vvfat.c 84.5 KB
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/* vim:set shiftwidth=4 ts=4: */
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/*
 * QEMU Block driver for virtual VFAT (shadows a local directory)
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 *
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 * Copyright (c) 2004,2005 Johannes E. Schindelin
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include <sys/stat.h>
#include <dirent.h>
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#include "qemu-common.h"
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#include "block/block_int.h"
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#include "qemu/module.h"
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#include "migration/migration.h"
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#include "qapi/qmp/qint.h"
#include "qapi/qmp/qbool.h"
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#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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    Error *migration_blocker;
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} BDRVVVFATState;

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/* take the sector position spos and convert it to Cylinder/Head/Sector position
 * if the position is outside the specified geometry, fill maximum value for CHS
 * and return 1 to signal overflow.
 */
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static int sector2CHS(mbr_chs_t *chs, int spos, int cyls, int heads, int secs)
{
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    int head,sector;
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    sector   = spos % secs;  spos /= secs;
    head     = spos % heads; spos /= heads;
    if (spos >= cyls) {
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        /* Overflow,
        it happens if 32bit sector positions are used, while CHS is only 24bit.
        Windows/Dos is said to take 1023/255/63 as nonrepresentable CHS */
        chs->head     = 0xFF;
        chs->sector   = 0xFF;
        chs->cylinder = 0xFF;
        return 1;
    }
    chs->head     = (uint8_t)head;
    chs->sector   = (uint8_t)( (sector+1) | ((spos>>8)<<6) );
    chs->cylinder = (uint8_t)spos;
    return 0;
}
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static void init_mbr(BDRVVVFATState *s, int cyls, int heads, int secs)
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{
    /* TODO: if the files mbr.img and bootsect.img exist, use them */
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    mbr_t* real_mbr=(mbr_t*)s->first_sectors;
    partition_t* partition = &(real_mbr->partition[0]);
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    int lba;
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    memset(s->first_sectors,0,512);
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    /* Win NT Disk Signature */
    real_mbr->nt_id= cpu_to_le32(0xbe1afdfa);

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    partition->attributes=0x80; /* bootable */
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    /* LBA is used when partition is outside the CHS geometry */
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    lba  = sector2CHS(&partition->start_CHS, s->first_sectors_number - 1,
                     cyls, heads, secs);
    lba |= sector2CHS(&partition->end_CHS,   s->bs->total_sectors - 1,
                     cyls, heads, secs);
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    /*LBA partitions are identified only by start/length_sector_long not by CHS*/
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    partition->start_sector_long  = cpu_to_le32(s->first_sectors_number - 1);
    partition->length_sector_long = cpu_to_le32(s->bs->total_sectors
                                                - s->first_sectors_number + 1);
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    /* FAT12/FAT16/FAT32 */
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    /* DOS uses different types when partition is LBA,
       probably to prevent older versions from using CHS on them */
    partition->fs_type= s->fat_type==12 ? 0x1:
                        s->fat_type==16 ? (lba?0xe:0x06):
                         /*fat_tyoe==32*/ (lba?0xc:0x0b);
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    real_mbr->magic[0]=0x55; real_mbr->magic[1]=0xaa;
}

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/* direntry functions */

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

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static inline direntry_t* create_long_filename(BDRVVVFATState* s,const char* filename)
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{
    char buffer[258];
    int length=short2long_name(buffer,filename),
        number_of_entries=(length+25)/26,i;
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    direntry_t* entry;
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    for(i=0;i<number_of_entries;i++) {
	entry=array_get_next(&(s->directory));
	entry->attributes=0xf;
	entry->reserved[0]=0;
	entry->begin=0;
	entry->name[0]=(number_of_entries-i)|(i==0?0x40:0);
    }
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    for(i=0;i<26*number_of_entries;i++) {
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	int offset=(i%26);
	if(offset<10) offset=1+offset;
	else if(offset<22) offset=14+offset-10;
	else offset=28+offset-22;
	entry=array_get(&(s->directory),s->directory.next-1-(i/26));
	entry->name[offset]=buffer[i];
    }
    return array_get(&(s->directory),s->directory.next-number_of_entries);
}

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

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

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

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

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

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

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

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

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

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

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/* fat functions */

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

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    for(i=0;i<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;
    struct tm t1;
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    t = &t1;
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    localtime_r(&time,t);
    if(return_time)
	return cpu_to_le16((t->tm_sec/2)|(t->tm_min<<5)|(t->tm_hour<<11));
    return cpu_to_le16((t->tm_mday)|((t->tm_mon+1)<<5)|((t->tm_year-80)<<9));
}

static inline void fat_set(BDRVVVFATState* s,unsigned int cluster,uint32_t value)
{
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    if(s->fat_type==32) {
	uint32_t* entry=array_get(&(s->fat),cluster);
	*entry=cpu_to_le32(value);
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    } else if(s->fat_type==16) {
	uint16_t* entry=array_get(&(s->fat),cluster);
	*entry=cpu_to_le16(value&0xffff);
    } else {
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	int offset = (cluster*3/2);
	unsigned char* p = array_get(&(s->fat), offset);
        switch (cluster&1) {
	case 0:
		p[0] = value&0xff;
		p[1] = (p[1]&0xf0) | ((value>>8)&0xf);
		break;
	case 1:
		p[0] = (p[0]&0xf) | ((value&0xf)<<4);
		p[1] = (value>>4);
		break;
	}
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    }
}

static inline uint32_t fat_get(BDRVVVFATState* s,unsigned int cluster)
{
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    if(s->fat_type==32) {
	uint32_t* entry=array_get(&(s->fat),cluster);
	return le32_to_cpu(*entry);
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    } else if(s->fat_type==16) {
	uint16_t* entry=array_get(&(s->fat),cluster);
	return le16_to_cpu(*entry);
    } else {
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	const uint8_t* x=(uint8_t*)(s->fat.pointer)+cluster*3/2;
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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)
{
589 590 591 592 593 594 595 596 597
    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);
    }
598
    memset(s->fat.pointer,0,s->fat.size);
599

600 601 602
    switch(s->fat_type) {
	case 12: s->max_fat_value=0xfff; break;
	case 16: s->max_fat_value=0xffff; break;
603
	case 32: s->max_fat_value=0x0fffffff; break;
604 605 606 607 608
	default: s->max_fat_value=0; /* error... */
    }

}

609 610
/* TODO: in create_short_filename, 0xe5->0x05 is not yet handled! */
/* TODO: in parse_short_filename, 0x05->0xe5 is not yet handled! */
A
Anthony Liguori 已提交
611
static inline direntry_t* create_short_and_long_name(BDRVVVFATState* s,
612
	unsigned int directory_start, const char* filename, int is_dot)
613
{
614
    int i,j,long_index=s->directory.next;
A
Anthony Liguori 已提交
615 616
    direntry_t* entry = NULL;
    direntry_t* entry_long = NULL;
617 618 619 620 621 622 623

    if(is_dot) {
	entry=array_get_next(&(s->directory));
	memset(entry->name,0x20,11);
	memcpy(entry->name,filename,strlen(filename));
	return entry;
    }
624

