Commit c23fb11b authored by Jeff Cody's avatar Jeff Cody Committed by Kevin Wolf
Browse files

block/vpc: Use the correct max sector count for VHD images 



The old VHD_MAX_SECTORS value is incorrect, and is a throwback
to the CHS calculations.  The VHD specification allows images up to 2040
GiB, which (using 512 byte sectors) corresponds to a maximum number of
sectors of 0xff000000, rather than the old value of 0xfe0001ff.

Update VHD_MAX_SECTORS to reflect the correct value.

Also, update comment references to the actual size limit, and correct
one compare so that we can have sizes up to the limit.

Signed-off-by: default avatarJeff Cody <jcody@redhat.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent bab246db

block/vpc.c

+5 −5
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ enum vhd_type { 
#define VHD_CHS_MAX_H   16

#define VHD_CHS_MAX_S   255



#define VHD_MAX_SECTORS       (65535LL * 255 * 255)

#define VHD_MAX_SECTORS       0xff000000    /* 2040 GiB max image size */

#define VHD_MAX_GEOMETRY      (VHD_CHS_MAX_C * VHD_CHS_MAX_H * VHD_CHS_MAX_S)



#define VPC_OPT_FORCE_SIZE "force_size"
@@ -317,8 +317,8 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, 
                                        BDRV_SECTOR_SIZE;

    }



    /* Allow a maximum disk size of approximately 2 TB */

    if (bs->total_sectors >= VHD_MAX_SECTORS) {

    /* Allow a maximum disk size of 2040 GiB */

    if (bs->total_sectors > VHD_MAX_SECTORS) {

        ret = -EFBIG;

        goto fail;

    }
@@ -722,7 +722,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs, 
 * Note that the geometry doesn't always exactly match total_sectors but

 * may round it down.

 *

 * Returns 0 on success, -EFBIG if the size is larger than ~2 TB. Override

 * Returns 0 on success, -EFBIG if the size is larger than 2040 GiB. Override

 * the hardware EIDE and ATA-2 limit of 16 heads (max disk size of 127 GB)

 * and instead allow up to 255 heads.

 */
@@ -927,7 +927,7 @@ static int vpc_create(const char *filename, QemuOpts *opts, Error **errp) 


    if ((int64_t)cyls * heads * secs_per_cyl == VHD_MAX_GEOMETRY) {

        total_sectors = total_size / BDRV_SECTOR_SIZE;

        /* Allow a maximum disk size of approximately 2 TB */

        /* Allow a maximum disk size of 2040 GiB */

        if (total_sectors > VHD_MAX_SECTORS) {

            error_setg(errp, "Disk size is too large, max size is 2040 GiB");

            ret = -EFBIG;