vvfat.c 80.5 KB
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/* vim:set shiftwidth=4 ts=8: */
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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.
 */
#include <sys/stat.h>
#include <dirent.h>
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#include "qemu-common.h"
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#include "block_int.h"
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#include "module.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

#undef stderr
#define stderr STDERR
FILE* stderr = NULL;
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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];
    uint8_t extension[3];
    uint8_t attributes;
    uint8_t reserved[2];
    uint16_t ctime;
    uint16_t cdate;
    uint16_t adate;
    uint16_t begin_hi;
    uint16_t mtime;
    uint16_t mdate;
    uint16_t begin;
    uint32_t size;
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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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    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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} 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(BlockDriverState* bs, mbr_chs_t * chs, int spos){
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    int head,sector;
    sector   = spos % (bs->secs);  spos/= bs->secs;
    head     = spos % (bs->heads); spos/= bs->heads;
    if(spos >= bs->cyls){
        /* Overflow,
        it happens if 32bit sector positions are used, while CHS is only 24bit.
        Windows/Dos is said to take 1023/255/63 as nonrepresentable CHS */
        chs->head     = 0xFF;
        chs->sector   = 0xFF;
        chs->cylinder = 0xFF;
        return 1;
    }
    chs->head     = (uint8_t)head;
    chs->sector   = (uint8_t)( (sector+1) | ((spos>>8)<<6) );
    chs->cylinder = (uint8_t)spos;
    return 0;
}
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static void init_mbr(BDRVVVFATState* s)
{
    /* 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 */
    lba = sector2CHS(s->bs, &partition->start_CHS, s->first_sectors_number-1);
    lba|= sector2CHS(s->bs, &partition->end_CHS,   s->sector_count);

    /*LBA partitions are identified only by start/length_sector_long not by CHS*/
    partition->start_sector_long =cpu_to_le32(s->first_sectors_number-1);
    partition->length_sector_long=cpu_to_le32(s->sector_count - s->first_sectors_number+1);

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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<11;i++) {
        unsigned char c;

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        c = (i < 8) ? entry->name[i] : entry->extension[i-8];
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        chksum=(((chksum&0xfe)>>1)|((chksum&0x01)?0x80:0)) + c;
    }
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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;
#ifdef _WIN32
    t=localtime(&time); /* this is not thread safe */
#else
    struct tm t1;
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    t = &t1;
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    localtime_r(&time,t);
#endif
    if(return_time)
	return cpu_to_le16((t->tm_sec/2)|(t->tm_min<<5)|(t->tm_hour<<11));
    return cpu_to_le16((t->tm_mday)|((t->tm_mon+1)<<5)|((t->tm_year-80)<<9));
}

static inline void fat_set(BDRVVVFATState* s,unsigned int cluster,uint32_t value)
{
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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;
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	return ((x[0]|(x[1]<<8))>>(cluster&1?4:0))&0x0fff;
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    }
}

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)
{
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    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);
    }
593
    memset(s->fat.pointer,0,s->fat.size);
594

595 596 597
    switch(s->fat_type) {
	case 12: s->max_fat_value=0xfff; break;
	case 16: s->max_fat_value=0xffff; break;
598
	case 32: s->max_fat_value=0x0fffffff; break;
599 600 601 602 603
	default: s->max_fat_value=0; /* error... */
    }

}

604 605
/* 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
606
static inline direntry_t* create_short_and_long_name(BDRVVVFATState* s,
607
	unsigned int directory_start, const char* filename, int is_dot)
608
{
609
    int i,j,long_index=s->directory.next;
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Anthony Liguori 已提交
610 611
    direntry_t* entry = NULL;
    direntry_t* entry_long = NULL;
612 613 614 615 616 617 618

    if(is_dot) {
	entry=array_get_next(&(s->directory));
	memset(entry->name,0x20,11);
	memcpy(entry->name,filename,strlen(filename));
	return entry;
    }
619

620
    entry_long=create_long_filename(s,filename);
621

622
    i = strlen(filename);
623 624 625 626 627 628
    for(j = i - 1; j>0  && filename[j]!='.';j--);
    if (j > 0)
	i = (j > 8 ? 8 : j);
    else if (i > 8)
	i = 8;

629 630
    entry=array_get_next(&(s->directory));
    memset(entry->name,0x20,11);
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blueswir1 已提交
631
    memcpy(entry->name, filename, i);
632

633 634 635
    if(j > 0)
	for (i = 0; i < 3 && filename[j+1+i]; i++)
	    entry->extension[i] = filename[j+1+i];
636 637 638

    /* upcase & remove unwanted characters */
    for(i=10;i>=0;i--) {
639
	if(i==10 || i==7) for(;i>0 && entry->name[i]==' ';i--);
640
	if(entry->name[i]<=' ' || entry->name[i]>0x7f
641
		|| strchr(".*?<>|\":/\\[];,+='",entry->name[i]))
642 643 644 645 646 647 648
	    entry->name[i]='_';
        else if(entry->name[i]>='a' && entry->name[i]<='z')
            entry->name[i]+='A'-'a';
    }

    /* mangle duplicates */
    while(1) {
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Anthony Liguori 已提交
649
	direntry_t* entry1=array_get(&(s->directory),directory_start);
650 651 652
	int j;

	for(;entry1<entry;entry1++)
653
	    if(!is_long_name(entry1) && !memcmp(entry1->name,entry->name,11))
654 655 656 657
		break; /* found dupe */
	if(entry1==entry) /* no dupe found */
	    break;

658
	/* use all 8 characters of name */
659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681
	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);
682
	while(entry_long<entry && is_long_name(entry_long)) {
683 684 685 686 687 688 689 690
	    entry_long->reserved[1]=chksum;
	    entry_long++;
	}
    }

    return entry;
}

691 692 693 694
/*
 * Read a directory. (the index of the corresponding mapping must be passed).
 */
static int read_directory(BDRVVVFATState* s, int mapping_index)
695
{
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Anthony Liguori 已提交
696 697
    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
    direntry_t* direntry;
698 699 700
    const char* dirname = mapping->path;
    int first_cluster = mapping->begin;
    int parent_index = mapping->info.dir.parent_mapping_index;
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Anthony Liguori 已提交
701
    mapping_t* parent_mapping = (mapping_t*)
702
        (parent_index >= 0 ? array_get(&(s->mapping), parent_index) : NULL);
703
    int first_cluster_of_parent = parent_mapping ? parent_mapping->begin : -1;
704 705 706 707 708

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

709 710 711 712
    assert(mapping->mode & MODE_DIRECTORY);

    if(!dir) {
	mapping->end = mapping->begin;
713
	return -1;
714
    }
715

716 717 718
    i = mapping->info.dir.first_dir_index =
	    first_cluster == 0 ? 0 : s->directory.next;

719
    /* actually read the directory, and allocate the mappings */
720 721 722
    while((entry=readdir(dir))) {
	unsigned int length=strlen(dirname)+2+strlen(entry->d_name);
        char* buffer;
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Anthony Liguori 已提交
723
	direntry_t* direntry;
724
        struct stat st;
725 726 727
	int is_dot=!strcmp(entry->d_name,".");
	int is_dotdot=!strcmp(entry->d_name,"..");

