = start_vfat_ioctl( fd )))
            {
                unix_name[pos - 1] = '/';
                while (kde[0].d_reclen)
                {
                    /* make sure names are null-terminated to work around an x86-64 kernel bug */
                    size_t len = min(kde[0].d_reclen, sizeof(kde[0].d_name) - 1 );
                    kde[0].d_name[len] = 0;
                    len = min(kde[1].d_reclen, sizeof(kde[1].d_name) - 1 );
                    kde[1].d_name[len] = 0;

                    if (kde[1].d_name[0])
                    {
                        ret = ntdll_umbstowcs( 0, kde[1].d_name, strlen(kde[1].d_name),
                                               buffer, MAX_DIR_ENTRY_LEN );
                        if (ret == length && !memicmpW( buffer, name, length))
                        {
                            strcpy( unix_name + pos, kde[1].d_name );
                            RtlLeaveCriticalSection( &dir_section );
                            close( fd );
                            goto success;
                        }
                    }
                    ret = ntdll_umbstowcs( 0, kde[0].d_name, strlen(kde[0].d_name),
                                           buffer, MAX_DIR_ENTRY_LEN );
                    if (ret == length && !memicmpW( buffer, name, length))
                    {
                        strcpy( unix_name + pos,
                                kde[1].d_name[0] ? kde[1].d_name : kde[0].d_name );
                        RtlLeaveCriticalSection( &dir_section );
                        close( fd );
                        goto success;
                    }
                    if (ioctl( fd, VFAT_IOCTL_READDIR_BOTH, (long)kde ) == -1)
                    {
                        RtlLeaveCriticalSection( &dir_section );
                        close( fd );
                        goto not_found;
                    }
                }
            }
            RtlLeaveCriticalSection( &dir_section );
            close( fd );
        }
        /* fall through to normal handling */
    }
#endif /* VFAT_IOCTL_READDIR_BOTH */

    if (!(dir = opendir( unix_name )))
    {
        if (errno == ENOENT) return STATUS_OBJECT_PATH_NOT_FOUND;
        else return FILE_GetNtStatus();
    }
    unix_name[pos - 1] = '/';
    str.Buffer = buffer;
    str.MaximumLength = sizeof(buffer);
    while ((de = readdir( dir )))
    {
        ret = ntdll_umbstowcs( 0, de->d_name, strlen(de->d_name), buffer, MAX_DIR_ENTRY_LEN );
        if (ret == length && !memicmpW( buffer, name, length ))
        {
            strcpy( unix_name + pos, de->d_name );
            closedir( dir );
            goto success;
        }

        if (!is_name_8_dot_3) continue;

        str.Length = ret * sizeof(WCHAR);
        if (!RtlIsNameLegalDOS8Dot3( &str, NULL, &spaces ) || spaces)
        {
            WCHAR short_nameW[12];
            ret = hash_short_file_name( &str, short_nameW );
            if (ret == length && !memicmpW( short_nameW, name, length ))
            {
                strcpy( unix_name + pos, de->d_name );
                closedir( dir );
                goto success;
            }
        }
    }
    closedir( dir );

not_found:
    unix_name[pos - 1] = 0;
    return STATUS_OBJECT_PATH_NOT_FOUND;

success:
    if (is_win_dir && !stat( unix_name, &st )) *is_win_dir = is_same_file( &windir, &st );
    return STATUS_SUCCESS;
}


#ifndef _WIN64

static const WCHAR catrootW[] = {'s','y','s','t','e','m','3','2','\\','c','a','t','r','o','o','t',0};
static const WCHAR catroot2W[] = {'s','y','s','t','e','m','3','2','\\','c','a','t','r','o','o','t','2',0};
static const WCHAR driversstoreW[] = {'s','y','s','t','e','m','3','2','\\','d','r','i','v','e','r','s','s','t','o','r','e',0};
static const WCHAR driversetcW[] = {'s','y','s','t','e','m','3','2','\\','d','r','i','v','e','r','s','\\','e','t','c',0};
static const WCHAR logfilesW[] = {'s','y','s','t','e','m','3','2','\\','l','o','g','f','i','l','e','s',0};
static const WCHAR spoolW[] = {'s','y','s','t','e','m','3','2','\\','s','p','o','o','l',0};
static const WCHAR system32W[] = {'s','y','s','t','e','m','3','2',0};
static const WCHAR syswow64W[] = {'s','y','s','w','o','w','6','4',0};
static const WCHAR sysnativeW[] = {'s','y','s','n','a','t','i','v','e',0};
static const WCHAR regeditW[] = {'r','e','g','e','d','i','t','.','e','x','e',0};
static const WCHAR wow_regeditW[] = {'s','y','s','w','o','w','6','4','\\','r','e','g','e','d','i','t','.','e','x','e',0};

static struct
{
    const WCHAR *source;
    const WCHAR *dos_target;
    const char *unix_target;
} redirects[] =
{
    { catrootW, NULL, NULL },
    { catroot2W, NULL, NULL },
    { driversstoreW, NULL, NULL },
    { driversetcW, NULL, NULL },
    { logfilesW, NULL, NULL },
    { spoolW, NULL, NULL },
    { system32W, syswow64W, NULL },
    { sysnativeW, system32W, NULL },
    { regeditW, wow_regeditW, NULL }
};

static unsigned int nb_redirects;