625
    entry_long=create_long_filename(s,filename);
626

627
    i = strlen(filename);
628 629 630 631 632 633
    for(j = i - 1; j>0  && filename[j]!='.';j--);
    if (j > 0)
	i = (j > 8 ? 8 : j);
    else if (i > 8)
	i = 8;

634 635
    entry=array_get_next(&(s->directory));
    memset(entry->name,0x20,11);
B
blueswir1 已提交
636
    memcpy(entry->name, filename, i);
637

638 639 640
    if(j > 0)
	for (i = 0; i < 3 && filename[j+1+i]; i++)
	    entry->extension[i] = filename[j+1+i];
641 642 643

    /* upcase & remove unwanted characters */
    for(i=10;i>=0;i--) {
644
	if(i==10 || i==7) for(;i>0 && entry->name[i]==' ';i--);
645
	if(entry->name[i]<=' ' || entry->name[i]>0x7f
646
		|| strchr(".*?<>|\":/\\[];,+='",entry->name[i]))
647 648 649 650 651 652 653
	    entry->name[i]='_';
        else if(entry->name[i]>='a' && entry->name[i]<='z')
            entry->name[i]+='A'-'a';
    }

    /* mangle duplicates */
    while(1) {
A
Anthony Liguori 已提交
654
	direntry_t* entry1=array_get(&(s->directory),directory_start);
655 656 657
	int j;

	for(;entry1<entry;entry1++)
658
	    if(!is_long_name(entry1) && !memcmp(entry1->name,entry->name,11))
659 660 661 662
		break; /* found dupe */
	if(entry1==entry) /* no dupe found */
	    break;

663
	/* use all 8 characters of name */
664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686
	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);
687
	while(entry_long<entry && is_long_name(entry_long)) {
688 689 690 691 692 693 694 695
	    entry_long->reserved[1]=chksum;
	    entry_long++;
	}
    }

    return entry;
}

696 697 698 699
/*
 * Read a directory. (the index of the corresponding mapping must be passed).
 */
static int read_directory(BDRVVVFATState* s, int mapping_index)
700
{
A
Anthony Liguori 已提交
701 702
    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
    direntry_t* direntry;
703 704 705
    const char* dirname = mapping->path;
    int first_cluster = mapping->begin;
    int parent_index = mapping->info.dir.parent_mapping_index;
A
Anthony Liguori 已提交
706
    mapping_t* parent_mapping = (mapping_t*)
707
        (parent_index >= 0 ? array_get(&(s->mapping), parent_index) : NULL);
708
    int first_cluster_of_parent = parent_mapping ? parent_mapping->begin : -1;
709 710 711 712 713

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

714 715 716 717
    assert(mapping->mode & MODE_DIRECTORY);

    if(!dir) {
	mapping->end = mapping->begin;
718
	return -1;
719
    }
720

721 722 723
    i = mapping->info.dir.first_dir_index =
	    first_cluster == 0 ? 0 : s->directory.next;

724
    /* actually read the directory, and allocate the mappings */
725 726 727
    while((entry=readdir(dir))) {
	unsigned int length=strlen(dirname)+2+strlen(entry->d_name);
        char* buffer;
A
Anthony Liguori 已提交
728
	direntry_t* direntry;
729
        struct stat st;
730 731 732
	int is_dot=!strcmp(entry->d_name,".");
	int is_dotdot=!strcmp(entry->d_name,"..");

733
	if(first_cluster == 0 && (is_dotdot || is_dot))
734
	    continue;
735

736
	buffer=(char*)g_malloc(length);
737 738 739
	snprintf(buffer,length,"%s/%s",dirname,entry->d_name);

	if(stat(buffer,&st)<0) {
740
            g_free(buffer);
741 742 743 744
            continue;
	}

	/* create directory entry for this file */
745 746
	direntry=create_short_and_long_name(s, i, entry->d_name,
		is_dot || is_dotdot);
747 748 749 750 751 752 753 754 755
	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)
756
	    set_begin_of_direntry(direntry, first_cluster_of_parent);
757
	else if(is_dot)
758
	    set_begin_of_direntry(direntry, first_cluster);
759
	else
760 761 762
	    direntry->begin=0; /* do that later */
        if (st.st_size > 0x7fffffff) {
	    fprintf(stderr, "File %s is larger than 2GB\n", buffer);
763
            g_free(buffer);
B
Blue Swirl 已提交
764
            closedir(dir);
765 766 767
	    return -2;
        }
	direntry->size=cpu_to_le32(S_ISDIR(st.st_mode)?0:st.st_size);
768 769

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

    /* fill with zeroes up to the end of the cluster */
    while(s->directory.next%(0x10*s->sectors_per_cluster)) {
A
Anthony Liguori 已提交
797 798
	direntry_t* direntry=array_get_next(&(s->directory));
	memset(direntry,0,sizeof(direntry_t));
799 800
    }

801 802 803 804 805 806
/* 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);
807
	s->directory.next = ROOT_ENTRIES;
808
	memset(array_get(&(s->directory), cur), 0,
A
Anthony Liguori 已提交
809
		(ROOT_ENTRIES - cur) * sizeof(direntry_t));
810
    }
811

812
     /* reget the mapping, since s->mapping was possibly realloc()ed */
A
Anthony Liguori 已提交
813
    mapping = (mapping_t*)array_get(&(s->mapping), mapping_index);
814 815 816 817
    first_cluster += (s->directory.next - mapping->info.dir.first_dir_index)
	* 0x20 / s->cluster_size;
    mapping->end = first_cluster;

A
Anthony Liguori 已提交
818
    direntry = (direntry_t*)array_get(&(s->directory), mapping->dir_index);
819
    set_begin_of_direntry(direntry, mapping->begin);
820

821 822
    return 0;
}
823

824 825 826 827
static inline uint32_t sector2cluster(BDRVVVFATState* s,off_t sector_num)
{
    return (sector_num-s->faked_sectors)/s->sectors_per_cluster;
}
828

829 830 831 832
static inline off_t cluster2sector(BDRVVVFATState* s, uint32_t cluster_num)
{
    return s->faked_sectors + s->sectors_per_cluster * cluster_num;
}
833

834
static int init_directories(BDRVVVFATState* s,
835
                            const char *dirname, int heads, int secs)
836
{
A
Anthony Liguori 已提交
837 838
    bootsector_t* bootsector;
    mapping_t* mapping;
839 840 841 842 843 844
    unsigned int i;
    unsigned int cluster;

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

    s->cluster_size=s->sectors_per_cluster*0x200;
845
    s->cluster_buffer=g_malloc(s->cluster_size);
846 847 848 849 850 851 852 853 854 855

    /*
     * 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 */
856

A
Anthony Liguori 已提交
857 858
    array_init(&(s->mapping),sizeof(mapping_t));
    array_init(&(s->directory),sizeof(direntry_t));
859 860 861

    /* add volume label */
    {
A
Anthony Liguori 已提交
862
	direntry_t* entry=array_get_next(&(s->directory));
863
	entry->attributes=0x28; /* archive | volume label */
864 865
	memcpy(entry->name,"QEMU VVF",8);
	memcpy(entry->extension,"AT ",3);
866 867 868 869 870
    }

