From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07A14C4741F for ; Sun, 27 Sep 2020 13:06:48 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 82916239A1 for ; Sun, 27 Sep 2020 13:06:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82916239A1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56506 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kMWO6-0001F8-HF for qemu-devel@archiver.kernel.org; Sun, 27 Sep 2020 09:06:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60858) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kMWMS-0007qe-5d for qemu-devel@nongnu.org; Sun, 27 Sep 2020 09:05:04 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:40272 helo=huawei.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kMWMQ-0003Mz-1H for qemu-devel@nongnu.org; Sun, 27 Sep 2020 09:05:03 -0400 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id AFA9BD578B7977E05671; Sun, 27 Sep 2020 21:04:47 +0800 (CST) Received: from localhost (10.174.185.104) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.487.0; Sun, 27 Sep 2020 21:04:41 +0800 From: Ying Fang To: Subject: [RFC PATCH 4/7] block-backend: add I/O hang drain when disbale Date: Sun, 27 Sep 2020 21:04:17 +0800 Message-ID: <20200927130420.1095-5-fangying1@huawei.com> X-Mailer: git-send-email 2.28.0.windows.1 In-Reply-To: <20200927130420.1095-1-fangying1@huawei.com> References: <20200927130420.1095-1-fangying1@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.174.185.104] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.35; envelope-from=fangying1@huawei.com; helo=huawei.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/27 09:04:48 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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, Ying Fang , Jiahui Cen , zhang.zhanghailiang@huawei.com, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" To disable I/O hang, all hanging AIOs need to be drained. A rehandle status field is introduced to notify rehandle mechanism not to rehandle failed AIOs when I/O hang is disabled. Signed-off-by: Ying Fang Signed-off-by: Jiahui Cen --- block/block-backend.c | 85 ++++++++++++++++++++++++++++++++-- include/sysemu/block-backend.h | 3 ++ 2 files changed, 84 insertions(+), 4 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index d0b2b59f55..95b2d6a679 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -37,6 +37,9 @@ static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb); /* block backend rehandle timer interval 5s */ #define BLOCK_BACKEND_REHANDLE_TIMER_INTERVAL 5000 +#define BLOCK_BACKEND_REHANDLE_NORMAL 1 +#define BLOCK_BACKEND_REHANDLE_DRAIN_REQUESTED 2 +#define BLOCK_BACKEND_REHANDLE_DRAINED 3 enum BlockIOHangStatus { BLOCK_IO_HANG_STATUS_NORMAL = 0, @@ -50,6 +53,8 @@ typedef struct BlockBackendRehandleInfo { unsigned int in_flight; QTAILQ_HEAD(, BlkAioEmAIOCB) re_aios; + + int status; } BlockBackendRehandleInfo; typedef struct BlockBackendAioNotifier { @@ -471,6 +476,8 @@ static void blk_delete(BlockBackend *blk) assert(!blk->refcnt); assert(!blk->name); assert(!blk->dev); + assert(atomic_read(&blk->reinfo.in_flight) == 0); + blk_rehandle_disable(blk); if (blk->public.throttle_group_member.throttle_state) { blk_io_limits_disable(blk); } @@ -2460,6 +2467,37 @@ static void blk_rehandle_remove_aiocb(BlockBackend *blk, BlkAioEmAIOCB *acb) atomic_dec(&blk->reinfo.in_flight); } +static void blk_rehandle_drain(BlockBackend *blk) +{ + if (blk_bs(blk)) { + bdrv_drained_begin(blk_bs(blk)); + BDRV_POLL_WHILE(blk_bs(blk), atomic_read(&blk->reinfo.in_flight) > 0); + bdrv_drained_end(blk_bs(blk)); + } +} + +static bool blk_rehandle_is_paused(BlockBackend *blk) +{ + return blk->reinfo.status == BLOCK_BACKEND_REHANDLE_DRAIN_REQUESTED || + blk->reinfo.status == BLOCK_BACKEND_REHANDLE_DRAINED; +} + +static void blk_rehandle_pause(BlockBackend *blk) +{ + BlockBackendRehandleInfo *reinfo = &blk->reinfo; + + aio_context_acquire(blk_get_aio_context(blk)); + if (!reinfo->enable || reinfo->status == BLOCK_BACKEND_REHANDLE_DRAINED) { + aio_context_release(blk_get_aio_context(blk)); + return; + } + + reinfo->status = BLOCK_BACKEND_REHANDLE_DRAIN_REQUESTED; + blk_rehandle_drain(blk); + reinfo->status = BLOCK_BACKEND_REHANDLE_DRAINED; + aio_context_release(blk_get_aio_context(blk)); +} + static void blk_rehandle_timer_cb(void *opaque) { BlockBackend *blk = opaque; @@ -2559,10 +2597,12 @@ static void blk_rehandle_aio_complete(BlkAioEmAIOCB *acb) if (acb->has_returned) { blk_dec_in_flight(acb->rwco.blk); - need_rehandle = blk_rehandle_aio(acb, &has_timeout); - if (need_rehandle) { - blk_rehandle_insert_aiocb(acb->rwco.blk, acb); - return; + if (!blk_rehandle_is_paused(acb->rwco.blk)) { + need_rehandle = blk_rehandle_aio(acb, &has_timeout); + if (need_rehandle) { + blk_rehandle_insert_aiocb(acb->rwco.blk, acb); + return; + } } acb->common.cb(acb->common.opaque, acb->rwco.ret); @@ -2576,6 +2616,42 @@ static void blk_rehandle_aio_complete(BlkAioEmAIOCB *acb) } } +void blk_rehandle_enable(BlockBackend *blk) +{ + BlockBackendRehandleInfo *reinfo = &blk->reinfo; + + aio_context_acquire(blk_get_aio_context(blk)); + if (reinfo->enable) { + aio_context_release(blk_get_aio_context(blk)); + return; + } + + reinfo->ts = aio_timer_new(blk_get_aio_context(blk), QEMU_CLOCK_REALTIME, + SCALE_MS, blk_rehandle_timer_cb, blk); + reinfo->timer_interval_ms = BLOCK_BACKEND_REHANDLE_TIMER_INTERVAL; + reinfo->status = BLOCK_BACKEND_REHANDLE_NORMAL; + reinfo->enable = true; + aio_context_release(blk_get_aio_context(blk)); +} + +void blk_rehandle_disable(BlockBackend *blk) +{ + if (!blk->reinfo.enable) { + return; + } + + blk_rehandle_pause(blk); + timer_del(blk->reinfo.ts); + timer_free(blk->reinfo.ts); + blk->reinfo.ts = NULL; + blk->reinfo.enable = false; +} + +bool blk_iohang_is_enabled(BlockBackend *blk) +{ + return blk->iohang_timeout != 0; +} + void blk_iohang_init(BlockBackend *blk, int64_t iohang_timeout) { if (!blk) { @@ -2588,6 +2664,7 @@ void blk_iohang_init(BlockBackend *blk, int64_t iohang_timeout) blk->iohang_status = BLOCK_IO_HANG_STATUS_NORMAL; if (iohang_timeout > 0) { blk->iohang_timeout = iohang_timeout; + blk_rehandle_enable(blk); } } diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index bfebe3a960..375ae13b0b 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -268,6 +268,9 @@ const BdrvChild *blk_root(BlockBackend *blk); int blk_make_empty(BlockBackend *blk, Error **errp); +void blk_rehandle_enable(BlockBackend *blk); +void blk_rehandle_disable(BlockBackend *blk); +bool blk_iohang_is_enabled(BlockBackend *blk); void blk_iohang_init(BlockBackend *blk, int64_t iohang_timeout); #endif -- 2.23.0