Merge pull request #105 from versity/ben/scoutfs_glacier

Ben/scoutfs glacier

backend/posix/posix.go

@@ -1031,19 +1031,7 @@ func (p *Posix) ListObjects(bucket, prefix, marker, delim string, maxkeys int) (
 
 	fileSystem := os.DirFS(bucket)
 	results, err := backend.Walk(fileSystem, prefix, delim, marker, maxkeys,
-		func(path string) (bool, error) {
-			_, err := xattr.Get(filepath.Join(bucket, path), etagkey)
-			if isNoAttr(err) {
-				return false, nil
-			}
-			if err != nil {
-				return false, err
-			}
-			return true, nil
-		}, func(path string) (string, error) {
-			etag, err := xattr.Get(filepath.Join(bucket, path), etagkey)
-			return string(etag), err
-		}, []string{metaTmpDir})
+		fileToObj(bucket), []string{metaTmpDir})
 	if err != nil {
 		return nil, fmt.Errorf("walk %v: %w", bucket, err)
 	}
@@ -1061,6 +1049,65 @@ func (p *Posix) ListObjects(bucket, prefix, marker, delim string, maxkeys int) (
 	}, nil
 }
 
+func fileToObj(bucket string) backend.GetObjFunc {
+	return func(path string, d fs.DirEntry) (types.Object, error) {
+		if d.IsDir() {
+			// directory object only happens if directory empty
+			// check to see if this is a directory object by checking etag
+			etagBytes, err := xattr.Get(filepath.Join(bucket, path), etagkey)
+			if isNoAttr(err) || errors.Is(err, fs.ErrNotExist) {
+				return types.Object{}, backend.ErrSkipObj
+			}
+			if err != nil {
+				return types.Object{}, fmt.Errorf("get etag: %w", err)
+			}
+			etag := string(etagBytes)
+
+			fi, err := d.Info()
+			if errors.Is(err, fs.ErrNotExist) {
+				return types.Object{}, backend.ErrSkipObj
+			}
+			if err != nil {
+				return types.Object{}, fmt.Errorf("get fileinfo: %w", err)
+			}
+
+			return types.Object{
+				ETag:         &etag,
+				Key:          &path,
+				LastModified: backend.GetTimePtr(fi.ModTime()),
+			}, nil
+		}
+
+		// file object, get object info and fill out object data
+		etagBytes, err := xattr.Get(filepath.Join(bucket, path), etagkey)
+		if errors.Is(err, fs.ErrNotExist) {
+			return types.Object{}, backend.ErrSkipObj
+		}
+		if err != nil && !isNoAttr(err) {
+			return types.Object{}, fmt.Errorf("get etag: %w", err)
+		}
+		// note: isNoAttr(err) will return etagBytes = []byte{}
+		// so this will just set etag to "" if its not already set
+
+		etag := string(etagBytes)
+
+		fi, err := d.Info()
+		if errors.Is(err, fs.ErrNotExist) {
+			return types.Object{}, backend.ErrSkipObj
+		}
+		if err != nil {
+			return types.Object{}, fmt.Errorf("get fileinfo: %w", err)
+		}
+
+		return types.Object{
+			ETag:         &etag,
+			Key:          &path,
+			LastModified: backend.GetTimePtr(fi.ModTime()),
+			Size:         fi.Size(),
+		}, nil
+	}
+}
+
 func (p *Posix) ListObjectsV2(bucket, prefix, marker, delim string, maxkeys int) (*s3.ListObjectsV2Output, error) {
 	_, err := os.Stat(bucket)
 	if errors.Is(err, fs.ErrNotExist) {
@@ -1072,19 +1119,7 @@ func (p *Posix) ListObjectsV2(bucket, prefix, marker, delim string, maxkeys int)
 
 	fileSystem := os.DirFS(bucket)
 	results, err := backend.Walk(fileSystem, prefix, delim, marker, maxkeys,
-		func(path string) (bool, error) {
-			_, err := xattr.Get(filepath.Join(bucket, path), etagkey)
-			if isNoAttr(err) {
-				return false, nil
-			}
-			if err != nil {
-				return false, err
-			}
-			return true, nil
-		}, func(path string) (string, error) {
-			etag, err := xattr.Get(filepath.Join(bucket, path), etagkey)
-			return string(etag), err
-		}, []string{metaTmpDir})
+		fileToObj(bucket), []string{metaTmpDir})
 	if err != nil {
 		return nil, fmt.Errorf("walk %v: %w", bucket, err)
 	}

