Move block drivers into their own directory

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 0 insertions, 2855 deletions

diff --git a/block-vvfat.c b/block-vvfat.c
deleted file mode 100644
index 2a8feb38d8..0000000000
--- a/block-vvfat.c
+++ /dev/null
@@ -1,2855 +0,0 @@
-/* vim:set shiftwidth=4 ts=8: */
-/*
- * QEMU Block driver for virtual VFAT (shadows a local directory)
- *
- * Copyright (c) 2004,2005 Johannes E. Schindelin
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-#include <sys/stat.h>
-#include <dirent.h>
-#include "qemu-common.h"
-#include "block_int.h"
-#include "module.h"
-
-#ifndef S_IWGRP
-#define S_IWGRP 0
-#endif
-#ifndef S_IWOTH
-#define S_IWOTH 0
-#endif
-
-/* TODO: add ":bootsector=blabla.img:" */
-/* LATER TODO: add automatic boot sector generation from
-    BOOTEASY.ASM and Ranish Partition Manager
-    Note that DOS assumes the system files to be the first files in the
-    file system (test if the boot sector still relies on that fact)! */
-/* MAYBE TODO: write block-visofs.c */
-/* TODO: call try_commit() only after a timeout */
-
-/* #define DEBUG */
-
-#ifdef DEBUG
-
-#define DLOG(a) a
-
-#undef stderr
-#define stderr STDERR
-FILE* stderr = NULL;
-
-static void checkpoint(void);
-
-#ifdef __MINGW32__
-void nonono(const char* file, int line, const char* msg) {
-    fprintf(stderr, "Nonono! %s:%d %s\n", file, line, msg);
-    exit(-5);
-}
-#undef assert
-#define assert(a) do {if (!(a)) nonono(__FILE__, __LINE__, #a);}while(0)
-#endif
-
-#else
-
-#define DLOG(a)
-
-#endif
-
-/* dynamic array functions */
-typedef struct array_t {
-    char* pointer;
-    unsigned int size,next,item_size;
-} array_t;
-
-static inline void array_init(array_t* array,unsigned int item_size)
-{
-    array->pointer = NULL;
-    array->size=0;
-    array->next=0;
-    array->item_size=item_size;
-}
-
-static inline void array_free(array_t* array)
-{
-    if(array->pointer)
-        free(array->pointer);
-    array->size=array->next=0;
-}
-
-/* does not automatically grow */
-static inline void* array_get(array_t* array,unsigned int index) {
-    assert(index < array->next);
-    return array->pointer + index * array->item_size;
-}
-
-static inline int array_ensure_allocated(array_t* array, int index)
-{
-    if((index + 1) * array->item_size > array->size) {
-	int new_size = (index + 32) * array->item_size;
-	array->pointer = qemu_realloc(array->pointer, new_size);
-	if (!array->pointer)
-	    return -1;
-	array->size = new_size;
-	array->next = index + 1;
-    }
-
-    return 0;
-}
-
-static inline void* array_get_next(array_t* array) {
-    unsigned int next = array->next;
-    void* result;
-
-    if (array_ensure_allocated(array, next) < 0)
-	return NULL;
-
-    array->next = next + 1;
-    result = array_get(array, next);
-
-    return result;
-}
-
-static inline void* array_insert(array_t* array,unsigned int index,unsigned int count) {
-    if((array->next+count)*array->item_size>array->size) {
-	int increment=count*array->item_size;
-	array->pointer=qemu_realloc(array->pointer,array->size+increment);
-	if(!array->pointer)
-            return NULL;
-	array->size+=increment;
-    }
-    memmove(array->pointer+(index+count)*array->item_size,
-		array->pointer+index*array->item_size,
-		(array->next-index)*array->item_size);
-    array->next+=count;
-    return array->pointer+index*array->item_size;
-}
-
-/* this performs a "roll", so that the element which was at index_from becomes
- * index_to, but the order of all other elements is preserved. */
-static inline int array_roll(array_t* array,int index_to,int index_from,int count)
-{
-    char* buf;
-    char* from;
-    char* to;
-    int is;
-
-    if(!array ||
-	    index_to<0 || index_to>=array->next ||
-	    index_from<0 || index_from>=array->next)
-	return -1;
-
-    if(index_to==index_from)
-	return 0;
-
-    is=array->item_size;
-    from=array->pointer+index_from*is;
-    to=array->pointer+index_to*is;
-    buf=qemu_malloc(is*count);
-    memcpy(buf,from,is*count);
-
-    if(index_to<index_from)
-	memmove(to+is*count,to,from-to);
-    else
-	memmove(from,from+is*count,to-from);
-
-    memcpy(to,buf,is*count);
-
-    free(buf);
-
-    return 0;
-}
-
-static inline int array_remove_slice(array_t* array,int index, int count)
-{
-    assert(index >=0);
-    assert(count > 0);
-    assert(index + count <= array->next);
-    if(array_roll(array,array->next-1,index,count))
-	return -1;
-    array->next -= count;
-    return 0;
-}
-
-static int array_remove(array_t* array,int index)
-{
-    return array_remove_slice(array, index, 1);
-}
-
-/* return the index for a given member */
-static int array_index(array_t* array, void* pointer)
-{
-    size_t offset = (char*)pointer - array->pointer;
-    assert((offset % array->item_size) == 0);
-    assert(offset/array->item_size < array->next);
-    return offset/array->item_size;
-}
-
-/* These structures are used to fake a disk and the VFAT filesystem.
- * For this reason we need to use __attribute__((packed)). */
-
-typedef struct bootsector_t {
-    uint8_t jump[3];
-    uint8_t name[8];
-    uint16_t sector_size;
-    uint8_t sectors_per_cluster;
-    uint16_t reserved_sectors;
-    uint8_t number_of_fats;
-    uint16_t root_entries;
-    uint16_t total_sectors16;
-    uint8_t media_type;
-    uint16_t sectors_per_fat;
-    uint16_t sectors_per_track;
-    uint16_t number_of_heads;
-    uint32_t hidden_sectors;
-    uint32_t total_sectors;
-    union {
-        struct {
-	    uint8_t drive_number;
-	    uint8_t current_head;
-	    uint8_t signature;
-	    uint32_t id;
-	    uint8_t volume_label[11];
-	} __attribute__((packed)) fat16;
-	struct {
-	    uint32_t sectors_per_fat;
-	    uint16_t flags;
-	    uint8_t major,minor;
-	    uint32_t first_cluster_of_root_directory;
-	    uint16_t info_sector;
-	    uint16_t backup_boot_sector;
-	    uint16_t ignored;
-	} __attribute__((packed)) fat32;
-    } u;
-    uint8_t fat_type[8];
-    uint8_t ignored[0x1c0];
-    uint8_t magic[2];
-} __attribute__((packed)) bootsector_t;
-
-typedef struct {
-    uint8_t head;
-    uint8_t sector;
-    uint8_t cylinder;
-} mbr_chs_t;
-
-typedef struct partition_t {
-    uint8_t attributes; /* 0x80 = bootable */
-    mbr_chs_t start_CHS;
-    uint8_t   fs_type; /* 0x1 = FAT12, 0x6 = FAT16, 0xe = FAT16_LBA, 0xb = FAT32, 0xc = FAT32_LBA */
-    mbr_chs_t end_CHS;
-    uint32_t start_sector_long;
-    uint32_t length_sector_long;
-} __attribute__((packed)) partition_t;
-
-typedef struct mbr_t {
-    uint8_t ignored[0x1b8];
-    uint32_t nt_id;
-    uint8_t ignored2[2];
-    partition_t partition[4];
-    uint8_t magic[2];
-} __attribute__((packed)) mbr_t;
-
-typedef struct direntry_t {
-    uint8_t name[8];
-    uint8_t extension[3];
-    uint8_t attributes;
-    uint8_t reserved[2];
-    uint16_t ctime;
-    uint16_t cdate;
-    uint16_t adate;
-    uint16_t begin_hi;
-    uint16_t mtime;
-    uint16_t mdate;
-    uint16_t begin;
-    uint32_t size;
-} __attribute__((packed)) direntry_t;
-
-/* this structure are used to transparently access the files */
-
-typedef struct mapping_t {
-    /* begin is the first cluster, end is the last+1 */
-    uint32_t begin,end;
-    /* as s->directory is growable, no pointer may be used here */
-    unsigned int dir_index;
-    /* the clusters of a file may be in any order; this points to the first */
-    int first_mapping_index;
-    union {
-	/* offset is
-	 * - the offset in the file (in clusters) for a file, or
-	 * - the next cluster of the directory for a directory, and
-	 * - the address of the buffer for a faked entry
-	 */
-	struct {
-	    uint32_t offset;
-	} file;
-	struct {
-	    int parent_mapping_index;
-	    int first_dir_index;
-	} dir;
-    } info;
-    /* path contains the full path, i.e. it always starts with s->path */
-    char* path;
-
-    enum { MODE_UNDEFINED = 0, MODE_NORMAL = 1, MODE_MODIFIED = 2,
-	MODE_DIRECTORY = 4, MODE_FAKED = 8,
-	MODE_DELETED = 16, MODE_RENAMED = 32 } mode;
-    int read_only;
-} mapping_t;
-
-#ifdef DEBUG
-static void print_direntry(const struct direntry_t*);
-static void print_mapping(const struct mapping_t* mapping);
-#endif
-
-/* here begins the real VVFAT driver */
-
-typedef struct BDRVVVFATState {
-    BlockDriverState* bs; /* pointer to parent */
-    unsigned int first_sectors_number; /* 1 for a single partition, 0x40 for a disk with partition table */
-    unsigned char first_sectors[0x40*0x200];
-
-    int fat_type; /* 16 or 32 */
-    array_t fat,directory,mapping;
-
-    unsigned int cluster_size;
-    unsigned int sectors_per_cluster;
-    unsigned int sectors_per_fat;
-    unsigned int sectors_of_root_directory;
-    uint32_t last_cluster_of_root_directory;
-    unsigned int faked_sectors; /* how many sectors are faked before file data */
-    uint32_t sector_count; /* total number of sectors of the partition */
-    uint32_t cluster_count; /* total number of clusters of this partition */
-    uint32_t max_fat_value;
-
-    int current_fd;
-    mapping_t* current_mapping;
-    unsigned char* cluster; /* points to current cluster */
-    unsigned char* cluster_buffer; /* points to a buffer to hold temp data */
-    unsigned int current_cluster;
-
-    /* write support */
-    BlockDriverState* write_target;
-    char* qcow_filename;
-    BlockDriverState* qcow;
-    void* fat2;
-    char* used_clusters;
-    array_t commits;
-    const char* path;
-    int downcase_short_names;
-} BDRVVVFATState;
-
-/* take the sector position spos and convert it to Cylinder/Head/Sector position
- * if the position is outside the specified geometry, fill maximum value for CHS
- * and return 1 to signal overflow.
- */
-static int sector2CHS(BlockDriverState* bs, mbr_chs_t * chs, int spos){
-    int head,sector;
-    sector   = spos % (bs->secs);  spos/= bs->secs;
-    head     = spos % (bs->heads); spos/= bs->heads;
-    if(spos >= bs->cyls){
-        /* Overflow,
-        it happens if 32bit sector positions are used, while CHS is only 24bit.
