From nobody Mon Feb 9 12:26:01 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1495658094388320.2811021826453; Wed, 24 May 2017 13:34:54 -0700 (PDT) Received: from localhost ([::1]:56726 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dDczc-0007wX-UR for importer@patchew.org; Wed, 24 May 2017 16:34:52 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60702) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dDcty-0003hC-F3 for qemu-devel@nongnu.org; Wed, 24 May 2017 16:29:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dDctx-00061t-8M for qemu-devel@nongnu.org; Wed, 24 May 2017 16:29:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55590) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dDctt-0005ys-Mn; Wed, 24 May 2017 16:28:57 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A9D3513A60; Wed, 24 May 2017 20:28:56 +0000 (UTC) Received: from red.redhat.com (ovpn-122-27.rdu2.redhat.com [10.10.122.27]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2E6A71710F; Wed, 24 May 2017 20:28:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A9D3513A60 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=eblake@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com A9D3513A60 From: Eric Blake To: qemu-devel@nongnu.org Date: Wed, 24 May 2017 15:28:40 -0500 Message-Id: <20170524202842.26724-4-eblake@redhat.com> In-Reply-To: <20170524202842.26724-1-eblake@redhat.com> References: <20170524202842.26724-1-eblake@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 24 May 2017 20:28:56 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 3/5] block: Allow NULL file for bdrv_get_block_status() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Jeff Cody , mreitz@redhat.com, Stefan Hajnoczi , jsnow@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Not all callers care about which BDS owns the mapping for a given range of the file. This patch merely simplifies the callers by consolidating the logic in the common call point, while guaranteeing a non-NULL file to all the driver callbacks, for no semantic change. However, this will also set the stage for a future cleanup: when a caller does not care about which BDS owns an offset, it would be nice to allow the driver to optimize things to not have to return BDRV_BLOCK_OFFSET_VALID in the first place. In the case of fragmented allocation (for example, it's fairly easy to create a qcow2 image where consecutive guest addresses are not at consecutive host addresses), the current contract requires bdrv_get_block_status() to clamp *pnum to the limit where host addresses are no longer consecutive, but allowing a NULL file means that *pnum could be set to the full length of known-allocated data. Signed-off-by: Eric Blake --- v2: new patch --- block/io.c | 15 +++++++++------ block/mirror.c | 3 +-- block/qcow2.c | 4 +--- qemu-img.c | 10 ++++------ 4 files changed, 15 insertions(+), 17 deletions(-) diff --git a/block/io.c b/block/io.c index 8e6c3fe..eea74cb 100644 --- a/block/io.c +++ b/block/io.c @@ -706,7 +706,6 @@ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags f= lags) { int64_t target_sectors, ret, nb_sectors, sector_num =3D 0; BlockDriverState *bs =3D child->bs; - BlockDriverState *file; int n; target_sectors =3D bdrv_nb_sectors(bs); @@ -719,7 +718,7 @@ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags f= lags) if (nb_sectors <=3D 0) { return 0; } - ret =3D bdrv_get_block_status(bs, sector_num, nb_sectors, &n, &fil= e); + ret =3D bdrv_get_block_status(bs, sector_num, nb_sectors, &n, NULL= ); if (ret < 0) { error_report("error getting block status at sector %" PRId64 "= : %s", sector_num, strerror(-ret)); @@ -1737,8 +1736,9 @@ typedef struct BdrvCoGetBlockStatusData { * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors g= oes * beyond the end of the disk image it will be clamped. * - * If returned value is positive and