From patchwork Thu Apr 17 18:39:07 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 14056109 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 E18C7C369C9 for ; Thu, 17 Apr 2025 18:42:30 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1u5UBX-00042v-UN; Thu, 17 Apr 2025 14:42:03 -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 1u5UBV-00041x-1t for qemu-devel@nongnu.org; Thu, 17 Apr 2025 14:42:01 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1u5UBT-0002qt-Ln for qemu-devel@nongnu.org; Thu, 17 Apr 2025 14:42:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744915318; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NfqoMro0GIz5LImw8hVnGM/j3vZZ3MGIlfImJYmZAIM=; b=CqFifwEyjG4VAJ2OAsoybQf6NK1BDollG5K05Ivx4qFAILS7hxsi3MinS5lwbgjoLCOXss TE544kSXj0gbe7UqrXvZEfye8KteAs6VcyGvzMl0qYGGbrHBBbYHjSjJaQp3n2qKuz+EnP qDCUoS2c1l6jj6hpGhezRyQxCY5Yucs= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-250-3uGYGDo4MVKNvXSZO8uZ_g-1; Thu, 17 Apr 2025 14:41:55 -0400 X-MC-Unique: 3uGYGDo4MVKNvXSZO8uZ_g-1 X-Mimecast-MFC-AGG-ID: 3uGYGDo4MVKNvXSZO8uZ_g_1744915314 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5F54719560AF; Thu, 17 Apr 2025 18:41:54 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.121]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id E0B331955E96; Thu, 17 Apr 2025 18:41:50 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, vsementsov@yandex-team.ru, Kevin Wolf , Hanna Reitz Subject: [PATCH v2 02/11] file-posix: Handle zero block status hint better Date: Thu, 17 Apr 2025 13:39:07 -0500 Message-ID: <20250417184133.105746-15-eblake@redhat.com> In-Reply-To: <20250417184133.105746-13-eblake@redhat.com> References: <20250417184133.105746-13-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.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, 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_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=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: 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 Although the previous patch to change 'bool want_zero' into an enum made no semantic change, it is now time to differentiate. When the caller specifically wants to know what parts of the file read as zero, we need to use lseek and actually reporting holes, rather than short-circuiting and advertising full allocation. This change will be utilized in later patches to let mirroring optimize for the case when the destination already reads as zeroes. Signed-off-by: Eric Blake Reviewed-by: Stefan Hajnoczi --- block/file-posix.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/file-posix.c b/block/file-posix.c index 30129ec9b37..8f3e7a8304f 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -3217,7 +3217,8 @@ static int coroutine_fn raw_co_block_status(BlockDriverState *bs, return ret; } - if (mode != BDRV_BSTAT_PRECISE) { + if (mode == BDRV_BSTAT_ALLOCATED) { + /* There is no backing file - all bytes are allocated in this file. */ *pnum = bytes; *map = offset; *file = bs;