728
	if(first_cluster == 0 && (is_dotdot || is_dot))
729
	    continue;
730

731
	buffer=(char*)g_malloc(length);
732 733 734
	snprintf(buffer,length,"%s/%s",dirname,entry->d_name);

	if(stat(buffer,&st)<0) {
735
            g_free(buffer);
736 737 738 739
            continue;
	}

	/* create directory entry for this file */
740 741
	direntry=create_short_and_long_name(s, i, entry->d_name,
		is_dot || is_dotdot);
742 743 744 745 746 747 748 749 750
	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)
751
	    set_begin_of_direntry(direntry, first_cluster_of_parent);
752
	else if(is_dot)
753
	    set_begin_of_direntry(direntry, first_cluster);
754
	else
755 756 757
	    direntry->begin=0; /* do that later */
        if (st.st_size > 0x7fffffff) {
	    fprintf(stderr, "File %s is larger than 2GB\n", buffer);
758
            g_free(buffer);
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            closedir(dir);
760 761 762
	    return -2;
        }
	direntry->size=cpu_to_le32(S_ISDIR(st.st_mode)?0:st.st_size);
763 764

	/* create mapping for this file */
765
	if(!is_dot && !is_dotdot && (S_ISDIR(st.st_mode) || st.st_size)) {
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Anthony Liguori 已提交
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	    s->current_mapping=(mapping_t*)array_get_next(&(s->mapping));
767 768
	    s->current_mapping->begin=0;
	    s->current_mapping->end=st.st_size;
769 770 771 772
	    /*
	     * we get the direntry of the most recent direntry, which
	     * contains the short name and all the relevant information.
	     */
773
	    s->current_mapping->dir_index=s->directory.next-1;
774 775 776 777 778 779 780 781 782 783 784 785
	    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;
786 787 788 789 790 791
	}
    }
    closedir(dir);

    /* fill with zeroes up to the end of the cluster */
    while(s->directory.next%(0x10*s->sectors_per_cluster)) {
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Anthony Liguori 已提交
792 793
	direntry_t* direntry=array_get_next(&(s->directory));
	memset(direntry,0,sizeof(direntry_t));
794 795
    }

796 797 798 799 800 801
/* 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);
802
	s->directory.next = ROOT_ENTRIES;
803
	memset(array_get(&(s->directory), cur), 0,
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Anthony Liguori 已提交
804
		(ROOT_ENTRIES - cur) * sizeof(direntry_t));
805
    }
806

807
     /* reget the mapping, since s->mapping was possibly realloc()ed */
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Anthony Liguori 已提交
808
    mapping = (mapping_t*)array_get(&(s->mapping), mapping_index);
809 810 811 812
    first_cluster += (s->directory.next - mapping->info.dir.first_dir_index)
	* 0x20 / s->cluster_size;
    mapping->end = first_cluster;

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Anthony Liguori 已提交
813
    direntry = (direntry_t*)array_get(&(s->directory), mapping->dir_index);
814
    set_begin_of_direntry(direntry, mapping->begin);
815

816 817
    return 0;
}
818

819 820 821 822
static inline uint32_t sector2cluster(BDRVVVFATState* s,off_t sector_num)
{
    return (sector_num-s->faked_sectors)/s->sectors_per_cluster;
}
823

824 825 826 827
static inline off_t cluster2sector(BDRVVVFATState* s, uint32_t cluster_num)
{
    return s->faked_sectors + s->sectors_per_cluster * cluster_num;
}
828

829 830
static int init_directories(BDRVVVFATState* s,
	const char* dirname)
831
{
A
Anthony Liguori 已提交
832 833
    bootsector_t* bootsector;
    mapping_t* mapping;
834 835 836 837 838 839
    unsigned int i;
    unsigned int cluster;

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

    s->cluster_size=s->sectors_per_cluster*0x200;
840
    s->cluster_buffer=g_malloc(s->cluster_size);
841 842 843 844 845 846 847 848 849 850

    /*
     * 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 */
851

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Anthony Liguori 已提交
852 853
    array_init(&(s->mapping),sizeof(mapping_t));
    array_init(&(s->directory),sizeof(direntry_t));
854 855 856

    /* add volume label */
    {
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Anthony Liguori 已提交
857
	direntry_t* entry=array_get_next(&(s->directory));
858
	entry->attributes=0x28; /* archive | volume label */
859 860
	memcpy(entry->name,"QEMU VVF",8);
	memcpy(entry->extension,"AT ",3);
861 862 863 864 865
    }

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

866 867 868 869 870 871 872 873
    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;
874
    mapping->path = g_strdup(dirname);
875 876 877 878 879 880 881 882
    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++) {
883
	/* MS-DOS expects the FAT to be 0 for the root directory
884 885 886 887 888 889 890 891 892 893
	 * (except for the media byte). */
	/* LATER TODO: still true for FAT32? */
	int fix_fat = (i != 0);
	mapping = array_get(&(s->mapping), i);

        if (mapping->mode & MODE_DIRECTORY) {
	    mapping->begin = cluster;
	    if(read_directory(s, i)) {
		fprintf(stderr, "Could not read directory %s\n",
			mapping->path);
894 895
		return -1;
	    }
896 897 898
	    mapping = array_get(&(s->mapping), i);
	} else {
	    assert(mapping->mode == MODE_UNDEFINED);
899
	    mapping->mode=MODE_NORMAL;
900 901
	    mapping->begin = cluster;
	    if (mapping->end > 0) {
A
Anthony Liguori 已提交
902
		direntry_t* direntry = array_get(&(s->directory),
903 904 905 906 907 908 909
			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;
910
	    }
911 912 913 914
	}

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

915 916 917 918
	/* next free cluster */
	cluster = mapping->end;

	if(cluster > s->cluster_count) {
919 920
	    fprintf(stderr,"Directory does not fit in FAT%d (capacity %.2f MB)\n",
		    s->fat_type, s->sector_count / 2000.0);
921 922 923
	    return -EINVAL;
	}

924 925
	/* fix fat for entry */
	if (fix_fat) {
926
	    int j;
927 928 929 930
	    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);
	}
931 932
    }

933 934 935 936 937 938 939
    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);
940

941 942
    s->current_mapping = NULL;

A
Anthony Liguori 已提交
943
    bootsector=(bootsector_t*)(s->first_sectors+(s->first_sectors_number-1)*0x200);
944 945 946 947 948 949 950 951 952
    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);
953
    bootsector->total_sectors16=s->sector_count>0xffff?0:cpu_to_le16(s->sector_count);
954
    bootsector->media_type=(s->first_sectors_number>1?0xf8:0xf0); /* media descriptor (f8=hd, f0=3.5 fd)*/
955
    s->fat.pointer[0] = bootsector->media_type;
956
    bootsector->sectors_per_fat=cpu_to_le16(s->sectors_per_fat);
957 958
    bootsector->sectors_per_track=cpu_to_le16(s->bs->secs);
    bootsector->number_of_heads=cpu_to_le16(s->bs->heads);
959
    bootsector->hidden_sectors=cpu_to_le32(s->first_sectors_number==1?0:0x3f);
960
    bootsector->total_sectors=cpu_to_le32(s->sector_count>0xffff?s->sector_count:0);
961

