agent v0.36.3: DetachDrive loop-umounts stacked binds (full detach)

Detach now removes ALL stacked binds at a stable path, not just one layer, so an
eject fully detaches even with >1 bind (keeping fail-close intact).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -3,6 +3,12 @@
 All notable changes to **felhom-agent** are recorded here. Update on every code
 change that gets pushed.
 
+## v0.36.3 — DetachDrive loop-umounts stacked binds (2026-06-15)
+
+DetachDrive now umounts ALL stacked binds at a stable path (bounded loop), not just one layer — so an
+eject/detach fully detaches even if more than one bind accumulated (operator bind on top, or a rare
+attach race), keeping the fail-close intact. Caught in the E13 rapid eject/reconnect sweep.
+
 ## v0.36.2 — eject also keeps the raw mounted (reconnectable) (2026-06-15)
 
 Extends v0.36.1 to EJECT: eject now DetachDrive`s the bind under the parent but LEAVES the raw

cmd/felhom-agent/main.go

@@ -44,7 +44,7 @@ import (
 
 // version is the agent version. Overridable at build time with
 // -ldflags "-X main.version=<v>"; defaults to the in-repo CHANGELOG version.
-var version = "0.36.2"
+var version = "0.36.3"
 
 // runGuestHook is the PVE pre-start hook body (`felhom-agent guest-hook <vmid> <phase>`). On the
 // pre-start phase it creates placeholder dirs for any absent bind-mount source so the guest always boots

internal/localapi/intermediary.go

@@ -293,13 +293,18 @@ func (b *GuestBinder) DetachDrive(ctx context.Context, where string) error {
 	if stable == "" {
 		return fmt.Errorf("guest-detach: %q is not a /mnt/<name> mount", where)
 	}
-	if !isHostMountpoint(stable) {
-		return nil // already detached
+	// Loop-umount: a stable path can carry MORE THAN ONE stacked bind (e.g. an operator-applied bind on
+	// top of the agent's, or a rare attach race). Detach must remove ALL layers, else eject leaves a
+	// lower bind exposing data → fail-close broken. Bounded to avoid an infinite loop.
+	for i := 0; i < 16 && isHostMountpoint(stable); i++ {
+		if err := b.run(ctx, "umount", stable); err != nil {
+			return fmt.Errorf("guest-detach: umount %s (layer %d): %w", stable, i, err)
+		}
 	}
-	if err := b.run(ctx, "umount", stable); err != nil {
-		return fmt.Errorf("guest-detach: umount %s: %w", stable, err)
+	if isHostMountpoint(stable) {
+		return fmt.Errorf("guest-detach: %s still a mountpoint after 16 umounts", stable)
 	}
-	b.logger.Info("guest-detach: drive unmounted from shared parent (live, fail-closed)", "where", where, "stable", stable)
+	b.logger.Info("guest-detach: drive fully unmounted from shared parent (live, fail-closed)", "where", where, "stable", stable)
 	return nil
 }