Merge pull request #95 from smoser/feature/add-thinpool

Add support for CreateLV with thin or thinpool.

.github/workflows/build.yml

@@ -18,6 +18,11 @@ jobs:
       run: |
         go mod download
 
+    - name: Install Deps
+      run: |
+        sudo apt-get update --quiet
+        sudo apt-get install --quiet --assume-yes --no-install-recommends lvm2 thin-provisioning-tools
+
     - name: build
       run: |
         make build

linux/lvm.go

@@ -9,6 +9,9 @@ import (
 	"github.com/anuvu/disko"
 )
 
+const pvMetaDataSize = 128 * disko.Mebibyte
+const thinPoolMetaDataSize = 1024 * disko.Mebibyte
+
 // VolumeManager returns the linux implementation of disko.VolumeManager interface.
 func VolumeManager() disko.VolumeManager {
 	return &linuxLVM{}
@@ -168,7 +171,8 @@ func (ls *linuxLVM) CreatePV(name string) (disko.PV, error) {
 		return nilPV, err
 	}
 
-	err = runCommandSettled("lvm", "pvcreate", "--zero=y", path)
+	err = runCommandSettled("lvm", "pvcreate", "--zero=y",
+		fmt.Sprintf("--metadatasize=%dB", pvMetaDataSize), path)
 
 	if err != nil {
 		return nilPV, err
@@ -201,9 +205,8 @@ func (ls *linuxLVM) HasPV(name string) bool {
 }
 
 func (ls *linuxLVM) CreateVG(name string, pvs ...disko.PV) (disko.VG, error) {
-	const mdSize = 128 * disko.Mebibyte
 	cmd := []string{"lvm", "vgcreate",
-		fmt.Sprintf("--metadatasize=%dB", mdSize),
+		fmt.Sprintf("--metadatasize=%dB", pvMetaDataSize),
 		"--zero=y", name}
 
 	for _, p := range pvs {
@@ -269,6 +272,25 @@ func (ls *linuxLVM) CryptClose(vgName string, lvName string,
 	return runCommand("cryptsetup", "close", decryptedName)
 }
 
+func createLVCmd(args ...string) error {
+	return runCommandSettled(
+		append([]string{"lvm", "lvcreate", "--ignoremonitoring", "--yes", "--activate=y",
+			"--setactivationskip=n"}, args...)...)
+}
+
+func createThinPool(name string, vgName string, size uint64, mdSize uint64) error {
+	// thinpool takes up size + 2*mdSize
+	// https://www.redhat.com/archives/linux-lvm/2020-October/thread.html#00016
+	args := []string{}
+	// if mdSize is zero, let lvcreate choose the size. That is documented as:
+	//  (Pool_LV_size / Pool_LV_chunk_size * 64)
+	if mdSize != 0 {
+		args = append(args, fmt.Sprintf("--poolmetadatasize=%dB", mdSize))
+	}
+
+	return createLVCmd(append(args, fmt.Sprintf("--size=%dB", size), "--thinpool="+name, vgName)...)
+}
+
 func (ls *linuxLVM) CreateLV(vgName string, name string, size uint64,
 	lvType disko.LVType) (disko.LV, error) {
 	nilLV := disko.LV{}
@@ -277,22 +299,35 @@ func (ls *linuxLVM) CreateLV(vgName string, name string, size uint64,
 		return nilLV, err
 	}
 
-	if lvType == disko.THIN {
-		// thin lv creation would require creating a pool
-		return nilLV, fmt.Errorf("not supported. Thin LV create not implemented")
-	}
+	nameFlag := "--name=" + name
+	sizeB := fmt.Sprintf("%dB", size)
+	vglv := vgLv(vgName, name)
 
-	err := runCommandSettled(
-		"lvm", "lvcreate", "--ignoremonitoring", "--yes", "--activate=y",
-		"--zero=y",
-		"--setactivationskip=n", fmt.Sprintf("--size=%dB", size),
-		fmt.Sprintf("--name=%s", name), vgName)
+	switch lvType {
+	case disko.THIN:
+		// When creating THIN LV, the VG must be <vgname>/<thinLVName>
+		if !strings.Contains(vgName, "/") {
+			return nilLV,
+				fmt.Errorf("%s: vgName input for THIN LV name in format <vgname>/thinDataName", vgName)
+		}
 
