vvfat.c 79.7 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! */
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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
766
	    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
    }

796 797 798 799 800 801 802
/* TODO: if there are more entries, bootsector has to be adjusted! */
#define ROOT_ENTRIES (0x02 * 0x10 * s->sectors_per_cluster)
    if (mapping_index == 0 && s->directory.next < ROOT_ENTRIES) {
	/* root directory */
	int cur = s->directory.next;
	array_ensure_allocated(&(s->directory), ROOT_ENTRIES - 1);
	memset(array_get(&(s->directory), cur), 0,
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Anthony Liguori 已提交
803
		(ROOT_ENTRIES - cur) * sizeof(direntry_t));
804
    }
805

806
     /* reget the mapping, since s->mapping was possibly realloc()ed */
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Anthony Liguori 已提交
807
    mapping = (mapping_t*)array_get(&(s->mapping), mapping_index);
808 809 810 811
    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
812
    direntry = (direntry_t*)array_get(&(s->directory), mapping->dir_index);
813
    set_begin_of_direntry(direntry, mapping->begin);
814

815 816
    return 0;
}
817

818 819 820 821
static inline uint32_t sector2cluster(BDRVVVFATState* s,off_t sector_num)
{
    return (sector_num-s->faked_sectors)/s->sectors_per_cluster;
}
822

823 824 825 826
static inline off_t cluster2sector(BDRVVVFATState* s, uint32_t cluster_num)
{
    return s->faked_sectors + s->sectors_per_cluster * cluster_num;
}
827

828 829
static int init_directories(BDRVVVFATState* s,
	const char* dirname)
830
{
A
Anthony Liguori 已提交
831 832
    bootsector_t* bootsector;
    mapping_t* mapping;
833 834 835 836 837 838
    unsigned int i;
    unsigned int cluster;

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

    s->cluster_size=s->sectors_per_cluster*0x200;
839
    s->cluster_buffer=g_malloc(s->cluster_size);
840 841 842 843 844 845 846 847 848 849

    /*
     * 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 */
850

A
Anthony Liguori 已提交
851 852
    array_init(&(s->mapping),sizeof(mapping_t));
    array_init(&(s->directory),sizeof(direntry_t));
853 854 855

    /* add volume label */
    {
A
Anthony Liguori 已提交
856
	direntry_t* entry=array_get_next(&(s->directory));
857
	entry->attributes=0x28; /* archive | volume label */
858 859
	memcpy(entry->name,"QEMU VVF",8);
	memcpy(entry->extension,"AT ",3);
860 861 862 863 864
    }

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

865 866 867 868 869 870 871 872
    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;
873
    mapping->path = g_strdup(dirname);
874 875 876 877 878 879 880 881
    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++) {
882
	/* MS-DOS expects the FAT to be 0 for the root directory
883 884 885 886 887 888 889 890 891 892
	 * (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);
893 894
		return -1;
	    }
895 896 897
	    mapping = array_get(&(s->mapping), i);
	} else {
	    assert(mapping->mode == MODE_UNDEFINED);
898
	    mapping->mode=MODE_NORMAL;
899 900
	    mapping->begin = cluster;
	    if (mapping->end > 0) {
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Anthony Liguori 已提交
901
		direntry_t* direntry = array_get(&(s->directory),
902 903 904 905 906 907 908
			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;
909
	    }
910 911 912 913
	}

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

914 915 916 917 918 919 920 921 922 923 924 925
	/* next free cluster */
	cluster = mapping->end;

	if(cluster > s->cluster_count) {
	    fprintf(stderr,"Directory does not fit in FAT%d (capacity %s)\n",
		    s->fat_type,
		    s->fat_type == 12 ? s->sector_count == 2880 ? "1.44 MB"
								: "2.88 MB"
				      : "504MB");
	    return -EINVAL;
	}

926 927
	/* fix fat for entry */
	if (fix_fat) {
928
	    int j;
929 930 931 932
	    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);
	}
933 934
    }

935 936 937 938 939 940 941
    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);
942

943 944
    s->current_mapping = NULL;

A
Anthony Liguori 已提交
945
    bootsector=(bootsector_t*)(s->first_sectors+(s->first_sectors_number-1)*0x200);
946 947 948 949 950 951 952 953 954
    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);
955 956 957
    bootsector->total_sectors16=s->sector_count>0xffff?0:cpu_to_le16(s->sector_count);
    bootsector->media_type=(s->fat_type!=12?0xf8:s->sector_count==5760?0xf9:0xf8); /* media descriptor */
    s->fat.pointer[0] = bootsector->media_type;
958
    bootsector->sectors_per_fat=cpu_to_le16(s->sectors_per_fat);
959 960
    bootsector->sectors_per_track=cpu_to_le16(s->bs->secs);
    bootsector->number_of_heads=cpu_to_le16(s->bs->heads);
961
    bootsector->hidden_sectors=cpu_to_le32(s->first_sectors_number==1?0:0x3f);
962
    bootsector->total_sectors=cpu_to_le32(s->sector_count>0xffff?s->sector_count:0);
963

964 965
    /* LATER TODO: if FAT32, this is wrong */
    bootsector->u.fat16.drive_number=s->fat_type==12?0:0x80; /* assume this is hda (TODO) */
966 967 968 969 970 971 972 973 974 975 976
    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
977
#ifdef DEBUG
978
static BDRVVVFATState *vvv = NULL;
B
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979
#endif
980 981 982 983

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

B
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984
static int vvfat_open(BlockDriverState *bs, const char* dirname, int flags)
985 986
{
    BDRVVVFATState *s = bs->opaque;
987
    int floppy = 0;
988 989
    int i;