962
    /* LATER TODO: if FAT32, this is wrong */
963
    bootsector->u.fat16.drive_number=s->first_sectors_number==1?0:0x80; /* fda=0, hda=0x80 */
964 965 966 967 968 969 970 971 972 973 974
    bootsector->u.fat16.current_head=0;
    bootsector->u.fat16.signature=0x29;
    bootsector->u.fat16.id=cpu_to_le32(0xfabe1afd);

    memcpy(bootsector->u.fat16.volume_label,"QEMU VVFAT ",11);
    memcpy(bootsector->fat_type,(s->fat_type==12?"FAT12   ":s->fat_type==16?"FAT16   ":"FAT32   "),8);
    bootsector->magic[0]=0x55; bootsector->magic[1]=0xaa;

    return 0;
}

B
bellard 已提交
975
#ifdef DEBUG
976
static BDRVVVFATState *vvv = NULL;
B
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977
#endif
978 979 980 981

static int enable_write_target(BDRVVVFATState *s);
static int is_consistent(BDRVVVFATState *s);

B
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982
static int vvfat_open(BlockDriverState *bs, const char* dirname, int flags)
983 984 985 986
{
    BDRVVVFATState *s = bs->opaque;
    int i;

B
bellard 已提交
987
#ifdef DEBUG
988
    vvv = s;
B
bellard 已提交
989
#endif
990 991 992 993 994 995 996 997 998 999

DLOG(if (stderr == NULL) {
    stderr = fopen("vvfat.log", "a");
    setbuf(stderr, NULL);
})

    s->bs = bs;

    /* LATER TODO: if FAT32, adjust */
    s->sectors_per_cluster=0x10;
1000 1001 1002 1003

    s->current_cluster=0xffffffff;

    s->first_sectors_number=0x40;
1004 1005 1006 1007 1008 1009
    /* 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;
1010

1011 1012 1013 1014 1015 1016 1017 1018 1019 1020
    if (!strstart(dirname, "fat:", NULL))
	return -1;

    if (strstr(dirname, ":32:")) {
	fprintf(stderr, "Big fat greek warning: FAT32 has not been tested. You are welcome to do so!\n");
	s->fat_type = 32;
    } else if (strstr(dirname, ":16:")) {
	s->fat_type = 16;
    } else if (strstr(dirname, ":12:")) {
	s->fat_type = 12;
1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041
    }

    if (strstr(dirname, ":floppy:")) {
	/* 1.44MB or 2.88MB floppy.  2.88MB can be FAT12 (default) or FAT16. */
	if (!s->fat_type) {
	    s->fat_type = 12;
	    bs->secs = 36;
	    s->sectors_per_cluster=2;
	} else {
	    bs->secs=(s->fat_type == 12 ? 18 : 36);
	    s->sectors_per_cluster=1;
	}
	s->first_sectors_number = 1;
	bs->cyls=80; bs->heads=2;
    } else {
	/* 32MB or 504MB disk*/
	if (!s->fat_type) {
	    s->fat_type = 16;
	}
	bs->cyls=(s->fat_type == 12 ? 64 : 1024);
	bs->heads=16; bs->secs=63;
1042
    }
1043

1044 1045
    s->sector_count=bs->cyls*bs->heads*bs->secs-(s->first_sectors_number-1);

T
ths 已提交
1046 1047 1048 1049 1050 1051
    if (strstr(dirname, ":rw:")) {
	if (enable_write_target(s))
	    return -1;
	bs->read_only = 0;
    }

1052 1053
    i = strrchr(dirname, ':') - dirname;
    assert(i >= 3);
1054
    if (dirname[i-2] == ':' && qemu_isalpha(dirname[i-1]))
1055 1056 1057 1058 1059 1060
	/* workaround for DOS drive names */
	dirname += i-1;
    else
	dirname += i+1;

    bs->total_sectors=bs->cyls*bs->heads*bs->secs;
T
ths 已提交
1061

1062
    if(init_directories(s, dirname))
1063 1064
	return -1;

T
ths 已提交
1065 1066
    s->sector_count = s->faked_sectors + s->sectors_per_cluster*s->cluster_count;

1067 1068
    if(s->first_sectors_number==0x40)
	init_mbr(s);
1069 1070
    else {
        /* MS-DOS does not like to know about CHS (?). */
1071
	bs->heads = bs->cyls = bs->secs = 0;
1072
    }
1073 1074

    //    assert(is_consistent(s));
1075
    qemu_co_mutex_init(&s->lock);
1076 1077 1078 1079 1080 1081
    return 0;
}

static inline void vvfat_close_current_file(BDRVVVFATState *s)
{
    if(s->current_mapping) {
1082 1083 1084 1085 1086
	s->current_mapping = NULL;
	if (s->current_fd) {
		close(s->current_fd);
		s->current_fd = 0;
	}
1087
    }
1088
    s->current_cluster = -1;
1089 1090 1091 1092 1093 1094 1095 1096
}

/* 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) {
1097
        int index3;
A
Anthony Liguori 已提交
1098
	mapping_t* mapping;
1099 1100
	index3=(index1+index2)/2;
	mapping=array_get(&(s->mapping),index3);
1101 1102
	assert(mapping->begin < mapping->end);
	if(mapping->begin>=cluster_num) {
1103 1104
	    assert(index2!=index3 || index2==0);
	    if(index2==index3)
1105
		return index1;
1106 1107 1108
	    index2=index3;
	} else {
	    if(index1==index3)
1109
		return mapping->end<=cluster_num ? index2 : index1;
1110 1111 1112
	    index1=index3;
	}
	assert(index1<=index2);
1113 1114
	DLOG(mapping=array_get(&(s->mapping),index1);
	assert(mapping->begin<=cluster_num);
1115
	assert(index2 >= s->mapping.next ||
1116 1117
		((mapping = array_get(&(s->mapping),index2)) &&
		mapping->end>cluster_num)));
1118 1119 1120
    }
}

A
Anthony Liguori 已提交
1121
static inline mapping_t* find_mapping_for_cluster(BDRVVVFATState* s,int cluster_num)
1122 1123
{
    int index=find_mapping_for_cluster_aux(s,cluster_num,0,s->mapping.next);
A
Anthony Liguori 已提交
1124
    mapping_t* mapping;
1125
    if(index>=s->mapping.next)
1126
        return NULL;
1127 1128
    mapping=array_get(&(s->mapping),index);
    if(mapping->begin>cluster_num)
1129
        return NULL;
1130
    assert(mapping->begin<=cluster_num && mapping->end>cluster_num);
1131 1132 1133
    return mapping;
}

A
Anthony Liguori 已提交
1134
static int open_file(BDRVVVFATState* s,mapping_t* mapping)
1135 1136 1137 1138
{
    if(!mapping)
	return -1;
    if(!s->current_mapping ||
1139
	    strcmp(s->current_mapping->path,mapping->path)) {
1140
	/* open file */
1141
	int fd = open(mapping->path, O_RDONLY | O_BINARY | O_LARGEFILE);
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155
	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;
1156
	assert(!s->current_mapping || s->current_fd || (s->current_mapping->mode & MODE_DIRECTORY));
1157 1158 1159 1160
	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
1161
	    mapping_t* mapping=find_mapping_for_cluster(s,cluster_num);
1162 1163 1164 1165 1166 1167 1168 1169