backend/scoutfs/scoutfs.go

@@ -16,8 +16,10 @@ package scoutfs
 
 import (
 	"crypto/sha256"
+	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"io/fs"
 	"os"
 	"path/filepath"
@@ -37,6 +39,17 @@ type ScoutFS struct {
 	*posix.Posix
 	rootfd  *os.File
 	rootdir string
+
+	// glaciermode enables the following behavior:
+	// GET object:  if file offline, return invalid object state
+	// HEAD object: if file offline, set obj storage class to GLACIER
+	//              if file offline and staging, x-amz-restore: ongoing-request="true"
+	//              if file offline and not staging, x-amz-restore: ongoing-request="false"
+	//              if file online, x-amz-restore: ongoing-request="false", expiry-date="Fri, 2 Dec 2050 00:00:00 GMT"
+	//              note: this expiry-date is not used but provided for client glacier compatibility
+	// ListObjects: if file offline, set obj storage class to GLACIER
+	// RestoreObject: add batch stage request to file
+	glaciermode bool
 }
 
 var _ backend.Backend = &ScoutFS{}
@@ -44,11 +57,50 @@ var _ backend.Backend = &ScoutFS{}
 const (
 	metaTmpDir          = ".sgwtmp"
 	metaTmpMultipartDir = metaTmpDir + "/multipart"
-	onameAttr           = "user.objname"
 	tagHdr              = "X-Amz-Tagging"
 	emptyMD5            = "d41d8cd98f00b204e9800998ecf8427e"
+	etagkey             = "user.etag"
 )
 
+var (
+	stageComplete      = "ongoing-request=\"false\", expiry-date=\"Fri, 2 Dec 2050 00:00:00 GMT\""
+	stageInProgress    = "true"
+	stageNotInProgress = "false"
+)
+
+const (
+	// ScoutFS special xattr types
+
+	systemPrefix = "scoutfs.hide."
+	onameAttr    = systemPrefix + "objname"
+	flagskey     = systemPrefix + "sam_flags"
+	stagecopykey = systemPrefix + "sam_stagereq"
+)
+
+const (
+	// ScoutAM Flags
+
+	// Staging - file requested stage
+	Staging uint64 = 1 << iota
+	// StageFail - all copies failed to stage
+	StageFail
+	// NoArchive - no archive copies of file should be made
+	NoArchive
+	// ExtCacheRequested means file policy requests Ext Cache
+	ExtCacheRequested
+	// ExtCacheDone means this file ext cache copy has been
+	// created already (and possibly pruned, so may not exist)
+	ExtCacheDone
+)
+
+// Option sets various options for scoutfs
+type Option func(s *ScoutFS)
+
+// WithGlacierEmulation sets glacier mode emulation
+func WithGlacierEmulation() Option {
+	return func(s *ScoutFS) { s.glaciermode = true }
+}
+
 func (s *ScoutFS) Shutdown() {
 	s.Posix.Shutdown()
 	s.rootfd.Close()
@@ -62,7 +114,7 @@ func (*ScoutFS) String() string {
 // CompleteMultipartUpload scoutfs complete upload uses scoutfs move blocks
 // ioctl to not have to read and copy the part data to the final object. This
 // saves a read and write cycle for all mutlipart uploads.
-func (p *ScoutFS) CompleteMultipartUpload(bucket, object, uploadID string, parts []types.Part) (*s3.CompleteMultipartUploadOutput, error) {
+func (s *ScoutFS) CompleteMultipartUpload(bucket, object, uploadID string, parts []types.Part) (*s3.CompleteMultipartUploadOutput, error) {
 	_, err := os.Stat(bucket)
 	if errors.Is(err, fs.ErrNotExist) {
 		return nil, s3err.GetAPIError(s3err.ErrNoSuchBucket)
@@ -71,7 +123,7 @@ func (p *ScoutFS) CompleteMultipartUpload(bucket, object, uploadID string, parts
 		return nil, fmt.Errorf("stat bucket: %w", err)
 	}
 