/***********************************************************************
 *           get_redirect_target
 *
 * Find the target unix name for a redirected dir.
 */
static const char *get_redirect_target( const char *windows_dir, const WCHAR *name )
{
    int used_default, len, pos, win_len = strlen( windows_dir );
    char *unix_name, *unix_target = NULL;
    NTSTATUS status;

    if (!(unix_name = RtlAllocateHeap( GetProcessHeap(), 0, win_len + MAX_DIR_ENTRY_LEN + 2 )))
        return NULL;
    memcpy( unix_name, windows_dir, win_len );
    pos = win_len;

    while (*name)
    {
        const WCHAR *end, *next;

        for (end = name; *end; end++) if (IS_SEPARATOR(*end)) break;
        for (next = end; *next; next++) if (!IS_SEPARATOR(*next)) break;

        status = find_file_in_dir( unix_name, pos, name, end - name, FALSE, NULL );
        if (status == STATUS_OBJECT_PATH_NOT_FOUND && !*next)  /* not finding last element is ok */
        {
            len = ntdll_wcstoumbs( 0, name, end - name, unix_name + pos + 1,
                                   MAX_DIR_ENTRY_LEN - (pos - win_len), NULL, &used_default );
            if (len > 0 && !used_default)
            {
                unix_name[pos] = '/';
                pos += len + 1;
                unix_name[pos] = 0;
                break;
            }
        }
        if (status) goto done;
        pos += strlen( unix_name + pos );
        name = next;
    }

    if ((unix_target = RtlAllocateHeap( GetProcessHeap(), 0, pos - win_len )))
        memcpy( unix_target, unix_name + win_len + 1, pos - win_len );

done:
    RtlFreeHeap( GetProcessHeap(), 0, unix_name );
    return unix_target;
}


/***********************************************************************
 *           init_redirects
 */
static void init_redirects(void)
{
    UNICODE_STRING nt_name;
    ANSI_STRING unix_name;
    NTSTATUS status;
    struct stat st;
    unsigned int i;

    if (!RtlDosPathNameToNtPathName_U( user_shared_data->NtSystemRoot, &nt_name, NULL, NULL ))
    {
        ERR( "can't convert %s\n", debugstr_w(user_shared_data->NtSystemRoot) );
        return;
    }
    status = wine_nt_to_unix_file_name( &nt_name, &unix_name, FILE_OPEN_IF, FALSE );
    RtlFreeUnicodeString( &nt_name );
    if (status)
    {
        ERR( "cannot open %s (%x)\n", debugstr_w(user_shared_data->NtSystemRoot), status );
        return;
    }
    if (!stat( unix_name.Buffer, &st ))
    {
        windir.dev = st.st_dev;
        windir.ino = st.st_ino;
        nb_redirects = sizeof(redirects) / sizeof(redirects[0]);
        for (i = 0; i < nb_redirects; i++)
        {
            if (!redirects[i].dos_target) continue;
            redirects[i].unix_target = get_redirect_target( unix_name.Buffer, redirects[i].dos_target );
            TRACE( "%s -> %s\n", debugstr_w(redirects[i].source), redirects[i].unix_target );
        }
    }
    RtlFreeAnsiString( &unix_name );

}


/***********************************************************************
 *           match_redirect
 *
 * Check if path matches a redirect name. If yes, return matched length.
 */
static int match_redirect( const WCHAR *path, int len, const WCHAR *redir, BOOLEAN check_case )
{
    int i = 0;

    while (i < len && *redir)
    {
        if (IS_SEPARATOR(path[i]))
        {
            if (*redir++ != '\\') return 0;
            while (i < len && IS_SEPARATOR(path[i])) i++;
            continue;  /* move on to next path component */
        }
        else if (check_case)
        {
            if (path[i] != *redir) return 0;
        }
        else
        {
            if (tolowerW(path[i]) != tolowerW(*redir)) return 0;
        }
        i++;
        redir++;
    }
    if (*redir) return 0;
    if (i < len && !IS_SEPARATOR(path[i])) return 0;
    while (i < len && IS_SEPARATOR(path[i])) i++;
    return i;
}


/***********************************************************************
 *           get_redirect_path
 *
 * Retrieve the Unix path corresponding to a redirected path if any.
 */
static int get_redirect_path( char *unix_name, int pos, const WCHAR *name, int length, BOOLEAN check_case )
{
    unsigned int i;
    int len;

    for (i = 0; i < nb_redirects; i++)
    {
        if ((len = match_redirect( name, length, redirects[i].source, check_case )))
        {
            if (!redirects[i].unix_target) break;
            unix_name[pos++] = '/';
            strcpy( unix_name + pos, redirects[i].unix_target );
            return len;
        }
    }
    return 0;
}

#else  /* _WIN64 */

/* there are no redirects on 64-bit */

static const unsigned int nb_redirects = 0;

static int get_redirect_path( char *unix_name, int pos, const WCHAR *name, int length, BOOLEAN check_case )
{
    return 0;
}

#endif

/***********************************************************************
 *           DIR_init_windows_dir
 */
void DIR_init_windows_dir( const WCHAR *win, const WCHAR *sys )
{
    /* FIXME: should probably store paths as NT file names */

    RtlCreateUnicodeString( &system_dir, sys );

#ifndef _WIN64
    if (is_wow64) init_redirects();
#endif
}


/******************************************************************************
 *           get_dos_device
 *
 * Get the Unix path of a DOS device.
 */
static NTSTATUS get_dos_device( const WCHAR *name, UINT name_len, ANSI_STRING *unix_name_ret )
{
    const char *config_dir = wine_get_config_dir();
    struct stat st;
    char *unix_name, *new_name, *dev;
    unsigned int i;
    int unix_len;

