On 2015-02-11 at 22:07, Wen Congyang wrote:
Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
Signed-off-by: Gonglei <arei.gong...@huawei.com>
---
block/nbd.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
So by now to me it looks like you're using bdrv_start_replication() on
the primary VM to start transferring data through the NBD connection to
the secondary VM.
I guess this is what you were discussing with Fam and John, whether
there'd be a better way to do it by using functionality that is already
(or is about to become) part of qemu, right?
diff --git a/block/nbd.c b/block/nbd.c
index 19b9200..1ff6ecf 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -445,6 +445,58 @@ static void nbd_refresh_filename(BlockDriverState *bs)
bs->full_open_options = opts;
}
+static int nbd_start_replication(BlockDriverState *bs, int mode)
+{
+ BDRVNBDState *s = bs->opaque;
+ Error *local_err = NULL;
+ int ret;
+
+ /*
+ * TODO: support COLO_SECONDARY_MODE if we allow secondary
+ * QEMU becoming primary QEMU.
+ */
+ if (mode != COLO_PRIMARY_MODE) {
+ return -1;
Once again, I'd like -ENOTSUP more (or -EINVAL or whatever you prefer).
+ }
+
+ if (s->connected) {
+ return -1;
+ }
+
+ /* TODO: NBD client should be one child of quorum, how to verify it? */
Again, why would you care about that? Other than "It's how it's intended
to be used".
+ ret = nbd_connect_server(bs, &local_err);
+ if (local_err) {
+ error_free(local_err);
+ }
If you'd use the Error API you'd be able to propagate the error.
Max
+
+ return ret;
+}
+
+static int nbd_do_checkpoint(BlockDriverState *bs)
+{
+ BDRVNBDState *s = bs->opaque;
+
+ if (!s->connected) {
+ return -1;
+ }
+
+ return 0;
+}
+
+static int nbd_stop_replication(BlockDriverState *bs)
+{
+ BDRVNBDState *s = bs->opaque;
+
+ if (!s->connected) {
+ return -1;
+ }
+
+ nbd_client_session_close(&s->client);
+ s->connected = false;
+
+ return 0;
+}
+
static BlockDriver bdrv_nbd = {
.format_name = "nbd",
.protocol_name = "nbd",
@@ -514,6 +566,9 @@ static BlockDriver bdrv_nbd_colo = {
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
.bdrv_refresh_filename = nbd_refresh_filename,
+ .bdrv_start_replication = nbd_start_replication,
+ .bdrv_do_checkpoint = nbd_do_checkpoint,
+ .bdrv_stop_replication = nbd_stop_replication,
.has_variable_length = true,
};