-	sum, err := p.checkUploadIDExists(bucket, object, uploadID)
+	sum, err := s.checkUploadIDExists(bucket, object, uploadID)
 	if err != nil {
 		return nil, err
 	}
@@ -185,7 +237,7 @@ func (p *ScoutFS) CompleteMultipartUpload(bucket, object, uploadID string, parts
 	}, nil
 }
 
-func (p *ScoutFS) checkUploadIDExists(bucket, object, uploadID string) ([32]byte, error) {
+func (s *ScoutFS) checkUploadIDExists(bucket, object, uploadID string) ([32]byte, error) {
 	sum := sha256.Sum256([]byte(object))
 	objdir := filepath.Join(bucket, metaTmpMultipartDir, fmt.Sprintf("%x", sum))
 
@@ -294,3 +346,398 @@ func mkdirAll(path string, perm os.FileMode, bucket, object string) error {
 	}
 	return nil
 }
+
+func (s *ScoutFS) HeadObject(bucket, object string) (*s3.HeadObjectOutput, error) {
+	_, err := os.Stat(bucket)
+	if errors.Is(err, fs.ErrNotExist) {
+		return nil, s3err.GetAPIError(s3err.ErrNoSuchBucket)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("stat bucket: %w", err)
+	}
+
+	objPath := filepath.Join(bucket, object)
+	fi, err := os.Stat(objPath)
+	if errors.Is(err, fs.ErrNotExist) {
+		return nil, s3err.GetAPIError(s3err.ErrNoSuchKey)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("stat object: %w", err)
+	}
+
+	userMetaData := make(map[string]string)
+	contentType, contentEncoding := loadUserMetaData(objPath, userMetaData)
+
+	b, err := xattr.Get(objPath, etagkey)
+	etag := string(b)
+	if err != nil {
+		etag = ""
+	}
+
+	stclass := types.StorageClassStandard
+	requestOngoing := ""
+	if s.glaciermode {
+		requestOngoing = stageComplete
+
+		// Check if there are any offline exents associated with this file.
+		// If so, we will set storage class to glacier.
+		st, err := scoutfs.StatMore(objPath)
+		if errors.Is(err, fs.ErrNotExist) {
+			return nil, s3err.GetAPIError(s3err.ErrNoSuchKey)
+		}
+		if err != nil {
+			return nil, fmt.Errorf("stat more: %w", err)
+		}
+		if st.Offline_blocks != 0 {
+			stclass = types.StorageClassGlacier
+			requestOngoing = stageNotInProgress
+
+			ok, err := isStaging(objPath)
+			if errors.Is(err, fs.ErrNotExist) {
+				return nil, s3err.GetAPIError(s3err.ErrNoSuchKey)
+			}
+			if err != nil {
+				return nil, fmt.Errorf("check stage status: %w", err)
+			}
+			if ok {
+				requestOngoing = stageInProgress
+			}
+		}
+	}
+
+	return &s3.HeadObjectOutput{
+		ContentLength:   fi.Size(),
+		ContentType:     &contentType,
+		ContentEncoding: &contentEncoding,
+		ETag:            &etag,
+		LastModified:    backend.GetTimePtr(fi.ModTime()),
+		Metadata:        userMetaData,
+		StorageClass:    stclass,
+		Restore:         &requestOngoing,
+	}, nil
+}
+
+func (s *ScoutFS) GetObject(bucket, object, acceptRange string, writer io.Writer) (*s3.GetObjectOutput, error) {
+	_, err := os.Stat(bucket)
+	if errors.Is(err, fs.ErrNotExist) {
+		return nil, s3err.GetAPIError(s3err.ErrNoSuchBucket)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("stat bucket: %w", err)
+	}
+
+	objPath := filepath.Join(bucket, object)
+	fi, err := os.Stat(objPath)
+	if errors.Is(err, fs.ErrNotExist) {
+		return nil, s3err.GetAPIError(s3err.ErrNoSuchKey)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("stat object: %w", err)
+	}
+
+	startOffset, length, err := backend.ParseRange(fi, acceptRange)
+	if err != nil {
+		return nil, err
+	}
+
+	if startOffset+length > fi.Size() {
+		// TODO: is ErrInvalidRequest correct here?
+		return nil, s3err.GetAPIError(s3err.ErrInvalidRequest)
+	}
+
+	if s.glaciermode {
+		// Check if there are any offline exents associated with this file.
+		// If so, we will return the InvalidObjectState error.
+		st, err := scoutfs.StatMore(objPath)
+		if errors.Is(err, fs.ErrNotExist) {
+			return nil, s3err.GetAPIError(s3err.ErrNoSuchKey)
+		}
+		if err != nil {
+			return nil, fmt.Errorf("stat more: %w", err)