B
bellard 已提交
990
#ifdef DEBUG
991
    vvv = s;
B
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992
#endif
993 994 995 996 997 998 999 1000

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

    s->bs = bs;

1001
    s->fat_type=16;
1002 1003
    /* LATER TODO: if FAT32, adjust */
    s->sectors_per_cluster=0x10;
T
ths 已提交
1004 1005
    /* 504MB disk*/
    bs->cyls=1024; bs->heads=16; bs->secs=63;
1006 1007 1008 1009

    s->current_cluster=0xffffffff;

    s->first_sectors_number=0x40;
1010 1011 1012 1013 1014 1015
    /* 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;
1016

1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027
    if (!strstart(dirname, "fat:", NULL))
	return -1;

    if (strstr(dirname, ":floppy:")) {
	floppy = 1;
	s->fat_type = 12;
	s->first_sectors_number = 1;
	s->sectors_per_cluster=2;
	bs->cyls = 80; bs->heads = 2; bs->secs = 36;
    }

T
ths 已提交
1028 1029
    s->sector_count=bs->cyls*bs->heads*bs->secs;

1030 1031 1032 1033 1034 1035 1036 1037
    if (strstr(dirname, ":32:")) {
	fprintf(stderr, "Big fat greek warning: FAT32 has not been tested. You are welcome to do so!\n");
	s->fat_type = 32;
    } else if (strstr(dirname, ":16:")) {
	s->fat_type = 16;
    } else if (strstr(dirname, ":12:")) {
	s->fat_type = 12;
	s->sector_count=2880;
1038
    }
1039

T
ths 已提交
1040 1041 1042 1043 1044 1045
    if (strstr(dirname, ":rw:")) {
	if (enable_write_target(s))
	    return -1;
	bs->read_only = 0;
    }

1046 1047
    i = strrchr(dirname, ':') - dirname;
    assert(i >= 3);
1048
    if (dirname[i-2] == ':' && qemu_isalpha(dirname[i-1]))
1049 1050 1051 1052 1053 1054
	/* 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
1055

1056
    if(init_directories(s, dirname))
1057 1058
	return -1;

T
ths 已提交
1059 1060
    s->sector_count = s->faked_sectors + s->sectors_per_cluster*s->cluster_count;

1061 1062 1063
    if(s->first_sectors_number==0x40)
	init_mbr(s);

1064 1065 1066 1067 1068
    /* for some reason or other, MS-DOS does not like to know about CHS... */
    if (floppy)
	bs->heads = bs->cyls = bs->secs = 0;

    //    assert(is_consistent(s));
1069
    qemu_co_mutex_init(&s->lock);
1070 1071 1072 1073 1074 1075
    return 0;
}

static inline void vvfat_close_current_file(BDRVVVFATState *s)
{
    if(s->current_mapping) {
1076 1077 1078 1079 1080
	s->current_mapping = NULL;
	if (s->current_fd) {
		close(s->current_fd);
		s->current_fd = 0;
	}
1081
    }
1082
    s->current_cluster = -1;
1083 1084 1085 1086 1087 1088 1089 1090
}

/* 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) {
1091
        int index3;
A
Anthony Liguori 已提交
1092
	mapping_t* mapping;
1093 1094
	index3=(index1+index2)/2;
	mapping=array_get(&(s->mapping),index3);
1095 1096
	assert(mapping->begin < mapping->end);
	if(mapping->begin>=cluster_num) {
1097 1098
	    assert(index2!=index3 || index2==0);
	    if(index2==index3)
1099
		return index1;
1100 1101 1102
	    index2=index3;
	} else {
	    if(index1==index3)
1103
		return mapping->end<=cluster_num ? index2 : index1;
1104 1105 1106
	    index1=index3;
	}
	assert(index1<=index2);
1107 1108
	DLOG(mapping=array_get(&(s->mapping),index1);
	assert(mapping->begin<=cluster_num);
1109
	assert(index2 >= s->mapping.next ||
1110 1111
		((mapping = array_get(&(s->mapping),index2)) &&
		mapping->end>cluster_num)));
1112 1113 1114
    }
}

A
Anthony Liguori 已提交
1115
static inline mapping_t* find_mapping_for_cluster(BDRVVVFATState* s,int cluster_num)
1116 1117
{
    int index=find_mapping_for_cluster_aux(s,cluster_num,0,s->mapping.next);
A
Anthony Liguori 已提交
1118
    mapping_t* mapping;
1119
    if(index>=s->mapping.next)
1120
        return NULL;
1121 1122
    mapping=array_get(&(s->mapping),index);
    if(mapping->begin>cluster_num)
1123
        return NULL;
1124
    assert(mapping->begin<=cluster_num && mapping->end>cluster_num);
1125 1126 1127
    return mapping;
}

A
Anthony Liguori 已提交
1128
static int open_file(BDRVVVFATState* s,mapping_t* mapping)
1129 1130 1131 1132
{
    if(!mapping)
	return -1;
    if(!s->current_mapping ||
1133
	    strcmp(s->current_mapping->path,mapping->path)) {
1134
	/* open file */
1135
	int fd = open(mapping->path, O_RDONLY | O_BINARY | O_LARGEFILE);
1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149
	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;
1150
	assert(!s->current_mapping || s->current_fd || (s->current_mapping->mode & MODE_DIRECTORY));
1151 1152 1153 1154
	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
1155
	    mapping_t* mapping=find_mapping_for_cluster(s,cluster_num);
1156 1157 1158 1159 1160 1161 1162 1163

