From patchwork Wed Sep 30 09:46:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: cenjiahui X-Patchwork-Id: 304061 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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 176C8C4727E for ; Wed, 30 Sep 2020 09:52:31 +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 8CB2E2075F for ; Wed, 30 Sep 2020 09:52:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8CB2E2075F 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]:32978 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kNYmj-0004gU-Mp for qemu-devel@archiver.kernel.org; Wed, 30 Sep 2020 05:52:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37554) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kNYhR-00072z-W0 for qemu-devel@nongnu.org; Wed, 30 Sep 2020 05:47:02 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:38748 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 1kNYhM-0003oQ-TJ for qemu-devel@nongnu.org; Wed, 30 Sep 2020 05:47:01 -0400 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 1AF423D944E5AF00A8BE; Wed, 30 Sep 2020 17:46:54 +0800 (CST) Received: from localhost (10.174.186.107) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.487.0; Wed, 30 Sep 2020 17:46:43 +0800 From: Jiahui Cen To: Subject: [RFC PATCH v2 3/8] block-backend: add I/O hang timeout Date: Wed, 30 Sep 2020 17:46:01 +0800 Message-ID: <20200930094606.5323-4-cenjiahui@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200930094606.5323-1-cenjiahui@huawei.com> References: <20200930094606.5323-1-cenjiahui@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.186.107] X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.32; envelope-from=cenjiahui@huawei.com; helo=huawei.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/30 05:46:49 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, 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, fangying1@huawei.com, cenjiahui@huawei.com, zhang.zhanghailiang@huawei.com, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Not all errors would be fixed, so it is better to add a rehandle timeout for I/O hang. Signed-off-by: Jiahui Cen Signed-off-by: Ying Fang --- block/block-backend.c | 99 +++++++++++++++++++++++++++++++++- include/sysemu/block-backend.h | 2 + 2 files changed, 100 insertions(+), 1 deletion(-) diff --git a/block/block-backend.c b/block/block-backend.c index 8050669d23..90fcc678b5 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -38,6 +38,11 @@ static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb); /* block backend rehandle timer interval 5s */ #define BLOCK_BACKEND_REHANDLE_TIMER_INTERVAL 5000 +enum BlockIOHangStatus { + BLOCK_IO_HANG_STATUS_NORMAL = 0, + BLOCK_IO_HANG_STATUS_HANG, +}; + typedef struct BlockBackendRehandleInfo { bool enable; QEMUTimer *ts; @@ -109,6 +114,11 @@ struct BlockBackend { unsigned int in_flight; BlockBackendRehandleInfo reinfo; + + int64_t iohang_timeout; /* The I/O hang timeout value in sec. */ + int64_t iohang_time; /* The I/O hang start time */ + bool is_iohang_timeout; + int iohang_status; }; typedef struct BlockBackendAIOCB { @@ -2481,20 +2491,107 @@ static void blk_rehandle_timer_cb(void *opaque) aio_context_release(blk_get_aio_context(blk)); } +static bool blk_iohang_handle(BlockBackend *blk, int new_status) +{ + int64_t now; + int old_status = blk->iohang_status; + bool need_rehandle = false; + + switch (new_status) { + case BLOCK_IO_HANG_STATUS_NORMAL: + if (old_status == BLOCK_IO_HANG_STATUS_HANG) { + /* Case when I/O Hang is recovered */ + blk->is_iohang_timeout = false; + blk->iohang_time = 0; + } + break; + case BLOCK_IO_HANG_STATUS_HANG: + if (old_status != BLOCK_IO_HANG_STATUS_HANG) { + /* Case when I/O hang is first triggered */ + blk->iohang_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000; + need_rehandle = true; + } else { + if (!blk->is_iohang_timeout) { + now = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000; + if (now >= (blk->iohang_time + blk->iohang_timeout)) { + /* Case when I/O hang is timeout */ + blk->is_iohang_timeout = true; + } else { + /* Case when I/O hang is continued */ + need_rehandle = true; + } + } + } + break; + default: + break; + } + + blk->iohang_status = new_status; + return need_rehandle; +} + +static bool blk_rehandle_aio(BlkAioEmAIOCB *acb, bool *has_timeout) +{ + bool need_rehandle = false; + + /* Rehandle aio which returns EIO before hang timeout */ + if (acb->rwco.ret == -EIO) { + if (acb->rwco.blk->is_iohang_timeout) { + /* I/O hang has timeout and not recovered */ + *has_timeout = true; + } else { + need_rehandle = blk_iohang_handle(acb->rwco.blk, + BLOCK_IO_HANG_STATUS_HANG); + /* I/O hang timeout first trigger */ + if (acb->rwco.blk->is_iohang_timeout) { + *has_timeout = true; + } + } + } + + return need_rehandle; +} + static void blk_rehandle_aio_complete(BlkAioEmAIOCB *acb) { + bool has_timeout = false; + bool need_rehandle = false; + if (acb->has_returned) { blk_dec_in_flight(acb->rwco.blk); - if (acb->rwco.ret == -EIO) { + 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); + + /* I/O hang return to normal status */ + if (!has_timeout) { + blk_iohang_handle(acb->rwco.blk, BLOCK_IO_HANG_STATUS_NORMAL); + } + qemu_aio_unref(acb); } } +void blk_iohang_init(BlockBackend *blk, int64_t iohang_timeout) +{ + if (!blk) { + return; + } + + blk->is_iohang_timeout = false; + blk->iohang_time = 0; + blk->iohang_timeout = 0; + blk->iohang_status = BLOCK_IO_HANG_STATUS_NORMAL; + if (iohang_timeout > 0) { + blk->iohang_timeout = iohang_timeout; + } +} + void blk_register_buf(BlockBackend *blk, void *host, size_t size) { bdrv_register_buf(blk_bs(blk), host, size); diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 8203d7f6f9..bfebe3a960 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -268,4 +268,6 @@ const BdrvChild *blk_root(BlockBackend *blk); int blk_make_empty(BlockBackend *blk, Error **errp); +void blk_iohang_init(BlockBackend *blk, int64_t iohang_timeout); + #endif