From e211f6f52e0203cf3353df4fcaea6f5e7c1ef2e5 Mon Sep 17 00:00:00 2001
From: Praveen raj Mani <praveen@minio.io>
Date: Fri, 23 Aug 2019 08:32:40 +0530
Subject: [PATCH] Parallelize the DiskInfo calls in xl.StorageInfo() (#8115)

---
 cmd/xl-sets.go | 26 +++++++++++++++++++-------
 cmd/xl-v1.go   | 31 +++++++++++++++++++------------
 2 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/cmd/xl-sets.go b/cmd/xl-sets.go
index 32f04d93f..8fb04d05d 100644
--- a/cmd/xl-sets.go
+++ b/cmd/xl-sets.go
@@ -304,14 +304,26 @@ func newXLSets(endpoints EndpointList, format *formatXLV3, setCount int, drivesP
 // StorageInfo - combines output of StorageInfo across all erasure coded object sets.
 func (s *xlSets) StorageInfo(ctx context.Context) StorageInfo {
 	var storageInfo StorageInfo
+	var wg sync.WaitGroup
+
+	storageInfos := make([]StorageInfo, len(s.sets))
 	storageInfo.Backend.Type = BackendErasure
-	for _, set := range s.sets {
-		lstorageInfo := set.StorageInfo(ctx)
-		storageInfo.Used = storageInfo.Used + lstorageInfo.Used
-		storageInfo.Total = storageInfo.Total + lstorageInfo.Total
-		storageInfo.Available = storageInfo.Available + lstorageInfo.Available
-		storageInfo.Backend.OnlineDisks = storageInfo.Backend.OnlineDisks + lstorageInfo.Backend.OnlineDisks
-		storageInfo.Backend.OfflineDisks = storageInfo.Backend.OfflineDisks + lstorageInfo.Backend.OfflineDisks
+	for index, set := range s.sets {
+		wg.Add(1)
+		go func(id int, set *xlObjects) {
+			defer wg.Done()
+			storageInfos[id] = set.StorageInfo(ctx)
+		}(index, set)
+	}
+	// Wait for the go routines.
+	wg.Wait()
+
+	for _, lstorageInfo := range storageInfos {
+		storageInfo.Used += lstorageInfo.Used
+		storageInfo.Total += lstorageInfo.Total
+		storageInfo.Available += lstorageInfo.Available
+		storageInfo.Backend.OnlineDisks += lstorageInfo.Backend.OnlineDisks
+		storageInfo.Backend.OfflineDisks += lstorageInfo.Backend.OfflineDisks
 	}
 
 	scData, scParity := getRedundancyCount(standardStorageClass, s.drivesPerSet)
diff --git a/cmd/xl-v1.go b/cmd/xl-v1.go
index 712936a1b..42fb376e1 100644
--- a/cmd/xl-v1.go
+++ b/cmd/xl-v1.go
@@ -19,6 +19,7 @@ package cmd
 import (
 	"context"
 	"sort"
+	"sync"
 
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/bpool"
@@ -70,26 +71,32 @@ func (d byDiskTotal) Less(i, j int) bool {
 // getDisksInfo - fetch disks info across all other storage API.
 func getDisksInfo(disks []StorageAPI) (disksInfo []DiskInfo, onlineDisks int, offlineDisks int) {
 	disksInfo = make([]DiskInfo, len(disks))
+	var wg sync.WaitGroup
 	for i, storageDisk := range disks {
 		if storageDisk == nil {
 			// Storage disk is empty, perhaps ignored disk or not available.
 			offlineDisks++
 			continue
 		}
-		info, err := storageDisk.DiskInfo()
-		if err != nil {
-			ctx := context.Background()
-			logger.GetReqInfo(ctx).AppendTags("disk", storageDisk.String())
-			logger.LogIf(ctx, err)
-			if IsErr(err, baseErrs...) {
-				offlineDisks++
-				continue
+		wg.Add(1)
+		go func(id int, sDisk StorageAPI) {
+			defer wg.Done()
+			info, err := sDisk.DiskInfo()
+			if err != nil {
+				reqInfo := (&logger.ReqInfo{}).AppendTags("disk", sDisk.String())
+				ctx := logger.SetReqInfo(context.Background(), reqInfo)
+				logger.LogIf(ctx, err)
+				if IsErr(err, baseErrs...) {
+					offlineDisks++
+					return
+				}
 			}
-		}
-		onlineDisks++
-		disksInfo[i] = info
+			onlineDisks++
+			disksInfo[id] = info
+		}(i, storageDisk)
 	}
-
+	// Wait for the routines.
+	wg.Wait()
 	// Success.
 	return disksInfo, onlineDisks, offlineDisks
 }