feat: add real size to backing image

ref: longhorn/longhorn 8757

Signed-off-by: Jack Lin <jack.lin@suse.com>

api/types.go

@@ -13,6 +13,7 @@ type BackingImage struct {
 	UUID             string `json:"uuid"`
 	Size             int64  `json:"size"`
 	VirtualSize      int64  `json:"virtualSize"`
+	RealSize         int64  `json:"realSize"`
 	ExpectedChecksum string `json:"expectedChecksum"`
 
 	Status BackingImageStatus `json:"status"`
@@ -33,6 +34,7 @@ func RPCToBackingImage(obj *rpc.BackingImageResponse) *BackingImage {
 		UUID:             obj.Spec.Uuid,
 		Size:             obj.Spec.Size,
 		VirtualSize:      obj.Spec.VirtualSize,
+		RealSize:         obj.Spec.RealSize,
 		ExpectedChecksum: obj.Spec.Checksum,
 
 		Status: BackingImageStatus{
@@ -114,6 +116,7 @@ type FileInfo struct {
 	UUID             string `json:"uuid"`
 	Size             int64  `json:"size"`
 	VirtualSize      int64  `json:"virtualSize"`
+	RealSize         int64  `json:"realSize"`
 	State            string `json:"state"`
 	Progress         int    `json:"progress"`
 	ProcessedSize    int64  `json:"processedSize"`

go.mod

@@ -4,6 +4,8 @@ go 1.22.2
 
 toolchain go1.23.0
 
+replace github.com/longhorn/types v0.0.0-20240725040629-473d671316c4 => github.com/chanyilin/types v0.0.0-20240827082245-b720128c87f4
+
 require (
 	github.com/golang/protobuf v1.5.4
 	github.com/gorilla/mux v1.8.1

go.sum

@@ -24,6 +24,8 @@ github.com/c9s/goprocinfo v0.0.0-20210130143923-c95fcf8c64a8 h1:SjZ2GvvOononHOpK
 github.com/c9s/goprocinfo v0.0.0-20210130143923-c95fcf8c64a8/go.mod h1:uEyr4WpAH4hio6LFriaPkL938XnrvLpNPmQHBdrmbIE=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/chanyilin/types v0.0.0-20240827082245-b720128c87f4 h1:owlhqpqY7n3UV4U+T0E0olMGKVxoVCL/Xuye9BTHKKA=
+github.com/chanyilin/types v0.0.0-20240827082245-b720128c87f4/go.mod h1:KlJuZB8NfHchWshYxYgV9pPIxBKC04Vq05G2TfgMf7w=
 github.com/coreos/go-systemd/v22 v22.5.0 h1:RrqgGjYQKalulkV8NGVIfkXQf6YYmOyiJKk8iXXhfZs=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/cpuguy83/go-md2man/v2 v2.0.4 h1:wfIWP927BUkWJb2NmU/kNDYIBTh/ziUX91+lVfRxZq4=
@@ -82,8 +84,6 @@ github.com/longhorn/longhorn-engine v1.5.5 h1:44p9Iyp4boKSHgMAl8iD4nY/EQRnF/e7hP
 github.com/longhorn/longhorn-engine v1.5.5/go.mod h1:/QEAmYu1ZNsKR22d8wdqssbz1ja7Yyj/GyPu8BYkTEk=
 github.com/longhorn/sparse-tools v0.0.0-20240729132735-18b207e459ff h1:gmdQDbnaGJ/zmrK+QJzSys8mH679os6i7vW/pOpRn1U=
 github.com/longhorn/sparse-tools v0.0.0-20240729132735-18b207e459ff/go.mod h1:iUJCZtOKG/9xv2rfrUAYZntFTzP5dZtvy4Kwe6dMcUc=
-github.com/longhorn/types v0.0.0-20240725040629-473d671316c4 h1:L2g0sIJ2fXt4BSFRYNnF6ObtKryCUFm9qLcCXHWssCk=
-github.com/longhorn/types v0.0.0-20240725040629-473d671316c4/go.mod h1:KlJuZB8NfHchWshYxYgV9pPIxBKC04Vq05G2TfgMf7w=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
 github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=

pkg/manager/service.go

@@ -300,6 +300,7 @@ func backingImageResponse(fInfo *api.FileInfo) *rpc.BackingImageResponse {
 			Uuid:        fInfo.UUID,
 			Size:        fInfo.Size,
 			VirtualSize: fInfo.VirtualSize,
+			RealSize:    fInfo.RealSize,
 			Checksum:    fInfo.ExpectedChecksum,
 		},
 		Status: &rpc.BackingImageStatus{