    /* make sure the device name is ASCII */
    for (i = 0; i < name_len; i++)
        if (name[i] <= 32 || name[i] >= 127) return STATUS_BAD_DEVICE_TYPE;

    unix_len = strlen(config_dir) + sizeof("/dosdevices/") + name_len + 1;

    if (!(unix_name = RtlAllocateHeap( GetProcessHeap(), 0, unix_len )))
        return STATUS_NO_MEMORY;

    strcpy( unix_name, config_dir );
    strcat( unix_name, "/dosdevices/" );
    dev = unix_name + strlen(unix_name);

    for (i = 0; i < name_len; i++) dev[i] = (char)tolowerW(name[i]);
    dev[i] = 0;

    /* special case for drive devices */
    if (name_len == 2 && dev[1] == ':')
    {
        dev[i++] = ':';
        dev[i] = 0;
    }

    for (;;)
    {
        if (!stat( unix_name, &st ))
        {
            TRACE( "%s -> %s\n", debugstr_wn(name,name_len), debugstr_a(unix_name) );
            unix_name_ret->Buffer = unix_name;
            unix_name_ret->Length = strlen(unix_name);
            unix_name_ret->MaximumLength = unix_len;
            return STATUS_SUCCESS;
        }
        if (!dev) break;

        /* now try some defaults for it */
        if (!strcmp( dev, "aux" ))
        {
            strcpy( dev, "com1" );
            continue;
        }
        if (!strcmp( dev, "prn" ))
        {
            strcpy( dev, "lpt1" );
            continue;
        }
        if (!strcmp( dev, "nul" ))
        {
            strcpy( unix_name, "/dev/null" );
            dev = NULL; /* last try */
            continue;
        }

        new_name = NULL;
        if (dev[1] == ':' && dev[2] == ':')  /* drive device */
        {
            dev[2] = 0;  /* remove last ':' to get the drive mount point symlink */
            new_name = get_default_drive_device( unix_name );
        }
        else if (!strncmp( dev, "com", 3 )) new_name = get_default_com_device( atoi(dev + 3 ));
        else if (!strncmp( dev, "lpt", 3 )) new_name = get_default_lpt_device( atoi(dev + 3 ));

        if (!new_name) break;

        RtlFreeHeap( GetProcessHeap(), 0, unix_name );
        unix_name = new_name;
        unix_len = strlen(unix_name) + 1;
        dev = NULL; /* last try */
    }
    RtlFreeHeap( GetProcessHeap(), 0, unix_name );
    return STATUS_BAD_DEVICE_TYPE;
}


/* return the length of the DOS namespace prefix if any */
static inline int get_dos_prefix_len( const UNICODE_STRING *name )
{
    static const WCHAR nt_prefixW[] = {'\\','?','?','\\'};
    static const WCHAR dosdev_prefixW[] = {'\\','D','o','s','D','e','v','i','c','e','s','\\'};

    if (name->Length > sizeof(nt_prefixW) &&
        !memcmp( name->Buffer, nt_prefixW, sizeof(nt_prefixW) ))
        return sizeof(nt_prefixW) / sizeof(WCHAR);

    if (name->Length > sizeof(dosdev_prefixW) &&
        !memicmpW( name->Buffer, dosdev_prefixW, sizeof(dosdev_prefixW)/sizeof(WCHAR) ))
        return sizeof(dosdev_prefixW) / sizeof(WCHAR);

    return 0;
}


/******************************************************************************
 *           find_file_id
 *
 * Recursively search directories from the dir queue for a given inode.
 */
static NTSTATUS find_file_id( ANSI_STRING *unix_name, ULONGLONG file_id, dev_t dev )
{
    unsigned int pos;
    DIR *dir;
    struct dirent *de;
    NTSTATUS status;
    struct stat st;

    while (!(status = next_dir_in_queue( unix_name->Buffer )))
    {
        if (!(dir = opendir( unix_name->Buffer ))) continue;
        TRACE( "searching %s for %s\n", unix_name->Buffer, wine_dbgstr_longlong(file_id) );
        pos = strlen( unix_name->Buffer );
        if (pos + MAX_DIR_ENTRY_LEN >= unix_name->MaximumLength/sizeof(WCHAR))
        {
            char *new = RtlReAllocateHeap( GetProcessHeap(), 0, unix_name->Buffer,
                                           unix_name->MaximumLength * 2 );
            if (!new)
            {
                closedir( dir );
                return STATUS_NO_MEMORY;
            }
            unix_name->MaximumLength *= 2;
            unix_name->Buffer = new;
        }
        unix_name->Buffer[pos++] = '/';
        while ((de = readdir( dir )))
        {
            if (!strcmp( de->d_name, "." ) || !strcmp( de->d_name, ".." )) continue;
            strcpy( unix_name->Buffer + pos, de->d_name );
            if (lstat( unix_name->Buffer, &st ) == -1) continue;
            if (st.st_dev != dev) continue;
            if (st.st_ino == file_id)
            {
                closedir( dir );
                return STATUS_SUCCESS;
            }
            if (!S_ISDIR( st.st_mode )) continue;
            if ((status = add_dir_to_queue( unix_name->Buffer )) != STATUS_SUCCESS)
            {
                closedir( dir );
                return status;
            }
        }
        closedir( dir );
    }
    return status;
}