	    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
1164
		s->cluster = (unsigned char*)s->directory.pointer+offset
1165 1166 1167 1168 1169 1170 1171 1172
			+ 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))
1173
		return -2;
1174 1175
	} else if (s->current_mapping->mode & MODE_DIRECTORY)
	    goto read_cluster_directory;
1176

1177 1178 1179
	assert(s->current_fd);

	offset=s->cluster_size*(cluster_num-s->current_mapping->begin)+s->current_mapping->info.file.offset;
1180 1181
	if(lseek(s->current_fd, offset, SEEK_SET)!=offset)
	    return -3;
1182
	s->cluster=s->cluster_buffer;
1183 1184 1185 1186 1187 1188 1189 1190 1191 1192
	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;
}

1193
#ifdef DEBUG
A
Anthony Liguori 已提交
1194
static void print_direntry(const direntry_t* direntry)
1195
{
1196 1197 1198
    int j = 0;
    char buffer[1024];

K
Kevin Wolf 已提交
1199
    fprintf(stderr, "direntry %p: ", direntry);
1200 1201
    if(!direntry)
	return;
1202
    if(is_long_name(direntry)) {
1203 1204 1205
	unsigned char* c=(unsigned char*)direntry;
	int i;
	for(i=1;i<11 && c[i] && c[i]!=0xff;i+=2)
1206
#define ADD_CHAR(c) {buffer[j] = (c); if (buffer[j] < ' ') buffer[j] = 0xb0; j++;}
1207
	    ADD_CHAR(c[i]);
1208
	for(i=14;i<26 && c[i] && c[i]!=0xff;i+=2)
1209
	    ADD_CHAR(c[i]);
1210
	for(i=28;i<32 && c[i] && c[i]!=0xff;i+=2)
1211 1212 1213
	    ADD_CHAR(c[i]);
	buffer[j] = 0;
	fprintf(stderr, "%s\n", buffer);
1214 1215 1216
    } else {
	int i;
	for(i=0;i<11;i++)
1217 1218 1219 1220
	    ADD_CHAR(direntry->name[i]);
	buffer[j] = 0;
	fprintf(stderr,"%s attributes=0x%02x begin=%d size=%d\n",
		buffer,
1221
		direntry->attributes,
1222
		begin_of_direntry(direntry),le32_to_cpu(direntry->size));
1223 1224 1225
    }
}

A
Anthony Liguori 已提交
1226
static void print_mapping(const mapping_t* mapping)
1227
{
K
Kevin Wolf 已提交
1228 1229 1230 1231 1232
    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);

1233 1234 1235 1236
    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);
1237
}
1238
#endif
1239

1240
static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
1241
                    uint8_t *buf, int nb_sectors)
1242
{
1243
    BDRVVVFATState *s = bs->opaque;
1244 1245
    int i;

1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260
    for(i=0;i<nb_sectors;i++,sector_num++) {
	if (sector_num >= s->sector_count)
	   return -1;
	if (s->qcow) {
	    int n;
	    if (s->qcow->drv->bdrv_is_allocated(s->qcow,
			sector_num, nb_sectors-i, &n)) {
DLOG(fprintf(stderr, "sectors %d+%d allocated\n", (int)sector_num, n));
		if (s->qcow->drv->bdrv_read(s->qcow, sector_num, buf+i*0x200, n))
		    return -1;
		i += n - 1;
		sector_num += n - 1;
		continue;
	    }
DLOG(fprintf(stderr, "sector %d not allocated\n", (int)sector_num));
1261
	}
1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276
	if(sector_num<s->faked_sectors) {
	    if(sector_num<s->first_sectors_number)
		memcpy(buf+i*0x200,&(s->first_sectors[sector_num*0x200]),0x200);
	    else if(sector_num-s->first_sectors_number<s->sectors_per_fat)
		memcpy(buf+i*0x200,&(s->fat.pointer[(sector_num-s->first_sectors_number)*0x200]),0x200);
	    else if(sector_num-s->first_sectors_number-s->sectors_per_fat<s->sectors_per_fat)
		memcpy(buf+i*0x200,&(s->fat.pointer[(sector_num-s->first_sectors_number-s->sectors_per_fat)*0x200]),0x200);
	} else {
	    uint32_t sector=sector_num-s->faked_sectors,
	    sector_offset_in_cluster=(sector%s->sectors_per_cluster),
	    cluster_num=sector/s->sectors_per_cluster;
	    if(read_cluster(s, cluster_num) != 0) {
		/* LATER TODO: strict: return -1; */
		memset(buf+i*0x200,0,0x200);
		continue;
1277
	    }
1278
	    memcpy(buf+i*0x200,s->cluster+sector_offset_in_cluster*0x200,0x200);
1279 1280 1281 1282 1283
	}
    }
    return 0;
}

1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294
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;
}

1295
/* LATER TODO: statify all functions */
1296

1297 1298
/*
 * Idea of the write support (use snapshot):
1299
 *
1300 1301
 * 1. check if all data is consistent, recording renames, modifications,
 *    new files and directories (in s->commits).
1302
 *
1303
 * 2. if the data is not consistent, stop committing
1304
 *
1305 1306
 * 3. handle renames, and create new files and directories (do not yet
 *    write their contents)
1307
 *
1308 1309
 * 4. walk the directories, fixing the mapping and direntries, and marking
 *    the handled mappings as not deleted
1310
 *
1311
 * 5. commit the contents of the files
1312
 *
1313
 * 6. handle deleted files and directories
1314 1315 1316
 *
 */

A
Anthony Liguori 已提交
1317
typedef struct commit_t {
1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328
    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
1329
} commit_t;
1330