pkg/sync/sync_file.go

@@ -85,6 +85,7 @@ type SyncingFile struct {
 	diskUUID         string
 	size             int64
 	virtualSize      int64
+	realSize         int64
 	state            types.State
 	progress         int
 	processedSize    int64
@@ -258,6 +259,7 @@ func (sf *SyncingFile) checkAndReuseFile() (err error) {
 	sf.modificationTime = info.ModTime().UTC().String()
 	sf.updateSyncReadyNoLock()
 	sf.updateVirtualSizeNoLock(sf.filePath)
+	sf.updateRealSizeNoLock(sf.filePath)
 	sf.writeConfigNoLock()
 	sf.lock.Unlock()
 
@@ -359,6 +361,7 @@ func (sf *SyncingFile) getNoLock() api.FileInfo {
 		UUID:             sf.uuid,
 		Size:             sf.size,
 		VirtualSize:      sf.virtualSize,
+		RealSize:         sf.realSize,
 		State:            string(sf.state),
 		Progress:         sf.progress,
 		ProcessedSize:    sf.processedSize,
@@ -917,6 +920,7 @@ func (sf *SyncingFile) finishProcessing(err error) (finalErr error) {
 		sf.currentChecksum = config.CurrentChecksum
 		sf.updateSyncReadyNoLock()
 		sf.updateVirtualSizeNoLock(sf.tmpFilePath)
+		sf.updateRealSizeNoLock(sf.tmpFilePath)
 		sf.writeConfigNoLock()
 
 		// Renaming won't change the file modification time.
@@ -966,6 +970,7 @@ func (sf *SyncingFile) postProcessSyncFile() {
 	}
 	sf.updateSyncReadyNoLock()
 	sf.updateVirtualSizeNoLock(sf.tmpFilePath)
+	sf.updateRealSizeNoLock(sf.tmpFilePath)
 	sf.writeConfigNoLock()
 
 	// Renaming won't change the file modification time.
@@ -1000,6 +1005,18 @@ func (sf *SyncingFile) updateVirtualSizeNoLock(filePath string) {
 	sf.virtualSize = imgInfo.VirtualSize
 }
 
+func (sf *SyncingFile) updateRealSizeNoLock(filePath string) {
+	realSize, err := util.GetFileRealSize(filePath)
+	if err != nil {
+		sf.log.Warnf("SyncingFile: failed to get backing image virtual size: %v", err)
+	}
+
+	// This will be zero when there is an error, which allows components
+	// further up the stack to know that the real size somehow isn't
+	// available yet.
+	sf.realSize = realSize
+}
+
 func (sf *SyncingFile) handleFailureNoLock(err error) {
 	if err == nil {
 		return
@@ -1029,6 +1046,7 @@ func (sf *SyncingFile) writeConfigNoLock() {
 		UUID:             sf.uuid,
 		Size:             sf.size,
 		VirtualSize:      sf.virtualSize,
+		RealSize:         sf.realSize,
 		ExpectedChecksum: sf.expectedChecksum,
 		CurrentChecksum:  sf.currentChecksum,
 		ModificationTime: sf.modificationTime,

pkg/util/util.go

@@ -14,6 +14,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"regexp"
+	"syscall"
 	"time"
 
 	"github.com/pkg/errors"
@@ -151,6 +152,7 @@ type SyncingFileConfig struct {
 	UUID             string `json:"uuid"`
 	Size             int64  `json:"size"`
 	VirtualSize      int64  `json:"virtualSize"`
+	RealSize         int64  `json:"realSize"`
 	ExpectedChecksum string `json:"expectedChecksum"`
 	CurrentChecksum  string `json:"currentChecksum"`
 	ModificationTime string `json:"modificationTime"`
@@ -313,6 +315,18 @@ func ConvertFromQcow2ToRaw(sourcePath, targetPath string) error {
 	return nil
 }
 
+func GetFileRealSize(filePath string) (int64, error) {
+	var stat syscall.Stat_t
+	err := syscall.Stat(filePath, &stat)
+	if err != nil {
+		return 0, err
+	}
+	fmt.Printf("stat.Blksize: %v\n", stat.Blksize)
+
+	// 512 is defined in the Linux kernel and remains consistent across all distributions.
+	return stat.Blocks * 512, nil
+}
+
 func FileModificationTime(filePath string) string {
 	fi, err := os.Stat(filePath)
 	if err != nil {