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

871 872 873 874 875 876 877 878
    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;
879
    mapping->path = g_strdup(dirname);
880 881 882 883 884 885 886 887
    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++) {
888
	/* MS-DOS expects the FAT to be 0 for the root directory
889 890 891 892 893 894 895 896 897 898
	 * (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);
899 900
		return -1;
	    }
901 902 903
	    mapping = array_get(&(s->mapping), i);
	} else {
	    assert(mapping->mode == MODE_UNDEFINED);
904
	    mapping->mode=MODE_NORMAL;
905 906
	    mapping->begin = cluster;
	    if (mapping->end > 0) {
A
Anthony Liguori 已提交
907
		direntry_t* direntry = array_get(&(s->directory),
908 909 910 911 912 913 914
			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;
915
	    }
916 917 918 919
	}

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

920 921 922 923
	/* next free cluster */
	cluster = mapping->end;

	if(cluster > s->cluster_count) {
924 925
	    fprintf(stderr,"Directory does not fit in FAT%d (capacity %.2f MB)\n",
		    s->fat_type, s->sector_count / 2000.0);
926 927 928
	    return -EINVAL;
	}

929 930
	/* fix fat for entry */
	if (fix_fat) {
931
	    int j;
932 933 934 935
	    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);
	}
936 937
    }

938 939 940 941 942 943 944
    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);
945

946 947
    s->current_mapping = NULL;

A
Anthony Liguori 已提交
948
    bootsector=(bootsector_t*)(s->first_sectors+(s->first_sectors_number-1)*0x200);
949 950 951 952 953 954 955 956 957
    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);
958
    bootsector->total_sectors16=s->sector_count>0xffff?0:cpu_to_le16(s->sector_count);
959
    bootsector->media_type=(s->first_sectors_number>1?0xf8:0xf0); /* media descriptor (f8=hd, f0=3.5 fd)*/
960
    s->fat.pointer[0] = bootsector->media_type;
961
    bootsector->sectors_per_fat=cpu_to_le16(s->sectors_per_fat);
962 963
    bootsector->sectors_per_track = cpu_to_le16(secs);
    bootsector->number_of_heads = cpu_to_le16(heads);
964
    bootsector->hidden_sectors=cpu_to_le32(s->first_sectors_number==1?0:0x3f);
965
    bootsector->total_sectors=cpu_to_le32(s->sector_count>0xffff?s->sector_count:0);
966

967
    /* LATER TODO: if FAT32, this is wrong */
968
    bootsector->u.fat16.drive_number=s->first_sectors_number==1?0:0x80; /* fda=0, hda=0x80 */
969 970 971 972 973 974 975 976 977 978 979
    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
980
#ifdef DEBUG
981
static BDRVVVFATState *vvv = NULL;
B
bellard 已提交
982
#endif
983 984 985 986

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

P
Paolo Bonzini 已提交
987 988 989 990 991 992
static void vvfat_rebind(BlockDriverState *bs)
{
    BDRVVVFATState *s = bs->opaque;
    s->bs = bs;
}

993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067
static QemuOptsList runtime_opts = {
    .name = "vvfat",
    .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
    .desc = {
        {
            .name = "dir",
            .type = QEMU_OPT_STRING,
            .help = "Host directory to map to the vvfat device",
        },
        {
            .name = "fat-type",
            .type = QEMU_OPT_NUMBER,
            .help = "FAT type (12, 16 or 32)",
        },
        {
            .name = "floppy",
            .type = QEMU_OPT_BOOL,
            .help = "Create a floppy rather than a hard disk image",
        },
        {
            .name = "rw",
            .type = QEMU_OPT_BOOL,
            .help = "Make the image writable",
        },
        { /* end of list */ }
    },
};

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

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

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

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

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

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

    /* Fill in the options QDict */
    qdict_put(options, "dir", qstring_from_str(filename));
    qdict_put(options, "fat-type", qint_from_int(fat_type));
    qdict_put(options, "floppy", qbool_from_int(floppy));
    qdict_put(options, "rw", qbool_from_int(rw));
}

1068
static int vvfat_open(BlockDriverState *bs, QDict *options, int flags)
1069 1070
{
    BDRVVVFATState *s = bs->opaque;
1071 1072 1073 1074 1075 1076
    int cyls, heads, secs;
    bool floppy;
    const char *dirname;
    QemuOpts *opts;
    Error *local_err = NULL;
    int ret;
1077

B
bellard 已提交
1078
#ifdef DEBUG
1079
    vvv = s;
B
bellard 已提交
1080
#endif
1081 1082 1083 1084 1085 1086

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

1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145
    opts = qemu_opts_create_nofail(&runtime_opts);
    qemu_opts_absorb_qdict(opts, options, &local_err);
    if (error_is_set(&local_err)) {
        qerror_report_err(local_err);
        error_free(local_err);
        ret = -EINVAL;
        goto fail;
    }

    dirname = qemu_opt_get(opts, "dir");
    if (!dirname) {
        qerror_report(ERROR_CLASS_GENERIC_ERROR, "vvfat block driver requires "
                      "a 'dir' option");
        ret = -EINVAL;
        goto fail;
    }

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

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

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


1146 1147 1148 1149
    s->bs = bs;

    /* LATER TODO: if FAT32, adjust */
    s->sectors_per_cluster=0x10;
1150 1151 1152 1153

    s->current_cluster=0xffffffff;

    s->first_sectors_number=0x40;
1154 1155 1156 1157 1158 1159
    /* 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;
1160

1161 1162
    fprintf(stderr, "vvfat %s chs %d,%d,%d\n",
            dirname, cyls, heads, secs);
1163

1164
    s->sector_count = cyls * heads * secs - (s->first_sectors_number - 1);
1165

1166
    if (qemu_opt_get_bool(opts, "rw", false)) {
1167 1168
        ret = enable_write_target(s);
        if (ret < 0) {
1169 1170 1171
            goto fail;
        }
        bs->read_only = 0;
T
ths 已提交
1172 1173
    }

1174
    bs->total_sectors = cyls * heads * secs;
T
ths 已提交
1175

1176
    if (init_directories(s, dirname, heads, secs)) {
1177 1178
        ret = -EIO;
        goto fail;
1179
    }
1180

T
ths 已提交
1181 1182
    s->sector_count = s->faked_sectors + s->sectors_per_cluster*s->cluster_count;

1183 1184
    if (s->first_sectors_number == 0x40) {
        init_mbr(s, cyls, heads, secs);
1185
    }
1186 1187

    //    assert(is_consistent(s));
1188
    qemu_co_mutex_init(&s->lock);
K
Kevin Wolf 已提交
1189 1190 1191 1192 1193 1194 1195 1196 1197

    /* Disable migration when vvfat is used rw */
    if (s->qcow) {
        error_set(&s->migration_blocker,
                  QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
                  "vvfat (rw)", bs->device_name, "live migration");
        migrate_add_blocker(s->migration_blocker);
    }

1198 1199 1200 1201
    ret = 0;
fail:
    qemu_opts_del(opts);
    return ret;
1202 1203 1204 1205 1206
}

static inline void vvfat_close_current_file(BDRVVVFATState *s)
{
    if(s->current_mapping) {
1207 1208
	s->current_mapping = NULL;
	if (s->current_fd) {
1209
		qemu_close(s->current_fd);
1210 1211
		s->current_fd = 0;
	}
1212
    }
1213
    s->current_cluster = -1;
1214 1215 1216 1217 1218 1219 1220 1221
}

