From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sander Subject: Re: [PATCH 0/3] Btrfs: save free space cache to the disk Date: Mon, 20 Sep 2010 13:24:46 +0200 Message-ID: <20100920112446.GA10866@attic.humilis.net> References: <1284577734-3161-1-git-send-email-josef@redhat.com> Reply-To: sander@humilis.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-btrfs@vger.kernel.org To: Josef Bacik Return-path: In-Reply-To: <1284577734-3161-1-git-send-email-josef@redhat.com> List-ID: Josef Bacik wrote (ao): > This patch series introduces the ability for btrfs to store the free space cache > ondisk to make the caching of a block group much quicker. Previously we had to > search the entire extent-tree to look for gaps everytime we wanted to allocate > in a block group. This approach instead dumps all of the free space cache to > disk for every dirtied block group each time we commit the transaction. This is > a disk format change, but in order to use the feature you will have to mount > with -o space_cache, and then from then on you won't be able to use old kernels > with your filesystem. Will this go into a future version of btrfs? If so, would it make sense to include other changes that would require a format change? Sander -- Humilis IT Services and Solutions http://www.humilis.net