rewrite most of the saga

nexus/db-queries/src/db/datastore/instance.rs

@@ -478,7 +478,6 @@ impl DataStore {
         opctx: &OpContext,
         authz_instance: &authz::Instance,
         saga_lock_id: &Uuid,
-        updater_gen: Generation,
     ) -> Result<bool, Error> {
         use db::schema::instance::dsl;
 
@@ -491,8 +490,6 @@ impl DataStore {
             // - the provided updater ID matches that of the saga that has
             //   currently locked this instance.
             .filter(dsl::updater_id.eq(Some(*saga_lock_id)))
-            // - the generation is the same as the captured generation.
-            .filter(dsl::updater_gen.eq(updater_gen))
             .set((
                 dsl::updater_gen.eq(dsl::updater_gen + 1),
                 dsl::updater_id.eq(None::<Uuid>),

nexus/src/app/background/instance_updater.rs

@@ -59,16 +59,7 @@ impl InstanceUpdater {
         stats.destroyed_active_vmms = destroyed_active_vmms.len();
 
         for InstanceAndActiveVmm { instance, vmm } in destroyed_active_vmms {
-            let saga = SagaRequest::InstanceUpdate {
-                params: sagas::instance_update::Params {
-                    serialized_authn: authn::saga::Serialized::for_opctx(opctx),
-                    state: InstanceAndVmms {
-                        instance,
-                        active_vmm: vmm,
-                        target_vmm: None,
-                    },
-                },
-            };
+            let saga = SagaRequest::InstanceUpdate { params: todo!() };
             self.saga_req
                 .send(saga)
                 .await

nexus/src/app/instance.rs

@@ -1338,12 +1338,7 @@ impl super::Nexus {
         if let Some(state) = state {
             let update_result = self
                 .db_datastore
-                .instance_and_vmm_update_runtime(
-                    instance_id,
-                    &state.instance_state.into(),
-                    &state.propolis_id,
-                    &state.vmm_state.into(),
-                )
+                .vmm_update_runtime(&state.propolis_id, &state.vmm_state.into())
                 .await;
 
             slog::debug!(&self.log,
@@ -1352,7 +1347,8 @@ impl super::Nexus {
                          "propolis_id" => %state.propolis_id,
                          "result" => ?update_result);
 
-            update_result
+            // TODO(eliza): probably just change the retval to `bool` later...
+            update_result.map(|vmm_updated| (false, vmm_updated))
         } else {
             Ok((false, false))
         }
@@ -2002,7 +1998,11 @@ pub(crate) async fn notify_instance_updated(
         .await?;
 
     let updated = datastore
-        .vmm_update_runtime(&propolis_id, &new_runtime_state.vmm_state)
+        .vmm_update_runtime(
+            &propolis_id,
+            // TODO(eliza): probably should take this by value...
+            &new_runtime_state.vmm_state.clone().into(),
+        )
         .await?;
 
     // // Update OPTE and Dendrite if the instance's active sled assignment

nexus/src/app/mod.rs

@@ -931,7 +931,7 @@ impl Nexus {
                     &self.log,
                     o!(
                         "saga" => "instance_update",
-                        "instance_id" => params.state.instance.id().to_string(),
+                        "instance_id" => params.authz_instance.id().to_string(),
                     ),
                 );
                 tokio::spawn(async move {

nexus/src/app/sagas/instance_update/destroyed.rs

@@ -5,31 +5,21 @@
 use super::ActionRegistry;
 use super::NexusActionContext;
 use super::NexusSaga;
+use super::Params;
+use super::STATE;
 use crate::app::sagas::declare_saga_actions;
 use crate::app::sagas::ActionError;
-use db::lookup::LookupPath;
 use nexus_db_model::Generation;
+use nexus_db_model::Instance;
 use nexus_db_model::InstanceRuntimeState;
+use nexus_db_model::Vmm;
+use nexus_db_queries::db::datastore::InstanceAndVmms;
 use nexus_db_queries::db::identity::Resource;
-use nexus_db_queries::{authn, authz, db};
 use omicron_common::api::external;
 use omicron_common::api::external::Error;
-use omicron_common::api::external::ResourceType;
-use serde::{Deserialize, Serialize};
+use omicron_common::api::external::InstanceState;
 use slog::info;
 