/******************************************************************************
 *           file_id_to_unix_file_name
 *
 * Lookup a file from its file id instead of its name.
 */
NTSTATUS file_id_to_unix_file_name( const OBJECT_ATTRIBUTES *attr, ANSI_STRING *unix_name )
{
    enum server_fd_type type;
    int old_cwd, root_fd, needs_close;
    NTSTATUS status;
    ULONGLONG file_id;
    struct stat st, root_st;

    if (attr->ObjectName->Length != sizeof(ULONGLONG)) return STATUS_OBJECT_PATH_SYNTAX_BAD;
    if (!attr->RootDirectory) return STATUS_INVALID_PARAMETER;
    memcpy( &file_id, attr->ObjectName->Buffer, sizeof(file_id) );

    unix_name->MaximumLength = 2 * MAX_DIR_ENTRY_LEN + 4;
    if (!(unix_name->Buffer = RtlAllocateHeap( GetProcessHeap(), 0, unix_name->MaximumLength )))
        return STATUS_NO_MEMORY;
    strcpy( unix_name->Buffer, "." );

    if ((status = server_get_unix_fd( attr->RootDirectory, 0, &root_fd, &needs_close, &type, NULL )))
        goto done;

    if (type != FD_TYPE_DIR)
    {
        status = STATUS_OBJECT_TYPE_MISMATCH;
        goto done;
    }

    fstat( root_fd, &root_st );
    if (root_st.st_ino == file_id)  /* shortcut for "." */
    {
        status = STATUS_SUCCESS;
        goto done;
    }

    RtlEnterCriticalSection( &dir_section );
    if ((old_cwd = open( ".", O_RDONLY )) != -1 && fchdir( root_fd ) != -1)
    {
        /* shortcut for ".." */
        if (!stat( "..", &st ) && st.st_dev == root_st.st_dev && st.st_ino == file_id)
        {
            strcpy( unix_name->Buffer, ".." );
            status = STATUS_SUCCESS;
        }
        else
        {
            status = add_dir_to_queue( "." );
            if (!status)
                status = find_file_id( unix_name, file_id, root_st.st_dev );
            if (!status)  /* get rid of "./" prefix */
                memmove( unix_name->Buffer, unix_name->Buffer + 2, strlen(unix_name->Buffer) - 1 );
            flush_dir_queue();
        }
        if (fchdir( old_cwd ) == -1) chdir( "/" );
    }
    else status = FILE_GetNtStatus();
    RtlLeaveCriticalSection( &dir_section );
    if (old_cwd != -1) close( old_cwd );

done:
    if (status == STATUS_SUCCESS)
    {
        TRACE( "%s -> %s\n", wine_dbgstr_longlong(file_id), debugstr_a(unix_name->Buffer) );
        unix_name->Length = strlen( unix_name->Buffer );
    }
    else
    {
        TRACE( "%s not found in dir %p\n", wine_dbgstr_longlong(file_id), attr->RootDirectory );
        RtlFreeHeap( GetProcessHeap(), 0, unix_name->Buffer );
    }
    if (needs_close) close( root_fd );
    return status;
}


/******************************************************************************
 *           lookup_unix_name
 *
 * Helper for nt_to_unix_file_name
 */
static NTSTATUS lookup_unix_name( const WCHAR *name, int name_len, char **buffer, int unix_len, int pos,
                                  UINT disposition, BOOLEAN check_case )
{
    NTSTATUS status;
    int ret, used_default, len;
    struct stat st;
    char *unix_name = *buffer;
    const BOOL redirect = nb_redirects && ntdll_get_thread_data()->wow64_redir;

    /* try a shortcut first */

    ret = ntdll_wcstoumbs( 0, name, name_len, unix_name + pos, unix_len - pos - 1,
                           NULL, &used_default );

    while (name_len && IS_SEPARATOR(*name))
    {
        name++;
        name_len--;
    }

    if (ret >= 0 && !used_default)  /* if we used the default char the name didn't convert properly */
    {
        char *p;
        unix_name[pos + ret] = 0;
        for (p = unix_name + pos ; *p; p++) if (*p == '\\') *p = '/';
        if (!redirect || (!strstr( unix_name, "/windows/") && strncmp( unix_name, "windows/", 8 )))
        {
            if (!stat( unix_name, &st ))
            {
                /* creation fails with STATUS_ACCESS_DENIED for the root of the drive */
                if (disposition == FILE_CREATE)
                    return name_len ? STATUS_OBJECT_NAME_COLLISION : STATUS_ACCESS_DENIED;
                return STATUS_SUCCESS;
            }
        }
    }

    if (!name_len)  /* empty name -> drive root doesn't exist */
        return STATUS_OBJECT_PATH_NOT_FOUND;
    if (check_case && !redirect && (disposition == FILE_OPEN || disposition == FILE_OVERWRITE))
        return STATUS_OBJECT_NAME_NOT_FOUND;

    /* now do it component by component */

    while (name_len)
    {
        const WCHAR *end, *next;
        BOOLEAN is_win_dir = FALSE;

        end = name;
        while (end < name + name_len && !IS_SEPARATOR(*end)) end++;
        next = end;
        while (next < name + name_len && IS_SEPARATOR(*next)) next++;
        name_len -= next - name;

        /* grow the buffer if needed */

        if (unix_len - pos < MAX_DIR_ENTRY_LEN + 2)
        {
            char *new_name;
            unix_len += 2 * MAX_DIR_ENTRY_LEN;
            if (!(new_name = RtlReAllocateHeap( GetProcessHeap(), 0, unix_name, unix_len )))
                return STATUS_NO_MEMORY;
            unix_name = *buffer = new_name;
        }

        status = find_file_in_dir( unix_name, pos, name, end - name,
                                   check_case, redirect ? &is_win_dir : NULL );