	    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
1170
		s->cluster = (unsigned char*)s->directory.pointer+offset
1171 1172 1173 1174 1175 1176 1177 1178
			+ 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))
1179
		return -2;
1180 1181
	} else if (s->current_mapping->mode & MODE_DIRECTORY)
	    goto read_cluster_directory;
1182

1183 1184 1185
	assert(s->current_fd);

	offset=s->cluster_size*(cluster_num-s->current_mapping->begin)+s->current_mapping->info.file.offset;
1186 1187
	if(lseek(s->current_fd, offset, SEEK_SET)!=offset)
	    return -3;
1188
	s->cluster=s->cluster_buffer;
1189 1190 1191 1192 1193 1194 1195 1196 1197 1198
	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;
}

1199
#ifdef DEBUG
A
Anthony Liguori 已提交
1200
static void print_direntry(const direntry_t* direntry)
1201
{
1202 1203 1204
    int j = 0;
    char buffer[1024];

K
Kevin Wolf 已提交
1205
    fprintf(stderr, "direntry %p: ", direntry);
1206 1207
    if(!direntry)
	return;
1208
    if(is_long_name(direntry)) {
1209 1210 1211
	unsigned char* c=(unsigned char*)direntry;
	int i;
	for(i=1;i<11 && c[i] && c[i]!=0xff;i+=2)
1212
#define ADD_CHAR(c) {buffer[j] = (c); if (buffer[j] < ' ') buffer[j] = 0xb0; j++;}
1213
	    ADD_CHAR(c[i]);
1214
	for(i=14;i<26 && c[i] && c[i]!=0xff;i+=2)
1215
	    ADD_CHAR(c[i]);
1216
	for(i=28;i<32 && c[i] && c[i]!=0xff;i+=2)
1217 1218 1219
	    ADD_CHAR(c[i]);
	buffer[j] = 0;
	fprintf(stderr, "%s\n", buffer);
1220 1221 1222
    } else {
	int i;
	for(i=0;i<11;i++)
1223 1224 1225 1226
	    ADD_CHAR(direntry->name[i]);
	buffer[j] = 0;
	fprintf(stderr,"%s attributes=0x%02x begin=%d size=%d\n",
		buffer,
1227
		direntry->attributes,
1228
		begin_of_direntry(direntry),le32_to_cpu(direntry->size));
1229 1230 1231
    }
}

A
Anthony Liguori 已提交
1232
static void print_mapping(const mapping_t* mapping)
1233
{
K
Kevin Wolf 已提交
1234 1235 1236 1237 1238
    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);

1239 1240 1241 1242
    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);
1243
}
1244
#endif
1245

1246
static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
1247
                    uint8_t *buf, int nb_sectors)
1248
{
1249
    BDRVVVFATState *s = bs->opaque;
1250 1251
    int i;

1252
    for(i=0;i<nb_sectors;i++,sector_num++) {
1253
	if (sector_num >= bs->total_sectors)
1254 1255 1256
	   return -1;
	if (s->qcow) {
	    int n;
K
Kevin Wolf 已提交
1257
            if (bdrv_is_allocated(s->qcow, sector_num, nb_sectors-i, &n)) {
1258
DLOG(fprintf(stderr, "sectors %d+%d allocated\n", (int)sector_num, n));
K
Kevin Wolf 已提交
1259 1260 1261 1262 1263 1264 1265
                if (bdrv_read(s->qcow, sector_num, buf + i*0x200, n)) {
                    return -1;
                }
                i += n - 1;
                sector_num += n - 1;
                continue;
            }
1266
DLOG(fprintf(stderr, "sector %d not allocated\n", (int)sector_num));
1267
	}
1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278
	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;
1279
	    if(cluster_num > s->cluster_count || read_cluster(s, cluster_num) != 0) {
1280 1281 1282
		/* LATER TODO: strict: return -1; */
		memset(buf+i*0x200,0,0x200);
		continue;
1283
	    }
1284
	    memcpy(buf+i*0x200,s->cluster+sector_offset_in_cluster*0x200,0x200);
1285 1286 1287 1288 1289
	}
    }
    return 0;
}

1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300
static coroutine_fn int vvfat_co_read(BlockDriverState *bs, int64_t sector_num,
                                      uint8_t *buf, int nb_sectors)
{
    int ret;
    BDRVVVFATState *s = bs->opaque;
    qemu_co_mutex_lock(&s->lock);
    ret = vvfat_read(bs, sector_num, buf, nb_sectors);
    qemu_co_mutex_unlock(&s->lock);
    return ret;
}

1301
/* LATER TODO: statify all functions */
1302

1303 1304
/*
 * Idea of the write support (use snapshot):
1305
 *
1306 1307
 * 1. check if all data is consistent, recording renames, modifications,
 *    new files and directories (in s->commits).
1308
 *
1309
 * 2. if the data is not consistent, stop committing
1310
 *
1311 1312
 * 3. handle renames, and create new files and directories (do not yet
 *    write their contents)
1313
 *
1314 1315
 * 4. walk the directories, fixing the mapping and direntries, and marking
 *    the handled mappings as not deleted
1316
 *
1317
 * 5. commit the contents of the files
1318
 *
1319
 * 6. handle deleted files and directories
1320 1321 1322
 *
 */

A
Anthony Liguori 已提交
1323
typedef struct commit_t {
1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334
    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
1335
} commit_t;
1336

1337
static void clear_commits(BDRVVVFATState* s)
1338 1339
{
    int i;
1340 1341
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
1342
	commit_t* commit = array_get(&(s->commits), i);
1343 1344 1345
	assert(commit->path || commit->action == ACTION_WRITEOUT);
	if (commit->action != ACTION_WRITEOUT) {
	    assert(commit->path);
1346
            g_free(commit->path);
1347 1348
	} else
	    assert(commit->path == NULL);
1349
    }
1350
    s->commits.next = 0;
1351 1352
}

1353 1354
static void schedule_rename(BDRVVVFATState* s,
	uint32_t cluster, char* new_path)
1355
{
A
Anthony Liguori 已提交
1356
    commit_t* commit = array_get_next(&(s->commits));
1357 1358 1359
    commit->path = new_path;
    commit->param.rename.cluster = cluster;
    commit->action = ACTION_RENAME;
1360 1361
}

1362 1363
static void schedule_writeout(BDRVVVFATState* s,
	int dir_index, uint32_t modified_offset)
1364
{
A
Anthony Liguori 已提交
1365
    commit_t* commit = array_get_next(&(s->commits));
1366 1367 1368 1369
    commit->path = NULL;
    commit->param.writeout.dir_index = dir_index;
    commit->param.writeout.modified_offset = modified_offset;
    commit->action = ACTION_WRITEOUT;
1370 1371
}

