vvfat.c 86.7 KB
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/* vim:set shiftwidth=4 ts=4: */
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/*
 * QEMU Block driver for virtual VFAT (shadows a local directory)
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 *
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 * Copyright (c) 2004,2005 Johannes E. Schindelin
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 *
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 * 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.
 */
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#include "qemu/osdep.h"
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#include <dirent.h>
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#include "qapi/error.h"
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#include "block/block_int.h"
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#include "qemu/module.h"
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#include "qemu/bswap.h"
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#include "migration/migration.h"
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#include "qapi/qmp/qint.h"
#include "qapi/qmp/qbool.h"
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#include "qapi/qmp/qstring.h"
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#include "qemu/cutils.h"
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#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
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    Note that DOS assumes the system files to be the first files in the
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    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

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static void checkpoint(void);
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#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
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#define assert(a) do {if (!(a)) nonono(__FILE__, __LINE__, #a);}while(0)
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#endif

#else

#define DLOG(a)

#endif
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/* dynamic array functions */
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typedef struct array_t {
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    char* pointer;
    unsigned int size,next,item_size;
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} array_t;
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static inline void array_init(array_t* array,unsigned int item_size)
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{
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    array->pointer = NULL;
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    array->size=0;
    array->next=0;
    array->item_size=item_size;
}

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static inline void array_free(array_t* array)
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{
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    g_free(array->pointer);
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    array->size=array->next=0;
}

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/* does not automatically grow */
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static inline void* array_get(array_t* array,unsigned int index) {
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    assert(index < array->next);
    return array->pointer + index * array->item_size;
}

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static inline int array_ensure_allocated(array_t* array, int index)
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{
    if((index + 1) * array->item_size > array->size) {
	int new_size = (index + 32) * array->item_size;
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	array->pointer = g_realloc(array->pointer, new_size);
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	if (!array->pointer)
	    return -1;
	array->size = new_size;
	array->next = index + 1;
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    }
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    return 0;
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}

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static inline void* array_get_next(array_t* array) {
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    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);

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    return result;
}

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static inline void* array_insert(array_t* array,unsigned int index,unsigned int count) {
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    if((array->next+count)*array->item_size>array->size) {
	int increment=count*array->item_size;
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	array->pointer=g_realloc(array->pointer,array->size+increment);
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	if(!array->pointer)
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            return NULL;
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	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. */
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static inline int array_roll(array_t* array,int index_to,int index_from,int count)
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{
    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;
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    if(index_to==index_from)
	return 0;

    is=array->item_size;
    from=array->pointer+index_from*is;
    to=array->pointer+index_to*is;
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    buf=g_malloc(is*count);
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    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);
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    memcpy(to,buf,is*count);

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    g_free(buf);
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    return 0;
}

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static inline int array_remove_slice(array_t* array,int index, int count)
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{
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    assert(index >=0);
    assert(count > 0);
    assert(index + count <= array->next);
    if(array_roll(array,array->next-1,index,count))
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	return -1;
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    array->next -= count;
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    return 0;
}

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static int array_remove(array_t* array,int index)
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{
    return array_remove_slice(array, index, 1);
}

/* return the index for a given member */
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static int array_index(array_t* array, void* pointer)
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{
    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;
}

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/* These structures are used to fake a disk and the VFAT filesystem.
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 * For this reason we need to use QEMU_PACKED. */
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typedef struct bootsector_t {
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    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;
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    uint16_t total_sectors16;
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    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];
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	} QEMU_PACKED fat16;
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	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;
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	} QEMU_PACKED fat32;
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    } u;
    uint8_t fat_type[8];
    uint8_t ignored[0x1c0];
    uint8_t magic[2];
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} QEMU_PACKED bootsector_t;
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typedef struct {
    uint8_t head;
    uint8_t sector;
    uint8_t cylinder;
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} mbr_chs_t;
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typedef struct partition_t {
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    uint8_t attributes; /* 0x80 = bootable */
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    mbr_chs_t start_CHS;
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    uint8_t   fs_type; /* 0x1 = FAT12, 0x6 = FAT16, 0xe = FAT16_LBA, 0xb = FAT32, 0xc = FAT32_LBA */
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    mbr_chs_t end_CHS;
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    uint32_t start_sector_long;
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    uint32_t length_sector_long;
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} QEMU_PACKED partition_t;
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typedef struct mbr_t {
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    uint8_t ignored[0x1b8];
    uint32_t nt_id;
    uint8_t ignored2[2];
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    partition_t partition[4];
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    uint8_t magic[2];
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} QEMU_PACKED mbr_t;
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typedef struct direntry_t {
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    uint8_t name[8 + 3];
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    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;
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} QEMU_PACKED direntry_t;
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/* this structure are used to transparently access the files */

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typedef struct mapping_t {
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    /* begin is the first cluster, end is the last+1 */
    uint32_t begin,end;
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    /* as s->directory is growable, no pointer may be used here */
    unsigned int dir_index;
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    /* 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;
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} mapping_t;
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#ifdef DEBUG
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static void print_direntry(const struct direntry_t*);
static void print_mapping(const struct mapping_t* mapping);
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#endif
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/* here begins the real VVFAT driver */

typedef struct BDRVVVFATState {
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    CoMutex lock;
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    BlockDriverState* bs; /* pointer to parent */
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    unsigned int first_sectors_number; /* 1 for a single partition, 0x40 for a disk with partition table */
    unsigned char first_sectors[0x40*0x200];
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    int fat_type; /* 16 or 32 */
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    array_t fat,directory,mapping;
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    char volume_label[11];
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    unsigned int cluster_size;
    unsigned int sectors_per_cluster;
    unsigned int sectors_per_fat;
    unsigned int sectors_of_root_directory;
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    uint32_t last_cluster_of_root_directory;
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    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;
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    int current_fd;
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    mapping_t* current_mapping;
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    unsigned char* cluster; /* points to current cluster */
    unsigned char* cluster_buffer; /* points to a buffer to hold temp data */
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    unsigned int current_cluster;

    /* write support */
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    BlockDriverState* write_target;
    char* qcow_filename;
    BlockDriverState* qcow;
    void* fat2;
    char* used_clusters;
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    array_t commits;
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    const char* path;
    int downcase_short_names;
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    Error *migration_blocker;
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} BDRVVVFATState;

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/* 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.
 */
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static int sector2CHS(mbr_chs_t *chs, int spos, int cyls, int heads, int secs)
{
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    int head,sector;
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    sector   = spos % secs;  spos /= secs;
    head     = spos % heads; spos /= heads;
    if (spos >= cyls) {
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        /* 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;
}
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static void init_mbr(BDRVVVFATState *s, int cyls, int heads, int secs)
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{
    /* TODO: if the files mbr.img and bootsect.img exist, use them */
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    mbr_t* real_mbr=(mbr_t*)s->first_sectors;
    partition_t* partition = &(real_mbr->partition[0]);
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    int lba;
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    memset(s->first_sectors,0,512);
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    /* Win NT Disk Signature */
    real_mbr->nt_id= cpu_to_le32(0xbe1afdfa);

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    partition->attributes=0x80; /* bootable */
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    /* LBA is used when partition is outside the CHS geometry */
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    lba  = sector2CHS(&partition->start_CHS, s->first_sectors_number - 1,
                     cyls, heads, secs);
    lba |= sector2CHS(&partition->end_CHS,   s->bs->total_sectors - 1,
                     cyls, heads, secs);
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    /*LBA partitions are identified only by start/length_sector_long not by CHS*/
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    partition->start_sector_long  = cpu_to_le32(s->first_sectors_number - 1);
    partition->length_sector_long = cpu_to_le32(s->bs->total_sectors
                                                - s->first_sectors_number + 1);
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    /* FAT12/FAT16/FAT32 */
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    /* 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);
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    real_mbr->magic[0]=0x55; real_mbr->magic[1]=0xaa;
}

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/* direntry functions */

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/* dest is assumed to hold 258 bytes, and pads with 0xffff up to next multiple of 26 */
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static inline int short2long_name(char* dest,const char* src)
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{
    int i;
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    int len;
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    for(i=0;i<129 && src[i];i++) {
        dest[2*i]=src[i];
	dest[2*i+1]=0;
    }
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    len=2*i;
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    dest[2*i]=dest[2*i+1]=0;
    for(i=2*i+2;(i%26);i++)
	dest[i]=0xff;
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    return len;
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}

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static inline direntry_t* create_long_filename(BDRVVVFATState* s,const char* filename)
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{
    char buffer[258];
    int length=short2long_name(buffer,filename),
        number_of_entries=(length+25)/26,i;
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    direntry_t* entry;
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    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);
    }
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    for(i=0;i<26*number_of_entries;i++) {
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	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);
}

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static char is_free(const direntry_t* direntry)
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{
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    return direntry->name[0]==0xe5 || direntry->name[0]==0x00;
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}

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static char is_volume_label(const direntry_t* direntry)
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{
    return direntry->attributes == 0x28;
}

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static char is_long_name(const direntry_t* direntry)
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{
    return direntry->attributes == 0xf;
}

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static char is_short_name(const direntry_t* direntry)
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{
    return !is_volume_label(direntry) && !is_long_name(direntry)
	&& !is_free(direntry);
}

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static char is_directory(const direntry_t* direntry)
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{
    return direntry->attributes & 0x10 && direntry->name[0] != 0xe5;
}

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static inline char is_dot(const direntry_t* direntry)
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{
    return is_short_name(direntry) && direntry->name[0] == '.';
}

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static char is_file(const direntry_t* direntry)
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{
    return is_short_name(direntry) && !is_directory(direntry);
}

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static inline uint32_t begin_of_direntry(const direntry_t* direntry)
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{
    return le16_to_cpu(direntry->begin)|(le16_to_cpu(direntry->begin_hi)<<16);
}

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static inline uint32_t filesize_of_direntry(const direntry_t* direntry)
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{
    return le32_to_cpu(direntry->size);
}

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static void set_begin_of_direntry(direntry_t* direntry, uint32_t begin)
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{
    direntry->begin = cpu_to_le16(begin & 0xffff);
    direntry->begin_hi = cpu_to_le16((begin >> 16) & 0xffff);
}

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/* fat functions */

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static inline uint8_t fat_chksum(const direntry_t* entry)
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{
    uint8_t chksum=0;
    int i;

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    for (i = 0; i < ARRAY_SIZE(entry->name); i++) {
        chksum = (((chksum & 0xfe) >> 1) |
                  ((chksum & 0x01) ? 0x80 : 0)) + entry->name[i];
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    }
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    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;
    struct tm t1;
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    t = &t1;
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    localtime_r(&time,t);
    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)
{
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    if(s->fat_type==32) {
	uint32_t* entry=array_get(&(s->fat),cluster);
	*entry=cpu_to_le32(value);
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    } else if(s->fat_type==16) {
	uint16_t* entry=array_get(&(s->fat),cluster);
	*entry=cpu_to_le16(value&0xffff);
    } else {
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	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;
	}
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    }
}

static inline uint32_t fat_get(BDRVVVFATState* s,unsigned int cluster)
{
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    if(s->fat_type==32) {
	uint32_t* entry=array_get(&(s->fat),cluster);
	return le32_to_cpu(*entry);
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    } else if(s->fat_type==16) {
	uint16_t* entry=array_get(&(s->fat),cluster);
	return le16_to_cpu(*entry);
    } else {
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	const uint8_t* x=(uint8_t*)(s->fat.pointer)+cluster*3/2;
573
	return ((x[0]|(x[1]<<8))>>(cluster&1?4:0))&0x0fff;
574 575 576 577 578 579 580 581 582 583 584 585
    }
}

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)
{
586 587 588 589 590 591 592 593 594
    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);
    }
595
    memset(s->fat.pointer,0,s->fat.size);
596

597 598 599
    switch(s->fat_type) {
	case 12: s->max_fat_value=0xfff; break;
	case 16: s->max_fat_value=0xffff; break;
600
	case 32: s->max_fat_value=0x0fffffff; break;
601 602 603 604 605
	default: s->max_fat_value=0; /* error... */
    }

}

606 607
/* TODO: in create_short_filename, 0xe5->0x05 is not yet handled! */
/* TODO: in parse_short_filename, 0x05->0xe5 is not yet handled! */
A
Anthony Liguori 已提交
608
static inline direntry_t* create_short_and_long_name(BDRVVVFATState* s,
609
	unsigned int directory_start, const char* filename, int is_dot)
610
{
611
    int i,j,long_index=s->directory.next;
A
Anthony Liguori 已提交
612 613
    direntry_t* entry = NULL;
    direntry_t* entry_long = NULL;
614 615 616

    if(is_dot) {
	entry=array_get_next(&(s->directory));
617
        memset(entry->name, 0x20, sizeof(entry->name));
618 619 620
	memcpy(entry->name,filename,strlen(filename));
	return entry;
    }
621

622
    entry_long=create_long_filename(s,filename);
623

624
    i = strlen(filename);
625 626 627 628 629 630
    for(j = i - 1; j>0  && filename[j]!='.';j--);
    if (j > 0)
	i = (j > 8 ? 8 : j);
    else if (i > 8)
	i = 8;

631
    entry=array_get_next(&(s->directory));
632
    memset(entry->name, 0x20, sizeof(entry->name));
B
blueswir1 已提交
633
    memcpy(entry->name, filename, i);
634

635 636 637 638 639
    if (j > 0) {
        for (i = 0; i < 3 && filename[j + 1 + i]; i++) {
            entry->name[8 + i] = filename[j + 1 + i];
        }
    }
640 641 642

    /* upcase & remove unwanted characters */
    for(i=10;i>=0;i--) {
643
	if(i==10 || i==7) for(;i>0 && entry->name[i]==' ';i--);
644
	if(entry->name[i]<=' ' || entry->name[i]>0x7f
645
		|| strchr(".*?<>|\":/\\[];,+='",entry->name[i]))
646 647 648 649 650 651 652
	    entry->name[i]='_';
        else if(entry->name[i]>='a' && entry->name[i]<='z')
            entry->name[i]+='A'-'a';
    }

    /* mangle duplicates */
    while(1) {
A
Anthony Liguori 已提交
653
	direntry_t* entry1=array_get(&(s->directory),directory_start);
654 655 656
	int j;

	for(;entry1<entry;entry1++)
657
	    if(!is_long_name(entry1) && !memcmp(entry1->name,entry->name,11))
658 659 660 661
		break; /* found dupe */
	if(entry1==entry) /* no dupe found */
	    break;

662
	/* use all 8 characters of name */
663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685
	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);
686
	while(entry_long<entry && is_long_name(entry_long)) {
687 688 689 690 691 692 693 694
	    entry_long->reserved[1]=chksum;
	    entry_long++;
	}
    }

    return entry;
}

695 696 697 698
/*
 * Read a directory. (the index of the corresponding mapping must be passed).
 */
static int read_directory(BDRVVVFATState* s, int mapping_index)
699
{
A
Anthony Liguori 已提交
700 701
    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
    direntry_t* direntry;
702 703 704
    const char* dirname = mapping->path;
    int first_cluster = mapping->begin;
    int parent_index = mapping->info.dir.parent_mapping_index;
A
Anthony Liguori 已提交
705
    mapping_t* parent_mapping = (mapping_t*)
706
        (parent_index >= 0 ? array_get(&(s->mapping), parent_index) : NULL);
707
    int first_cluster_of_parent = parent_mapping ? parent_mapping->begin : -1;
708 709 710 711 712

    DIR* dir=opendir(dirname);
    struct dirent* entry;
    int i;

713 714 715 716
    assert(mapping->mode & MODE_DIRECTORY);

    if(!dir) {
	mapping->end = mapping->begin;
717
	return -1;
718
    }
719

720 721 722
    i = mapping->info.dir.first_dir_index =
	    first_cluster == 0 ? 0 : s->directory.next;

723
    /* actually read the directory, and allocate the mappings */
724 725 726
    while((entry=readdir(dir))) {
	unsigned int length=strlen(dirname)+2+strlen(entry->d_name);
        char* buffer;
A
Anthony Liguori 已提交
727
	direntry_t* direntry;
728
        struct stat st;
729 730 731
	int is_dot=!strcmp(entry->d_name,".");
	int is_dotdot=!strcmp(entry->d_name,"..");

732
	if(first_cluster == 0 && (is_dotdot || is_dot))
733
	    continue;
734

735
	buffer = g_malloc(length);
736 737 738
	snprintf(buffer,length,"%s/%s",dirname,entry->d_name);

	if(stat(buffer,&st)<0) {
739
            g_free(buffer);
740 741 742 743
            continue;
	}

	/* create directory entry for this file */
744 745
	direntry=create_short_and_long_name(s, i, entry->d_name,
		is_dot || is_dotdot);
746 747 748 749 750 751 752 753 754
	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)
755
	    set_begin_of_direntry(direntry, first_cluster_of_parent);
756
	else if(is_dot)
757
	    set_begin_of_direntry(direntry, first_cluster);
758
	else
759 760 761
	    direntry->begin=0; /* do that later */
        if (st.st_size > 0x7fffffff) {
	    fprintf(stderr, "File %s is larger than 2GB\n", buffer);
762
            g_free(buffer);
B
Blue Swirl 已提交
763
            closedir(dir);
764 765 766
	    return -2;
        }
	direntry->size=cpu_to_le32(S_ISDIR(st.st_mode)?0:st.st_size);
767 768

	/* create mapping for this file */
769
	if(!is_dot && !is_dotdot && (S_ISDIR(st.st_mode) || st.st_size)) {
770
	    s->current_mapping = array_get_next(&(s->mapping));
771 772
	    s->current_mapping->begin=0;
	    s->current_mapping->end=st.st_size;
773 774 775 776
	    /*
	     * we get the direntry of the most recent direntry, which
	     * contains the short name and all the relevant information.
	     */
777
	    s->current_mapping->dir_index=s->directory.next-1;
778 779 780 781 782 783 784 785 786 787 788 789
	    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;
790 791 792
        } else {
            g_free(buffer);
        }
793 794 795 796 797
    }
    closedir(dir);

    /* fill with zeroes up to the end of the cluster */
    while(s->directory.next%(0x10*s->sectors_per_cluster)) {
A
Anthony Liguori 已提交
798 799
	direntry_t* direntry=array_get_next(&(s->directory));
	memset(direntry,0,sizeof(direntry_t));
800 801
    }

