save device type instead of caching it (#2023)

* save device type instead of caching it

* add func comments

* split checking device type in a separate funtion

* storing device type after cache or detection, return types without storing if it's vm

* add to broken devices if type is not detected

* improve readability

* improve readability

* use the correct pool mounting path

* update doc string

---------

Co-authored-by: Muhamad Azamy <muhamad@incubaid.com>

pkg/cache/cache.go

@@ -13,7 +13,7 @@ const (
 
 // VolatileDir creates a new cache directory that is stored on a tmpfs.
 // This means data stored in this directory will NOT survive a reboot.
-// Use this when you need to store data that needs to survice deamon reboot but not between reboots
+// Use this when you need to store data that needs to survive deamon reboot but not between reboots
 // It is the caller's responsibility to remove the directory when no longer needed.
 // If the directory already exist error of type os.IsExist will be returned
 func VolatileDir(name string, size uint64) (string, error) {

pkg/storage/filesystem/btrfs.go

@@ -11,6 +11,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog/log"
+	"github.com/threefoldtech/zos/pkg/gridtypes/zos"
 )
 
 var (
@@ -308,6 +309,45 @@ func (p *btrfsPool) Shutdown() error {
 	return nil
 }
 
+// SetType sets the device type to the disk
+func (p *btrfsPool) SetType(typ zos.DeviceType) error {
+	path, err := p.Mounted()
+	if err != nil {
+		return err
+	}
+	diskTypePath := filepath.Join(path, ".seektime")
+	if err := os.WriteFile(diskTypePath, []byte(typ), 0644); err != nil {
+		return errors.Wrapf(err, "failed to store device type for '%s' in '%s'", p.Name(), diskTypePath)
+	}
+
+	return nil
+}
+
+// Type gets the device type from the disk
+// return the device type, if it's found and an error
+// that's based on .seektime file existing in the /mnt/DeviceName/.seektime, that contains the device type being SSD or HDD
+func (p *btrfsPool) Type() (zos.DeviceType, bool, error) {
+	path, err := p.Mounted()
+	if err != nil {
+		return "", false, err
+	}
+	diskTypePath := filepath.Join(path, ".seektime")
+	diskType, err := os.ReadFile(diskTypePath)
+	if os.IsNotExist(err) {
+		return "", false, nil
+	}
+
+	if err != nil {
+		return "", false, err
+	}
+
+	if len(diskType) == 0 {
+		return "", false, nil
+	}
+
+	return zos.DeviceType(diskType), true, nil
+}
+
 type btrfsVolume struct {
 	id    int
 	path  string

pkg/storage/filesystem/device.go

@@ -68,7 +68,8 @@ func (i *DeviceInfo) Used() bool {
 	return len(i.Label) != 0 || len(i.Filesystem) != 0
 }
 
-func (d *DeviceInfo) Type() (zos.DeviceType, error) {
+// DetectType returns the device type according to seektime
+func (d *DeviceInfo) DetectType() (zos.DeviceType, error) {
 	return d.mgr.Seektime(context.Background(), d.Path)
 }
 

pkg/storage/filesystem/device_test.go

@@ -76,7 +76,7 @@ func TestDeviceManagerScan(t *testing.T) {
 	// make sure all types are set.
 	expected := []zos.DeviceType{zos.SSDDevice, zos.HDDDevice}
 	for i, dev := range cached {
-		typ, err := dev.Type()
+		typ, err := dev.DetectType()
 		require.NoError(err)
 		require.Equal(expected[i], typ)
 	}

pkg/storage/filesystem/filesystem.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/pkg/errors"
+	"github.com/threefoldtech/zos/pkg/gridtypes/zos"
 )
 
 // Usage struct (in bytes)
@@ -72,6 +73,13 @@ type Pool interface {
 	Shutdown() error
 	// Device return device associated with pool
 	Device() DeviceInfo
+	// SetType sets a device type on the pool. this will make
+	// sure that the detected device type is reported
+	// correctly by calling the Type() method.
+	SetType(typ zos.DeviceType) error
+	// Type returns the device type set by a previous call
+	// to SetType.
+	Type() (zos.DeviceType, bool, error)
 }
 