1372 1373
static void schedule_new_file(BDRVVVFATState* s,
	char* path, uint32_t first_cluster)
1374
{
A
Anthony Liguori 已提交
1375
    commit_t* commit = array_get_next(&(s->commits));
1376 1377 1378 1379 1380 1381 1382
    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
1383
    commit_t* commit = array_get_next(&(s->commits));
1384 1385 1386 1387 1388 1389
    commit->path = path;
    commit->param.mkdir.cluster = cluster;
    commit->action = ACTION_MKDIR;
}

typedef struct {
1390 1391 1392 1393 1394 1395
    /*
     * 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];
1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407
    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
1408
	const direntry_t* direntry)
1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419
{
    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
1420
	lfn->name[lfn->sequence_number * 13] = 0;
1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440
    } 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;
1441
    }
1442 1443

    if (pointer[0] & 0x40)
T
ths 已提交
1444
	lfn->len = offset + strlen((char*)lfn->name + offset);
1445

1446 1447 1448
    return 0;
}

1449 1450
/* 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
1451
	long_file_name* lfn, direntry_t* direntry)
1452
{
1453
    int i, j;
1454

1455 1456 1457 1458 1459 1460 1461 1462
    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)
1463
	    lfn->name[i] = qemu_tolower(direntry->name[i]);
1464 1465
	else
	    lfn->name[i] = direntry->name[i];
1466 1467
    }

1468 1469 1470 1471 1472 1473 1474 1475
    for (j = 2; j >= 0 && direntry->extension[j] == ' '; j--);
    if (j >= 0) {
	lfn->name[i++] = '.';
	lfn->name[i + j + 1] = '\0';
	for (;j >= 0; j--) {
	    if (direntry->extension[j] <= ' ' || direntry->extension[j] > 0x7f)
		return -2;
	    else if (s->downcase_short_names)
1476
		lfn->name[i + j] = qemu_tolower(direntry->extension[j]);
1477 1478 1479 1480 1481 1482
	    else
		lfn->name[i + j] = direntry->extension[j];
	}
    } else
	lfn->name[i + j + 1] = '\0';

T
ths 已提交
1483
    lfn->len = strlen((char*)lfn->name);
1484 1485

    return 0;
1486 1487
}

1488 1489
static inline uint32_t modified_fat_get(BDRVVVFATState* s,
	unsigned int cluster)
1490
{
1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515
    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)
1516
	return 0;
1517 1518

    for (i = 0; !was_modified && i < s->sectors_per_cluster; i++)
K
Kevin Wolf 已提交
1519
	was_modified = bdrv_is_allocated(s->qcow,
1520 1521 1522
		cluster2sector(s, cluster_num) + i, 1, &dummy);

    return was_modified;
1523 1524
}

1525
static const char* get_basename(const char* path)
1526
{
1527 1528 1529 1530 1531
    char* basename = strrchr(path, '/');
    if (basename == NULL)
	return path;
    else
	return basename + 1; /* strip '/' */
1532 1533
}

1534 1535 1536 1537 1538 1539 1540 1541 1542
/*
 * 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
1543
} used_t;
1544

1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555
/*
 * 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
1556
	direntry_t* direntry, const char* path)
1557
{
1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581
    /*
     * 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
1582
    mapping_t* mapping = NULL;
1583
    const char* basename2 = NULL;
1584

1585
    vvfat_close_current_file(s);
1586

1587 1588
    /* the root directory */
    if (cluster_num == 0)
1589 1590
	return 0;

1591 1592 1593
    /* write support */
    if (s->qcow) {
	basename2 = get_basename(path);
1594

1595 1596 1597
	mapping = find_mapping_for_cluster(s, cluster_num);

	if (mapping) {
B
bellard 已提交
1598 1599
	    const char* basename;

1600 1601 1602
	    assert(mapping->mode & MODE_DELETED);
	    mapping->mode &= ~MODE_DELETED;

B
bellard 已提交
1603
	    basename = get_basename(mapping->path);
1604 1605 1606 1607 1608

	    assert(mapping->mode & MODE_NORMAL);

	    /* rename */
	    if (strcmp(basename, basename2))
1609
		schedule_rename(s, cluster_num, g_strdup(path));
1610 1611
	} else if (is_file(direntry))
	    /* new file */
1612
	    schedule_new_file(s, g_strdup(path), cluster_num);
1613
	else {
1614
            abort();
1615 1616
	    return 0;
	}
1617 1618
    }

1619 1620 1621 1622 1623 1624 1625
    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);
1626

1627 1628 1629 1630 1631 1632 1633 1634

		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 */
1635
                        abort();
1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646
			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) {
1647
                        abort();
1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667
			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
1668 1669 1670 1671 1672 1673 1674 1675 1676 1677
                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;
                        }
                    }
                }
1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694
	    }
	}

	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;
    }
1695 1696
}

1697
/*
1698
 * This function looks at the modified data (qcow).
1699 1700 1701 1702 1703
 * 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)
1704
{
1705
    int ret = 0;
1706
    unsigned char* cluster = g_malloc(s->cluster_size);
A
Anthony Liguori 已提交
1707 1708
    direntry_t* direntries = (direntry_t*)cluster;
    mapping_t* mapping = find_mapping_for_cluster(s, cluster_num);
1709 1710 1711

    long_file_name lfn;
    int path_len = strlen(path);
K
Kevin Wolf 已提交
1712
    char path2[PATH_MAX + 1];
1713 1714

    assert(path_len < PATH_MAX); /* len was tested before! */
B
blueswir1 已提交
1715
    pstrcpy(path2, sizeof(path2), path);
1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728
    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))
1729
	    schedule_rename(s, cluster_num, g_strdup(path));
1730 1731
    } else
	/* new directory */
1732
	schedule_mkdir(s, cluster_num, g_strdup(path));
1733

1734 1735
    lfn_init(&lfn);
    do {
1736
	int i;
1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752
	int subret = 0;

	ret++;

	if (s->used_clusters[cluster_num] & USED_ANY) {
	    fprintf(stderr, "cluster %d used more than once\n", (int)cluster_num);
	    return 0;
	}
	s->used_clusters[cluster_num] = USED_DIRECTORY;

DLOG(fprintf(stderr, "read cluster %d (sector %d)\n", (int)cluster_num, (int)cluster2sector(s, cluster_num)));
	subret = vvfat_read(s->bs, cluster2sector(s, cluster_num), cluster,
		s->sectors_per_cluster);
	if (subret) {
	    fprintf(stderr, "Error fetching direntries\n");
	fail:
1753
            g_free(cluster);
1754 1755 1756 1757
	    return 0;
	}

	for (i = 0; i < 0x10 * s->sectors_per_cluster; i++) {
1758
	    int cluster_count = 0;
1759

