[PATCH 4/6] vmdk: Don't update L2 table for zero write on zero cluster

From: Kevin Wolf <kwolf@redhat.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com
Subject: [PATCH 4/6] vmdk: Don't update L2 table for zero write on zero cluster
Date: Thu, 30 Apr 2020 15:30:05 +0200	[thread overview]
Message-ID: <20200430133007.170335-5-kwolf@redhat.com> (raw)
In-Reply-To: <20200430133007.170335-1-kwolf@redhat.com>

If a cluster is already zeroed, we don't have to call vmdk_L2update(),
which is rather slow because it flushes the image file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vmdk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index da25b8992e..dcd30f1419 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2013,7 +2013,7 @@ static int vmdk_pwritev(BlockDriverState *bs, uint64_t offset,
                     offset_in_cluster == 0 &&
                     n_bytes >= extent->cluster_sectors * BDRV_SECTOR_SIZE) {
                 n_bytes = extent->cluster_sectors * BDRV_SECTOR_SIZE;
-                if (!zero_dry_run) {
+                if (!zero_dry_run && ret != VMDK_ZEROED) {
                     /* update L2 tables */
                     if (vmdk_L2update(extent, &m_data, VMDK_GTE_ZEROED)
                             != VMDK_OK) {
-- 
2.25.3


