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Re: [Qemu-devel] [Qemu-block] [PATCH 0/2] block/file-posix: Reduce xfsct
From: |
Stefano Garzarella |
Subject: |
Re: [Qemu-devel] [Qemu-block] [PATCH 0/2] block/file-posix: Reduce xfsctl() use |
Date: |
Wed, 28 Aug 2019 11:34:41 +0200 |
User-agent: |
NeoMutt/20180716 |
On Fri, Aug 23, 2019 at 03:03:39PM +0200, Max Reitz wrote:
> Hi,
>
> As suggested by Paolo, this series drops xfsctl() calls where we have
> working fallocate() alternatives. (And thus replaces “block/file-posix:
> Fix xfs_write_zeroes()”.)
>
> Unfortunately, we also use xfsctl() to inquire the request alignment for
> O_DIRECT, and this is the only way we currently have to obtain it
> without trying. Therefore, I didn’t quite like removing that call, too,
> so this series doesn’t get rid of xfsctl() completely.
>
> (If we did, we could delete 146 lines instead of these measly 76 here.)
>
>
> Anyway, dropping xfs_write_zeroes() will also fix the guest corruptions
> Lukáš has reported (for qcow2, but I think it should be possible to see
> similar corruptions with raw, although I haven’t investigated that too
> far).
>
>
> Max Reitz (2):
> block/file-posix: Reduce xfsctl() use
> iotests: Test reverse sub-cluster qcow2 writes
>
> block/file-posix.c | 77 +-------------------------------------
> tests/qemu-iotests/265 | 67 +++++++++++++++++++++++++++++++++
> tests/qemu-iotests/265.out | 6 +++
> tests/qemu-iotests/group | 1 +
> 4 files changed, 75 insertions(+), 76 deletions(-)
> create mode 100755 tests/qemu-iotests/265
> create mode 100644 tests/qemu-iotests/265.out
The patch and the test LGTM.
I tried to run the 265 test without the
"block/file-posix: Reduce xfsctl() use" patch and the failure rate is ~30% on
my system.
With the patch applied the failure rate is 0% :-)
Reviewed-by: Stefano Garzarella <address@hidden>
Tested-by: Stefano Garzarella <address@hidden>
Thanks,
Stefano