1331
static void clear_commits(BDRVVVFATState* s)
1332 1333
{
    int i;
1334 1335
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
1336
	commit_t* commit = array_get(&(s->commits), i);
1337 1338 1339
	assert(commit->path || commit->action == ACTION_WRITEOUT);
	if (commit->action != ACTION_WRITEOUT) {
	    assert(commit->path);
1340
            g_free(commit->path);
1341 1342
	} else
	    assert(commit->path == NULL);
1343
    }
1344
    s->commits.next = 0;
1345 1346
}

1347 1348
static void schedule_rename(BDRVVVFATState* s,
	uint32_t cluster, char* new_path)
1349
{
A
Anthony Liguori 已提交
1350
    commit_t* commit = array_get_next(&(s->commits));
1351 1352 1353
    commit->path = new_path;
    commit->param.rename.cluster = cluster;
    commit->action = ACTION_RENAME;
1354 1355
}

1356 1357
static void schedule_writeout(BDRVVVFATState* s,
	int dir_index, uint32_t modified_offset)
1358
{
A
Anthony Liguori 已提交
1359
    commit_t* commit = array_get_next(&(s->commits));
1360 1361 1362 1363
    commit->path = NULL;
    commit->param.writeout.dir_index = dir_index;
    commit->param.writeout.modified_offset = modified_offset;
    commit->action = ACTION_WRITEOUT;
1364 1365
}

1366 1367
static void schedule_new_file(BDRVVVFATState* s,
	char* path, uint32_t first_cluster)
1368
{
A
Anthony Liguori 已提交
1369
    commit_t* commit = array_get_next(&(s->commits));
1370 1371 1372 1373 1374 1375 1376
    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
1377
    commit_t* commit = array_get_next(&(s->commits));
1378 1379 1380 1381 1382 1383
    commit->path = path;
    commit->param.mkdir.cluster = cluster;
    commit->action = ACTION_MKDIR;
}

typedef struct {
1384 1385 1386 1387 1388 1389
    /*
     * 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];
1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401
    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
1402
	const direntry_t* direntry)
1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413
{
    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
1414
	lfn->name[lfn->sequence_number * 13] = 0;
1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434
    } 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;
1435
    }
1436 1437

    if (pointer[0] & 0x40)
T
ths 已提交
1438
	lfn->len = offset + strlen((char*)lfn->name + offset);
1439

1440 1441 1442
    return 0;
}

1443 1444
/* 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
1445
	long_file_name* lfn, direntry_t* direntry)
1446
{
1447
    int i, j;
1448

1449 1450 1451 1452 1453 1454 1455 1456
    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)
1457
	    lfn->name[i] = qemu_tolower(direntry->name[i]);
1458 1459
	else
	    lfn->name[i] = direntry->name[i];
1460 1461
    }

1462 1463 1464 1465 1466 1467 1468 1469
    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)
1470
		lfn->name[i + j] = qemu_tolower(direntry->extension[j]);
1471 1472 1473 1474 1475 1476
	    else
		lfn->name[i + j] = direntry->extension[j];
	}
    } else
	lfn->name[i + j + 1] = '\0';

T
ths 已提交
1477
    lfn->len = strlen((char*)lfn->name);
1478 1479

    return 0;
1480 1481
}

1482 1483
static inline uint32_t modified_fat_get(BDRVVVFATState* s,
	unsigned int cluster)
1484
{
1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509
    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)
1510
	return 0;
1511 1512 1513 1514 1515 1516

    for (i = 0; !was_modified && i < s->sectors_per_cluster; i++)
	was_modified = s->qcow->drv->bdrv_is_allocated(s->qcow,
		cluster2sector(s, cluster_num) + i, 1, &dummy);

    return was_modified;
1517 1518
}

1519
static const char* get_basename(const char* path)
1520
{
1521 1522 1523 1524 1525
    char* basename = strrchr(path, '/');
    if (basename == NULL)
	return path;
    else
	return basename + 1; /* strip '/' */
1526 1527
}

1528 1529 1530 1531 1532 1533 1534 1535 1536
/*
 * 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
1537
} used_t;
1538

1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549
/*
 * 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
1550
	direntry_t* direntry, const char* path)
1551
{
1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
    /*
     * 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
1576
    mapping_t* mapping = NULL;
1577
    const char* basename2 = NULL;
1578

1579
    vvfat_close_current_file(s);
1580

1581 1582
    /* the root directory */
    if (cluster_num == 0)
1583 1584
	return 0;

1585 1586 1587
    /* write support */
    if (s->qcow) {
	basename2 = get_basename(path);
1588

1589 1590 1591
	mapping = find_mapping_for_cluster(s, cluster_num);

	if (mapping) {
B
bellard 已提交
1592 1593
	    const char* basename;

1594 1595 1596
	    assert(mapping->mode & MODE_DELETED);
	    mapping->mode &= ~MODE_DELETED;

B
bellard 已提交
1597
	    basename = get_basename(mapping->path);
1598 1599 1600 1601 1602

	    assert(mapping->mode & MODE_NORMAL);

	    /* rename */
	    if (strcmp(basename, basename2))
1603
		schedule_rename(s, cluster_num, g_strdup(path));
1604 1605
	} else if (is_file(direntry))
	    /* new file */
1606
	    schedule_new_file(s, g_strdup(path), cluster_num);
1607
	else {
1608
            abort();
1609 1610
	    return 0;
	}
1611 1612
    }

1613 1614 1615 1616 1617 1618 1619
    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);
1620

1621 1622 1623 1624 1625 1626 1627 1628

		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 */
1629
                        abort();
1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640
			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) {
1641
                        abort();
1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688
			copy_it = 1;
		    }

