From: Jon Nelson Subject: Re: hunt for 2.6.37 dm-crypt+ext4 corruption? (was: Re: dm-crypt barrier support is effective) Date: Tue, 7 Dec 2010 12:45:14 -0600 Message-ID: References: <4CF692D1.1010906@redhat.com> <4CF6B3E8.2000406@redhat.com> <20101201212310.GA15648@redhat.com> <20101204193828.GB13871@redhat.com> <20101207142145.GA27861@think> <20101207182243.GB21112@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Chris Mason , Matt , Milan Broz , Andi Kleen , linux-btrfs , dm-devel , Linux Kernel , htd , htejun@gmail.com, linux-ext4@vger.kernel.org To: Mike Snitzer Return-path: In-Reply-To: <20101207182243.GB21112@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Tue, Dec 7, 2010 at 12:22 PM, Mike Snitzer wrot= e: > On Tue, Dec 07 2010 at =C2=A01:10pm -0500, > Jon Nelson wrote: > >> I finally found some time to test this out. With 2.6.37-rc4 (openSUS= E >> KOTD kernel) I easily encounter the issue. >> >> Using a virtual machine, I created a stock, minimal openSUSE 11.3 x8= 6_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. > > How does it fail? =C2=A0postgres errors? =C2=A0kernel errors? postgresql errors. Typically, header corruption but from the limited visibility I've had into this via strace, what I see is zeroed pages where there shouldn't be. I just ran a test and got: ERROR: invalid page header in block 37483 of relation base/16384/16417 but that is not the only error one might get. >> 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: =C2=A02.6.37-rc4-219-g771f8bc-vanilla. >> >> Incidentally, quick tests of jfs, xfs, and ext3 do _not_ show the sa= me >> 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 t= he >> commits above until I receive further testing suggestions. > > OK, so to be clear: your testing is on dm-crypt + ext4? Yes. I took a virtual hard disk which shows up as /dev/sdb, used cryptsetup to format it as a LUKS volume, mounted the LUKS volume, formatted as ext4 (or whatever), mounted that, rsync'd over a blank postgresql 'data' directory, started postgresql, became the postgres user, and proceeded to create the db and run the sql. > And you're testing upstream based kernels (meaning the dm-crypt > scalability patch that has been in question is _not_ in the mix)? I am testing both the KOTD kernels and the "vanilla" kernels - neither of which has the dm-crypt patches (as far as I know). --=20 Jon