On Mon, Sep 14, 2015 at 04:51:48PM +0200, Holger Hoffstätte wrote: > On 09/14/15 08:04, Omar Sandoval wrote: > > I went back and fixed the issues that came up since v2. Changes below. I > > removed Josef's Reviewed-by on patch 9 because it was completely > > rewritten to change the mount options like Dave suggested. These are > > still based on 4.2 > > I decided to take one for the team and try this. > > Merging it into my custom 4.1++ tree (with btrfs at ~4.3) worked flawlessly, > just as the -progs bits. \o/ > > Upgrading existing filesystems works fine and performance on my peasant > systems with SATA SSDs and rust is still good; not worse but also not > noticeably better. Maybe it is and I just didn't notice; otherwise I guess > that's good for a cache which is not really supposed to be noticeable. :) > > Unmounting, remounting, btrfs check all also seem to work as expected. > > Two questions: > > 1) I believe the previous postings mentioned that the fst inherits the > metadata properties - does this mean that e.g. on a single rotational > disk with data=single,metadata=dup the fst is also dup? Is this good, > bad, intentional? I guess it might prevent some of the problems with > corrupted v1 caches that some people had.
Yeah, that's correct, the free space tree will have the same profile as the rest of the metadata. There's certainly a cost in duplicating the free space tree where the old space cache wouldn't have been duplicated, but it's a good thing that the free space tree be consistent with the rest of the metadata. > 2) the following: > > > - Changed the free_space_tree option to space_cache=v2 and made clear_cache > > clear the free space tree. If the free space tree has been created, > > the mount will fail unless space_cache=v2 or nospace_cache,clear_cache > > is given because we cannot allow the free space tree to get out of > > date. > > also all seem to work in my testing (wrt. the clearing/downgrading to v1), > but once a volume has been upgraded to v2 fst, a simple mount does not need > to specify space_cache=v2 again; it seems to stick until cleared/downgraded. > Not sure if that is what you meant to say. Yeah, to be clear: if the filesystem is mounted with space_cache=v2 once, it's assumed from then on unless the user specifies otherwise (i.e., nospace_cache,clear_cache). The idea there was to be consistent with the original space_cache. > Long story short: +1 excellent job and: > Tested-by: Holger Hoffstätte <holger.hoffstae...@googlemail.com> > > cheers! > > Holger Thanks a ton for testing this out! -- Omar -- 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
