From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josef Bacik Subject: Re: [PATCH] Btrfs: fix oops while writing data to SSD partitions Date: Wed, 27 Jul 2011 10:26:12 -0400 Message-ID: <4E302004.2030007@redhat.com> References: <4E2FDF1E.8080206@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Linux Btrfs To: liubo Return-path: In-Reply-To: <4E2FDF1E.8080206@cn.fujitsu.com> List-ID: 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 Thanks, Josef