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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 9F94CC48BE6 for ; Mon, 14 Jun 2021 07:38:57 +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 3B996606A5 for ; Mon, 14 Jun 2021 07:38:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B996606A5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47104 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lshBQ-000629-Cu for qemu-devel@archiver.kernel.org; Mon, 14 Jun 2021 03:38:56 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35228) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lsh6w-0005jP-HZ for qemu-devel@nongnu.org; Mon, 14 Jun 2021 03:34:18 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:55981) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lsh6u-00056O-Hb for qemu-devel@nongnu.org; Mon, 14 Jun 2021 03:34:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623656056; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RmubNJaaWOZmDxPXbzCNnNArMjoF1vbOQWWhxx6eZEI=; b=bU1mLFXlpH/LxGtCEASUp96gpq9CN1Huf6qD7RBZyy4aixNV4TZry3RlkN/tByR4BO2JPc j9HD8qXVTA0J0HzDYogUzBPsYSizSOZ5lwupUAu0rIP0d7aJ4qvPkCUmBPBHWukT4/0Xe3 0/CHOmPnP41Zv7XmYxRLJNkbkJsUaV8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-381-uIphKUlvMK6ffkpgQBzDFw-1; Mon, 14 Jun 2021 03:34:12 -0400 X-MC-Unique: uIphKUlvMK6ffkpgQBzDFw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 86B07801ADF; Mon, 14 Jun 2021 07:34:11 +0000 (UTC) Received: from localhost.localdomain (ovpn-113-49.ams2.redhat.com [10.36.113.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id 013E85D6A8; Mon, 14 Jun 2021 07:34:08 +0000 (UTC) From: Emanuele Giuseppe Esposito To: qemu-block@nongnu.org Subject: [PATCH v4 5/6] block-copy: add a CoMutex Date: Mon, 14 Jun 2021 09:33:49 +0200 Message-Id: <20210614073350.17048-6-eesposit@redhat.com> In-Reply-To: <20210614073350.17048-1-eesposit@redhat.com> References: <20210614073350.17048-1-eesposit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eesposit@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=216.205.24.124; envelope-from=eesposit@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.199, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: Kevin Wolf , Emanuele Giuseppe Esposito , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, Max Reitz , Stefan Hajnoczi , Paolo Bonzini , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Add a CoMutex to protect concurrent access of block-copy data structures. This mutex also protects .copy_bitmap, because its thread-safe API does not prevent it from assigning two tasks to the same bitmap region. .finished, .cancelled and reads to .ret and .error_is_read will be protected in the following patch, because are used also outside coroutines. Also set block_copy_task_create as coroutine_fn because: 1) it is static and only invoked by coroutine functions 2) this patch introduces and uses a CoMutex lock there Signed-off-by: Emanuele Giuseppe Esposito --- block/block-copy.c | 79 +++++++++++++++++++++++++++++--------- include/block/block-copy.h | 2 + 2 files changed, 62 insertions(+), 19 deletions(-) diff --git a/block/block-copy.c b/block/block-copy.c index afa2f484f0..6416929abd 100644 --- a/block/block-copy.c +++ b/block/block-copy.c @@ -61,6 +61,7 @@ typedef struct BlockCopyCallState { /* OUT parameters */ bool cancelled; + /* Fields protected by lock in BlockCopyState */ bool error_is_read; int ret; } BlockCopyCallState; @@ -77,8 +78,12 @@ typedef struct BlockCopyTask { int64_t offset; BlockCopyMethod method; - /* State */ + /* State. Protected by lock in BlockCopyState */ CoQueue wait_queue; /* coroutines blocked on this task */ + /* + * Only protect the case of parallel read while updating @bytes + * value in block_copy_task_shrink(). + */ int64_t bytes; QLIST_ENTRY(BlockCopyTask) list; } BlockCopyTask; @@ -97,7 +102,8 @@ typedef struct BlockCopyState { BdrvChild *source; BdrvChild *target; - /* State */ + /* State. Protected by lock */ + CoMutex lock; int64_t in_flight_bytes; BlockCopyMethod method; QLIST_HEAD(, BlockCopyTask) tasks; /* All tasks from all block-copy calls */ @@ -137,6 +143,7 @@ typedef struct BlockCopyState { bool skip_unallocated; } BlockCopyState; +/* Called with lock held */ static BlockCopyTask *find_conflicting_task(BlockCopyState *s, int64_t offset, int64_t bytes) { @@ -154,6 +161,8 @@ static BlockCopyTask *find_conflicting_task(BlockCopyState *s, /* * If there are no intersecting tasks return false. Otherwise, wait for the * first found intersecting tasks to finish and return true. + * + * Called with lock held. */ static bool coroutine_fn block_copy_wait_one(BlockCopyState *s, int64_t offset, int64_t bytes) @@ -164,7 +173,7 @@ static bool