-/// Parameters to the instance update VMM destroyed sub-saga.
-#[derive(Debug, Deserialize, Serialize)]
-pub(crate) struct Params {
-    /// Authentication context to use to fetch the instance's current state from
-    /// the database.
-    pub serialized_authn: authn::saga::Serialized,
-
-    pub instance: db::model::Instance,
-
-    pub vmm: db::model::Vmm,
-}
-
 // instance update VMM destroyed subsaga: actions
 
 // This subsaga is responsible for handling an instance update where the
@@ -102,20 +92,38 @@ impl NexusSaga for SagaVmmDestroyed {
     }
 }
 
+fn get_destroyed_vmm(
+    sagactx: &NexusActionContext,
+) -> Result<Option<(Instance, Vmm)>, ActionError> {
+    let state = sagactx.lookup::<InstanceAndVmms>(STATE)?;
+    match state.active_vmm {
+        Some(vmm) if vmm.runtime.state.state() == &InstanceState::Destroyed => {
+            Ok(Some((state.instance, vmm)))
+        }
+        _ => Ok(None),
+    }
+}
+
 async fn siud_release_sled_resources(
     sagactx: NexusActionContext,
 ) -> Result<(), ActionError> {
+    let Some((_, vmm)) = get_destroyed_vmm(&sagactx)? else {
+        // if the update we are handling is not an active VMM destroyed update,
+        // bail --- there's nothing to do here.
+        return Ok(());
+    };
+
     let osagactx = sagactx.user_data();
-    let Params { ref serialized_authn, ref vmm, ref instance, .. } =
+    let Params { ref serialized_authn, ref authz_instance } =
         sagactx.saga_params::<Params>()?;
 
     let opctx =
         crate::context::op_context_for_saga_action(&sagactx, serialized_authn);
 
     info!(
         osagactx.log(),
-        "instance update (VMM destroyed): deallocating sled resource reservation";
-        "instance_id" => %instance.id(),
+        "instance update (active VMM destroyed): deallocating sled resource reservation";
+        "instance_id" => %authz_instance.id(),
         "propolis_id" => %vmm.id,
         "instance_update" => %"VMM destroyed",
     );
@@ -137,8 +145,14 @@ async fn siud_release_sled_resources(
 async fn siud_release_virtual_provisioning(
     sagactx: NexusActionContext,
 ) -> Result<(), ActionError> {
+    let Some((instance, vmm)) = get_destroyed_vmm(&sagactx)? else {
+        // if the update we are handling is not an active VMM destroyed update,
+        // bail --- there's nothing to do here.
+        return Ok(());
+    };
+
     let osagactx = sagactx.user_data();
-    let Params { ref serialized_authn, ref instance, ref vmm, .. } =
+    let Params { ref serialized_authn, ref authz_instance } =
         sagactx.saga_params::<Params>()?;
 
     let opctx =
@@ -147,7 +161,7 @@ async fn siud_release_virtual_provisioning(
     info!(
         osagactx.log(),
         "instance update (VMM destroyed): deallocating virtual provisioning resources";
-        "instance_id" => %instance.id(),
+        "instance_id" => %authz_instance.id(),
         "propolis_id" => %vmm.id,
         "instance_update" => %"VMM destroyed",
     );
@@ -156,7 +170,7 @@ async fn siud_release_virtual_provisioning(
         .datastore()
         .virtual_provisioning_collection_delete_instance(
             &opctx,
-            instance.id(),
+            authz_instance.id(),
             instance.project_id,
             i64::from(instance.ncpus.0 .0),
             instance.memory,
@@ -176,8 +190,13 @@ async fn siud_release_virtual_provisioning(
 async fn siud_unassign_oximeter_producer(
     sagactx: NexusActionContext,
 ) -> Result<(), ActionError> {
+    let Some((_, vmm)) = get_destroyed_vmm(&sagactx)? else {
+        // if the update we are handling is not an active VMM destroyed update,
+        // bail --- there's nothing to do here.
+        return Ok(());
+    };
     let osagactx = sagactx.user_data();
-    let Params { ref instance, ref serialized_authn, .. } =
+    let Params { ref serialized_authn, ref authz_instance, .. } =
         sagactx.saga_params::<Params>()?;
 