-        Windows/Dos is said to take 1023/255/63 as nonrepresentable CHS */
-        chs->head     = 0xFF;
-        chs->sector   = 0xFF;
-        chs->cylinder = 0xFF;
-        return 1;
-    }
-    chs->head     = (uint8_t)head;
-    chs->sector   = (uint8_t)( (sector+1) | ((spos>>8)<<6) );
-    chs->cylinder = (uint8_t)spos;
-    return 0;
-}
-
-static void init_mbr(BDRVVVFATState* s)
-{
-    /* TODO: if the files mbr.img and bootsect.img exist, use them */
-    mbr_t* real_mbr=(mbr_t*)s->first_sectors;
-    partition_t* partition=&(real_mbr->partition[0]);
-    int lba;
-
-    memset(s->first_sectors,0,512);
-
-    /* Win NT Disk Signature */
-    real_mbr->nt_id= cpu_to_le32(0xbe1afdfa);
-
-    partition->attributes=0x80; /* bootable */
-
-    /* LBA is used when partition is outside the CHS geometry */
-    lba = sector2CHS(s->bs, &partition->start_CHS, s->first_sectors_number-1);
-    lba|= sector2CHS(s->bs, &partition->end_CHS,   s->sector_count);
-
-    /*LBA partitions are identified only by start/length_sector_long not by CHS*/
-    partition->start_sector_long =cpu_to_le32(s->first_sectors_number-1);
-    partition->length_sector_long=cpu_to_le32(s->sector_count - s->first_sectors_number+1);
-
-    /* FAT12/FAT16/FAT32 */
-    /* DOS uses different types when partition is LBA,
-       probably to prevent older versions from using CHS on them */
-    partition->fs_type= s->fat_type==12 ? 0x1:
-                        s->fat_type==16 ? (lba?0xe:0x06):
-                         /*fat_tyoe==32*/ (lba?0xc:0x0b);
-
-    real_mbr->magic[0]=0x55; real_mbr->magic[1]=0xaa;
-}
-
-/* direntry functions */
-
-/* dest is assumed to hold 258 bytes, and pads with 0xffff up to next multiple of 26 */
-static inline int short2long_name(char* dest,const char* src)
-{
-    int i;
-    int len;
-    for(i=0;i<129 && src[i];i++) {
-        dest[2*i]=src[i];
-	dest[2*i+1]=0;
-    }
-    len=2*i;
-    dest[2*i]=dest[2*i+1]=0;
-    for(i=2*i+2;(i%26);i++)
-	dest[i]=0xff;
-    return len;
-}
-
-static inline direntry_t* create_long_filename(BDRVVVFATState* s,const char* filename)
-{
-    char buffer[258];
-    int length=short2long_name(buffer,filename),
-        number_of_entries=(length+25)/26,i;
-    direntry_t* entry;
-
-    for(i=0;i<number_of_entries;i++) {
-	entry=array_get_next(&(s->directory));
-	entry->attributes=0xf;
-	entry->reserved[0]=0;
-	entry->begin=0;
-	entry->name[0]=(number_of_entries-i)|(i==0?0x40:0);
-    }
-    for(i=0;i<26*number_of_entries;i++) {
-	int offset=(i%26);
-	if(offset<10) offset=1+offset;
-	else if(offset<22) offset=14+offset-10;
-	else offset=28+offset-22;
-	entry=array_get(&(s->directory),s->directory.next-1-(i/26));
-	entry->name[offset]=buffer[i];
-    }
-    return array_get(&(s->directory),s->directory.next-number_of_entries);
-}
-
-static char is_free(const direntry_t* direntry)
-{
-    return direntry->name[0]==0xe5 || direntry->name[0]==0x00;
-}
-
-static char is_volume_label(const direntry_t* direntry)
-{
-    return direntry->attributes == 0x28;
-}
-
-static char is_long_name(const direntry_t* direntry)
-{
-    return direntry->attributes == 0xf;
-}
-
-static char is_short_name(const direntry_t* direntry)
-{
-    return !is_volume_label(direntry) && !is_long_name(direntry)
-	&& !is_free(direntry);
-}
-
-static char is_directory(const direntry_t* direntry)
-{
-    return direntry->attributes & 0x10 && direntry->name[0] != 0xe5;
-}
-
-static inline char is_dot(const direntry_t* direntry)
-{
-    return is_short_name(direntry) && direntry->name[0] == '.';
-}
-
-static char is_file(const direntry_t* direntry)
-{
-    return is_short_name(direntry) && !is_directory(direntry);
-}
-
-static inline uint32_t begin_of_direntry(const direntry_t* direntry)
-{
-    return le16_to_cpu(direntry->begin)|(le16_to_cpu(direntry->begin_hi)<<16);
-}
-
-static inline uint32_t filesize_of_direntry(const direntry_t* direntry)
-{
-    return le32_to_cpu(direntry->size);
-}
-
-static void set_begin_of_direntry(direntry_t* direntry, uint32_t begin)
-{
-    direntry->begin = cpu_to_le16(begin & 0xffff);
-    direntry->begin_hi = cpu_to_le16((begin >> 16) & 0xffff);
-}
-
-/* fat functions */
-
-static inline uint8_t fat_chksum(const direntry_t* entry)
-{
-    uint8_t chksum=0;
-    int i;
-
-    for(i=0;i<11;i++) {
-        unsigned char c;
-
-        c = (i <= 8) ? entry->name[i] : entry->extension[i-8];
-        chksum=(((chksum&0xfe)>>1)|((chksum&0x01)?0x80:0)) + c;
-    }
-
-    return chksum;
-}
-
-/* if return_time==0, this returns the fat_date, else the fat_time */
-static uint16_t fat_datetime(time_t time,int return_time) {
-    struct tm* t;
-#ifdef _WIN32
-    t=localtime(&time); /* this is not thread safe */
-#else
-    struct tm t1;
-    t=&t1;
-    localtime_r(&time,t);
-#endif
-    if(return_time)
-	return cpu_to_le16((t->tm_sec/2)|(t->tm_min<<5)|(t->tm_hour<<11));
-    return cpu_to_le16((t->tm_mday)|((t->tm_mon+1)<<5)|((t->tm_year-80)<<9));
-}
-
-static inline void fat_set(BDRVVVFATState* s,unsigned int cluster,uint32_t value)
-{
-    if(s->fat_type==32) {
-	uint32_t* entry=array_get(&(s->fat),cluster);
-	*entry=cpu_to_le32(value);
-    } else if(s->fat_type==16) {
-	uint16_t* entry=array_get(&(s->fat),cluster);
-	*entry=cpu_to_le16(value&0xffff);
-    } else {
-	int offset = (cluster*3/2);
-	unsigned char* p = array_get(&(s->fat), offset);
-        switch (cluster&1) {
-	case 0:
-		p[0] = value&0xff;
-		p[1] = (p[1]&0xf0) | ((value>>8)&0xf);
-		break;
-	case 1:
-		p[0] = (p[0]&0xf) | ((value&0xf)<<4);
-		p[1] = (value>>4);
-		break;
-	}
-    }
-}
-
-static inline uint32_t fat_get(BDRVVVFATState* s,unsigned int cluster)
-{
-    if(s->fat_type==32) {
-	uint32_t* entry=array_get(&(s->fat),cluster);
-	return le32_to_cpu(*entry);
-    } else if(s->fat_type==16) {
-	uint16_t* entry=array_get(&(s->fat),cluster);
-	return le16_to_cpu(*entry);
-    } else {
-	const uint8_t* x=(uint8_t*)(s->fat.pointer)+cluster*3/2;
-	return ((x[0]|(x[1]<<8))>>(cluster&1?4:0))&0x0fff;
-    }
-}
-
-static inline int fat_eof(BDRVVVFATState* s,uint32_t fat_entry)
-{
-    if(fat_entry>s->max_fat_value-8)
-	return -1;
-    return 0;
-}
-
-static inline void init_fat(BDRVVVFATState* s)
-{
-    if (s->fat_type == 12) {
-	array_init(&(s->fat),1);
-	array_ensure_allocated(&(s->fat),
-		s->sectors_per_fat * 0x200 * 3 / 2 - 1);
-    } else {
-	array_init(&(s->fat),(s->fat_type==32?4:2));
-	array_ensure_allocated(&(s->fat),
-		s->sectors_per_fat * 0x200 / s->fat.item_size - 1);
-    }
-    memset(s->fat.pointer,0,s->fat.size);
-
-    switch(s->fat_type) {
-	case 12: s->max_fat_value=0xfff; break;
-	case 16: s->max_fat_value=0xffff; break;
-	case 32: s->max_fat_value=0x0fffffff; break;
-	default: s->max_fat_value=0; /* error... */
-    }
-
-}
-
-/* TODO: in create_short_filename, 0xe5->0x05 is not yet handled! */
-/* TODO: in parse_short_filename, 0x05->0xe5 is not yet handled! */
-static inline direntry_t* create_short_and_long_name(BDRVVVFATState* s,
-	unsigned int directory_start, const char* filename, int is_dot)
-{
-    int i,j,long_index=s->directory.next;
-    direntry_t* entry = NULL;
-    direntry_t* entry_long = NULL;
-
-    if(is_dot) {
-	entry=array_get_next(&(s->directory));
-	memset(entry->name,0x20,11);
-	memcpy(entry->name,filename,strlen(filename));
-	return entry;
-    }
-
-    entry_long=create_long_filename(s,filename);
-
-    i = strlen(filename);
-    for(j = i - 1; j>0  && filename[j]!='.';j--);
-    if (j > 0)
-	i = (j > 8 ? 8 : j);
-    else if (i > 8)
-	i = 8;
-
-    entry=array_get_next(&(s->directory));
-    memset(entry->name,0x20,11);
-    memcpy(entry->name, filename, i);
-
-    if(j > 0)
-	for (i = 0; i < 3 && filename[j+1+i]; i++)
-	    entry->extension[i] = filename[j+1+i];
-
-    /* upcase & remove unwanted characters */
-    for(i=10;i>=0;i--) {
-	if(i==10 || i==7) for(;i>0 && entry->name[i]==' ';i--);
-	if(entry->name[i]<=' ' || entry->name[i]>0x7f
-		|| strchr(".*?<>|\":/\\[];,+='",entry->name[i]))
-	    entry->name[i]='_';
-        else if(entry->name[i]>='a' && entry->name[i]<='z')
-            entry->name[i]+='A'-'a';
-    }
-
-    /* mangle duplicates */
-    while(1) {
-	direntry_t* entry1=array_get(&(s->directory),directory_start);
-	int j;
-
-	for(;entry1<entry;entry1++)
-	    if(!is_long_name(entry1) && !memcmp(entry1->name,entry->name,11))
-		break; /* found dupe */
-	if(entry1==entry) /* no dupe found */
-	    break;
-
-	/* use all 8 characters of name */
-	if(entry->name[7]==' ') {
-	    int j;
-	    for(j=6;j>0 && entry->name[j]==' ';j--)
-		entry->name[j]='~';
-	}
-
-	/* increment number */
-	for(j=7;j>0 && entry->name[j]=='9';j--)
-	    entry->name[j]='0';
-	if(j>0) {
-	    if(entry->name[j]<'0' || entry->name[j]>'9')
-	        entry->name[j]='0';
-	    else
-	        entry->name[j]++;
-	}
-    }
-
-    /* calculate checksum; propagate to long name */
-    if(entry_long) {
-        uint8_t chksum=fat_chksum(entry);
-
-	/* calculate anew, because realloc could have taken place */
-	entry_long=array_get(&(s->directory),long_index);
-	while(entry_long<entry && is_long_name(entry_long)) {
-	    entry_long->reserved[1]=chksum;
-	    entry_long++;
-	}
-    }
-
-    return entry;
-}
-
-/*
- * Read a directory. (the index of the corresponding mapping must be passed).
- */
-static int read_directory(BDRVVVFATState* s, int mapping_index)
-{
-    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
-    direntry_t* direntry;
-    const char* dirname = mapping->path;
-    int first_cluster = mapping->begin;
-    int parent_index = mapping->info.dir.parent_mapping_index;
-    mapping_t* parent_mapping = (mapping_t*)
-        (parent_index >= 0 ? array_get(&(s->mapping), parent_index) : NULL);
-    int first_cluster_of_parent = parent_mapping ? parent_mapping->begin : -1;
-
-    DIR* dir=opendir(dirname);
-    struct dirent* entry;
-    int i;
-
-    assert(mapping->mode & MODE_DIRECTORY);
-
-    if(!dir) {
-	mapping->end = mapping->begin;
-	return -1;
-    }
-
-    i = mapping->info.dir.first_dir_index =
-	    first_cluster == 0 ? 0 : s->directory.next;
-
-    /* actually read the directory, and allocate the mappings */
-    while((entry=readdir(dir))) {
-	unsigned int length=strlen(dirname)+2+strlen(entry->d_name);
-        char* buffer;
-	direntry_t* direntry;
-        struct stat st;
-	int is_dot=!strcmp(entry->d_name,".");
-	int is_dotdot=!strcmp(entry->d_name,"..");
-
-	if(first_cluster == 0 && (is_dotdot || is_dot))
-	    continue;
-
-	buffer=(char*)qemu_malloc(length);
-	snprintf(buffer,length,"%s/%s",dirname,entry->d_name);
-
-	if(stat(buffer,&st)<0) {
-	    free(buffer);
-            continue;
-	}
-
-	/* create directory entry for this file */
-	direntry=create_short_and_long_name(s, i, entry->d_name,
-		is_dot || is_dotdot);
-	direntry->attributes=(S_ISDIR(st.st_mode)?0x10:0x20);
-	direntry->reserved[0]=direntry->reserved[1]=0;
-	direntry->ctime=fat_datetime(st.st_ctime,1);
-	direntry->cdate=fat_datetime(st.st_ctime,0);
-	direntry->adate=fat_datetime(st.st_atime,0);
-	direntry->begin_hi=0;
-	direntry->mtime=fat_datetime(st.st_mtime,1);
-	direntry->mdate=fat_datetime(st.st_mtime,0);
-	if(is_dotdot)
-	    set_begin_of_direntry(direntry, first_cluster_of_parent);
-	else if(is_dot)
-	    set_begin_of_direntry(direntry, first_cluster);
-	else
-	    direntry->begin=0; /* do that later */
-        if (st.st_size > 0x7fffffff) {
-	    fprintf(stderr, "File %s is larger than 2GB\n", buffer);
-	    free(buffer);
-	    return -2;
-        }
-	direntry->size=cpu_to_le32(S_ISDIR(st.st_mode)?0:st.st_size);
-
-	/* create mapping for this file */
-	if(!is_dot && !is_dotdot && (S_ISDIR(st.st_mode) || st.st_size)) {
-	    s->current_mapping=(mapping_t*)array_get_next(&(s->mapping));
-	    s->current_mapping->begin=0;
-	    s->current_mapping->end=st.st_size;
-	    /*
-	     * we get the direntry of the most recent direntry, which
-	     * contains the short name and all the relevant information.