+		}
+		if st.Offline_blocks != 0 {
+			return nil, s3err.GetAPIError(s3err.ErrInvalidObjectState)
+		}
+	}
+
+	f, err := os.Open(objPath)
+	if errors.Is(err, fs.ErrNotExist) {
+		return nil, s3err.GetAPIError(s3err.ErrNoSuchKey)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("open object: %w", err)
+	}
+	defer f.Close()
+
+	rdr := io.NewSectionReader(f, startOffset, length)
+	_, err = io.Copy(writer, rdr)
+	if err != nil {
+		return nil, fmt.Errorf("copy data: %w", err)
+	}
+
+	userMetaData := make(map[string]string)
+
+	contentType, contentEncoding := loadUserMetaData(objPath, userMetaData)
+
+	b, err := xattr.Get(objPath, etagkey)
+	etag := string(b)
+	if err != nil {
+		etag = ""
+	}
+
+	tags, err := s.getXattrTags(bucket, object)
+	if err != nil {
+		return nil, fmt.Errorf("get object tags: %w", err)
+	}
+
+	return &s3.GetObjectOutput{
+		AcceptRanges:    &acceptRange,
+		ContentLength:   length,
+		ContentEncoding: &contentEncoding,
+		ContentType:     &contentType,
+		ETag:            &etag,
+		LastModified:    backend.GetTimePtr(fi.ModTime()),
+		Metadata:        userMetaData,
+		TagCount:        int32(len(tags)),
+		StorageClass:    types.StorageClassStandard,
+	}, nil
+}
+
+func (s *ScoutFS) getXattrTags(bucket, object string) (map[string]string, error) {
+	tags := make(map[string]string)
+	b, err := xattr.Get(filepath.Join(bucket, object), "user."+tagHdr)
+	if errors.Is(err, fs.ErrNotExist) {
+		return nil, s3err.GetAPIError(s3err.ErrNoSuchKey)
+	}
+	if isNoAttr(err) {
+		return tags, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("get tags: %w", err)
+	}
+
+	err = json.Unmarshal(b, &tags)
+	if err != nil {
+		return nil, fmt.Errorf("unmarshal tags: %w", err)
+	}
+
+	return tags, nil
+}
+
+func (s *ScoutFS) ListObjects(bucket, prefix, marker, delim string, maxkeys int) (*s3.ListObjectsOutput, error) {
+	_, err := os.Stat(bucket)
+	if errors.Is(err, fs.ErrNotExist) {
+		return nil, s3err.GetAPIError(s3err.ErrNoSuchBucket)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("stat bucket: %w", err)
+	}
+
+	fileSystem := os.DirFS(bucket)
+	results, err := backend.Walk(fileSystem, prefix, delim, marker, maxkeys,
+		s.fileToObj(bucket), []string{metaTmpDir})
+	if err != nil {
+		return nil, fmt.Errorf("walk %v: %w", bucket, err)
+	}
+
+	return &s3.ListObjectsOutput{
+		CommonPrefixes: results.CommonPrefixes,
+		Contents:       results.Objects,
+		Delimiter:      &delim,
+		IsTruncated:    results.Truncated,
+		Marker:         &marker,
+		MaxKeys:        int32(maxkeys),
+		Name:           &bucket,
+		NextMarker:     &results.NextMarker,
+		Prefix:         &prefix,
+	}, nil
+}
+
+func (s *ScoutFS) ListObjectsV2(bucket, prefix, marker, delim string, maxkeys int) (*s3.ListObjectsV2Output, error) {
+	_, err := os.Stat(bucket)
+	if errors.Is(err, fs.ErrNotExist) {
+		return nil, s3err.GetAPIError(s3err.ErrNoSuchBucket)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("stat bucket: %w", err)
+	}
+
+	fileSystem := os.DirFS(bucket)
+	results, err := backend.Walk(fileSystem, prefix, delim, marker, maxkeys,
+		s.fileToObj(bucket), []string{metaTmpDir})
+	if err != nil {
+		return nil, fmt.Errorf("walk %v: %w", bucket, err)
+	}
+
+	return &s3.ListObjectsV2Output{
+		CommonPrefixes:        results.CommonPrefixes,
+		Contents:              results.Objects,
+		Delimiter:             &delim,
+		IsTruncated:           results.Truncated,
+		ContinuationToken:     &marker,
+		MaxKeys:               int32(maxkeys),
+		Name:                  &bucket,
+		NextContinuationToken: &results.NextMarker,
+		Prefix:                &prefix,
+	}, nil
+}
+
+func (s *ScoutFS) fileToObj(bucket string) backend.GetObjFunc {
+	return func(path string, d fs.DirEntry) (types.Object, error) {
+		objPath := filepath.Join(bucket, path)
