Ext4 + barriers=1 + ssd + power loss while commiting to a git repo = broken repo?

[Jeff Moyer]

Ric Wheeler <rwheeler at redhat.com> writes:

> On 04/14/2011 05:19 AM, Andreas Schwab wrote:
>> Michał Piotrowski<mkkp4x4 at gmail.com>  writes:
>>
>>> W dniu 14 kwietnia 2011 11:04 użytkownik Andreas Schwab
>>> <schwab at redhat.com>  napisał:
>>>> Michał Piotrowski<mkkp4x4 at gmail.com>  writes:
>>>>
>>>>> But the question remains - should enabled barriers protect against
>>>>> such data loss/breakage? Or I just had a big bad luck?
>>>> It could also be a bug in git, perhaps it needs to take more care to
>>>> create the ref file atomically.
>>> Should I report it to upstream or in bugzilla.redhat.com?
>> Looking closer it seems like git already does the right thing
>> (open("master.lock"), write(sha1), rename("master.lock", "master")), so
>> it appears to be a barriers issue.
>
> If the files exist, but do not have newly written data, you will still need an 
> fsync() in there somewhere I think....

To be clear, Ric is being modest.  He knows you need an fsync, so you
should listen to him.  ;-)

Cheers,
Jeff