Today if we detect concurrent modification of a snapshot repository then we mark it with `CORRUPTED_REPO_GEN` which blocks further writes to try and prevent additional damage to its contents. You can remove the marker by calling the register-repository API again, but this API will discard no-op re-registrations without taking any action. You can work around this by unregistering the repository first (which may be impossible if it's still in use for searchable snapshots) or by re-registering it with some trivial setting change (which seems hacky).

We should not consider it a no-op re-registration if the repository is currently marked with `CORRUPTED_REPO_GEN`, because doing this re-registration will re-read the repo contents and clear the corruption marker and therefore is not a no-op.
test/framework/src/main/java/org/elasticsearch/snapshots/AbstractSnapshotIntegTestCase.java
&& state.custom(SnapshotDeletionsInProgress.TYPE, SnapshotDeletionsInProgress.EMPTY).hasDeletionsInProgress() == false
        );
    }
    protected void awaitClusterState(Predicate<ClusterState> statePredicate) throws Exception {
        awaitClusterState(logger, internalCluster().getMasterName(), statePredicate);
    }
    public static void awaitClusterState(Logger logger, Predicate<ClusterState> statePredicate) throws Exception {
        awaitClusterState(logger, internalCluster().getMasterName(), statePredicate);
    }
    public static void awaitClusterState(Logger logger, String viaNode, Predicate<ClusterState> statePredicate) throws Exception {
        ClusterServiceUtils.awaitClusterState(logger, statePredicate, internalCluster().getInstance(ClusterService.class, viaNode));
    }
    protected ActionFuture<CreateSnapshotResponse> startFullSnapshotBlockedOnDataNode(String snapshotName, String repoName, String dataNode)
        throws Exception {
        blockDataNode(repoName, dataNode);
        final ActionFuture<CreateSnapshotResponse> fut = startFullSnapshot(repoName, snapshotName);
        waitForBlock(dataNode, repoName);
        return fut;
    }
    protected ActionFuture<CreateSnapshotResponse> startFullSnapshot(String repoName, String snapshotName) {
        return startFullSnapshot(repoName, snapshotName, false);
    }
    protected ActionFuture<CreateSnapshotResponse> startFullSnapshot(String repoName, String snapshotName, boolean partial) {
        return startFullSnapshot(logger, repoName, snapshotName, partial);
    }
    public static ActionFuture<CreateSnapshotResponse> startFullSnapshot(
        Logger logger,
        String repoName,
        String snapshotName,
        boolean partial