| From 3ab144fe22a867a0ffcce396302b62b0f2ac4c29 Mon Sep 17 00:00:00 2001 |
| From: Max Reitz <mreitz@redhat.com> |
| Date: Fri, 1 Nov 2013 14:23:16 +0100 |
| Subject: [PATCH 28/81] qcow2: Unset zero_beyond_eof in save_vmstate |
| |
| RH-Author: Max Reitz <mreitz@redhat.com> |
| Message-id: <1383315797-30938-3-git-send-email-mreitz@redhat.com> |
| Patchwork-id: 55217 |
| O-Subject: [RHEL-7.0 qemu-kvm PATCH 2/3] qcow2: Unset zero_beyond_eof in save_vmstate |
| Bugzilla: 1025740 |
| RH-Acked-by: Kevin Wolf <kwolf@redhat.com> |
| RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com> |
| RH-Acked-by: Alex Williamson <alex.williamson@redhat.com> |
| |
| BZ: 1025740 |
| |
| Saving the VM state is done using bdrv_pwrite. This function may perform |
| a read-modify-write, which in this case results in data being read from |
| beyond the end of the virtual disk. Since we are actually trying to |
| access an area which is not a part of the virtual disk, zero_beyond_eof |
| has to be set to false before performing the partial write, otherwise |
| the VM state may become corrupted. |
| |
| Signed-off-by: Max Reitz <mreitz@redhat.com> |
| Reviewed-by: Eric Blake <eblake@redhat.com> |
| Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
| (cherry picked from commit 6e13610aa454beba52944e8df6d93158d68ab911) |
| |
| Signed-off-by: Max Reitz <mreitz@redhat.com> |
| |
| block/qcow2.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> |
| |
| block/qcow2.c | 3 +++ |
| 1 files changed, 3 insertions(+), 0 deletions(-) |
| |
| diff --git a/block/qcow2.c b/block/qcow2.c |
| index f4adf35..c2728c9 100644 |
| |
| |
| @@ -1718,12 +1718,15 @@ static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, |
| BDRVQcowState *s = bs->opaque; |
| int64_t total_sectors = bs->total_sectors; |
| int growable = bs->growable; |
| + bool zero_beyond_eof = bs->zero_beyond_eof; |
| int ret; |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); |
| bs->growable = 1; |
| + bs->zero_beyond_eof = false; |
| ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov); |
| bs->growable = growable; |
| + bs->zero_beyond_eof = zero_beyond_eof; |
| |
| /* 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 |
| -- |
| 1.7.1 |
| |