/* 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) {
1222
        int index3;
A
Anthony Liguori 已提交
1223
	mapping_t* mapping;
1224 1225
	index3=(index1+index2)/2;
	mapping=array_get(&(s->mapping),index3);
1226 1227
	assert(mapping->begin < mapping->end);
	if(mapping->begin>=cluster_num) {
1228 1229
	    assert(index2!=index3 || index2==0);
	    if(index2==index3)
1230
		return index1;
1231 1232 1233
	    index2=index3;
	} else {
	    if(index1==index3)
1234
		return mapping->end<=cluster_num ? index2 : index1;
1235 1236 1237
	    index1=index3;
	}
	assert(index1<=index2);
1238 1239
	DLOG(mapping=array_get(&(s->mapping),index1);
	assert(mapping->begin<=cluster_num);
1240
	assert(index2 >= s->mapping.next ||
1241 1242
		((mapping = array_get(&(s->mapping),index2)) &&
		mapping->end>cluster_num)));
1243 1244 1245
    }
}

A
Anthony Liguori 已提交
1246
static inline mapping_t* find_mapping_for_cluster(BDRVVVFATState* s,int cluster_num)
1247 1248
{
    int index=find_mapping_for_cluster_aux(s,cluster_num,0,s->mapping.next);
A
Anthony Liguori 已提交
1249
    mapping_t* mapping;
1250
    if(index>=s->mapping.next)
1251
        return NULL;
1252 1253
    mapping=array_get(&(s->mapping),index);
    if(mapping->begin>cluster_num)
1254
        return NULL;
1255
    assert(mapping->begin<=cluster_num && mapping->end>cluster_num);
1256 1257 1258
    return mapping;
}

A
Anthony Liguori 已提交
1259
static int open_file(BDRVVVFATState* s,mapping_t* mapping)
1260 1261 1262 1263
{
    if(!mapping)
	return -1;
    if(!s->current_mapping ||
1264
	    strcmp(s->current_mapping->path,mapping->path)) {
1265
	/* open file */
1266
	int fd = qemu_open(mapping->path, O_RDONLY | O_BINARY | O_LARGEFILE);
1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280
	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;
1281
	assert(!s->current_mapping || s->current_fd || (s->current_mapping->mode & MODE_DIRECTORY));
1282 1283 1284 1285
	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
1286
	    mapping_t* mapping=find_mapping_for_cluster(s,cluster_num);
1287 1288 1289 1290 1291 1292 1293 1294

	    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
1295
		s->cluster = (unsigned char*)s->directory.pointer+offset
1296 1297 1298 1299 1300 1301 1302 1303
			+ 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))
1304
		return -2;
1305 1306
	} else if (s->current_mapping->mode & MODE_DIRECTORY)
	    goto read_cluster_directory;
1307

1308 1309 1310
	assert(s->current_fd);

	offset=s->cluster_size*(cluster_num-s->current_mapping->begin)+s->current_mapping->info.file.offset;
1311 1312
	if(lseek(s->current_fd, offset, SEEK_SET)!=offset)
	    return -3;
1313
	s->cluster=s->cluster_buffer;
1314 1315 1316 1317 1318 1319 1320 1321 1322 1323
	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;
}

1324
#ifdef DEBUG
A
Anthony Liguori 已提交
1325
static void print_direntry(const direntry_t* direntry)
1326
{
1327 1328 1329
    int j = 0;
    char buffer[1024];

K
Kevin Wolf 已提交
1330
    fprintf(stderr, "direntry %p: ", direntry);
1331 1332
    if(!direntry)
	return;
1333
    if(is_long_name(direntry)) {
1334 1335 1336
	unsigned char* c=(unsigned char*)direntry;
	int i;
	for(i=1;i<11 && c[i] && c[i]!=0xff;i+=2)
1337
#define ADD_CHAR(c) {buffer[j] = (c); if (buffer[j] < ' ') buffer[j] = 0xb0; j++;}
1338
	    ADD_CHAR(c[i]);
1339
	for(i=14;i<26 && c[i] && c[i]!=0xff;i+=2)
1340
	    ADD_CHAR(c[i]);
1341
	for(i=28;i<32 && c[i] && c[i]!=0xff;i+=2)
1342 1343 1344
	    ADD_CHAR(c[i]);
	buffer[j] = 0;
	fprintf(stderr, "%s\n", buffer);
1345 1346 1347
    } else {
	int i;
	for(i=0;i<11;i++)
1348 1349 1350 1351
	    ADD_CHAR(direntry->name[i]);
	buffer[j] = 0;
	fprintf(stderr,"%s attributes=0x%02x begin=%d size=%d\n",
		buffer,
1352
		direntry->attributes,
1353
		begin_of_direntry(direntry),le32_to_cpu(direntry->size));
1354 1355 1356
    }
}

A
Anthony Liguori 已提交
1357
static void print_mapping(const mapping_t* mapping)
1358
{
K
Kevin Wolf 已提交
1359 1360 1361 1362 1363
    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);

1364 1365 1366 1367
    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);
1368
}
1369
#endif
1370

1371
static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
1372
                    uint8_t *buf, int nb_sectors)
1373
{
1374
    BDRVVVFATState *s = bs->opaque;
1375 1376
    int i;

1377
    for(i=0;i<nb_sectors;i++,sector_num++) {
1378
	if (sector_num >= bs->total_sectors)
1379 1380 1381
	   return -1;
	if (s->qcow) {
	    int n;
K
Kevin Wolf 已提交
1382
            if (bdrv_is_allocated(s->qcow, sector_num, nb_sectors-i, &n)) {
1383
DLOG(fprintf(stderr, "sectors %d+%d allocated\n", (int)sector_num, n));
K
Kevin Wolf 已提交
1384 1385 1386 1387 1388 1389 1390
                if (bdrv_read(s->qcow, sector_num, buf + i*0x200, n)) {
                    return -1;
                }
                i += n - 1;
                sector_num += n - 1;
                continue;
            }
1391
DLOG(fprintf(stderr, "sector %d not allocated\n", (int)sector_num));
1392
	}
1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
	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;
1404
	    if(cluster_num > s->cluster_count || read_cluster(s, cluster_num) != 0) {
1405 1406 1407
		/* LATER TODO: strict: return -1; */
		memset(buf+i*0x200,0,0x200);
		continue;
1408
	    }
1409
	    memcpy(buf+i*0x200,s->cluster+sector_offset_in_cluster*0x200,0x200);
1410 1411 1412 1413 1414
	}
    }
    return 0;
}

1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425
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;
}

1426
/* LATER TODO: statify all functions */
1427

1428 1429
/*
 * Idea of the write support (use snapshot):
1430
 *
1431 1432
 * 1. check if all data is consistent, recording renames, modifications,
 *    new files and directories (in s->commits).
1433
 *
1434
 * 2. if the data is not consistent, stop committing
1435
 *
1436 1437
 * 3. handle renames, and create new files and directories (do not yet
 *    write their contents)
1438
 *
1439 1440
 * 4. walk the directories, fixing the mapping and direntries, and marking
 *    the handled mappings as not deleted
1441
 *
1442
 * 5. commit the contents of the files
1443
 *
1444
 * 6. handle deleted files and directories
1445 1446 1447
 *
 */