+		if d.IsDir() {
+			// directory object only happens if directory empty
+			// check to see if this is a directory object by checking etag
+			etagBytes, err := xattr.Get(objPath, etagkey)
+			if isNoAttr(err) || errors.Is(err, fs.ErrNotExist) {
+				return types.Object{}, backend.ErrSkipObj
+			}
+			if err != nil {
+				return types.Object{}, fmt.Errorf("get etag: %w", err)
+			}
+			etag := string(etagBytes)
+
+			fi, err := d.Info()
+			if errors.Is(err, fs.ErrNotExist) {
+				return types.Object{}, backend.ErrSkipObj
+			}
+			if err != nil {
+				return types.Object{}, fmt.Errorf("get fileinfo: %w", err)
+			}
+
+			return types.Object{
+				ETag:         &etag,
+				Key:          &path,
+				LastModified: backend.GetTimePtr(fi.ModTime()),
+			}, nil
+		}
+
+		// file object, get object info and fill out object data
+		etagBytes, err := xattr.Get(objPath, etagkey)
+		if errors.Is(err, fs.ErrNotExist) {
+			return types.Object{}, backend.ErrSkipObj
+		}
+		if err != nil && !isNoAttr(err) {
+			return types.Object{}, fmt.Errorf("get etag: %w", err)
+		}
+		etag := string(etagBytes)
+
+		fi, err := d.Info()
+		if errors.Is(err, fs.ErrNotExist) {
+			return types.Object{}, backend.ErrSkipObj
+		}
+		if err != nil {
+			return types.Object{}, fmt.Errorf("get fileinfo: %w", err)
+		}
+
+		sc := types.ObjectStorageClassStandard
+		if s.glaciermode {
+			// Check if there are any offline exents associated with this file.
+			// If so, we will return the InvalidObjectState error.
+			st, err := scoutfs.StatMore(objPath)
+			if errors.Is(err, fs.ErrNotExist) {
+				return types.Object{}, backend.ErrSkipObj
+			}
+			if err != nil {
+				return types.Object{}, fmt.Errorf("stat more: %w", err)
+			}
+			if st.Offline_blocks != 0 {
+				sc = types.ObjectStorageClassGlacier
+			}
+		}
+
+		return types.Object{
+			ETag:         &etag,
+			Key:          &path,
+			LastModified: backend.GetTimePtr(fi.ModTime()),
+			Size:         fi.Size(),
+			StorageClass: sc,
+		}, nil
+	}
+}
+
+// RestoreObject will set stage request on file if offline and do nothing if
+// file is online
+func (s *ScoutFS) RestoreObject(bucket, object string, restoreRequest *s3.RestoreObjectInput) error {
+	_, err := os.Stat(bucket)
+	if errors.Is(err, fs.ErrNotExist) {
+		return s3err.GetAPIError(s3err.ErrNoSuchBucket)
+	}
+	if err != nil {
+		return fmt.Errorf("stat bucket: %w", err)
+	}
+
+	err = setStaging(filepath.Join(bucket, object))
+	if errors.Is(err, fs.ErrNotExist) {
+		return s3err.GetAPIError(s3err.ErrNoSuchKey)
+	}
+	if err != nil {
+		return fmt.Errorf("stage object: %w", err)
+	}
+
+	return nil
+}
+
+func setStaging(objname string) error {
+	b, err := xattr.Get(objname, flagskey)
+	if err != nil && !isNoAttr(err) {
+		return err
+	}
+
+	var oldflags uint64
+	if !isNoAttr(err) {
+		err = json.Unmarshal(b, &oldflags)
+		if err != nil {
+			return err
+		}
+	}
+
+	newflags := oldflags | Staging
+
+	if newflags == oldflags {
+		// no flags change, just return
+		return nil
+	}
+
+	return fSetNewGlobalFlags(objname, newflags)
+}
+
+func isStaging(objname string) (bool, error) {
+	b, err := xattr.Get(objname, flagskey)
+	if err != nil && !isNoAttr(err) {
+		return false, err
+	}
+
+	var flags uint64
+	if !isNoAttr(err) {
+		err = json.Unmarshal(b, &flags)
+		if err != nil {
+			return false, err
+		}
+	}
+
+	return flags&Staging == Staging, nil
+}
+
+func fSetNewGlobalFlags(objname string, flags uint64) error {
+	b, err := json.Marshal(&flags)
+	if err != nil {
+		return err
+	}
+
+	return xattr.Set(objname, flagskey, b)
+}
+
+func isNoAttr(err error) bool {
+	if err == nil {
+		return false
+	}
+	xerr, ok := err.(*xattr.Error)
+	if ok && xerr.Err == xattr.ENOATTR {
+		return true
+	}
+	if err == syscall.ENODATA {
+		return true
+	}
+	return false
+}