        /* if this is the last element, not finding it is not necessarily fatal */
        if (!name_len)
        {
            if (status == STATUS_OBJECT_PATH_NOT_FOUND)
            {
                status = STATUS_OBJECT_NAME_NOT_FOUND;
                if (disposition != FILE_OPEN && disposition != FILE_OVERWRITE)
                {
                    ret = ntdll_wcstoumbs( 0, name, end - name, unix_name + pos + 1,
                                           MAX_DIR_ENTRY_LEN, NULL, &used_default );
                    if (ret > 0 && !used_default)
                    {
                        unix_name[pos] = '/';
                        unix_name[pos + 1 + ret] = 0;
                        status = STATUS_NO_SUCH_FILE;
                        break;
                    }
                }
            }
            else if (status == STATUS_SUCCESS && disposition == FILE_CREATE)
            {
                status = STATUS_OBJECT_NAME_COLLISION;
            }
        }

        if (status != STATUS_SUCCESS) break;

        pos += strlen( unix_name + pos );
        name = next;

        if (is_win_dir && (len = get_redirect_path( unix_name, pos, name, name_len, check_case )))
        {
            name += len;
            name_len -= len;
            pos += strlen( unix_name + pos );
            TRACE( "redirecting -> %s + %s\n", debugstr_a(unix_name), debugstr_w(name) );
        }
    }

    return status;
}


/******************************************************************************
 *           nt_to_unix_file_name_attr
 */
NTSTATUS nt_to_unix_file_name_attr( const OBJECT_ATTRIBUTES *attr, ANSI_STRING *unix_name_ret,
                                    UINT disposition )
{
    static const WCHAR invalid_charsW[] = { INVALID_NT_CHARS, 0 };
    enum server_fd_type type;
    int old_cwd, root_fd, needs_close;
    const WCHAR *name, *p;
    char *unix_name;
    int name_len, unix_len;
    NTSTATUS status;
    BOOLEAN check_case = !(attr->Attributes & OBJ_CASE_INSENSITIVE);

    if (!attr->RootDirectory)  /* without root dir fall back to normal lookup */
        return wine_nt_to_unix_file_name( attr->ObjectName, unix_name_ret, disposition, check_case );

    name     = attr->ObjectName->Buffer;
    name_len = attr->ObjectName->Length / sizeof(WCHAR);

    if (name_len && IS_SEPARATOR(name[0])) return STATUS_INVALID_PARAMETER;

    /* check for invalid characters */
    for (p = name; p < name + name_len; p++)
        if (*p < 32 || strchrW( invalid_charsW, *p )) return STATUS_OBJECT_NAME_INVALID;

    unix_len = ntdll_wcstoumbs( 0, name, name_len, NULL, 0, NULL, NULL );
    unix_len += MAX_DIR_ENTRY_LEN + 3;
    if (!(unix_name = RtlAllocateHeap( GetProcessHeap(), 0, unix_len )))
        return STATUS_NO_MEMORY;
    unix_name[0] = '.';

    if (!(status = server_get_unix_fd( attr->RootDirectory, 0, &root_fd, &needs_close, &type, NULL )))
    {
        if (type != FD_TYPE_DIR)
        {
            if (needs_close) close( root_fd );
            status = STATUS_BAD_DEVICE_TYPE;
        }
        else
        {
            RtlEnterCriticalSection( &dir_section );
            if ((old_cwd = open( ".", O_RDONLY )) != -1 && fchdir( root_fd ) != -1)
            {
                status = lookup_unix_name( name, name_len, &unix_name, unix_len, 1,
                                           disposition, check_case );
                if (fchdir( old_cwd ) == -1) chdir( "/" );
            }
            else status = FILE_GetNtStatus();
            RtlLeaveCriticalSection( &dir_section );
            if (old_cwd != -1) close( old_cwd );
            if (needs_close) close( root_fd );
        }
    }
    else if (status == STATUS_OBJECT_TYPE_MISMATCH) status = STATUS_BAD_DEVICE_TYPE;

    if (status == STATUS_SUCCESS || status == STATUS_NO_SUCH_FILE)
    {
        TRACE( "%s -> %s\n", debugstr_us(attr->ObjectName), debugstr_a(unix_name) );
        unix_name_ret->Buffer = unix_name;
        unix_name_ret->Length = strlen(unix_name);
        unix_name_ret->MaximumLength = unix_len;
    }
    else
    {
        TRACE( "%s not found in %s\n", debugstr_w(name), unix_name );
        RtlFreeHeap( GetProcessHeap(), 0, unix_name );
    }
    return status;
}


/******************************************************************************
 *           wine_nt_to_unix_file_name  (NTDLL.@) Not a Windows API
 *
 * Convert a file name from NT namespace to Unix namespace.
 *
 * If disposition is not FILE_OPEN or FILE_OVERWRITE, the last path
 * element doesn't have to exist; in that case STATUS_NO_SUCH_FILE is
 * returned, but the unix name is still filled in properly.
 */
NTSTATUS CDECL wine_nt_to_unix_file_name( const UNICODE_STRING *nameW, ANSI_STRING *unix_name_ret,
                                          UINT disposition, BOOLEAN check_case )
{
    static const WCHAR unixW[] = {'u','n','i','x'};
    static const WCHAR invalid_charsW[] = { INVALID_NT_CHARS, 0 };

