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[130.117.225.111]) by mx.google.com with ESMTPS id ffacd0b85a97d-48e2589ae14si5612633f8f.491.2026.10.21.08.42.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Oct 2026 08:42:06 -0700 (PDT) Received-SPF: pass (google.com: domain of khorenko@virtuozzo.com designates 130.117.225.111 as permitted sender) client-ip=130.117.225.111; Authentication-Results: mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=relay header.b=KqxjYDyO; spf=pass (google.com: domain of khorenko@virtuozzo.com designates 130.117.225.111 as permitted sender) smtp.mailfrom=khorenko@virtuozzo.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Message-Id:Date:From:Subject:Content-Type: MIME-Version; bh=PwW69nleBhyB5WYwh9MO0MwWla8bCw8lVBxXitUdzO8=; b=KqxjYDyOFGZy yKEwVfMJ6XIBBz+/RD5vdMmeHHDXprQcYcIzhHaljYe2A1ABOeAAVIBsAjMjrypBSsYeJGr3nGRKl PocB6oRVrFghTQcMYh8fyk5gGLPjFaP/hVMU1/BjdCZRuzKVoyZnp1feb46vTR8eauvkUBPQpX8X0 JIjBQGtdBMQuBFSj/NLNLXC5Gg8C9lRAmb31+048MyWe6lpBQfgBPROLGGrFnHxNmDw9RQw0WxplL 3A+DAuUQnmw0pGOFR8emUnvK8bj+pfLEDAzwik5TlKvfk6RayElvshsjfaDEaOVUiRFHgj7wrR08G eWOUp1d9K23qkjMq8wYYEw==; Received: from ch-demo-asa.virtuozzo.com ([130.117.225.8] helo=f0.sw.ru) by relay.virtuozzo.com with esmtp (Exim 4.96) (envelope-from ) id 1xJYOU-007X7J-23; Wed, 21 Oct 2026 17:42:05 +0200 MIME-Version: 1.0 From: Konstantin Khorenko To: Alexander Ivanov In-Reply-To: <20261010124642.927044-2-alexander.ivanov@virtuozzo.com> References: <20261010124642.927044-1-alexander.ivanov@virtuozzo.com> <20261010124642.927044-2-alexander.ivanov@virtuozzo.com> Date: Wed, 21 Oct 2026 17:42:02 +0200 Message-Id: <179259732233.3864599.11791979123677362750.b4-review@b4> X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1209; i=khorenko@virtuozzo.com; h=from:subject:message-id; bh=1WQiiquGoiGhgx+Uf4m57TPMFM1b1YWnxHcAJSxFv74=; b=owEBbQKS/ZANAwAKAVGWCkf5YVwqAcsmYgBq2N1MRIf9Hki48lmKztmn6vxDSLQw8rQ6D7rJk Kyf7VL//rKJAjMEAAEKAB0WIQRWD23IPcXT0GO9CCxRlgpH+WFcKgUCatjdTAAKCRBRlgpH+WFc Kk4hD/wNfc8kR4tCk9zirwDVb8bui2NUjKH43qgmRQOaYUwg2xxZKxqFY6t2ioZttd6ibWsHQeK 2mjFkxyvQnT92B789R5Va/20+3YWrYkiUEklQ3lEjqHKYbYkQmO47ETXENpss9cwpDbDAcZKx6c bD56F0H4bn4MVmz6dcdonyskgx8BZAOc3ksAtWyEWE+fBA/DUHwZvKJaLrO8MZ1PkHfYIK5tF3a sGd4LW+OGbX4/Wb4Z0Nvz3UAJp7f3GTwWmrER4MNPv5YJd+ITN6qc/h2vn2FQbiH3aqmB6hpcnu oQK3F8nevmR8F6wNgtVaGe/FKhRfSG/vwAhvwrdVuCzzX1q5pOr0t9UhoQJmTmmTUnLtXha/dqk VJH3uusAAh4axVm18LDbP5LSK3vqzgnPEK5lV2P5/HkiXb/gWkARy3agUoAizBvD8cLCzkaRN3P aiZ71InCDyFiEkptSNRcCYS2lB3mUrfmrWi05ZWWdKGdV4XOE3KADxTTc3Y694e86a/UO1c+WQV 6EeBeDrZptqL3S9ycxb4du3FL/2mMGSwqBlvXdaDIsxv/RTVwWAKtd3qIJYVgrH2EYv0qF2uIEt JLqVXapMn6ueEkllpOOIMe/+7qbJI5J5U/C3EyfPLwfDnQnAD05ihNRyHRgKn4WL3UKIG+78VDC r1+nENdM8X4uN7A== X-Developer-Key: i=khorenko@virtuozzo.com; a=openpgp; fpr=560F6DC83DC5D3D063BD082C51960A47F9615C2A X-OZ-Fwd: true Cc: devel@openvz.org Subject: Re: [Devel] [PATCH hci-8.1 v5 1/3] dm-qcow2: add qcow2_md_page_read_sync() helper X-BeenThere: devel@openvz.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: OpenVZ development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: devel-bounces@openvz.org Errors-To: devel-bounces@openvz.org > + * The caller must ensure no read of this page is in flight > + * (e.g., the device is suspended): if the page is cached but > + * not MD_UPTODATE yet, qcow2_md_page_find_or_postpone() returns > + * NULL and the following insert fails. The requirement is stronger: nobody else may look this page up while the helper runs. A qio that finds the page before MD_UPTODATE is set gets queued on md->wait_list, which this helper never wakes. On the error path the page is freed with that qio still on it. Neither caller can hit this today, but the comment should say "no concurrent lookup" rather than "no read in flight". > + ret = qcow2_rw_page_sync(READ, qcow2, id, (*md)->page); > + spin_lock_irq(&qcow2->md_pages_lock); > + if (ret) > + qcow2_md_page_erase(qcow2, *md); > + else > + (*md)->status |= MD_UPTODATE; > + spin_unlock_irq(&qcow2->md_pages_lock); > + if (ret) > + qcow2_free_md_page(*md); > + return ret; On both error paths *md is left pointing to freed memory: here, and on -EEXIST from qcow2_alloc_and_insert_md_page(). Please set *md = NULL there. -- Konstantin Khorenko _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel