From patchwork Wed Dec 11 21:08:16 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 300448 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id EEB562C0185 for ; Thu, 12 Dec 2013 09:05:38 +1100 (EST) Received: from localhost ([::1]:60311 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vqr8u-0008Pd-5d for incoming@patchwork.ozlabs.org; Wed, 11 Dec 2013 16:16:28 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43907) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vqr1p-0007PP-Pe for qemu-devel@nongnu.org; Wed, 11 Dec 2013 16:09:15 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Vqr1j-0000iq-QO for qemu-devel@nongnu.org; Wed, 11 Dec 2013 16:09:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:24701) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vqr1j-0000ik-Jg for qemu-devel@nongnu.org; Wed, 11 Dec 2013 16:09:03 -0500 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rBBL90kY024696 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 11 Dec 2013 16:09:00 -0500 Received: from dhcp-200-207.str.redhat.com (ovpn-116-104.ams2.redhat.com [10.36.116.104]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id rBBL8d8s028102; Wed, 11 Dec 2013 16:08:58 -0500 From: Kevin Wolf To: qemu-devel@nongnu.org Date: Wed, 11 Dec 2013 22:08:16 +0100 Message-Id: <1386796109-15264-10-git-send-email-kwolf@redhat.com> In-Reply-To: <1386796109-15264-1-git-send-email-kwolf@redhat.com> References: <1386796109-15264-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.25 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, pbonzini@redhat.com, pl@kamp.de, stefanha@redhat.com Subject: [Qemu-devel] [PATCH 09/22] block: Introduce bdrv_aligned_preadv() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This separates the part of bdrv_co_do_readv() that needs to happen before the request is modified to match the backend alignment, and a part that needs to be executed afterwards and passes the request to the BlockDriver. Signed-off-by: Kevin Wolf --- block.c | 61 +++++++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 43 insertions(+), 18 deletions(-) diff --git a/block.c b/block.c index b86e754..cbc9f6d 100644 --- a/block.c +++ b/block.c @@ -2700,26 +2700,24 @@ err: } /* - * Handle a read request in coroutine context + * Forwards an already correctly aligned request to the BlockDriver. This + * handles copy on read and zeroing after EOF; any other features must be + * implemented by the caller. */ -static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, - int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, - BdrvRequestFlags flags) +static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, + int64_t offset, unsigned int bytes, QEMUIOVector *qiov, int flags) { BlockDriver *drv = bs->drv; BdrvTrackedRequest req; int ret; - if (!drv) { - return -ENOMEDIUM; - } - if (bdrv_check_request(bs, sector_num, nb_sectors)) { - return -EIO; - } + int64_t sector_num = offset >> BDRV_SECTOR_BITS; + unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; - if (bs->copy_on_read) { - flags |= BDRV_REQ_COPY_ON_READ; - } + assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); + assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); + + /* Handle Copy on Read and associated serialisation */ if (flags & BDRV_REQ_COPY_ON_READ) { bs->copy_on_read_in_flight++; } @@ -2728,11 +2726,6 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, wait_for_overlapping_requests(bs, sector_num, nb_sectors); } - /* throttling disk I/O */ - if (bs->io_limits_enabled) { - bdrv_io_limits_intercept(bs, nb_sectors, false); - } - tracked_request_begin(&req, bs, sector_num, nb_sectors, false); if (flags & BDRV_REQ_COPY_ON_READ) { @@ -2749,6 +2742,7 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, } } + /* Forward the request to the BlockDriver */ if (!(bs->zero_beyond_eof && bs->growable)) { ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); } else { @@ -2789,6 +2783,37 @@ out: return ret; } +/* + * Handle a read request in coroutine context + */ +static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, + int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, + BdrvRequestFlags flags) +{ + BlockDriver *drv = bs->drv; + int ret; + + if (!drv) { + return -ENOMEDIUM; + } + if (bdrv_check_request(bs, sector_num, nb_sectors)) { + return -EIO; + } + + if (bs->copy_on_read) { + flags |= BDRV_REQ_COPY_ON_READ; + } + + /* throttling disk I/O */ + if (bs->io_limits_enabled) { + bdrv_io_limits_intercept(bs, nb_sectors, false); + } + + ret = bdrv_aligned_preadv(bs, sector_num << BDRV_SECTOR_BITS, + nb_sectors << BDRV_SECTOR_BITS, qiov, flags); + return ret; +} + int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) {