From 5b8fe2e89a64ee9244faa2b34cdee6b40597fcb5 Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Fri, 23 Dec 2022 20:55:45 -0800
Subject: [PATCH] allow locks with object affinity to spread across pools
 (#16312)

---
 cmd/erasure-server-pool.go | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/cmd/erasure-server-pool.go b/cmd/erasure-server-pool.go
index 2df31dfff..ffad41ee4 100644
--- a/cmd/erasure-server-pool.go
+++ b/cmd/erasure-server-pool.go
@@ -32,6 +32,7 @@ import (
 	"time"
 
 	"github.com/dustin/go-humanize"
+	"github.com/google/uuid"
 	"github.com/minio/madmin-go/v2"
 	"github.com/minio/minio-go/v7/pkg/s3utils"
 	"github.com/minio/minio-go/v7/pkg/set"
@@ -50,6 +51,9 @@ type erasureServerPools struct {
 	rebalMu   sync.RWMutex
 	rebalMeta *rebalanceMeta
 
+	deploymentID     [16]byte
+	distributionAlgo string
+
 	serverPools []*erasureSets
 
 	// Shut down async operations
@@ -124,6 +128,14 @@ func newErasureServerPools(ctx context.Context, endpointServerPools EndpointServ
 		if err != nil {
 			return nil, err
 		}
+
+		if deploymentID != "" && bytes.Equal(z.deploymentID[:], []byte{}) {
+			z.deploymentID = uuid.MustParse(deploymentID)
+		}
+
+		if distributionAlgo != "" && z.distributionAlgo == "" {
+			z.distributionAlgo = distributionAlgo
+		}
 	}
 
 	z.decommissionCancelers = make([]context.CancelFunc, len(z.serverPools))
@@ -154,7 +166,11 @@ func newErasureServerPools(ctx context.Context, endpointServerPools EndpointServ
 }
 
 func (z *erasureServerPools) NewNSLock(bucket string, objects ...string) RWLocker {
-	return z.serverPools[0].NewNSLock(bucket, objects...)
+	poolID := hashKey(z.distributionAlgo, "", len(z.serverPools), z.deploymentID)
+	if len(objects) >= 1 {
+		poolID = hashKey(z.distributionAlgo, objects[0], len(z.serverPools), z.deploymentID)
+	}
+	return z.serverPools[poolID].NewNSLock(bucket, objects...)
 }
 
 // GetDisksID will return disks by their ID.