Re: [PATCH] refs: sync loose refs to disk before committing them

On Fri, Nov 05, 2021 at 09:35:24AM +0100, Ævar Arnfjörð Bjarmason wrote:

So if we're in the middle of a transaction and have created and written
the lockfile we might only notice that the disk has is full when we do
the fsync().

In that case we'll (or should, I didn't check just now) unroll the ref
transaction, and delete the *.lock files we created, which presumably
will succeed in that scenario.

So calling die() at this level is the difference between leaving the
repo in an inconsistent state due to a disk error, and something like
"git fetch --atomic" gracefully failing.

We should rollback the lockfiles even if we call die(), via the atexit()
handler. Ditto if we receive a fatal signal.

(But I completely agree that if we have the opportunity to just pass the
error up the stack, we should do so).

-Peff