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From bc048d2d5f362757fa0bf51add81d92ec19ad161 Mon Sep 17 00:00:00 2001
From: Fam Zheng <famz@redhat.com>
Date: Mon, 15 Feb 2016 09:28:28 +0100
Subject: [PATCH 15/18] vmdk: Fix next_cluster_sector for compressed write

RH-Author: Fam Zheng <famz@redhat.com>
Message-id: <1455528511-9357-16-git-send-email-famz@redhat.com>
Patchwork-id: 69181
O-Subject: [RHEL-7.3 qemu-kvm PATCH 15/18] vmdk: Fix next_cluster_sector for compressed write
Bugzilla: 1299250
RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Markus Armbruster <armbru@redhat.com>

From: Radoslav Gerganov <rgerganov@vmware.com>

BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1299250

When the VMDK is streamOptimized (or compressed), the
next_cluster_sector must not be incremented by a fixed number of
sectors. Instead of this, it must be rounded up to the next consecutive
sector. Fixing this results in much smaller compressed images.

Signed-off-by: Radoslav Gerganov <rgerganov@vmware.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 3efffc3292d94271a15b1606b4a56adf6c6f04ed)
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 block/vmdk.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index cb5255c..7009660 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1333,8 +1333,12 @@ static int vmdk_write_extent(VmdkExtent *extent, int64_t cluster_offset,
 
     write_end_sector = DIV_ROUND_UP(write_offset + write_len, BDRV_SECTOR_SIZE);
 
-    extent->next_cluster_sector = MAX(extent->next_cluster_sector,
-                                      write_end_sector);
+    if (extent->compressed) {
+        extent->next_cluster_sector = write_end_sector;
+    } else {
+        extent->next_cluster_sector = MAX(extent->next_cluster_sector,
+                                          write_end_sector);
+    }
 
     if (ret != write_len) {
         ret = ret < 0 ? ret : -EIO;
-- 
1.8.3.1