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Subject: Re: JFFS2 powerfail ?
From: Artem Bityutskiy <dedekind@infradead.org>
To: Jamie Lokier <jamie@shareable.org>
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Date: Wed, 23 Apr 2008 20:52:58 +0300
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On Wed, 2008-04-23 at 18:48 +0100, Jamie Lokier wrote:
> Artem Bityutskiy wrote:
> > > JFFS2 notice: (791) check_node_data: wrong data CRC in data node at 0=
x01062120: read 0xfac2f85a, calculated 0x9ac0c6d1.
> > > JFFS2 notice: (791) check_node_data: wrong data CRC in data node at 0=
x002b9bf0: read 0x9f182fab, calculated 0x4ad20e5f.
> > > JFFS2 notice: (791) check_node_data: wrong data CRC in data node at 0=
x002b5d60: read 0x79a2a9d8, calculated 0x35234c9a.
> >=20
> > This is normal. It's just half-written nodes which correspond to the
> > last writes you made before the power cut. They are harmless, although
> > spam the syslog. JFFS2 cannot remove them straight after mount, so they
> > may accumulate. Which means each time you see corruption messages for
> > the previous unclean reboots. However, the corrupted nodes will go away
> > some time, when JFFS2 decides to garbage-collect corresponding
> > eraseblocks. IOW, don't worry, this is a feature.
>=20
> If they are going to be removed at the next GC, it would be nice to
> remove them earlier by overwriting them with all-1s - would that work?
>=20

Yes, it is not a big problem to remember such blocks on scan and then
garbage collect them. Its just nobody cared enough to implement this.
You could try :-)

--=20
Best regards,
Artem Bityutskiy (=D0=91=D0=B8=D1=82=D1=8E=D1=86=D0=BA=D0=B8=D0=B9 =D0=90=
=D1=80=D1=82=D1=91=D0=BC)