Am 03.02.2012 01:16, schrieb Charles Arnold:
> Next version of the patch with fixes, cleanups, and suggestions.
> - Charles
>
>
> The Virtual Hard Disk Image Format Specification allows for three
> types of hard disk formats, Fixed, Dynamic, and Differencing. Qemu
> currently only supports Dynamic disks. This patch adds support for
> the Fixed Disk format.
>
> Usage:
> Example 1: qemu-img create -f vpc -o type=fixed <filename> [size]
> Example 2: qemu-img convert -O vpc -o type=fixed <input filename> <output
> filename>
>
> While it is also allowed to specify '-o type=dynamic', the default disk type
> remains Dynamic and is what is used when the type is left unspecified.
>
> Signed-off-by: Charles Arnold <carn...@suse.com>
>
> diff --git a/block/vpc.c b/block/vpc.c
> index 89a5ee2..d9a1c44 100644
> --- a/block/vpc.c
> +++ b/block/vpc.c
> @@ -161,13 +161,27 @@ static int vpc_open(BlockDriverState *bs, int flags)
> uint8_t buf[HEADER_SIZE];
> uint32_t checksum;
> int err = -1;
> + int disk_type = VHD_DYNAMIC;
>
> if (bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE)
> goto fail;
>
> footer = (struct vhd_footer*) s->footer_buf;
> - if (strncmp(footer->creator, "conectix", 8))
> - goto fail;
> + if (strncmp(footer->creator, "conectix", 8)) {
> + int64_t offset = bdrv_getlength(bs->file);
> + if (offset < HEADER_SIZE) {
> + goto fail;
> + }
> + /* If a fixed disk, the footer is found only at the end of the file
> */
> + if (bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf,
> HEADER_SIZE)
> + != HEADER_SIZE) {
> + goto fail;
> + }
> + if (strncmp(footer->creator, "conectix", 8)) {
> + goto fail;
> + }
> + disk_type = VHD_FIXED;
> + }
>
> checksum = be32_to_cpu(footer->checksum);
> footer->checksum = 0;
> @@ -186,49 +200,54 @@ static int vpc_open(BlockDriverState *bs, int flags)
> goto fail;
> }
>
> - if (bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf,
> HEADER_SIZE)
> - != HEADER_SIZE)
> - goto fail;
> -
> - dyndisk_header = (struct vhd_dyndisk_header*) buf;
> + if (disk_type == VHD_DYNAMIC) {
> + if (bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf,
> + HEADER_SIZE) != HEADER_SIZE) {
> + goto fail;
> + }
>
> - if (strncmp(dyndisk_header->magic, "cxsparse", 8))
> - goto fail;
> + dyndisk_header = (struct vhd_dyndisk_header *) buf;
>
> + if (strncmp(dyndisk_header->magic, "cxsparse", 8)) {
> + goto fail;
> + }
>
> - s->block_size = be32_to_cpu(dyndisk_header->block_size);
> - s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511;
> + s->block_size = be32_to_cpu(dyndisk_header->block_size);
> + s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511;
>
> - s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries);
> - s->pagetable = g_malloc(s->max_table_entries * 4);
> + s->max_table_entries =
> be32_to_cpu(dyndisk_header->max_table_entries);
> + s->pagetable = g_malloc(s->max_table_entries * 4);
>
> - s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);
> - if (bdrv_pread(bs->file, s->bat_offset, s->pagetable,
> - s->max_table_entries * 4) != s->max_table_entries * 4)
> - goto fail;
> + s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);
> + if (bdrv_pread(bs->file, s->bat_offset, s->pagetable,
> + s->max_table_entries * 4) != s->max_table_entries * 4) {
> + goto fail;
> + }
>
> - s->free_data_block_offset =
> - (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511;