-	if err != nil {
-		return nilLV, err
+		vglv = vgLv(strings.Split(vgName, "/")[0], name)
+
+		if err := createLVCmd("--virtualsize="+sizeB, nameFlag, vgName); err != nil {
+			return nilLV, err
+		}
+	case disko.THICK:
+		if err := createLVCmd("--size="+sizeB, nameFlag, vgName); err != nil {
+			return nilLV, err
+		}
+	case disko.THINPOOL:
+		// When creating a THINPOOL, the name is the thin pool name.
+		if err := createThinPool(name, vgName, size, thinPoolMetaDataSize); err != nil {
+			return nilLV, err
+		}
 	}
 
-	lvs, err := ls.scanLVs(func(d disko.LV) bool { return true }, vgLv(vgName, name))
+	lvs, err := ls.scanLVs(func(d disko.LV) bool { return true }, vglv)
 
 	if err != nil {
 		return nilLV, err

linux/root_test.go

@@ -234,3 +234,98 @@ func TestRootLVMExtend(t *testing.T) {
 	foundLv = vgs[vgname].Volumes[lvname]
 	ast.Equalf(size2, foundLv.Size, "extended volume size incorrect")
 }
+
+func runShow(args ...string) {
+	out, err, rc := runCommandWithOutputErrorRc(args...)
+	fmt.Print(cmdString(args, out, err, rc))
+}
+
+func TestRootLVMCreate(t *testing.T) {
+	iSkipOrFail(t, isRoot, canUseLoop, canUseLVM)
+
+	ast := assert.New(t)
+
+	var cl = cleanList{}
+	defer cl.Cleanup(t)
+
+	var pv disko.PV
+	var vg disko.VG
+	var lv disko.LV
+	var c cleaner
+	var tmpFile string
+
+	lvthick := "diskot-thick" + randStr(8)
+	lvthinpool := "diskot-pool" + randStr(8)
+	lvthin := "diskot-thin" + randStr(8)
+	vgname := "diskot-vg" + randStr(8)
+
+	c, tmpFile = getTempFile(4 * GiB)
+	cl.Add(c)
+
+	lCleanup, disk, err := singlePartDisk(tmpFile)
+	cl.AddF(lCleanup, "singlePartdisk")
+
+	if err != nil {
+		t.Fatalf("Failed to create a single part disk: %s", err)
+	}
+
+	lvm := linux.VolumeManager()
+
+	pv, err = lvm.CreatePV(disk.Path + "p1")
+	if err != nil {
+		t.Fatalf("Failed to create pv on %s: %s\n", disk.Path, err)
+	}
+
+	cl.AddF(func() error { return lvm.DeletePV(pv) }, "remove pv")
+
+	vg, err = lvm.CreateVG(vgname, pv)
+
+	if err != nil {
+		t.Fatalf("Failed to create %s with %s: %s", vgname, pv.Path, err)
+	}
+
+	cl.AddF(func() error { return lvm.RemoveVG(vgname) }, "remove VG")
+
+	ast.Equal(vgname, vg.Name)
+
+	thickSize := uint64(12 * MiB)
+
+	lv, err = lvm.CreateLV(vgname, lvthick, thickSize, disko.THICK)
+	if err != nil {
+		t.Fatalf("Failed to create lv %s/%s: %s", vgname, lvthick, err)
+	}
+
+	cl.AddF(func() error { return lvm.RemoveLV(vgname, lvthick) }, "remove LV")
+
+	ast.Equal(lvthick, lv.Name)
+	ast.Equal(thickSize, lv.Size)
+
+	thinPoolSize, thinSize := uint64(500*MiB), uint64(200*MiB)
+
+	// create a THINPOOL volume
+	lv, err = lvm.CreateLV(vgname, lvthinpool, thinPoolSize, disko.THINPOOL)
+	if err != nil {
+		t.Fatalf("Failed to create lv %s/%s: %s", vgname, lvthick, err)
+	}
+
+	cl.AddF(func() error { return lvm.RemoveLV(vgname, lvthinpool) }, "remove thin pool LV")
+
+	ast.Equal(lvthinpool, lv.Name)
+	ast.Equal(thinPoolSize, lv.Size)
+
+	lv, err = lvm.CreateLV(vgname+"/"+lvthinpool, lvthin, thinSize, disko.THIN)
+	if err != nil {
+		runShow("lvm", "lvdisplay", "--unit=m", vgname)
+		t.Fatalf("Failed to create THIN lv %s on %s/%s: %s", lvthin, vgname, lvthinpool, err)
+	}
+
+	ast.Equal(lvthin, lv.Name)
+	ast.Equal(thinSize, lv.Size)
+
+	vgs, errScan := lvm.ScanVGs(func(v disko.VG) bool { return v.Name == vgname })
+	if errScan != nil {
+		t.Fatalf("Failed to scan VGs: %s\n", err)
+	}
+
+	ast.Equal(len(vgs), 1)
+}