On Tuesday, May 18, 2010, Chris Mason wrote: > On Tue, May 18, 2010 at 05:57:49PM +0200, Jakob Unterwurzacher wrote: > > On 18/05/10 16:36, Chris Mason wrote: [...] > > > > I thought the problem of delaying the renames was complexity, well, at > > least T'Tso said it was [1] - I'm not sure if this applies to btrfs as well. > > I'm afraid there are lots and lots of different issues at play. The > most important way to look at it is that forcing data to disk is very > slow, which is why we try to avoid it whenever we can. > > Applications can request that the data go to disk via lots of different > ways. Rename was never ever meant to be one of them, but it really does > make sense to provide atomic replacement of old good data with new good > data, so we've implemented that extra syncing. > > Implementing syncing when userland doesn't expect extra syncing usually > just make userland very unhappy. It's not that we can't do it it's that > doing it has implications for every application that uses rename. > > -chris
Funny, the first thing that comes to my mind reading this thread, is that this kind of complaint is raised about a file-system which is able to support a full rollback via the snapshot. I think that a "right" solution should be to integrate the package manager with the btrfs snapshot capability (as nexenta does [1]). But it is clear that this is a long term solution (IIRC Fedora is working on this). In the mean time, which should be the "right" solution to solve the dpkg problem ( and in a more general form the package manager problem) with btrfs ? > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > [1] http://www.nexenta.org/os/TransactionalZFSUpgrades -- gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo) <kreijackATinwind.it> Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