> + s->free_data_block_offset =
> + (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511;
>
> - for (i = 0; i < s->max_table_entries; i++) {
> - be32_to_cpus(&s->pagetable[i]);
> - if (s->pagetable[i] != 0xFFFFFFFF) {
> - int64_t next = (512 * (int64_t) s->pagetable[i]) +
> - s->bitmap_size + s->block_size;
> + for (i = 0; i < s->max_table_entries; i++) {
> + be32_to_cpus(&s->pagetable[i]);
> + if (s->pagetable[i] != 0xFFFFFFFF) {
> + int64_t next = (512 * (int64_t) s->pagetable[i]) +
> + s->bitmap_size + s->block_size;
>
> - if (next> s->free_data_block_offset)
> - s->free_data_block_offset = next;
> + if (next > s->free_data_block_offset) {
> + s->free_data_block_offset = next;
> + }
> + }
> }
> - }
>
> - s->last_bitmap_offset = (int64_t) -1;
> + s->last_bitmap_offset = (int64_t) -1;
>
> #ifdef CACHE
> - s->pageentry_u8 = g_malloc(512);
> - s->pageentry_u32 = s->pageentry_u8;
> - s->pageentry_u16 = s->pageentry_u8;
> - s->last_pagetable = -1;
> + s->pageentry_u8 = g_malloc(512);
> + s->pageentry_u32 = s->pageentry_u8;
> + s->pageentry_u16 = s->pageentry_u8;
> + s->last_pagetable = -1;
> #endif
> + }
>
> qemu_co_mutex_init(&s->lock);
>
> @@ -395,7 +414,11 @@ static int vpc_read(BlockDriverState *bs, int64_t
> sector_num,
> int ret;
> int64_t offset;
> int64_t sectors, sectors_per_block;
> + struct vhd_footer *footer = (struct vhd_footer *) s->footer_buf;
>
> + if (cpu_to_be32(footer->type) == VHD_FIXED) {
> + return bdrv_read(bs->file, sector_num, buf, nb_sectors);
> + }
> while (nb_sectors > 0) {
> offset = get_sector_offset(bs, sector_num, 0);
>
> @@ -440,7 +463,11 @@ static int vpc_write(BlockDriverState *bs, int64_t
> sector_num,
> int64_t offset;
> int64_t sectors, sectors_per_block;
> int ret;
> + struct vhd_footer *footer = (struct vhd_footer *) s->footer_buf;
>
> + if (cpu_to_be32(footer->type) == VHD_FIXED) {
> + return bdrv_write(bs->file, sector_num, buf, nb_sectors);
> + }
> while (nb_sectors > 0) {
> offset = get_sector_offset(bs, sector_num, 1);
>
> @@ -533,70 +560,14 @@ static int calculate_geometry(int64_t total_sectors,
> uint16_t* cyls,
> return 0;
> }
>
> -static int vpc_create(const char *filename, QEMUOptionParameter *options)
> +static int create_dynamic_disk(int fd, uint8_t *buf, int64_t total_sectors)
> {
> - uint8_t buf[1024];
> - struct vhd_footer* footer = (struct vhd_footer*) buf;
> struct vhd_dyndisk_header* dyndisk_header =
> (struct vhd_dyndisk_header*) buf;
> - int fd, i;
> - uint16_t cyls = 0;
> - uint8_t heads = 0;
> - uint8_t secs_per_cyl = 0;
> size_t block_size, num_bat_entries;
> - int64_t total_sectors = 0;
> + int i;
> int ret = -EIO;
>
> - // Read out options
> - total_sectors = get_option_parameter(options, BLOCK_OPT_SIZE)->value.n /
> - BDRV_SECTOR_SIZE;
> -
> - // Create the file
> - fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
> - if (fd < 0)
> - return -EIO;
> -
> - /* Calculate matching total_size and geometry. Increase the number of
> - sectors requested until we get enough (or fail). */
> - for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) {
> - if (calculate_geometry(total_sectors + i,
> - &cyls, &heads, &secs_per_cyl)) {
> - ret = -EFBIG;
> - goto fail;
> - }
> - }
> - total_sectors = (int64_t) cyls * heads * secs_per_cyl;
> -
> - // Prepare the Hard Disk Footer
> - memset(buf, 0, 1024);