     let opctx =
@@ -187,7 +206,7 @@ async fn siud_unassign_oximeter_producer(
         osagactx.datastore(),
         osagactx.log(),
         &opctx,
-        &instance.id(),
+        &authz_instance.id(),
     )
     .await
     .map_err(ActionError::action_failed)
@@ -196,10 +215,12 @@ async fn siud_unassign_oximeter_producer(
 async fn siud_delete_v2p_mappings(
     sagactx: NexusActionContext,
 ) -> Result<(), ActionError> {
+    let Some((instance, vmm)) = get_destroyed_vmm(&sagactx)? else {
+        // if the update we are handling is not an active VMM destroyed update,
+        // bail --- there's nothing to do here.
+        return Ok(());
+    };
     let osagactx = sagactx.user_data();
-    let Params { ref instance, ref vmm, .. } =
-        sagactx.saga_params::<Params>()?;
-
     info!(
         osagactx.log(),
         "instance update (VMM destroyed): deleting V2P mappings";
@@ -216,8 +237,13 @@ async fn siud_delete_v2p_mappings(
 async fn siud_delete_nat_entries(
     sagactx: NexusActionContext,
 ) -> Result<(), ActionError> {
+    let Some((_, vmm)) = get_destroyed_vmm(&sagactx)? else {
+        // if the update we are handling is not an active VMM destroyed update,
+        // bail --- there's nothing to do here.
+        return Ok(());
+    };
     let osagactx = sagactx.user_data();
-    let Params { ref serialized_authn, ref vmm, ref instance, .. } =
+    let Params { ref serialized_authn, ref authz_instance, .. } =
         sagactx.saga_params::<Params>()?;
 
     let opctx =
@@ -226,16 +252,11 @@ async fn siud_delete_nat_entries(
     info!(
         osagactx.log(),
         "instance update (VMM destroyed): deleting NAT entries";
-        "instance_id" => %instance.id(),
+        "instance_id" => %authz_instance.id(),
         "propolis_id" => %vmm.id,
         "instance_update" => %"VMM destroyed",
     );
 
-    let (.., authz_instance) = LookupPath::new(&opctx, &osagactx.datastore())
-        .instance_id(instance.id())
-        .lookup_for(authz::Action::Modify)
-        .await
-        .map_err(ActionError::action_failed)?;
     osagactx
         .nexus()
         .instance_delete_dpd_config(&opctx, &authz_instance)
@@ -247,8 +268,12 @@ async fn siud_delete_nat_entries(
 async fn siud_update_instance(
     sagactx: NexusActionContext,
 ) -> Result<(), ActionError> {
+    let Some((instance, vmm)) = get_destroyed_vmm(&sagactx)? else {
+        // if the update we are handling is not an active VMM destroyed update,
+        // bail --- there's nothing to do here.
+        return Ok(());
+    };
     let osagactx = sagactx.user_data();
-    let Params { instance, vmm, .. } = sagactx.saga_params::<Params>()?;
     let new_runtime = InstanceRuntimeState {
         propolis_id: None,
         nexus_state: external::InstanceState::Stopped.into(),
@@ -276,8 +301,13 @@ async fn siud_update_instance(
 async fn siud_mark_vmm_deleted(
     sagactx: NexusActionContext,
 ) -> Result<(), ActionError> {
+    let Some((instance, vmm)) = get_destroyed_vmm(&sagactx)? else {
+        // if the update we are handling is not an active VMM destroyed update,
+        // bail --- there's nothing to do here.
+        return Ok(());
+    };
     let osagactx = sagactx.user_data();
-    let Params { ref serialized_authn, ref vmm, ref instance, .. } =
+    let Params { ref serialized_authn, .. } =
         sagactx.saga_params::<Params>()?;
 
     let opctx =