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Lunev" Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, Vladimir Sementsov-Ogievskiy , John Snow , Andrey Drobyshev Subject: Re: [PATCH v4 09/12] block/block-copy: merge the two backup scan steps into block_copy_prescan() Message-ID: References: <20261030010613.1612771-1-den@openvz.org> <20261030010613.1612771-10-den@openvz.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261030010613.1612771-10-den@openvz.org> User-Agent: NeoMutt/20260616 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Fri, Oct 30, 2026 at 02:06:09AM +0100, Denis V. Lunev wrote: > From: Denis V. Lunev > > block_copy_reset_unallocated() and block_copy_calculate_zero_bitmap() > are both one step of the same scan and differ only in what they do with > the answer. Fold them into block_copy_prescan(), which drops unallocated > clusters from copy_bitmap while skip_unallocated is set, so > backup_scan_source() loses its per-mode branch. > > sync=top now walks the dirty areas the way full and bitmap do, so it no > longer queries what copy-before-write has already copied during the > scan. A failed query still fails sync=top, as nothing else can tell > which clusters to skip, and still leaves the area to be copied as data > otherwise. > > Suggested-by: Vladimir Sementsov-Ogievskiy > Signed-off-by: Denis V. Lunev > CC: Vladimir Sementsov-Ogievskiy > CC: John Snow > CC: Andrey Drobyshev > --- > block/backup.c | 7 +---- > block/block-copy.c | 63 ++++++++++++++------------------------ > include/block/block-copy.h | 9 ++---- > 3 files changed, 27 insertions(+), 52 deletions(-) Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. Virtualization: qemu.org | libguestfs.org