[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL 03/30] qcow2: Unset zero_beyond_eof in save_vmstate
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 03/30] qcow2: Unset zero_beyond_eof in save_vmstate |
Date: |
Thu, 31 Oct 2013 16:48:17 +0100 |
From: Max Reitz <address@hidden>
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 <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/block/qcow2.c b/block/qcow2.c
index 4a3e8b4..01269f9 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1941,12 +1941,15 @@ 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
--
1.8.1.4
- [Qemu-devel] [PULL v2 00/30] Block patches, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 02/30] qcow2: Restore total_sectors value in save_vmstate, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 04/30] qemu-img: add special exit code if bdrv_check is not supported, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 05/30] block/vpc: check that the image has not been truncated, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 01/30] qapi: fix documentation example, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 03/30] qcow2: Unset zero_beyond_eof in save_vmstate,
Kevin Wolf <=
- [Qemu-devel] [PULL 06/30] qemu-iotests: Test for loading VM state from qcow2, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 07/30] qcow2: Flush image after creation, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 09/30] ide-test: Check what happens with bus mastering disabled, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 10/30] tests: Multiboot mmap test case, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 11/30] block: Don't copy backing file name on error, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 08/30] exec: Fix bounce buffer allocation in address_space_map(), Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 12/30] sheepdog: explicitly set copies as type uint8_t, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 14/30] ahci: fix win7 hang on boot, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 13/30] sheepdog: pass copy_policy in the request, Kevin Wolf, 2013/10/31
- [Qemu-devel] [PULL 15/30] block: Disable BDRV_O_COPY_ON_READ for the backing file, Kevin Wolf, 2013/10/31