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:
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
Also, Eric, can you run this proof-of-concept test branch (on top of
the current XFS for-2.6.36 branch) and see if QEMU is happy with it?
It passes this test on my machine....
The following changes since commit d2ec2c790b3994bf0c4381cacc489b514705887c:
xfs: clean up xfs_bmap_get_bp (2010-07-22 12:52:08 +1000)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/xfsdev aio-unaligned
Dave Chinner (4):
Merge branch 'master' into working
Merge branch 'for-2.6.36' into working
fs: get_blocks needs an unaligned mapping flag
xfs: serialise unaligned direct IO into unwritten extents
fs/buffer.c | 17 ++++++++-------
fs/direct-io.c | 25 ++++++++++++++++++++--
fs/ioctl.c | 2 +-
fs/mpage.c | 6 +++-
fs/xfs/linux-2.6/xfs_aops.c | 47 +++++++++++++++++++++++++++++++++---------
include/linux/fs.h | 10 ++++++++-
6 files changed, 82 insertions(+), 25 deletions(-)
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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