From patchwork Tue Jun 14 21:30:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 9176997 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 49B77604DB for ; Tue, 14 Jun 2016 21:44:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3088728334 for ; Tue, 14 Jun 2016 21:44:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 252D128339; Tue, 14 Jun 2016 21:44:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 87F4D28334 for ; Tue, 14 Jun 2016 21:44:14 +0000 (UTC) Received: from localhost ([::1]:38362 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bCw85-0002zU-7v for patchwork-qemu-devel@patchwork.kernel.org; Tue, 14 Jun 2016 17:44:13 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58427) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bCvvX-0007DO-Uw for qemu-devel@nongnu.org; Tue, 14 Jun 2016 17:31:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bCvvQ-0006uk-RM for qemu-devel@nongnu.org; Tue, 14 Jun 2016 17:31:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34017) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bCvvL-0006qx-PI; Tue, 14 Jun 2016 17:31:03 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (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 49B6A80F6D; Tue, 14 Jun 2016 21:31:03 +0000 (UTC) Received: from red.redhat.com (ovpn-116-106.phx2.redhat.com [10.3.116.106]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u5ELUl7N019211; Tue, 14 Jun 2016 17:31:02 -0400 From: Eric Blake To: qemu-devel@nongnu.org Date: Tue, 14 Jun 2016 15:30:37 -0600 Message-Id: <1465939839-30097-16-git-send-email-eblake@redhat.com> In-Reply-To: <1465939839-30097-1-git-send-email-eblake@redhat.com> References: <1465939839-30097-1-git-send-email-eblake@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 14 Jun 2016 21:31:03 +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 v2 15/17] block: Switch discard length bounds 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, Peter Lieven , Max Reitz , Ronnie Sahlberg , Paolo Bonzini Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Sector-based limits are awkward to think about; in our on-going quest to move to byte-based interfaces, convert max_discard and discard_alignment. Rename them, using 'pdiscard' as an aid to track which remaining discard interfaces need conversion, and so that the compiler will help us catch the change in semantics across any rebased code. In iscsi.c, sector_limits_lun2qemu() is no longer needed; and the BlockLimits type is now completely byte-based. Signed-off-by: Eric Blake Reviewed-by: Fam Zheng --- v2: rebase nbd and iscsi limits across earlier improvements --- include/block/block_int.h | 21 +++++++++++++++------ block/io.c | 16 +++++++++------- block/iscsi.c | 19 ++++++------------- block/nbd.c | 2 +- qemu-img.c | 3 ++- 5 files changed, 33 insertions(+), 28 deletions(-) diff --git a/include/block/block_int.h b/include/block/block_int.h index 2b45d57..0169019 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -324,18 +324,27 @@ struct BlockDriver { }; typedef struct BlockLimits { - /* maximum number of sectors that can be discarded at once */ - int max_discard; + /* maximum number of bytes that can be discarded at once (since it + * is signed, it must be < 2G, if set), should be multiple of + * pdiscard_alignment, but need not be power of 2. May be 0 if no + * inherent 32-bit limit */ + int32_t max_pdiscard; - /* optimal alignment for discard requests in sectors */ - int64_t discard_alignment; + /* optimal alignment for discard requests in bytes, must be power + * of 2, less than max_discard if that is set, and multiple of + * bs->request_alignment. May be 0 if bs->request_alignment is + * good enough */ + uint32_t pdiscard_alignment; /* maximum number of bytes that can zeroized at once (since it is - * signed, it must be < 2G, if set) */ + * signed, it must be < 2G, if set), should be multiple of + * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */ int32_t max_pwrite_zeroes; /* optimal alignment for write zeroes requests in bytes, must be - * power of 2, and less than max_pwrite_zeroes if that is set */ + * power of 2, less than max_pwrite_zeroes if that is set, and + * multiple of bs->request_alignment. May be 0 if + * bs->request_alignment is good enough */ uint32_t pwrite_zeroes_alignment; /* optimal transfer length in bytes (must be power of 2, and diff --git a/block/io.c b/block/io.c index 5e38ab4..0b5c40d 100644 --- a/block/io.c +++ b/block/io.c @@ -2352,19 +2352,21 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, BDRV_TRACKED_DISCARD); bdrv_set_dirty(bs, sector_num, nb_sectors); - max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS); + max_discard = MIN_NON_ZERO(bs->bl.max_pdiscard >> BDRV_SECTOR_BITS, + BDRV_REQUEST_MAX_SECTORS); while (nb_sectors > 0) { int ret; int num = nb_sectors; + int discard_alignment = bs->bl.pdiscard_alignment >> BDRV_SECTOR_BITS; /* align request */ - if (bs->bl.discard_alignment && - num >= bs->bl.discard_alignment && - sector_num % bs->bl.discard_alignment) { - if (num > bs->bl.discard_alignment) { - num = bs->bl.discard_alignment; + if (discard_alignment && + num >= discard_alignment && + sector_num % discard_alignment) { + if (num > discard_alignment) { + num = discard_alignment; } - num -= sector_num % bs->bl.discard_alignment; + num -= sector_num % discard_alignment; } /* limit request size */ diff --git a/block/iscsi.c b/block/iscsi.c index 739d5ca..af9babf 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -1696,13 +1696,6 @@ static void iscsi_close(BlockDriverState *bs) memset(iscsilun, 0, sizeof(IscsiLun)); } -static int sector_limits_lun2qemu(int64_t sector, IscsiLun *iscsilun) -{ - int limit = MIN(sector_lun2qemu(sector, iscsilun), INT_MAX / 2 + 1); - - return limit < BDRV_REQUEST_MAX_SECTORS ? limit : 0; -} - static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp) { /* We don't actually refresh here, but just return data queried in @@ -1722,14 +1715,14 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp) } if (iscsilun->lbp.lbpu) { - if (iscsilun->bl.max_unmap < 0xffffffff) { - bs->bl.max_discard = - sector_limits_lun2qemu(iscsilun->bl.max_unmap, iscsilun); + if (iscsilun->bl.max_unmap < 0xffffffff / iscsilun->block_size) { + bs->bl.max_pdiscard = + iscsilun->bl.max_unmap * iscsilun->block_size; } - bs->bl.discard_alignment = - sector_limits_lun2qemu(iscsilun->bl.opt_unmap_gran, iscsilun); + bs->bl.pdiscard_alignment = + iscsilun->bl.opt_unmap_gran * iscsilun->block_size; } else { - bs->bl.discard_alignment = iscsilun->block_size >> BDRV_SECTOR_BITS; + bs->bl.pdiscard_alignment = iscsilun->block_size; } if (iscsilun->bl.max_ws_len < 0xffffffff / iscsilun->block_size) { diff --git a/block/nbd.c b/block/nbd.c index f5511ea..08e5b67 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -362,7 +362,7 @@ static int nbd_co_flush(BlockDriverState *bs) static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) { - bs->bl.max_discard = NBD_MAX_SECTORS; + bs->bl.max_pdiscard = NBD_MAX_BUFFER_SIZE; bs->bl.max_transfer = NBD_MAX_BUFFER_SIZE; } diff --git a/qemu-img.c b/qemu-img.c index cf9876d..1237d61 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -2084,7 +2084,8 @@ static int img_convert(int argc, char **argv) bufsectors = MIN(32768, MAX(bufsectors, MAX(out_bs->bl.opt_transfer >> BDRV_SECTOR_BITS, - out_bs->bl.discard_alignment))); + out_bs->bl.pdiscard_alignment >> + BDRV_SECTOR_BITS))); if (skip_create) { int64_t output_sectors = blk_nb_sectors(out_blk);