> -
> - memcpy(footer->creator, "conectix", 8);
> - // TODO Check if "qemu" creator_app is ok for VPC
> - memcpy(footer->creator_app, "qemu", 4);
> - memcpy(footer->creator_os, "Wi2k", 4);
> -
> - footer->features = be32_to_cpu(0x02);
> - footer->version = be32_to_cpu(0x00010000);
> - footer->data_offset = be64_to_cpu(HEADER_SIZE);
> - footer->timestamp = be32_to_cpu(time(NULL) - VHD_TIMESTAMP_BASE);
> -
> - // Version of Virtual PC 2007
> - footer->major = be16_to_cpu(0x0005);
> - footer->minor =be16_to_cpu(0x0003);
> -
> - footer->orig_size = be64_to_cpu(total_sectors * 512);
> - footer->size = be64_to_cpu(total_sectors * 512);
> -
> - footer->cyls = be16_to_cpu(cyls);
> - footer->heads = heads;
> - footer->secs_per_cyl = secs_per_cyl;
> -
> - footer->type = be32_to_cpu(VHD_DYNAMIC);
> -
> - // TODO uuid is missing
> -
> - footer->checksum = be32_to_cpu(vpc_checksum(buf, HEADER_SIZE));
> -
> // Write the footer (twice: at the beginning and at the end)
> block_size = 0x200000;
> num_bat_entries = (total_sectors + block_size / 512) / (block_size /
> 512);
> @@ -624,7 +595,6 @@ static int vpc_create(const char *filename,
> QEMUOptionParameter *options)
> }
> }
>
> -
> // Prepare the Dynamic Disk Header
> memset(buf, 0, 1024);
>
> @@ -653,6 +623,130 @@ static int vpc_create(const char *filename,
> QEMUOptionParameter *options)
> ret = 0;
>
> fail:
> + return ret;
> +}
> +
> +static int create_fixed_disk(int fd, uint8_t *buf, int64_t total_size)
> +{
> + int ret = -EIO;
> +
> + /* Add footer to total size */
> + total_size += 512;
> + if (ftruncate(fd, total_size) != 0) {
> + ret = -errno;
> + goto fail;
> + }
> + if (lseek(fd, -512, SEEK_END) < 0) {
> + goto fail;
> + }
> + if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) {
> + goto fail;
> + }
> +
> + ret = 0;
> +
> + fail:
> + return ret;
> +}
> +
> +static int vpc_create(const char *filename, QEMUOptionParameter *options)
> +{
> + uint8_t buf[1024];
> + struct vhd_footer *footer = (struct vhd_footer *) buf;
> + QEMUOptionParameter *disk_type_param;
> + int fd, i;
> + uint16_t cyls = 0;
> + uint8_t heads = 0;
> + uint8_t secs_per_cyl = 0;
> + int64_t total_sectors;
> + int64_t total_size;
> + int disk_type;
> + int ret = -EIO;
> +
> + /* Read out options */
> + total_size = get_option_parameter(options, BLOCK_OPT_SIZE)->value.n;
> +
> + disk_type_param = get_option_parameter(options, BLOCK_OPT_SUBFMT);
> + if (disk_type_param && disk_type_param->value.s) {
> + if (!strcmp(disk_type_param->value.s, "dynamic")) {
> + disk_type = VHD_DYNAMIC;
> + } else if (!strcmp(disk_type_param->value.s, "fixed")) {
> + disk_type = VHD_FIXED;
> + } else {
> + return -EINVAL;
> + }
> + } else {
> + disk_type = VHD_DYNAMIC;
> + }
> +
> + /* Create the file */
> + fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
> + if (fd < 0) {
> + return -EIO;
> + }
> +
> + total_sectors = total_size / BDRV_SECTOR_SIZE;
> + if (disk_type == VHD_DYNAMIC) {
> + /* Calculate matching total_size and geometry. Increase the number of
> + sectors requested until we get enough (or fail). */
> + for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl;
> + i++) {
> + if (calculate_geometry(total_sectors + i,
> + &cyls, &heads, &secs_per_cyl)) {
> + goto fail;
Somehow you lost the ret = -EFBIG here.
Otherwise the patch looks good enough for me.
Kevin