backend/scoutfs/scoutfs_darwin.go

@@ -20,7 +20,7 @@ import (
 	"os"
 )
 
-func New(rootdir string) (*ScoutFS, error) {
+func New(rootdir string, opts ...Option) (*ScoutFS, error) {
 	return nil, fmt.Errorf("scoutfs only available on linux")
 }
 

backend/scoutfs/scoutfs_linux.go

@@ -29,7 +29,7 @@ import (
 	"github.com/versity/versitygw/backend/posix"
 )
 
-func New(rootdir string) (*ScoutFS, error) {
+func New(rootdir string, opts ...Option) (*ScoutFS, error) {
 	p, err := posix.New(rootdir)
 	if err != nil {
 		return nil, err
@@ -40,7 +40,12 @@ func New(rootdir string) (*ScoutFS, error) {
 		return nil, fmt.Errorf("open %v: %w", rootdir, err)
 	}
 
-	return &ScoutFS{Posix: p, rootfd: f, rootdir: rootdir}, nil
+	s := &ScoutFS{Posix: p, rootfd: f, rootdir: rootdir}
+	for _, opt := range opts {
+		opt(s)
+	}
+
+	return s, nil
 }
 
 const procfddir = "/proc/self/fd"

backend/scoutfs/scoutfs_windows.go

@@ -20,7 +20,7 @@ import (
 	"os"
 )
 
-func New(rootdir string) (*ScoutFS, error) {
+func New(rootdir string, opts ...Option) (*ScoutFS, error) {
 	return nil, fmt.Errorf("scoutfs only available on linux")
 }
 

backend/walk.go

@@ -15,6 +15,7 @@
 package backend
 
 import (
+	"errors"
 	"fmt"
 	"io/fs"
 	"os"
@@ -31,12 +32,13 @@ type WalkResults struct {
 	NextMarker     string
 }
 
-type DirObjCheck func(path string) (bool, error)
-type GetETag func(path string) (string, error)
+type GetObjFunc func(path string, d fs.DirEntry) (types.Object, error)
+
+var ErrSkipObj = errors.New("skip this object")
 
 // Walk walks the supplied fs.FS and returns results compatible with list
 // objects responses
-func Walk(fileSystem fs.FS, prefix, delimiter, marker string, max int, dirchk DirObjCheck, getetag GetETag, skipdirs []string) (WalkResults, error) {
+func Walk(fileSystem fs.FS, prefix, delimiter, marker string, max int, getObj GetObjFunc, skipdirs []string) (WalkResults, error) {
 	cpmap := make(map[string]struct{})
 	var objects []types.Object
 