1760
DLOG(fprintf(stderr, "check direntry %d:\n", i); print_direntry(direntries + i));
1761 1762 1763 1764 1765 1766 1767 1768
	    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;
1769
	    }
1770 1771 1772 1773 1774 1775 1776 1777 1778
	    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
1779 1780
		if (subret > 0 || !strcmp((char*)lfn.name, ".")
			|| !strcmp((char*)lfn.name, ".."))
1781 1782 1783 1784 1785 1786 1787 1788
		    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
1789 1790
            pstrcpy(path2 + path_len + 1, sizeof(path2) - path_len - 1,
                    (char*)lfn.name);
1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812

	    if (is_directory(direntries + i)) {
		if (begin_of_direntry(direntries + i) == 0) {
		    DLOG(fprintf(stderr, "invalid begin for directory: %s\n", path2); print_direntry(direntries + i));
		    goto fail;
		}
		cluster_count = check_directory_consistency(s,
			begin_of_direntry(direntries + i), path2);
		if (cluster_count == 0) {
		    DLOG(fprintf(stderr, "problem in directory %s:\n", path2); print_direntry(direntries + i));
		    goto fail;
		}
	    } else if (is_file(direntries + i)) {
		/* check file size with FAT */
		cluster_count = get_cluster_count_for_direntry(s, direntries + i, path2);
		if (cluster_count !=
			(le32_to_cpu(direntries[i].size) + s->cluster_size
			 - 1) / s->cluster_size) {
		    DLOG(fprintf(stderr, "Cluster count mismatch\n"));
		    goto fail;
		}
	    } else
1813
                abort(); /* cluster_count = 0; */
1814 1815

	    ret += cluster_count;
1816 1817
	}

1818 1819
	cluster_num = modified_fat_get(s, cluster_num);
    } while(!fat_eof(s, cluster_num));
1820

1821
    g_free(cluster);
1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846
    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;
1847
	s->fat2 = g_malloc(size);
1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865
	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
1866
	    mapping_t* mapping = array_get(&(s->mapping), i);
1867 1868
	    if (mapping->first_mapping_index < 0)
		mapping->mode |= MODE_DELETED;
1869
	}
1870 1871 1872 1873 1874

    used_clusters_count = check_directory_consistency(s, 0, s->path);
    if (used_clusters_count <= 0) {
	DLOG(fprintf(stderr, "problem in directory\n"));
	return 0;
1875 1876
    }

1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905
    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
1906
	mapping_t* mapping = array_get(&(s->mapping), i);
1907 1908 1909 1910 1911 1912 1913 1914

#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);
1915
    }
1916 1917 1918
}

/* insert or update mapping */
A
Anthony Liguori 已提交
1919
static mapping_t* insert_mapping(BDRVVVFATState* s,
1920 1921 1922 1923 1924 1925 1926 1927 1928 1929
	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
1930 1931
    mapping_t* mapping = NULL;
    mapping_t* first_mapping = array_get(&(s->mapping), 0);
1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946

    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;
1947

A
Anthony Liguori 已提交
1948
DLOG(mapping_t* next_mapping;
1949 1950 1951 1952
assert(index + 1 >= s->mapping.next ||
((next_mapping = array_get(&(s->mapping), index + 1)) &&
 next_mapping->begin >= end)));

A
Anthony Liguori 已提交
1953
    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
1954 1955 1956 1957 1958 1959 1960 1961
	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
1962 1963
    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
    mapping_t* first_mapping = array_get(&(s->mapping), 0);
1964 1965

    /* free mapping */
1966 1967 1968
    if (mapping->first_mapping_index < 0) {
        g_free(mapping->path);
    }
1969 1970 1971 1972 1973 1974 1975

    /* 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
1976
    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
1977 1978
	s->current_mapping = array_get(&(s->mapping),
		s->current_mapping - first_mapping);
1979 1980 1981 1982

    return 0;
}

1983 1984 1985 1986
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
1987
	mapping_t* mapping = array_get(&(s->mapping), i);
1988 1989 1990 1991 1992 1993 1994
	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;
    }
}
1995

A
Anthony Liguori 已提交
1996
static direntry_t* insert_direntries(BDRVVVFATState* s,
1997
	int dir_index, int count)
1998
{
1999 2000 2001 2002
    /*
     * make room in s->directory,
     * adjust_dirindices
     */
A
Anthony Liguori 已提交
2003
    direntry_t* result = array_insert(&(s->directory), dir_index, count);
2004 2005 2006
    if (result == NULL)
	return NULL;
    adjust_dirindices(s, dir_index, count);
2007 2008 2009
    return result;
}

2010 2011 2012 2013 2014 2015 2016 2017
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;
}
2018

2019 2020 2021 2022 2023 2024 2025 2026
/*
 * 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)
2027
{
A
Anthony Liguori 已提交
2028 2029
    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
    direntry_t* direntry = array_get(&(s->directory), dir_index);
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
    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
2061
	    mapping_t* next_mapping = i >= s->mapping.next ? NULL :
2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074
		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;
2075
	    next_mapping->first_mapping_index =
2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094
		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;
	}
2095

2096 2097
	cluster = c1;
    }
2098 2099 2100 2101

    return 0;
}

2102 2103
static int commit_direntries(BDRVVVFATState* s,
	int dir_index, int parent_mapping_index)
2104
{
A
Anthony Liguori 已提交
2105
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2106
    uint32_t first_cluster = dir_index == 0 ? 0 : begin_of_direntry(direntry);
A
Anthony Liguori 已提交
2107
    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133

    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++;
2134

2135 2136 2137 2138
	for (new_cluster_count = 0, c = first_cluster; !fat_eof(s, c);
		c = modified_fat_get(s, c))
	    new_cluster_count++;
    }
2139

2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158
    if (new_cluster_count > old_cluster_count) {
	if (insert_direntries(s,
		current_dir_index + factor * old_cluster_count,
		factor * (new_cluster_count - old_cluster_count)) == NULL)
	    return -1;
    } else if (new_cluster_count < old_cluster_count)
	remove_direntries(s,
		current_dir_index + factor * new_cluster_count,
		factor * (old_cluster_count - new_cluster_count));

    for (c = first_cluster; !fat_eof(s, c); c = modified_fat_get(s, c)) {
	void* direntry = array_get(&(s->directory), current_dir_index);
	int ret = vvfat_read(s->bs, cluster2sector(s, c), direntry,
		s->sectors_per_cluster);
	if (ret)
	    return ret;
	assert(!strncmp(s->directory.pointer, "QEMU", 4));
	current_dir_index += factor;
    }
2159

2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175
    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;
	}
    }
2176

2177 2178
    return 0;
}
2179

2180 2181 2182 2183 2184
/* 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
2185
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2186 2187
    uint32_t c = begin_of_direntry(direntry);
    uint32_t first_cluster = c;
A
Anthony Liguori 已提交
2188
    mapping_t* mapping = find_mapping_for_cluster(s, c);
2189
    uint32_t size = filesize_of_direntry(direntry);
2190
    char* cluster = g_malloc(s->cluster_size);
2191 2192 2193 2194 2195 2196 2197 2198 2199
    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);

B
bellard 已提交
2200
    fd = open(mapping->path, O_RDWR | O_CREAT | O_BINARY, 0666);
2201 2202 2203
    if (fd < 0) {
	fprintf(stderr, "Could not open %s... (%s, %d)\n", mapping->path,
		strerror(errno), errno);
2204
        g_free(cluster);
2205
	return fd;
2206
    }
2207 2208 2209 2210 2211 2212
    if (offset > 0) {
        if (lseek(fd, offset, SEEK_SET) != offset) {
            g_free(cluster);
            return -3;
        }
    }
2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225

    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
2226
	    (uint8_t*)cluster, (rest_size + 0x1ff) / 0x200);
2227