-	     */
-	    s->current_mapping->dir_index=s->directory.next-1;
-	    s->current_mapping->first_mapping_index = -1;
-	    if (S_ISDIR(st.st_mode)) {
-		s->current_mapping->mode = MODE_DIRECTORY;
-		s->current_mapping->info.dir.parent_mapping_index =
-		    mapping_index;
-	    } else {
-		s->current_mapping->mode = MODE_UNDEFINED;
-		s->current_mapping->info.file.offset = 0;
-	    }
-	    s->current_mapping->path=buffer;
-	    s->current_mapping->read_only =
-		(st.st_mode & (S_IWUSR | S_IWGRP | S_IWOTH)) == 0;
-	}
-    }
-    closedir(dir);
-
-    /* fill with zeroes up to the end of the cluster */
-    while(s->directory.next%(0x10*s->sectors_per_cluster)) {
-	direntry_t* direntry=array_get_next(&(s->directory));
-	memset(direntry,0,sizeof(direntry_t));
-    }
-
-/* TODO: if there are more entries, bootsector has to be adjusted! */
-#define ROOT_ENTRIES (0x02 * 0x10 * s->sectors_per_cluster)
-    if (mapping_index == 0 && s->directory.next < ROOT_ENTRIES) {
-	/* root directory */
-	int cur = s->directory.next;
-	array_ensure_allocated(&(s->directory), ROOT_ENTRIES - 1);
-	memset(array_get(&(s->directory), cur), 0,
-		(ROOT_ENTRIES - cur) * sizeof(direntry_t));
-    }
-
-     /* reget the mapping, since s->mapping was possibly realloc()ed */
-    mapping = (mapping_t*)array_get(&(s->mapping), mapping_index);
-    first_cluster += (s->directory.next - mapping->info.dir.first_dir_index)
-	* 0x20 / s->cluster_size;
-    mapping->end = first_cluster;
-
-    direntry = (direntry_t*)array_get(&(s->directory), mapping->dir_index);
-    set_begin_of_direntry(direntry, mapping->begin);
-
-    return 0;
-}
-
-static inline uint32_t sector2cluster(BDRVVVFATState* s,off_t sector_num)
-{
-    return (sector_num-s->faked_sectors)/s->sectors_per_cluster;
-}
-
-static inline off_t cluster2sector(BDRVVVFATState* s, uint32_t cluster_num)
-{
-    return s->faked_sectors + s->sectors_per_cluster * cluster_num;
-}
-
-static inline uint32_t sector_offset_in_cluster(BDRVVVFATState* s,off_t sector_num)
-{
-    return (sector_num-s->first_sectors_number-2*s->sectors_per_fat)%s->sectors_per_cluster;
-}
-
-#ifdef DBG
-static direntry_t* get_direntry_for_mapping(BDRVVVFATState* s,mapping_t* mapping)
-{
-    if(mapping->mode==MODE_UNDEFINED)
-	return 0;
-    return (direntry_t*)(s->directory.pointer+sizeof(direntry_t)*mapping->dir_index);
-}
-#endif
-
-static int init_directories(BDRVVVFATState* s,
-	const char* dirname)
-{
-    bootsector_t* bootsector;
-    mapping_t* mapping;
-    unsigned int i;
-    unsigned int cluster;
-
-    memset(&(s->first_sectors[0]),0,0x40*0x200);
-
-    s->cluster_size=s->sectors_per_cluster*0x200;
-    s->cluster_buffer=qemu_malloc(s->cluster_size);
-
-    /*
-     * The formula: sc = spf+1+spf*spc*(512*8/fat_type),
-     * where sc is sector_count,
-     * spf is sectors_per_fat,
-     * spc is sectors_per_clusters, and
-     * fat_type = 12, 16 or 32.
-     */
-    i = 1+s->sectors_per_cluster*0x200*8/s->fat_type;
-    s->sectors_per_fat=(s->sector_count+i)/i; /* round up */
-
-    array_init(&(s->mapping),sizeof(mapping_t));
-    array_init(&(s->directory),sizeof(direntry_t));
-
-    /* add volume label */
-    {
-	direntry_t* entry=array_get_next(&(s->directory));
-	entry->attributes=0x28; /* archive | volume label */
-	snprintf((char*)entry->name,11,"QEMU VVFAT");
-    }
-
-    /* Now build FAT, and write back information into directory */
-    init_fat(s);
-
-    s->faked_sectors=s->first_sectors_number+s->sectors_per_fat*2;
-    s->cluster_count=sector2cluster(s, s->sector_count);
-
-    mapping = array_get_next(&(s->mapping));
-    mapping->begin = 0;
-    mapping->dir_index = 0;
-    mapping->info.dir.parent_mapping_index = -1;
-    mapping->first_mapping_index = -1;
-    mapping->path = strdup(dirname);
-    i = strlen(mapping->path);
-    if (i > 0 && mapping->path[i - 1] == '/')
-	mapping->path[i - 1] = '\0';
-    mapping->mode = MODE_DIRECTORY;
-    mapping->read_only = 0;
-    s->path = mapping->path;
-
-    for (i = 0, cluster = 0; i < s->mapping.next; i++) {
-	/* MS-DOS expects the FAT to be 0 for the root directory
-	 * (except for the media byte). */
-	/* LATER TODO: still true for FAT32? */
-	int fix_fat = (i != 0);
-	mapping = array_get(&(s->mapping), i);
-
-        if (mapping->mode & MODE_DIRECTORY) {
-	    mapping->begin = cluster;
-	    if(read_directory(s, i)) {
-		fprintf(stderr, "Could not read directory %s\n",
-			mapping->path);
-		return -1;
-	    }
-	    mapping = array_get(&(s->mapping), i);
-	} else {
-	    assert(mapping->mode == MODE_UNDEFINED);
-	    mapping->mode=MODE_NORMAL;
-	    mapping->begin = cluster;
-	    if (mapping->end > 0) {
-		direntry_t* direntry = array_get(&(s->directory),
-			mapping->dir_index);
-
-		mapping->end = cluster + 1 + (mapping->end-1)/s->cluster_size;
-		set_begin_of_direntry(direntry, mapping->begin);
-	    } else {
-		mapping->end = cluster + 1;
-		fix_fat = 0;
-	    }
-	}
-
-	assert(mapping->begin < mapping->end);
-
-	/* next free cluster */
-	cluster = mapping->end;
-
-	if(cluster > s->cluster_count) {
-	    fprintf(stderr,"Directory does not fit in FAT%d (capacity %s)\n",
-		    s->fat_type,
-		    s->fat_type == 12 ? s->sector_count == 2880 ? "1.44 MB"
-								: "2.88 MB"
-				      : "504MB");
-	    return -EINVAL;
-	}
-
-	/* fix fat for entry */
-	if (fix_fat) {
-	    int j;
-	    for(j = mapping->begin; j < mapping->end - 1; j++)
-		fat_set(s, j, j+1);
-	    fat_set(s, mapping->end - 1, s->max_fat_value);
-	}
-    }
-
-    mapping = array_get(&(s->mapping), 0);
-    s->sectors_of_root_directory = mapping->end * s->sectors_per_cluster;
-    s->last_cluster_of_root_directory = mapping->end;
-
-    /* the FAT signature */
-    fat_set(s,0,s->max_fat_value);
-    fat_set(s,1,s->max_fat_value);
-
-    s->current_mapping = NULL;
-
-    bootsector=(bootsector_t*)(s->first_sectors+(s->first_sectors_number-1)*0x200);
-    bootsector->jump[0]=0xeb;
-    bootsector->jump[1]=0x3e;
-    bootsector->jump[2]=0x90;
-    memcpy(bootsector->name,"QEMU    ",8);
-    bootsector->sector_size=cpu_to_le16(0x200);
-    bootsector->sectors_per_cluster=s->sectors_per_cluster;
-    bootsector->reserved_sectors=cpu_to_le16(1);
-    bootsector->number_of_fats=0x2; /* number of FATs */
-    bootsector->root_entries=cpu_to_le16(s->sectors_of_root_directory*0x10);
-    bootsector->total_sectors16=s->sector_count>0xffff?0:cpu_to_le16(s->sector_count);
-    bootsector->media_type=(s->fat_type!=12?0xf8:s->sector_count==5760?0xf9:0xf8); /* media descriptor */
-    s->fat.pointer[0] = bootsector->media_type;
-    bootsector->sectors_per_fat=cpu_to_le16(s->sectors_per_fat);
-    bootsector->sectors_per_track=cpu_to_le16(s->bs->secs);
-    bootsector->number_of_heads=cpu_to_le16(s->bs->heads);
-    bootsector->hidden_sectors=cpu_to_le32(s->first_sectors_number==1?0:0x3f);
-    bootsector->total_sectors=cpu_to_le32(s->sector_count>0xffff?s->sector_count:0);
-
-    /* LATER TODO: if FAT32, this is wrong */
-    bootsector->u.fat16.drive_number=s->fat_type==12?0:0x80; /* assume this is hda (TODO) */
-    bootsector->u.fat16.current_head=0;
-    bootsector->u.fat16.signature=0x29;
-    bootsector->u.fat16.id=cpu_to_le32(0xfabe1afd);
-
-    memcpy(bootsector->u.fat16.volume_label,"QEMU VVFAT ",11);
-    memcpy(bootsector->fat_type,(s->fat_type==12?"FAT12   ":s->fat_type==16?"FAT16   ":"FAT32   "),8);
-    bootsector->magic[0]=0x55; bootsector->magic[1]=0xaa;
-
-    return 0;
-}
-
-#ifdef DEBUG
-static BDRVVVFATState *vvv = NULL;
-#endif
-
-static int enable_write_target(BDRVVVFATState *s);
-static int is_consistent(BDRVVVFATState *s);
-
-static int vvfat_open(BlockDriverState *bs, const char* dirname, int flags)
-{
-    BDRVVVFATState *s = bs->opaque;
-    int floppy = 0;
-    int i;
-
-#ifdef DEBUG
-    vvv = s;
-#endif
-
-DLOG(if (stderr == NULL) {
-    stderr = fopen("vvfat.log", "a");
-    setbuf(stderr, NULL);
-})
-
-    s->bs = bs;
-
-    s->fat_type=16;
-    /* LATER TODO: if FAT32, adjust */
-    s->sectors_per_cluster=0x10;
-    /* 504MB disk*/
-    bs->cyls=1024; bs->heads=16; bs->secs=63;
-
-    s->current_cluster=0xffffffff;
-
-    s->first_sectors_number=0x40;
-    /* read only is the default for safety */
-    bs->read_only = 1;
-    s->qcow = s->write_target = NULL;
-    s->qcow_filename = NULL;
-    s->fat2 = NULL;
-    s->downcase_short_names = 1;
-
-    if (!strstart(dirname, "fat:", NULL))
-	return -1;
-
-    if (strstr(dirname, ":floppy:")) {
-	floppy = 1;
-	s->fat_type = 12;
-	s->first_sectors_number = 1;
-	s->sectors_per_cluster=2;
-	bs->cyls = 80; bs->heads = 2; bs->secs = 36;
-    }
-
-    s->sector_count=bs->cyls*bs->heads*bs->secs;
-
-    if (strstr(dirname, ":32:")) {
-	fprintf(stderr, "Big fat greek warning: FAT32 has not been tested. You are welcome to do so!\n");
-	s->fat_type = 32;
-    } else if (strstr(dirname, ":16:")) {
-	s->fat_type = 16;
-    } else if (strstr(dirname, ":12:")) {
-	s->fat_type = 12;
-	s->sector_count=2880;
-    }
-
-    if (strstr(dirname, ":rw:")) {
-	if (enable_write_target(s))
-	    return -1;
-	bs->read_only = 0;
-    }
-
-    i = strrchr(dirname, ':') - dirname;
-    assert(i >= 3);
-    if (dirname[i-2] == ':' && qemu_isalpha(dirname[i-1]))
-	/* workaround for DOS drive names */
-	dirname += i-1;
-    else
-	dirname += i+1;
-
-    bs->total_sectors=bs->cyls*bs->heads*bs->secs;
-
-    if(init_directories(s, dirname))
-	return -1;
-
-    s->sector_count = s->faked_sectors + s->sectors_per_cluster*s->cluster_count;
-
-    if(s->first_sectors_number==0x40)
-	init_mbr(s);
-
-    /* for some reason or other, MS-DOS does not like to know about CHS... */
-    if (floppy)
-	bs->heads = bs->cyls = bs->secs = 0;
-
-    //    assert(is_consistent(s));
-    return 0;
-}
-
-static inline void vvfat_close_current_file(BDRVVVFATState *s)
-{
-    if(s->current_mapping) {
-	s->current_mapping = NULL;
-	if (s->current_fd) {
-		close(s->current_fd);
-		s->current_fd = 0;
-	}
-    }
-    s->current_cluster = -1;
-}
-
-/* mappings between index1 and index2-1 are supposed to be ordered
- * return value is the index of the last mapping for which end>cluster_num
- */
-static inline int find_mapping_for_cluster_aux(BDRVVVFATState* s,int cluster_num,int index1,int index2)
-{
-    int index3=index1+1;
-    while(1) {
-	mapping_t* mapping;
-	index3=(index1+index2)/2;
-	mapping=array_get(&(s->mapping),index3);
-	assert(mapping->begin < mapping->end);
-	if(mapping->begin>=cluster_num) {
-	    assert(index2!=index3 || index2==0);
-	    if(index2==index3)
-		return index1;
-	    index2=index3;
-	} else {
-	    if(index1==index3)
-		return mapping->end<=cluster_num ? index2 : index1;
-	    index1=index3;
-	}
-	assert(index1<=index2);
-	DLOG(mapping=array_get(&(s->mapping),index1);
-	assert(mapping->begin<=cluster_num);
-	assert(index2 >= s->mapping.next ||
-		((mapping = array_get(&(s->mapping),index2)) &&
-		mapping->end>cluster_num)));
-    }
-}
-
-static inline mapping_t* find_mapping_for_cluster(BDRVVVFATState* s,int cluster_num)
-{
-    int index=find_mapping_for_cluster_aux(s,cluster_num,0,s->mapping.next);
-    mapping_t* mapping;
-    if(index>=s->mapping.next)
-        return NULL;
-    mapping=array_get(&(s->mapping),index);
-    if(mapping->begin>cluster_num)
-        return NULL;
-    assert(mapping->begin<=cluster_num && mapping->end>cluster_num);
-    return mapping;
-}
-
-/*
- * This function simply compares path == mapping->path. Since the mappings
- * are sorted by cluster, this is expensive: O(n).
