From patchwork Wed Jun 22 15:50:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 639259 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)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rZTqW6d24z9t1K for ; Thu, 23 Jun 2016 02:01:43 +1000 (AEST) Received: from localhost ([::1]:59318 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bFkaz-00043N-Sw for incoming@patchwork.ozlabs.org; Wed, 22 Jun 2016 12:01:41 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48284) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bFkRF-0002Ot-V7 for qemu-devel@nongnu.org; Wed, 22 Jun 2016 11:51:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bFkR8-0002BO-Rb for qemu-devel@nongnu.org; Wed, 22 Jun 2016 11:51:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43115) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bFkQw-000264-7o; Wed, 22 Jun 2016 11:51:18 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AF368C05B1D8; Wed, 22 Jun 2016 15:51:17 +0000 (UTC) Received: from red.redhat.com (ovpn-116-13.phx2.redhat.com [10.3.116.13]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u5MFpGut031046; Wed, 22 Jun 2016 11:51:17 -0400 From: Eric Blake To: qemu-devel@nongnu.org Date: Wed, 22 Jun 2016 09:50:58 -0600 Message-Id: <1466610674-23157-2-git-send-email-eblake@redhat.com> In-Reply-To: <1466610674-23157-1-git-send-email-eblake@redhat.com> References: <1466610674-23157-1-git-send-email-eblake@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 22 Jun 2016 15:51:17 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 01/17] block: Convert bdrv_co_discard() to byte-based 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, Fam Zheng , Stefan Hajnoczi , qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_co_discard() with a new byte-based bdrv_co_pdiscard(), which silently ignores any unaligned head or tail. Driver callbacks will be converted in followup patches. By calculating the alignment outside of the loop, and clamping the max discard to an aligned value, we can simplify the actions done within the loop. Signed-off-by: Eric Blake Reviewed-by: Stefan Hajnoczi --- include/block/block.h | 2 +- block/blkreplay.c | 3 ++- block/block-backend.c | 3 ++- block/io.c | 67 +++++++++++++++++++++++++++------------------------ block/raw_bsd.c | 3 ++- 5 files changed, 42 insertions(+), 36 deletions(-) diff --git a/include/block/block.h b/include/block/block.h index c1d4648..b8df2fb 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -345,7 +345,7 @@ void coroutine_fn bdrv_co_drain(BlockDriverState *bs); void bdrv_drain_all(void); int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors); -int bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors); +int bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, int count); int bdrv_has_zero_init_1(BlockDriverState *bs); int bdrv_has_zero_init(BlockDriverState *bs); bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs); diff --git a/block/blkreplay.c b/block/blkreplay.c index 525c2d5..28024c8 100755 --- a/block/blkreplay.c +++ b/block/blkreplay.c @@ -118,7 +118,8 @@ static int coroutine_fn blkreplay_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { uint64_t reqid = request_id++; - int ret = bdrv_co_discard(bs->file->bs, sector_num, nb_sectors); + int ret = bdrv_co_pdiscard(bs->file->bs, sector_num << BDRV_SECTOR_BITS, + nb_sectors << BDRV_SECTOR_BITS); block_request_create(reqid, bs, qemu_coroutine_self()); qemu_coroutine_yield(); diff --git a/block/block-backend.c b/block/block-backend.c index e042544..f44e7e6 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1108,7 +1108,8 @@ int blk_co_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors) return ret; } - return bdrv_co_discard(blk_bs(blk), sector_num, nb_sectors); + return bdrv_co_pdiscard(blk_bs(blk), sector_num << BDRV_SECTOR_BITS, + nb_sectors << BDRV_SECTOR_BITS); } int