| Message ID | 1466086108-24868-28-git-send-email-kwolf@redhat.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/block.c b/block.c index b350794..8104225 100644 --- a/block.c +++ b/block.c @@ -684,6 +684,10 @@ static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options, /* For temporary files, unconditional cache=unsafe is fine */ qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off"); qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on"); + + /* aio=native doesn't work for cache.direct=off, so disable it for the + * temporary snapshot */ + *child_flags &= ~BDRV_O_NATIVE_AIO; } /*
snapshot=on creates a temporary overlay that is always opened with cache=unsafe (the cache mode specified by the user is only for the actual image file and its children). This means that we must not inherit the BDRV_O_NATIVE_AIO flag for the temporary overlay because trying to use Linux AIO with cache=unsafe results in an error. Reproducer without this patch: $ x86_64-softmmu/qemu-system-x86_64 -drive file=/tmp/test.qcow2,cache=none,aio=native,snapshot=on qemu-system-x86_64: -drive file=/tmp/test.qcow2,cache=none,aio=native,snapshot=on: aio=native was specified, but it requires cache.direct=on, which was not specified. Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- block.c | 4 ++++ 1 file changed, 4 insertions(+)