erasure: Call Walk() from all disks (#10445)

It does not make sense to call Walk() in only N/2 disks and then
requires N/2 quorum, just keep it N/2+1 

The commit fixes this behavior.

cmd/erasure-common.go

@@ -34,7 +34,9 @@ func (er erasureObjects) getLoadBalancedLocalDisks() (newDisks []StorageAPI) {
 	return newDisks
 }
 
-// getLoadBalancedNDisks - fetches load balanced (sufficiently randomized) disk slice with N disks online
+// getLoadBalancedNDisks - fetches load balanced (sufficiently randomized) disk slice
+// with N disks online. If ndisks is zero or negative, then it will returns all disks,
+// same if ndisks is greater than the number of all disks.
 func (er erasureObjects) getLoadBalancedNDisks(ndisks int) (newDisks []StorageAPI) {
 	disks := er.getLoadBalancedDisks()
 	for _, disk := range disks {

cmd/erasure-zones.go

@@ -911,7 +911,7 @@ func (z *erasureZones) listObjects(ctx context.Context, bucket, prefix, marker,
 		entryChs, endWalkCh := zone.pool.Release(listParams{bucket, recursive, marker, prefix})
 		if entryChs == nil {
 			endWalkCh = make(chan struct{})
-			entryChs = zone.startMergeWalksN(ctx, bucket, prefix, marker, recursive, endWalkCh, zone.listTolerancePerSet, false)
+			entryChs = zone.startMergeWalksN(ctx, bucket, prefix, marker, recursive, endWalkCh, zone.listTolerancePerSet+1, false)
 		}
 		zonesEntryChs = append(zonesEntryChs, entryChs)
 		zonesEndWalkCh = append(zonesEndWalkCh, endWalkCh)
@@ -1280,7 +1280,7 @@ func (z *erasureZones) listObjectVersions(ctx context.Context, bucket, prefix, m
 		entryChs, endWalkCh := zone.poolVersions.Release(listParams{bucket, recursive, marker, prefix})
 		if entryChs == nil {
 			endWalkCh = make(chan struct{})
-			entryChs = zone.startMergeWalksVersionsN(ctx, bucket, prefix, marker, recursive, endWalkCh, zone.listTolerancePerSet)
+			entryChs = zone.startMergeWalksVersionsN(ctx, bucket, prefix, marker, recursive, endWalkCh, zone.listTolerancePerSet+1)
 		}
 		zonesEntryChs = append(zonesEntryChs, entryChs)
 		zonesEndWalkCh = append(zonesEndWalkCh, endWalkCh)