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From: no-reply@sashiko.virtuozzo.com
To: Alexander Ivanov <alexander.ivanov@virtuozzo.com>,
	andrey.zhadchenko@virtuozzo.com
Cc: devel@openvz.org
Subject: Re: [Devel] [PATCH hci-8.1 v9 05/10] dm-qcow2: flush lower metadata before clearing its dirty bit on merge failure
Date: Wed, 28 Oct 2026 15:14:27 +0000	[thread overview]
Message-ID: <010701a18313adda-3a1a43ae-6141-4c9e-85ca-f15808147b5c-000000@eu-central-1.amazonses.com> (raw)
In-Reply-To: <20261028150645.3222391-6-alexander.ivanov@virtuozzo.com>

> When qcow2_merge_common() fails, qcow2_merge_backward_work() clears the
> dirty bit of the lower image right away. qcow2_service_iter() waits only
> for the service qios, so delayed md writeback of the lower image may
> still be pending. With kernel_sets_dirty_bit, a crash at that point
> leaves the lower image marked clean on disk with L2 tables and refblocks
> that lag behind the merged data.
> 
> A failed md writeback of the lower image is also missed:
> md_writeback_error is set only by qcow2_flush_deferred_activity(), so
> the next resume is not refused.
> 
> Flush the deferred activity of the lower image before writing its
> header, as qcow2_merge_backward_complete() does.
> 
> https://virtuozzo.atlassian.net/browse/VSTOR-148171
> Feature: dm-qcow2: block device over QCOW2 files driver
> Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.vzint.dev/#/patchset/20261028150645.3222391-1-alexander.ivanov@virtuozzo.com?part=5


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  reply	other threads:[~2026-10-28 15:15 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-28 15:06 [Devel] [PATCH hci-8.1 v9 00/10] dm-qcow2: truncate unused tail of image on suspend Alexander Ivanov
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 01/10] dm-qcow2: add qcow2_md_page_read_sync() helper Alexander Ivanov
2026-10-28 15:12   ` no-reply
2026-11-03 17:50   ` Konstantin Khorenko
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 02/10] dm-qcow2: drop duplicate prefix from QC_ERR/QC_INFO messages Alexander Ivanov
2026-10-28 15:10   ` no-reply
2026-11-03 17:50   ` Konstantin Khorenko
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 03/10] dm-qcow2: extend the file for a new refblock in allocate_cluster() Alexander Ivanov
2026-10-28 15:11   ` no-reply
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 04/10] dm-qcow2: complete wbd before ending the data qio Alexander Ivanov
2026-10-28 15:14   ` no-reply
2026-11-03 17:50   ` Konstantin Khorenko
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 05/10] dm-qcow2: flush lower metadata before clearing its dirty bit on merge failure Alexander Ivanov
2026-10-28 15:14   ` no-reply [this message]
2026-11-03 17:50   ` Konstantin Khorenko
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 06/10] dm-qcow2: keep the dirty bit of an image that needs check Alexander Ivanov
2026-10-28 15:16   ` no-reply
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 07/10] dm-qcow2: fix md page cleanup on failed reftable relocation Alexander Ivanov
2026-10-28 15:16   ` no-reply
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 08/10] dm-qcow2: flag the image for check if reftable relocation fails late Alexander Ivanov
2026-10-28 15:17   ` no-reply
2026-10-29  7:18     ` Alexander Ivanov
2026-11-03 17:50   ` Konstantin Khorenko
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 09/10] dm-qcow2: flag the image for check after a reverted L1/L2 writeback Alexander Ivanov
2026-10-28 15:19   ` no-reply
2026-10-29  7:27     ` Alexander Ivanov
2026-11-03 17:50   ` Konstantin Khorenko
2026-10-28 15:06 ` [Devel] [PATCH hci-8.1 v9 10/10] dm-qcow2: truncate unused tail of image on suspend Alexander Ivanov
2026-10-28 15:21   ` no-reply
2026-11-03 17:50   ` Konstantin Khorenko
2026-10-29 10:55 ` [Devel] [PATCH hci-8.1 v9 00/10] " Andrey Zhadchenko
2026-11-03 17:50 ` Konstantin Khorenko

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