non-empty dirs should not be listed as objects (#9129)

cmd/fs-v1.go

@@ -1058,15 +1058,18 @@ func (fs *FSObjects) DeleteObject(ctx context.Context, bucket, object string) er
 // is a leaf or non-leaf entry.
 func (fs *FSObjects) listDirFactory() ListDirFunc {
 	// listDir - lists all the entries at a given prefix and given entry in the prefix.
-	listDir := func(bucket, prefixDir, prefixEntry string) (entries []string) {
+	listDir := func(bucket, prefixDir, prefixEntry string) (emptyDir bool, entries []string) {
 		var err error
 		entries, err = readDir(pathJoin(fs.fsPath, bucket, prefixDir))
 		if err != nil && err != errFileNotFound {
 			logger.LogIf(context.Background(), err)
-			return
+			return false, nil
+		}
+		if len(entries) == 0 {
+			return true, nil
 		}
 		sort.Strings(entries)
-		return filterMatchingPrefix(entries, prefixEntry)
+		return false, filterMatchingPrefix(entries, prefixEntry)
 	}
 
 	// Return list factory instance.

cmd/gateway/hdfs/gateway-hdfs.go

@@ -326,7 +326,7 @@ func (n *hdfsObjects) ListBuckets(ctx context.Context) (buckets []minio.BucketIn
 
 func (n *hdfsObjects) listDirFactory() minio.ListDirFunc {
 	// listDir - lists all the entries at a given prefix and given entry in the prefix.
-	listDir := func(bucket, prefixDir, prefixEntry string) (entries []string) {
+	listDir := func(bucket, prefixDir, prefixEntry string) (emptyDir bool, entries []string) {
 		f, err := n.clnt.Open(minio.PathJoin(hdfsSeparator, bucket, prefixDir))
 		if err != nil {
 			if os.IsNotExist(err) {
@@ -341,6 +341,9 @@ func (n *hdfsObjects) listDirFactory() minio.ListDirFunc {
 			logger.LogIf(context.Background(), err)
 			return
 		}
+		if len(fis) == 0 {
+			return true, nil
+		}
 		for _, fi := range fis {
 			if fi.IsDir() {
 				entries = append(entries, fi.Name()+hdfsSeparator)
@@ -348,7 +351,7 @@ func (n *hdfsObjects) listDirFactory() minio.ListDirFunc {
 				entries = append(entries, fi.Name())
 			}
 		}
-		return minio.FilterMatchingPrefix(entries, prefixEntry)
+		return false, minio.FilterMatchingPrefix(entries, prefixEntry)
 	}
 
 	// Return list factory instance.

cmd/object-api-listobjects_test.go

@@ -45,6 +45,8 @@ func testListObjects(obj ObjectLayer, instanceType string, t1 TestErrHandler) {
 		// Will not store any objects in this bucket,
 		// Its to test ListObjects on an empty bucket.
 		"empty-bucket",
+		// Listing the case where the marker > last object.
+		"test-bucket-single-object",
 	}
 	for _, bucket := range testBuckets {
 		err := obj.MakeBucketWithLocation(context.Background(), bucket, "")
@@ -72,6 +74,7 @@ func testListObjects(obj ObjectLayer, instanceType string, t1 TestErrHandler) {
 		{testBuckets[1], "obj1", "obj1", nil},
 		{testBuckets[1], "obj2", "obj2", nil},
 		{testBuckets[1], "temporary/0/", "", nil},
+		{testBuckets[3], "A/B", "contentstring", nil},
 	}
 	for _, object := range testObjects {
 		md5Bytes := md5.Sum([]byte(object.content))
@@ -445,6 +448,11 @@ func testListObjects(obj ObjectLayer, instanceType string, t1 TestErrHandler) {
 				{Name: "temporary/0/"},
 			},
 		},
+		// ListObjectsResult-34 Listing with marker > last object should return empty
+		{
+			IsTruncated: false,
+			Objects:     []ObjectInfo{},
+		},
 	}
 
 	testCases := []struct {
@@ -559,6 +567,8 @@ func testListObjects(obj ObjectLayer, instanceType string, t1 TestErrHandler) {
 		{"test-bucket-empty-dir", "", "", SlashSeparator, 10, resultCases[32], nil, true},
 		// Test listing a directory which contains an empty directory (64)
 		{"test-bucket-empty-dir", "", "temporary/", "", 10, resultCases[33], nil, true},
+		// Test listing with marker > last object such that response should be empty (65)
+		{"test-bucket-single-object", "", "A/C", "", 1000, resultCases[34], nil, true},
 	}
 
 	for i, testCase := range testCases {

cmd/posix.go

@@ -669,13 +669,16 @@ func (s *posix) Walk(volume, dirPath, marker string, recursive bool, leafFile st
 	ch = make(chan FileInfo)
 	go func() {
 		defer close(ch)
-		listDir := func(volume, dirPath, dirEntry string) (entries []string) {
+		listDir := func(volume, dirPath, dirEntry string) (emptyDir bool, entries []string) {
 			entries, err := s.ListDir(volume, dirPath, -1, leafFile)
 			if err != nil {
 				return
 			}
+			if len(entries) == 0 {
+				return true, nil
+			}
 			sort.Strings(entries)
-			return filterMatchingPrefix(entries, dirEntry)
+			return false, filterMatchingPrefix(entries, dirEntry)
 		}
 
 		walkResultCh := startTreeWalk(context.Background(), volume, dirPath, marker, recursive, listDir, endWalkCh)

cmd/tree-walk.go

@@ -56,10 +56,10 @@ func filterMatchingPrefix(entries []string, prefixEntry string) []string {
 }
 
