On Wed, Jan 17, 2018 at 2:07 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> The original git design was very much to write each object file
> without any syncing, because they don't matter since a new object file
> - by definition - isn't really reachable. Then sync before writing the
> index file or a new ref.
.. actually, I think it originally sync'ed only before starting to
actually remove objects due to repacking.
The theory was that you can lose the last commit series or whatever,
and have to git-fsck, and have to re-do it, but you could never lose
long-term work. If your machine crashes, you still remember what you
did just before the crash.
That theory may have been more correct back in the days than it is
now. People who use git might be less willing to treat it like a
filesystem that you can fsck than I was back 10+ ago.
It's worth noting that the commit that Junio pointed to (from 2008)
didn't actually change any behavior. It just allowed people who cared
to change behavior. The original "let's not waste time on fsync every
object write, because we can just re-create the state anyway" behavior
goes back to 2005.
Linus
