fs: fix XFS and other FS related issue due to missing d_type.

Makefile

@@ -131,9 +131,11 @@ install: gomake-all
 dockerimage: checkdocker getdeps verifiers $(UI_ASSETS)
 	@echo "Building docker image:" minio:$(TAG)
 	@GO15VENDOREXPERIMENT=1 GOOS=linux GOARCH=amd64 go build --ldflags $(DOCKER_LDFLAGS) -o docker/minio.dockerimage
+	@touch docker/dockerinit
 	@cd docker; mkdir -p export; sudo docker build --rm --tag=minio/minio:$(TAG) .
 	@rmdir docker/export
 	@rm docker/minio.dockerimage
+	@rm docker/dockerinit
 
 release: verifiers
 	@MINIO_RELEASE=RELEASE ./buildscripts/build.sh

docker/Dockerfile

@@ -2,6 +2,7 @@
 FROM alpine:3.3
 RUN apk add --no-cache ca-certificates bash
 ADD minio.dockerimage /minio
+ADD dockerinit /.dockerinit
 ADD export /export
 EXPOSE 9000
 COPY start.sh /start.sh

fs-dir-nix.go

@@ -48,7 +48,7 @@ func clen(n []byte) int {
 
 // parseDirents - inspired from
 // https://golang.org/src/syscall/syscall_<os>.go
-func parseDirents(buf []byte) []fsDirent {
+func parseDirents(dirPath string, buf []byte) []fsDirent {
 	bufidx := 0
 	dirents := []fsDirent{}
 	for bufidx < len(buf) {
@@ -87,7 +87,16 @@ func parseDirents(buf []byte) []fsDirent {
 		case syscall.DT_SOCK:
 			mode = os.ModeSocket
 		case syscall.DT_UNKNOWN:
-			mode = 0xffffffff
+			// On Linux XFS and few other file systems do not implement d_type in dirents.
+			// Fall back to Stat() in these scenarios.
+			if fi, err := os.Stat(filepath.Join(dirPath, name)); err == nil {
+				mode = fi.Mode()
+			} else {
+				// Stat failed, caller listing files would fail. But we will not crash
+				// the server.
+				mode = 0xffffffff
+			}
+
 		}
 
 		dirents = append(dirents, fsDirent{
@@ -115,7 +124,7 @@ func readDirAll(readDirPath, entryPrefixMatch string) ([]fsDirent, error) {
 		if nbuf <= 0 {
 			break
 		}
-		for _, dirent := range parseDirents(buf[:nbuf]) {
+		for _, dirent := range parseDirents(readDirPath, buf[:nbuf]) {
 			if dirent.IsDir() {
 				dirent.name += string(os.PathSeparator)
 				dirent.size = 0
@@ -151,7 +160,7 @@ func scandir(dirPath string, filter func(fsDirent) bool, namesOnly bool) ([]fsDi
 		if nbuf <= 0 {
 			break
 		}
-		for _, dirent := range parseDirents(buf[:nbuf]) {
+		for _, dirent := range parseDirents(dirPath, buf[:nbuf]) {
 			if !namesOnly {
 				dirent.name = filepath.Join(dirPath, dirent.name)
 			}

server-main.go

@@ -148,7 +148,7 @@ func initServerConfig(c *cli.Context) {
 
 // Check server arguments.
 func checkServerSyntax(c *cli.Context) {
-	if c.Args().First() == "help" {
+	if !c.Args().Present() || c.Args().First() == "help" {
 		cli.ShowCommandHelpAndExit(c, "server", 1)
 	}
 	if len(c.Args()) > 2 {