[PATCH 5/7] UBIFS: do not look up junk nodes

Artem Bityutskiy dedekind1 at gmail.com
Sat Aug 7 08:45:01 EDT 2010

Adrian, thanks for review!

On Sat, 2010-08-07 at 15:06 +0300, Adrian Hunter wrote:
> Artem Bityutskiy wrote:
> > From: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
> > 
> > When moving nodes, do not try to look up truncation and padding nodes in TNC,
> > because they do not exist there. This bug was most probably harmless, because
> > the TNC look-up probably failed for all padding and truncation nodes, but it
> The scan does not return padding nodes.

Oh yes.

> > could also succeed and lead to various "interesting" errors.
> Why would it succeed?

In 'ubifs_add_snod()' we call call 'key_read(c, &ino->key, &snod->key)'
for truncation nodes. However, 'struct ubifs_trun_node' does not have
key, so we read something else, and may happen to succeed in TNC lookup

I guess the 'ubifs_add_snod()' should be fixed. Then key for truncation
nodes will be zero, and TNC lookup wont's succeed for sure, but it is
safer still to avoid look up for anything but data/ino/dent/xent nodes,
I think, no?

Best Regards,
Artem Bityutskiy (Артём Битюцкий)

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