From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:59534 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754612AbaCKDAP (ORCPT ); Mon, 10 Mar 2014 23:00:15 -0400 Message-ID: <1394505491.6207.4.camel@localhost.localdomain> Subject: Re: Building a brtfs filesystem < 70M? From: Gui Hecheng To: Saul Wold Cc: "linux-btrfs@vger.kernel.org" Date: Tue, 11 Mar 2014 10:38:11 +0800 In-Reply-To: <531E4A02.5010404@linux.intel.com> References: <531E4A02.5010404@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, 2014-03-10 at 16:25 -0700, Saul Wold wrote: > Hi There > > There seems to be an issue if we try to build a btrfs based FS that is > less than 70M, we get the following assertion failure: > > mkfs.btrfs: extent-tree.c:2682: btrfs_reserve_extent: Assertion `!(ret)' > failed. > > I tried to do a search on this and did not find anything obvious. > > Further, if I do build a 70M image, it will not mount until I get to I > increase the about 100M! > > # mount -o loop -v rootfs.btrfs mnt > mount: wrong fs type, bad option, bad superblock on /dev/loop0, > missing codepage or helper program, or other error > > In some cases useful info is found in syslog - try > dmesg | tail or so. > > I can provide a small rootfs (~4M) example if needed > > Builds and mounts correct: > mkfs.btrfs -b 104857600 -r rootfs rootfs.btrfs > > Builds, but does not mount: > mkfs.btrfs -b 73400320 -r rootfs rootfs.btrfs > > Does not build, gives the above assertion error: > mkfs.btrfs -b 10889216 -r rootfs rootfs.btrfs > > > Thanks > Hi Saul, Sorry, I'm not able to reproduce your problem... Are you running the latest btrfs-progs from david's branch? Thanks, Gui