From f03758aa88454cd2efe72b7623b855331c5ee22c Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Fri, 1 Nov 2013 14:23:15 +0100 Subject: [PATCH 27/81] qcow2: Restore total_sectors value in save_vmstate RH-Author: Max Reitz Message-id: <1383315797-30938-2-git-send-email-mreitz@redhat.com> Patchwork-id: 55216 O-Subject: [RHEL-7.0 qemu-kvm PATCH 1/3] qcow2: Restore total_sectors value in save_vmstate Bugzilla: 1025740 RH-Acked-by: Kevin Wolf RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Alex Williamson BZ: 1025740 Since df2a6f29a5, bdrv_co_do_writev increases the total_sectors value of a growable block devices on writes after the current end. This leads to the virtual disk apparently growing in qcow2_save_vmstate, which in turn affects the disk size captured by the internal snapshot taken directly afterwards through e.g. the HMP savevm command. Such a "grown" snapshot cannot be loaded after reopening the qcow2 image, since its disk size differs from the actual virtual disk size (writing a VM state does not actually increase the virtual disk size). Fix this by restoring total_sectors at the end of qcow2_save_vmstate. Signed-off-by: Max Reitz Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf (cherry picked from commit eedff66f21e542650d895801549ce05ac108278b) Signed-off-by: Max Reitz --- block/qcow2.c | 6 ++++++ 1 file changed, 6 insertions(+) Signed-off-by: Miroslav Rezanina --- block/qcow2.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 8e894b9..f4adf35 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1716,6 +1716,7 @@ static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) { BDRVQcowState *s = bs->opaque; + int64_t total_sectors = bs->total_sectors; int growable = bs->growable; int ret; @@ -1724,6 +1725,11 @@ static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov); bs->growable = growable; + /* bdrv_co_do_writev will have increased the total_sectors value to include + * the VM state - the VM state is however not an actual part of the block + * device, therefore, we need to restore the old value. */ + bs->total_sectors = total_sectors; + return ret; } -- 1.7.1