- Add retry with backoff to dmsetupRemove for transient "device busy"
errors caused by kernel not releasing the device immediately after
Firecracker exits. Only retries on "Device or resource busy"; other
errors (not found, permission denied) return immediately.
- Thread context.Context through RemoveSnapshot/RestoreSnapshot so
retries respect cancellation. Use context.Background() in all error
cleanup paths to prevent cancelled contexts from skipping cleanup
and leaking dm devices on the host.
- Resume vCPUs on pause failure: if snapshot creation or memfile
processing fails after freezing the VM, unfreeze vCPUs so the
sandbox stays usable instead of becoming a frozen zombie.
- Fix resource leaks in Pause when CoW rename or metadata write fails:
properly clean up network, slot, loop device, and remove from boxes
map instead of leaving a dead sandbox with leaked host resources.
- Fix Resume WaitUntilReady failure: roll back CoW file to the snapshot
directory instead of deleting it, preserving the paused state so the
user can retry.
- Skip m.loops.Release when RemoveSnapshot fails during pause since
the stale dm device still references the origin loop device.
- Fix incorrect VCPUs placeholder in Resume VMConfig that used memory
size instead of a sensible default.
pptx704
88246fac2b