From patchwork Thu May 4 19:53:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13231714 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7959BC77B78 for ; Thu, 4 May 2023 19:54:20 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.530079.825433 (Exim 4.92) (envelope-from ) id 1puf1m-0007We-B9; Thu, 04 May 2023 19:54:10 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 530079.825433; Thu, 04 May 2023 19:54:10 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1puf1m-0007V5-1A; Thu, 04 May 2023 19:54:10 +0000 Received: by outflank-mailman (input) for mailman id 530079; Thu, 04 May 2023 19:54:08 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1puf1k-0003xx-DI for xen-devel@lists.xenproject.org; Thu, 04 May 2023 19:54:08 +0000 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 6c75c70b-eab5-11ed-8611-37d641c3527e; Thu, 04 May 2023 21:54:05 +0200 (CEST) Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-83-mf16-bP3ON6rSVB1WZdIzA-1; Thu, 04 May 2023 15:54:00 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E5EB4101A531; Thu, 4 May 2023 19:53:58 +0000 (UTC) Received: from localhost (unknown [10.39.192.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 00AB54020962; Thu, 4 May 2023 19:53:57 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 6c75c70b-eab5-11ed-8611-37d641c3527e DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1683230044; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TaJhEzn2xnk+TJZ+4gZYO3ndhDET6IVJHLdTW4Bnkp0=; b=OkR7Xgyrk9DRZ+GmfacqrWgXZ781Uwvtp77CWlpRDdaciJmLhCObMpDc78EIFyvv4qQ1ri 3co3ZB8Ber+KuqHQ91JXqRvsszqqCjSqyy5DNy+AQWoc286ncoAKHFaduZxCZOgSSONzv2 nGIRnXaUVCCnmXlw8aCYF7LfwZMNhmc= X-MC-Unique: mf16-bP3ON6rSVB1WZdIzA-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Ronnie Sahlberg , Aarushi Mehta , qemu-block@nongnu.org, Paul Durrant , Anthony Perard , Peter Lieven , Stefan Weil , Xie Yongji , Kevin Wolf , Paolo Bonzini , "Michael S. Tsirkin" , Leonardo Bras , Peter Xu , Hanna Reitz , Stefano Stabellini , Richard Henderson , David Woodhouse , Coiby Xu , Eduardo Habkost , Stefano Garzarella , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , Stefan Hajnoczi , Julia Suvorova , xen-devel@lists.xenproject.org, eesposit@redhat.com, Juan Quintela , "Richard W.M. Jones" , Fam Zheng , Marcel Apfelbaum Subject: [PATCH v5 11/21] block: drain from main loop thread in bdrv_co_yield_to_drain() Date: Thu, 4 May 2023 15:53:17 -0400 Message-Id: <20230504195327.695107-12-stefanha@redhat.com> In-Reply-To: <20230504195327.695107-1-stefanha@redhat.com> References: <20230504195327.695107-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 For simplicity, always run BlockDevOps .drained_begin/end/poll() callbacks in the main loop thread. This makes it easier to implement the callbacks and avoids extra locks. Move the function pointer declarations from the I/O Code section to the Global State section for BlockDevOps, BdrvChildClass, and BlockDriver. Narrow IO_OR_GS_CODE() to GLOBAL_STATE_CODE() where appropriate. The test-bdrv-drain test case calls bdrv_drain() from an IOThread. This is now only allowed from coroutine context, so update the test case to run in a coroutine. Signed-off-by: Stefan Hajnoczi --- include/block/block_int-common.h | 90 +++++++++++++-------------- include/sysemu/block-backend-common.h | 25 ++++---- block/io.c | 14 +++-- tests/unit/test-bdrv-drain.c | 14 +++-- 4 files changed, 76 insertions(+), 67 deletions(-) diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h index 013d419444..f462a8be55 100644 --- a/include/block/block_int-common.h +++ b/include/block/block_int-common.h @@ -356,6 +356,21 @@ struct BlockDriver { void (*bdrv_attach_aio_context)(BlockDriverState *bs, AioContext *new_context); + /** + * bdrv_drain_begin is called if implemented in the beginning of a + * drain operation to drain and stop any internal sources of requests in + * the driver. + * bdrv_drain_end is called if implemented at the end of the drain. + * + * They should be used by the driver to e.g. manage scheduled I/O + * requests, or toggle an internal state. After the end of the drain new + * requests will continue normally. + * + * Implementations of both functions must not call aio_poll(). + */ + void (*bdrv_drain_begin)(BlockDriverState *bs); + void (*bdrv_drain_end)(BlockDriverState *bs); + /** * Try to get @bs's logical and physical block size. * On success, store them in @bsz and return zero. @@ -743,21 +758,6 @@ struct BlockDriver { void coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_io_unplug)( BlockDriverState *bs); - /** - * bdrv_drain_begin is called if implemented in the beginning of a - * drain operation to drain and stop any internal sources of requests in - * the driver. - * bdrv_drain_end is called if implemented at the end of the drain. - * - * They should be used by the driver to e.g. manage scheduled I/O - * requests, or toggle an internal state. After the end of the drain new - * requests will continue normally. - * - * Implementations of both functions must not call aio_poll(). - */ - void (*bdrv_drain_begin)(BlockDriverState *bs); - void (*bdrv_drain_end)(BlockDriverState *bs); - bool (*bdrv_supports_persistent_dirty_bitmap)(BlockDriverState *bs); bool coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_can_store_new_dirty_bitmap)( @@ -920,36 +920,6 @@ struct BdrvChildClass { void GRAPH_WRLOCK_PTR (*attach)(BdrvChild *child); void GRAPH_WRLOCK_PTR (*detach)(BdrvChild *child); - /* - * Notifies the parent that the filename of its child has changed (e.g. - * because the direct child was removed from the backing chain), so that it - * can update its reference. - */ - int (*update_filename)(BdrvChild *child, BlockDriverState *new_base, - const char *filename, Error **errp); - - bool (*change_aio_ctx)(BdrvChild *child, AioContext *ctx, - GHashTable *visited, Transaction *tran, - Error **errp); - - /* - * I/O API functions. These functions are thread-safe. - * - * See include/block/block-io.h for more information about - * the I/O API. - */ - - void (*resize)(BdrvChild *child); - - /* - * Returns a name that is supposedly more useful for human users than the - * node name for identifying the node in question (in particular, a BB - * name), or NULL if the parent can't provide a better name. - */ - const char *(*get_name)(BdrvChild *child); - - AioContext *(*get_parent_aio_context)(BdrvChild *child); - /* * If this pair of functions is implemented, the parent doesn't issue new * requests after returning from .drained_begin() until .drained_end() is @@ -970,6 +940,36 @@ struct BdrvChildClass { * activity on the child has stopped. */ bool (*drained_poll)(BdrvChild *child); + + /* + * Notifies the parent that the filename of its child has changed (e.g. + * because the direct child was removed from the backing chain), so that it + * can update its reference. + */ + int (*update_filename)(BdrvChild *child, BlockDriverState *new_base, + const char *filename, Error **errp); + + bool (*change_aio_ctx)(BdrvChild *child, AioContext *ctx, + GHashTable *visited, Transaction *tran, + Error **errp); + + /* + * I/O API functions. These functions are thread-safe. + * + * See include/block/block-io.h for more information about + * the I/O API. + */ + + void (*resize)(BdrvChild *child); + + /* + * Returns a name that is supposedly more useful for human users than the + * node name for identifying the node in question (in particular, a BB + * name), or NULL if the parent can't provide a better name. + */ + const char *(*get_name)(BdrvChild *child); + + AioContext *(*get_parent_aio_context)(BdrvChild *child); }; extern const BdrvChildClass child_of_bds; diff --git a/include/sysemu/block-backend-common.h b/include/sysemu/block-backend-common.h index 2391679c56..780cea7305 100644 --- a/include/sysemu/block-backend-common.h +++ b/include/sysemu/block-backend-common.h @@ -59,6 +59,19 @@ typedef struct BlockDevOps { */ bool (*is_medium_locked)(void *opaque); + /* + * Runs when the backend receives a drain request. + */ + void (*drained_begin)(void *opaque); + /* + * Runs when