A
Anthony Liguori 已提交
1448
typedef struct commit_t {
1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459
    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
1460
} commit_t;
1461

1462
static void clear_commits(BDRVVVFATState* s)
1463 1464
{
    int i;
1465 1466
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
1467
	commit_t* commit = array_get(&(s->commits), i);
1468 1469 1470
	assert(commit->path || commit->action == ACTION_WRITEOUT);
	if (commit->action != ACTION_WRITEOUT) {
	    assert(commit->path);
1471
            g_free(commit->path);
1472 1473
	} else
	    assert(commit->path == NULL);
1474
    }
1475
    s->commits.next = 0;
1476 1477
}

1478 1479
static void schedule_rename(BDRVVVFATState* s,
	uint32_t cluster, char* new_path)
1480
{
A
Anthony Liguori 已提交
1481
    commit_t* commit = array_get_next(&(s->commits));
1482 1483 1484
    commit->path = new_path;
    commit->param.rename.cluster = cluster;
    commit->action = ACTION_RENAME;
1485 1486
}

1487 1488
static void schedule_writeout(BDRVVVFATState* s,
	int dir_index, uint32_t modified_offset)
1489
{
A
Anthony Liguori 已提交
1490
    commit_t* commit = array_get_next(&(s->commits));
1491 1492 1493 1494
    commit->path = NULL;
    commit->param.writeout.dir_index = dir_index;
    commit->param.writeout.modified_offset = modified_offset;
    commit->action = ACTION_WRITEOUT;
1495 1496
}

1497 1498
static void schedule_new_file(BDRVVVFATState* s,
	char* path, uint32_t first_cluster)
1499
{
A
Anthony Liguori 已提交
1500
    commit_t* commit = array_get_next(&(s->commits));
1501 1502 1503 1504 1505 1506 1507
    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
1508
    commit_t* commit = array_get_next(&(s->commits));
1509 1510 1511 1512 1513 1514
    commit->path = path;
    commit->param.mkdir.cluster = cluster;
    commit->action = ACTION_MKDIR;
}

typedef struct {
1515 1516 1517 1518 1519 1520
    /*
     * 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];
1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532
    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
1533
	const direntry_t* direntry)
1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544
{
    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
1545
	lfn->name[lfn->sequence_number * 13] = 0;
1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565
    } 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;
1566
    }
1567 1568

    if (pointer[0] & 0x40)
T
ths 已提交
1569
	lfn->len = offset + strlen((char*)lfn->name + offset);
1570

1571 1572 1573
    return 0;
}

1574 1575
/* 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
1576
	long_file_name* lfn, direntry_t* direntry)
1577
{
1578
    int i, j;
1579

1580 1581 1582 1583 1584 1585 1586 1587
    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)
1588
	    lfn->name[i] = qemu_tolower(direntry->name[i]);
1589 1590
	else
	    lfn->name[i] = direntry->name[i];
1591 1592
    }

1593 1594 1595 1596 1597 1598 1599 1600
    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)
1601
		lfn->name[i + j] = qemu_tolower(direntry->extension[j]);
1602 1603 1604 1605 1606 1607
	    else
		lfn->name[i + j] = direntry->extension[j];
	}
    } else
	lfn->name[i + j + 1] = '\0';

T
ths 已提交
1608
    lfn->len = strlen((char*)lfn->name);
1609 1610

    return 0;
1611 1612
}

1613 1614
static inline uint32_t modified_fat_get(BDRVVVFATState* s,
	unsigned int cluster)
1615
{
1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640
    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)
1641
	return 0;
1642 1643

    for (i = 0; !was_modified && i < s->sectors_per_cluster; i++)
K
Kevin Wolf 已提交
1644
	was_modified = bdrv_is_allocated(s->qcow,
1645 1646 1647
		cluster2sector(s, cluster_num) + i, 1, &dummy);

    return was_modified;
1648 1649
}

1650
static const char* get_basename(const char* path)
1651
{
1652 1653 1654 1655 1656
    char* basename = strrchr(path, '/');
    if (basename == NULL)
	return path;
    else
	return basename + 1; /* strip '/' */
1657 1658
}

1659 1660 1661 1662 1663 1664 1665 1666 1667
/*
 * 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
1668
} used_t;
1669

1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680
/*
 * 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
1681
	direntry_t* direntry, const char* path)
1682
{
1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706
    /*
     * 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
1707
    mapping_t* mapping = NULL;
1708
    const char* basename2 = NULL;
1709

1710
    vvfat_close_current_file(s);
1711

1712 1713
    /* the root directory */
    if (cluster_num == 0)
1714 1715
	return 0;

1716 1717 1718
    /* write support */
    if (s->qcow) {
	basename2 = get_basename(path);
1719

1720 1721 1722
	mapping = find_mapping_for_cluster(s, cluster_num);

	if (mapping) {
B
bellard 已提交
1723 1724
	    const char* basename;

1725 1726 1727
	    assert(mapping->mode & MODE_DELETED);
	    mapping->mode &= ~MODE_DELETED;

B
bellard 已提交
1728
	    basename = get_basename(mapping->path);
1729 1730 1731 1732 1733

	    assert(mapping->mode & MODE_NORMAL);

	    /* rename */
	    if (strcmp(basename, basename2))
1734
		schedule_rename(s, cluster_num, g_strdup(path));
1735 1736
	} else if (is_file(direntry))
	    /* new file */
1737
	    schedule_new_file(s, g_strdup(path), cluster_num);
1738
	else {
1739
            abort();
1740 1741
	    return 0;
	}
1742 1743
    }

1744 1745 1746 1747 1748 1749 1750
    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);
1751

1752 1753 1754 1755 1756 1757 1758 1759

		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 */
1760
                        abort();
1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771
			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) {
1772
                        abort();
1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792
			copy_it = 1;
		    }

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

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

		vvfat_close_current_file(s);
K
Kevin Wolf 已提交
1793 1794 1795 1796 1797 1798 1799 1800 1801 1802
                for (i = 0; i < s->sectors_per_cluster; i++) {
                    if (!bdrv_is_allocated(s->qcow, offset + i, 1, &dummy)) {
                        if (vvfat_read(s->bs, offset, s->cluster_buffer, 1)) {
                            return -1;
                        }
                        if (bdrv_write(s->qcow, offset, s->cluster_buffer, 1)) {
                            return -2;
                        }
                    }
                }
1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819
	    }
	}

	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;
    }
1820 1821
}

1822
/*
1823
 * This function looks at the modified data (qcow).
1824 1825 1826 1827 1828
 * 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)
1829
{
1830
    int ret = 0;
1831
    unsigned char* cluster = g_malloc(s->cluster_size);
A
Anthony Liguori 已提交
1832 1833
    direntry_t* direntries = (direntry_t*)cluster;
    mapping_t* mapping = find_mapping_for_cluster(s, cluster_num);
1834 1835 1836

    long_file_name lfn;
    int path_len = strlen(path);
K
Kevin Wolf 已提交
1837
    char path2[PATH_MAX + 1];
1838 1839

    assert(path_len < PATH_MAX); /* len was tested before! */
B
blueswir1 已提交
1840
    pstrcpy(path2, sizeof(path2), path);
1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853
    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))
1854
	    schedule_rename(s, cluster_num, g_strdup(path));
1855 1856
    } else
	/* new directory */
1857
	schedule_mkdir(s, cluster_num, g_strdup(path));
1858

