On Mon, Oct 8, 2012 at 8:19 AM, Chris Mason <chris.ma...@fusionio.com> wrote: > On Mon, Oct 08, 2012 at 06:18:26AM -0600, Liu Bo wrote: >> On 10/03/2012 10:02 PM, Chris Mason wrote: >> > On Tue, Sep 25, 2012 at 07:07:53PM -0600, Liu Bo wrote: >> >> On 09/26/2012 01:39 AM, Mitch Harder wrote: >> >>> On Mon, Sep 17, 2012 at 4:58 AM, Liu Bo <bo.li....@oracle.com> wrote: >> >>>> This comes from one of btrfs's project ideas, >> >>>> As we defragment files, we break any sharing from other snapshots. >> >>>> The balancing code will preserve the sharing, and defrag needs to grow >> >>>> this >> >>>> as well. >> >>>> >> >>>> Now we're able to fill the blank with this patch, in which we make full >> >>>> use of >> >>>> backref walking stuff. >> >>>> >> >>>> Here is the basic idea, >> >>>> o set the writeback ranges started by defragment with flag >> >>>> EXTENT_DEFRAG >> >>>> o at endio, after we finish updating fs tree, we use backref walking >> >>>> to find >> >>>> all parents of the ranges and re-link them with the new COWed file >> >>>> layout by >> >>>> adding corresponding backrefs. >> >>>> >> >>>> Originally patch by Li Zefan <l...@cn.fujitsu.com> >> >>>> Signed-off-by: Liu Bo <bo.li....@oracle.com> >> >>> >> >>> I'm hitting the WARN_ON in record_extent_backrefs() indicating a >> >>> problem with the return value from iterate_inodes_from_logical(). >> > >> > Me too. It triggers reliably with mount -o autodefrag, and then crashes >> > a in the next function ;) >> > >> > -chris >> > >> >> Hi Chris, Mitch, >> >> I'm afraid that I may need a little more time to fix all bugs in it because >> there seems to be >> some backref walking bugs mixed in, and at least 4 different crashes make it >> harder to address bugs. >> >> I use an 1G random write fio job running in background, following by >> creating 20 snapshots in background, >> and mount -o autodefrag. >> >> So if your crash is quite stable in one place, please let me know the steps. > > I have a notmuch mail database. I just receive mail with auto defrag on > and it crashes. Chrome databases may do it as well. > > If it helps, I have compression too. > > -chris >
I can usually reproduce fairly quickly, but I don't have a test that fails in exactly the same spot every time. My tests usually involve manipulating kernel git sources with autodefrag (and usually lzo compression). I have also hit a similar error when balancing a partition with multiple snapshots. I'll go back and review my methods for replicating, and see if any of them can reproduce predictably. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