802 803 804 805 806 807
/* 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);
808
	s->directory.next = ROOT_ENTRIES;
809
	memset(array_get(&(s->directory), cur), 0,
A
Anthony Liguori 已提交
810
		(ROOT_ENTRIES - cur) * sizeof(direntry_t));
811
    }
812

813
     /* reget the mapping, since s->mapping was possibly realloc()ed */
814
    mapping = array_get(&(s->mapping), mapping_index);
815 816 817 818
    first_cluster += (s->directory.next - mapping->info.dir.first_dir_index)
	* 0x20 / s->cluster_size;
    mapping->end = first_cluster;

819
    direntry = array_get(&(s->directory), mapping->dir_index);
820
    set_begin_of_direntry(direntry, mapping->begin);
821

822 823
    return 0;
}
824

825 826 827 828
static inline uint32_t sector2cluster(BDRVVVFATState* s,off_t sector_num)
{
    return (sector_num-s->faked_sectors)/s->sectors_per_cluster;
}
829

830 831 832 833
static inline off_t cluster2sector(BDRVVVFATState* s, uint32_t cluster_num)
{
    return s->faked_sectors + s->sectors_per_cluster * cluster_num;
}
834

835
static int init_directories(BDRVVVFATState* s,
836 837
                            const char *dirname, int heads, int secs,
                            Error **errp)
838
{
A
Anthony Liguori 已提交
839 840
    bootsector_t* bootsector;
    mapping_t* mapping;
841 842 843 844 845 846
    unsigned int i;
    unsigned int cluster;

    memset(&(s->first_sectors[0]),0,0x40*0x200);

    s->cluster_size=s->sectors_per_cluster*0x200;
847
    s->cluster_buffer=g_malloc(s->cluster_size);
848 849 850 851 852 853 854 855 856 857

    /*
     * 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 */
858

A
Anthony Liguori 已提交
859 860
    array_init(&(s->mapping),sizeof(mapping_t));
    array_init(&(s->directory),sizeof(direntry_t));
861 862 863

    /* add volume label */
    {
A
Anthony Liguori 已提交
864
	direntry_t* entry=array_get_next(&(s->directory));
865
	entry->attributes=0x28; /* archive | volume label */
W
Wolfgang Bumiller 已提交
866
        memcpy(entry->name, s->volume_label, sizeof(entry->name));
867 868 869 870 871
    }

    /* Now build FAT, and write back information into directory */
    init_fat(s);

872 873 874 875 876 877 878 879
    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;
880
    mapping->path = g_strdup(dirname);
881 882 883 884 885 886 887 888
    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++) {
889
	/* MS-DOS expects the FAT to be 0 for the root directory
890 891 892 893 894 895 896 897
	 * (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)) {
898 899
                error_setg(errp, "Could not read directory %s",
                           mapping->path);
900 901
		return -1;
	    }
902 903 904
	    mapping = array_get(&(s->mapping), i);
	} else {
	    assert(mapping->mode == MODE_UNDEFINED);
905
	    mapping->mode=MODE_NORMAL;
906 907
	    mapping->begin = cluster;
	    if (mapping->end > 0) {
A
Anthony Liguori 已提交
908
		direntry_t* direntry = array_get(&(s->directory),
909 910 911 912 913 914 915
			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;
916
	    }
917 918 919 920
	}

	assert(mapping->begin < mapping->end);

921 922 923 924
	/* next free cluster */
	cluster = mapping->end;

	if(cluster > s->cluster_count) {
925 926 927 928
            error_setg(errp,
                       "Directory does not fit in FAT%d (capacity %.2f MB)",
                       s->fat_type, s->sector_count / 2000.0);
            return -1;
929 930
	}

931 932
	/* fix fat for entry */
	if (fix_fat) {
933
	    int j;
934 935 936 937
	    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);
	}
938 939
    }

940 941 942 943 944 945 946
    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);
947

948 949
    s->current_mapping = NULL;

A
Anthony Liguori 已提交
950
    bootsector=(bootsector_t*)(s->first_sectors+(s->first_sectors_number-1)*0x200);
951 952 953 954 955 956 957 958 959
    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);
960
    bootsector->total_sectors16=s->sector_count>0xffff?0:cpu_to_le16(s->sector_count);
961
    bootsector->media_type=(s->first_sectors_number>1?0xf8:0xf0); /* media descriptor (f8=hd, f0=3.5 fd)*/
962
    s->fat.pointer[0] = bootsector->media_type;
963
    bootsector->sectors_per_fat=cpu_to_le16(s->sectors_per_fat);
964 965
    bootsector->sectors_per_track = cpu_to_le16(secs);
    bootsector->number_of_heads = cpu_to_le16(heads);
966
    bootsector->hidden_sectors=cpu_to_le32(s->first_sectors_number==1?0:0x3f);
967
    bootsector->total_sectors=cpu_to_le32(s->sector_count>0xffff?s->sector_count:0);
968

969
    /* LATER TODO: if FAT32, this is wrong */
970
    bootsector->u.fat16.drive_number=s->first_sectors_number==1?0:0x80; /* fda=0, hda=0x80 */
971 972 973 974
    bootsector->u.fat16.current_head=0;
    bootsector->u.fat16.signature=0x29;
    bootsector->u.fat16.id=cpu_to_le32(0xfabe1afd);

W
Wolfgang Bumiller 已提交
975 976
    memcpy(bootsector->u.fat16.volume_label, s->volume_label,
           sizeof(bootsector->u.fat16.volume_label));
977 978 979 980 981 982
    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;
}

B
bellard 已提交
983
#ifdef DEBUG
984
static BDRVVVFATState *vvv = NULL;
B
bellard 已提交
985
#endif
986

987
static int enable_write_target(BDRVVVFATState *s, Error **errp);
988 989
static int is_consistent(BDRVVVFATState *s);

990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008
static QemuOptsList runtime_opts = {
    .name = "vvfat",
    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
    .desc = {
        {
            .name = "dir",
            .type = QEMU_OPT_STRING,
            .help = "Host directory to map to the vvfat device",
        },
        {
            .name = "fat-type",
            .type = QEMU_OPT_NUMBER,
            .help = "FAT type (12, 16 or 32)",
        },
        {
            .name = "floppy",
            .type = QEMU_OPT_BOOL,
            .help = "Create a floppy rather than a hard disk image",
        },
W
Wolfgang Bumiller 已提交
1009 1010 1011 1012 1013
        {
            .name = "label",
            .type = QEMU_OPT_STRING,
            .help = "Use a volume label other than QEMU VVFAT",
        },
1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
        {
            .name = "rw",
            .type = QEMU_OPT_BOOL,
            .help = "Make the image writable",
        },
        { /* end of list */ }
    },
};

static void vvfat_parse_filename(const char *filename, QDict *options,
                                 Error **errp)
{
    int fat_type = 0;
    bool floppy = false;
    bool rw = false;
    int i;

    if (!strstart(filename, "fat:", NULL)) {
        error_setg(errp, "File name string must start with 'fat:'");
        return;
    }

    /* Parse options */
    if (strstr(filename, ":32:")) {
        fat_type = 32;
    } else if (strstr(filename, ":16:")) {
        fat_type = 16;
    } else if (strstr(filename, ":12:")) {
        fat_type = 12;
    }

    if (strstr(filename, ":floppy:")) {
        floppy = true;
    }

    if (strstr(filename, ":rw:")) {
        rw = true;
    }

    /* Get the directory name without options */
    i = strrchr(filename, ':') - filename;
    assert(i >= 3);
    if (filename[i - 2] == ':' && qemu_isalpha(filename[i - 1])) {
        /* workaround for DOS drive names */
        filename += i - 1;
    } else {
        filename += i + 1;
    }

    /* Fill in the options QDict */
    qdict_put(options, "dir", qstring_from_str(filename));
    qdict_put(options, "fat-type", qint_from_int(fat_type));
E
Eric Blake 已提交
1066 1067
    qdict_put(options, "floppy", qbool_from_bool(floppy));
    qdict_put(options, "rw", qbool_from_bool(rw));
1068 1069
}

M
Max Reitz 已提交
1070 1071
static int vvfat_open(BlockDriverState *bs, QDict *options, int flags,
                      Error **errp)
1072 1073
{
    BDRVVVFATState *s = bs->opaque;
1074 1075
    int cyls, heads, secs;
    bool floppy;
W
Wolfgang Bumiller 已提交
1076
    const char *dirname, *label;
1077 1078 1079
    QemuOpts *opts;
    Error *local_err = NULL;
    int ret;
1080

B
bellard 已提交
1081
#ifdef DEBUG
1082
    vvv = s;
B
bellard 已提交
1083
#endif
1084

1085
    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
1086
    qemu_opts_absorb_qdict(opts, options, &local_err);
1087
    if (local_err) {
1088
        error_propagate(errp, local_err);
1089 1090 1091 1092 1093 1094
        ret = -EINVAL;
        goto fail;
    }

    dirname = qemu_opt_get(opts, "dir");
    if (!dirname) {
1095
        error_setg(errp, "vvfat block driver requires a 'dir' option");
1096 1097 1098 1099 1100 1101 1102
        ret = -EINVAL;
        goto fail;
    }

    s->fat_type = qemu_opt_get_number(opts, "fat-type", 0);
    floppy = qemu_opt_get_bool(opts, "floppy", false);

