diff options
| author | Max Reitz <mreitz@redhat.com> | 2013-10-20 21:52:35 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2013-10-24 11:50:51 +0200 |
| commit | 6e13610aa454beba52944e8df6d93158d68ab911 (patch) | |
| tree | 5166de3fc9a399df930e53091e2aeaf5c18b532f | |
| parent | eedff66f21e542650d895801549ce05ac108278b (diff) | |
| download | qemu-6e13610aa454beba52944e8df6d93158d68ab911.tar.gz | |
qcow2: Unset zero_beyond_eof in save_vmstate
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>
| -rw-r--r-- | block/qcow2.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 4a3e8b45f8..01269f9264 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 |