From 0fe9e9525086d7e01604c00a5511a5af61d5645e Mon Sep 17 00:00:00 2001
From: Harshavardhana <harsha@minio.io>
Date: Thu, 16 Aug 2018 16:49:38 -0700
Subject: [PATCH] Validate prefixes on all sets (#6294)

This PR fixes a regression introduced in 8eb838bf91bf7d98aa2ba9eac976e78c9530225e
where hashing technique was used on prefixes to get the right set
to perform the operation, this is not correct since prefixes and
their corresponding keys might hash to a different value depending
on the key length.

For prefixes/directories we should look everywhere to support proper
quorum based listing.

Fixes #6293
---
 cmd/xl-sets.go | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/cmd/xl-sets.go b/cmd/xl-sets.go
index 93220f421..68dde9ec6 100644
--- a/cmd/xl-sets.go
+++ b/cmd/xl-sets.go
@@ -714,7 +714,15 @@ func (s *xlSets) ListObjects(ctx context.Context, bucket, prefix, marker, delimi
 		}
 
 		isLeafDir := func(bucket, entry string) bool {
-			return s.getHashedSet(entry).isObjectDir(bucket, entry)
+			// Verify prefixes in all sets.
+			var ok bool
+			for _, set := range s.sets {
+				ok = set.isObjectDir(bucket, entry)
+				if ok {
+					return true
+				}
+			}
+			return false
 		}
 
 		var setDisks = make([][]StorageAPI, len(s.sets))
@@ -742,7 +750,13 @@ func (s *xlSets) ListObjects(ctx context.Context, bucket, prefix, marker, delimi
 		var objInfo ObjectInfo
 		var err error
 		if hasSuffix(walkResult.entry, slashSeparator) {
-			objInfo, err = s.getHashedSet(walkResult.entry).getObjectInfoDir(ctx, bucket, walkResult.entry)
+			// Verify prefixes in all sets.
+			for _, set := range s.sets {
+				objInfo, err = set.getObjectInfoDir(ctx, bucket, walkResult.entry)
+				if err == nil {
+					break
+				}
+			}
 		} else {
 			objInfo, err = s.getHashedSet(walkResult.entry).getObjectInfo(ctx, bucket, walkResult.entry)
 		}
@@ -1349,7 +1363,14 @@ func (s *xlSets) listObjectsHeal(ctx context.Context, bucket, prefix, marker, de
 		}
 
 		isLeafDir := func(bucket, entry string) bool {
-			return s.getHashedSet(entry).isObjectDir(bucket, entry)
+			var ok bool
+			for _, set := range s.sets {
+				ok = set.isObjectDir(bucket, entry)
+				if ok {
+					return true
+				}
+			}
+			return false
 		}
 
 		var setDisks = make([][]StorageAPI, len(s.sets))