From c23fb11bbba90da2a5e2e121fb391a608b82afe5 Mon Sep 17 00:00:00 2001 From: Jeff Cody Date: Tue, 22 Mar 2016 23:33:41 -0400 Subject: 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: Jeff Cody Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/vpc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/block/vpc.c b/block/vpc.c index c9ebc4af30..03aee81f86 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -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; -- cgit v1.2.1