@@ -90,26 +92,14 @@ func Walk(fileSystem fs.FS, prefix, delimiter, marker string, max int, dirchk Di
 				return fmt.Errorf("readdir %q: %w", path, err)
 			}
 			if len(ents) == 0 {
-				dirobj, err := dirchk(path)
+				dirobj, err := getObj(path, d)
+				if err == ErrSkipObj {
+					return nil
+				}
 				if err != nil {
-					return fmt.Errorf("directory object check %q: %w", path, err)
-				}
-				if dirobj {
-					fi, err := d.Info()
-					if err != nil {
-						return fmt.Errorf("dir info %q: %w", path, err)
-					}
-					etag, err := getetag(path)
-					if err != nil {
-						return fmt.Errorf("get etag %q: %w", path, err)
-					}
-					path := path + "/"
-					objects = append(objects, types.Object{
-						ETag:         &etag,
-						Key:          &path,
-						LastModified: GetTimePtr(fi.ModTime()),
-					})
+					return fmt.Errorf("directory to object %q: %w", path, err)
 				}
+				objects = append(objects, dirobj)
 			}
 
 			return nil
@@ -130,21 +120,14 @@ func Walk(fileSystem fs.FS, prefix, delimiter, marker string, max int, dirchk Di
 		if delimiter == "" {
 			// If no delimeter specified, then all files with matching
 			// prefix are included in results
-			fi, err := d.Info()
-			if err != nil {
-				return fmt.Errorf("get info for %v: %w", path, err)
+			obj, err := getObj(path, d)
+			if err == ErrSkipObj {
+				return nil
 			}
-			etag, err := getetag(path)
 			if err != nil {
-				return fmt.Errorf("get etag %q: %w", path, err)
+				return fmt.Errorf("file to object %q: %w", path, err)
 			}
-
-			objects = append(objects, types.Object{
-				ETag:         &etag,
-				Key:          &path,
-				LastModified: GetTimePtr(fi.ModTime()),
-				Size:         fi.Size(),
-			})
+			objects = append(objects, obj)
 
 			if max > 0 && (len(objects)+len(cpmap)) == max {
 				pastMax = true
@@ -177,20 +160,14 @@ func Walk(fileSystem fs.FS, prefix, delimiter, marker string, max int, dirchk Di
 		suffix := strings.TrimPrefix(path, prefix)
 		before, _, found := strings.Cut(suffix, delimiter)
 		if !found {
-			fi, err := d.Info()
-			if err != nil {
-				return fmt.Errorf("get info for %v: %w", path, err)
+			obj, err := getObj(path, d)
+			if err == ErrSkipObj {
+				return nil
 			}
-			etag, err := getetag(path)
 			if err != nil {
-				return fmt.Errorf("get etag %q: %w", path, err)
+				return fmt.Errorf("file to object %q: %w", path, err)
 			}
-			objects = append(objects, types.Object{
-				ETag:         &etag,
-				Key:          &path,
-				LastModified: GetTimePtr(fi.ModTime()),
-				Size:         fi.Size(),
-			})
+			objects = append(objects, obj)
 			if (len(objects) + len(cpmap)) == max {
 				pastMax = true
 			}

backend/walk_test.go

@@ -15,6 +15,9 @@
 package backend_test
 
 import (
+	"crypto/md5"
+	"encoding/hex"
+	"fmt"
 	"io/fs"
 	"testing"
 	"testing/fstest"
@@ -26,10 +29,44 @@ import (
 type walkTest struct {
 	fsys     fs.FS
 	expected backend.WalkResults
-	dc       backend.DirObjCheck
+	getobj   backend.GetObjFunc
 }
 
-func gettag(string) (string, error) { return "myetag", nil }
+func getObj(path string, d fs.DirEntry) (types.Object, error) {
+	if d.IsDir() {
+		etag := getMD5(path)
+
+		fi, err := d.Info()
+		if err != nil {
+			return types.Object{}, fmt.Errorf("get fileinfo: %w", err)
+		}
+
+		return types.Object{
+			ETag:         &etag,
+			Key:          &path,
+			LastModified: backend.GetTimePtr(fi.ModTime()),
+		}, nil
+	}
+
+	etag := getMD5(path)
+
+	fi, err := d.Info()
+	if err != nil {
+		return types.Object{}, fmt.Errorf("get fileinfo: %w", err)
+	}
+
+	return types.Object{
+		ETag:         &etag,
+		Key:          &path,
+		LastModified: backend.GetTimePtr(fi.ModTime()),
+		Size:         fi.Size(),
+	}, nil
+}
+
+func getMD5(text string) string {
+	hash := md5.Sum([]byte(text))
+	return hex.EncodeToString(hash[:])
+}
 