		    /* need to write out? */
		    if (!was_modified && is_file(direntry)) {
			was_modified = 1;
			schedule_writeout(s, mapping->dir_index, offset);
		    }
		}
	    }

	    if (copy_it) {
		int i, dummy;
		/*
		 * This is horribly inefficient, but that is okay, since
		 * it is rarely executed, if at all.
		 */
		int64_t offset = cluster2sector(s, cluster_num);

		vvfat_close_current_file(s);
		for (i = 0; i < s->sectors_per_cluster; i++)
		    if (!s->qcow->drv->bdrv_is_allocated(s->qcow,
				offset + i, 1, &dummy)) {
			if (vvfat_read(s->bs,
				    offset, s->cluster_buffer, 1))
			    return -1;
			if (s->qcow->drv->bdrv_write(s->qcow,
				    offset, s->cluster_buffer, 1))
			    return -2;
		    }
	    }
	}

	ret++;
	if (s->used_clusters[cluster_num] & USED_ANY)
	    return 0;
	s->used_clusters[cluster_num] = USED_FILE;

	cluster_num = modified_fat_get(s, cluster_num);

	if (fat_eof(s, cluster_num))
	    return ret;
	else if (cluster_num < 2 || cluster_num > s->max_fat_value - 16)
	    return -1;

	offset += s->cluster_size;
    }
1689 1690
}

1691
/*
1692
 * This function looks at the modified data (qcow).
1693 1694 1695 1696 1697
 * 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)
1698
{
1699
    int ret = 0;
1700
    unsigned char* cluster = g_malloc(s->cluster_size);
A
Anthony Liguori 已提交
1701 1702
    direntry_t* direntries = (direntry_t*)cluster;
    mapping_t* mapping = find_mapping_for_cluster(s, cluster_num);
1703 1704 1705

    long_file_name lfn;
    int path_len = strlen(path);
K
Kevin Wolf 已提交
1706
    char path2[PATH_MAX + 1];
1707 1708

    assert(path_len < PATH_MAX); /* len was tested before! */
B
blueswir1 已提交
1709
    pstrcpy(path2, sizeof(path2), path);
1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722
    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))
1723
	    schedule_rename(s, cluster_num, g_strdup(path));
1724 1725
    } else
	/* new directory */
1726
	schedule_mkdir(s, cluster_num, g_strdup(path));
1727

1728 1729
    lfn_init(&lfn);
    do {
1730
	int i;
1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746
	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:
1747
            g_free(cluster);
1748 1749 1750 1751
	    return 0;
	}

	for (i = 0; i < 0x10 * s->sectors_per_cluster; i++) {
1752
	    int cluster_count = 0;
1753

1754
DLOG(fprintf(stderr, "check direntry %d:\n", i); print_direntry(direntries + i));
1755 1756 1757 1758 1759 1760 1761 1762
	    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;
1763
	    }
1764 1765 1766 1767 1768 1769 1770 1771 1772
	    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
1773 1774
		if (subret > 0 || !strcmp((char*)lfn.name, ".")
			|| !strcmp((char*)lfn.name, ".."))
1775 1776 1777 1778 1779 1780 1781 1782
		    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
1783 1784
            pstrcpy(path2 + path_len + 1, sizeof(path2) - path_len - 1,
                    (char*)lfn.name);
1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806

	    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
1807
                abort(); /* cluster_count = 0; */
1808 1809

	    ret += cluster_count;
1810 1811
	}

1812 1813
	cluster_num = modified_fat_get(s, cluster_num);
    } while(!fat_eof(s, cluster_num));
1814

1815
    g_free(cluster);
1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840
    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;
1841
	s->fat2 = g_malloc(size);
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859
	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
1860
	    mapping_t* mapping = array_get(&(s->mapping), i);
1861 1862
	    if (mapping->first_mapping_index < 0)
		mapping->mode |= MODE_DELETED;
1863
	}
1864 1865 1866 1867 1868

    used_clusters_count = check_directory_consistency(s, 0, s->path);
    if (used_clusters_count <= 0) {
	DLOG(fprintf(stderr, "problem in directory\n"));
	return 0;
1869 1870
    }

1871 1872 1873 1874 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
    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
1900
	mapping_t* mapping = array_get(&(s->mapping), i);
1901 1902 1903 1904 1905 1906 1907 1908

#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);
1909
    }
1910 1911 1912
}

/* insert or update mapping */
A
Anthony Liguori 已提交
1913
static mapping_t* insert_mapping(BDRVVVFATState* s,
1914 1915 1916 1917 1918 1919 1920 1921 1922 1923
	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
1924 1925
    mapping_t* mapping = NULL;
    mapping_t* first_mapping = array_get(&(s->mapping), 0);
1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940

    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;
1941

A
Anthony Liguori 已提交
1942
DLOG(mapping_t* next_mapping;
1943 1944 1945 1946
assert(index + 1 >= s->mapping.next ||
((next_mapping = array_get(&(s->mapping), index + 1)) &&
 next_mapping->begin >= end)));

A
Anthony Liguori 已提交
1947
    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
1948 1949 1950 1951 1952 1953 1954 1955
	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
1956 1957
    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
    mapping_t* first_mapping = array_get(&(s->mapping), 0);
1958 1959

    /* free mapping */
1960 1961 1962
    if (mapping->first_mapping_index < 0) {
        g_free(mapping->path);
    }
1963 1964 1965 1966 1967 1968 1969

    /* 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
1970
    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
1971 1972
	s->current_mapping = array_get(&(s->mapping),
		s->current_mapping - first_mapping);
1973 1974 1975 1976

    return 0;
}

1977 1978 1979 1980
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
1981
	mapping_t* mapping = array_get(&(s->mapping), i);
1982 1983 1984 1985 1986 1987 1988
	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;
    }
}
1989