- */
-static inline mapping_t* find_mapping_for_path(BDRVVVFATState* s,
-	const char* path)
-{
-    int i;
-
-    for (i = 0; i < s->mapping.next; i++) {
-	mapping_t* mapping = array_get(&(s->mapping), i);
-	if (mapping->first_mapping_index < 0 &&
-		!strcmp(path, mapping->path))
-	    return mapping;
-    }
-
-    return NULL;
-}
-
-static int open_file(BDRVVVFATState* s,mapping_t* mapping)
-{
-    if(!mapping)
-	return -1;
-    if(!s->current_mapping ||
-	    strcmp(s->current_mapping->path,mapping->path)) {
-	/* open file */
-	int fd = open(mapping->path, O_RDONLY | O_BINARY | O_LARGEFILE);
-	if(fd<0)
-	    return -1;
-	vvfat_close_current_file(s);
-	s->current_fd = fd;
-	s->current_mapping = mapping;
-    }
-    return 0;
-}
-
-static inline int read_cluster(BDRVVVFATState *s,int cluster_num)
-{
-    if(s->current_cluster != cluster_num) {
-	int result=0;
-	off_t offset;
-	assert(!s->current_mapping || s->current_fd || (s->current_mapping->mode & MODE_DIRECTORY));
-	if(!s->current_mapping
-		|| s->current_mapping->begin>cluster_num
-		|| s->current_mapping->end<=cluster_num) {
-	    /* binary search of mappings for file */
-	    mapping_t* mapping=find_mapping_for_cluster(s,cluster_num);
-
-	    assert(!mapping || (cluster_num>=mapping->begin && cluster_num<mapping->end));
-
-	    if (mapping && mapping->mode & MODE_DIRECTORY) {
-		vvfat_close_current_file(s);
-		s->current_mapping = mapping;
-read_cluster_directory:
-		offset = s->cluster_size*(cluster_num-s->current_mapping->begin);
-		s->cluster = (unsigned char*)s->directory.pointer+offset
-			+ 0x20*s->current_mapping->info.dir.first_dir_index;
-		assert(((s->cluster-(unsigned char*)s->directory.pointer)%s->cluster_size)==0);
-		assert((char*)s->cluster+s->cluster_size <= s->directory.pointer+s->directory.next*s->directory.item_size);
-		s->current_cluster = cluster_num;
-		return 0;
-	    }
-
-	    if(open_file(s,mapping))
-		return -2;
-	} else if (s->current_mapping->mode & MODE_DIRECTORY)
-	    goto read_cluster_directory;
-
-	assert(s->current_fd);
-
-	offset=s->cluster_size*(cluster_num-s->current_mapping->begin)+s->current_mapping->info.file.offset;
-	if(lseek(s->current_fd, offset, SEEK_SET)!=offset)
-	    return -3;
-	s->cluster=s->cluster_buffer;
-	result=read(s->current_fd,s->cluster,s->cluster_size);
-	if(result<0) {
-	    s->current_cluster = -1;
-	    return -1;
-	}
-	s->current_cluster = cluster_num;
-    }
-    return 0;
-}
-
-#ifdef DEBUG
-static void hexdump(const void* address, uint32_t len)
-{
-    const unsigned char* p = address;
-    int i, j;
-
-    for (i = 0; i < len; i += 16) {
-	for (j = 0; j < 16 && i + j < len; j++)
-	    fprintf(stderr, "%02x ", p[i + j]);
-	for (; j < 16; j++)
-	    fprintf(stderr, "   ");
-	fprintf(stderr, " ");
-	for (j = 0; j < 16 && i + j < len; j++)
-	    fprintf(stderr, "%c", (p[i + j] < ' ' || p[i + j] > 0x7f) ? '.' : p[i + j]);
-	fprintf(stderr, "\n");
-    }
-}
-
-static void print_direntry(const direntry_t* direntry)
-{
-    int j = 0;
-    char buffer[1024];
-
-    fprintf(stderr, "direntry 0x%x: ", (int)direntry);
-    if(!direntry)
-	return;
-    if(is_long_name(direntry)) {
-	unsigned char* c=(unsigned char*)direntry;
-	int i;
-	for(i=1;i<11 && c[i] && c[i]!=0xff;i+=2)
-#define ADD_CHAR(c) {buffer[j] = (c); if (buffer[j] < ' ') buffer[j] = 0xb0; j++;}
-	    ADD_CHAR(c[i]);
-	for(i=14;i<26 && c[i] && c[i]!=0xff;i+=2)
-	    ADD_CHAR(c[i]);
-	for(i=28;i<32 && c[i] && c[i]!=0xff;i+=2)
-	    ADD_CHAR(c[i]);
-	buffer[j] = 0;
-	fprintf(stderr, "%s\n", buffer);
-    } else {
-	int i;
-	for(i=0;i<11;i++)
-	    ADD_CHAR(direntry->name[i]);
-	buffer[j] = 0;
-	fprintf(stderr,"%s attributes=0x%02x begin=%d size=%d\n",
-		buffer,
-		direntry->attributes,
-		begin_of_direntry(direntry),le32_to_cpu(direntry->size));
-    }
-}
-
-static void print_mapping(const mapping_t* mapping)
-{
-    fprintf(stderr, "mapping (0x%x): begin, end = %d, %d, dir_index = %d, first_mapping_index = %d, name = %s, mode = 0x%x, " , (int)mapping, mapping->begin, mapping->end, mapping->dir_index, mapping->first_mapping_index, mapping->path, mapping->mode);
-    if (mapping->mode & MODE_DIRECTORY)
-	fprintf(stderr, "parent_mapping_index = %d, first_dir_index = %d\n", mapping->info.dir.parent_mapping_index, mapping->info.dir.first_dir_index);
-    else
-	fprintf(stderr, "offset = %d\n", mapping->info.file.offset);
-}
-#endif
-
-static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
-                    uint8_t *buf, int nb_sectors)
-{
-    BDRVVVFATState *s = bs->opaque;
-    int i;
-
-    for(i=0;i<nb_sectors;i++,sector_num++) {
-	if (sector_num >= s->sector_count)
-	   return -1;
-	if (s->qcow) {
-	    int n;
-	    if (s->qcow->drv->bdrv_is_allocated(s->qcow,
-			sector_num, nb_sectors-i, &n)) {
-DLOG(fprintf(stderr, "sectors %d+%d allocated\n", (int)sector_num, n));
-		if (s->qcow->drv->bdrv_read(s->qcow, sector_num, buf+i*0x200, n))
-		    return -1;
-		i += n - 1;
-		sector_num += n - 1;
-		continue;
-	    }
-DLOG(fprintf(stderr, "sector %d not allocated\n", (int)sector_num));
-	}
-	if(sector_num<s->faked_sectors) {
-	    if(sector_num<s->first_sectors_number)
-		memcpy(buf+i*0x200,&(s->first_sectors[sector_num*0x200]),0x200);
-	    else if(sector_num-s->first_sectors_number<s->sectors_per_fat)
-		memcpy(buf+i*0x200,&(s->fat.pointer[(sector_num-s->first_sectors_number)*0x200]),0x200);
-	    else if(sector_num-s->first_sectors_number-s->sectors_per_fat<s->sectors_per_fat)
-		memcpy(buf+i*0x200,&(s->fat.pointer[(sector_num-s->first_sectors_number-s->sectors_per_fat)*0x200]),0x200);
-	} else {
-	    uint32_t sector=sector_num-s->faked_sectors,
-	    sector_offset_in_cluster=(sector%s->sectors_per_cluster),
-	    cluster_num=sector/s->sectors_per_cluster;
-	    if(read_cluster(s, cluster_num) != 0) {
-		/* LATER TODO: strict: return -1; */
-		memset(buf+i*0x200,0,0x200);
-		continue;
-	    }
-	    memcpy(buf+i*0x200,s->cluster+sector_offset_in_cluster*0x200,0x200);
-	}
-    }
-    return 0;
-}
-
-/* LATER TODO: statify all functions */
-
-/*
- * Idea of the write support (use snapshot):
- *
- * 1. check if all data is consistent, recording renames, modifications,
- *    new files and directories (in s->commits).
- *
- * 2. if the data is not consistent, stop committing
- *
- * 3. handle renames, and create new files and directories (do not yet
- *    write their contents)
- *
- * 4. walk the directories, fixing the mapping and direntries, and marking
- *    the handled mappings as not deleted
- *
- * 5. commit the contents of the files
- *
- * 6. handle deleted files and directories
- *
- */
-
-typedef struct commit_t {
-    char* path;
-    union {
-	struct { uint32_t cluster; } rename;
-	struct { int dir_index; uint32_t modified_offset; } writeout;
-	struct { uint32_t first_cluster; } new_file;
-	struct { uint32_t cluster; } mkdir;
-    } param;
-    /* DELETEs and RMDIRs are handled differently: see handle_deletes() */
-    enum {
-	ACTION_RENAME, ACTION_WRITEOUT, ACTION_NEW_FILE, ACTION_MKDIR
-    } action;
-} commit_t;
-
-static void clear_commits(BDRVVVFATState* s)
-{
-    int i;
-DLOG(fprintf(stderr, "clear_commits (%d commits)\n", s->commits.next));
-    for (i = 0; i < s->commits.next; i++) {
-	commit_t* commit = array_get(&(s->commits), i);
-	assert(commit->path || commit->action == ACTION_WRITEOUT);
-	if (commit->action != ACTION_WRITEOUT) {
-	    assert(commit->path);
-	    free(commit->path);
-	} else
-	    assert(commit->path == NULL);
-    }
-    s->commits.next = 0;
-}
-
-static void schedule_rename(BDRVVVFATState* s,
-	uint32_t cluster, char* new_path)
-{
-    commit_t* commit = array_get_next(&(s->commits));
-    commit->path = new_path;
-    commit->param.rename.cluster = cluster;
-    commit->action = ACTION_RENAME;
-}
-
-static void schedule_writeout(BDRVVVFATState* s,
-	int dir_index, uint32_t modified_offset)
-{
-    commit_t* commit = array_get_next(&(s->commits));
-    commit->path = NULL;
-    commit->param.writeout.dir_index = dir_index;
-    commit->param.writeout.modified_offset = modified_offset;
-    commit->action = ACTION_WRITEOUT;
-}
-
-static void schedule_new_file(BDRVVVFATState* s,
-	char* path, uint32_t first_cluster)
-{
-    commit_t* commit = array_get_next(&(s->commits));
-    commit->path = path;
-    commit->param.new_file.first_cluster = first_cluster;
-    commit->action = ACTION_NEW_FILE;
-}
-
-static void schedule_mkdir(BDRVVVFATState* s, uint32_t cluster, char* path)
-{
-    commit_t* commit = array_get_next(&(s->commits));
-    commit->path = path;
-    commit->param.mkdir.cluster = cluster;
-    commit->action = ACTION_MKDIR;
-}
-
-typedef struct {
-    /*
-     * Since the sequence number is at most 0x3f, and the filename
-     * length is at most 13 times the sequence number, the maximal
-     * filename length is 0x3f * 13 bytes.
