fix: sidecar relative path joining

backend/meta/sidecar.go

@@ -49,6 +49,7 @@ func NewSideCar(dir string) (SideCar, error) {
 
 // RetrieveAttribute retrieves the value of a specific attribute for an object or a bucket.
 func (s SideCar) RetrieveAttribute(_ *os.File, bucket, object, attribute string) ([]byte, error) {
+	bucket, object = trimVolume(bucket), trimVolume(object)
 	metadir := filepath.Join(s.dir, bucket, object, sidecarmeta)
 	if object == "" {
 		metadir = filepath.Join(s.dir, bucket, sidecarmeta)
@@ -68,6 +69,7 @@ func (s SideCar) RetrieveAttribute(_ *os.File, bucket, object, attribute string)
 
 // StoreAttribute stores the value of a specific attribute for an object or a bucket.
 func (s SideCar) StoreAttribute(_ *os.File, bucket, object, attribute string, value []byte) error {
+	bucket, object = trimVolume(bucket), trimVolume(object)
 	metadir := filepath.Join(s.dir, bucket, object, sidecarmeta)
 	if object == "" {
 		metadir = filepath.Join(s.dir, bucket, sidecarmeta)
@@ -114,6 +116,7 @@ func (s SideCar) StoreAttribute(_ *os.File, bucket, object, attribute string, va
 
 // DeleteAttribute removes the value of a specific attribute for an object or a bucket.
 func (s SideCar) DeleteAttribute(bucket, object, attribute string) error {
+	bucket, object = trimVolume(bucket), trimVolume(object)
 	metadir := filepath.Join(s.dir, bucket, object, sidecarmeta)
 	if object == "" {
 		metadir = filepath.Join(s.dir, bucket, sidecarmeta)
@@ -135,6 +138,7 @@ func (s SideCar) DeleteAttribute(bucket, object, attribute string) error {
 
 // ListAttributes lists all attributes for an object or a bucket.
 func (s SideCar) ListAttributes(bucket, object string) ([]string, error) {
+	bucket, object = trimVolume(bucket), trimVolume(object)
 	metadir := filepath.Join(s.dir, bucket, object, sidecarmeta)
 	if object == "" {
 		metadir = filepath.Join(s.dir, bucket, sidecarmeta)
@@ -160,6 +164,7 @@ func (s SideCar) ListAttributes(bucket, object string) ([]string, error) {
 // When object is empty the entire bucket sidecar directory is removed,
 // cleaning up any orphaned object or multipart metadata within it.
 func (s SideCar) DeleteAttributes(bucket, object string) error {
+	bucket, object = trimVolume(bucket), trimVolume(object)
 	if object == "" {
 		// Remove the entire bucket sidecar directory so that orphaned
 		// object/multipart metadata does not accumulate after DeleteBucket.
@@ -184,8 +189,9 @@ func (s SideCar) DeleteAttributes(bucket, object string) error {
 // newObject so that path-based lookups continue to work after the data
 // directory has been renamed.
 func (s SideCar) RenameObject(bucket, oldObject, newObject string) error {
-	oldPath := filepath.Join(s.dir, bucket, oldObject)
-	newPath := filepath.Join(s.dir, bucket, newObject)
+	bucket = trimVolume(bucket)
+	oldPath := filepath.Join(s.dir, bucket, trimVolume(oldObject))
+	newPath := filepath.Join(s.dir, bucket, trimVolume(newObject))
 
 	if err := os.MkdirAll(filepath.Dir(newPath), 0777); err != nil {
 		if errors.Is(err, syscall.ENOSPC) {

backend/meta/sidecar_notwindows.go

@@ -0,0 +1,20 @@
+// Copyright 2025 Versity Software
+// This file is licensed under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+//go:build !windows
+
+package meta
+
+// trimVolume is a no-op on non-Windows platforms.
+func trimVolume(p string) string { return p }

backend/meta/sidecar_windows.go

@@ -0,0 +1,29 @@
+// Copyright 2025 Versity Software
+// This file is licensed under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+//go:build windows
+
+package meta
+
+import (
+	"path/filepath"
+	"strings"
+)
+
+// trimVolume strips the Windows drive letter (e.g. "C:") and any leading
+// path separator from p so it can be safely used as a sub-path component
+// inside filepath.Join without becoming an absolute root.
+func trimVolume(p string) string {
+	return strings.TrimLeft(p[len(filepath.VolumeName(p)):], `\/`)
+}

backend/posix/without_otmpfile.go

@@ -109,7 +109,7 @@ func (tmp *tmpfile) link() error {
 	backoffMs := initialBackoffMs
 	for {
 		err = backend.MoveFile(tempname, objPath, defaultFilePerm)
-		if !errors.Is(err, syscall.ENOENT) {
+		if !os.IsNotExist(err) {
 			break
 		}
 		// The parent directory may have been concurrently removed; backoff and retry.
@@ -117,11 +117,12 @@ func (tmp *tmpfile) link() error {
 		sleepWithJitter(backoffMs)
 		backoffMs = min((backoffMs * 2), maxBackoffMs)
 
-		err = backend.MkdirAll(filepath.Dir(objPath), tmp.uid, tmp.gid,
+		// Best-effort: recreate the parent directory. Ignore errors here;
+		// if recreation fails transiently (e.g. Windows pending-delete on
+		// a recently removed directory), the next MoveFile attempt will
+		// return os.IsNotExist again and we will retry.
+		_ = backend.MkdirAll(filepath.Dir(objPath), tmp.uid, tmp.gid,
 			tmp.doChown, tmp.newDirPerm)
-		if err != nil {
-			return fmt.Errorf("recreate parent dir: %w", err)
-		}
 	}
 	return err
 }