A
Anthony Liguori 已提交
1990
static direntry_t* insert_direntries(BDRVVVFATState* s,
1991
	int dir_index, int count)
1992
{
1993 1994 1995 1996
    /*
     * make room in s->directory,
     * adjust_dirindices
     */
A
Anthony Liguori 已提交
1997
    direntry_t* result = array_insert(&(s->directory), dir_index, count);
1998 1999 2000
    if (result == NULL)
	return NULL;
    adjust_dirindices(s, dir_index, count);
2001 2002 2003
    return result;
}

2004 2005 2006 2007 2008 2009 2010 2011
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;
}
2012

2013 2014 2015 2016 2017 2018 2019 2020
/*
 * 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)
2021
{
A
Anthony Liguori 已提交
2022 2023
    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2024 2025 2026 2027 2028 2029 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
    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
2055
	    mapping_t* next_mapping = i >= s->mapping.next ? NULL :
2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068
		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;
2069
	    next_mapping->first_mapping_index =
2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088
		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;
	}
2089

2090 2091
	cluster = c1;
    }
2092 2093 2094 2095

    return 0;
}

2096 2097
static int commit_direntries(BDRVVVFATState* s,
	int dir_index, int parent_mapping_index)
2098
{
A
Anthony Liguori 已提交
2099
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2100
    uint32_t first_cluster = dir_index == 0 ? 0 : begin_of_direntry(direntry);
A
Anthony Liguori 已提交
2101
    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127

    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++;
2128

2129 2130 2131 2132
	for (new_cluster_count = 0, c = first_cluster; !fat_eof(s, c);
		c = modified_fat_get(s, c))
	    new_cluster_count++;
    }
2133

2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152
    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;
    }
2153

2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169
    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;
	}
    }
2170

2171 2172
    return 0;
}
2173

2174 2175 2176 2177 2178
/* 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
2179
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2180 2181
    uint32_t c = begin_of_direntry(direntry);
    uint32_t first_cluster = c;
A
Anthony Liguori 已提交
2182
    mapping_t* mapping = find_mapping_for_cluster(s, c);
2183
    uint32_t size = filesize_of_direntry(direntry);
2184
    char* cluster = g_malloc(s->cluster_size);
2185 2186 2187 2188 2189 2190 2191 2192 2193
    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
2194
    fd = open(mapping->path, O_RDWR | O_CREAT | O_BINARY, 0666);
2195 2196 2197
    if (fd < 0) {
	fprintf(stderr, "Could not open %s... (%s, %d)\n", mapping->path,
		strerror(errno), errno);
2198
        g_free(cluster);
2199
	return fd;
2200
    }
2201 2202 2203 2204 2205 2206
    if (offset > 0) {
        if (lseek(fd, offset, SEEK_SET) != offset) {
            g_free(cluster);
            return -3;
        }
    }
2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219

    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
2220
	    (uint8_t*)cluster, (rest_size + 0x1ff) / 0x200);
2221

2222 2223 2224 2225
        if (ret < 0) {
            g_free(cluster);
            return ret;
        }
2226

2227 2228 2229 2230
        if (write(fd, cluster, rest_size) < 0) {
            g_free(cluster);
            return -2;
        }
2231 2232 2233 2234 2235

	offset += rest_size;
	c = c1;
    }

2236 2237 2238
    if (ftruncate(fd, size)) {
        perror("ftruncate()");
        close(fd);
2239
        g_free(cluster);
2240 2241
        return -4;
    }
2242
    close(fd);
2243
    g_free(cluster);
2244 2245 2246 2247 2248 2249 2250 2251 2252 2253

    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
2254
	mapping_t* mapping = array_get(&(s->mapping), i);
2255 2256 2257 2258 2259
	if (mapping->mode & MODE_DELETED) {
	    fprintf(stderr, "deleted\n");
	    continue;
	}
	assert(mapping->dir_index < s->directory.next);
A
Anthony Liguori 已提交
2260
	direntry_t* direntry = array_get(&(s->directory), mapping->dir_index);
2261 2262 2263 2264
	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);
2265 2266 2267 2268
	}
    }
}

2269 2270
/* test, if all direntries have mappings */
static void check2(BDRVVVFATState* s)
2271 2272
{
    int i;
2273
    int first_mapping = -1;
2274

2275
    for (i = 0; i < s->directory.next; i++) {
A
Anthony Liguori 已提交
2276
	direntry_t* direntry = array_get(&(s->directory), i);
2277

2278
	if (is_short_name(direntry) && begin_of_direntry(direntry)) {
A
Anthony Liguori 已提交
2279
	    mapping_t* mapping = find_mapping_for_cluster(s, begin_of_direntry(direntry));
2280 2281 2282 2283
	    assert(mapping);
	    assert(mapping->dir_index == i || is_dot(direntry));
	    assert(mapping->begin == begin_of_direntry(direntry) || is_dot(direntry));
	}
2284

2285 2286 2287
	if ((i % (0x10 * s->sectors_per_cluster)) == 0) {
	    /* cluster start */
	    int j, count = 0;
2288

2289
	    for (j = 0; j < s->mapping.next; j++) {
A
Anthony Liguori 已提交
2290
		mapping_t* mapping = array_get(&(s->mapping), j);
2291
		if (mapping->mode & MODE_DELETED)
2292
		    continue;
2293 2294 2295 2296 2297 2298 2299 2300 2301 2302
		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
2303
			    mapping_t* parent = array_get(&(s->mapping), mapping->info.dir.parent_mapping_index);
2304 2305 2306 2307
			    assert(parent->mode & MODE_DIRECTORY);
			    assert(parent->info.dir.first_dir_index < mapping->info.dir.first_dir_index);
			}
		    }
2308
		}
2309 2310 2311 2312 2313 2314 2315
	    }
	    if (count == 0)
		first_mapping = -1;
	}
    }
}
#endif
2316

