vmdk: use heap allocation for whole_grain

We should never grow the stack beyond 1 MB, otherwise we'll fall off the
end.  Thread stacks and coroutine stacks (1 MB) do not grow.
get_cluster_offset() allocates a big stack offset, it will fail for big
cluster images, change to heap allocated buffer.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng 2013-08-06 15:44:54 +08:00 committed by Kevin Wolf
parent 2c43e43c8c
commit bf81507de3

View file

@ -842,16 +842,17 @@ static int get_whole_cluster(BlockDriverState *bs,
uint64_t offset,
bool allocate)
{
/* 128 sectors * 512 bytes each = grain size 64KB */
uint8_t whole_grain[extent->cluster_sectors * 512];
int ret = VMDK_OK;
uint8_t *whole_grain = NULL;
/* we will be here if it's first write on non-exist grain(cluster).
* try to read from parent image, if exist */
if (bs->backing_hd) {
int ret;
whole_grain =
qemu_blockalign(bs, extent->cluster_sectors << BDRV_SECTOR_BITS);
if (!vmdk_is_cid_valid(bs)) {
return VMDK_ERROR;
ret = VMDK_ERROR;
goto exit;
}
/* floor offset to cluster */
@ -859,17 +860,21 @@ static int get_whole_cluster(BlockDriverState *bs,
ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain,
extent->cluster_sectors);
if (ret < 0) {
return VMDK_ERROR;
ret = VMDK_ERROR;
goto exit;
}
/* Write grain only into the active image */
ret = bdrv_write(extent->file, cluster_offset, whole_grain,
extent->cluster_sectors);
if (ret < 0) {
return VMDK_ERROR;
ret = VMDK_ERROR;
goto exit;
}
}
return VMDK_OK;
exit:
qemu_vfree(whole_grain);
return ret;
}
static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data)