W
Wolfgang Bumiller 已提交
1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
    memset(s->volume_label, ' ', sizeof(s->volume_label));
    label = qemu_opt_get(opts, "label");
    if (label) {
        size_t label_length = strlen(label);
        if (label_length > 11) {
            error_setg(errp, "vvfat label cannot be longer than 11 bytes");
            ret = -EINVAL;
            goto fail;
        }
        memcpy(s->volume_label, label, label_length);
K
Kevin Wolf 已提交
1113 1114
    } else {
        memcpy(s->volume_label, "QEMU VVFAT", 10);
W
Wolfgang Bumiller 已提交
1115 1116
    }

1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134
    if (floppy) {
        /* 1.44MB or 2.88MB floppy.  2.88MB can be FAT12 (default) or FAT16. */
        if (!s->fat_type) {
            s->fat_type = 12;
            secs = 36;
            s->sectors_per_cluster = 2;
        } else {
            secs = s->fat_type == 12 ? 18 : 36;
            s->sectors_per_cluster = 1;
        }
        s->first_sectors_number = 1;
        cyls = 80;
        heads = 2;
    } else {
        /* 32MB or 504MB disk*/
        if (!s->fat_type) {
            s->fat_type = 16;
        }
1135
        s->first_sectors_number = 0x40;
1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149
        cyls = s->fat_type == 12 ? 64 : 1024;
        heads = 16;
        secs = 63;
    }

    switch (s->fat_type) {
    case 32:
	    fprintf(stderr, "Big fat greek warning: FAT32 has not been tested. "
                "You are welcome to do so!\n");
        break;
    case 16:
    case 12:
        break;
    default:
1150
        error_setg(errp, "Valid FAT types are only 12, 16 and 32");
1151 1152 1153 1154 1155
        ret = -EINVAL;
        goto fail;
    }


1156 1157 1158 1159
    s->bs = bs;

    /* LATER TODO: if FAT32, adjust */
    s->sectors_per_cluster=0x10;
1160 1161 1162

    s->current_cluster=0xffffffff;

1163 1164 1165 1166 1167 1168
    /* 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;
1169

1170 1171
    fprintf(stderr, "vvfat %s chs %d,%d,%d\n",
            dirname, cyls, heads, secs);
1172

1173
    s->sector_count = cyls * heads * secs - (s->first_sectors_number - 1);
1174

1175
    if (qemu_opt_get_bool(opts, "rw", false)) {
1176
        ret = enable_write_target(s, errp);
1177
        if (ret < 0) {
1178 1179 1180
            goto fail;
        }
        bs->read_only = 0;
T
ths 已提交
1181 1182
    }

1183
    bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */
1184
    bs->total_sectors = cyls * heads * secs;
T
ths 已提交
1185

1186
    if (init_directories(s, dirname, heads, secs, errp)) {
1187 1188
        ret = -EIO;
        goto fail;
1189
    }
1190

T
ths 已提交
1191 1192
    s->sector_count = s->faked_sectors + s->sectors_per_cluster*s->cluster_count;

1193 1194
    if (s->first_sectors_number == 0x40) {
        init_mbr(s, cyls, heads, secs);
1195
    }
1196 1197

    //    assert(is_consistent(s));
1198
    qemu_co_mutex_init(&s->lock);
K
Kevin Wolf 已提交
1199 1200 1201

    /* Disable migration when vvfat is used rw */
    if (s->qcow) {
1202 1203 1204 1205
        error_setg(&s->migration_blocker,
                   "The vvfat (rw) format used by node '%s' "
                   "does not support live migration",
                   bdrv_get_device_or_node_name(bs));
K
Kevin Wolf 已提交
1206 1207 1208
        migrate_add_blocker(s->migration_blocker);
    }

1209 1210 1211 1212
    ret = 0;
fail:
    qemu_opts_del(opts);
    return ret;
1213 1214 1215 1216 1217
}

static inline void vvfat_close_current_file(BDRVVVFATState *s)
{
    if(s->current_mapping) {
1218 1219
	s->current_mapping = NULL;
	if (s->current_fd) {
1220
		qemu_close(s->current_fd);
1221 1222
		s->current_fd = 0;
	}
1223
    }
1224
    s->current_cluster = -1;
1225 1226 1227 1228 1229 1230 1231 1232
}

/* 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)
{
    while(1) {
1233
        int index3;
A
Anthony Liguori 已提交
1234
	mapping_t* mapping;
1235 1236
	index3=(index1+index2)/2;
	mapping=array_get(&(s->mapping),index3);
1237 1238
	assert(mapping->begin < mapping->end);
	if(mapping->begin>=cluster_num) {
1239 1240
	    assert(index2!=index3 || index2==0);
	    if(index2==index3)
1241
		return index1;
1242 1243 1244
	    index2=index3;
	} else {
	    if(index1==index3)
1245
		return mapping->end<=cluster_num ? index2 : index1;
1246 1247 1248
	    index1=index3;
	}
	assert(index1<=index2);
1249 1250
	DLOG(mapping=array_get(&(s->mapping),index1);
	assert(mapping->begin<=cluster_num);
1251
	assert(index2 >= s->mapping.next ||
1252 1253
		((mapping = array_get(&(s->mapping),index2)) &&
		mapping->end>cluster_num)));
1254 1255 1256
    }
}

A
Anthony Liguori 已提交
1257
static inline mapping_t* find_mapping_for_cluster(BDRVVVFATState* s,int cluster_num)
1258 1259
{
    int index=find_mapping_for_cluster_aux(s,cluster_num,0,s->mapping.next);
A
Anthony Liguori 已提交
1260
    mapping_t* mapping;
1261
    if(index>=s->mapping.next)
1262
        return NULL;
1263 1264
    mapping=array_get(&(s->mapping),index);
    if(mapping->begin>cluster_num)
1265
        return NULL;
1266
    assert(mapping->begin<=cluster_num && mapping->end>cluster_num);
1267 1268 1269
    return mapping;
}

A
Anthony Liguori 已提交
1270
static int open_file(BDRVVVFATState* s,mapping_t* mapping)
1271 1272 1273 1274
{
    if(!mapping)
	return -1;
    if(!s->current_mapping ||
1275
	    strcmp(s->current_mapping->path,mapping->path)) {
1276
	/* open file */
1277
	int fd = qemu_open(mapping->path, O_RDONLY | O_BINARY | O_LARGEFILE);
1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291
	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;
1292
	assert(!s->current_mapping || s->current_fd || (s->current_mapping->mode & MODE_DIRECTORY));
1293 1294 1295 1296
	if(!s->current_mapping
		|| s->current_mapping->begin>cluster_num
		|| s->current_mapping->end<=cluster_num) {
	    /* binary search of mappings for file */
A
Anthony Liguori 已提交
1297
	    mapping_t* mapping=find_mapping_for_cluster(s,cluster_num);
1298 1299 1300 1301 1302 1303 1304 1305

	    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);
T
ths 已提交
1306
		s->cluster = (unsigned char*)s->directory.pointer+offset
1307 1308 1309 1310 1311 1312 1313 1314
			+ 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))
1315
		return -2;
1316 1317
	} else if (s->current_mapping->mode & MODE_DIRECTORY)
	    goto read_cluster_directory;
1318

1319 1320 1321
	assert(s->current_fd);

	offset=s->cluster_size*(cluster_num-s->current_mapping->begin)+s->current_mapping->info.file.offset;
1322 1323
	if(lseek(s->current_fd, offset, SEEK_SET)!=offset)
	    return -3;
1324
	s->cluster=s->cluster_buffer;
1325 1326 1327 1328 1329 1330 1331 1332 1333 1334
	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;
}

1335
#ifdef DEBUG
A
Anthony Liguori 已提交
1336
static void print_direntry(const direntry_t* direntry)
1337
{
1338 1339 1340
    int j = 0;
    char buffer[1024];

K
Kevin Wolf 已提交
1341
    fprintf(stderr, "direntry %p: ", direntry);
1342 1343
    if(!direntry)
	return;
1344
    if(is_long_name(direntry)) {
1345 1346 1347
	unsigned char* c=(unsigned char*)direntry;
	int i;
	for(i=1;i<11 && c[i] && c[i]!=0xff;i+=2)
1348
#define ADD_CHAR(c) {buffer[j] = (c); if (buffer[j] < ' ') buffer[j] = 0xb0; j++;}
1349
	    ADD_CHAR(c[i]);
1350
	for(i=14;i<26 && c[i] && c[i]!=0xff;i+=2)
1351
	    ADD_CHAR(c[i]);
1352
	for(i=28;i<32 && c[i] && c[i]!=0xff;i+=2)
1353 1354 1355
	    ADD_CHAR(c[i]);
	buffer[j] = 0;
	fprintf(stderr, "%s\n", buffer);
1356 1357 1358
    } else {
	int i;
	for(i=0;i<11;i++)
1359 1360 1361 1362
	    ADD_CHAR(direntry->name[i]);
	buffer[j] = 0;
	fprintf(stderr,"%s attributes=0x%02x begin=%d size=%d\n",
		buffer,
1363
		direntry->attributes,
1364
		begin_of_direntry(direntry),le32_to_cpu(direntry->size));
1365 1366 1367
    }
}

A
Anthony Liguori 已提交
1368
static void print_mapping(const mapping_t* mapping)
1369
{
K
Kevin Wolf 已提交
1370 1371 1372 1373 1374
    fprintf(stderr, "mapping (%p): begin, end = %d, %d, dir_index = %d, "
        "first_mapping_index = %d, name = %s, mode = 0x%x, " ,
        mapping, mapping->begin, mapping->end, mapping->dir_index,
        mapping->first_mapping_index, mapping->path, mapping->mode);

1375 1376 1377 1378
    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);
1379
}
1380
#endif
1381

1382
static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
1383
                    uint8_t *buf, int nb_sectors)
1384
{
1385
    BDRVVVFATState *s = bs->opaque;
1386 1387
    int i;

1388
    for(i=0;i<nb_sectors;i++,sector_num++) {
1389
	if (sector_num >= bs->total_sectors)
1390 1391 1392
	   return -1;
	if (s->qcow) {
	    int n;
K
Kevin Wolf 已提交
1393
            if (bdrv_is_allocated(s->qcow, sector_num, nb_sectors-i, &n)) {
1394
DLOG(fprintf(stderr, "sectors %d+%d allocated\n", (int)sector_num, n));
K
Kevin Wolf 已提交
1395 1396 1397 1398 1399 1400 1401
                if (bdrv_read(s->qcow, sector_num, buf + i*0x200, n)) {
                    return -1;
                }
                i += n - 1;
                sector_num += n - 1;
                continue;
            }
1402
DLOG(fprintf(stderr, "sector %d not allocated\n", (int)sector_num));
1403
	}
1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414
	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;
1415
	    if(cluster_num > s->cluster_count || read_cluster(s, cluster_num) != 0) {
1416 1417 1418
		/* LATER TODO: strict: return -1; */
		memset(buf+i*0x200,0,0x200);
		continue;
1419
	    }
1420
	    memcpy(buf+i*0x200,s->cluster+sector_offset_in_cluster*0x200,0x200);
1421 1422 1423 1424 1425
	}
    }
    return 0;
}

1426 1427 1428
static int coroutine_fn
vvfat_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                QEMUIOVector *qiov, int flags)
1429 1430 1431
{
    int ret;
    BDRVVVFATState *s = bs->opaque;
1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443
    uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
    int nb_sectors = bytes >> BDRV_SECTOR_BITS;
    void *buf;

    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);

    buf = g_try_malloc(bytes);
    if (bytes && buf == NULL) {
        return -ENOMEM;
    }

1444 1445 1446
    qemu_co_mutex_lock(&s->lock);
    ret = vvfat_read(bs, sector_num, buf, nb_sectors);
    qemu_co_mutex_unlock(&s->lock);
1447 1448 1449 1450

    qemu_iovec_from_buf(qiov, 0, buf, bytes);
    g_free(buf);

1451 1452 1453
    return ret;
}

1454
/* LATER TODO: statify all functions */
1455

1456 1457
/*
 * Idea of the write support (use snapshot):
1458
 *
1459 1460
 * 1. check if all data is consistent, recording renames, modifications,
 *    new files and directories (in s->commits).
1461
 *
1462
 * 2. if the data is not consistent, stop committing
1463
 *
1464 1465
 * 3. handle renames, and create new files and directories (do not yet
 *    write their contents)
1466
 *
1467 1468
 * 4. walk the directories, fixing the mapping and direntries, and marking
 *    the handled mappings as not deleted
1469
 *
1470
 * 5. commit the contents of the files
1471
 *
1472
 * 6. handle deleted files and directories
1473 1474 1475
 *
 */

A
Anthony Liguori 已提交
1476
typedef struct commit_t {
1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487
    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;
A
Anthony Liguori 已提交
1488
} commit_t;
1489

1490
static void clear_commits(BDRVVVFATState* s)
1491 1492
{
    int i;
1493 1494
DLOG(fprintf(stderr, "clear_commits (%d commits)\n", s->commits.next));
    for (i = 0; i < s->commits.next; i++) {
A
Anthony Liguori 已提交
1495
	commit_t* commit = array_get(&(s->commits), i);
1496 1497 1498
	assert(commit->path || commit->action == ACTION_WRITEOUT);
	if (commit->action != ACTION_WRITEOUT) {
	    assert(commit->path);
1499
            g_free(commit->path);
1500 1501
	} else
	    assert(commit->path == NULL);
1502
    }
1503
    s->commits.next = 0;
1504 1505
}

1506 1507
static void schedule_rename(BDRVVVFATState* s,
	uint32_t cluster, char* new_path)
1508
{
A
Anthony Liguori 已提交
1509
    commit_t* commit = array_get_next(&(s->commits));
1510 1511 1512
    commit->path = new_path;
    commit->param.rename.cluster = cluster;
    commit->action = ACTION_RENAME;
1513 1514
}

1515 1516
static void schedule_writeout(BDRVVVFATState* s,
	int dir_index, uint32_t modified_offset)
1517
{
A
Anthony Liguori 已提交
1518
    commit_t* commit = array_get_next(&(s->commits));
1519 1520 1521 1522
    commit->path = NULL;
    commit->param.writeout.dir_index = dir_index;
    commit->param.writeout.modified_offset = modified_offset;
    commit->action = ACTION_WRITEOUT;
1523 1524
}

1525 1526
static void schedule_new_file(BDRVVVFATState* s,
	char* path, uint32_t first_cluster)
1527
{
A
Anthony Liguori 已提交
1528
    commit_t* commit = array_get_next(&(s->commits));
1529 1530 1531 1532 1533 1534 1535
    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)
{
A
Anthony Liguori 已提交
1536
    commit_t* commit = array_get_next(&(s->commits));
1537 1538 1539 1540 1541 1542
    commit->path = path;
    commit->param.mkdir.cluster = cluster;
    commit->action = ACTION_MKDIR;
}

typedef struct {
1543 1544 1545 1546 1547 1548
    /*
     * 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];
1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560
    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,
A
Anthony Liguori 已提交
1561
	const direntry_t* direntry)
1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572
{
    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;
T
ths 已提交
1573
	lfn->name[lfn->sequence_number * 13] = 0;
1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593
    } 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;
1594
    }
1595 1596

    if (pointer[0] & 0x40)
T
ths 已提交
1597
	lfn->len = offset + strlen((char*)lfn->name + offset);
1598

1599 1600 1601
    return 0;
}

1602 1603
/* returns 0 if successful, >0 if no short_name, and <0 on error */
static int parse_short_name(BDRVVVFATState* s,
A
Anthony Liguori 已提交
1604
	long_file_name* lfn, direntry_t* direntry)
1605
{
1606
    int i, j;
1607

1608 1609 1610 1611 1612 1613 1614 1615
    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)
1616
	    lfn->name[i] = qemu_tolower(direntry->name[i]);
1617 1618
	else
	    lfn->name[i] = direntry->name[i];
1619 1620
    }

1621 1622
    for (j = 2; j >= 0 && direntry->name[8 + j] == ' '; j--) {
    }
1623 1624 1625 1626
    if (j >= 0) {
	lfn->name[i++] = '.';
	lfn->name[i + j + 1] = '\0';
	for (;j >= 0; j--) {
1627 1628 1629 1630 1631 1632 1633 1634
            uint8_t c = direntry->name[8 + j];
            if (c <= ' ' || c > 0x7f) {
                return -2;
            } else if (s->downcase_short_names) {
                lfn->name[i + j] = qemu_tolower(c);
            } else {
                lfn->name[i + j] = c;
            }
1635 1636 1637 1638
	}
    } else
	lfn->name[i + j + 1] = '\0';

T
ths 已提交
1639
    lfn->len = strlen((char*)lfn->name);
1640 1641

    return 0;
1642 1643
}

1644 1645
static inline uint32_t modified_fat_get(BDRVVVFATState* s,
	unsigned int cluster)
1646
{
1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671
    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)
1672
	return 0;
1673 1674

    for (i = 0; !was_modified && i < s->sectors_per_cluster; i++)
K
Kevin Wolf 已提交
1675
	was_modified = bdrv_is_allocated(s->qcow,
1676 1677 1678
		cluster2sector(s, cluster_num) + i, 1, &dummy);

    return was_modified;
1679 1680
}

1681
static const char* get_basename(const char* path)
1682
{
1683 1684 1685 1686 1687
    char* basename = strrchr(path, '/');
    if (basename == NULL)
	return path;
    else
	return basename + 1; /* strip '/' */
1688 1689
}

1690 1691 1692 1693 1694 1695 1696 1697 1698
/*
 * 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
A
Anthony Liguori 已提交
1699
} used_t;
1700

1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711
/*
 * 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,
A
Anthony Liguori 已提交
1712
	direntry_t* direntry, const char* path)
1713
{
1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737
    /*
     * 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;
A
Anthony Liguori 已提交
1738
    mapping_t* mapping = NULL;
1739
    const char* basename2 = NULL;
1740

1741
    vvfat_close_current_file(s);
1742

1743 1744
    /* the root directory */
    if (cluster_num == 0)
1745 1746
	return 0;

1747 1748 1749
    /* write support */
    if (s->qcow) {
	basename2 = get_basename(path);
1750

1751 1752 1753
	mapping = find_mapping_for_cluster(s, cluster_num);

	if (mapping) {
B
bellard 已提交
1754 1755
	    const char* basename;

1756 1757 1758
	    assert(mapping->mode & MODE_DELETED);
	    mapping->mode &= ~MODE_DELETED;