2317 2318 2319
static int handle_renames_and_mkdirs(BDRVVVFATState* s)
{
    int i;
2320

2321 2322 2323
#ifdef DEBUG
    fprintf(stderr, "handle_renames\n");
    for (i = 0; i < s->commits.next; i++) {
A
Anthony Liguori 已提交
2324
	commit_t* commit = array_get(&(s->commits), i);
2325 2326 2327 2328 2329
	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
2330
	commit_t* commit = array_get(&(s->commits), i);
2331
	if (commit->action == ACTION_RENAME) {
A
Anthony Liguori 已提交
2332
	    mapping_t* mapping = find_mapping_for_cluster(s,
2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344
		    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
2345
		direntry_t* direntry = array_get(&(s->directory),
2346 2347 2348 2349 2350 2351 2352
			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
2353
			direntry_t* d = direntry + i;
2354 2355

			if (is_file(d) || (is_directory(d) && !is_dot(d))) {
A
Anthony Liguori 已提交
2356
			    mapping_t* m = find_mapping_for_cluster(s,
2357 2358
				    begin_of_direntry(d));
			    int l = strlen(m->path);
2359
			    char* new_path = g_malloc(l + diff + 1);
2360 2361 2362

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

B
blueswir1 已提交
2363 2364 2365
                            pstrcpy(new_path, l + diff + 1, mapping->path);
                            pstrcpy(new_path + l1, l + diff + 1 - l1,
                                    m->path + l2);
2366 2367

			    schedule_rename(s, m->begin, new_path);
2368
			}
2369 2370 2371
			i++;
		    } while((i % (0x10 * s->sectors_per_cluster)) != 0);
		    c = fat_get(s, c);
2372 2373 2374
		}
	    }

2375
            g_free(old_path);
2376 2377 2378
	    array_remove(&(s->commits), i);
	    continue;
	} else if (commit->action == ACTION_MKDIR) {
A
Anthony Liguori 已提交
2379
	    mapping_t* mapping;
2380 2381
	    int j, parent_path_len;

B
bellard 已提交
2382 2383 2384 2385 2386 2387 2388
#ifdef __MINGW32__
            if (mkdir(commit->path))
                return -5;
#else
            if (mkdir(commit->path, 0755))
                return -5;
#endif
2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406

	    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
2407
		mapping_t* m = array_get(&(s->mapping), j);
2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434
		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
2435
	commit_t* commit = array_get(&(s->commits), i);
2436 2437
	switch(commit->action) {
	case ACTION_RENAME: case ACTION_MKDIR:
2438
            abort();
2439 2440 2441
	    fail = -2;
	    break;
	case ACTION_WRITEOUT: {
B
Blue Swirl 已提交
2442 2443
#ifndef NDEBUG
            /* these variables are only used by assert() below */
A
Anthony Liguori 已提交
2444
	    direntry_t* entry = array_get(&(s->directory),
2445 2446
		    commit->param.writeout.dir_index);
	    uint32_t begin = begin_of_direntry(entry);
A
Anthony Liguori 已提交
2447
	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
B
Blue Swirl 已提交
2448
#endif
2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461

	    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
2462 2463
	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
	    direntry_t* entry;
2464
	    int i;
2465

2466 2467 2468 2469 2470
	    /* 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;
2471 2472
	    }

2473 2474 2475 2476
	    if (i >= s->directory.next) {
		fail = -6;
		continue;
	    }
2477

2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498
	    /* 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:
2499
            abort();
2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517
	}
    }
    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
2518
	    mapping_t* mapping = array_get(&(s->mapping), i);
2519
	    if (mapping->mode & MODE_DELETED) {
A
Anthony Liguori 已提交
2520
		direntry_t* entry = array_get(&(s->directory),
2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534
			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;
2535
			}
2536 2537

			for (j = 1; j < s->mapping.next; j++) {
A
Anthony Liguori 已提交
2538
			    mapping_t* m = array_get(&(s->mapping), j);
2539 2540 2541 2542 2543 2544 2545
			    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;
2546
			}
2547 2548
			remove_direntries(s, first_dir_index,
				next_dir_index - first_dir_index);
2549

2550
			deleted++;
2551
		    }
2552 2553 2554 2555
		} else {
		    if (unlink(mapping->path))
			return -4;
		    deleted++;
2556
		}
2557 2558
		DLOG(fprintf(stderr, "DELETE (%d)\n", i); print_mapping(mapping); print_direntry(entry));
		remove_mapping(s, i);
2559 2560 2561
	    }
	}
    }
2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586

    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);
2587
        abort();
2588 2589 2590
	return ret;
    }

2591
    /* copy FAT (with bdrv_read) */
2592 2593 2594 2595 2596 2597
    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);
2598
        abort();
2599 2600 2601 2602 2603 2604
	return ret;
    }

    ret = handle_commits(s);
    if (ret) {
	fprintf(stderr, "Error handling commits (%d)\n", ret);
2605
        abort();
2606 2607 2608 2609 2610 2611
	return ret;
    }

    ret = handle_deletes(s);
    if (ret) {
	fprintf(stderr, "Error deleting\n");
2612
        abort();
2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
	return ret;
    }

    s->qcow->drv->bdrv_make_empty(s->qcow);

    memset(s->used_clusters, 0, sector2cluster(s, s->sector_count));