1859 1860
    lfn_init(&lfn);
    do {
1861
	int i;
1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877
	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:
1878
            g_free(cluster);
1879 1880 1881 1882
	    return 0;
	}

	for (i = 0; i < 0x10 * s->sectors_per_cluster; i++) {
1883
	    int cluster_count = 0;
1884

1885
DLOG(fprintf(stderr, "check direntry %d:\n", i); print_direntry(direntries + i));
1886 1887 1888 1889 1890 1891 1892 1893
	    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;
1894
	    }
1895 1896 1897 1898 1899 1900 1901 1902 1903
	    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
1904 1905
		if (subret > 0 || !strcmp((char*)lfn.name, ".")
			|| !strcmp((char*)lfn.name, ".."))
1906 1907 1908 1909 1910 1911 1912 1913
		    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
1914 1915
            pstrcpy(path2 + path_len + 1, sizeof(path2) - path_len - 1,
                    (char*)lfn.name);
1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937

	    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
1938
                abort(); /* cluster_count = 0; */
1939 1940

	    ret += cluster_count;
1941 1942
	}

1943 1944
	cluster_num = modified_fat_get(s, cluster_num);
    } while(!fat_eof(s, cluster_num));
1945

1946
    g_free(cluster);
1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
    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;
1972
	s->fat2 = g_malloc(size);
1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990
	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
1991
	    mapping_t* mapping = array_get(&(s->mapping), i);
1992 1993
	    if (mapping->first_mapping_index < 0)
		mapping->mode |= MODE_DELETED;
1994
	}
1995 1996 1997 1998 1999

    used_clusters_count = check_directory_consistency(s, 0, s->path);
    if (used_clusters_count <= 0) {
	DLOG(fprintf(stderr, "problem in directory\n"));
	return 0;
2000 2001
    }

2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
    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
2031
	mapping_t* mapping = array_get(&(s->mapping), i);
2032 2033 2034 2035 2036 2037 2038 2039

#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);
2040
    }
2041 2042 2043
}

/* insert or update mapping */
A
Anthony Liguori 已提交
2044
static mapping_t* insert_mapping(BDRVVVFATState* s,
2045 2046 2047 2048 2049 2050 2051 2052 2053 2054
	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
2055 2056
    mapping_t* mapping = NULL;
    mapping_t* first_mapping = array_get(&(s->mapping), 0);
2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071

    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;
2072

A
Anthony Liguori 已提交
2073
DLOG(mapping_t* next_mapping;
2074 2075 2076 2077
assert(index + 1 >= s->mapping.next ||
((next_mapping = array_get(&(s->mapping), index + 1)) &&
 next_mapping->begin >= end)));

A
Anthony Liguori 已提交
2078
    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
2079 2080 2081 2082 2083 2084 2085 2086
	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
2087 2088
    mapping_t* mapping = array_get(&(s->mapping), mapping_index);
    mapping_t* first_mapping = array_get(&(s->mapping), 0);
2089 2090

    /* free mapping */
2091 2092 2093
    if (mapping->first_mapping_index < 0) {
        g_free(mapping->path);
    }
2094 2095 2096 2097 2098 2099 2100

    /* 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
2101
    if (s->current_mapping && first_mapping != (mapping_t*)s->mapping.pointer)
2102 2103
	s->current_mapping = array_get(&(s->mapping),
		s->current_mapping - first_mapping);
2104 2105 2106 2107

    return 0;
}

2108 2109 2110 2111
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
2112
	mapping_t* mapping = array_get(&(s->mapping), i);
2113 2114 2115 2116 2117 2118 2119
	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;
    }
}
2120

A
Anthony Liguori 已提交
2121
static direntry_t* insert_direntries(BDRVVVFATState* s,
2122
	int dir_index, int count)
2123
{
2124 2125 2126 2127
    /*
     * make room in s->directory,
     * adjust_dirindices
     */
A
Anthony Liguori 已提交
2128
    direntry_t* result = array_insert(&(s->directory), dir_index, count);
2129 2130 2131
    if (result == NULL)
	return NULL;
    adjust_dirindices(s, dir_index, count);
2132 2133 2134
    return result;
}

2135 2136 2137 2138 2139 2140 2141 2142
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;
}
2143

2144 2145 2146 2147 2148 2149 2150 2151
/*
 * 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)
2152
{
A
Anthony Liguori 已提交
2153 2154
    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185
    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
2186
	    mapping_t* next_mapping = i >= s->mapping.next ? NULL :
2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199
		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;
2200
	    next_mapping->first_mapping_index =
2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219
		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;
	}
2220

2221 2222
	cluster = c1;
    }
2223 2224 2225 2226

    return 0;
}

2227 2228
static int commit_direntries(BDRVVVFATState* s,
	int dir_index, int parent_mapping_index)
2229
{
A
Anthony Liguori 已提交
2230
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2231
    uint32_t first_cluster = dir_index == 0 ? 0 : begin_of_direntry(direntry);
A
Anthony Liguori 已提交
2232
    mapping_t* mapping = find_mapping_for_cluster(s, first_cluster);
2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258

    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++;
2259

2260 2261 2262 2263
	for (new_cluster_count = 0, c = first_cluster; !fat_eof(s, c);
		c = modified_fat_get(s, c))
	    new_cluster_count++;
    }
2264

2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283
    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;
    }
2284

2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300
    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;
	}
    }
2301

2302 2303
    return 0;
}
2304

2305 2306 2307 2308 2309
/* 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
2310
    direntry_t* direntry = array_get(&(s->directory), dir_index);
2311 2312
    uint32_t c = begin_of_direntry(direntry);
    uint32_t first_cluster = c;
A
Anthony Liguori 已提交
2313
    mapping_t* mapping = find_mapping_for_cluster(s, c);
2314
    uint32_t size = filesize_of_direntry(direntry);
2315
    char* cluster = g_malloc(s->cluster_size);
2316 2317 2318 2319 2320 2321 2322 2323 2324
    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);

2325
    fd = qemu_open(mapping->path, O_RDWR | O_CREAT | O_BINARY, 0666);
2326 2327 2328
    if (fd < 0) {
	fprintf(stderr, "Could not open %s... (%s, %d)\n", mapping->path,
		strerror(errno), errno);
2329
        g_free(cluster);
2330
	return fd;
2331
    }
2332 2333
    if (offset > 0) {
        if (lseek(fd, offset, SEEK_SET) != offset) {
2334
            qemu_close(fd);
2335 2336 2337 2338
            g_free(cluster);
            return -3;
        }
    }
2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351

    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
2352
	    (uint8_t*)cluster, (rest_size + 0x1ff) / 0x200);
2353

2354
        if (ret < 0) {
2355
            qemu_close(fd);
2356 2357 2358
            g_free(cluster);
            return ret;
        }
2359

2360
        if (write(fd, cluster, rest_size) < 0) {
2361
            qemu_close(fd);
2362 2363 2364
            g_free(cluster);
            return -2;
        }
2365 2366 2367 2368 2369

	offset += rest_size;
	c = c1;
    }

2370 2371
    if (ftruncate(fd, size)) {
        perror("ftruncate()");
2372
        qemu_close(fd);
2373
        g_free(cluster);
2374 2375
        return -4;
    }
2376
    qemu_close(fd);
2377
    g_free(cluster);
2378 2379 2380 2381 2382 2383 2384 2385 2386 2387

