Add WithLoopDevices to report loop devices

pkg/block/block.go

@@ -29,6 +29,7 @@ const (
 	DRIVE_TYPE_FDD               // Floppy disk drive
 	DRIVE_TYPE_ODD               // Optical disk drive
 	DRIVE_TYPE_SSD               // Solid-state drive
+	DRIVE_TYPE_VIRTUAL           // virtual drive i.e. loop devices
 )
 
 var (
@@ -38,6 +39,7 @@ var (
 		DRIVE_TYPE_FDD:     "FDD",
 		DRIVE_TYPE_ODD:     "ODD",
 		DRIVE_TYPE_SSD:     "SSD",
+		DRIVE_TYPE_VIRTUAL: "virtual",
 	}
 
 	// NOTE(fromani): the keys are all lowercase and do not match
@@ -51,6 +53,7 @@ var (
 		"fdd":     DRIVE_TYPE_FDD,
 		"odd":     DRIVE_TYPE_ODD,
 		"ssd":     DRIVE_TYPE_SSD,
+		"virtual": DRIVE_TYPE_VIRTUAL,
 	}
 )
 
@@ -93,6 +96,7 @@ const (
 	STORAGE_CONTROLLER_NVME                      // Non-volatile Memory Express
 	STORAGE_CONTROLLER_VIRTIO                    // Virtualized storage controller/driver
 	STORAGE_CONTROLLER_MMC                       // Multi-media controller (used for mobile phone storage devices)
+	STORAGE_CONTROLLER_LOOP                      // loop device
 )
 
 var (
@@ -103,6 +107,7 @@ var (
 		STORAGE_CONTROLLER_NVME:    "NVMe",
 		STORAGE_CONTROLLER_VIRTIO:  "virtio",
 		STORAGE_CONTROLLER_MMC:     "MMC",
+		STORAGE_CONTROLLER_LOOP:    "loop",
 	}
 
 	// NOTE(fromani): the keys are all lowercase and do not match
@@ -117,6 +122,7 @@ var (
 		"nvme":    STORAGE_CONTROLLER_NVME,
 		"virtio":  STORAGE_CONTROLLER_VIRTIO,
 		"mmc":     STORAGE_CONTROLLER_MMC,
+		"loop":    STORAGE_CONTROLLER_LOOP,
 	}
 )
 

pkg/block/block_linux.go

@@ -309,9 +309,6 @@ func disks(ctx *context.Context, paths *linuxpath.Paths) []*Disk {
 	}
 	for _, file := range files {
 		dname := file.Name()
-		if strings.HasPrefix(dname, "loop") {
-			continue
-		}
 
 		driveType, storageController := diskTypes(dname)
 		// TODO(jaypipes): Move this into diskTypes() once abstracting
@@ -329,6 +326,10 @@ func disks(ctx *context.Context, paths *linuxpath.Paths) []*Disk {
 		wwn := diskWWN(paths, dname)
 		removable := diskIsRemovable(paths, dname)
 
+		if storageController == STORAGE_CONTROLLER_LOOP && size == 0 {
+			// We don't care about unused loop devices...
+			continue
+		}
 		d := &Disk{
 			Name:                   dname,
 			SizeBytes:              size,
@@ -390,6 +391,9 @@ func diskTypes(dname string) (
 	} else if strings.HasPrefix(dname, "mmc") {
 		driveType = DRIVE_TYPE_SSD
 		storageController = STORAGE_CONTROLLER_MMC
+	} else if strings.HasPrefix(dname, "loop") {
+		driveType = DRIVE_TYPE_VIRTUAL
+		storageController = STORAGE_CONTROLLER_LOOP
 	}
 
 	return driveType, storageController

pkg/block/block_linux_test.go

@@ -19,6 +19,7 @@ import (
 
 	"github.com/jaypipes/ghw/pkg/context"
 	"github.com/jaypipes/ghw/pkg/linuxpath"
+	"github.com/jaypipes/ghw/pkg/option"
 	"github.com/jaypipes/ghw/pkg/util"
 )
 