DLOG(checkpoint());
    return 0;
}

static int try_commit(BDRVVVFATState* s)
{
    vvfat_close_current_file(s);
DLOG(checkpoint());
    if(!is_consistent(s))
	return -1;
    return do_commit(s);
}

2633
static int vvfat_write(BlockDriverState *bs, int64_t sector_num,
2634 2635
                    const uint8_t *buf, int nb_sectors)
{
2636
    BDRVVVFATState *s = bs->opaque;
2637 2638 2639 2640
    int i, ret;

DLOG(checkpoint());

2641 2642 2643 2644 2645
    /* Check if we're operating in read-only mode */
    if (s->qcow == NULL) {
        return -EACCES;
    }

2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658
    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
2659
	mapping_t* mapping = find_mapping_for_cluster(s, i);
2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670
	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
2671
		const direntry_t* direntries;
2672 2673 2674 2675 2676 2677 2678 2679
		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;
2680
		dir_index  = mapping->dir_index +
2681
		    0x10 * (begin - mapping->begin * s->sectors_per_cluster);
A
Anthony Liguori 已提交
2682
		direntries = (direntry_t*)(buf + 0x200 * (begin - sector_num));
2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694

		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
2695
				    sizeof(direntry_t))) {
2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738
			    fprintf(stderr, "Warning: tried to write to write-protected file\n");
			    return -1;
			}
		    }
		}
	    }
	    i = mapping->end;
	} else
	    i++;
    }

    /*
     * Use qcow backend. Commit later.
     */
DLOG(fprintf(stderr, "Write to qcow backend: %d + %d\n", (int)sector_num, nb_sectors));
    ret = s->qcow->drv->bdrv_write(s->qcow, sector_num, buf, nb_sectors);
    if (ret < 0) {
	fprintf(stderr, "Error writing to qcow backend\n");
	return ret;
    }

    for (i = sector2cluster(s, sector_num);
	    i <= sector2cluster(s, sector_num + nb_sectors - 1); i++)
	if (i >= 0)
	    s->used_clusters[i] |= USED_ALLOCATED;

DLOG(checkpoint());
    /* TODO: add timeout */
    try_commit(s);

DLOG(checkpoint());
    return 0;
}

static int vvfat_is_allocated(BlockDriverState *bs,
	int64_t sector_num, int nb_sectors, int* n)
{
    BDRVVVFATState* s = bs->opaque;
    *n = s->sector_count - sector_num;
    if (*n > nb_sectors)
	*n = nb_sectors;
    else if (*n < 0)
	return 0;
2739
    return 1;
2740 2741 2742 2743
}

static int write_target_commit(BlockDriverState *bs, int64_t sector_num,
	const uint8_t* buffer, int nb_sectors) {
2744
    BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
2745 2746 2747 2748
    return try_commit(s);
}

static void write_target_close(BlockDriverState *bs) {
2749
    BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
2750
    bdrv_delete(s->qcow);
2751
    g_free(s->qcow_filename);
2752 2753 2754
}

static BlockDriver vvfat_write_target = {
2755 2756 2757
    .format_name        = "vvfat_write_target",
    .bdrv_write         = write_target_commit,
    .bdrv_close         = write_target_close,
2758 2759 2760 2761
};

static int enable_write_target(BDRVVVFATState *s)
{
K
Kevin Wolf 已提交
2762 2763
    BlockDriver *bdrv_qcow;
    QEMUOptionParameter *options;
K
Kevin Wolf 已提交
2764
    int ret;
2765 2766 2767
    int size = sector2cluster(s, s->sector_count);
    s->used_clusters = calloc(size, 1);

A
Anthony Liguori 已提交
2768
    array_init(&(s->commits), sizeof(commit_t));
2769

2770
    s->qcow_filename = g_malloc(1024);
B
bellard 已提交
2771
    get_tmp_filename(s->qcow_filename, 1024);
K
Kevin Wolf 已提交
2772 2773 2774 2775 2776 2777 2778

    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)
2779
	return -1;
K
Kevin Wolf 已提交
2780

2781
    s->qcow = bdrv_new("");
K
Kevin Wolf 已提交
2782 2783 2784 2785 2786 2787 2788 2789
    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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    }
2791 2792 2793 2794 2795 2796 2797

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

    s->bs->backing_hd = calloc(sizeof(BlockDriverState), 1);
    s->bs->backing_hd->drv = &vvfat_write_target;
2798
    s->bs->backing_hd->opaque = g_malloc(sizeof(void*));
2799
    *(void**)s->bs->backing_hd->opaque = s;
2800

2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811
    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));
2812
    g_free(s->cluster_buffer);
2813 2814
}

2815
static BlockDriver bdrv_vvfat = {
2816 2817
    .format_name	= "vvfat",
    .instance_size	= sizeof(BDRVVVFATState),
2818
    .bdrv_file_open	= vvfat_open,
2819
    .bdrv_read          = vvfat_co_read,
2820 2821 2822 2823
    .bdrv_write		= vvfat_write,
    .bdrv_close		= vvfat_close,
    .bdrv_is_allocated	= vvfat_is_allocated,
    .protocol_name	= "fat",
2824 2825
};

2826 2827 2828 2829 2830 2831 2832
static void bdrv_vvfat_init(void)
{
    bdrv_register(&bdrv_vvfat);
}

block_init(bdrv_vvfat_init);

2833
#ifdef DEBUG
2834
static void checkpoint(void) {
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    assert(((mapping_t*)array_get(&(vvv->mapping), 0))->end == 2);
2836 2837 2838 2839
    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)
2841
	fprintf(stderr, "Nonono!\n");
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    mapping_t* mapping;
    direntry_t* direntry;
2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854
    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