    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
2388
	mapping_t* mapping = array_get(&(s->mapping), i);
2389 2390 2391 2392 2393
	if (mapping->mode & MODE_DELETED) {
	    fprintf(stderr, "deleted\n");
	    continue;
	}
	assert(mapping->dir_index < s->directory.next);
A
Anthony Liguori 已提交
2394
	direntry_t* direntry = array_get(&(s->directory), mapping->dir_index);
2395 2396 2397 2398
	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);
2399 2400 2401 2402
	}
    }
}

2403 2404
/* test, if all direntries have mappings */
static void check2(BDRVVVFATState* s)
2405 2406
{
    int i;
2407
    int first_mapping = -1;
2408

2409
    for (i = 0; i < s->directory.next; i++) {
A
Anthony Liguori 已提交
2410
	direntry_t* direntry = array_get(&(s->directory), i);
2411

2412
	if (is_short_name(direntry) && begin_of_direntry(direntry)) {
A
Anthony Liguori 已提交
2413
	    mapping_t* mapping = find_mapping_for_cluster(s, begin_of_direntry(direntry));
2414 2415 2416 2417
	    assert(mapping);
	    assert(mapping->dir_index == i || is_dot(direntry));
	    assert(mapping->begin == begin_of_direntry(direntry) || is_dot(direntry));
	}
2418

2419 2420 2421
	if ((i % (0x10 * s->sectors_per_cluster)) == 0) {
	    /* cluster start */
	    int j, count = 0;
2422

2423
	    for (j = 0; j < s->mapping.next; j++) {
A
Anthony Liguori 已提交
2424
		mapping_t* mapping = array_get(&(s->mapping), j);
2425
		if (mapping->mode & MODE_DELETED)
2426
		    continue;
2427 2428 2429 2430 2431 2432 2433 2434 2435 2436
		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
2437
			    mapping_t* parent = array_get(&(s->mapping), mapping->info.dir.parent_mapping_index);
2438 2439 2440 2441
			    assert(parent->mode & MODE_DIRECTORY);
			    assert(parent->info.dir.first_dir_index < mapping->info.dir.first_dir_index);
			}
		    }
2442
		}
2443 2444 2445 2446 2447 2448 2449
	    }
	    if (count == 0)
		first_mapping = -1;
	}
    }
}
#endif
2450

2451 2452 2453
static int handle_renames_and_mkdirs(BDRVVVFATState* s)
{
    int i;
2454

2455 2456 2457
#ifdef DEBUG
    fprintf(stderr, "handle_renames\n");
    for (i = 0; i < s->commits.next; i++) {
A
Anthony Liguori 已提交
2458
	commit_t* commit = array_get(&(s->commits), i);
2459 2460 2461 2462 2463
	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
2464
	commit_t* commit = array_get(&(s->commits), i);
2465
	if (commit->action == ACTION_RENAME) {
A
Anthony Liguori 已提交
2466
	    mapping_t* mapping = find_mapping_for_cluster(s,
2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478
		    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
2479
		direntry_t* direntry = array_get(&(s->directory),
2480 2481 2482 2483 2484 2485 2486
			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
2487
			direntry_t* d = direntry + i;
2488 2489

			if (is_file(d) || (is_directory(d) && !is_dot(d))) {
A
Anthony Liguori 已提交
2490
			    mapping_t* m = find_mapping_for_cluster(s,
2491 2492
				    begin_of_direntry(d));
			    int l = strlen(m->path);
2493
			    char* new_path = g_malloc(l + diff + 1);
2494 2495 2496

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

B
blueswir1 已提交
2497 2498 2499
                            pstrcpy(new_path, l + diff + 1, mapping->path);
                            pstrcpy(new_path + l1, l + diff + 1 - l1,
                                    m->path + l2);
2500 2501

			    schedule_rename(s, m->begin, new_path);
2502
			}
2503 2504 2505
			i++;
		    } while((i % (0x10 * s->sectors_per_cluster)) != 0);
		    c = fat_get(s, c);
2506 2507 2508
		}
	    }

2509
            g_free(old_path);
2510 2511 2512
	    array_remove(&(s->commits), i);
	    continue;
	} else if (commit->action == ACTION_MKDIR) {
A
Anthony Liguori 已提交
2513
	    mapping_t* mapping;
2514 2515
	    int j, parent_path_len;

B
bellard 已提交
2516 2517 2518 2519 2520 2521 2522
#ifdef __MINGW32__
            if (mkdir(commit->path))
                return -5;
#else
            if (mkdir(commit->path, 0755))
                return -5;
#endif
2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540

	    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
2541
		mapping_t* m = array_get(&(s->mapping), j);
2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568
		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
2569
	commit_t* commit = array_get(&(s->commits), i);
2570 2571
	switch(commit->action) {
	case ACTION_RENAME: case ACTION_MKDIR:
2572
            abort();
2573 2574 2575
	    fail = -2;
	    break;
	case ACTION_WRITEOUT: {
B
Blue Swirl 已提交
2576 2577
#ifndef NDEBUG
            /* these variables are only used by assert() below */
A
Anthony Liguori 已提交
2578
	    direntry_t* entry = array_get(&(s->directory),
2579 2580
		    commit->param.writeout.dir_index);
	    uint32_t begin = begin_of_direntry(entry);
A
Anthony Liguori 已提交
2581
	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
B
Blue Swirl 已提交
2582
#endif
2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595

	    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
2596 2597
	    mapping_t* mapping = find_mapping_for_cluster(s, begin);
	    direntry_t* entry;
2598
	    int i;
2599

2600 2601 2602 2603 2604
	    /* 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;
2605 2606
	    }

2607 2608 2609 2610
	    if (i >= s->directory.next) {
		fail = -6;
		continue;
	    }
2611

2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
	    /* 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:
2633
            abort();
2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651
	}
    }
    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
2652
	    mapping_t* mapping = array_get(&(s->mapping), i);
2653
	    if (mapping->mode & MODE_DELETED) {
A
Anthony Liguori 已提交
2654
		direntry_t* entry = array_get(&(s->directory),
2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668
			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;
2669
			}
2670 2671

			for (j = 1; j < s->mapping.next; j++) {
A
Anthony Liguori 已提交
2672
			    mapping_t* m = array_get(&(s->mapping), j);
2673 2674 2675 2676 2677 2678 2679
			    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;
2680
			}
2681 2682
			remove_direntries(s, first_dir_index,
				next_dir_index - first_dir_index);
2683

2684
			deleted++;
2685
		    }
2686 2687 2688 2689
		} else {
		    if (unlink(mapping->path))
			return -4;
		    deleted++;
2690
		}
2691 2692
		DLOG(fprintf(stderr, "DELETE (%d)\n", i); print_mapping(mapping); print_direntry(entry));
		remove_mapping(s, i);
2693 2694 2695
	    }
	}
    }
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

    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);
2721
        abort();
2722 2723 2724
	return ret;
    }