blk_co_flush(BlockBackend *blk) diff --git a/block/io.c b/block/io.c index 727a2d4..22869b8 100644 --- a/block/io.c +++ b/block/io.c @@ -2193,7 +2193,8 @@ static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) BlockAIOCBCoroutine *acb = opaque; BlockDriverState *bs = acb->common.bs; - acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); + acb->req.error = bdrv_co_pdiscard(bs, acb->req.sector << BDRV_SECTOR_BITS, + acb->req.nb_sectors << BDRV_SECTOR_BITS); bdrv_co_complete(acb); } @@ -2367,20 +2368,22 @@ static void coroutine_fn bdrv_discard_co_entry(void *opaque) { DiscardCo *rwco = opaque; - rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); + rwco->ret = bdrv_co_pdiscard(rwco->bs, rwco->sector_num << BDRV_SECTOR_BITS, + rwco->nb_sectors << BDRV_SECTOR_BITS); } -int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, - int nb_sectors) +int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, + int count) { BdrvTrackedRequest req; - int max_discard, ret; + int max_pdiscard, ret; + int head, align; if (!bs->drv) { return -ENOMEDIUM; } - ret = bdrv_check_request(bs, sector_num, nb_sectors); + ret = bdrv_check_byte_request(bs, offset, count); if (ret < 0) { return ret; } else if (bs->read_only) { @@ -2397,45 +2400,45 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, return 0; } - tracked_request_begin(&req, bs, sector_num << BDRV_SECTOR_BITS, - nb_sectors << BDRV_SECTOR_BITS, BDRV_TRACKED_DISCARD); + /* Discard is advisory, so ignore any unaligned head or tail */ + align = MAX(BDRV_SECTOR_SIZE, + MAX(bs->bl.pdiscard_alignment, bs->bl.request_alignment)); + assert(is_power_of_2(align)); + head = MIN(count, -offset & (align - 1)); + if (head) { + count -= head; + offset += head; + } + count = QEMU_ALIGN_DOWN(count, align); + if (!count) { + return 0; + } + + tracked_request_begin(&req, bs, offset, count, BDRV_TRACKED_DISCARD); ret = notifier_with_return_list_notify(&bs->before_write_notifiers, &req); if (ret < 0) { goto out; } - max_discard = MIN_NON_ZERO(bs->bl.max_pdiscard >> BDRV_SECTOR_BITS, - BDRV_REQUEST_MAX_SECTORS); - while (nb_sectors > 0) { + max_pdiscard = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_pdiscard, INT_MAX), + align); + + while (count > 0) { int ret; - int num = nb_sectors; - int discard_alignment = bs->bl.pdiscard_alignment >> BDRV_SECTOR_BITS; - - /* align request */ - if (discard_alignment && - num >= discard_alignment && - sector_num % discard_alignment) { - if (num > discard_alignment) { - num = discard_alignment; - } - num -= sector_num % discard_alignment; - } - - /* limit request size */ - if (num > max_discard) { - num = max_discard; - } + int num = MIN(count, max_pdiscard); if (bs->drv->bdrv_co_discard) { - ret = bs->drv->bdrv_co_discard(bs, sector_num, num); + ret = bs->drv->bdrv_co_discard(bs, offset >> BDRV_SECTOR_BITS, + num >> BDRV_SECTOR_BITS); } else { BlockAIOCB *acb; CoroutineIOCompletion co = { .coroutine = qemu_coroutine_self(), }; - acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, + acb = bs->drv->bdrv_aio_discard(bs, offset >> BDRV_SECTOR_BITS, + num >> BDRV_SECTOR_BITS, bdrv_co_io_em_complete, &co); if (acb == NULL) { ret = -EIO; @@ -2449,8 +2452,8 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, goto out; } - sector_num += num; - nb_sectors -= num; + offset += num; + count -= num; } ret = 0; out: diff --git a/block/raw_bsd.c b/block/raw_bsd.c index 47a8352..907172e 100644 --- a/block/raw_bsd.c +++ b/block/raw_bsd.c @@ -137,7 +137,8 @@ static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs, static int coroutine_fn raw_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { - return bdrv_co_discard(bs->file->bs, sector_num, nb_sectors); + return bdrv_co_pdiscard(bs->file->bs, sector_num << BDRV_SECTOR_BITS, + nb_sectors << BDRV_SECTOR_BITS); } static int64_t raw_getlength(BlockDriverState *bs)