 // Filter closure for Filesystem list

pkg/storage/storage.go

@@ -58,21 +58,15 @@ type Module struct {
 	mu sync.RWMutex
 
 	// cache is a cache directory can be used with some files
+	// NOTED: this is deprecated, now type is stored on the device
+	// itself not in temp cache
 	cache TypeCache
 }
 
 type TypeCache struct {
 	base string
 }
 
-func (t *TypeCache) Set(name string, typ pkg.DeviceType) error {
-	if err := os.WriteFile(filepath.Join(t.base, name), []byte(typ), 0644); err != nil {
-		return errors.Wrapf(err, "failed to store device type for '%s'", name)
-	}
-
-	return nil
-}
-
 func (t *TypeCache) Get(name string) (pkg.DeviceType, bool) {
 	data, err := os.ReadFile(filepath.Join(t.base, name))
 	if err != nil {
@@ -157,6 +151,50 @@ func (s *Module) dump() {
 
 }
 
+// poolType gets the device type of a disk
+func (s *Module) poolType(pool filesystem.Pool, vm bool) (zos.DeviceType, error) {
+	var typ zos.DeviceType
+	device := pool.Device()
+	// for development purposes only
+	if vm {
+		// force ssd device for vms
+		typ = zos.SSDDevice
+
+		if device.Path == "/dev/vdd" || device.Path == "/dev/vde" {
+			typ = zos.HDDDevice
+		}
+		return typ, nil
+	}
+
+	log.Debug().Str("device", device.Path).Msg("checking device type in disk")
+	typ, ok, err := pool.Type()
+	if err != nil {
+		return "", errors.Wrap(err, "failed to get device type")
+	}
+
+	if ok {
+		log.Debug().Str("device", device.Path).Str("type", typ.String()).Msg("device type loaded from disk")
+		return typ, nil
+	}
+
+	log.Debug().Str("device", device.Path).Msg("checking device type in cache")
+	typ, ok = s.cache.Get(device.Name())
+	if !ok {
+		log.Debug().Str("device", device.Path).Msg("detecting device type")
+		typ, err = device.DetectType()
+		if err != nil {
+			return "", errors.Wrap(err, "failed to detect device type")
+		}
+	}
+
+	log.Debug().Str("device", device.Path).Str("type", typ.String()).Msg("setting device type")
+	if err := pool.SetType(typ); err != nil {
+		return "", errors.Wrap(err, "failed to set device type")
+	}
+
+	return typ, nil
+}
+
 /*
 *
 initialize, must be called at least onetime each boot.
@@ -206,31 +244,11 @@ func (s *Module) initialize(ctx context.Context) error {
 			log.Error().Err(err).Str("pool", pool.Name()).Str("device", device.Path).Msg("failed to get usage of pool")
 		}
 
-		typ, ok := s.cache.Get(device.Name())
-		if !ok {
-			log.Debug().Str("device", device.Path).Msg("detecting device type")
-			typ, err = device.Type()
-			if err != nil {
-				log.Error().Str("device", device.Path).Err(err).Msg("failed to check device type")
-				continue
-			}
-
-			// for development purposes only
-			if vm {
-				// force ssd device for vms
-				typ = zos.SSDDevice
-
-				if device.Path == "/dev/vdd" || device.Path == "/dev/vde" {
-					typ = zos.HDDDevice
-				}
-			}
-
-			log.Debug().Str("device", device.Path).Str("type", typ.String()).Msg("caching device type")
-			if err := s.cache.Set(device.Name(), typ); err != nil {
-				log.Error().Str("device", device.Path).Err(err).Msg("failed to cache device type")
-			}
-		} else {
-			log.Debug().Str("device", device.Path).Str("type", typ.String()).Msg("device type loaded from cache")
+		typ, err := s.poolType(pool, vm)
+		if err != nil {
+			log.Error().Str("device", device.Path).Err(err).Msg("failed to get device type")
+			s.brokenDevices = append(s.brokenDevices, pkg.BrokenDevice{Path: device.Path, Err: err})
+			continue
 		}
 
 		switch typ {

pkg/storage/storage_test.go

@@ -91,8 +91,12 @@ func (p *testPool) UnMount() error {
 	return fmt.Errorf("UnMount not implemented")
 }
 
-func (p *testPool) Type() zos.DeviceType {
-	return p.ptype
+func (p *testPool) Type() (zos.DeviceType, bool, error) {
+	return p.ptype, false, nil
+}
+
+func (p *testPool) SetType(_ zos.DeviceType) error {
+	return nil
 }
 
 func (p *testPool) Volumes() ([]filesystem.Volume, error) {