    NTSTATUS status = STATUS_SUCCESS;
    const char *config_dir = wine_get_config_dir();
    const WCHAR *name, *p;
    struct stat st;
    char *unix_name;
    int pos, ret, name_len, unix_len, prefix_len, used_default;
    WCHAR prefix[MAX_DIR_ENTRY_LEN];
    BOOLEAN is_unix = FALSE;

    name     = nameW->Buffer;
    name_len = nameW->Length / sizeof(WCHAR);

    if (!name_len || !IS_SEPARATOR(name[0])) return STATUS_OBJECT_PATH_SYNTAX_BAD;

    if (!(pos = get_dos_prefix_len( nameW )))
        return STATUS_BAD_DEVICE_TYPE;  /* no DOS prefix, assume NT native name */

    name += pos;
    name_len -= pos;

    /* check for sub-directory */
    for (pos = 0; pos < name_len; pos++)
    {
        if (IS_SEPARATOR(name[pos])) break;
        if (name[pos] < 32 || strchrW( invalid_charsW, name[pos] ))
            return STATUS_OBJECT_NAME_INVALID;
    }
    if (pos > MAX_DIR_ENTRY_LEN)
        return STATUS_OBJECT_NAME_INVALID;

    if (pos == name_len)  /* no subdir, plain DOS device */
        return get_dos_device( name, name_len, unix_name_ret );

    for (prefix_len = 0; prefix_len < pos; prefix_len++)
        prefix[prefix_len] = tolowerW(name[prefix_len]);

    name += prefix_len;
    name_len -= prefix_len;

    /* check for invalid characters (all chars except 0 are valid for unix) */
    is_unix = (prefix_len == 4 && !memcmp( prefix, unixW, sizeof(unixW) ));
    if (is_unix)
    {
        for (p = name; p < name + name_len; p++)
            if (!*p) return STATUS_OBJECT_NAME_INVALID;
        check_case = TRUE;
    }
    else
    {
        for (p = name; p < name + name_len; p++)
            if (*p < 32 || strchrW( invalid_charsW, *p )) return STATUS_OBJECT_NAME_INVALID;
    }

    unix_len = ntdll_wcstoumbs( 0, prefix, prefix_len, NULL, 0, NULL, NULL );
    unix_len += ntdll_wcstoumbs( 0, name, name_len, NULL, 0, NULL, NULL );
    unix_len += MAX_DIR_ENTRY_LEN + 3;
    unix_len += strlen(config_dir) + sizeof("/dosdevices/");
    if (!(unix_name = RtlAllocateHeap( GetProcessHeap(), 0, unix_len )))
        return STATUS_NO_MEMORY;
    strcpy( unix_name, config_dir );
    strcat( unix_name, "/dosdevices/" );
    pos = strlen(unix_name);

    ret = ntdll_wcstoumbs( 0, prefix, prefix_len, unix_name + pos, unix_len - pos - 1,
                           NULL, &used_default );
    if (!ret || used_default)
    {
        RtlFreeHeap( GetProcessHeap(), 0, unix_name );
        return STATUS_OBJECT_NAME_INVALID;
    }
    pos += ret;

    /* check if prefix exists (except for DOS drives to avoid extra stat calls) */

    if (prefix_len != 2 || prefix[1] != ':')
    {
        unix_name[pos] = 0;
        if (lstat( unix_name, &st ) == -1 && errno == ENOENT)
        {
            if (!is_unix)
            {
                RtlFreeHeap( GetProcessHeap(), 0, unix_name );
                return STATUS_BAD_DEVICE_TYPE;
            }
            pos = 0;  /* fall back to unix root */
        }
    }

    status = lookup_unix_name( name, name_len, &unix_name, unix_len, pos, disposition, check_case );
    if (status == STATUS_SUCCESS || status == STATUS_NO_SUCH_FILE)
    {
        TRACE( "%s -> %s\n", debugstr_us(nameW), debugstr_a(unix_name) );
        unix_name_ret->Buffer = unix_name;
        unix_name_ret->Length = strlen(unix_name);
        unix_name_ret->MaximumLength = unix_len;
    }
    else
    {
        TRACE( "%s not found in %s\n", debugstr_w(name), unix_name );
        RtlFreeHeap( GetProcessHeap(), 0, unix_name );
    }
    return status;
}


/******************************************************************
 *		RtlWow64EnableFsRedirection   (NTDLL.@)
 */
NTSTATUS WINAPI RtlWow64EnableFsRedirection( BOOLEAN enable )
{
    if (!is_wow64) return STATUS_NOT_IMPLEMENTED;
    ntdll_get_thread_data()->wow64_redir = enable;
    return STATUS_SUCCESS;
}


/******************************************************************
 *		RtlWow64EnableFsRedirectionEx   (NTDLL.@)
 */
NTSTATUS WINAPI RtlWow64EnableFsRedirectionEx( ULONG disable, ULONG *old_value )
{
    if (!is_wow64) return STATUS_NOT_IMPLEMENTED;
    if (((ULONG_PTR)old_value >> 16) == 0) return STATUS_ACCESS_VIOLATION;

    *old_value = !ntdll_get_thread_data()->wow64_redir;
    ntdll_get_thread_data()->wow64_redir = !disable;
    return STATUS_SUCCESS;
}


