From d0d015361c2994358c7d88209dc99b40e57d2e94 Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Wed, 5 Sep 2018 08:25:55 -0700
Subject: [PATCH] Fix config subsystem to wait on quorum number of formatted
 disks (#6407)

---
 cmd/server-main.go |  6 +++---
 cmd/xl-sets.go     | 32 ++++++++++++++++++++++++++++++--
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/cmd/server-main.go b/cmd/server-main.go
index 74f43753b..cf41f3d42 100644
--- a/cmd/server-main.go
+++ b/cmd/server-main.go
@@ -318,6 +318,9 @@ func serverMain(ctx *cli.Context) {
 		initFederatorBackend(newObject)
 	}
 
+	// Re-enable logging
+	logger.Disable = false
+
 	// Create a new config system.
 	globalConfigSys = NewConfigSys()
 
@@ -336,9 +339,6 @@ func serverMain(ctx *cli.Context) {
 		logger.FatalIf(err, "Unable to initialize disk caching")
 	}
 
-	// Re-enable logging
-	logger.Disable = false
-
 	// Create new policy system.
 	globalPolicySys = NewPolicySys()
 
diff --git a/cmd/xl-sets.go b/cmd/xl-sets.go
index ee65adfff..2f0808c34 100644
--- a/cmd/xl-sets.go
+++ b/cmd/xl-sets.go
@@ -168,6 +168,34 @@ func (s *xlSets) reInitDisks(refFormat *formatXLV3, storageDisks []StorageAPI, f
 	return xlDisks
 }
 
+// connectDisksWithQuorum is same as connectDisks but waits
+// for quorum number of formatted disks to be online in
+// any given sets.
+func (s *xlSets) connectDisksWithQuorum() {
+	var onlineDisks int
+	for onlineDisks < (len(s.endpoints)/2)+1 {
+		for _, endpoint := range s.endpoints {
+			if s.isConnected(endpoint) {
+				continue
+			}
+			disk, format, err := connectEndpoint(endpoint)
+			if err != nil {
+				printEndpointError(endpoint, err)
+				continue
+			}
+			i, j, err := findDiskIndex(s.format, format)
+			if err != nil {
+				// Close the internal connection to avoid connection leaks.
+				disk.Close()
+				printEndpointError(endpoint, err)
+				continue
+			}
+			s.xlDisks[i][j] = disk
+			onlineDisks++
+		}
+	}
+}
+
 // connectDisks - attempt to connect all the endpoints, loads format
 // and re-arranges the disks in proper position.
 func (s *xlSets) connectDisks() {
@@ -260,8 +288,8 @@ func newXLSets(endpoints EndpointList, format *formatXLV3, setCount int, drivesP
 		go s.sets[i].cleanupStaleMultipartUploads(context.Background(), globalMultipartCleanupInterval, globalMultipartExpiry, globalServiceDoneCh)
 	}
 
-	// Connect disks right away.
-	s.connectDisks()
+	// Connect disks right away, but wait until we have `format.json` quorum.
+	s.connectDisksWithQuorum()
 
 	// Start the disk monitoring and connect routine.
 	go s.monitorAndConnectEndpoints(defaultMonitorConnectEndpointInterval)