From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josef Bacik Subject: [PATCH 0/3] Btrfs: save free space cache to the disk V2 Date: Wed, 22 Sep 2010 14:39:39 -0400 Message-ID: <1285180782-29364-1-git-send-email-josef@redhat.com> To: linux-btrfs@vger.kernel.org Return-path: List-ID: V1->V2 - This includes my previous fix for the Incompat flags that I posted earlier - Fix kunmap() to use the page and not the vaddr, I messed this up when going from kmap_atomic to kmap 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. You can pull these patches from my git tree git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work.git and they should pull right onto Chris's btrfs-unstable tree. Please test this as it's a big change and I can only test so much. That being said this has been run through xfstests thoroughly and I've been running it on a VM with btrfs as root. Thanks, Josef