Am Freitag, 25. Juli 2014, 11:54:37 schrieb Martin Steigerwald:
> Am Donnerstag, 24. Juli 2014, 22:48:05 schrieben Sie:
> > When failing to allocate space for the whole compressed extent, we'll
> > fallback to uncompressed IO, but we've forgotten to redirty the pages
> > which belong to this compressed extent, and these 'clean' pages will
> > simply skip 'submit' part and go to endio directly, at last we got data
> > corruption as we write nothing.
> >
> > Signed-off-by: Liu Bo <bo.li....@oracle.com>
> > ---
> >
> > fs/btrfs/inode.c | 12 ++++++++++++
> > 1 file changed, 12 insertions(+)
> >
> > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> > index 3668048..8ea7610 100644
> > --- a/fs/btrfs/inode.c
> > +++ b/fs/btrfs/inode.c
> >
> > @@ -709,6 +709,18 @@ retry:
> > unlock_extent(io_tree, async_extent->start,
> >
> > async_extent->start +
> > async_extent->ram_size - 1);
> >
> > +
> > + /*
> > + * we need to redirty the pages if we decide to
> > + * fallback to uncompressed IO, otherwise we
> > + * will not submit these pages down to lower
> > + * layers.
> > + */
> > + extent_range_redirty_for_io(inode,
> > + async_extent->start,
> > + async_extent->start +
> > + async_extent->ram_size - 1);
> > +
> >
> > goto retry;
> >
> > }
> > goto out_free;
>
> I am testing this currently. So far no lockup. Lets see. Still has not
> filled the the block device with trees completely after I balanced them:
>
> Label: 'home' uuid: […]
> Total devices 2 FS bytes used 125.57GiB
> devid 1 size 160.00GiB used 153.00GiB path /dev/dm-0
> devid 2 size 160.00GiB used 153.00GiB path /dev/mapper/sata-home
>
> I believe the lockups happen more easily if the trees occupy all of disk
> space. Well I will do some compiling of some KDE components which may let
> BTRFS fill all space again.
>
> This patch will mean it when it can´t make enough free space in the
> (fragmented) tree it will write uncompressed?
>
> This would mean that one would have a defragment trees regularily to allow
> for writes to happen compressed at all times.
>
> Well… of course still better than lockup or corruption.
So lookups so far anymore.
Tested with 3.16-rc5, 3.16-rc7, now running 3-16 final.
/home BTRFS only got today filled completely tree-wise:
merkaba:~> btrfs fi sh /home
Label: 'home' uuid: […]
Total devices 2 FS bytes used 127.35GiB
devid 1 size 160.00GiB used 160.00GiB path /dev/mapper/msata-home
devid 2 size 160.00GiB used 160.00GiB path /dev/dm-3
But I had KDE and kernel compile running full throttle at that time and still
good.
Tested-By: Martin Steigerwald <mar...@lichtvoll.de>
I think this should go to stable. Thanks, Liu.
Ciao,
--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7
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