Possible race in device mapper

[Neil Brown]

On Wednesday October 5, jdizzl at xs4all.nl wrote:
> Hi all,
> 
> I'm mailing this directly as I'd like an opinion of you guys on whether my 
> hunch could be correct:
> 
> I've filed a kernel bug report early this year and have been gathering more 
> and more info on it ever since. (Bug #295657.) In the beginning it seemed an 
> EXT3 bug on RAID, that messed up the filesystem. Later I suspected that it 
> might be a problem with 4K stacks, but last week I've come to the conclusion 
> that there might be some sort of race condition in the dm crypto-layer that 
> messes up when decrypting. It's especially easily triggered during heavy 
> disk-io.
> 
> I'm running 2.6.11-1-686-smp on a dual P2-400 with 2 raidsets. See the bug 
> report for more info: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=295657
> 
> Since I removed the crypto-layer from the filesystem I have no more filesystem 
> inconsistencies.
> 
> Could you please shed your light on this matter to see whether I should file a 
> formal dm-bug? Thanks.
> 
> Cheers,
> Jeroen van Disseldorp
> 
> PS. Neil: Although you're not lister as maintainer, I got a tip from Wichert 
> Akkerman that you might be able to help in this.

Does that kernel contain this patch (2.6.11 didn't): ??

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blobdiff;h=249dd6bb66c843ee9e487f124dbe37afab095581;hp=ca8f7a850fe30aa27cb6e3b524464197bd76f3c8;hb=a5453be48e8def75a9c1b2177b82fa0e692c6e3a;f=fs/bio.c

--- fs/bio.c
+++ fs/bio.c
@@ -261,6 +261,7 @@ inline void __bio_clone(struct bio *bio,
	 */
	bio->bi_vcnt = bio_src->bi_vcnt;
 	bio->bi_size = bio_src->bi_size;
+	bio->bi_idx = bio_src->bi_idx;
	bio_phys_segments(q, bio);
	bio_hw_segments(q, bio);
	}

If not, could you try a kernel that does and let me know if it still
fails?

NeilBrown