Block multiple sled reservations with the same gen

dev-tools/omdb/src/bin/omdb/db.rs

@@ -7865,25 +7865,24 @@ async fn cmd_db_vmm_info(
         include_sled_id: bool,
     ) {
         use db::model::ByteCount;
-        let db::model::SledResourceVmm {
-            id: _,
-            sled_id,
-            resources:
-                db::model::Resources {
-                    hardware_threads,
-                    rss_ram: ByteCount(rss),
-                    reservoir_ram: ByteCount(reservoir),
-                },
-            instance_id: _,
-        } = resource;
+
+        let sled_id = &resource.sled_id;
+        let db::model::Resources {
+            hardware_threads,
+            rss_ram: ByteCount(rss),
+            reservoir_ram: ByteCount(reservoir),
+        } = &resource.resources;
+
         const SLED_ID: &'static str = "sled ID";
         const THREADS: &'static str = "hardware threads";
         const RSS: &'static str = "RSS RAM";
         const RESERVOIR: &'static str = "reservoir RAM";
         const WIDTH: usize = const_max_len(&[SLED_ID, THREADS, RSS, RESERVOIR]);
+
         if include_sled_id {
             println!("    {SLED_ID:>WIDTH$}: {sled_id}");
         }
+
         println!("    {THREADS:>WIDTH$}: {hardware_threads}");
         println!("    {RSS:>WIDTH$}: {rss}");
         println!("    {RESERVOIR:>WIDTH$}: {reservoir}");

nexus/db-model/src/schema_versions.rs

@@ -16,7 +16,7 @@ use std::{collections::BTreeMap, sync::LazyLock};
 ///
 /// This must be updated when you change the database schema.  Refer to
 /// schema/crdb/README.adoc in the root of this repository for details.
-pub const SCHEMA_VERSION: Version = Version::new(261, 0, 0);
+pub const SCHEMA_VERSION: Version = Version::new(262, 0, 0);
 
 /// List of all past database schema versions, in *reverse* order
 ///
@@ -28,6 +28,7 @@ pub static KNOWN_VERSIONS: LazyLock<Vec<KnownVersion>> = LazyLock::new(|| {
         // |  leaving the first copy as an example for the next person.
         // v
         // KnownVersion::new(next_int, "unique-dirname-with-the-sql-files"),
+        KnownVersion::new(262, "sled-resource-vmm-instance-state-generation"),
         KnownVersion::new(261, "remove-add-zones-with-mupdate-override"),
         KnownVersion::new(260, "ereport-trim-serial-trailing-nulls"),
         KnownVersion::new(259, "vmm-failure-reason"),

nexus/db-model/src/sled_resource_vmm.rs

@@ -2,6 +2,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
+use crate::Generation;
 use crate::typed_uuid::DbTypedUuid;
 use crate::{ByteCount, SqlU32};
 use nexus_db_schema::schema::sled_resource_vmm;
@@ -34,6 +35,14 @@ impl Resources {
     }
 }
 
+#[derive(Clone, Debug)]
+pub enum SledResourceVmmInstanceStateGeneration {
+    /// Row was created prior to Nexus recording this
+    Unspecified,
+
+    Specified(Generation),
+}
+
 /// Describes sled resource usage by a VMM
 #[derive(Clone, Selectable, Queryable, Insertable, Debug)]
 #[diesel(table_name = sled_resource_vmm)]
@@ -45,6 +54,9 @@ pub struct SledResourceVmm {
     pub resources: Resources,
 
     pub instance_id: Option<DbInstanceUuid>,
+
+    /// The instance's state_generation at the moment of reservation
+    instance_state_generation: Option<Generation>,
 }
 
 impl SledResourceVmm {
@@ -53,12 +65,14 @@ impl SledResourceVmm {
         instance_id: InstanceUuid,
         sled_id: SledUuid,
         resources: Resources,
+        instance_state_generation: Generation,
     ) -> Self {
         Self {
             id: id.into(),
             instance_id: Some(instance_id.into()),
             sled_id: sled_id.into(),
             resources,
+            instance_state_generation: Some(instance_state_generation),
         }
     }
 
@@ -73,4 +87,16 @@ impl SledResourceVmm {
     pub fn instance_id(&self) -> Option<InstanceUuid> {
         self.instance_id.map(|x| x.into())
     }
+
+    pub fn instance_state_generation(
+        &self,
+    ) -> SledResourceVmmInstanceStateGeneration {
+        match &self.instance_state_generation {
+            Some(generation) => {
+                SledResourceVmmInstanceStateGeneration::Specified(*generation)
+            }
+
+            None => SledResourceVmmInstanceStateGeneration::Unspecified,
+        }
+    }
 }

nexus/db-queries/benches/harness/db_utils.rs

@@ -73,6 +73,7 @@ pub async fn create_reservation(
             .sled_reservation_create(
                 &opctx,
                 instance_id,
+                nexus_db_model::Generation::new(),
                 vmm_id,
                 small_resource_request(),
                 SledReservationConstraintBuilder::new().build(),

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

@@ -1314,6 +1314,7 @@ mod tests {
                     ByteCount::from_kibibytes_u32(1).into(),
                     ByteCount::from_kibibytes_u32(1).into(),
                 ),
+                nexus_db_model::Generation::new(),
             ))
             .execute_async(
                 &*datastore.pool_connection_for_tests().await.unwrap(),