/******************************************************************
 *		RtlDoesFileExists_U   (NTDLL.@)
 */
BOOLEAN WINAPI RtlDoesFileExists_U(LPCWSTR file_name)
{
    UNICODE_STRING nt_name;
    FILE_BASIC_INFORMATION basic_info;
    OBJECT_ATTRIBUTES attr;
    BOOLEAN ret;

    if (!RtlDosPathNameToNtPathName_U( file_name, &nt_name, NULL, NULL )) return FALSE;

    attr.Length = sizeof(attr);
    attr.RootDirectory = 0;
    attr.ObjectName = &nt_name;
    attr.Attributes = OBJ_CASE_INSENSITIVE;
    attr.SecurityDescriptor = NULL;
    attr.SecurityQualityOfService = NULL;

    ret = NtQueryAttributesFile(&attr, &basic_info) == STATUS_SUCCESS;

    RtlFreeUnicodeString( &nt_name );
    return ret;
}


/***********************************************************************
 *           DIR_unmount_device
 *
 * Unmount the specified device.
 */
NTSTATUS DIR_unmount_device( HANDLE handle )
{
    NTSTATUS status;
    int unix_fd, needs_close;

    if (!(status = server_get_unix_fd( handle, 0, &unix_fd, &needs_close, NULL, NULL )))
    {
        struct stat st;
        char *mount_point = NULL;

        if (fstat( unix_fd, &st ) == -1 || !is_valid_mounted_device( &st ))
            status = STATUS_INVALID_PARAMETER;
        else
        {
            if ((mount_point = get_device_mount_point( st.st_rdev )))
            {
#ifdef __APPLE__
                static const char umount[] = "diskutil unmount >/dev/null 2>&1 ";
#else
                static const char umount[] = "umount >/dev/null 2>&1 ";
#endif
                char *cmd = RtlAllocateHeap( GetProcessHeap(), 0, strlen(mount_point)+sizeof(umount));
                if (cmd)
                {
                    strcpy( cmd, umount );
                    strcat( cmd, mount_point );
                    system( cmd );
                    RtlFreeHeap( GetProcessHeap(), 0, cmd );
#ifdef linux
                    /* umount will fail to release the loop device since we still have
                       a handle to it, so we release it here */
                    if (major(st.st_rdev) == LOOP_MAJOR) ioctl( unix_fd, 0x4c01 /*LOOP_CLR_FD*/, 0 );
#endif
                }
                RtlFreeHeap( GetProcessHeap(), 0, mount_point );
            }
        }
        if (needs_close) close( unix_fd );
    }
    return status;
}


/******************************************************************************
 *           DIR_get_unix_cwd
 *
 * Retrieve the Unix name of the current directory; helper for wine_unix_to_nt_file_name.
 * Returned value must be freed by caller.
 */
NTSTATUS DIR_get_unix_cwd( char **cwd )
{
    int old_cwd, unix_fd, needs_close;
    CURDIR *curdir;
    HANDLE handle;
    NTSTATUS status;

    RtlAcquirePebLock();

    if (NtCurrentTeb()->Tib.SubSystemTib)  /* FIXME: hack */
        curdir = &((WIN16_SUBSYSTEM_TIB *)NtCurrentTeb()->Tib.SubSystemTib)->curdir;
    else
        curdir = &NtCurrentTeb()->Peb->ProcessParameters->CurrentDirectory;

    if (!(handle = curdir->Handle))
    {
        UNICODE_STRING dirW;
        OBJECT_ATTRIBUTES attr;
        IO_STATUS_BLOCK io;

        if (!RtlDosPathNameToNtPathName_U( curdir->DosPath.Buffer, &dirW, NULL, NULL ))
        {
            status = STATUS_OBJECT_NAME_INVALID;
            goto done;
        }
        attr.Length = sizeof(attr);
        attr.RootDirectory = 0;
        attr.Attributes = OBJ_CASE_INSENSITIVE;
        attr.ObjectName = &dirW;
        attr.SecurityDescriptor = NULL;
        attr.SecurityQualityOfService = NULL;

        status = NtOpenFile( &handle, 0, &attr, &io, 0,
                             FILE_DIRECTORY_FILE | FILE_SYNCHRONOUS_IO_NONALERT );
        RtlFreeUnicodeString( &dirW );
        if (status != STATUS_SUCCESS) goto done;
    }

    if ((status = server_get_unix_fd( handle, 0, &unix_fd, &needs_close, NULL, NULL )) == STATUS_SUCCESS)
    {
        RtlEnterCriticalSection( &dir_section );

        if ((old_cwd = open(".", O_RDONLY)) != -1 && fchdir( unix_fd ) != -1)
        {
            unsigned int size = 512;

            for (;;)
            {
                if (!(*cwd = RtlAllocateHeap( GetProcessHeap(), 0, size )))
                {
                    status = STATUS_NO_MEMORY;
                    break;
                }
                if (getcwd( *cwd, size )) break;
                RtlFreeHeap( GetProcessHeap(), 0, *cwd );
                if (errno != ERANGE)
                {
                    status = STATUS_OBJECT_PATH_INVALID;
                    break;
                }
                size *= 2;
            }
            if (fchdir( old_cwd ) == -1) chdir( "/" );
        }
        else status = FILE_GetNtStatus();

        RtlLeaveCriticalSection( &dir_section );
        if (old_cwd != -1) close( old_cwd );
        if (needs_close) close( unix_fd );
    }
    if (!curdir->Handle) NtClose( handle );

done:
    RtlReleasePebLock();
    return status;
}

struct read_changes_info
{
    HANDLE FileHandle;
    PVOID Buffer;
    ULONG BufferSize;
    PIO_APC_ROUTINE apc;
    void           *apc_arg;
};