 // ListDirFunc - "listDir" function of type listDirFunc returned by listDirFactory() - explained below.
-type ListDirFunc func(bucket, prefixDir, prefixEntry string) (entries []string)
+type ListDirFunc func(bucket, prefixDir, prefixEntry string) (emptyDir bool, entries []string)
 
 // treeWalk walks directory tree recursively pushing TreeWalkResult into the channel as and when it encounters files.
-func doTreeWalk(ctx context.Context, bucket, prefixDir, entryPrefixMatch, marker string, recursive bool, listDir ListDirFunc, resultCh chan TreeWalkResult, endWalkCh <-chan struct{}, isEnd bool) (totalNum int, treeErr error) {
+func doTreeWalk(ctx context.Context, bucket, prefixDir, entryPrefixMatch, marker string, recursive bool, listDir ListDirFunc, resultCh chan TreeWalkResult, endWalkCh <-chan struct{}, isEnd bool) (emptyDir bool, treeErr error) {
 	// Example:
 	// if prefixDir="one/two/three/" and marker="four/five.txt" treeWalk is recursively
 	// called with prefixDir="one/two/three/four/" and marker="five.txt"
@@ -75,10 +75,10 @@ func doTreeWalk(ctx context.Context, bucket, prefixDir, entryPrefixMatch, marker
 		}
 	}
 
-	entries := listDir(bucket, prefixDir, entryPrefixMatch)
+	emptyDir, entries := listDir(bucket, prefixDir, entryPrefixMatch)
 	// For an empty list return right here.
-	if len(entries) == 0 {
-		return 0, nil
+	if emptyDir {
+		return true, nil
 	}
 
 	// example:
@@ -90,7 +90,7 @@ func doTreeWalk(ctx context.Context, bucket, prefixDir, entryPrefixMatch, marker
 	entries = entries[idx:]
 	// For an empty list after search through the entries, return right here.
 	if len(entries) == 0 {
-		return 0, nil
+		return false, nil
 	}
 
 	for i, entry := range entries {
@@ -123,16 +123,16 @@ func doTreeWalk(ctx context.Context, bucket, prefixDir, entryPrefixMatch, marker
 			// markIsEnd is passed to this entry's treeWalk() so that treeWalker.end can be marked
 			// true at the end of the treeWalk stream.
 			markIsEnd := i == len(entries)-1 && isEnd
-			totalFound, err := doTreeWalk(ctx, bucket, pentry, prefixMatch, markerArg, recursive,
+			emptyDir, err := doTreeWalk(ctx, bucket, pentry, prefixMatch, markerArg, recursive,
 				listDir, resultCh, endWalkCh, markIsEnd)
 			if err != nil {
-				return 0, err
+				return false, err
 			}
 
 			// A nil totalFound means this is an empty directory that
 			// needs to be sent to the result channel, otherwise continue
 			// to the next entry.
-			if totalFound > 0 {
+			if !emptyDir {
 				continue
 			}
 		}
@@ -141,13 +141,13 @@ func doTreeWalk(ctx context.Context, bucket, prefixDir, entryPrefixMatch, marker
 		isEOF := ((i == len(entries)-1) && isEnd)
 		select {
 		case <-endWalkCh:
-			return 0, errWalkAbort
+			return false, errWalkAbort
 		case resultCh <- TreeWalkResult{entry: pentry, end: isEOF}:
 		}
 	}
 
 	// Everything is listed.
-	return len(entries), nil
+	return false, nil
 }
 
 // Initiate a new treeWalk in a goroutine.

cmd/tree-walk_test.go

@@ -260,7 +260,7 @@ func TestListDir(t *testing.T) {
 	}
 
 	// Should list "file1" from fsDir1.
-	entries := listDir(volume, "", "")
+	_, entries := listDir(volume, "", "")
 	if len(entries) != 2 {
 		t.Fatal("Expected the number of entries to be 2")
 	}
@@ -278,7 +278,7 @@ func TestListDir(t *testing.T) {
 	}
 
 	// Should list "file2" from fsDir2.
-	entries = listDir(volume, "", "")
+	_, entries = listDir(volume, "", "")
 	if len(entries) != 1 {
 		t.Fatal("Expected the number of entries to be 1")
 	}

cmd/xl-v1-list-objects.go

@@ -25,7 +25,7 @@ import (
 // disks - used for doing disk.ListDir()
 func listDirFactory(ctx context.Context, disks ...StorageAPI) ListDirFunc {
 	// Returns sorted merged entries from all the disks.
-	listDir := func(bucket, prefixDir, prefixEntry string) (mergedEntries []string) {
+	listDir := func(bucket, prefixDir, prefixEntry string) (emptyDir bool, mergedEntries []string) {
 		for _, disk := range disks {
 			if disk == nil {
 				continue
@@ -38,6 +38,10 @@ func listDirFactory(ctx context.Context, disks ...StorageAPI) ListDirFunc {
 				continue
 			}
 
+			if len(entries) == 0 {
+				return true, nil
+			}
+
 			// Find elements in entries which are not in mergedEntries
 			for _, entry := range entries {
 				idx := sort.SearchStrings(mergedEntries, entry)
@@ -54,7 +58,7 @@ func listDirFactory(ctx context.Context, disks ...StorageAPI) ListDirFunc {
 				sort.Strings(mergedEntries)
 			}
 		}
-		return filterMatchingPrefix(mergedEntries, prefixEntry)
+		return false, filterMatchingPrefix(mergedEntries, prefixEntry)
 	}
 	return listDir
 }