On 2018-09-13 10:54, Fam Zheng wrote:
On Thu, 09/13 10:31, yuchen...@synology.com wrote:
From: yuchenlin <yuchen...@synology.com>
There is a rare case which the size of last compressed cluster
is larger than the cluster size, which will cause the file is
not aligned at the sector boundary.
The code looks good to me. Can you also explain why it is important to
align
file size to sector boundary in the comment?
Fam
In my opinion, there are three reasons to do it. First, if vmdk doesn't
align at the sector boundary, there may be many undefined behaviors,
such as in vbox it will show VMDK: Compressed image is corrupted
'88-disk1.vmdk' (VERR_ZIP_CORRUPTED) when we try to import an ova with
unaligned vmdk. Second, all the cluster_sector is aligned
to sector, the last one should be like this, too. Third, it ease reading
with sector based I/Os.
What do you think?
yuchenlin
Signed-off-by: yuchenlin <yuchen...@synology.com>
---
v1 -> v2:
* Add more detail comment.
* Add QEMU_ALIGN_UP to show the intention more clearly.
* Add newline in the end of bdrv_truncate.
thanks
block/vmdk.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/block/vmdk.c b/block/vmdk.c
index a9d0084e36..2c9e86d98f 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1698,6 +1698,27 @@ static int coroutine_fn
vmdk_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, QEMUIOVector *qiov)
{
+ if (bytes == 0) {
+ /* The caller will write bytes 0 to signal EOF.
+ * When receive it, we align EOF to a sector boundary. */
+ BDRVVmdkState *s = bs->opaque;
+ int i, ret;
+ int64_t length;
+
+ for (i = 0; i < s->num_extents; i++) {
+ length = bdrv_getlength(s->extents[i].file->bs);
+ if (length < 0) {
+ return length;
+ }
+ length = QEMU_ALIGN_UP(length, BDRV_SECTOR_SIZE);
+ ret = bdrv_truncate(s->extents[i].file, length,
+ PREALLOC_MODE_OFF, NULL);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+ return 0;
+ }
return vmdk_co_pwritev(bs, offset, bytes, qiov, 0);
}
--
2.18.0