/* callback for ioctl user APC */
static void WINAPI read_changes_user_apc( void *arg, IO_STATUS_BLOCK *io, ULONG reserved )
{
    struct read_changes_info *info = arg;
    if (info->apc) info->apc( info->apc_arg, io, reserved );
    RtlFreeHeap( GetProcessHeap(), 0, info );
}

static NTSTATUS read_changes_apc( void *user, PIO_STATUS_BLOCK iosb, NTSTATUS status, void **apc )
{
    struct read_changes_info *info = user;
    char data[PATH_MAX];
    NTSTATUS ret;
    int size;

    SERVER_START_REQ( read_change )
    {
        req->handle = wine_server_obj_handle( info->FileHandle );
        wine_server_set_reply( req, data, PATH_MAX );
        ret = wine_server_call( req );
        size = wine_server_reply_size( reply );
    }
    SERVER_END_REQ;

    if (ret == STATUS_SUCCESS && info->Buffer)
    {
        PFILE_NOTIFY_INFORMATION pfni = info->Buffer;
        int i, left = info->BufferSize;
        DWORD *last_entry_offset = NULL;
        struct filesystem_event *event = (struct filesystem_event*)data;

        while (size && left >= sizeof(*pfni))
        {
            /* convert to an NT style path */
            for (i=0; i<event->len; i++)
                if (event->name[i] == '/')
                    event->name[i] = '\\';

            pfni->Action = event->action;
            pfni->FileNameLength = ntdll_umbstowcs( 0, event->name, event->len, pfni->FileName,
                    (left - offsetof(FILE_NOTIFY_INFORMATION, FileName)) / sizeof(WCHAR));
            last_entry_offset = &pfni->NextEntryOffset;

            if(pfni->FileNameLength == -1 || pfni->FileNameLength == -2)
                break;

            i = offsetof(FILE_NOTIFY_INFORMATION, FileName[pfni->FileNameLength]);
            pfni->FileNameLength *= sizeof(WCHAR);
            pfni->NextEntryOffset = i;
            pfni = (FILE_NOTIFY_INFORMATION*)((char*)pfni + i);
            left -= i;

            i = (offsetof(struct filesystem_event, name[event->len])
                    + sizeof(int)-1) / sizeof(int) * sizeof(int);
            event = (struct filesystem_event*)((char*)event + i);
            size -= i;
        }

        if (size)
        {
            ret = STATUS_NOTIFY_ENUM_DIR;
            size = 0;
        }
        else
        {
            *last_entry_offset = 0;
            size = info->BufferSize - left;
        }
    }
    else
    {
        ret = STATUS_NOTIFY_ENUM_DIR;
        size = 0;
    }

    iosb->u.Status = ret;
    iosb->Information = size;
    *apc = read_changes_user_apc;
    return ret;
}

#define FILE_NOTIFY_ALL        (  \
 FILE_NOTIFY_CHANGE_FILE_NAME   | \
 FILE_NOTIFY_CHANGE_DIR_NAME    | \
 FILE_NOTIFY_CHANGE_ATTRIBUTES  | \
 FILE_NOTIFY_CHANGE_SIZE        | \
 FILE_NOTIFY_CHANGE_LAST_WRITE  | \
 FILE_NOTIFY_CHANGE_LAST_ACCESS | \
 FILE_NOTIFY_CHANGE_CREATION    | \
 FILE_NOTIFY_CHANGE_SECURITY   )

/******************************************************************************
 *  NtNotifyChangeDirectoryFile [NTDLL.@]
 */
NTSTATUS WINAPI
NtNotifyChangeDirectoryFile( HANDLE FileHandle, HANDLE Event,
        PIO_APC_ROUTINE ApcRoutine, PVOID ApcContext,
        PIO_STATUS_BLOCK IoStatusBlock, PVOID Buffer,
        ULONG BufferSize, ULONG CompletionFilter, BOOLEAN WatchTree )
{
    struct read_changes_info *info;
    NTSTATUS status;
    ULONG_PTR cvalue = ApcRoutine ? 0 : (ULONG_PTR)ApcContext;

    TRACE("%p %p %p %p %p %p %u %u %d\n",
          FileHandle, Event, ApcRoutine, ApcContext, IoStatusBlock,
          Buffer, BufferSize, CompletionFilter, WatchTree );

    if (!IoStatusBlock)
        return STATUS_ACCESS_VIOLATION;

    if (CompletionFilter == 0 || (CompletionFilter & ~FILE_NOTIFY_ALL))
        return STATUS_INVALID_PARAMETER;

    info = RtlAllocateHeap( GetProcessHeap(), 0, sizeof *info );
    if (!info)
        return STATUS_NO_MEMORY;

    info->FileHandle = FileHandle;
    info->Buffer     = Buffer;
    info->BufferSize = BufferSize;
    info->apc        = ApcRoutine;
    info->apc_arg    = ApcContext;

    SERVER_START_REQ( read_directory_changes )
    {
        req->filter     = CompletionFilter;
        req->want_data  = (Buffer != NULL);
        req->subtree    = WatchTree;
        req->async.handle   = wine_server_obj_handle( FileHandle );
        req->async.callback = wine_server_client_ptr( read_changes_apc );
        req->async.iosb     = wine_server_client_ptr( IoStatusBlock );
        req->async.arg      = wine_server_client_ptr( info );
        req->async.event    = wine_server_obj_handle( Event );
        req->async.cvalue   = cvalue;
        status = wine_server_call( req );
    }
    SERVER_END_REQ;

    if (status != STATUS_PENDING)
        RtlFreeHeap( GetProcessHeap(), 0, info );

    return status;
}