The fsck_snapshot lifecycle step exists to repair stale bitmaps in
a COW file reused from a prior aborted start — without it, the
later e2cp/e2rm calls in patch_root_overlay refuse to touch the
snapshot. On a freshly-created COW there are no stale bitmaps to
repair, so e2fsck -fy is pure overhead.
system_overlay already tracks whether it created the file this run
(sc.systemOverlayCreated, used to drive the rollback path). Reuse
that flag to skip e2fsck entirely on the create-fresh path. The
reused-COW path keeps the fsck for safety. Saves a few hundred ms
per VM create — small absolute win on top of the lazy-mkfs change,
but free.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Thales Maciel
b8c48765fb