block: Accept node-name for blockdev-snapshot-internal-sync

In order to remove the necessity to use BlockBackend names in the
external API, we want to allow node-names everywhere. This converts
blockdev-snapshot-internal-sync to accept a node-name without lifting
the restriction that we're operating at a root node.

In case of an invalid device name, the command returns the GenericError
error class now instead of DeviceNotFound, because this is what
qmp_get_root_bs() returns.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

1 files changed, 3 insertions, 12 deletions

diff --git a/blockdev.c b/blockdev.c
index 9feffcd088..f775bbdf9d 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1511,7 +1511,6 @@ static void internal_snapshot_prepare(BlkActionState *common,
     Error *local_err = NULL;
     const char *device;
     const char *name;
-    BlockBackend *blk;
     BlockDriverState *bs;
     QEMUSnapshotInfo old_sn, *sn;
     bool ret;
@@ -1534,23 +1533,15 @@ static void internal_snapshot_prepare(BlkActionState *common,
         return;
     }
 
-    blk = blk_by_name(device);
-    if (!blk) {
-        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
-                  "Device '%s' not found", device);
+    bs = qmp_get_root_bs(device, errp);
+    if (!bs) {
         return;
     }
 
     /* AioContext is released in .clean() */
-    state->aio_context = blk_get_aio_context(blk);
+    state->aio_context = bdrv_get_aio_context(bs);
     aio_context_acquire(state->aio_context);
 
-    if (!blk_is_available(blk)) {
-        error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
-        return;
-    }
-    bs = blk_bs(blk);
-
     state->bs = bs;
     bdrv_drained_begin(bs);