[pacman-dev] [PATCH] Sync data after writing to the local db

[Dan McGee]

On Sat, Oct 30, 2010 at 6:01 PM, Allan McRae <allan at archlinux.org> wrote:
> On 30/10/10 23:40, Xavier Chantry wrote:
>>
>> On Sat, Oct 30, 2010 at 3:01 PM, Nagy Gabor<ngaba at bibl.u-szeged.hu>
>>  wrote:
>>>
>>> Wouldn't this cause a notable slow-down?
>>>
>>
>> I thought the issue was rather that the local db entries would be
>> synced when the actual package files are probably not synced.
>> But if we sync everything, then it's very likely to become very slow.
>
> This is to fix issues like:
> error: could not open file
> /var/lib/pacman/local/texlive-bin-2010.1-4/depends: No such file or
> directory
>
> Missing package files can be detected using -Qk and fixed by reinstall so I
> find it reasonable to just sync the local db entries.  Also, doing just that
> should not slow down the sync operation too much.
>
>> I seem to remember that Dan sent a fdatasync patch a while ago, I
>> don't remember if it affected only the db or both db and files.
>>
>> Also let's not forget this :
>>        Calling fsync() does not necessarily ensure that the entry in
>> the directory
>>        containing the file has also reached disk.  For that an
>> explicit fsync() on a
>>        file descriptor for the directory is also needed.
>>
>
> That would probably be better.  I only did the files because the file
> descriptor for those was handy...

I have a bunch of local work that does all thsi right, so for now I'm
going to toss this patch and I'll let you guys comment on my work once
I get it posted here.

-Dan