From patchwork Fri Oct 20 21:56:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Drobyshev X-Patchwork-Id: 13431235 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7E69FC001DF for ; Fri, 20 Oct 2023 21:58:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qtxTv-0003pR-9m; Fri, 20 Oct 2023 17:56:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qtxTs-0003nm-RZ; Fri, 20 Oct 2023 17:56:32 -0400 Received: from relay.virtuozzo.com ([130.117.225.111]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qtxTq-0008G0-Iw; Fri, 20 Oct 2023 17:56:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=MIME-Version:Message-Id:Date:Subject:From: Content-Type; bh=AAm3BCi7oLK+rMtTaRnf4YstYpBZyRvRpC4m7z5RCrM=; b=Spc48BusaTgy M2MveG7EpevasYorRVBbYmuwedD8zP1/iGbmEnZwwZcXVtgSJp/o70vPjv4fZ/mtojLoy1xWvdZiw fpTBjmscgIIu9mW+inf9EbmSc0GUNXHycQl31xCMQuTIWGowuzsY1g+IKPooWrxPRpr/mHsXne2xo h5pUJOLhfey1IOW0zFErn4feXRZbEZRre63H9sG7c+q1kUL4J7/x6hX5VVZCipmi3ulbraD8g5gFp PHi6KGc/pA6DgsYFCTxWq7TLpgQ2kXtBZrJoYea4V594TePJUTlCl0blRd/hRd+c28wa8jlIVrJiR W/J280PSxSPN4dwO7HCopw==; Received: from [130.117.225.1] (helo=dev005.ch-qa.vzint.dev) by relay.virtuozzo.com with esmtp (Exim 4.96) (envelope-from ) id 1qtxTT-00A9pF-26; Fri, 20 Oct 2023 23:56:20 +0200 From: Andrey Drobyshev To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, hreitz@redhat.com, kwolf@redhat.com, eblake@redhat.com, berto@igalia.com, andrey.drobyshev@virtuozzo.com, den@virtuozzo.com Subject: [PATCH 3/7] qcow2: zeroize the entire cluster when there're no non-zero subclusters Date: Sat, 21 Oct 2023 00:56:18 +0300 Message-Id: <20231020215622.789260-4-andrey.drobyshev@virtuozzo.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20231020215622.789260-1-andrey.drobyshev@virtuozzo.com> References: <20231020215622.789260-1-andrey.drobyshev@virtuozzo.com> MIME-Version: 1.0 Received-SPF: pass client-ip=130.117.225.111; envelope-from=andrey.drobyshev@virtuozzo.com; helo=relay.virtuozzo.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org When zeroizing the last non-zero subclusters within single cluster, it makes sense to go zeroize the entire cluster and go down zero_in_l2_slice() path right away. That way we'd also update the corresponding refcount table. Signed-off-by: Andrey Drobyshev Reviewed-by: Hanna Czenczek --- block/qcow2-cluster.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 8801856b93..7c6fa5524c 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -2145,7 +2145,7 @@ zero_in_l2_slice(BlockDriverState *bs, uint64_t offset, static int coroutine_fn GRAPH_RDLOCK zero_l2_subclusters(BlockDriverState *bs, uint64_t offset, - unsigned nb_subclusters) + unsigned nb_subclusters, int flags) { BDRVQcow2State *s = bs->opaque; uint64_t new_l2_bitmap; @@ -2161,6 +2161,17 @@ zero_l2_subclusters(BlockDriverState *bs, uint64_t offset, new_l2_bitmap |= QCOW_OFLAG_SUB_ZERO_RANGE(sc, sc + nb_subclusters); new_l2_bitmap &= ~QCOW_OFLAG_SUB_ALLOC_RANGE(sc, sc + nb_subclusters); + /* + * If there're no non-zero subclusters left, we might as well zeroize + * the entire cluster. That way we'd also update the refcount table. + */ + if ((new_l2_bitmap & QCOW_L2_BITMAP_ALL_ZEROES) == + QCOW_L2_BITMAP_ALL_ZEROES) { + qcow2_cache_put(s->l2_table_cache, (void **) &scri.l2_slice); + return zero_in_l2_slice(bs, QEMU_ALIGN_DOWN(offset, s->cluster_size), + 1, flags); + } + if (new_l2_bitmap != scri.l2_bitmap) { set_l2_bitmap(s, scri.l2_slice, scri.l2_index, new_l2_bitmap); qcow2_cache_entry_mark_dirty(s->l2_table_cache, scri.l2_slice); @@ -2221,7 +2232,7 @@ int coroutine_fn qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, if (head) { ret = zero_l2_subclusters(bs, offset - head, - size_to_subclusters(s, head)); + size_to_subclusters(s, head), flags); if (ret < 0) { goto fail; } @@ -2242,7 +2253,8 @@ int coroutine_fn qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, } if (tail) { - ret = zero_l2_subclusters(bs, end_offset, size_to_subclusters(s, tail)); + ret = zero_l2_subclusters(bs, end_offset, + size_to_subclusters(s, tail), flags); if (ret < 0) { goto fail; }