2228 2229 2230 2231
        if (ret < 0) {
            g_free(cluster);
            return ret;
        }
2232

2233 2234 2235 2236
        if (write(fd, cluster, rest_size) < 0) {
            g_free(cluster);
            return -2;
        }
2237 2238 2239 2240 2241

	offset += rest_size;
	c = c1;
    }

2242 2243 2244
    if (ftruncate(fd, size)) {
        perror("ftruncate()");
        close(fd);
2245
        g_free(cluster);
2246 2247
        return -4;
    }
2248
    close(fd);
2249
    g_free(cluster);
2250 2251 2252 2253 2254 2255 2256 2257 2258 2259

    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
2260
	mapping_t* mapping = array_get(&(s->mapping), i);
2261 2262 2263 2264 2265
	if (mapping->mode & MODE_DELETED) {
	    fprintf(stderr, "deleted\n");
	    continue;
	}
	assert(mapping->dir_index < s->directory.next);
A
Anthony Liguori 已提交
2266
	direntry_t* direntry = array_get(&(s->directory), mapping->dir_index);
2267 2268 2269 2270
	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);
2271 2272 2273 2274
	}
    }
}

2275 2276
/* test, if all direntries have mappings */
static void check2(BDRVVVFATState* s)
2277 2278
{
    int i;
2279
    int first_mapping = -1;
2280

2281
    for (i = 0; i < s->directory.next; i++) {
A
Anthony Liguori 已提交
2282
	direntry_t* direntry = array_get(&(s->directory), i);
2283

2284
	if (is_short_name(direntry) && begin_of_direntry(direntry)) {
A
Anthony Liguori 已提交
2285
	    mapping_t* mapping = find_mapping_for_cluster(s, begin_of_direntry(direntry));
2286 2287 2288 2289
	    assert(mapping);
	    assert(mapping->dir_index == i || is_dot(direntry));
	    assert(mapping->begin == begin_of_direntry(direntry) || is_dot(direntry));
	}
2290

2291 2292 2293
	if ((i % (0x10 * s->sectors_per_cluster)) == 0) {
	    /* cluster start */
	    int j, count = 0;
2294

2295
	    for (j = 0; j < s->mapping.next; j++) {
A
Anthony Liguori 已提交
2296
		mapping_t* mapping = array_get(&(s->mapping), j);
2297
		if (mapping->mode & MODE_DELETED)
2298
		    continue;
2299 2300 2301 2302 2303 2304 2305 2306 2307 2308
		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
2309
			    mapping_t* parent = array_get(&(s->mapping), mapping->info.dir.parent_mapping_index);
2310 2311 2312 2313
			    assert(parent->mode & MODE_DIRECTORY);
			    assert(parent->info.dir.first_dir_index < mapping->info.dir.first_dir_index);
			}
		    }
2314
		}
2315 2316 2317 2318 2319 2320 2321
	    }
	    if (count == 0)
		first_mapping = -1;
	}
    }
}
#endif
2322

2323 2324 2325
static int handle_renames_and_mkdirs(BDRVVVFATState* s)
{
    int i;
2326

2327 2328 2329
#ifdef DEBUG
    fprintf(stderr, "handle_renames\n");
    for (i = 0; i < s->commits.next; i++) {
A
Anthony Liguori 已提交
2330
	commit_t* commit = array_get(&(s->commits), i);
2331 2332 2333 2334 2335
	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
2336
	commit_t* commit = array_get(&(s->commits), i);
2337
	if (commit->action == ACTION_RENAME) {
A
Anthony Liguori 已提交
2338
	    mapping_t* mapping = find_mapping_for_cluster(s,
2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350
		    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
2351
		direntry_t* direntry = array_get(&(s->directory),
2352 2353 2354 2355 2356 2357 2358
			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
2359
			direntry_t* d = direntry + i;
2360 2361

			if (is_file(d) || (is_directory(d) && !is_dot(d))) {
A
Anthony Liguori 已提交
2362
			    mapping_t* m = find_mapping_for_cluster(s,
2363 2364
				    begin_of_direntry(d));
			    int l = strlen(m->path);
2365
			    char* new_path = g_malloc(l + diff + 1);
2366 2367 2368

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

B
blueswir1 已提交
2369 2370 2371
                            pstrcpy(new_path, l + diff + 1, mapping->path);
                            pstrcpy(new_path + l1, l + diff + 1 - l1,
                                    m->path + l2);
2372 2373

			    schedule_rename(s, m->begin, new_path);
2374
			}
2375 2376 2377
			i++;
		    } while((i % (0x10 * s->sectors_per_cluster)) != 0);
		    c = fat_get(s, c);
2378 2379 2380
		}
	    }

2381
            g_free(old_path);
2382 2383 2384
	    array_remove(&(s->commits), i);
	    continue;
	} else if (commit->action == ACTION_MKDIR) {
A
Anthony Liguori 已提交
2385
	    mapping_t* mapping;
2386 2387
	    int j, parent_path_len;

B
bellard 已提交
2388 2389 2390 2391 2392 2393 2394
#ifdef __MINGW32__
            if (mkdir(commit->path))
                return -5;
#else
            if (mkdir(commit->path, 0755))
                return -5;
#endif
2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412

	    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
2413
		mapping_t* m = array_get(&(s->mapping), j);
2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440
		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
2441
	commit_t* commit = array_get(&(s->commits), i);
2442 2443
	switch(commit->action) {
	case ACTION_RENAME: case ACTION_MKDIR:
2444
            abort();
2445 2446 2447
	    fail = -2;
	    break;
	case ACTION_WRITEOUT: {
B
Blue Swirl 已提交
2448 2449
#ifndef NDEBUG
            /* these variables are only used by assert() below */
A
Anthony Liguori 已提交
2450
	    direntry_t* entry = array_get(&(s->directory),
2451 2452
		    commit->param.writeout.dir_index);
	    uint32_t begin = begin_of_direntry(entry);
A
Anthony Liguori 已提交
2453
	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
B
Blue Swirl 已提交
2454
#endif
2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467

	    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
2468 2469
	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
	    direntry_t* entry;
2470
	    int i;
2471

2472 2473 2474 2475 2476
	    /* 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;
2477 2478
	    }

2479 2480 2481 2482
	    if (i >= s->directory.next) {
		fail = -6;
		continue;
	    }
2483

2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504
	    /* 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:
2505
            abort();
2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523
	}
    }
    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
2524
	    mapping_t* mapping = array_get(&(s->mapping), i);
2525
	    if (mapping->mode & MODE_DELETED) {
A
Anthony Liguori 已提交
2526
		direntry_t* entry = array_get(&(s->directory),
2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540
			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;
2541
			}
2542 2543

			for (j = 1; j < s->mapping.next; j++) {
A
Anthony Liguori 已提交
2544
			    mapping_t* m = array_get(&(s->mapping), j);
2545 2546 2547 2548 2549 2550 2551
			    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;
2552
			}
2553 2554
			remove_direntries(s, first_dir_index,
				next_dir_index - first_dir_index);
2555

2556
			deleted++;
2557
		    }
2558 2559 2560 2561
		} else {
		    if (unlink(mapping->path))
			return -4;
		    deleted++;
2562
		}
2563 2564
		DLOG(fprintf(stderr, "DELETE (%d)\n", i); print_mapping(mapping); print_direntry(entry));
		remove_mapping(s, i);
2565 2566 2567
	    }
	}
    }
2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592

    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);
2593
        abort();
2594 2595 2596
	return ret;
    }

2597
    /* copy FAT (with bdrv_read) */
2598 2599 2600 2601 2602 2603
    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);
2604
        abort();
2605 2606 2607 2608 2609 2610
	return ret;
    }

    ret = handle_commits(s);
    if (ret) {
	fprintf(stderr, "Error handling commits (%d)\n", ret);
2611
        abort();
2612 2613 2614 2615 2616 2617
	return ret;
    }

    ret = handle_deletes(s);
    if (ret) {
	fprintf(stderr, "Error deleting\n");
2618
        abort();
2619 2620 2621
	return ret;
    }

K
Kevin Wolf 已提交
2622 2623 2624
    if (s->qcow->drv->bdrv_make_empty) {
        s->qcow->drv->bdrv_make_empty(s->qcow);
    }
2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640

    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);
}

2641
static int vvfat_write(BlockDriverState *bs, int64_t sector_num,
2642 2643
                    const uint8_t *buf, int nb_sectors)
{
2644
    BDRVVVFATState *s = bs->opaque;
2645 2646 2647 2648
    int i, ret;

DLOG(checkpoint());

2649 2650 2651 2652 2653
    /* Check if we're operating in read-only mode */
    if (s->qcow == NULL) {
        return -EACCES;
    }

2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666
    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
2667
	mapping_t* mapping = find_mapping_for_cluster(s, i);
2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678
	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
2679
		const direntry_t* direntries;
2680 2681 2682 2683 2684 2685 2686 2687
		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;
2688
		dir_index  = mapping->dir_index +
2689
		    0x10 * (begin - mapping->begin * s->sectors_per_cluster);
A
Anthony Liguori 已提交
2690
		direntries = (direntry_t*)(buf + 0x200 * (begin - sector_num));
2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702

		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
2703
				    sizeof(direntry_t))) {
2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718
			    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
2719
    ret = bdrv_write(s->qcow, sector_num, buf, nb_sectors);
2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737
    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;
}

2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748
static coroutine_fn int vvfat_co_write(BlockDriverState *bs, int64_t sector_num,
                                       const uint8_t *buf, int nb_sectors)
{
    int ret;
    BDRVVVFATState *s = bs->opaque;
    qemu_co_mutex_lock(&s->lock);
    ret = vvfat_write(bs, sector_num, buf, nb_sectors);
    qemu_co_mutex_unlock(&s->lock);
    return ret;
}

2749 2750 2751 2752 2753 2754 2755 2756 2757
static int vvfat_is_allocated(BlockDriverState *bs,
	int64_t sector_num, int nb_sectors, int* n)
{
    BDRVVVFATState* s = bs->opaque;
    *n = s->sector_count - sector_num;
    if (*n > nb_sectors)
	*n = nb_sectors;
    else if (*n < 0)
	return 0;
2758
    return 1;
2759 2760 2761 2762
}

static int write_target_commit(BlockDriverState *bs, int64_t sector_num,
	const uint8_t* buffer, int nb_sectors) {
2763
    BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
2764 2765 2766 2767
    return try_commit(s);
}

static void write_target_close(BlockDriverState *bs) {
2768
    BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
2769
    bdrv_delete(s->qcow);
2770
    g_free(s->qcow_filename);
2771 2772 2773
}

static BlockDriver vvfat_write_target = {
2774 2775 2776
    .format_name        = "vvfat_write_target",
    .bdrv_write         = write_target_commit,
    .bdrv_close         = write_target_close,
2777 2778 2779 2780
};

static int enable_write_target(BDRVVVFATState *s)
{
K
Kevin Wolf 已提交
2781 2782
    BlockDriver *bdrv_qcow;
    QEMUOptionParameter *options;
K
Kevin Wolf 已提交
2783
    int ret;
2784 2785 2786
    int size = sector2cluster(s, s->sector_count);
    s->used_clusters = calloc(size, 1);

A
Anthony Liguori 已提交
2787
    array_init(&(s->commits), sizeof(commit_t));
2788

2789
    s->qcow_filename = g_malloc(1024);
B
bellard 已提交
2790
    get_tmp_filename(s->qcow_filename, 1024);
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    bdrv_qcow = bdrv_find_format("qcow");
    options = parse_option_parameters("", bdrv_qcow->create_options, NULL);
    set_option_parameter_int(options, BLOCK_OPT_SIZE, s->sector_count * 512);
    set_option_parameter(options, BLOCK_OPT_BACKING_FILE, "fat:");

    if (bdrv_create(bdrv_qcow, s->qcow_filename, options) < 0)
2798
	return -1;
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2800
    s->qcow = bdrv_new("");
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    if (s->qcow == NULL) {
        return -1;
    }

    ret = bdrv_open(s->qcow, s->qcow_filename,
            BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, bdrv_qcow);
    if (ret < 0) {
	return ret;
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    }
2810 2811 2812 2813 2814 2815 2816

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

    s->bs->backing_hd = calloc(sizeof(BlockDriverState), 1);
    s->bs->backing_hd->drv = &vvfat_write_target;
2817
    s->bs->backing_hd->opaque = g_malloc(sizeof(void*));
2818
    *(void**)s->bs->backing_hd->opaque = s;
2819

2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830
    return 0;
}

static void vvfat_close(BlockDriverState *bs)
{
    BDRVVVFATState *s = bs->opaque;

    vvfat_close_current_file(s);
    array_free(&(s->fat));
    array_free(&(s->directory));
    array_free(&(s->mapping));
2831
    g_free(s->cluster_buffer);
2832 2833
}

2834
static BlockDriver bdrv_vvfat = {
2835 2836
    .format_name	= "vvfat",
    .instance_size	= sizeof(BDRVVVFATState),
2837
    .bdrv_file_open	= vvfat_open,
2838
    .bdrv_read          = vvfat_co_read,
2839
    .bdrv_write         = vvfat_co_write,
2840 2841 2842
    .bdrv_close		= vvfat_close,
    .bdrv_is_allocated	= vvfat_is_allocated,
    .protocol_name	= "fat",
2843 2844
};

2845 2846 2847 2848 2849 2850 2851
static void bdrv_vvfat_init(void)
{
    bdrv_register(&bdrv_vvfat);
}

block_init(bdrv_vvfat_init);

2852
#ifdef DEBUG
2853
static void checkpoint(void) {
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    assert(((mapping_t*)array_get(&(vvv->mapping), 0))->end == 2);
2855 2856 2857 2858
    check1(vvv);
    check2(vvv);
    assert(!vvv->current_mapping || vvv->current_fd || (vvv->current_mapping->mode & MODE_DIRECTORY));
#if 0
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    if (((direntry_t*)vvv->directory.pointer)[1].attributes != 0xf)
2860
	fprintf(stderr, "Nonono!\n");
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    mapping_t* mapping;
    direntry_t* direntry;
2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873
    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