-     */
-    unsigned char name[0x3f * 13 + 1];
-    int checksum, len;
-    int sequence_number;
-} long_file_name;
-
-static void lfn_init(long_file_name* lfn)
-{
-   lfn->sequence_number = lfn->len = 0;
-   lfn->checksum = 0x100;
-}
-
-/* return 0 if parsed successfully, > 0 if no long name, < 0 if error */
-static int parse_long_name(long_file_name* lfn,
-	const direntry_t* direntry)
-{
-    int i, j, offset;
-    const unsigned char* pointer = (const unsigned char*)direntry;
-
-    if (!is_long_name(direntry))
-	return 1;
-
-    if (pointer[0] & 0x40) {
-	lfn->sequence_number = pointer[0] & 0x3f;
-	lfn->checksum = pointer[13];
-	lfn->name[0] = 0;
-	lfn->name[lfn->sequence_number * 13] = 0;
-    } else if ((pointer[0] & 0x3f) != --lfn->sequence_number)
-	return -1;
-    else if (pointer[13] != lfn->checksum)
-	return -2;
-    else if (pointer[12] || pointer[26] || pointer[27])
-	return -3;
-
-    offset = 13 * (lfn->sequence_number - 1);
-    for (i = 0, j = 1; i < 13; i++, j+=2) {
-	if (j == 11)
-	    j = 14;
-	else if (j == 26)
-	    j = 28;
-
-	if (pointer[j+1] == 0)
-	    lfn->name[offset + i] = pointer[j];
-	else if (pointer[j+1] != 0xff || (pointer[0] & 0x40) == 0)
-	    return -4;
-	else
-	    lfn->name[offset + i] = 0;
-    }
-
-    if (pointer[0] & 0x40)
-	lfn->len = offset + strlen((char*)lfn->name + offset);
-
-    return 0;
-}
-
-/* returns 0 if successful, >0 if no short_name, and <0 on error */
-static int parse_short_name(BDRVVVFATState* s,
-	long_file_name* lfn, direntry_t* direntry)
-{
-    int i, j;
-
-    if (!is_short_name(direntry))
-	return 1;
-
-    for (j = 7; j >= 0 && direntry->name[j] == ' '; j--);
-    for (i = 0; i <= j; i++) {
-	if (direntry->name[i] <= ' ' || direntry->name[i] > 0x7f)
-	    return -1;
-	else if (s->downcase_short_names)
-	    lfn->name[i] = qemu_tolower(direntry->name[i]);
-	else
-	    lfn->name[i] = direntry->name[i];
-    }
-
-    for (j = 2; j >= 0 && direntry->extension[j] == ' '; j--);
-    if (j >= 0) {
-	lfn->name[i++] = '.';
-	lfn->name[i + j + 1] = '\0';
-	for (;j >= 0; j--) {
-	    if (direntry->extension[j] <= ' ' || direntry->extension[j] > 0x7f)
-		return -2;
-	    else if (s->downcase_short_names)
-		lfn->name[i + j] = qemu_tolower(direntry->extension[j]);
-	    else
-		lfn->name[i + j] = direntry->extension[j];
-	}
-    } else
-	lfn->name[i + j + 1] = '\0';
-
-    lfn->len = strlen((char*)lfn->name);
-
-    return 0;
-}
-
-static inline uint32_t modified_fat_get(BDRVVVFATState* s,
-	unsigned int cluster)
-{
-    if (cluster < s->last_cluster_of_root_directory) {
-	if (cluster + 1 == s->last_cluster_of_root_directory)
-	    return s->max_fat_value;
-	else
-	    return cluster + 1;
-    }
-
-    if (s->fat_type==32) {
-        uint32_t* entry=((uint32_t*)s->fat2)+cluster;
-        return le32_to_cpu(*entry);
-    } else if (s->fat_type==16) {
-        uint16_t* entry=((uint16_t*)s->fat2)+cluster;
-        return le16_to_cpu(*entry);
-    } else {
-        const uint8_t* x=s->fat2+cluster*3/2;
-        return ((x[0]|(x[1]<<8))>>(cluster&1?4:0))&0x0fff;
-    }
-}
-
-static inline int cluster_was_modified(BDRVVVFATState* s, uint32_t cluster_num)
-{
-    int was_modified = 0;
-    int i, dummy;
-
-    if (s->qcow == NULL)
-	return 0;
-
-    for (i = 0; !was_modified && i < s->sectors_per_cluster; i++)
-	was_modified = s->qcow->drv->bdrv_is_allocated(s->qcow,
-		cluster2sector(s, cluster_num) + i, 1, &dummy);
-
-    return was_modified;
-}
-
-static const char* get_basename(const char* path)
-{
-    char* basename = strrchr(path, '/');
-    if (basename == NULL)
-	return path;
-    else
-	return basename + 1; /* strip '/' */
-}
-
-/*
- * The array s->used_clusters holds the states of the clusters. If it is
- * part of a file, it has bit 2 set, in case of a directory, bit 1. If it
- * was modified, bit 3 is set.
- * If any cluster is allocated, but not part of a file or directory, this
- * driver refuses to commit.
- */
-typedef enum {
-     USED_DIRECTORY = 1, USED_FILE = 2, USED_ANY = 3, USED_ALLOCATED = 4
-} used_t;
-
-/*
- * get_cluster_count_for_direntry() not only determines how many clusters
- * are occupied by direntry, but also if it was renamed or modified.
- *
- * A file is thought to be renamed *only* if there already was a file with
- * exactly the same first cluster, but a different name.
- *
- * Further, the files/directories handled by this function are
- * assumed to be *not* deleted (and *only* those).
- */
-static uint32_t get_cluster_count_for_direntry(BDRVVVFATState* s,
-	direntry_t* direntry, const char* path)
-{
-    /*
-     * This is a little bit tricky:
-     * IF the guest OS just inserts a cluster into the file chain,
-     * and leaves the rest alone, (i.e. the original file had clusters
-     * 15 -> 16, but now has 15 -> 32 -> 16), then the following happens:
-     *
-     * - do_commit will write the cluster into the file at the given
-     *   offset, but
-     *
-     * - the cluster which is overwritten should be moved to a later
-     *   position in the file.
-     *
-     * I am not aware that any OS does something as braindead, but this
-     * situation could happen anyway when not committing for a long time.
-     * Just to be sure that this does not bite us, detect it, and copy the
-     * contents of the clusters to-be-overwritten into the qcow.
-     */
-    int copy_it = 0;
-    int was_modified = 0;
-    int32_t ret = 0;
-
-    uint32_t cluster_num = begin_of_direntry(direntry);
-    uint32_t offset = 0;
-    int first_mapping_index = -1;
-    mapping_t* mapping = NULL;
-    const char* basename2 = NULL;
-
-    vvfat_close_current_file(s);
-
-    /* the root directory */
-    if (cluster_num == 0)
-	return 0;
-
-    /* write support */
-    if (s->qcow) {
-	basename2 = get_basename(path);
-
-	mapping = find_mapping_for_cluster(s, cluster_num);
-
-	if (mapping) {
-	    const char* basename;
-
-	    assert(mapping->mode & MODE_DELETED);
-	    mapping->mode &= ~MODE_DELETED;
-
-	    basename = get_basename(mapping->path);
-
-	    assert(mapping->mode & MODE_NORMAL);
-
-	    /* rename */
-	    if (strcmp(basename, basename2))
-		schedule_rename(s, cluster_num, strdup(path));
-	} else if (is_file(direntry))
-	    /* new file */
-	    schedule_new_file(s, strdup(path), cluster_num);
-	else {
-	    assert(0);
-	    return 0;
-	}
-    }
-
-    while(1) {
-	if (s->qcow) {
-	    if (!copy_it && cluster_was_modified(s, cluster_num)) {
-		if (mapping == NULL ||
-			mapping->begin > cluster_num ||
-			mapping->end <= cluster_num)
-		mapping = find_mapping_for_cluster(s, cluster_num);
-
-
-		if (mapping &&
-			(mapping->mode & MODE_DIRECTORY) == 0) {
-
-		    /* was modified in qcow */
-		    if (offset != mapping->info.file.offset + s->cluster_size
-			    * (cluster_num - mapping->begin)) {
-			/* offset of this cluster in file chain has changed */
-			assert(0);
-			copy_it = 1;
-		    } else if (offset == 0) {
-			const char* basename = get_basename(mapping->path);
-
-			if (strcmp(basename, basename2))
-			    copy_it = 1;
-			first_mapping_index = array_index(&(s->mapping), mapping);
-		    }
-
-		    if (mapping->first_mapping_index != first_mapping_index
-			    && mapping->info.file.offset > 0) {
-			assert(0);
-			copy_it = 1;
-		    }
-
-		    /* need to write out? */
-		    if (!was_modified && is_file(direntry)) {
-			was_modified = 1;
-			schedule_writeout(s, mapping->dir_index, offset);
-		    }
-		}
-	    }
-
-	    if (copy_it) {
-		int i, dummy;
-		/*
-		 * This is horribly inefficient, but that is okay, since
-		 * it is rarely executed, if at all.
-		 */
-		int64_t offset = cluster2sector(s, cluster_num);
-
-		vvfat_close_current_file(s);
-		for (i = 0; i < s->sectors_per_cluster; i++)
-		    if (!s->qcow->drv->bdrv_is_allocated(s->qcow,
-				offset + i, 1, &dummy)) {
-			if (vvfat_read(s->bs,
-				    offset, s->cluster_buffer, 1))
-			    return -1;
-			if (s->qcow->drv->bdrv_write(s->qcow,
-				    offset, s->cluster_buffer, 1))
-			    return -2;
-		    }
-	    }
-	}
-
-	ret++;
-	if (s->used_clusters[cluster_num] & USED_ANY)
-	    return 0;
-	s->used_clusters[cluster_num] = USED_FILE;
-
-	cluster_num = modified_fat_get(s, cluster_num);
-
-	if (fat_eof(s, cluster_num))
-	    return ret;
-	else if (cluster_num < 2 || cluster_num > s->max_fat_value - 16)
-	    return -1;
-
-	offset += s->cluster_size;
-    }
-}
-
-/*
- * This function looks at the modified data (qcow).
- * It returns 0 upon inconsistency or error, and the number of clusters
- * used by the directory, its subdirectories and their files.
- */
-static int check_directory_consistency(BDRVVVFATState *s,
-	int cluster_num, const char* path)
-{
-    int ret = 0;
-    unsigned char* cluster = qemu_malloc(s->cluster_size);
-    direntry_t* direntries = (direntry_t*)cluster;
-    mapping_t* mapping = find_mapping_for_cluster(s, cluster_num);
-
-    long_file_name lfn;
-    int path_len = strlen(path);
-    char path2[PATH_MAX];
-
-    assert(path_len < PATH_MAX); /* len was tested before! */
-    pstrcpy(path2, sizeof(path2), path);
-    path2[path_len] = '/';
-    path2[path_len + 1] = '\0';
-
-    if (mapping) {
-	const char* basename = get_basename(mapping->path);
-	const char* basename2 = get_basename(path);
-
-	assert(mapping->mode & MODE_DIRECTORY);
-
-	assert(mapping->mode & MODE_DELETED);
-	mapping->mode &= ~MODE_DELETED;
-
-	if (strcmp(basename, basename2))
-	    schedule_rename(s, cluster_num, strdup(path));
-    } else
-	/* new directory */
-	schedule_mkdir(s, cluster_num, strdup(path));
-
-    lfn_init(&lfn);
-    do {
-	int i;
-	int subret = 0;
-
-	ret++;
-
-	if (s->used_clusters[cluster_num] & USED_ANY) {
-	    fprintf(stderr, "cluster %d used more than once\n", (int)cluster_num);
-	    return 0;
-	}
-	s->used_clusters[cluster_num] = USED_DIRECTORY;
-
-DLOG(fprintf(stderr, "read cluster %d (sector %d)\n", (int)cluster_num, (int)cluster2sector(s, cluster_num)));
-	subret = vvfat_read(s->bs, cluster2sector(s, cluster_num), cluster,
-		s->sectors_per_cluster);
-	if (subret) {
-	    fprintf(stderr, "Error fetching direntries\n");
-	fail:
-	    free(cluster);
-	    return 0;
-	}
-
-	for (i = 0; i < 0x10 * s->sectors_per_cluster; i++) {
-	    int cluster_count = 0;
-
-DLOG(fprintf(stderr, "check direntry %d: \n", i); print_direntry(direntries + i));
-	    if (is_volume_label(direntries + i) || is_dot(direntries + i) ||
-		    is_free(direntries + i))
-		continue;
-
-	    subret = parse_long_name(&lfn, direntries + i);
-	    if (subret < 0) {
-		fprintf(stderr, "Error in long name\n");
-		goto fail;
-	    }
-	    if (subret == 0 || is_free(direntries + i))
-		continue;
-
-	    if (fat_chksum(direntries+i) != lfn.checksum) {
-		subret = parse_short_name(s, &lfn, direntries + i);
-		if (subret < 0) {
-		    fprintf(stderr, "Error in short name (%d)\n", subret);
-		    goto fail;
-		}
-		if (subret > 0 || !strcmp((char*)lfn.name, ".")