B
bellard 已提交
1759
	    basename = get_basename(mapping->path);
1760 1761 1762 1763 1764

	    assert(mapping->mode & MODE_NORMAL);

	    /* rename */
	    if (strcmp(basename, basename2))
1765
		schedule_rename(s, cluster_num, g_strdup(path));
1766 1767
	} else if (is_file(direntry))
	    /* new file */
1768
	    schedule_new_file(s, g_strdup(path), cluster_num);
1769
	else {
1770
            abort();
1771 1772
	    return 0;
	}
1773 1774
    }

1775 1776 1777 1778 1779 1780 1781
    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);
1782

1783 1784 1785 1786 1787 1788 1789 1790

		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 */
1791
                        abort();
1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802
			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) {
1803
                        abort();
1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823
			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);
K
Kevin Wolf 已提交
1824 1825 1826 1827 1828 1829 1830 1831 1832 1833
                for (i = 0; i < s->sectors_per_cluster; i++) {
                    if (!bdrv_is_allocated(s->qcow, offset + i, 1, &dummy)) {
                        if (vvfat_read(s->bs, offset, s->cluster_buffer, 1)) {
                            return -1;
                        }
                        if (bdrv_write(s->qcow, offset, s->cluster_buffer, 1)) {
                            return -2;
                        }
                    }
                }
1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850
	    }
	}

	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;
    }
1851 1852
}

1853
/*
1854
 * This function looks at the modified data (qcow).
1855 1856 1857 1858 1859
 * 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)
1860
{
1861
    int ret = 0;
1862
    unsigned char* cluster = g_malloc(s->cluster_size);
A
Anthony Liguori 已提交
1863 1864
    direntry_t* direntries = (direntry_t*)cluster;
    mapping_t* mapping = find_mapping_for_cluster(s, cluster_num);
1865 1866 1867

    long_file_name lfn;
    int path_len = strlen(path);
K
Kevin Wolf 已提交
1868
    char path2[PATH_MAX + 1];
1869 1870

    assert(path_len < PATH_MAX); /* len was tested before! */
B
blueswir1 已提交
1871
    pstrcpy(path2, sizeof(path2), path);
1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884
    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))
1885
	    schedule_rename(s, cluster_num, g_strdup(path));
1886 1887
    } else
	/* new directory */
1888
	schedule_mkdir(s, cluster_num, g_strdup(path));
1889

1890 1891
    lfn_init(&lfn);
    do {
1892
	int i;
1893 1894 1895 1896 1897 1898
	int subret = 0;

	ret++;

	if (s->used_clusters[cluster_num] & USED_ANY) {
	    fprintf(stderr, "cluster %d used more than once\n", (int)cluster_num);
1899
            goto fail;
1900 1901 1902 1903 1904 1905 1906 1907 1908
	}
	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:
1909
            g_free(cluster);
1910 1911 1912 1913
	    return 0;
	}

	for (i = 0; i < 0x10 * s->sectors_per_cluster; i++) {
1914
	    int cluster_count = 0;
1915

1916
DLOG(fprintf(stderr, "check direntry %d:\n", i); print_direntry(direntries + i));
1917 1918 1919 1920 1921 1922 1923 1924
	    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;
1925
	    }
1926 1927 1928 1929 1930 1931 1932 1933 1934
	    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;
		}
T
ths 已提交
1935 1936
		if (subret > 0 || !strcmp((char*)lfn.name, ".")
			|| !strcmp((char*)lfn.name, ".."))
1937 1938 1939 1940 1941 1942 1943 1944
		    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;
	    }
B
blueswir1 已提交
1945 1946
            pstrcpy(path2 + path_len + 1, sizeof(path2) - path_len - 1,
                    (char*)lfn.name);
1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962

	    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 !=
L
Laurent Vivier 已提交
1963
            DIV_ROUND_UP(le32_to_cpu(direntries[i].size), s->cluster_size)) {
1964 1965 1966 1967
		    DLOG(fprintf(stderr, "Cluster count mismatch\n"));
		    goto fail;
		}
	    } else
1968
                abort(); /* cluster_count = 0; */
1969 1970

	    ret += cluster_count;
1971 1972
	}

1973 1974
	cluster_num = modified_fat_get(s, cluster_num);
    } while(!fat_eof(s, cluster_num));
1975

1976
    g_free(cluster);
1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
    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;
2002
	s->fat2 = g_malloc(size);
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
	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++) {
A
Anthony Liguori 已提交
2021
	    mapping_t* mapping = array_get(&(s->mapping), i);
2022 2023
	    if (mapping->first_mapping_index < 0)
		mapping->mode |= MODE_DELETED;
2024
	}
2025 2026 2027 2028 2029

    used_clusters_count = check_directory_consistency(s, 0, s->path);
    if (used_clusters_count <= 0) {
	DLOG(fprintf(stderr, "problem in directory\n"));
	return 0;
2030 2031
    }

2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060
    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++) {
A
Anthony Liguori 已提交
2061
	mapping_t* mapping = array_get(&(s->mapping), i);
2062 2063 2064 2065 2066 2067 2068 2069

#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);
2070
    }
2071 2072 2073
}

/* insert or update mapping */
A
Anthony Liguori 已提交
2074
static mapping_t* insert_mapping(BDRVVVFATState* s,
2075 2076 2077 2078 2079 2080 2081 2082 2083 2084
	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);
A
Anthony Liguori 已提交
2085 2086
    mapping_t* mapping = NULL;
    mapping_t* first_mapping = array_get(&(s->mapping), 0);
2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101

    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;
2102

A
Anthony Liguori 已提交
2103
DLOG(mapping_t* next_mapping;
2104 2105 2106 2107
assert(index + 1 >= s->mapping.next ||
((next_mapping = array_get(&(s->mapping), index + 1)) &&
 next_mapping->begin >= end)));

A
Anthony Liguori 已提交
2108
    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
2109 2110 2111 2112 2113 2114 2115 2116
	s->current_mapping = array_get(&(s->mapping),
		s->current_mapping - first_mapping);

    return mapping;
}

static int remove_mapping(BDRVVVFATState* s, int mapping_index)
{
A
Anthony Liguori 已提交
2117 2118
    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
    mapping_t* first_mapping = array_get(&(s->mapping), 0);
2119 2120

    /* free mapping */
2121 2122 2123
    if (mapping->first_mapping_index < 0) {
        g_free(mapping->path);
    }
2124 2125 2126 2127 2128 2129 2130

    /* remove from s->mapping */
    array_remove(&(s->mapping), mapping_index);

    /* adjust all references to mappings */
    adjust_mapping_indices(s, mapping_index, -1);

A
Anthony Liguori 已提交
2131
    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
2132 2133
	s->current_mapping = array_get(&(s->mapping),
		s->current_mapping - first_mapping);
2134 2135 2136 2137

    return 0;
}

2138 2139 2140 2141
static void adjust_dirindices(BDRVVVFATState* s, int offset, int adjust)
{
    int i;
    for (i = 0; i < s->mapping.next; i++) {
A
Anthony Liguori 已提交
2142
	mapping_t* mapping = array_get(&(s->mapping), i);
2143 2144 2145 2146 2147 2148 2149
	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;
    }
}
2150

A
Anthony Liguori 已提交
2151
static direntry_t* insert_direntries(BDRVVVFATState* s,
2152
	int dir_index, int count)
2153
{
2154 2155 2156 2157
    /*
     * make room in s->directory,
     * adjust_dirindices
     */
A
Anthony Liguori 已提交
2158
    direntry_t* result = array_insert(&(s->directory), dir_index, count);
2159 2160 2161
    if (result == NULL)
	return NULL;
    adjust_dirindices(s, dir_index, count);
2162 2163 2164
    return result;
}

2165 2166 2167 2168 2169 2170 2171 2172
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;
}
2173

2174 2175 2176 2177 2178 2179 2180 2181
/*
 * 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)
2182
{
A
Anthony Liguori 已提交
2183 2184
    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215
    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);
A
Anthony Liguori 已提交
2216
	    mapping_t* next_mapping = i >= s->mapping.next ? NULL :
2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229
		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;
2230
	    next_mapping->first_mapping_index =
2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249
		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;
	}
2250

2251 2252
	cluster = c1;
    }
2253 2254 2255 2256

    return 0;
}

2257 2258
static int commit_direntries(BDRVVVFATState* s,
	int dir_index, int parent_mapping_index)
2259
{
A
Anthony Liguori 已提交
2260
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2261
    uint32_t first_cluster = dir_index == 0 ? 0 : begin_of_direntry(direntry);
A
Anthony Liguori 已提交
2262
    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288

    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++;
2289

2290 2291 2292 2293
	for (new_cluster_count = 0, c = first_cluster; !fat_eof(s, c);
		c = modified_fat_get(s, c))
	    new_cluster_count++;
    }
2294

2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305
    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)) {
K
Kevin Wolf 已提交
2306
        direntry_t *first_direntry;
2307 2308 2309 2310 2311
	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;
K
Kevin Wolf 已提交
2312 2313 2314 2315 2316

        /* The first directory entry on the filesystem is the volume name */
        first_direntry = (direntry_t*) s->directory.pointer;
        assert(!memcmp(first_direntry->name, s->volume_label, 11));

