From nobody Wed Apr 2 14:37:53 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1742541120; cv=none; d=zohomail.com; s=zohoarc; b=G4dHMDkT340Zu37HFqq8L11P927e0RpXDWMagmAqP1e77ejL3FnW644c5lOtGH27vp+7muupFJpIb/Gele8ZjqtGFVsHVEZ42FQ2UrHFomDObdcg5TURMOdH2C7eZZWhODYJhFgncm4F8/LfEDKNr6BapY2+t9a9Q4B6Ys5X/Nk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1742541120; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Reply-To:Reply-To:References:Sender:Subject:Subject:To:To:Message-Id; bh=QP0JCN3Sf7+RiENNVtu4VQ/QrcevMv+g+cv2UJ5lXDg=; b=HNcKtSokAzwQww2l4zmEz/Pe9/dmQan5eM/s5+lzZAu7MQlkJrHtSJIDzbmgCyFaGO+W6UNAGb8cWXvMWq0/9CgGpDIzYPanPwYvfO9icv6tilJKlzbZRKGbTVGejKP4KsiO5fILu+DHEFqr3WbdoM0I5OUvXGnqUvhFYc0EHOs= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1742541120358839.7144974453163; Fri, 21 Mar 2025 00:12:00 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tvWX8-0003Ne-66; Fri, 21 Mar 2025 03:11:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tvWX0-0003MX-6G; Fri, 21 Mar 2025 03:11:02 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tvWWw-00085R-8B; Fri, 21 Mar 2025 03:11:01 -0400 Received: from mail.maildlp.com (unknown [172.19.88.163]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4ZJtlT1V9wz1f1L5; Fri, 21 Mar 2025 15:06:13 +0800 (CST) Received: from kwepemk500007.china.huawei.com (unknown [7.202.194.92]) by mail.maildlp.com (Postfix) with ESMTPS id A00AE1800B1; Fri, 21 Mar 2025 15:10:46 +0800 (CST) Received: from huawei.com (10.246.99.19) by kwepemk500007.china.huawei.com (7.202.194.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 21 Mar 2025 15:10:45 +0800 To: CC: , , , , , , , , , , , , , , , , , Subject: [PATCH v2 1/2] io/block: Refactoring the bdrv_drained_begin() function and implement a timeout mechanism. Date: Fri, 21 Mar 2025 15:09:16 +0800 Message-ID: <20250321070917.2889854-2-zoudongjie@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20250321070917.2889854-1-zoudongjie@huawei.com> References: <20250321070917.2889854-1-zoudongjie@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.246.99.19] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemk500007.china.huawei.com (7.202.194.92) Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=45.249.212.35; envelope-from=zoudongjie@huawei.com; helo=szxga07-in.huawei.com 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_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: zoudongjie From: zoudongjie via Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1742541121444019000 Content-Type: text/plain; charset="utf-8" From: Zhu Yangyang The bdrv_drained_begin() function is a blocking function. In scenarios wher= e network storage is used and network links fail, it may block for a long time. Therefore, we add a timeout parameter to control the duration of the block. Since bdrv_drained_begin() has been widely adopted, both bdrv_drained_begin= () and bdrv_drained_begin_timeout() will be retained. Signed-off-by: Zhu Yangyang --- block/io.c | 58 +++++++++++++++++++++++++++++++++------- include/block/aio-wait.h | 49 +++++++++++++++++++++++++++++++++ include/block/block-io.h | 22 ++++++++++++++- util/aio-wait.c | 5 ++++ 4 files changed, 123 insertions(+), 11 deletions(-) diff --git a/block/io.c b/block/io.c index 1ba8d1aeea..912b76c4a4 100644 --- a/block/io.c +++ b/block/io.c @@ -255,6 +255,8 @@ typedef struct { bool begin; bool poll; BdrvChild *parent; + uint64_t timeout_ns; + int ret; } BdrvCoDrainData; =20 /* Returns true if