 func TestWalk(t *testing.T) {
 	tests := []walkTest{
@@ -51,7 +88,7 @@ func TestWalk(t *testing.T) {
 					Key: backend.GetStringPtr("sample.jpg"),
 				}},
 			},
-			dc: func(string) (bool, error) { return false, nil },
+			getobj: getObj,
 		},
 		{
 			// test case single dir/single file
@@ -64,12 +101,12 @@ func TestWalk(t *testing.T) {
 				}},
 				Objects: []types.Object{},
 			},
-			dc: func(string) (bool, error) { return true, nil },
+			getobj: getObj,
 		},
 	}
 
 	for _, tt := range tests {
-		res, err := backend.Walk(tt.fsys, "", "/", "", 1000, tt.dc, gettag, []string{})
+		res, err := backend.Walk(tt.fsys, "", "/", "", 1000, tt.getobj, []string{})
 		if err != nil {
 			t.Fatalf("walk: %v", err)
 		}

cmd/versitygw/scoutfs.go

@@ -21,6 +21,10 @@ import (
 	"github.com/versity/versitygw/backend/scoutfs"
 )
 
+var (
+	glacier bool
+)
+
 func scoutfsCommand() *cli.Command {
 	return &cli.Command{
 		Name:  "scoutfs",
@@ -39,6 +43,14 @@ will be translated into the file /mnt/fs/gwroot/mybucket/a/b/c/myobject
 ScoutFS contains optimizations for multipart uploads using extent
 move interfaces as well as support for tiered filesystems.`,
 		Action: runScoutfs,
+		Flags: []cli.Flag{
+			&cli.BoolFlag{
+				Name:        "glacier",
+				Usage:       "enable glacier emulation mode",
+				Aliases:     []string{"g"},
+				Destination: &glacier,
+			},
+		},
 	}
 }
 
@@ -47,7 +59,12 @@ func runScoutfs(ctx *cli.Context) error {
 		return fmt.Errorf("no directory provided for operation")
 	}
 
-	be, err := scoutfs.New(ctx.Args().Get(0))
+	var opts []scoutfs.Option
+	if glacier {
+		opts = append(opts, scoutfs.WithGlacierEmulation())
+	}
+
+	be, err := scoutfs.New(ctx.Args().Get(0), opts...)
 	if err != nil {
 		return fmt.Errorf("init scoutfs: %v", err)
 	}

s3api/controllers/base.go

@@ -148,6 +148,10 @@ func (c S3ApiController) GetActions(ctx *fiber.Ctx) error {
 			Key:   "Last-Modified",
 			Value: lastmod,
 		},
+		{
+			Key:   "x-amz-storage-class",
+			Value: string(res.StorageClass),
+		},
 	})
 	return SendResponse(ctx, err)
 }
@@ -571,6 +575,14 @@ func (c S3ApiController) HeadObject(ctx *fiber.Ctx) error {
 			Key:   "Last-Modified",
 			Value: lastmod,
 		},
+		{
+			Key:   "x-amz-storage-class",
+			Value: string(res.StorageClass),
+		},
+		{
+			Key:   "x-amz-restore",
+			Value: getstring(res.Restore),
+		},
 	})
 
 	return SendResponse(ctx, nil)

s3err/s3err.go

@@ -105,6 +105,7 @@ const (
 	ErrAuthNotSetup
 	ErrNotImplemented
 	ErrPreconditionFailed
+	ErrInvalidObjectState
 
 	ErrExistingObjectIsDirectory
 	ErrObjectParentIsFile
@@ -368,6 +369,11 @@ var errorCodeResponse = map[ErrorCode]APIError{
 		Description:    "At least one of the pre-conditions you specified did not hold",
 		HTTPStatusCode: http.StatusPreconditionFailed,
 	},
+	ErrInvalidObjectState: {
+		Code:           "InvalidObjectState",
+		Description:    "The operation is not valid for the current state of the object",
+		HTTPStatusCode: http.StatusForbidden,
+	},
 	ErrExistingObjectIsDirectory: {
 		Code:           "ExistingObjectIsDirectory",
 		Description:    "Existing Object is a directory.",