2317 2318
	current_dir_index += factor;
    }
2319

2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335
    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;
	}
    }
2336

2337 2338
    return 0;
}
2339

2340 2341 2342 2343 2344
/* commit one file (adjust contents, adjust mapping),
   return first_mapping_index */
static int commit_one_file(BDRVVVFATState* s,
	int dir_index, uint32_t offset)
{
A
Anthony Liguori 已提交
2345
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2346 2347
    uint32_t c = begin_of_direntry(direntry);
    uint32_t first_cluster = c;
A
Anthony Liguori 已提交
2348
    mapping_t* mapping = find_mapping_for_cluster(s, c);
2349
    uint32_t size = filesize_of_direntry(direntry);
2350
    char* cluster = g_malloc(s->cluster_size);
2351 2352 2353 2354 2355 2356 2357 2358 2359
    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);

2360
    fd = qemu_open(mapping->path, O_RDWR | O_CREAT | O_BINARY, 0666);
2361 2362 2363
    if (fd < 0) {
	fprintf(stderr, "Could not open %s... (%s, %d)\n", mapping->path,
		strerror(errno), errno);
2364
        g_free(cluster);
2365
	return fd;
2366
    }
2367 2368
    if (offset > 0) {
        if (lseek(fd, offset, SEEK_SET) != offset) {
2369
            qemu_close(fd);
2370 2371 2372 2373
            g_free(cluster);
            return -3;
        }
    }
2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386

    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),
T
ths 已提交
2387
	    (uint8_t*)cluster, (rest_size + 0x1ff) / 0x200);
2388

2389
        if (ret < 0) {
2390
            qemu_close(fd);
2391 2392 2393
            g_free(cluster);
            return ret;
        }
2394

2395
        if (write(fd, cluster, rest_size) < 0) {
2396
            qemu_close(fd);
2397 2398 2399
            g_free(cluster);
            return -2;
        }
2400 2401 2402 2403 2404

	offset += rest_size;
	c = c1;
    }

2405 2406
    if (ftruncate(fd, size)) {
        perror("ftruncate()");
2407
        qemu_close(fd);
2408
        g_free(cluster);
2409 2410
        return -4;
    }
2411
    qemu_close(fd);
2412
    g_free(cluster);
2413 2414 2415 2416 2417 2418 2419 2420 2421 2422

    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++) {
A
Anthony Liguori 已提交
2423
	mapping_t* mapping = array_get(&(s->mapping), i);
2424 2425 2426 2427 2428
	if (mapping->mode & MODE_DELETED) {
	    fprintf(stderr, "deleted\n");
	    continue;
	}
	assert(mapping->dir_index < s->directory.next);
A
Anthony Liguori 已提交
2429
	direntry_t* direntry = array_get(&(s->directory), mapping->dir_index);
2430 2431 2432 2433
	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);
2434 2435 2436 2437
	}
    }
}

2438 2439
/* test, if all direntries have mappings */
static void check2(BDRVVVFATState* s)
2440 2441
{
    int i;
2442
    int first_mapping = -1;
2443

2444
    for (i = 0; i < s->directory.next; i++) {
A
Anthony Liguori 已提交
2445
	direntry_t* direntry = array_get(&(s->directory), i);
2446

2447
	if (is_short_name(direntry) && begin_of_direntry(direntry)) {
A
Anthony Liguori 已提交
2448
	    mapping_t* mapping = find_mapping_for_cluster(s, begin_of_direntry(direntry));
2449 2450 2451 2452
	    assert(mapping);
	    assert(mapping->dir_index == i || is_dot(direntry));
	    assert(mapping->begin == begin_of_direntry(direntry) || is_dot(direntry));
	}
2453

2454 2455 2456
	if ((i % (0x10 * s->sectors_per_cluster)) == 0) {
	    /* cluster start */
	    int j, count = 0;
2457

2458
	    for (j = 0; j < s->mapping.next; j++) {
A
Anthony Liguori 已提交
2459
		mapping_t* mapping = array_get(&(s->mapping), j);
2460
		if (mapping->mode & MODE_DELETED)
2461
		    continue;
2462 2463 2464 2465 2466 2467 2468 2469 2470 2471
		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 {
A
Anthony Liguori 已提交
2472
			    mapping_t* parent = array_get(&(s->mapping), mapping->info.dir.parent_mapping_index);
2473 2474 2475 2476
			    assert(parent->mode & MODE_DIRECTORY);
			    assert(parent->info.dir.first_dir_index < mapping->info.dir.first_dir_index);
			}
		    }
2477
		}
2478 2479 2480 2481 2482 2483 2484
	    }
	    if (count == 0)
		first_mapping = -1;
	}
    }
}
#endif
2485

2486 2487 2488
static int handle_renames_and_mkdirs(BDRVVVFATState* s)
{
    int i;
2489

2490 2491 2492
#ifdef DEBUG
    fprintf(stderr, "handle_renames\n");
    for (i = 0; i < s->commits.next; i++) {
A
Anthony Liguori 已提交
2493
	commit_t* commit = array_get(&(s->commits), i);
2494 2495 2496 2497 2498
	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;) {
A
Anthony Liguori 已提交
2499
	commit_t* commit = array_get(&(s->commits), i);
2500
	if (commit->action == ACTION_RENAME) {
A
Anthony Liguori 已提交
2501
	    mapping_t* mapping = find_mapping_for_cluster(s,
2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513
		    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;
A
Anthony Liguori 已提交
2514
		direntry_t* direntry = array_get(&(s->directory),
2515 2516 2517 2518 2519 2520 2521
			mapping->info.dir.first_dir_index);
		uint32_t c = mapping->begin;
		int i = 0;

		/* recurse */
		while (!fat_eof(s, c)) {
		    do {
A
Anthony Liguori 已提交
2522
			direntry_t* d = direntry + i;
2523 2524

			if (is_file(d) || (is_directory(d) && !is_dot(d))) {
A
Anthony Liguori 已提交
2525
			    mapping_t* m = find_mapping_for_cluster(s,
2526 2527
				    begin_of_direntry(d));
			    int l = strlen(m->path);
2528
			    char* new_path = g_malloc(l + diff + 1);
2529 2530 2531

			    assert(!strncmp(m->path, mapping->path, l2));

B
blueswir1 已提交
2532 2533 2534
                            pstrcpy(new_path, l + diff + 1, mapping->path);
                            pstrcpy(new_path + l1, l + diff + 1 - l1,
                                    m->path + l2);
2535 2536

			    schedule_rename(s, m->begin, new_path);
2537
			}
2538 2539 2540
			i++;
		    } while((i % (0x10 * s->sectors_per_cluster)) != 0);
		    c = fat_get(s, c);
2541 2542 2543
		}
	    }

2544
            g_free(old_path);
2545 2546 2547
	    array_remove(&(s->commits), i);
	    continue;
	} else if (commit->action == ACTION_MKDIR) {
A
Anthony Liguori 已提交
2548
	    mapping_t* mapping;
2549 2550
	    int j, parent_path_len;

B
bellard 已提交
2551 2552 2553 2554 2555 2556 2557
#ifdef __MINGW32__
            if (mkdir(commit->path))
                return -5;
#else
            if (mkdir(commit->path, 0755))
                return -5;
#endif
2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575

	    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++) {
A
Anthony Liguori 已提交
2576
		mapping_t* m = array_get(&(s->mapping), j);
2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603
		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++) {
A
Anthony Liguori 已提交
2604
	commit_t* commit = array_get(&(s->commits), i);
2605 2606
	switch(commit->action) {
	case ACTION_RENAME: case ACTION_MKDIR:
2607
            abort();
2608 2609 2610
	    fail = -2;
	    break;
	case ACTION_WRITEOUT: {
B
Blue Swirl 已提交
2611 2612
#ifndef NDEBUG
            /* these variables are only used by assert() below */
A
Anthony Liguori 已提交
2613
	    direntry_t* entry = array_get(&(s->directory),
2614 2615
		    commit->param.writeout.dir_index);
	    uint32_t begin = begin_of_direntry(entry);
A
Anthony Liguori 已提交
2616
	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
B
Blue Swirl 已提交
2617
#endif
2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630

	    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;
A
Anthony Liguori 已提交
2631 2632
	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
	    direntry_t* entry;
2633
	    int i;
2634

2635 2636 2637 2638 2639
	    /* 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;
2640 2641
	    }

2642 2643 2644 2645
	    if (i >= s->directory.next) {
		fail = -6;
		continue;
	    }
2646

2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667
	    /* 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:
2668
            abort();
2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686
	}
    }
    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++) {
A
Anthony Liguori 已提交
2687
	    mapping_t* mapping = array_get(&(s->mapping), i);
2688
	    if (mapping->mode & MODE_DELETED) {
A
Anthony Liguori 已提交
2689
		direntry_t* entry = array_get(&(s->directory),
2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703
			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;
2704
			}
2705 2706

			for (j = 1; j < s->mapping.next; j++) {
A
Anthony Liguori 已提交
2707
			    mapping_t* m = array_get(&(s->mapping), j);
2708 2709 2710 2711 2712 2713 2714
			    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;
2715
			}
2716 2717
			remove_direntries(s, first_dir_index,
				next_dir_index - first_dir_index);
2718

