fix: test build mount set to parent of current workspace

.github/workflows/test.yaml

@@ -30,6 +30,31 @@ jobs:
         with:
           build-mount-path: /var/lib/docker/tmp
 
+  test-mount-parent-of-workspace:
+    name: Test mounting the parent of GITHUB_WORKSPACE
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out Maximize Build Space action
+        uses: actions/checkout@v4
+        with:
+          path: ./.github/actions/maximize-test
+
+      - name: Calculate parent of workspace
+        id: workspace-parent
+        run: echo "parent=$(dirname "${GITHUB_WORKSPACE}")" >> "$GITHUB_OUTPUT"
+
+      - name: Maximize build space
+        uses: ./.github/actions/maximize-test
+        with:
+          build-mount-path: ${{ steps.workspace-parent.outputs.parent }}
+
+      - name: Create file in build folder as runner user (test ownership)
+        run: |
+          mkdir -p ${{ steps.workspace-parent.outputs.parent }}/new
+          touch ${{ steps.workspace-parent.outputs.parent }}/new/file.txt
+          touch ${GITHUB_WORKSPACE}/file.txt
+          ls -alR ${{ steps.workspace-parent.outputs.parent }}
+
   determine-free-space:
     name: Determine free space with different settings
     runs-on: ${{ matrix.os }}

action.yml

@@ -111,6 +111,9 @@ runs:
           fi
           echo
 
+          # store owner of $GITHUB_WORKSPACE in case the action deletes it
+          WORKSPACE_OWNER="$(stat -c '%U:%G' "${GITHUB_WORKSPACE}")"
+
           # ensure mount path exists before the action
           sudo mkdir -p "${BUILD_MOUNT_PATH}"
           sudo find "${BUILD_MOUNT_PATH}" -maxdepth 0 ! -empty -exec echo 'WARNING: directory [{}] is not empty, data loss might occur. Content:' \; -exec ls -al "{}" \;
@@ -182,8 +185,11 @@ runs:
           sudo mount "/dev/mapper/${VG_NAME}-buildlv" "${BUILD_MOUNT_PATH}"
           sudo chown -R "${{ inputs.build-mount-path-ownership }}" "${BUILD_MOUNT_PATH}"
 
-          # if build mount path is a parent of $GITHUB_WORKSPACE, recreate it
-          sudo mkdir -p "${GITHUB_WORKSPACE}"
+          # if build mount path is a parent of $GITHUB_WORKSPACE, and has been deleted, recreate it
+          if [[ ! -d "${GITHUB_WORKSPACE}" ]]; then
+            sudo mkdir -p "${GITHUB_WORKSPACE}"
+            sudo chown -R "${WORKSPACE_OWNER}" "${GITHUB_WORKSPACE}"
+          fi
 
     - name: Disk space report after modification
       shell: bash