rbd: Fix to cleanly reject -drive without pool or image

[mirror_qemu.git] / blockdev.c

diff --git a/blockdev.c b/blockdev.c
index e592180b6286c7ac5817236c8c21322b02365d76..c5b2c2c209223d6521261df2c265d1f929529ab2 100644 (file)
--- a/blockdev.c
+++ b/blockdev.c
@@ -1614,6 +1614,7 @@ typedef struct ExternalSnapshotState {
     BlockDriverState *old_bs;
     BlockDriverState *new_bs;
     AioContext *aio_context;
+    bool overlay_appended;
 } ExternalSnapshotState;
 
 static void external_snapshot_prepare(BlkActionState *common,
@@ -1768,7 +1769,19 @@ static void external_snapshot_prepare(BlkActionState *common,
 
     if (!state->new_bs->drv->supports_backing) {
         error_setg(errp, "The snapshot does not support backing images");
+        return;
     }
+
+    /* This removes our old bs and adds the new bs. This is an operation that
+     * can fail, so we need to do it in .prepare; undoing it for abort is
+     * always possible. */
+    bdrv_ref(state->new_bs);
+    bdrv_append(state->new_bs, state->old_bs, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+    state->overlay_appended = true;
 }
 
 static void external_snapshot_commit(BlkActionState *common)
@@ -1778,8 +1791,6 @@ static void external_snapshot_commit(BlkActionState *common)
 
     bdrv_set_aio_context(state->new_bs, state->aio_context);
 
-    /* This removes our old bs and adds the new bs */
-    bdrv_append(state->new_bs, state->old_bs);
     /* We don't need (or want) to use the transactional
      * bdrv_reopen_multiple() across all the entries at once, because we
      * don't want to abort all of them if one of them fails the reopen */
@@ -1794,7 +1805,9 @@ static void external_snapshot_abort(BlkActionState *common)
     ExternalSnapshotState *state =
                              DO_UPCAST(ExternalSnapshotState, common, common);
     if (state->new_bs) {
-        bdrv_unref(state->new_bs);
+        if (state->overlay_appended) {
+            bdrv_replace_node(state->new_bs, state->old_bs, &error_abort);
+        }
     }
 }
 
@@ -1805,6 +1818,7 @@ static void external_snapshot_clean(BlkActionState *common)
     if (state->aio_context) {
         bdrv_drained_end(state->old_bs);
         aio_context_release(state->aio_context);
+        bdrv_unref(state->new_bs);
     }
 }
 
@@ -2033,7 +2047,9 @@ static void block_dirty_bitmap_clear_abort(BlkActionState *common)
     BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState,
                                              common, common);
 
-    bdrv_undo_clear_dirty_bitmap(state->bitmap, state->backup);
+    if (state->backup) {
+        bdrv_undo_clear_dirty_bitmap(state->bitmap, state->backup);
+    }
 }
 
 static void block_dirty_bitmap_clear_commit(BlkActionState *common)
@@ -3032,6 +3048,7 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device,
                       bool has_top, const char *top,
                       bool has_backing_file, const char *backing_file,
                       bool has_speed, int64_t speed,
+                      bool has_filter_node_name, const char *filter_node_name,
                       Error **errp)
 {
     BlockDriverState *bs;
@@ -3047,6 +3064,9 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device,
     if (!has_speed) {
         speed = 0;
     }
+    if (!has_filter_node_name) {
+        filter_node_name = NULL;
+    }
 
     /* Important Note:
      *  libvirt relies on the DeviceNotFound error class in order to probe for
@@ -3121,8 +3141,8 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device,
             goto out;
         }
         commit_active_start(has_job_id ? job_id : NULL, bs, base_bs,
-                            BLOCK_JOB_DEFAULT, speed, on_error, NULL, NULL,
-                            &local_err, false);
+                            BLOCK_JOB_DEFAULT, speed, on_error,
+                            filter_node_name, NULL, NULL, &local_err, false);
     } else {
         BlockDriverState *overlay_bs = bdrv_find_overlay(bs, top_bs);
         if (bdrv_op_is_blocked(overlay_bs, BLOCK_OP_TYPE_COMMIT_TARGET, errp)) {
@@ -3130,7 +3150,7 @@ void qmp_block_commit(bool has_job_id, const char *job_id, const char *device,
         }
         commit_start(has_job_id ? job_id : NULL, bs, base_bs, top_bs, speed,
                      on_error, has_backing_file ? backing_file : NULL,
-                     &local_err);
+                     filter_node_name, &local_err);
     }
     if (local_err != NULL) {
         error_propagate(errp, local_err);