@@ -168,6 +169,13 @@ func TestDiskTypes(t *testing.T) {
 				storageController: STORAGE_CONTROLLER_UNKNOWN,
 			},
 		},
+		{
+			line: "loop0",
+			expected: entry{
+				driveType:         DRIVE_TYPE_VIRTUAL,
+				storageController: STORAGE_CONTROLLER_LOOP,
+			},
+		},
 	}
 
 	for _, test := range tests {
@@ -248,3 +256,53 @@ func TestDiskTypeUdev(t *testing.T) {
 		t.Fatalf("Got partition type %s, but expected %s", pt, util.UNKNOWN)
 	}
 }
+
+// TestLoopDevicesWithOption tests to see if we find loop devices when the option is activated
+func TestLoopDevicesWithOption(t *testing.T) {
+	if _, ok := os.LookupEnv("GHW_TESTING_SKIP_BLOCK"); ok {
+		t.Skip("Skipping block tests.")
+	}
+	baseDir, _ := ioutil.TempDir("", "test")
+	defer os.RemoveAll(baseDir)
+	ctx := context.New(option.WithNullAlerter(), option.WithDisableTools())
+	ctx.Chroot = baseDir
+	paths := linuxpath.New(ctx)
+	fsType := "ext4"
+	expectedLoopName := "loop0"
+	loopNotUsed := "loop1"
+	loopPartitionName := "loop0p1"
+
+	_ = os.MkdirAll(paths.SysBlock, 0755)
+	_ = os.MkdirAll(paths.RunUdevData, 0755)
+
+	// Emulate a loop device with one partition and another loop deviced not used
+	_ = os.Mkdir(filepath.Join(paths.SysBlock, expectedLoopName), 0755)
+	_ = os.Mkdir(filepath.Join(paths.SysBlock, loopNotUsed), 0755)
+	_ = os.Mkdir(filepath.Join(paths.SysBlock, expectedLoopName, "queue"), 0755)
+	_ = os.Mkdir(filepath.Join(paths.SysBlock, loopNotUsed, "queue"), 0755)
+	_ = ioutil.WriteFile(filepath.Join(paths.SysBlock, expectedLoopName, "queue", "rotational"), []byte("1\n"), 0644)
+	_ = ioutil.WriteFile(filepath.Join(paths.SysBlock, expectedLoopName, "size"), []byte("62810112\n"), 0644)
+	_ = ioutil.WriteFile(filepath.Join(paths.SysBlock, loopNotUsed, "size"), []byte("0\n"), 0644)
+	_ = os.Mkdir(filepath.Join(paths.SysBlock, expectedLoopName, loopPartitionName), 0755)
+	_ = ioutil.WriteFile(filepath.Join(paths.SysBlock, expectedLoopName, loopPartitionName, "dev"), []byte("259:0\n"), 0644)
+	_ = ioutil.WriteFile(filepath.Join(paths.SysBlock, expectedLoopName, loopPartitionName, "size"), []byte("102400\n"), 0644)
+	_ = ioutil.WriteFile(filepath.Join(paths.RunUdevData, "b259:0"), []byte(fmt.Sprintf("E:ID_FS_TYPE=%s\n", fsType)), 0644)
+	d := disks(ctx, paths)
+	// There should be one disk, the other should be ignored due to 0 size
+	if len(d) != 1 {
+		t.Fatalf("expected one disk device but the function reported %d", len(d))
+	}
+	foundDisk := d[0]
+	// Should be the one we faked
+	if foundDisk.Name != expectedLoopName {
+		t.Fatalf("got loop device %s but expected %s", foundDisk.Name, expectedLoopName)
+	}
+	// Should have only one partition
+	if len(foundDisk.Partitions) != 1 {
+		t.Fatalf("expected one partition but the function reported %d", len(foundDisk.Partitions))
+	}
+	// Name should match
+	if foundDisk.Partitions[0].Name != loopPartitionName {
+		t.Fatalf("got partition %s but expected %s", foundDisk.Partitions[0], loopPartitionName)
+	}
+}

pkg/block/block_test.go

@@ -41,7 +41,15 @@ func TestBlock(t *testing.T) {
 		t.Fatalf("Expected >0 disks. Got %d", len(disks))
 	}
 
-	d0 := disks[0]
+	var d0 *block.Disk
+	// Skip loop devices on generic tests as we don't know what the underlying system is going to have
+	// And loop devices don't have Serial Numbers for example.
+	for _, d := range disks {
+		if d.StorageController != block.STORAGE_CONTROLLER_LOOP {
+			d0 = d
+			break
+		}
+	}
 	if d0.Name == "" {
 		t.Fatalf("Expected disk name, but got \"\"")
 	}