From patchwork Fri Jul 19 13:43:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11050163 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 70C94112C for ; Fri, 19 Jul 2019 13:45:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5F00E28635 for ; Fri, 19 Jul 2019 13:45:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5345B2894E; Fri, 19 Jul 2019 13:45:17 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id BF8FC28635 for ; Fri, 19 Jul 2019 13:45:16 +0000 (UTC) Received: from localhost ([::1]:45634 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hoTCF-0008Gt-JZ for patchwork-qemu-devel@patchwork.kernel.org; Fri, 19 Jul 2019 09:45:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40345) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hoTB9-0003TU-JF for qemu-devel@nongnu.org; Fri, 19 Jul 2019 09:44:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hoTB6-0003VL-Id for qemu-devel@nongnu.org; Fri, 19 Jul 2019 09:44:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50408) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hoTB3-0003Sj-CE; Fri, 19 Jul 2019 09:44:01 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AE9D630BD1BB; Fri, 19 Jul 2019 13:44:00 +0000 (UTC) Received: from dhcp-200-226.str.redhat.com (dhcp-200-226.str.redhat.com [10.33.200.226]) by smtp.corp.redhat.com (Postfix) with ESMTP id BDA05608D0; Fri, 19 Jul 2019 13:43:59 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 19 Jul 2019 15:43:36 +0200 Message-Id: <20190719134345.23526-5-kwolf@redhat.com> In-Reply-To: <20190719134345.23526-1-kwolf@redhat.com> References: <20190719134345.23526-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Fri, 19 Jul 2019 13:44:00 +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] [PULL 04/13] block: Add @drained_end_counter X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Max Reitz Callers can now pass a pointer to an integer that bdrv_drain_invoke() (and its recursive callees) will increment for every bdrv_drain_invoke_entry() operation they schedule. bdrv_drain_invoke_entry() in turn will decrement it once it has invoked BlockDriver.bdrv_co_drain_end(). We use atomic operations to access the pointee, because the bdrv_do_drained_end() caller may wish to end drained sections for multiple nodes in different AioContexts (bdrv_drain_all_end() does, for example). This is the first step to moving the polling for BdrvCoDrainData.done to become true out of bdrv_drain_invoke() and into the root drained_end function. Signed-off-by: Max Reitz Signed-off-by: Kevin Wolf --- block/io.c | 58 +++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 40 insertions(+), 18 deletions(-) diff --git a/block/io.c b/block/io.c index 1e618f9a37..c42e18b068 100644 --- a/block/io.c +++ b/block/io.c @@ -194,6 +194,7 @@ typedef struct { bool poll; BdrvChild *parent; bool ignore_bds_parents; + int *drained_end_counter; } BdrvCoDrainData; static void coroutine_fn bdrv_drain_invoke_entry(void *opaque) @@ -211,13 +212,18 @@ static void coroutine_fn bdrv_drain_invoke_entry(void *opaque) atomic_mb_set(&data->done, true); bdrv_dec_in_flight(bs); - if (data->begin) { + if (data->drained_end_counter) { + atomic_dec(data->drained_end_counter); + } + + if (data->begin || data->drained_end_counter) { g_free(data); } } /* Recursively call BlockDriver.bdrv_co_drain_begin/end callbacks */ -static void bdrv_drain_invoke(BlockDriverState *bs, bool begin) +static void bdrv_drain_invoke(BlockDriverState *bs, bool begin, + int *drained_end_counter) { BdrvCoDrainData *data; @@ -230,16 +236,25 @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin) *data = (BdrvCoDrainData) { .bs = bs, .done = false, - .begin = begin + .begin = begin, + .drained_end_counter = drained_end_counter, }; + if (!begin && drained_end_counter) { + atomic_inc(drained_end_counter); + } + /* Make sure the driver callback completes during the polling phase for * drain_begin. */ bdrv_inc_in_flight(bs); data->co = qemu_coroutine_create(bdrv_drain_invoke_entry, data); aio_co_schedule(bdrv_get_aio_context(bs), data->co); - if (!begin) { + /* + * TODO: Drop this and make callers pass @drained_end_counter and poll + * themselves + */ + if (!begin && !drained_end_counter) { BDRV_POLL_WHILE(bs, !data->done); g_free(data); } @@ -281,7 +296,8 @@ static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive, BdrvChild *parent, bool ignore_bds_parents, bool poll); static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, - BdrvChild *parent, bool ignore_bds_parents); + BdrvChild *parent, bool ignore_bds_parents, + int *drained_end_counter); static void bdrv_co_drain_bh_cb(void *opaque) { @@ -308,7 +324,8 @@ static void bdrv_co_drain_bh_cb(void *opaque) data->ignore_bds_parents, data->poll); } else { bdrv_do_drained_end(bs, data->recursive, data->parent, - data->ignore_bds_parents); + data->ignore_bds_parents, + data->drained_end_counter); } if (ctx == co_ctx) { aio_context_release(ctx); @@ -326,7 +343,8 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, bool begin, bool recursive, BdrvChild *parent, bool ignore_bds_parents, - bool poll) + bool poll, + int *drained_end_counter) { BdrvCoDrainData data; @@ -343,7 +361,9 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, .parent = parent, .ignore_bds_parents = ignore_bds_parents, .poll = poll, + .drained_end_counter = drained_end_counter, }; + if (bs) { bdrv_inc_in_flight(bs); } @@ -367,7 +387,7 @@ void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, } bdrv_parent_drained_begin(bs, parent, ignore_bds_parents); - bdrv_drain_invoke(bs, true); + bdrv_drain_invoke(bs, true, NULL); } static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive, @@ -378,7 +398,7 @@ static void bdrv_do_drained_begin(BlockDriverState *bs, bool recursive, if (qemu_in_coroutine()) { bdrv_co_yield_to_drain(bs, true, recursive, parent, ignore_bds_parents, - poll); + poll, NULL); return; } @@ -419,20 +439,21 @@ void bdrv_subtree_drained_begin(BlockDriverState *bs) } static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, - BdrvChild *parent, bool ignore_bds_parents) + BdrvChild *parent, bool ignore_bds_parents, + int *drained_end_counter) { BdrvChild *child, *next; int old_quiesce_counter; if (qemu_in_coroutine()) { bdrv_co_yield_to_drain(bs, false, recursive, parent, ignore_bds_parents, - false); + false, drained_end_counter); return; } assert(bs->quiesce_counter > 0); /* Re-enable things in child-to-parent order */ - bdrv_drain_invoke(bs, false); + bdrv_drain_invoke(bs, false, drained_end_counter); bdrv_parent_drained_end(bs, parent, ignore_bds_parents); old_quiesce_counter = atomic_fetch_dec(&bs->quiesce_counter); @@ -444,19 +465,20 @@ static void bdrv_do_drained_end(BlockDriverState *bs, bool recursive, assert(!ignore_bds_parents); bs->recursive_quiesce_counter--; QLIST_FOREACH_SAFE(child, &bs->children, next, next) { - bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents); + bdrv_do_drained_end(child->bs, true, child, ignore_bds_parents, + drained_end_counter); } } } void bdrv_drained_end(BlockDriverState *bs) { - bdrv_do_drained_end(bs, false, NULL, false); + bdrv_do_drained_end(bs, false, NULL, false, NULL); } void bdrv_subtree_drained_end(BlockDriverState *bs) { - bdrv_do_drained_end(bs, true, NULL, false); + bdrv_do_drained_end(bs, true, NULL, false, NULL); } void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent) @@ -473,7 +495,7 @@ void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent) int i; for (i = 0; i < old_parent->recursive_quiesce_counter; i++) { - bdrv_do_drained_end(child->bs, true, child, false); + bdrv_do_drained_end(child->bs, true, child, false, NULL); } } @@ -543,7 +565,7 @@ void bdrv_drain_all_begin(void) BlockDriverState *bs = NULL; if (qemu_in_coroutine()) { - bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true); + bdrv_co_yield_to_drain(NULL, true, false, NULL, true, true, NULL); return; } @@ -579,7 +601,7 @@ void bdrv_drain_all_end(void) AioContext *aio_context = bdrv_get_aio_context(bs); aio_context_acquire(aio_context); - bdrv_do_drained_end(bs, false, NULL, true); + bdrv_do_drained_end(bs, false, NULL, true, NULL); aio_context_release(aio_context); }