[Qemu-devel] [PATCH 0/2] block/file-posix: Reduce xfsctl() use

From: Max Reitz <mreitz@redhat.com>
To: qemu-block@nongnu.org
Cc: "Lukáš Doktor" <ldoktor@redhat.com>,
	"Kevin Wolf" <kwolf@redhat.com>,
	qemu-stable@nongnu.org, qemu-devel@nongnu.org,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Max Reitz" <mreitz@redhat.com>
Subject: [Qemu-devel] [PATCH 0/2] block/file-posix: Reduce xfsctl() use
Date: Fri, 23 Aug 2019 15:03:39 +0200	[thread overview]
Message-ID: <20190823130341.21550-1-mreitz@redhat.com> (raw)

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

-- 
2.21.0