From mboxrd@z Thu Jan 1 00:00:00 1970 From: liubo Subject: Re: [PATCH] Btrfs: fix oops while writing data to SSD partitions Date: Thu, 28 Jul 2011 09:11:56 +0800 Message-ID: <4E30B75C.3070509@cn.fujitsu.com> References: <4E2FDF1E.8080206@cn.fujitsu.com> <4E302004.2030007@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Linux Btrfs To: Josef Bacik Return-path: In-Reply-To: <4E302004.2030007@redhat.com> List-ID: On 07/27/2011 10:26 PM, Josef Bacik wrote: > On 07/27/2011 05:49 AM, liubo wrote: >> Here I have a two SSD-partitions btrfs, and they are defaultly set to >> "data=raid0, metadata=raid1", then I try to fill my btrfs partition >> till "No space left on device", via "dd if=/dev/zero of=/mnt/btrfs/tmp". >> >> I get an oops panic from kernel BUG at fs/btrfs/extent-tree.c:5199!, which >> refers to find_free_extent's >> BUG_ON(index != get_block_group_index(block_group)); >> >> In SSD mode, in order to find enough space to alloc, we may check the >> block_group cache which has been checked sometime before, but the index is not >> updated, where it hits the BUG_ON. >> >> Signed-off-by: Liu Bo >> --- >> fs/btrfs/extent-tree.c | 4 +++- >> 1 files changed, 3 insertions(+), 1 deletions(-) >> >> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c >> index 71cd456..3213c39 100644 >> --- a/fs/btrfs/extent-tree.c >> +++ b/fs/btrfs/extent-tree.c >> @@ -5065,7 +5065,9 @@ have_block_group: >> * group is does point to and try again >> */ >> if (!last_ptr_loop && last_ptr->block_group && >> - last_ptr->block_group != block_group) { >> + last_ptr->block_group != block_group && >> + index <= >> + get_block_group_index(last_ptr->block_group)) { >> >> btrfs_put_block_group(block_group); >> block_group = last_ptr->block_group; > > Ugh I wish we could make this prettier but > > Acked-by: Josef Bacik > I wish that, too. ;) But lots of goto really make life harder...we can somehow improve it later. thanks, liubo > Thanks, > > Josef >