2725
    /* copy FAT (with bdrv_read) */
2726 2727 2728 2729 2730 2731
    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);
2732
        abort();
2733 2734 2735 2736 2737 2738
	return ret;
    }

    ret = handle_commits(s);
    if (ret) {
	fprintf(stderr, "Error handling commits (%d)\n", ret);
2739
        abort();
2740 2741 2742 2743 2744 2745
	return ret;
    }

    ret = handle_deletes(s);
    if (ret) {
	fprintf(stderr, "Error deleting\n");
2746
        abort();
2747 2748 2749
	return ret;
    }

K
Kevin Wolf 已提交
2750 2751 2752
    if (s->qcow->drv->bdrv_make_empty) {
        s->qcow->drv->bdrv_make_empty(s->qcow);
    }
2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768

    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);
}

2769
static int vvfat_write(BlockDriverState *bs, int64_t sector_num,
2770 2771
                    const uint8_t *buf, int nb_sectors)
{
2772
    BDRVVVFATState *s = bs->opaque;
2773 2774 2775 2776
    int i, ret;

DLOG(checkpoint());

2777 2778 2779 2780 2781
    /* Check if we're operating in read-only mode */
    if (s->qcow == NULL) {
        return -EACCES;
    }

2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794
    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
2795
	mapping_t* mapping = find_mapping_for_cluster(s, i);
2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806
	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
2807
		const direntry_t* direntries;
2808 2809 2810 2811 2812 2813 2814 2815
		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;
2816
		dir_index  = mapping->dir_index +
2817
		    0x10 * (begin - mapping->begin * s->sectors_per_cluster);
A
Anthony Liguori 已提交
2818
		direntries = (direntry_t*)(buf + 0x200 * (begin - sector_num));
2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830

		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
2831
				    sizeof(direntry_t))) {
2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846
			    fprintf(stderr, "Warning: tried to write to write-protected file\n");
			    return -1;
			}
		    }
		}
	    }
	    i = mapping->end;
	} else
	    i++;
    }

    /*
     * Use qcow backend. Commit later.
     */
DLOG(fprintf(stderr, "Write to qcow backend: %d + %d\n", (int)sector_num, nb_sectors));
K
Kevin Wolf 已提交
2847
    ret = bdrv_write(s->qcow, sector_num, buf, nb_sectors);
2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865
    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;
}

2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876
static coroutine_fn int vvfat_co_write(BlockDriverState *bs, int64_t sector_num,
                                       const uint8_t *buf, int nb_sectors)
{
    int ret;
    BDRVVVFATState *s = bs->opaque;
    qemu_co_mutex_lock(&s->lock);
    ret = vvfat_write(bs, sector_num, buf, nb_sectors);
    qemu_co_mutex_unlock(&s->lock);
    return ret;
}

2877
static int64_t coroutine_fn vvfat_co_get_block_status(BlockDriverState *bs,
2878 2879 2880 2881 2882 2883 2884 2885
	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;
2886
    return 1;
2887 2888 2889 2890
}

static int write_target_commit(BlockDriverState *bs, int64_t sector_num,
	const uint8_t* buffer, int nb_sectors) {
2891
    BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
2892 2893 2894 2895
    return try_commit(s);
}

static void write_target_close(BlockDriverState *bs) {
2896
    BDRVVVFATState* s = *((BDRVVVFATState**) bs->opaque);
F
Fam Zheng 已提交
2897
    bdrv_unref(s->qcow);
2898
    g_free(s->qcow_filename);
2899 2900 2901
}

static BlockDriver vvfat_write_target = {
2902 2903 2904
    .format_name        = "vvfat_write_target",
    .bdrv_write         = write_target_commit,
    .bdrv_close         = write_target_close,
2905 2906 2907 2908
};

static int enable_write_target(BDRVVVFATState *s)
{
K
Kevin Wolf 已提交
2909 2910
    BlockDriver *bdrv_qcow;
    QEMUOptionParameter *options;
K
Kevin Wolf 已提交
2911
    int ret;
2912 2913 2914
    int size = sector2cluster(s, s->sector_count);
    s->used_clusters = calloc(size, 1);

A
Anthony Liguori 已提交
2915
    array_init(&(s->commits), sizeof(commit_t));
2916

2917
    s->qcow_filename = g_malloc(1024);
2918 2919
    ret = get_tmp_filename(s->qcow_filename, 1024);
    if (ret < 0) {
2920
        goto err;
2921
    }
K
Kevin Wolf 已提交
2922 2923 2924 2925 2926 2927

    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:");

2928 2929 2930 2931
    ret = bdrv_create(bdrv_qcow, s->qcow_filename, options);
    if (ret < 0) {
        goto err;
    }
K
Kevin Wolf 已提交
2932

2933
    s->qcow = bdrv_new("");
K
Kevin Wolf 已提交
2934

2935
    ret = bdrv_open(s->qcow, s->qcow_filename, NULL,
K
Kevin Wolf 已提交
2936 2937
            BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, bdrv_qcow);
    if (ret < 0) {
F
Fam Zheng 已提交
2938
        bdrv_unref(s->qcow);
2939
        goto err;
K
Kevin Wolf 已提交
2940
    }
2941 2942 2943 2944 2945

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

2946
    s->bs->backing_hd = bdrv_new("");
2947
    s->bs->backing_hd->drv = &vvfat_write_target;
2948
    s->bs->backing_hd->opaque = g_malloc(sizeof(void*));
2949
    *(void**)s->bs->backing_hd->opaque = s;
2950

2951
    return 0;
2952 2953 2954 2955 2956

err:
    g_free(s->qcow_filename);
    s->qcow_filename = NULL;
    return ret;
2957 2958 2959 2960 2961 2962 2963 2964 2965 2966
}

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));
2967
    g_free(s->cluster_buffer);
K
Kevin Wolf 已提交
2968 2969 2970 2971 2972

    if (s->qcow) {
        migrate_del_blocker(s->migration_blocker);
        error_free(s->migration_blocker);
    }
2973 2974
}

2975
static BlockDriver bdrv_vvfat = {
2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986
    .format_name            = "vvfat",
    .protocol_name          = "fat",
    .instance_size          = sizeof(BDRVVVFATState),

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

    .bdrv_read              = vvfat_co_read,
    .bdrv_write             = vvfat_co_write,
2987
    .bdrv_co_get_block_status = vvfat_co_get_block_status,
2988 2989
};

2990 2991 2992 2993 2994 2995 2996
static void bdrv_vvfat_init(void)
{
    bdrv_register(&bdrv_vvfat);
}

block_init(bdrv_vvfat_init);

2997
#ifdef DEBUG
2998
static void checkpoint(void) {
A
Anthony Liguori 已提交
2999
    assert(((mapping_t*)array_get(&(vvv->mapping), 0))->end == 2);
3000 3001 3002 3003
    check1(vvv);
    check2(vvv);
    assert(!vvv->current_mapping || vvv->current_fd || (vvv->current_mapping->mode & MODE_DIRECTORY));
#if 0
A
Anthony Liguori 已提交
3004
    if (((direntry_t*)vvv->directory.pointer)[1].attributes != 0xf)
3005
	fprintf(stderr, "Nonono!\n");
A
Anthony Liguori 已提交
3006 3007
    mapping_t* mapping;
    direntry_t* direntry;
3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018
    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