Handle broken pipe when destination is full

Author: basnijholt

rsync_time_machine.py

@@ -694,14 +694,27 @@ def deal_with_no_space_left(
     auto_expire: bool,
 ) -> bool:
     """Deal with no space left on device."""
-    with open(log_file) as f:
+    with open(log_file, encoding="utf-8", errors="replace") as f:
         log_data = f.read()
 
     no_space_left = re.search(
         r"No space left on device \(28\)|Result too large \(34\)",
         log_data,
     )
 
+    if not no_space_left and re.search(r"rsync: \[sender\] write error: Broken pipe \(32\)", log_data):
+        df_result = run_cmd(f"df -Pk '{dest_folder}'", dest_is_ssh(ssh))
+        if df_result.returncode == 0:
+            lines = df_result.stdout.splitlines()
+            if len(lines) > 1:
+                try:
+                    available_blocks = int(lines[1].split()[3])
+                except (IndexError, ValueError):
+                    pass
+                else:
+                    if available_blocks <= 0:
+                        no_space_left = True
+
     if no_space_left:
         if not auto_expire:
             log_error(
@@ -727,7 +740,7 @@ def check_rsync_errors(
     auto_delete_log: bool,  # noqa: FBT001
 ) -> None:
     """Check rsync errors."""
-    with open(log_file) as f:
+    with open(log_file, encoding="utf-8", errors="replace") as f:
         log_data = f.read()
     if "rsync error:" in log_data:
         log_error(

tests/test_app.py

@@ -18,6 +18,7 @@
     backup,
     backup_marker_path,
     check_dest_is_backup_folder,
+    deal_with_no_space_left,
     expire_backups,
     find,
     find_backup_marker,
@@ -199,6 +200,82 @@ def test_find_backup_marker(tmp_path: Path) -> None:
     assert find_backup_marker(str(tmp_path), None) == marker_path
 
 
+def test_deal_with_no_space_left_handles_broken_pipe_when_dest_full(
+    tmp_path: Path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Broken pipe with a full destination should trigger expiration."""
+    log_file = tmp_path / "2025-10-12-212400.log"
+    log_file.write_text("rsync: [sender] write error: Broken pipe (32)\n", encoding="utf-8")
+
+    backups = [
+        "/dest/2025-10-11-120000",
+        "/dest/2025-10-12-120000",
+    ]
+
+    monkeypatch.setattr(rsync_time_machine, "find_backups", Mock(return_value=backups))
+
+    expired: list[str] = []
+    monkeypatch.setattr(
+        rsync_time_machine,
+        "expire_backup",
+        lambda path, ssh: expired.append(path),
+    )
+
+    def fake_run_cmd(cmd: str, ssh: rsync_time_machine.SSH | None = None) -> rsync_time_machine.CmdResult:
+        if cmd.startswith("df -Pk"):
+            df_output = (
+                "Filesystem 1024-blocks Used Available Capacity Mounted on\n"
+                "/dev/sda1 100 100 0 100% /dest\n"
+            )
+            return rsync_time_machine.CmdResult(df_output, "", 0)
+        return rsync_time_machine.CmdResult("", "", 0)
+
+    monkeypatch.setattr(rsync_time_machine, "run_cmd", fake_run_cmd)
+
+    should_retry = deal_with_no_space_left(
+        str(log_file),
+        "/dest",
+        ssh=None,
+        auto_expire=True,
+    )
+
+    assert should_retry is True
+    assert expired == [sorted(backups)[-1]]
+
+
+def test_deal_with_no_space_left_ignores_broken_pipe_when_space_available(
+    tmp_path: Path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Broken pipe without the destination filling up should not expire backups."""
+    log_file = tmp_path / "2025-10-12-212400.log"
+    log_file.write_text("rsync: [sender] write error: Broken pipe (32)\n", encoding="utf-8")
+
+    monkeypatch.setattr(rsync_time_machine, "find_backups", Mock(return_value=["/dest/2025-10-12-120000", "/dest/2025-10-11-120000"]))
+    monkeypatch.setattr(rsync_time_machine, "expire_backup", Mock())
+
+    def fake_run_cmd(cmd: str, ssh: rsync_time_machine.SSH | None = None) -> rsync_time_machine.CmdResult:
+        if cmd.startswith("df -Pk"):
+            df_output = (
+                "Filesystem 1024-blocks Used Available Capacity Mounted on\n"
+                "/dev/sda1 100 58 42 58% /dest\n"
+            )
+            return rsync_time_machine.CmdResult(df_output, "", 0)
+        return rsync_time_machine.CmdResult("", "", 0)
+
+    monkeypatch.setattr(rsync_time_machine, "run_cmd", fake_run_cmd)
+
+    should_retry = deal_with_no_space_left(
+        str(log_file),
+        "/dest",
+        ssh=None,
+        auto_expire=True,
+    )
+
+    assert should_retry is False
+
+
 def test_run_cmd() -> None:
     """Test the run_cmd function."""
     result = run_cmd("echo 'Hello, World!'")