[dm-devel] hunt for 2.6.37 dm-crypt+ext4 corruption? (was: Re: dm-crypt barrier support is effective)

[Jon Nelson]

I finally found some time to test this out. With 2.6.37-rc4 (openSUSE
KOTD kernel) I easily encounter the issue.

Using a virtual machine, I created a stock, minimal openSUSE 11.3 x86_64
install, installed all updates, installed postgresql and the 'KOTD'
(Kernel of the Day)
kernel, and ran the following tests (as postgres user because I'm
lazy).

1. create a database (from bash):

createdb test

2. place the following contents in a file (I used 't.sql'):

begin;
create temporary table foo as select x as a, ARRAY[x] as b FROM
generate_series(1, 10000000 ) AS x;
create index foo_a_idx on foo (a);
create index foo_b_idx on foo USING GIN (b);
rollback;

3. execute that sql:

psql -f t.sql --echo-all test


With 2.6.34.7 I can re-run [3] all day long, as many times as I want,
without issue.

With 2.6.37-rc4-13 (the currently-installed KOTD kernel) if tails
pretty frequently.

Then I tested with the 'vanilla' kernel available here:

http://download.opensuse.org/repositories/Kernel:/vanilla/standard/

The 'vanilla' kernel exhibited the same problems.
The version I tested:  2.6.37-rc4-219-g771f8bc-vanilla.

Incidentally, quick tests of jfs, xfs, and ext3 do _not_ show the same
problems, although I will note that I usually saw failure at least 1
in 3, but sometimes had to re-run the sql test 4 or 5 times before I
saw failure.

I will continue to do some testing, but I will hold off on testing the
commits above until I receive further testing suggestions.

-- 
Jon