BDRV_POLL_WHILE() should go into a blocking aio_poll() = */ @@ -283,6 +285,10 @@ static bool bdrv_drain_poll_top_level(BlockDriverState= *bs, return bdrv_drain_poll(bs, ignore_parent, false); } =20 +static int bdrv_do_drained_begin_timeout(BlockDriverState *bs, + BdrvChild *parent, + bool poll, + uint64_t timeout_ns); static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent, bool poll); static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent); @@ -296,7 +302,9 @@ static void bdrv_co_drain_bh_cb(void *opaque) if (bs) { bdrv_dec_in_flight(bs); if (data->begin) { - bdrv_do_drained_begin(bs, data->parent, data->poll); + data->ret =3D bdrv_do_drained_begin_timeout(bs, data->parent, + data->poll, + data->timeout_ns); } else { assert(!data->poll); bdrv_do_drained_end(bs, data->parent); @@ -310,10 +318,11 @@ static void bdrv_co_drain_bh_cb(void *opaque) aio_co_wake(co); } =20 -static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, - bool begin, - BdrvChild *parent, - bool poll) +static int coroutine_fn bdrv_co_yield_to_drain_timeout(BlockDriverState *b= s, + bool begin, + BdrvChild *parent, + bool poll, + uint64_t timeout_ns) { BdrvCoDrainData data; Coroutine *self =3D qemu_coroutine_self(); @@ -329,6 +338,8 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDr= iverState *bs, .begin =3D begin, .parent =3D parent, .poll =3D poll, + .timeout_ns =3D timeout_ns, + .ret =3D 0 }; =20 if (bs) { @@ -342,16 +353,27 @@ static void coroutine_fn bdrv_co_yield_to_drain(Block= DriverState *bs, /* If we are resumed from some other event (such as an aio completion = or a * timer callback), it is a bug in the caller that should be fixed. */ assert(data.done); + return data.ret; } =20 -static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent, - bool poll) +static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, + bool begin, + BdrvChild *parent, + bool poll) +{ + bdrv_co_yield_to_drain_timeout(bs, begin, parent, poll, 0); +} + +static int bdrv_do_drained_begin_timeout(BlockDriverState *bs, + BdrvChild *parent, + bool poll, + uint64_t timeout_ns) { IO_OR_GS_CODE(); =20 if (qemu_in_coroutine()) { - bdrv_co_yield_to_drain(bs, true, parent, poll); - return; + return bdrv_co_yield_to_drain_timeout(bs, true, parent, poll, + timeout_ns); } =20 GLOBAL_STATE_CODE(); @@ -375,8 +397,17 @@ static void bdrv_do_drained_begin(BlockDriverState *bs= , BdrvChild *parent, * nodes. */ if (poll) { - BDRV_POLL_WHILE(bs, bdrv_drain_poll_top_level(bs, parent)); + return BDRV_POLL_WHILE_TIMEOUT(bs, + bdrv_drain_poll_top_level(bs, paren= t), + timeout_ns); } + return 0; +} + +static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent, + bool poll) +{ + bdrv_do_drained_begin_timeout(bs, parent, poll, 0); } =20 void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, BdrvChild *parent) @@ -391,6 +422,13 @@ bdrv_drained_begin(BlockDriverState *bs) bdrv_do_drained_begin(bs, NULL, true); } =20 +int coroutine_mixed_fn +bdrv_drained_begin_timeout(BlockDriverState *bs, uint64_t timeout_ns) +{ + IO_OR_GS_CODE(); + return bdrv_do_drained_begin_timeout(bs, NULL, true, timeout_ns); +} + /** * This function does not poll, nor must any of its recursively called * functions. diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h index cf5e8bde1c..24c31df620 100644 --- a/include/block/aio-wait.h +++ b/include/block/aio-wait.h @@ -99,6 +99,53 @@ extern AioWait global_aio_wait; qatomic_dec(&wait_->num_waiters); \ waited_; }) =20 +/** + * AIO_WAIT_WHILE_TIMEOUT: + * + * Refer to the implementation of AIO_WAIT_WHILE_INTERNAL, + * the timeout parameter is added. + * @timeout_ns: maximum duration to wait, in nanoseconds, except the value + * is unsigned, 0 means infinite. + */ +#define AIO_WAIT_WHILE_TIMEOUT(ctx, cond, timeout_ns) ({ \ + int ret_ =3D 0; = \ + uint64_t timeout_ =3D (timeout_ns); = \ + AioWait *wait_ =3D &global_aio_wait; = \ + AioContext *ctx_ =3D (ctx); = \ + AioContext *current_ctx_ =3D NULL; = \ + QEMUTimer timer_; \ + /* Increment wait_->num_waiters before evaluating cond. */ \ + qatomic_inc(&wait_->num_waiters); \ + /* Paired with smp_mb in aio_wait_kick(). */ \ + smp_mb__after_rmw(); \ + if (ctx_ && in_aio_context_home_thread(ctx_)) { \ + current_ctx_ =3D ctx_; = \ + } else { \ + assert(qemu_get_current_aio_context() =3D=3D = \ + qemu_get_aio_context()); \ + current_ctx_ =3D qemu_get_aio_context(); = \ + } \ + if (timeout_ > 0) { \ + timer_init_full(&timer_, ¤t_ctx_->tlg, \ + QEMU_CLOCK_REALTIME, \ + SCALE_NS, 0, aio_wait_timer_cb, NULL); \ + timer_mod_ns(&timer_, \ + qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + \ + timeout_); \ + } \ + while ((cond)) { \ + aio_poll(current_ctx_, true); \ + if (timeout_ > 0 && !timer_pending(&timer_)) { \ + ret_ =3D -ETIMEDOUT; = \ + break; \ + } \ + } \ + if (timeout_ > 0) { \ + timer_del(&timer_); \ + } \ + qatomic_dec(&wait_->num_waiters); \ + ret_; }) + #define AIO_WAIT_WHILE(ctx, cond) \ AIO_WAIT_WHILE_INTERNAL(ctx, cond) =20 @@ -149,4 +196,6 @@ static inline bool in_aio_context_home_thread(AioContex= t *ctx) } } =20 +void aio_wait_timer_cb(void *opaque); + #endif /* QEMU_AIO_WAIT_H */ diff --git a/include/block/block-io.h b/include/block/block-io.h index b49e0537dd..844e9cf350 100644 --- a/include/block/block-io.h +++ b/include/block/block-io.h @@ -354,6 +354,11 @@ bdrv_co_copy_range(BdrvChild *src, int64_t src_offset, AIO_WAIT_WHILE(bdrv_get_aio_context(bs_), \ cond); }) =20 +#define BDRV_POLL_WHILE_TIMEOUT(bs, cond, timeout_ns) ({ \ + BlockDriverState *bs_ =3D (bs); \ + AIO_WAIT_WHILE_TIMEOUT(bdrv_get_aio_context(bs_), \ + cond, timeout_ns); }) + void bdrv_drain(BlockDriverState *bs); =20 int co_wrapper_mixed_bdrv_rdlock @@ -432,7 +437,22 @@ bdrv_drain_poll(BlockDriverState *bs, BdrvChild *ignor= e_parent, void bdrv_drained_begin(BlockDriverState *bs); =20 /** - * bdrv_do_drained_begin_quiesce: + * bdrv_drained_begin_timeout: + * + * Added timeout parameter for bdrv_drained_begin() to make a time limited. + * + * @timeout_ns: maximum duration to wait; 0 means infinite, equal to call + * bdrv_drained_begin(). + * + * Returns: 0 if succeeded; -ETIMEDOUT when a timeout occurs. + * + * Note: when the timeout fails, we've already begin aquiesced section, so= we + * still need to call bdrv_drained_end() to end the quiescent section. + */ +int bdrv_drained_begin_timeout(BlockDriverState *bs, uint64_t timeout_ns); + +/** + * bdrv_do_drained_badegin_quiesce: * * Quiesces a BDS like bdrv_drained_begin(), but does not wait for already * running requests to complete. diff --git a/util/aio-wait.c b/util/aio-wait.c index b5336cf5fd..64c3714fb8 100644 --- a/util/aio-wait.c +++ b/util/aio-wait.c @@ -84,3 +84,8 @@ void aio_wait_bh_oneshot(AioContext *ctx, QEMUBHFunc *cb,= void *opaque) aio_bh_schedule_oneshot(ctx, aio_wait_bh, &data); AIO_WAIT_WHILE_UNLOCKED(NULL, !data.done); } + +void aio_wait_timer_cb(void *opaque) +{ + /* The point is to make AIO_WAIT_WHILE_TIMEOUT()'s aio_poll() return */ +} --=20 2.33.0