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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 82CC6C433E0 for ; Fri, 22 May 2020 15:16:02 +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 3E470205CB for ; Fri, 22 May 2020 15:16:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RcPpL6ye" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E470205CB 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]:55854 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jc9Oz-00044g-G0 for qemu-devel@archiver.kernel.org; Fri, 22 May 2020 11:16:01 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33700) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jc9Nx-0003H0-R9 for qemu-devel@nongnu.org; Fri, 22 May 2020 11:14:57 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:58148 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jc9Nw-00022U-SI for qemu-devel@nongnu.org; Fri, 22 May 2020 11:14:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590160496; 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=pygucWuFaQBD7sZN54bwwioIVktyp3oelb8TGfMdeXs=; b=RcPpL6yeDIGLCKCYFKcUuJYZEPg4Tgb1IxyPrBFWfMhbv2OdBA/uTVWlmFswDpz0AD7lUh c9vTUdN1c+CaKKteDEtiG+rQrQqQlurdCSlesUgA1qwsZWq7osVEy/vWyb99H/qURjkOX5 QJ5eJys8tbHTDQ4NUl93SImnCAMKgxU= 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-136-RsGcVkwuOC2ZCZl_ZOa1uA-1; Fri, 22 May 2020 11:14:47 -0400 X-MC-Unique: RsGcVkwuOC2ZCZl_ZOa1uA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AA7D1100CCC2; Fri, 22 May 2020 15:14:45 +0000 (UTC) Received: from [10.3.112.88] (ovpn-112-88.phx2.redhat.com [10.3.112.88]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5EDB65C1D3; Fri, 22 May 2020 15:14:37 +0000 (UTC) Subject: Re: [PATCH v3 08/17] block/io: support int64_t bytes in bdrv_aligned_preadv() To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20200430111033.29980-1-vsementsov@virtuozzo.com> <20200430111033.29980-9-vsementsov@virtuozzo.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <9143ff10-cba2-bcc2-c48c-eac73446b159@redhat.com> Date: Fri, 22 May 2020 10:14:36 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200430111033.29980-9-vsementsov@virtuozzo.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=205.139.110.61; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/22 11:11:51 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] 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_H2=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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: kwolf@redhat.com, fam@euphon.net, integration@gluster.org, berto@igalia.com, pavel.dovgaluk@ispras.ru, dillaman@redhat.com, qemu-devel@nongnu.org, sw@weilnetz.de, pl@kamp.de, ronniesahlberg@gmail.com, mreitz@redhat.com, den@openvz.org, sheepdog@lists.wpkg.org, stefanha@redhat.com, namei.unix@gmail.com, pbonzini@redhat.com, jsnow@redhat.com, ari@tuxera.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 4/30/20 6:10 AM, Vladimir Sementsov-Ogievskiy wrote: > We are generally moving to int64_t for both offset and bytes parameters > on all io paths. > > Main motivation is realization of 64-bit write_zeroes operation for > fast zeroing large disk chunks, up to the whole disk. > > We chose signed type, to be consistent with off_t (which is signed) and > with possibility for signed return type (where negative value means > error). > > So, prepare bdrv_aligned_preadv() now. > > Make byte variable in bdrv_padding_rmw_read() int64_t, as it defined > only to be passed to bdrv_aligned_preadv(). > > Series: 64bit-block-status > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > block/io.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/block/io.c b/block/io.c > index 6990d8cabe..d336e4e691 100644 > --- a/block/io.c > +++ b/block/io.c > @@ -1250,16 +1250,17 @@ err: > * reads; any other features must be implemented by the caller. > */ > static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, > - BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, > + BdrvTrackedRequest *req, int64_t offset, int64_t bytes, > int64_t align, QEMUIOVector *qiov, size_t qiov_offset, int flags) > { Callers: bdrv_padding_rmw_read() - passes int64_t (uint64_t before this patch), which in turn is bounded by request_alignment (still 32-bit) or BdrvRequestPadding.buf_len (size_t, but also constrained by creation to 32-bit) - safe bdrv_do_preadv_part() - passes unsigned int - safe > BlockDriverState *bs = child->bs; > int64_t total_bytes, max_bytes; > int ret = 0; > - uint64_t bytes_remaining = bytes; > + int64_t bytes_remaining = bytes; > int max_transfer; > > assert(is_power_of_2(align)); > + assert(offset >= 0 && bytes >= 0); Use within the function: the new assertion added here does not check for whether offset+bytes is positive; I would suggest we strengthen it to instead be: assert(offset >= 0 && (uint64_t) bytes <= INT64_MAX - offset); ret = bdrv_is_allocated(bs, offset, bytes, &pnum); - takes int64_t, safe if (!ret || pnum != bytes) { ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, qiov_offset, flags); - takes int64_t, safe if (bytes <= max_bytes && bytes <= max_transfer) { ret = bdrv_driver_preadv(bs, offset, bytes, qiov, qiov_offset, 0); - takes int64_t, safe > assert((offset & (align - 1)) == 0); > assert((bytes & (align - 1)) == 0); > assert((bs->open_flags & BDRV_O_NO_IO) == 0); > @@ -1315,7 +1316,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, > } > > while (bytes_remaining) { > - int num; > + int64_t num; > > if (max_bytes) { > num = MIN(bytes_remaining, MIN(max_bytes, max_transfer)); - safe, bounded by max_transfer which is <= INT_MAX earlier in the function ret = bdrv_driver_preadv(bs, offset + bytes - bytes_remaining, num, qiov, bytes - bytes_remaining, 0); - takes int64_t, and num is capped by max_transfer - safe ret = qemu_iovec_memset(qiov, bytes - bytes_remaining, 0, bytes_remaining); - takes size_t, risky for 32-bit platforms. Works because we checked that all our callers are still bounded by 32-bits, but we should consider adding an assertion that bytes <= SIZE_MAX so that even when our callers are updated in later patches, we know that we are still fragmenting requests appropriately on 32-bit platforms > @@ -1416,7 +1417,7 @@ static int bdrv_padding_rmw_read(BdrvChild *child, > assert(req->serialising && pad->buf); > > if (pad->head || pad->merge_reads) { > - uint64_t bytes = pad->merge_reads ? pad->buf_len : align; > + int64_t bytes = pad->merge_reads ? pad->buf_len : align; > > qemu_iovec_init_buf(&local_qiov, pad->buf, bytes); > > Preferably with the suggested assertions added, Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org