On Thu, Jul 22, 2010 at 10:32:29PM -0500, Eric Sandeen wrote: > Dave Chinner wrote: > > > On Thu, Jul 22, 2010 at 02:05:26PM -0500, Eric Sandeen wrote: > > > >> This replicates file corruption we've seen with qemu-kvm when > >> we use if=virtio,cache=none,aio=native for IO to a sparse > >> ext4- or xfs-hosted file, and the partitions/filesystems > >> within that file image are not block-aligned. (think sector > >> 63 here...) This results in AIO IOs not aligned to the > >> filesystem blocks. > >> > >> This test modifies aiodio_sparse2.c to add an option to start > >> the file IO at an offset. > >> > >> When we do 4k writes to a 16k file in 2 threads, starting > >> at offset 512, we get 0s interspersed in the file where they > >> should not be: > >> > >> 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > >> * > >> 00000200 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 |................| > >> * > >> 00001000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > >> * > >> 00001200 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 |................| > >> .... > >> > >> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxxx> > >> > > > > looks good - it needs to remove the $TEST_DIR/aiodio_sparse file > > before the test starts, though, so that repeated tests fail > > correctly. Otherwise: > > > > > hm, but: > > +rm -f "$TEST_DIR/aiodio_sparse*" > + > +# 2 threads, 4k writes, 16k filesize, stride throug file by 4k, start at 512 offset > +$here/src/aio-dio-regress/aiodio_sparse2 -i 2 -w 4k -s 16k -n 4k -o 512 "$TEST_DIR/aiodio_sparse" > > It does remove it ... no? Sorry, my bad - that went in one eye and out the other when I read through the whole patch. When i was testing I was getting a repeatable fail - pass - fail - pass ... pattern occurring without any kernel patches applied, and the test warns about removing the file after failure, so I just connected the dots up in the obvious manner and got it completely wrong.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