2719
			deleted++;
2720
		    }
2721 2722 2723 2724
		} else {
		    if (unlink(mapping->path))
			return -4;
		    deleted++;
2725
		}
2726 2727
		DLOG(fprintf(stderr, "DELETE (%d)\n", i); print_mapping(mapping); print_direntry(entry));
		remove_mapping(s, i);
2728 2729 2730
	    }
	}
    }
2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755

    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);
2756
        abort();
2757 2758 2759
	return ret;
    }

2760
    /* copy FAT (with bdrv_read) */
2761 2762 2763 2764 2765 2766
    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);
2767
        abort();
2768 2769 2770 2771 2772 2773
	return ret;
    }

    ret = handle_commits(s);
    if (ret) {
	fprintf(stderr, "Error handling commits (%d)\n", ret);
2774
        abort();
2775 2776 2777 2778 2779 2780
	return ret;
    }

    ret = handle_deletes(s);
    if (ret) {
	fprintf(stderr, "Error deleting\n");
2781
        abort();
2782 2783 2784
	return ret;
    }

K
Kevin Wolf 已提交
2785 2786 2787
    if (s->qcow->drv->bdrv_make_empty) {
        s->qcow->drv->bdrv_make_empty(s->qcow);
    }
2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803

    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);
}

2804
static int vvfat_write(BlockDriverState *bs, int64_t sector_num,
2805 2806
                    const uint8_t *buf, int nb_sectors)
{
2807
    BDRVVVFATState *s = bs->opaque;
2808 2809 2810 2811
    int i, ret;

DLOG(checkpoint());

2812 2813 2814 2815 2816
    /* Check if we're operating in read-only mode */
    if (s->qcow == NULL) {
        return -EACCES;
    }

2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829
    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);) {
A
Anthony Liguori 已提交
2830
	mapping_t* mapping = find_mapping_for_cluster(s, i);
2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841
	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;
A
Anthony Liguori 已提交
2842
		const direntry_t* direntries;
2843 2844 2845 2846 2847 2848 2849 2850
		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;
2851
		dir_index  = mapping->dir_index +
2852
		    0x10 * (begin - mapping->begin * s->sectors_per_cluster);
A
Anthony Liguori 已提交
2853
		direntries = (direntry_t*)(buf + 0x200 * (begin - sector_num));
2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865

		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),
A
Anthony Liguori 已提交
2866
				    sizeof(direntry_t))) {
2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881
			    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));
K
Kevin Wolf 已提交
2882
    ret = bdrv_write(s->qcow, sector_num, buf, nb_sectors);
2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900
    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;
}

2901 2902 2903
static int coroutine_fn
vvfat_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                 QEMUIOVector *qiov, int flags)
2904 2905 2906
{
    int ret;
    BDRVVVFATState *s = bs->opaque;
2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919
    uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
    int nb_sectors = bytes >> BDRV_SECTOR_BITS;
    void *buf;

    assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
    assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);

    buf = g_try_malloc(bytes);
    if (bytes && buf == NULL) {
        return -ENOMEM;
    }
    qemu_iovec_to_buf(qiov, 0, buf, bytes);

2920 2921 2922
    qemu_co_mutex_lock(&s->lock);
    ret = vvfat_write(bs, sector_num, buf, nb_sectors);
    qemu_co_mutex_unlock(&s->lock);
2923 2924 2925

    g_free(buf);

2926 2927 2928
    return ret;
}

2929
static int64_t coroutine_fn vvfat_co_get_block_status(BlockDriverState *bs,
2930
	int64_t sector_num, int nb_sectors, int *n, BlockDriverState **file)
2931 2932 2933
{
    BDRVVVFATState* s = bs->opaque;
    *n = s->sector_count - sector_num;
2934 2935 2936 2937 2938 2939
    if (*n > nb_sectors) {
        *n = nb_sectors;
    } else if (*n < 0) {
        return 0;
    }
    return BDRV_BLOCK_DATA;
2940 2941
}

2942 2943 2944 2945
static int coroutine_fn
write_target_commit(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                    QEMUIOVector *qiov, int flags)
{
2946
    BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
2947 2948 2949 2950
    return try_commit(s);
}

static void write_target_close(BlockDriverState *bs) {
2951
    BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
F
Fam Zheng 已提交
2952
    bdrv_unref(s->qcow);
2953
    g_free(s->qcow_filename);
2954 2955 2956
}

static BlockDriver vvfat_write_target = {
2957
    .format_name        = "vvfat_write_target",
2958
    .bdrv_co_pwritev    = write_target_commit,
2959
    .bdrv_close         = write_target_close,
2960 2961
};

2962
static int enable_write_target(BDRVVVFATState *s, Error **errp)
2963
{
2964
    BlockDriver *bdrv_qcow = NULL;
2965
    BlockDriverState *backing;
2966
    QemuOpts *opts = NULL;
K
Kevin Wolf 已提交
2967
    int ret;
2968
    int size = sector2cluster(s, s->sector_count);
2969 2970
    QDict *options;

2971 2972
    s->used_clusters = calloc(size, 1);

A
Anthony Liguori 已提交
2973
    array_init(&(s->commits), sizeof(commit_t));
2974

2975 2976
    s->qcow_filename = g_malloc(PATH_MAX);
    ret = get_tmp_filename(s->qcow_filename, PATH_MAX);
2977
    if (ret < 0) {
2978
        error_setg_errno(errp, -ret, "can't create temporary file");
2979
        goto err;
2980
    }
K
Kevin Wolf 已提交
2981 2982

    bdrv_qcow = bdrv_find_format("qcow");
2983 2984 2985 2986 2987 2988
    if (!bdrv_qcow) {
        error_setg(errp, "Failed to locate qcow driver");
        ret = -ENOENT;
        goto err;
    }

C
Chunyan Liu 已提交
2989
    opts = qemu_opts_create(bdrv_qcow->create_opts, NULL, 0, &error_abort);
2990 2991
    qemu_opt_set_number(opts, BLOCK_OPT_SIZE, s->sector_count * 512,
                        &error_abort);
2992
    qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, "fat:", &error_abort);
K
Kevin Wolf 已提交
2993

C
Chunyan Liu 已提交
2994
    ret = bdrv_create(bdrv_qcow, s->qcow_filename, opts, errp);
2995
    qemu_opts_del(opts);
2996 2997 2998
    if (ret < 0) {
        goto err;
    }
K
Kevin Wolf 已提交
2999

3000 3001
    options = qdict_new();
    qdict_put(options, "driver", qstring_from_str("qcow"));
M
Max Reitz 已提交
3002 3003 3004 3005
    s->qcow = bdrv_open(s->qcow_filename, NULL, options,
                        BDRV_O_RDWR | BDRV_O_NO_FLUSH, errp);
    if (!s->qcow) {
        ret = -EINVAL;
3006
        goto err;
K
Kevin Wolf 已提交
3007
    }
3008 3009 3010 3011 3012

#ifndef _WIN32
    unlink(s->qcow_filename);
#endif

3013 3014 3015 3016
    backing = bdrv_new();
    bdrv_set_backing_hd(s->bs, backing);
    bdrv_unref(backing);

3017 3018 3019
    s->bs->backing->bs->drv = &vvfat_write_target;
    s->bs->backing->bs->opaque = g_new(void *, 1);
    *(void**)s->bs->backing->bs->opaque = s;
3020

3021
    return 0;
3022 3023 3024 3025 3026

err:
    g_free(s->qcow_filename);
    s->qcow_filename = NULL;
    return ret;
3027 3028 3029 3030 3031 3032 3033 3034 3035 3036
}

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));
3037
    g_free(s->cluster_buffer);
K
Kevin Wolf 已提交
3038 3039 3040 3041 3042

    if (s->qcow) {
        migrate_del_blocker(s->migration_blocker);
        error_free(s->migration_blocker);
    }
3043 3044
}

3045
static BlockDriver bdrv_vvfat = {
3046 3047 3048 3049 3050 3051 3052 3053
    .format_name            = "vvfat",
    .protocol_name          = "fat",
    .instance_size          = sizeof(BDRVVVFATState),

    .bdrv_parse_filename    = vvfat_parse_filename,
    .bdrv_file_open         = vvfat_open,
    .bdrv_close             = vvfat_close,

3054 3055
    .bdrv_co_preadv         = vvfat_co_preadv,
    .bdrv_co_pwritev        = vvfat_co_pwritev,
3056
    .bdrv_co_get_block_status = vvfat_co_get_block_status,
3057 3058
};

3059 3060 3061 3062 3063 3064 3065
static void bdrv_vvfat_init(void)
{
    bdrv_register(&bdrv_vvfat);
}

block_init(bdrv_vvfat_init);

3066
#ifdef DEBUG
3067
static void checkpoint(void) {
A
Anthony Liguori 已提交
3068
    assert(((mapping_t*)array_get(&(vvv->mapping), 0))->end == 2);
3069 3070 3071 3072
    check1(vvv);
    check2(vvv);
    assert(!vvv->current_mapping || vvv->current_fd || (vvv->current_mapping->mode & MODE_DIRECTORY));
#if 0
A
Anthony Liguori 已提交
3073
    if (((direntry_t*)vvv->directory.pointer)[1].attributes != 0xf)
3074
	fprintf(stderr, "Nonono!\n");
A
Anthony Liguori 已提交
3075 3076
    mapping_t* mapping;
    direntry_t* direntry;
3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087
    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
}
#endif