-			|| !strcmp((char*)lfn.name, ".."))
-		    continue;
-	    }
-	    lfn.checksum = 0x100; /* cannot use long name twice */
-
-	    if (path_len + 1 + lfn.len >= PATH_MAX) {
-		fprintf(stderr, "Name too long: %s/%s\n", path, lfn.name);
-		goto fail;
-	    }
-            pstrcpy(path2 + path_len + 1, sizeof(path2) - path_len - 1,
-                    (char*)lfn.name);
-
-	    if (is_directory(direntries + i)) {
-		if (begin_of_direntry(direntries + i) == 0) {
-		    DLOG(fprintf(stderr, "invalid begin for directory: %s\n", path2); print_direntry(direntries + i));
-		    goto fail;
-		}
-		cluster_count = check_directory_consistency(s,
-			begin_of_direntry(direntries + i), path2);
-		if (cluster_count == 0) {
-		    DLOG(fprintf(stderr, "problem in directory %s:\n", path2); print_direntry(direntries + i));
-		    goto fail;
-		}
-	    } else if (is_file(direntries + i)) {
-		/* check file size with FAT */
-		cluster_count = get_cluster_count_for_direntry(s, direntries + i, path2);
-		if (cluster_count !=
-			(le32_to_cpu(direntries[i].size) + s->cluster_size
-			 - 1) / s->cluster_size) {
-		    DLOG(fprintf(stderr, "Cluster count mismatch\n"));
-		    goto fail;
-		}
-	    } else
-		assert(0); /* cluster_count = 0; */
-
-	    ret += cluster_count;
-	}
-
-	cluster_num = modified_fat_get(s, cluster_num);
-    } while(!fat_eof(s, cluster_num));
-
-    free(cluster);
-    return ret;
-}
-
-/* returns 1 on success */
-static int is_consistent(BDRVVVFATState* s)
-{
-    int i, check;
-    int used_clusters_count = 0;
-
-DLOG(checkpoint());
-    /*
-     * - get modified FAT
-     * - compare the two FATs (TODO)
-     * - get buffer for marking used clusters
-     * - recurse direntries from root (using bs->bdrv_read to make
-     *    sure to get the new data)
-     *   - check that the FAT agrees with the size
-     *   - count the number of clusters occupied by this directory and
-     *     its files
-     * - check that the cumulative used cluster count agrees with the
-     *   FAT
-     * - if all is fine, return number of used clusters
-     */
-    if (s->fat2 == NULL) {
-	int size = 0x200 * s->sectors_per_fat;
-	s->fat2 = qemu_malloc(size);
-	memcpy(s->fat2, s->fat.pointer, size);
-    }
-    check = vvfat_read(s->bs,
-	    s->first_sectors_number, s->fat2, s->sectors_per_fat);
-    if (check) {
-	fprintf(stderr, "Could not copy fat\n");
-	return 0;
-    }
-    assert (s->used_clusters);
-    for (i = 0; i < sector2cluster(s, s->sector_count); i++)
-	s->used_clusters[i] &= ~USED_ANY;
-
-    clear_commits(s);
-
-    /* mark every mapped file/directory as deleted.
-     * (check_directory_consistency() will unmark those still present). */
-    if (s->qcow)
-	for (i = 0; i < s->mapping.next; i++) {
-	    mapping_t* mapping = array_get(&(s->mapping), i);
-	    if (mapping->first_mapping_index < 0)
-		mapping->mode |= MODE_DELETED;
-	}
-
-    used_clusters_count = check_directory_consistency(s, 0, s->path);
-    if (used_clusters_count <= 0) {
-	DLOG(fprintf(stderr, "problem in directory\n"));
-	return 0;
-    }
-
-    check = s->last_cluster_of_root_directory;
-    for (i = check; i < sector2cluster(s, s->sector_count); i++) {
-	if (modified_fat_get(s, i)) {
-	    if(!s->used_clusters[i]) {
-		DLOG(fprintf(stderr, "FAT was modified (%d), but cluster is not used?\n", i));
-		return 0;
-	    }
-	    check++;
-	}
-
-	if (s->used_clusters[i] == USED_ALLOCATED) {
-	    /* allocated, but not used... */
-	    DLOG(fprintf(stderr, "unused, modified cluster: %d\n", i));
-	    return 0;
-	}
-    }
-
-    if (check != used_clusters_count)
-	return 0;
-
-    return used_clusters_count;
-}
-
-static inline void adjust_mapping_indices(BDRVVVFATState* s,
-	int offset, int adjust)
-{
-    int i;
-
-    for (i = 0; i < s->mapping.next; i++) {
-	mapping_t* mapping = array_get(&(s->mapping), i);
-
-#define ADJUST_MAPPING_INDEX(name) \
-	if (mapping->name >= offset) \
-	    mapping->name += adjust
-
-	ADJUST_MAPPING_INDEX(first_mapping_index);
-	if (mapping->mode & MODE_DIRECTORY)
-	    ADJUST_MAPPING_INDEX(info.dir.parent_mapping_index);
-    }
-}
-
-/* insert or update mapping */
-static mapping_t* insert_mapping(BDRVVVFATState* s,
-	uint32_t begin, uint32_t end)
-{
-    /*
-     * - find mapping where mapping->begin >= begin,
-     * - if mapping->begin > begin: insert
-     *   - adjust all references to mappings!
-     * - else: adjust
-     * - replace name
-     */
-    int index = find_mapping_for_cluster_aux(s, begin, 0, s->mapping.next);
-    mapping_t* mapping = NULL;
-    mapping_t* first_mapping = array_get(&(s->mapping), 0);
-
-    if (index < s->mapping.next && (mapping = array_get(&(s->mapping), index))
-	    && mapping->begin < begin) {
-	mapping->end = begin;
-	index++;
-	mapping = array_get(&(s->mapping), index);
-    }
-    if (index >= s->mapping.next || mapping->begin > begin) {
-	mapping = array_insert(&(s->mapping), index, 1);
-	mapping->path = NULL;
-	adjust_mapping_indices(s, index, +1);
-    }
-
-    mapping->begin = begin;
-    mapping->end = end;
-
-DLOG(mapping_t* next_mapping;
-assert(index + 1 >= s->mapping.next ||
-((next_mapping = array_get(&(s->mapping), index + 1)) &&
- next_mapping->begin >= end)));
-
-    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
-	s->current_mapping = array_get(&(s->mapping),
-		s->current_mapping - first_mapping);
-
-    return mapping;
-}
-
-static int remove_mapping(BDRVVVFATState* s, int mapping_index)
-{
-    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
-    mapping_t* first_mapping = array_get(&(s->mapping), 0);
-
-    /* free mapping */
-    if (mapping->first_mapping_index < 0)
-	free(mapping->path);
-
-    /* remove from s->mapping */
-    array_remove(&(s->mapping), mapping_index);
-
-    /* adjust all references to mappings */
-    adjust_mapping_indices(s, mapping_index, -1);
-
-    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
-	s->current_mapping = array_get(&(s->mapping),
-		s->current_mapping - first_mapping);
-
-    return 0;
-}
-
-static void adjust_dirindices(BDRVVVFATState* s, int offset, int adjust)
-{
-    int i;
-    for (i = 0; i < s->mapping.next; i++) {
-	mapping_t* mapping = array_get(&(s->mapping), i);
-	if (mapping->dir_index >= offset)
-	    mapping->dir_index += adjust;
-	if ((mapping->mode & MODE_DIRECTORY) &&
-		mapping->info.dir.first_dir_index >= offset)
-	    mapping->info.dir.first_dir_index += adjust;
-    }
-}
-
-static direntry_t* insert_direntries(BDRVVVFATState* s,
-	int dir_index, int count)
-{
-    /*
-     * make room in s->directory,
-     * adjust_dirindices
-     */
-    direntry_t* result = array_insert(&(s->directory), dir_index, count);
-    if (result == NULL)
-	return NULL;
-    adjust_dirindices(s, dir_index, count);
-    return result;
-}
-
-static int remove_direntries(BDRVVVFATState* s, int dir_index, int count)
-{
-    int ret = array_remove_slice(&(s->directory), dir_index, count);
-    if (ret)
-	return ret;
-    adjust_dirindices(s, dir_index, -count);
-    return 0;
-}
-
-/*
- * Adapt the mappings of the cluster chain starting at first cluster
- * (i.e. if a file starts at first_cluster, the chain is followed according
- * to the modified fat, and the corresponding entries in s->mapping are
- * adjusted)
- */
-static int commit_mappings(BDRVVVFATState* s,
-	uint32_t first_cluster, int dir_index)
-{
-    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
-    direntry_t* direntry = array_get(&(s->directory), dir_index);
-    uint32_t cluster = first_cluster;
-
-    vvfat_close_current_file(s);
-
-    assert(mapping);
-    assert(mapping->begin == first_cluster);
-    mapping->first_mapping_index = -1;
-    mapping->dir_index = dir_index;
-    mapping->mode = (dir_index <= 0 || is_directory(direntry)) ?
-	MODE_DIRECTORY : MODE_NORMAL;
-
-    while (!fat_eof(s, cluster)) {
-	uint32_t c, c1;
-
-	for (c = cluster, c1 = modified_fat_get(s, c); c + 1 == c1;
-		c = c1, c1 = modified_fat_get(s, c1));
-
-	c++;
-	if (c > mapping->end) {
-	    int index = array_index(&(s->mapping), mapping);
-	    int i, max_i = s->mapping.next - index;
-	    for (i = 1; i < max_i && mapping[i].begin < c; i++);
-	    while (--i > 0)
-		remove_mapping(s, index + 1);
-	}
-	assert(mapping == array_get(&(s->mapping), s->mapping.next - 1)
-		|| mapping[1].begin >= c);
-	mapping->end = c;
-
-	if (!fat_eof(s, c1)) {
-	    int i = find_mapping_for_cluster_aux(s, c1, 0, s->mapping.next);
-	    mapping_t* next_mapping = i >= s->mapping.next ? NULL :
-		array_get(&(s->mapping), i);
-
-	    if (next_mapping == NULL || next_mapping->begin > c1) {
-		int i1 = array_index(&(s->mapping), mapping);
-
-		next_mapping = insert_mapping(s, c1, c1+1);
-
-		if (c1 < c)
-		    i1++;
-		mapping = array_get(&(s->mapping), i1);
-	    }
-
-	    next_mapping->dir_index = mapping->dir_index;
-	    next_mapping->first_mapping_index =
-		mapping->first_mapping_index < 0 ?
