From: Jeff Cody <jc...@redhat.com>
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 <jc...@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
block/vpc.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/block/vpc.c b/block/vpc.c
index c9ebc4a..03aee81 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;
--
1.8.3.1