coroutine_fn block_copy_wait_one(BlockCopyState *s, int64_t offset, return false; } - qemu_co_queue_wait(&task->wait_queue, NULL); + qemu_co_queue_wait(&task->wait_queue, &s->lock); return true; } @@ -191,14 +200,15 @@ static int64_t block_copy_chunk_size(BlockCopyState *s) * Search for the first dirty area in offset/bytes range and create task at * the beginning of it. */ -static BlockCopyTask *block_copy_task_create(BlockCopyState *s, - BlockCopyCallState *call_state, - int64_t offset, int64_t bytes) +static coroutine_fn BlockCopyTask *block_copy_task_create(BlockCopyState *s, + BlockCopyCallState *call_state, + int64_t offset, int64_t bytes) { BlockCopyTask *task; - int64_t max_chunk = block_copy_chunk_size(s); + int64_t max_chunk; - max_chunk = MIN_NON_ZERO(max_chunk, call_state->max_chunk); + QEMU_LOCK_GUARD(&s->lock); + max_chunk = MIN_NON_ZERO(block_copy_chunk_size(s), call_state->max_chunk); if (!bdrv_dirty_bitmap_next_dirty_area(s->copy_bitmap, offset, offset + bytes, max_chunk, &offset, &bytes)) @@ -240,6 +250,7 @@ static BlockCopyTask *block_copy_task_create(BlockCopyState *s, static void coroutine_fn block_copy_task_shrink(BlockCopyTask *task, int64_t new_bytes) { + QEMU_LOCK_GUARD(&task->s->lock); if (new_bytes == task->bytes) { return; } @@ -256,6 +267,7 @@ static void coroutine_fn block_copy_task_shrink(BlockCopyTask *task, static void coroutine_fn block_copy_task_end(BlockCopyTask *task, int ret) { + QEMU_LOCK_GUARD(&task->s->lock); task->s->in_flight_bytes -= task->bytes; if (ret < 0) { bdrv_set_dirty_bitmap(task->s->copy_bitmap, task->offset, task->bytes); @@ -334,12 +346,14 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target, } ratelimit_init(&s->rate_limit); + qemu_co_mutex_init(&s->lock); QLIST_INIT(&s->tasks); QLIST_INIT(&s->calls); return s; } +/* Only set before running the job, so it is thread safe to call. */ void block_copy_set_progress_meter(BlockCopyState *s, ProgressMeter *pm) { s->progress = pm; @@ -480,16 +494,20 @@ static coroutine_fn int block_copy_task_entry(AioTask *task) int ret; ret = block_copy_do_copy(s, t->offset, t->bytes, &method, &error_is_read); - if (s->method == t->method) { - s->method = method; - } - if (ret < 0) { - if (!t->call_state->ret) { - t->call_state->ret = ret; - t->call_state->error_is_read = error_is_read; + + WITH_QEMU_LOCK_GUARD(&s->lock) { + if (s->method == t->method) { + s->method = method; + } + + if (ret < 0) { + if (!t->call_state->ret) { + t->call_state->ret = ret; + t->call_state->error_is_read = error_is_read; + } + } else { + progress_work_done(s->progress, t->bytes); } - } else { - progress_work_done(s->progress, t->bytes); } co_put_to_shres(s->mem, t->bytes); block_copy_task_end(t, ret); @@ -591,10 +609,12 @@ int64_t block_copy_reset_unallocated(BlockCopyState *s, bytes = clusters * s->cluster_size; if (!ret) { + qemu_co_mutex_lock(&s->lock); bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes); progress_set_remaining(s->progress, bdrv_get_dirty_count(s->copy_bitmap) + s->in_flight_bytes); + qemu_co_mutex_unlock(&s->lock); } *count = bytes; @@ -734,14 +754,33 @@ static int coroutine_fn block_copy_common(BlockCopyCallState *call_state) int ret; BlockCopyState *s = call_state->s; + qemu_co_mutex_lock(&s->lock); QLIST_INSERT_HEAD(&s->calls, call_state, list); + qemu_co_mutex_unlock(&s->lock); do { ret = block_copy_dirty_clusters(call_state); if (ret == 0 && !call_state->cancelled) { - ret = block_copy_wait_one(s, call_state->offset, - call_state->bytes); + WITH_QEMU_LOCK_GUARD(&s->lock) { + /* + * Check that there is no task we still need to + * wait to complete + */ + ret = block_copy_wait_one(s, call_state->offset, + call_state->bytes); + if (ret == 0) { + /* + * No pending tasks, but check again the bitmap in this + * same critical section, since a task might have failed + * between this and the critical section in + * block_copy_dirty_clusters(). + */ + ret = bdrv_dirty_bitmap_next_dirty(s->copy_bitmap, + call_state->offset, + call_state->bytes) > 0; + } + } } /* @@ -761,7 +800,9 @@ static int coroutine_fn block_copy_common(BlockCopyCallState *call_state) call_state->cb(call_state->cb_opaque); } + qemu_co_mutex_lock(&s->lock); QLIST_REMOVE(call_state, list); + qemu_co_mutex_unlock(&s->lock); return ret; } diff --git a/include/block/block-copy.h b/include/block/block-copy.h index 338f2ea7fd..bf8f0c679f 100644 --- a/include/block/block-copy.h +++ b/include/block/block-copy.h @@ -18,6 +18,8 @@ #include "block/block.h" #include "qemu/co-shared-resource.h" +/* All APIs are thread-safe*/ + typedef void (*BlockCopyAsyncCallbackFunc)(void *opaque); typedef struct BlockCopyState BlockCopyState; typedef struct BlockCopyCallState BlockCopyCallState; -- 2.31.1