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From: Hanna Czenczek <hreitz@redhat.com>
To: qemu-block@nongnu.org
Cc: qemu-devel@nongnu.org, Hanna Czenczek <hreitz@redhat.com>,
	Kevin Wolf <kwolf@redhat.com>
Subject: [PATCH 0/2] block/fuse: Let PUNCH_HOLE write zeroes
Date: Mon, 27 Feb 2023 11:47:23 +0100	[thread overview]
Message-ID: <20230227104725.33511-1-hreitz@redhat.com> (raw)

Hi,

https://gitlab.com/qemu-project/qemu/-/issues/1507 reports a bug in FUSE
exports: fallocate(PUNCH_HOLE) is implemented with blk_pdiscard(), but
its man page documents that a successful call will result in the data
being read as zero.  blk_pdiscard() does not guarantee this, so we must
use blk_pwrite_zeroes() instead (with MAY_UNMAP | NO_FALLBACK, which
differentiates it from fallocate(ZERO_RANGE)).

Patch 2 adds a regression test.


Hanna Czenczek (2):
  block/fuse: Let PUNCH_HOLE write zeroes
  iotests/308: Add test for 'write -zu'

 block/export/fuse.c        | 11 +++++++++-
 tests/qemu-iotests/308     | 43 ++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/308.out | 35 +++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 1 deletion(-)

-- 
2.39.1



             reply	other threads:[~2023-02-27 10:48 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-27 10:47 Hanna Czenczek [this message]
2023-02-27 10:47 ` [PATCH 1/2] block/fuse: Let PUNCH_HOLE write zeroes Hanna Czenczek
2023-02-27 10:47 ` [PATCH 2/2] iotests/308: Add test for 'write -zu' Hanna Czenczek
2023-03-07 14:23 ` [PATCH 0/2] block/fuse: Let PUNCH_HOLE write zeroes Kevin Wolf

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