qmp: Add blockdev-mirror command

This will start a mirror job from a named device to another named
device, its relation with drive-mirror is similar with blockdev-backup
to drive-backup.

In blockdev-mirror, the target node should be prepared by blockdev-add,
which will be responsible for assigning a name to the new node, so
we don't have 'node-name' parameter.

Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1450932306-13717-5-git-send-email-famz@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/blockdev.c b/blockdev.c
index f42e1713e9..2df0c6d366 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3345,6 +3345,10 @@ static void blockdev_mirror_common(BlockDriverState *bs,
     if (bdrv_op_is_blocked(target, BLOCK_OP_TYPE_MIRROR_TARGET, errp)) {
         return;
     }
+    if (target->blk) {
+        error_setg(errp, "Cannot mirror to an attached block device");
+        return;
+    }
 
     if (!bs->backing && sync == MIRROR_SYNC_MODE_TOP) {
         sync = MIRROR_SYNC_MODE_FULL;
@@ -3518,6 +3522,64 @@ out:
     aio_context_release(aio_context);
 }
 
+void qmp_blockdev_mirror(const char *device, const char *target,
+                         bool has_replaces, const char *replaces,
+                         MirrorSyncMode sync,
+                         bool has_speed, int64_t speed,
+                         bool has_granularity, uint32_t granularity,
+                         bool has_buf_size, int64_t buf_size,
+                         bool has_on_source_error,
+                         BlockdevOnError on_source_error,
+                         bool has_on_target_error,
+                         BlockdevOnError on_target_error,
+                         Error **errp)
+{
+    BlockDriverState *bs;
+    BlockBackend *blk;
+    BlockDriverState *target_bs;
+    AioContext *aio_context;
+    Error *local_err = NULL;
+
+    blk = blk_by_name(device);
+    if (!blk) {
+        error_setg(errp, "Device '%s' not found", device);
+        return;
+    }
+    bs = blk_bs(blk);
+
+    if (!bs) {
+        error_setg(errp, "Device '%s' has no media", device);
+        return;
+    }
+
+    target_bs = bdrv_lookup_bs(target, target, errp);
+    if (!target_bs) {
+        return;
+    }
+
+    aio_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(aio_context);
+
+    bdrv_ref(target_bs);
+    bdrv_set_aio_context(target_bs, aio_context);
+
+    blockdev_mirror_common(bs, target_bs,
+                           has_replaces, replaces, sync,
+                           has_speed, speed,
+                           has_granularity, granularity,
+                           has_buf_size, buf_size,
+                           has_on_source_error, on_source_error,
+                           has_on_target_error, on_target_error,
+                           true, true,
+                           &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        bdrv_unref(target_bs);
+    }
+
+    aio_context_release(aio_context);
+}
+
 /* Get the block job for a given device name and acquire its AioContext */
 static BlockJob *find_block_job(const char *device, AioContext **aio_context,
                                 Error **errp)