From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 923F2C48BE5 for ; Thu, 17 Jun 2021 15:54:39 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0629B613F2 for ; Thu, 17 Jun 2021 15:54:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0629B613F2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59614 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ltuLl-0008LK-V1 for qemu-devel@archiver.kernel.org; Thu, 17 Jun 2021 11:54:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43758) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltuK9-0005S6-A1 for qemu-devel@nongnu.org; Thu, 17 Jun 2021 11:52:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:38219) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltuK5-0001DL-O3 for qemu-devel@nongnu.org; Thu, 17 Jun 2021 11:52:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623945172; 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; bh=EbQTSkOZ+GN+TXbgcnDjhJjuIcA0PdDOaxmXokgeYXM=; b=Brs1zsSOu7FN7G6ZE4Z0dqLWnyZPX8RkmM+JPoOcn7GUUUNHPzsBV3fw9qujs1wLRPukPP AiNY4s/84nLjjqdczjPcKqfIeFsAUCjLOonrPUCgH/9/O1Laumc+2iillcQwNpDfh4aQTx v3EiM//PkPwHR+m5DpmT8PZbmalpTyU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-322-JcYR79RsN4eskzCZL1_x0A-1; Thu, 17 Jun 2021 11:52:49 -0400 X-MC-Unique: JcYR79RsN4eskzCZL1_x0A-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 05263801106; Thu, 17 Jun 2021 15:52:49 +0000 (UTC) Received: from localhost (ovpn-114-231.ams2.redhat.com [10.36.114.231]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A5A555D9C6; Thu, 17 Jun 2021 15:52:48 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH 0/6] block: block-status cache for data regions Date: Thu, 17 Jun 2021 17:52:41 +0200 Message-Id: <20210617155247.442150-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.197, 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_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi, We’ve already had two attempts at introducing a block-status cache for data regions (https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg06451.html, "file-posix: Cache lseek result for data regions"; https://lists.nongnu.org/archive/html/qemu-block/2021-02/msg00934.html, "file-posix: Cache next hole"), both of which were local to file-posix. I have a gitlab issue assigned to me (https://gitlab.com/qemu-project/qemu/-/issues/307), so I suppose it’s time for round three. This series tries to address what I gathered from the reviews for both: (1) We should try to have this cache in the general block layer for all protocol drivers; (2) Just to be sure, we should have a mutex for it; (3) External writers don’t matter if we just cache data regions, because (for a protocol node) reporting a zero region as data isn’t fatal. Patch 1 is clean-up, patch 2 is the main one, patches 3 to 6 make it more useful: Some protocol drivers force-clamp the returned *pnum based on the @bytes parameter, but that’s completely unnecessary, because bdrv_co_block_status() will clamp the value, too. It’s beneficial to return as large a *pnum value as possible to bdrv_co_block_status(), so our cache can be more effective. Max Reitz (6): block: Drop BDS comment regarding bdrv_append() block: block-status cache for data regions block/file-posix: Do not force-cap *pnum block/gluster: Do not force-cap *pnum block/nbd: Do not force-cap *pnum block/iscsi: Do not force-cap *pnum include/block/block_int.h | 21 ++++++++-- block.c | 2 + block/file-posix.c | 7 ++-- block/gluster.c | 7 ++-- block/io.c | 80 +++++++++++++++++++++++++++++++++++++-- block/iscsi.c | 3 -- block/nbd.c | 2 +- 7 files changed, 105 insertions(+), 17 deletions(-) -- 2.31.1