Added support for setting the OS X volume name.

While I was at it, added tests for fsname. I can't figure out how to
test the volume name.

For GoogleCloudPlatform/gcsfuse#125.

mount_config.go

@@ -129,6 +129,12 @@ type MountConfig struct {
 	// entries will be cached for an arbitrarily long time.
 	EnableVnodeCaching bool
 
+	// OS X only.
+	//
+	// The name of the mounted volume, as displayed in the Finder. If empty, a
+	// default name involving the string 'osxfuse' is used.
+	VolumeName string
+
 	// Additional key=value options to pass unadulterated to the underlying mount
 	// command. See `man 8 mount`, the fuse documentation, etc. for
 	// system-specific information.
@@ -172,11 +178,18 @@ func (c *MountConfig) toMap() (opts map[string]string) {
 		opts["ro"] = ""
 	}
 
-	// OS X: set novncache when appropriate.
-	if isDarwin && !c.EnableVnodeCaching {
+	// Handle OS X options.
+	if isDarwin {
+		if !c.EnableVnodeCaching {
 			opts["novncache"] = ""
 		}
 
+		if c.VolumeName != "" {
+			// Cf. https://github.com/osxfuse/osxfuse/wiki/Mount-options#volname
+			opts["volname"] = c.VolumeName
+		}
+	}
+
 	// OS X: disable the use of "Apple Double" (._foo and .DS_Store) files, which
 	// just add noise to debug output and can have significant cost on
 	// network-based file systems.

samples/statfs/statfs_darwin_test.go

@@ -20,7 +20,6 @@ import (
 	"syscall"
 
 	"github.com/jacobsa/fuse/fuseops"
-	. "github.com/jacobsa/oglematchers"
 	. "github.com/jacobsa/ogletest"
 )
 
@@ -72,9 +71,7 @@ func (t *StatFSTest) Syscall_ZeroValues() {
 	ExpectEq(0, stat.Ffree)
 	ExpectEq("osxfusefs", convertName(stat.Fstypename[:]))
 	ExpectEq(t.canonicalDir, convertName(stat.Mntonname[:]))
-	ExpectThat(
-		convertName(stat.Mntfromname[:]),
-		MatchesRegexp(`mount_osxfusefs@osxfuse\d+`))
+	ExpectEq(fsName, convertName(stat.Mntfromname[:]))
 }
 
 func (t *StatFSTest) Syscall_NonZeroValues() {
@@ -108,9 +105,7 @@ func (t *StatFSTest) Syscall_NonZeroValues() {
 	ExpectEq(canned.InodesFree, stat.Ffree)
 	ExpectEq("osxfusefs", convertName(stat.Fstypename[:]))
 	ExpectEq(t.canonicalDir, convertName(stat.Mntonname[:]))
-	ExpectThat(
-		convertName(stat.Mntfromname[:]),
-		MatchesRegexp(`mount_osxfusefs@osxfuse\d+`))
+	ExpectEq(fsName, convertName(stat.Mntfromname[:]))
 }
 
 func (t *StatFSTest) UnsupportedBlockSizes() {

samples/statfs/statfs_test.go

@@ -34,6 +34,9 @@ import (
 
 func TestStatFS(t *testing.T) { RunTests(t) }
 
+const fsName = "some_fs_name"
+const volumeName = "Some volume"
+
 ////////////////////////////////////////////////////////////////////////
 // Helpers
 ////////////////////////////////////////////////////////////////////////
@@ -117,6 +120,10 @@ func (t *StatFSTest) SetUp(ti *TestInfo) {
 	// being issued from the client.
 	t.MountConfig.DisableWritebackCaching = true
 
+	// Configure names.
+	t.MountConfig.FSName = fsName
+	t.MountConfig.VolumeName = volumeName
+
 	// Create the file system.
 	t.fs = statfs.New()
 	t.Server = fuseutil.NewFileSystemServer(t.fs)