lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <1291754340-sup-1631@think> Date: Tue, 07 Dec 2010 15:41:50 -0500 From: Chris Mason <chris.mason@...cle.com> To: Jon Nelson <jnelson@...poni.net> Cc: Mike Snitzer <snitzer@...hat.com>, Matt <jackdachef@...il.com>, Milan Broz <mbroz@...hat.com>, Andi Kleen <andi@...stfloor.org>, linux-btrfs <linux-btrfs@...r.kernel.org>, dm-devel <dm-devel@...hat.com>, Linux Kernel <linux-kernel@...r.kernel.org>, htd <htd@...cy-poultry.org>, htejun <htejun@...il.com>, linux-ext4 <linux-ext4@...r.kernel.org> Subject: Re: hunt for 2.6.37 dm-crypt+ext4 corruption? (was: Re: dm-crypt barrier support is effective) Excerpts from Jon Nelson's message of 2010-12-07 15:25:47 -0500: > On Tue, Dec 7, 2010 at 2:02 PM, Chris Mason <chris.mason@...cle.com> wrote: > > Excerpts from Jon Nelson's message of 2010-12-07 14:34:40 -0500: > >> On Tue, Dec 7, 2010 at 12:52 PM, Chris Mason <chris.mason@...cle.com> wrote: > >> >> 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. > >> > > >> > This sounds a lot like a bug higher up than dm-crypt. Zeros tend to > >> > come from some piece of code explicitly filling a page with zeros, and > >> > that often happens in the corner cases for O_DIRECT and a few other > >> > places in the filesystem. > >> > > >> > Have you tried triggering this with a regular block device? > >> > >> I just tried the whole set of tests, but with /dev/sdb directly (as > >> ext4) without any crypt-y bits. > >> It takes more iterations but out of 6 tests I had one failure: same > >> type of thing, 'invalid page header in block ....'. > >> > >> I can't guarantee that it is a full-page of zeroes, just what I saw > >> from the (limited) stracing I did. > > > > Fantastic. Now for our usual suspects: > > > > 1) Is postgres using O_DIRECT? If yes, please turn it off > > According to strace, O_DIRECT didn't show up once during the test. > > > 2) Is postgres allocating sparse files? If yes, please have it fully > > allocate the file instead. > > That's a tough one. I don't think postgresql does that, but I'm not an > expert here. Ok, please compare du -k and du -k --apparent-size for each of the files involved in the postgres run. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists