removes id from push_lowest_slot args (#18645)

push_lowest_slot cannot sign the new crds-value unless the id (pubkey)
argument passed-in is the same pubkey as in ClusterInfo::keypair(), in
which case the id argument is redundant:
https://github.com/solana-labs/solana/blob/bb41cf346/gossip/src/cluster_info.rs#L824-L845

Additionally, the lookup is done with self.id(), but insert is done with
the id argument, which is logically a bug.

core/src/cluster_slots_service.rs

@@ -4,7 +4,7 @@ use solana_gossip::cluster_info::ClusterInfo;
 use solana_ledger::blockstore::Blockstore;
 use solana_measure::measure::Measure;
 use solana_runtime::bank_forks::BankForks;
-use solana_sdk::{clock::Slot, pubkey::Pubkey};
+use solana_sdk::clock::Slot;
 use std::{
     sync::{
         atomic::{AtomicBool, Ordering},
@@ -43,8 +43,7 @@ impl ClusterSlotsService {
         cluster_slots_update_receiver: ClusterSlotsUpdateReceiver,
         exit: Arc<AtomicBool>,
     ) -> Self {
-        let id = cluster_info.id();
-        Self::initialize_lowest_slot(id, &blockstore, &cluster_info);
+        Self::initialize_lowest_slot(&blockstore, &cluster_info);
         Self::initialize_epoch_slots(&bank_forks, &cluster_info);
         let t_cluster_slots_service = Builder::new()
             .name("solana-cluster-slots-service".to_string())
@@ -93,10 +92,9 @@ impl ClusterSlotsService {
                 }
             };
             let new_root = bank_forks.read().unwrap().root();
-            let id = cluster_info.id();
             let mut lowest_slot_elapsed = Measure::start("lowest_slot_elapsed");
             let lowest_slot = blockstore.lowest_slot();
-            Self::update_lowest_slot(&id, lowest_slot, &cluster_info);
+            Self::update_lowest_slot(lowest_slot, &cluster_info);
             lowest_slot_elapsed.stop();
             let mut process_cluster_slots_updates_elapsed =
                 Measure::start("process_cluster_slots_updates_elapsed");
@@ -151,16 +149,16 @@ impl ClusterSlotsService {
         }
     }
 
-    fn initialize_lowest_slot(id: Pubkey, blockstore: &Blockstore, cluster_info: &ClusterInfo) {
+    fn initialize_lowest_slot(blockstore: &Blockstore, cluster_info: &ClusterInfo) {
         // Safe to set into gossip because by this time, the leader schedule cache should
         // also be updated with the latest root (done in blockstore_processor) and thus
         // will provide a schedule to window_service for any incoming shreds up to the
         // last_confirmed_epoch.
-        cluster_info.push_lowest_slot(id, blockstore.lowest_slot());
+        cluster_info.push_lowest_slot(blockstore.lowest_slot());
     }
 
-    fn update_lowest_slot(id: &Pubkey, lowest_slot: Slot, cluster_info: &ClusterInfo) {
-        cluster_info.push_lowest_slot(*id, lowest_slot);
+    fn update_lowest_slot(lowest_slot: Slot, cluster_info: &ClusterInfo) {
+        cluster_info.push_lowest_slot(lowest_slot);
     }
 
     fn initialize_epoch_slots(bank_forks: &RwLock<BankForks>, cluster_info: &ClusterInfo) {
@@ -179,15 +177,18 @@ impl ClusterSlotsService {
 
 #[cfg(test)]
 mod test {
-    use super::*;
-    use solana_gossip::{cluster_info::Node, crds_value::CrdsValueLabel};
+    use {
+        super::*,
+        solana_gossip::{cluster_info::Node, crds_value::CrdsValueLabel},
+        solana_sdk::pubkey::Pubkey,
+    };
 
     #[test]
     pub fn test_update_lowest_slot() {
         let pubkey = Pubkey::new_unique();
         let node_info = Node::new_localhost_with_pubkey(&pubkey);
         let cluster_info = ClusterInfo::new_with_invalid_keypair(node_info.info);
-        ClusterSlotsService::update_lowest_slot(&pubkey, 5, &cluster_info);
+        ClusterSlotsService::update_lowest_slot(5, &cluster_info);
         cluster_info.flush_push_queue();
         let lowest = {
             let label = CrdsValueLabel::LowestSlot(pubkey);

gossip/src/cluster_info.rs

@@ -821,20 +821,20 @@ impl ClusterInfo {
         )
     }
 
-    pub fn push_lowest_slot(&self, id: Pubkey, min: Slot) {
-        let now = timestamp();
-        let last = self
-            .gossip
-            .read()
-            .unwrap()
-            .crds
-            .get(&CrdsValueLabel::LowestSlot(self.id()))
-            .and_then(|x| x.value.lowest_slot())
-            .map(|x| x.lowest)
-            .unwrap_or(0);
+    pub fn push_lowest_slot(&self, min: Slot) {
+        let self_pubkey = self.id();
+        let last = {
+            let gossip = self.gossip.read().unwrap();
+            gossip
+                .crds
+                .get_lowest_slot(self_pubkey)
+                .map(|x| x.lowest)
+                .unwrap_or_default()
+        };
         if min > last {
+            let now = timestamp();
             let entry = CrdsValue::new_signed(
-                CrdsData::LowestSlot(0, LowestSlot::new(id, min, now)),
+                CrdsData::LowestSlot(0, LowestSlot::new(self_pubkey, min, now)),
                 &self.keypair(),
             );
             self.local_message_pending_push_queue

gossip/src/crds_value.rs

@@ -83,7 +83,7 @@ impl Signable for CrdsValue {
 pub enum CrdsData {
     ContactInfo(ContactInfo),
     Vote(VoteIndex, Vote),
-    LowestSlot(u8, LowestSlot),
+    LowestSlot(/*DEPRECATED:*/ u8, LowestSlot),
     SnapshotHashes(SnapshotHash),
     AccountsHashes(SnapshotHash),
     EpochSlots(EpochSlotsIndex, EpochSlots),