When running the integrity test ('integck' from mtd-utils) on current
UBIFS on 2.6.35, I see that assertions in UBIFS 'list_sort()' comparison
functions trigger sometimes, e.g.:
UBIFS assert failed in data_nodes_cmp at 132 (pid 28311)
My investigation showed that this happens when 'list_sort()' calls the 'cmp()'
function with equivalent arguments. In this case, the 'struct list_head'
parameter, passed to 'cmp()' is bogus, and it does not belong to any element in
the original list.
And this issue seems to be introduced by commit:
commit 835cc0c847
Author: Don Mullis <don.mullis@gmail.com>
Date: Fri Mar 5 13:43:15 2010 -0800
It is easy to work around the issue by doing:
if (a == b)
return 0;
in UBIFS. It works, but 'lib_sort()' should nevertheless be fixed. Although it
is harmless to have this piece of code in UBIFS.
This patch adds that code to both UBIFS 'cmp()' functions:
'data_nodes_cmp()' and 'nondata_nodes_cmp()'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
1a9476a770