the backend's last drain request ends. + */ + void (*drained_end)(void *opaque); + /* + * Is the device still busy? + */ + bool (*drained_poll)(void *opaque); + /* * I/O API functions. These functions are thread-safe. * @@ -76,18 +89,6 @@ typedef struct BlockDevOps { * Runs when the size changed (e.g. monitor command block_resize) */ void (*resize_cb)(void *opaque); - /* - * Runs when the backend receives a drain request. - */ - void (*drained_begin)(void *opaque); - /* - * Runs when the backend's last drain request ends. - */ - void (*drained_end)(void *opaque); - /* - * Is the device still busy? - */ - bool (*drained_poll)(void *opaque); } BlockDevOps; /* diff --git a/block/io.c b/block/io.c index 6fa1993374..532c8c90c9 100644 --- a/block/io.c +++ b/block/io.c @@ -60,7 +60,7 @@ static void bdrv_parent_drained_begin(BlockDriverState *bs, BdrvChild *ignore) void bdrv_parent_drained_end_single(BdrvChild *c) { - IO_OR_GS_CODE(); + GLOBAL_STATE_CODE(); assert(c->quiesced_parent); c->quiesced_parent = false; @@ -108,7 +108,7 @@ static bool bdrv_parent_drained_poll(BlockDriverState *bs, BdrvChild *ignore, void bdrv_parent_drained_begin_single(BdrvChild *c) { - IO_OR_GS_CODE(); + GLOBAL_STATE_CODE(); assert(!c->quiesced_parent); c->quiesced_parent = true; @@ -248,7 +248,7 @@ typedef struct { bool bdrv_drain_poll(BlockDriverState *bs, BdrvChild *ignore_parent, bool ignore_bds_parents) { - IO_OR_GS_CODE(); + GLOBAL_STATE_CODE(); if (bdrv_parent_drained_poll(bs, ignore_parent, ignore_bds_parents)) { return true; @@ -335,7 +335,8 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, if (ctx != co_ctx) { aio_context_release(ctx); } - replay_bh_schedule_oneshot_event(ctx, bdrv_co_drain_bh_cb, &data); + replay_bh_schedule_oneshot_event(qemu_get_aio_context(), + bdrv_co_drain_bh_cb, &data); qemu_coroutine_yield(); /* If we are resumed from some other event (such as an aio completion or a @@ -358,6 +359,8 @@ static void bdrv_do_drained_begin(BlockDriverState *bs, BdrvChild *parent, return; } + GLOBAL_STATE_CODE(); + /* Stop things in parent-to-child order */ if (qatomic_fetch_inc(&bs->quiesce_counter) == 0) { aio_disable_external(bdrv_get_aio_context(bs)); @@ -400,11 +403,14 @@ static void bdrv_do_drained_end(BlockDriverState *bs, BdrvChild *parent) { int old_quiesce_counter; + IO_OR_GS_CODE(); + if (qemu_in_coroutine()) { bdrv_co_yield_to_drain(bs, false, parent, false); return; } assert(bs->quiesce_counter > 0); + GLOBAL_STATE_CODE(); /* Re-enable things in child-to-parent order */ old_quiesce_counter = qatomic_fetch_dec(&bs->quiesce_counter); diff --git a/tests/unit/test-bdrv-drain.c b/tests/unit/test-bdrv-drain.c index d9d3807062..dc3cb9e0e3 100644 --- a/tests/unit/test-bdrv-drain.c +++ b/tests/unit/test-bdrv-drain.c @@ -445,19 +445,19 @@ struct test_iothread_data { BlockDriverState *bs; enum drain_type drain_type; int *aio_ret; + bool co_done; }; -static void test_iothread_drain_entry(void *opaque) +static void coroutine_fn test_iothread_drain_co_entry(void *opaque) { struct test_iothread_data *data = opaque; - aio_context_acquire(bdrv_get_aio_context(data->bs)); do_drain_begin(data->drain_type, data->bs); g_assert_cmpint(*data->aio_ret, ==, 0); do_drain_end(data->drain_type, data->bs); - aio_context_release(bdrv_get_aio_context(data->bs)); - qemu_event_set(&done_event); + data->co_done = true; + aio_wait_kick(); } static void test_iothread_aio_cb(void *opaque, int ret) @@ -493,6 +493,7 @@ static void test_iothread_common(enum drain_type drain_type, int drain_thread) BlockDriverState *bs; BDRVTestState *s; BlockAIOCB *acb; + Coroutine *co; int aio_ret; struct test_iothread_data data; @@ -571,8 +572,9 @@ static void test_iothread_common(enum drain_type drain_type, int drain_thread) } break; case 1: - aio_bh_schedule_oneshot(ctx_a, test_iothread_drain_entry, &data); - qemu_event_wait(&done_event); + co = qemu_coroutine_create(test_iothread_drain_co_entry, &data); + aio_co_enter(ctx_a, co); + AIO_WAIT_WHILE_UNLOCKED(NULL, !data.co_done); break; default: g_assert_not_reached();