[{"id":3683380,"web_url":"http://patchwork.ozlabs.org/comment/3683380/","msgid":"","list_archive_url":null,"date":"2026-04-28T11:00:29","subject":"Re: [PATCH 0/4] qcow2: Fix corruption on discard during write with\n COW","submitter":{"id":68167,"url":"http://patchwork.ozlabs.org/api/people/68167/","name":"Denis V. Lunev","email":"den@virtuozzo.com"},"content":"On 4/27/26 19:05, Kevin Wolf wrote:\n> This is an alternative fix for the corruption problem reported by Denis:\n> https://patchew.org/QEMU/20260421155628.3600671-1-den@openvz.org/\n>\n> I think it really is a qcow2 level bug and should be fixed on the qcow2\n> level. The test is also more targeted than just doing random I/O for a\n> while, and therefore runs faster and documents the problem better.\n>\n> Kevin Wolf (4):\n> commit: Drain nodes across all of bdrv_commit()\n> qemu-io: Add 'aio_discard' command\n> qcow2: Fix corruption on discard during write with COW\n> iotests/046: Test that discard/write_zeroes wait for dependencies\n>\n> block/commit.c | 10 +++-\n> block/qcow2-cluster.c | 52 ++++++++++++++++-\n> qemu-io-cmds.c | 113 +++++++++++++++++++++++++++++++++++++\n> tests/qemu-iotests/046 | 46 +++++++++++++++\n> tests/qemu-iotests/046.out | 36 ++++++++++++\n> 5 files changed, 252 insertions(+), 5 deletions(-)\n>\nwith a 2 small nickpicks fixed\n\nReviewed-by: Denis V. Lunev \nTested-by: Denis V. 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