From nobody Wed Dec 17 05:41:16 2025 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.zohomail.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; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1520017056029392.79208089556823; Fri, 2 Mar 2018 10:57:36 -0800 (PST) Received: from localhost ([::1]:36868 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1erps6-0002e6-Uc for importer@patchew.org; Fri, 02 Mar 2018 13:57:34 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52366) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1erppy-00010r-JL for qemu-devel@nongnu.org; Fri, 02 Mar 2018 13:55:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1erppw-0002cP-P4 for qemu-devel@nongnu.org; Fri, 02 Mar 2018 13:55:22 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60088 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1erppq-0002Vy-Vs; Fri, 02 Mar 2018 13:55:15 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C7059402291E; Fri, 2 Mar 2018 18:55:13 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-117-66.ams2.redhat.com [10.36.117.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id A6965AB583; Fri, 2 Mar 2018 18:55:12 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 2 Mar 2018 19:54:15 +0100 Message-Id: <20180302185448.6314-5-kwolf@redhat.com> In-Reply-To: <20180302185448.6314-1-kwolf@redhat.com> References: <20180302185448.6314-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 02 Mar 2018 18:55:13 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 02 Mar 2018 18:55:13 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'kwolf@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PULL 04/37] file-posix: Switch to .bdrv_co_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: kwolf@redhat.com, qemu-devel@nongnu.org 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" From: Eric Blake We are gradually moving away from sector-based interfaces, towards byte-based. Update the file protocol driver accordingly. In want_zero mode, we continue to report fine-grained hole information (the caller wants as much mapping detail as possible); but when not in that mode, the caller prefers larger *pnum and merely cares about what offsets are allocated at this layer, rather than where the holes live. Since holes still read as zeroes at this layer (rather than deferring to a backing layer), we can take the shortcut of skipping lseek(), and merely state that all bytes are allocated. We can also drop redundant bounds checks that are already guaranteed by the block layer. Signed-off-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Fam Zheng Signed-off-by: Kevin Wolf --- block/file-posix.c | 64 +++++++++++++++++++++++++-------------------------= ---- 1 file changed, 30 insertions(+), 34 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index ca49c1a98a..f1591c3849 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -2131,25 +2131,24 @@ static int find_allocation(BlockDriverState *bs, of= f_t start, } =20 /* - * Returns the allocation status of the specified sectors. + * Returns the allocation status of the specified offset. * - * If 'sector_num' is beyond the end of the disk image the return value is= 0 - * and 'pnum' is set to 0. + * The block layer guarantees 'offset' and 'bytes' are within bounds. * - * 'pnum' is set to the number of sectors (including and immediately follo= wing - * the specified sector) that are known to be in the same + * 'pnum' is set to the number of bytes (including and immediately followi= ng + * the specified offset) that are known to be in the same * allocated/unallocated state. * - * '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. + * 'bytes' is the max value 'pnum' should be set to. */ -static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs, - int64_t sector_num, - int nb_sectors, int *p= num, - BlockDriverState **fil= e) -{ - off_t start, data =3D 0, hole =3D 0; - int64_t total_size; +static int coroutine_fn raw_co_block_status(BlockDriverState *bs, + bool want_zero, + int64_t offset, + int64_t bytes, int64_t *pnum, + int64_t *map, + BlockDriverState **file) +{ + off_t data =3D 0, hole =3D 0; int ret; =20 ret =3D fd_open(bs); @@ -2157,39 +2156,36 @@ static int64_t coroutine_fn raw_co_get_block_status= (BlockDriverState *bs, return ret; } =20 - start =3D sector_num * BDRV_SECTOR_SIZE; - total_size =3D bdrv_getlength(bs); - if (total_size < 0) { - return total_size; - } else if (start >=3D total_size) { - *pnum =3D 0; - return 0; - } else if (start + nb_sectors * BDRV_SECTOR_SIZE > total_size) { - nb_sectors =3D DIV_ROUND_UP(total_size - start, BDRV_SECTOR_SIZE); + if (!want_zero) { + *pnum =3D bytes; + *map =3D offset; + *file =3D bs; + return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; } =20 - ret =3D find_allocation(bs, start, &data, &hole); + ret =3D find_allocation(bs, offset, &data, &hole); if (ret =3D=3D -ENXIO) { /* Trailing hole */ - *pnum =3D nb_sectors; + *pnum =3D bytes; ret =3D BDRV_BLOCK_ZERO; } else if (ret < 0) { /* No info available, so pretend there are no holes */ - *pnum =3D nb_sectors; + *pnum =3D bytes; ret =3D BDRV_BLOCK_DATA; - } else if (data =3D=3D start) { - /* On a data extent, compute sectors to the end of the extent, + } else if (data =3D=3D offset) { + /* On a data extent, compute bytes to the end of the extent, * possibly including a partial sector at EOF. */ - *pnum =3D MIN(nb_sectors, DIV_ROUND_UP(hole - start, BDRV_SECTOR_S= IZE)); + *pnum =3D MIN(bytes, hole - offset); ret =3D BDRV_BLOCK_DATA; } else { - /* On a hole, compute sectors to the beginning of the next extent.= */ - assert(hole =3D=3D start); - *pnum =3D MIN(nb_sectors, (data - start) / BDRV_SECTOR_SIZE); + /* On a hole, compute bytes to the beginning of the next extent. = */ + assert(hole =3D=3D offset); + *pnum =3D MIN(bytes, data - offset); ret =3D BDRV_BLOCK_ZERO; } + *map =3D offset; *file =3D bs; - return ret | BDRV_BLOCK_OFFSET_VALID | start; + return ret | BDRV_BLOCK_OFFSET_VALID; } =20 static coroutine_fn BlockAIOCB *raw_aio_pdiscard(BlockDriverState *bs, @@ -2282,7 +2278,7 @@ BlockDriver bdrv_file =3D { .bdrv_close =3D raw_close, .bdrv_create =3D raw_create, .bdrv_has_zero_init =3D bdrv_has_zero_init_1, - .bdrv_co_get_block_status =3D raw_co_get_block_status, + .bdrv_co_block_status =3D raw_co_block_status, .bdrv_co_pwrite_zeroes =3D raw_co_pwrite_zeroes, =20 .bdrv_co_preadv =3D raw_co_preadv, --=20 2.13.6