On Tue, Dec 7, 2010 at 12:52 PM, Chris Mason <chris.mason@xxxxxxxxxx> wrote: > Excerpts from Jon Nelson's message of 2010-12-07 13:45:14 -0500: >> On Tue, Dec 7, 2010 at 12:22 PM, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: >> > On Tue, Dec 07 2010 at Â1:10pm -0500, >> > Jon Nelson <jnelson@xxxxxxxxxxx> wrote: >> > >> >> 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. >> > >> > How does it fail? Âpostgres errors? Âkernel 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. > > This sounds a lot like a bug higher up than dm-crypt. ÂZeros 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. -- Jon -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