-		array_index(&(s->mapping), mapping) :
-		mapping->first_mapping_index;
-	    next_mapping->path = mapping->path;
-	    next_mapping->mode = mapping->mode;
-	    next_mapping->read_only = mapping->read_only;
-	    if (mapping->mode & MODE_DIRECTORY) {
-		next_mapping->info.dir.parent_mapping_index =
-			mapping->info.dir.parent_mapping_index;
-		next_mapping->info.dir.first_dir_index =
-			mapping->info.dir.first_dir_index +
-			0x10 * s->sectors_per_cluster *
-			(mapping->end - mapping->begin);
-	    } else
-		next_mapping->info.file.offset = mapping->info.file.offset +
-			mapping->end - mapping->begin;
-
-	    mapping = next_mapping;
-	}
-
-	cluster = c1;
-    }
-
-    return 0;
-}
-
-static int commit_direntries(BDRVVVFATState* s,
-	int dir_index, int parent_mapping_index)
-{
-    direntry_t* direntry = array_get(&(s->directory), dir_index);
-    uint32_t first_cluster = dir_index == 0 ? 0 : begin_of_direntry(direntry);
-    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
-
-    int factor = 0x10 * s->sectors_per_cluster;
-    int old_cluster_count, new_cluster_count;
-    int current_dir_index = mapping->info.dir.first_dir_index;
-    int first_dir_index = current_dir_index;
-    int ret, i;
-    uint32_t c;
-
-DLOG(fprintf(stderr, "commit_direntries for %s, parent_mapping_index %d\n", mapping->path, parent_mapping_index));
-
-    assert(direntry);
-    assert(mapping);
-    assert(mapping->begin == first_cluster);
-    assert(mapping->info.dir.first_dir_index < s->directory.next);
-    assert(mapping->mode & MODE_DIRECTORY);
-    assert(dir_index == 0 || is_directory(direntry));
-
-    mapping->info.dir.parent_mapping_index = parent_mapping_index;
-
-    if (first_cluster == 0) {
-	old_cluster_count = new_cluster_count =
-	    s->last_cluster_of_root_directory;
-    } else {
-	for (old_cluster_count = 0, c = first_cluster; !fat_eof(s, c);
-		c = fat_get(s, c))
-	    old_cluster_count++;
-
-	for (new_cluster_count = 0, c = first_cluster; !fat_eof(s, c);
-		c = modified_fat_get(s, c))
-	    new_cluster_count++;
-    }
-
-    if (new_cluster_count > old_cluster_count) {
-	if (insert_direntries(s,
-		current_dir_index + factor * old_cluster_count,
-		factor * (new_cluster_count - old_cluster_count)) == NULL)
-	    return -1;
-    } else if (new_cluster_count < old_cluster_count)
-	remove_direntries(s,
-		current_dir_index + factor * new_cluster_count,
-		factor * (old_cluster_count - new_cluster_count));
-
-    for (c = first_cluster; !fat_eof(s, c); c = modified_fat_get(s, c)) {
-	void* direntry = array_get(&(s->directory), current_dir_index);
-	int ret = vvfat_read(s->bs, cluster2sector(s, c), direntry,
-		s->sectors_per_cluster);
-	if (ret)
-	    return ret;
-	assert(!strncmp(s->directory.pointer, "QEMU", 4));
-	current_dir_index += factor;
-    }
-
-    ret = commit_mappings(s, first_cluster, dir_index);
-    if (ret)
-	return ret;
-
-    /* recurse */
-    for (i = 0; i < factor * new_cluster_count; i++) {
-	direntry = array_get(&(s->directory), first_dir_index + i);
-	if (is_directory(direntry) && !is_dot(direntry)) {
-	    mapping = find_mapping_for_cluster(s, first_cluster);
-	    assert(mapping->mode & MODE_DIRECTORY);
-	    ret = commit_direntries(s, first_dir_index + i,
-		array_index(&(s->mapping), mapping));
-	    if (ret)
-		return ret;
-	}
-    }
-
-    return 0;
-}
-
-/* commit one file (adjust contents, adjust mapping),
-   return first_mapping_index */
-static int commit_one_file(BDRVVVFATState* s,
-	int dir_index, uint32_t offset)
-{
-    direntry_t* direntry = array_get(&(s->directory), dir_index);
-    uint32_t c = begin_of_direntry(direntry);
-    uint32_t first_cluster = c;
-    mapping_t* mapping = find_mapping_for_cluster(s, c);
-    uint32_t size = filesize_of_direntry(direntry);
-    char* cluster = qemu_malloc(s->cluster_size);
-    uint32_t i;
-    int fd = 0;
-
-    assert(offset < size);
-    assert((offset % s->cluster_size) == 0);
-
-    for (i = s->cluster_size; i < offset; i += s->cluster_size)
-	c = modified_fat_get(s, c);
-
-    fd = open(mapping->path, O_RDWR | O_CREAT | O_BINARY, 0666);
-    if (fd < 0) {
-	fprintf(stderr, "Could not open %s... (%s, %d)\n", mapping->path,
-		strerror(errno), errno);
-	return fd;
-    }
-    if (offset > 0)
-	if (lseek(fd, offset, SEEK_SET) != offset)
-	    return -3;
-
-    while (offset < size) {
-	uint32_t c1;
-	int rest_size = (size - offset > s->cluster_size ?
-		s->cluster_size : size - offset);
-	int ret;
-
-	c1 = modified_fat_get(s, c);
-
-	assert((size - offset == 0 && fat_eof(s, c)) ||
-		(size > offset && c >=2 && !fat_eof(s, c)));
-
-	ret = vvfat_read(s->bs, cluster2sector(s, c),
-	    (uint8_t*)cluster, (rest_size + 0x1ff) / 0x200);
-
-	if (ret < 0)
-	    return ret;
-
-	if (write(fd, cluster, rest_size) < 0)
-	    return -2;
-
-	offset += rest_size;
-	c = c1;
-    }
-
-    ftruncate(fd, size);
-    close(fd);
-
-    return commit_mappings(s, first_cluster, dir_index);
-}
-
-#ifdef DEBUG
-/* test, if all mappings point to valid direntries */
-static void check1(BDRVVVFATState* s)
-{
-    int i;
-    for (i = 0; i < s->mapping.next; i++) {
-	mapping_t* mapping = array_get(&(s->mapping), i);
-	if (mapping->mode & MODE_DELETED) {
-	    fprintf(stderr, "deleted\n");
-	    continue;
-	}
-	assert(mapping->dir_index >= 0);
-	assert(mapping->dir_index < s->directory.next);
-	direntry_t* direntry = array_get(&(s->directory), mapping->dir_index);
-	assert(mapping->begin == begin_of_direntry(direntry) || mapping->first_mapping_index >= 0);
-	if (mapping->mode & MODE_DIRECTORY) {
-	    assert(mapping->info.dir.first_dir_index + 0x10 * s->sectors_per_cluster * (mapping->end - mapping->begin) <= s->directory.next);
-	    assert((mapping->info.dir.first_dir_index % (0x10 * s->sectors_per_cluster)) == 0);
-	}
-    }
-}
-
-/* test, if all direntries have mappings */
-static void check2(BDRVVVFATState* s)
-{
-    int i;
-    int first_mapping = -1;
-
-    for (i = 0; i < s->directory.next; i++) {
-	direntry_t* direntry = array_get(&(s->directory), i);
-
-	if (is_short_name(direntry) && begin_of_direntry(direntry)) {
-	    mapping_t* mapping = find_mapping_for_cluster(s, begin_of_direntry(direntry));
-	    assert(mapping);
-	    assert(mapping->dir_index == i || is_dot(direntry));
-	    assert(mapping->begin == begin_of_direntry(direntry) || is_dot(direntry));
-	}
-
-	if ((i % (0x10 * s->sectors_per_cluster)) == 0) {
-	    /* cluster start */
-	    int j, count = 0;
-
-	    for (j = 0; j < s->mapping.next; j++) {
-		mapping_t* mapping = array_get(&(s->mapping), j);
-		if (mapping->mode & MODE_DELETED)
-		    continue;
-		if (mapping->mode & MODE_DIRECTORY) {
-		    if (mapping->info.dir.first_dir_index <= i && mapping->info.dir.first_dir_index + 0x10 * s->sectors_per_cluster > i) {
-			assert(++count == 1);
-			if (mapping->first_mapping_index == -1)
-			    first_mapping = array_index(&(s->mapping), mapping);
-			else
-			    assert(first_mapping == mapping->first_mapping_index);
-			if (mapping->info.dir.parent_mapping_index < 0)
-			    assert(j == 0);
-			else {
-			    mapping_t* parent = array_get(&(s->mapping), mapping->info.dir.parent_mapping_index);
-			    assert(parent->mode & MODE_DIRECTORY);
-			    assert(parent->info.dir.first_dir_index < mapping->info.dir.first_dir_index);
-			}
-		    }
-		}
-	    }
-	    if (count == 0)
-		first_mapping = -1;
-	}
-    }
-}
-#endif
-
-static int handle_renames_and_mkdirs(BDRVVVFATState* s)
-{
-    int i;
-
-#ifdef DEBUG
-    fprintf(stderr, "handle_renames\n");
-    for (i = 0; i < s->commits.next; i++) {
-	commit_t* commit = array_get(&(s->commits), i);
-	fprintf(stderr, "%d, %s (%d, %d)\n", i, commit->path ? commit->path : "(null)", commit->param.rename.cluster, commit->action);
-    }
-#endif
-
-    for (i = 0; i < s->commits.next;) {
-	commit_t* commit = array_get(&(s->commits), i);
-	if (commit->action == ACTION_RENAME) {
-	    mapping_t* mapping = find_mapping_for_cluster(s,
-		    commit->param.rename.cluster);
-	    char* old_path = mapping->path;
-
-	    assert(commit->path);
-	    mapping->path = commit->path;
-	    if (rename(old_path, mapping->path))
-		return -2;
-
-	    if (mapping->mode & MODE_DIRECTORY) {
-		int l1 = strlen(mapping->path);
-		int l2 = strlen(old_path);
-		int diff = l1 - l2;
-		direntry_t* direntry = array_get(&(s->directory),
-			mapping->info.dir.first_dir_index);
-		uint32_t c = mapping->begin;
-		int i = 0;
-
-		/* recurse */
-		while (!fat_eof(s, c)) {
-		    do {
-			direntry_t* d = direntry + i;
-
-			if (is_file(d) || (is_directory(d) && !is_dot(d))) {
-			    mapping_t* m = find_mapping_for_cluster(s,
-				    begin_of_direntry(d));
-			    int l = strlen(m->path);
-			    char* new_path = qemu_malloc(l + diff + 1);
-
-			    assert(!strncmp(m->path, mapping->path, l2));
-
-                            pstrcpy(new_path, l + diff + 1, mapping->path);
-                            pstrcpy(new_path + l1, l + diff + 1 - l1,
-                                    m->path + l2);
-
-			    schedule_rename(s, m->begin, new_path);
-			}
-			i++;
-		    } while((i % (0x10 * s->sectors_per_cluster)) != 0);
-		    c = fat_get(s, c);
-		}
-	    }
-
-	    free(old_path);
-	    array_remove(&(s->commits), i);
-	    continue;
-	} else if (commit->action == ACTION_MKDIR) {
-	    mapping_t* mapping;
-	    int j, parent_path_len;
-
-#ifdef __MINGW32__
-            if (mkdir(commit->path))
-                return -5;
-#else
-            if (mkdir(commit->path, 0755))
-                return -5;
-#endif
-
-	    mapping = insert_mapping(s, commit->param.mkdir.cluster,
-		    commit->param.mkdir.cluster + 1);
-	    if (mapping == NULL)
-		return -6;
-
-	    mapping->mode = MODE_DIRECTORY;
-	    mapping->read_only = 0;
-	    mapping->path = commit->path;
-	    j = s->directory.next;
-	    assert(j);
-	    insert_direntries(s, s->directory.next,
-		    0x10 * s->sectors_per_cluster);
-	    mapping->info.dir.first_dir_index = j;
-
-	    parent_path_len = strlen(commit->path)
-		- strlen(get_basename(commit->path)) - 1;
-	    for (j = 0; j < s->mapping.next; j++) {
-		mapping_t* m = array_get(&(s->mapping), j);
-		if (m->first_mapping_index < 0 && m != mapping &&
-			!strncmp(m->path, mapping->path, parent_path_len) &&
-			strlen(m->path) == parent_path_len)
-		    break;
-	    }
-	    assert(j < s->mapping.next);
-	    mapping->info.dir.parent_mapping_index = j;
-
-	    array_remove(&(s->commits), i);
-	    continue;
-	}
-
-	i++;
-    }
-    return 0;
-}
-
-/*
- * TODO: make sure that the short name is not matching *another* file
- */
-static int handle_commits(BDRVVVFATState* s)
-{
-    int i, fail = 0;
-
-    vvfat_close_current_file(s);
-
-    for (i = 0; !fail && i < s->commits.next; i++) {
-	commit_t* commit = array_get(&(s->commits), i);
-	switch(commit->action) {
-	case ACTION_RENAME: case ACTION_MKDIR:
-	    assert(0);
-	    fail = -2;
-	    break;
-	case ACTION_WRITEOUT: {
-	    direntry_t* entry = array_get(&(s->directory),
-		    commit->param.writeout.dir_index);
-	    uint32_t begin = begin_of_direntry(entry);
-	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
-
-	    assert(mapping);
-	    assert(mapping->begin == begin);
-	    assert(commit->path == NULL);
-
-	    if (commit_one_file(s, commit->param.writeout.dir_index,
-			commit->param.writeout.modified_offset))
-		fail = -3;
-
-	    break;
-	}
-	case ACTION_NEW_FILE: {
-	    int begin = commit->param.new_file.first_cluster;
-	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
-	    direntry_t* entry;
-	    int i;
-
-	    /* find direntry */
-	    for (i = 0; i < s->directory.next; i++) {
-		entry = array_get(&(s->directory), i);
-		if (is_file(entry) && begin_of_direntry(entry) == begin)
-		    break;
-	    }
-
-	    if (i >= s->directory.next) {
-		fail = -6;
-		continue;
-	    }
-
-	    /* make sure there exists an initial mapping */
-	    if (mapping && mapping->begin != begin) {
-		mapping->end = begin;
-		mapping = NULL;
-	    }
-	    if (mapping == NULL) {
-		mapping = insert_mapping(s, begin, begin+1);
-	    }
-	    /* most members will be fixed in commit_mappings() */
-	    assert(commit->path);
-	    mapping->path = commit->path;
-	    mapping->read_only = 0;
-	    mapping->mode = MODE_NORMAL;
-	    mapping->info.file.offset = 0;
-
-	    if (commit_one_file(s, i, 0))
-		fail = -7;
-
-	    break;
-	}
-	default:
-	    assert(0);
-	}
-    }
-    if (i > 0 && array_remove_slice(&(s->commits), 0, i))
-	return -1;
-    return fail;
-}
-
-static int handle_deletes(BDRVVVFATState* s)
-{
-    int i, deferred = 1, deleted = 1;
-
-    /* delete files corresponding to mappings marked as deleted */
-    /* handle DELETEs and unused mappings (modified_fat_get(s, mapping->begin) == 0) */
-    while (deferred && deleted) {
-	deferred = 0;
-	deleted = 0;
-
-	for (i = 1; i < s->mapping.next; i++) {
-	    mapping_t* mapping = array_get(&(s->mapping), i);
-	    if (mapping->mode & MODE_DELETED) {
-		direntry_t* entry = array_get(&(s->directory),
-			mapping->dir_index);
-
-		if (is_free(entry)) {
-		    /* remove file/directory */
-		    if (mapping->mode & MODE_DIRECTORY) {
-			int j, next_dir_index = s->directory.next,
-			first_dir_index = mapping->info.dir.first_dir_index;
-
-			if (rmdir(mapping->path) < 0) {
-			    if (errno == ENOTEMPTY) {
-				deferred++;
-				continue;
-			    } else
-				return -5;
-			}
-
-			for (j = 1; j < s->mapping.next; j++) {
-			    mapping_t* m = array_get(&(s->mapping), j);
-			    if (m->mode & MODE_DIRECTORY &&
-				    m->info.dir.first_dir_index >
-				    first_dir_index &&
-				    m->info.dir.first_dir_index <
-				    next_dir_index)
-				next_dir_index =
-				    m->info.dir.first_dir_index;
-			}
-			remove_direntries(s, first_dir_index,
-				next_dir_index - first_dir_index);
-
-			deleted++;
-		    }
-		} else {
-		    if (unlink(mapping->path))
-			return -4;
-		    deleted++;
-		}
-		DLOG(fprintf(stderr, "DELETE (%d)\n", i); print_mapping(mapping); print_direntry(entry));
-		remove_mapping(s, i);
-	    }
-	}
-    }
-
-    return 0;
-}
-
-/*
- * synchronize mapping with new state:
- *
- * - copy FAT (with bdrv_read)
- * - mark all filenames corresponding to mappings as deleted
- * - recurse direntries from root (using bs->bdrv_read)
- * - delete files corresponding to mappings marked as deleted
- */
-static int do_commit(BDRVVVFATState* s)
-{
-    int ret = 0;
-
-    /* the real meat are the commits. Nothing to do? Move along! */
-    if (s->commits.next == 0)
-	return 0;
-
-    vvfat_close_current_file(s);
-
-    ret = handle_renames_and_mkdirs(s);
-    if (ret) {
-	fprintf(stderr, "Error handling renames (%d)\n", ret);
-	assert(0);
-	return ret;
-    }
-
-    /* copy FAT (with bdrv_read) */
-    memcpy(s->fat.pointer, s->fat2, 0x200 * s->sectors_per_fat);
-
-    /* recurse direntries from root (using bs->bdrv_read) */
-    ret = commit_direntries(s, 0, -1);
-    if (ret) {
-	fprintf(stderr, "Fatal: error while committing (%d)\n", ret);
-	assert(0);
-	return ret;
-    }
-
-    ret = handle_commits(s);
-    if (ret) {
-	fprintf(stderr, "Error handling commits (%d)\n", ret);
-	assert(0);
-	return ret;
-    }
-
-    ret = handle_deletes(s);
-    if (ret) {
-	fprintf(stderr, "Error deleting\n");
-        assert(0);
-	return ret;
-    }
-
-    s->qcow->drv->bdrv_make_empty(s->qcow);
-
-    memset(s->used_clusters, 0, sector2cluster(s, s->sector_count));
-
-DLOG(checkpoint());
-    return 0;
-}
-
-static int try_commit(BDRVVVFATState* s)
-{
-    vvfat_close_current_file(s);
-DLOG(checkpoint());
-    if(!is_consistent(s))
-	return -1;
-    return do_commit(s);
-}
-
-static int vvfat_write(BlockDriverState *bs, int64_t sector_num,
-                    const uint8_t *buf, int nb_sectors)
-{
-    BDRVVVFATState *s = bs->opaque;
-    int i, ret;
-
-DLOG(checkpoint());
-
-    vvfat_close_current_file(s);
-
-    /*
-     * Some sanity checks:
-     * - do not allow writing to the boot sector
-     * - do not allow to write non-ASCII filenames
-     */
-
-    if (sector_num < s->first_sectors_number)
-	return -1;
-
-    for (i = sector2cluster(s, sector_num);
-	    i <= sector2cluster(s, sector_num + nb_sectors - 1);) {
-	mapping_t* mapping = find_mapping_for_cluster(s, i);
-	if (mapping) {
-	    if (mapping->read_only) {
-		fprintf(stderr, "Tried to write to write-protected file %s\n",
-			mapping->path);
-		return -1;
-	    }
-
-	    if (mapping->mode & MODE_DIRECTORY) {
-		int begin = cluster2sector(s, i);
-		int end = begin + s->sectors_per_cluster, k;
-		int dir_index;
-		const direntry_t* direntries;
-		long_file_name lfn;
-
-		lfn_init(&lfn);
-
-		if (begin < sector_num)
-		    begin = sector_num;
-		if (end > sector_num + nb_sectors)
-		    end = sector_num + nb_sectors;
-		dir_index  = mapping->dir_index +
-		    0x10 * (begin - mapping->begin * s->sectors_per_cluster);
-		direntries = (direntry_t*)(buf + 0x200 * (begin - sector_num));
-
-		for (k = 0; k < (end - begin) * 0x10; k++) {
-		    /* do not allow non-ASCII filenames */
-		    if (parse_long_name(&lfn, direntries + k) < 0) {
-			fprintf(stderr, "Warning: non-ASCII filename\n");
-			return -1;
-		    }
-		    /* no access to the direntry of a read-only file */
-		    else if (is_short_name(direntries+k) &&
-			    (direntries[k].attributes & 1)) {
-			if (memcmp(direntries + k,
-				    array_get(&(s->directory), dir_index + k),
-				    sizeof(direntry_t))) {
-			    fprintf(stderr, "Warning: tried to write to write-protected file\n");
-			    return -1;
-			}
-		    }
-		}
-	    }
-	    i = mapping->end;
-	} else
-	    i++;
-    }
-
-    /*
-     * Use qcow backend. Commit later.
-     */
-DLOG(fprintf(stderr, "Write to qcow backend: %d + %d\n", (int)sector_num, nb_sectors));
-    ret = s->qcow->drv->bdrv_write(s->qcow, sector_num, buf, nb_sectors);
-    if (ret < 0) {
-	fprintf(stderr, "Error writing to qcow backend\n");
-	return ret;
-    }
-
-    for (i = sector2cluster(s, sector_num);
-	    i <= sector2cluster(s, sector_num + nb_sectors - 1); i++)
-	if (i >= 0)
-	    s->used_clusters[i] |= USED_ALLOCATED;
-
-DLOG(checkpoint());
-    /* TODO: add timeout */
-    try_commit(s);
-
-DLOG(checkpoint());
-    return 0;
-}
-
-static int vvfat_is_allocated(BlockDriverState *bs,
-	int64_t sector_num, int nb_sectors, int* n)
-{
-    BDRVVVFATState* s = bs->opaque;
-    *n = s->sector_count - sector_num;
-    if (*n > nb_sectors)
-	*n = nb_sectors;
-    else if (*n < 0)
-	return 0;
-    return 1;
-}
-
-static int write_target_commit(BlockDriverState *bs, int64_t sector_num,
-	const uint8_t* buffer, int nb_sectors) {
-    BDRVVVFATState* s = bs->opaque;
-    return try_commit(s);
-}
-
-static void write_target_close(BlockDriverState *bs) {
-    BDRVVVFATState* s = bs->opaque;
-    bdrv_delete(s->qcow);
-    free(s->qcow_filename);
-}
-
-static BlockDriver vvfat_write_target = {
-    "vvfat_write_target", 0, NULL, NULL, NULL,
-    write_target_commit,
-    write_target_close,
-    NULL, NULL, NULL
-};
-
-static int enable_write_target(BDRVVVFATState *s)
-{
-    int size = sector2cluster(s, s->sector_count);
-    s->used_clusters = calloc(size, 1);
-
-    array_init(&(s->commits), sizeof(commit_t));
-
-    s->qcow_filename = qemu_malloc(1024);
-    get_tmp_filename(s->qcow_filename, 1024);
-    if (bdrv_create(bdrv_find_format("qcow"),
-		s->qcow_filename, s->sector_count, "fat:", 0) < 0)
-	return -1;
-    s->qcow = bdrv_new("");
-    if (s->qcow == NULL || bdrv_open(s->qcow, s->qcow_filename, 0) < 0)
-	return -1;
-
-#ifndef _WIN32
-    unlink(s->qcow_filename);
-#endif
-
-    s->bs->backing_hd = calloc(sizeof(BlockDriverState), 1);
-    s->bs->backing_hd->drv = &vvfat_write_target;
-    s->bs->backing_hd->opaque = s;
-
-    return 0;
-}
-
-static void vvfat_close(BlockDriverState *bs)
-{
-    BDRVVVFATState *s = bs->opaque;
-
-    vvfat_close_current_file(s);
-    array_free(&(s->fat));
-    array_free(&(s->directory));
-    array_free(&(s->mapping));
-    if(s->cluster_buffer)
-        free(s->cluster_buffer);
-}
-
-static BlockDriver bdrv_vvfat = {
-    .format_name	= "vvfat",
-    .instance_size	= sizeof(BDRVVVFATState),
-    .bdrv_open		= vvfat_open,
-    .bdrv_read		= vvfat_read,
-    .bdrv_write		= vvfat_write,
-    .bdrv_close		= vvfat_close,
-    .bdrv_is_allocated	= vvfat_is_allocated,
-    .protocol_name	= "fat",
-};
-
-static void bdrv_vvfat_init(void)
-{
-    bdrv_register(&bdrv_vvfat);
-}
-
-block_init(bdrv_vvfat_init);
-
-#ifdef DEBUG
-static void checkpoint(void) {
-    assert(((mapping_t*)array_get(&(vvv->mapping), 0))->end == 2);
-    check1(vvv);
-    check2(vvv);
-    assert(!vvv->current_mapping || vvv->current_fd || (vvv->current_mapping->mode & MODE_DIRECTORY));
-#if 0
-    if (((direntry_t*)vvv->directory.pointer)[1].attributes != 0xf)
-	fprintf(stderr, "Nonono!\n");
-    mapping_t* mapping;
-    direntry_t* direntry;
-    assert(vvv->mapping.size >= vvv->mapping.item_size * vvv->mapping.next);
-    assert(vvv->directory.size >= vvv->directory.item_size * vvv->directory.next);
-    if (vvv->mapping.next<47)
-	return;
-    assert((mapping = array_get(&(vvv->mapping), 47)));
-    assert(mapping->dir_index < vvv->directory.next);
-    direntry = array_get(&(vvv->directory), mapping->dir_index);
-    assert(!memcmp(direntry->name, "USB     H  ", 11) || direntry->name[0]==0);
-#endif
-    return;
-    /* avoid compiler warnings: */
-    hexdump(NULL, 100);
-    remove_mapping(vvv, NULL);
-    print_mapping(NULL);
-    print_direntry(NULL);
-}
-#endif