BDRV_BLOCK_OFFSET_VALID bit is set, '= file' - * points to the BDS which the sector range is allocated in. + * If returned value is positive, BDRV_BLOCK_OFFSET_VALID bit is set, and + * 'file' is non-NULL, then '*file' points to the BDS which the sector ran= ge + * is allocated in. */ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, int64_t sector_num, @@ -1748,7 +1748,11 @@ static int64_t coroutine_fn bdrv_co_get_block_status= (BlockDriverState *bs, int64_t total_sectors; int64_t n; int64_t ret, ret2; + BlockDriverState *tmpfile; + if (!file) { + file =3D &tmpfile; + } *file =3D NULL; total_sectors =3D bdrv_nb_sectors(bs); if (total_sectors < 0) { @@ -1916,9 +1920,8 @@ int64_t bdrv_get_block_status(BlockDriverState *bs, int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_nu= m, int nb_sectors, int *pnum) { - BlockDriverState *file; int64_t ret =3D bdrv_get_block_status(bs, sector_num, nb_sectors, pnum, - &file); + NULL); if (ret < 0) { return ret; } diff --git a/block/mirror.c b/block/mirror.c index e86f8f8..4563ba7 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -392,7 +392,6 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlo= ckJob *s) while (nb_chunks > 0 && sector_num < end) { int64_t ret; int io_sectors, io_sectors_acct; - BlockDriverState *file; enum MirrorMethod { MIRROR_METHOD_COPY, MIRROR_METHOD_ZERO, @@ -402,7 +401,7 @@ static uint64_t coroutine_fn mirror_iteration(MirrorBlo= ckJob *s) assert(!(sector_num % sectors_per_chunk)); ret =3D bdrv_get_block_status_above(source, NULL, sector_num, nb_chunks * sectors_per_chunk, - &io_sectors, &file); + &io_sectors, NULL); if (ret < 0) { io_sectors =3D MIN(nb_chunks * sectors_per_chunk, max_io_secto= rs); } else if (ret & BDRV_BLOCK_DATA) { diff --git a/block/qcow2.c b/block/qcow2.c index b3ba5da..8e9e29b 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2448,7 +2448,6 @@ static bool is_zero_sectors(BlockDriverState *bs, int= 64_t start, uint32_t count) { int nr; - BlockDriverState *file; int64_t res; if (start + count > bs->total_sectors) { @@ -2458,8 +2457,7 @@ static bool is_zero_sectors(BlockDriverState *bs, int= 64_t start, if (!count) { return true; } - res =3D bdrv_get_block_status_above(bs, NULL, start, count, - &nr, &file); + res =3D bdrv_get_block_status_above(bs, NULL, start, count, &nr, NULL); return res >=3D 0 && (res & BDRV_BLOCK_ZERO) && nr =3D=3D count; } diff --git a/qemu-img.c b/qemu-img.c index 5aef8ef..cb78696 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -1398,7 +1398,6 @@ static int img_compare(int argc, char **argv) for (;;) { int64_t status1, status2; - BlockDriverState *file; nb_sectors =3D sectors_to_process(total_sectors, sector_num); if (nb_sectors <=3D 0) { @@ -1406,7 +1405,7 @@ static int img_compare(int argc, char **argv) } status1 =3D bdrv_get_block_status_above(bs1, NULL, sector_num, total_sectors1 - sector_num, - &pnum1, &file); + &pnum1, NULL); if (status1 < 0) { ret =3D 3; error_report("Sector allocation test failed for %s", filename1= ); @@ -1416,7 +1415,7 @@ static int img_compare(int argc, char **argv) status2 =3D bdrv_get_block_status_above(bs2, NULL, sector_num, total_sectors2 - sector_num, - &pnum2, &file); + &pnum2, NULL); if (status2 < 0) { ret =3D 3; error_report("Sector allocation test failed for %s", filename2= ); @@ -1615,15 +1614,14 @@ static int convert_iteration_sectors(ImgConvertStat= e *s, int64_t sector_num) n =3D MIN(s->total_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS); if (s->sector_next_status <=3D sector_num) { - BlockDriverState *file; if (s->target_has_backing) { ret =3D bdrv_get_block_status(blk_bs(s->src[src_cur]), sector_num - src_cur_offset, - n, &n, &file); + n, &n, NULL); } else { ret =3D bdrv_get_block_status_above(blk_bs(s->src[src_cur]), N= ULL, sector_num - src_cur_offset, - n, &n, &file); + n, &n, NULL); } if (ret < 0) { return ret; --=20 2.9.4