From patchwork Thu Dec 21 19:24:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13502592 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.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 smtp.lore.kernel.org (Postfix) with ESMTPS id DA084C46CD4 for ; Thu, 21 Dec 2023 19:25:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rGOfM-0001O3-3A; Thu, 21 Dec 2023 14:25:08 -0500 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 1rGOfH-0001N0-JQ for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:04 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rGOfG-0001pz-0M for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1703186700; 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=Z6GWwX5cBUe5INCQZNIbh12/Fu0Hcv2jrD8zOggAzlc=; b=B5o9xIaXZUEKKZ7wOMPGmAffJPRdReRqdJsMyJb8OV1i4b7jtg3Y1WqpTVf1OotNGcbwHL 1WqLlGPr1HAn/Kb7debFOvxMTllEqtzjisRr04fbPrvdfl7x4XB0vBXEqAYttByXUsKObQ nTEST3njcQTgD7APBVUU7SrbuQmjUAY= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-68-eIdGkD9qPtaoMaxjkC1XBA-1; Thu, 21 Dec 2023 14:24:56 -0500 X-MC-Unique: eIdGkD9qPtaoMaxjkC1XBA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 778F91C04B51; Thu, 21 Dec 2023 19:24:56 +0000 (UTC) Received: from localhost (unknown [10.39.194.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id D2594492BC6; Thu, 21 Dec 2023 19:24:55 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org, Kevin Wolf Cc: Juan Quintela , Vladimir Sementsov-Ogievskiy , pbonzini@redhat.com, Peter Xu , qemu-block@nongnu.org, Hanna Reitz , Fabiano Rosas , Leonardo Bras , Eric Blake , Stefan Hajnoczi , Fam Zheng Subject: [PATCH v3 1/6] fixup block-coroutine-wrapper: use qemu_get_current_aio_context() Date: Thu, 21 Dec 2023 14:24:47 -0500 Message-ID: <20231221192452.1785567-2-stefanha@redhat.com> In-Reply-To: <20231221192452.1785567-1-stefanha@redhat.com> References: <20231221192452.1785567-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.061, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org qemu-iotests 051 fails on my machine so the change to 051.pc.out made by the above commit appears to be incorrect, at least against the current QEMU source tree. Revert it so that 051 passes again. Signed-off-by: Stefan Hajnoczi --- tests/qemu-iotests/051.pc.out | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tests/qemu-iotests/051.pc.out b/tests/qemu-iotests/051.pc.out index 86a3e113c4..7e10c5fa1b 100644 --- a/tests/qemu-iotests/051.pc.out +++ b/tests/qemu-iotests/051.pc.out @@ -177,11 +177,11 @@ QEMU X.Y.Z monitor - type 'help' for more information Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device lsi53c895a,id=lsi0 -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on QEMU X.Y.Z monitor - type 'help' for more information -QEMU_PROG: -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on: HBA does not support iothreads +(qemu) QEMU_PROG: -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on: HBA does not support iothreads Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-scsi,id=virtio-scsi1 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on QEMU X.Y.Z monitor - type 'help' for more information -QEMU_PROG: -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on: Cannot change iothread of active block backend +(qemu) QEMU_PROG: -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on: Cannot change iothread of active block backend Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-blk-pci,drive=disk,iothread=thread0,share-rw=on QEMU X.Y.Z monitor - type 'help' for more information From patchwork Thu Dec 21 19:24:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13502591 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.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 smtp.lore.kernel.org (Postfix) with ESMTPS id 8FAE4C35274 for ; Thu, 21 Dec 2023 19:25:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rGOfc-0001TY-6n; Thu, 21 Dec 2023 14:25:25 -0500 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 1rGOfY-0001Si-Lm for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rGOfJ-0001qf-3M for qemu-devel@nongnu.org; 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Thu, 21 Dec 2023 19:24:58 +0000 (UTC) Received: from localhost (unknown [10.39.194.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1C2621121313; Thu, 21 Dec 2023 19:24:57 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org, Kevin Wolf Cc: Juan Quintela , Vladimir Sementsov-Ogievskiy , pbonzini@redhat.com, Peter Xu , qemu-block@nongnu.org, Hanna Reitz , Fabiano Rosas , Leonardo Bras , Eric Blake , Stefan Hajnoczi , Fam Zheng Subject: [PATCH v3 2/6] fixup block: remove AioContext locking Date: Thu, 21 Dec 2023 14:24:48 -0500 Message-ID: <20231221192452.1785567-3-stefanha@redhat.com> In-Reply-To: <20231221192452.1785567-1-stefanha@redhat.com> References: <20231221192452.1785567-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.061, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01, T_SPF_HELO_TEMPERROR=0.01 autolearn=unavailable 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Signed-off-by: Stefan Hajnoczi --- migration/block.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/migration/block.c b/migration/block.c index 2bcfcbfdf6..6ec6a1d6e6 100644 --- a/migration/block.c +++ b/migration/block.c @@ -311,10 +311,17 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds) block_mig_state.submitted++; blk_mig_unlock(); + /* + * The migration thread does not have an AioContext. Lock the BQL so that + * I/O runs in the main loop AioContext (see + * qemu_get_current_aio_context()). + */ + qemu_mutex_lock_iothread(); bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector * BDRV_SECTOR_SIZE, nr_sectors * BDRV_SECTOR_SIZE); blk->aiocb = blk_aio_preadv(bb, cur_sector * BDRV_SECTOR_SIZE, &blk->qiov, 0, blk_mig_read_cb, blk); + qemu_mutex_unlock_iothread(); bmds->cur_sector = cur_sector + nr_sectors; return (bmds->cur_sector >= total_sectors); From patchwork Thu Dec 21 19:24:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13502593 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.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 smtp.lore.kernel.org (Postfix) with ESMTPS id E7C15C46CD8 for ; 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envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.061, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01, T_SPF_HELO_TEMPERROR=0.01 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Signed-off-by: Stefan Hajnoczi Reviewed-by: Paolo Bonzini --- hw/scsi/scsi-bus.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c index df68a44b6a..5b08cbf60a 100644 --- a/hw/scsi/scsi-bus.c +++ b/hw/scsi/scsi-bus.c @@ -127,7 +127,8 @@ static void scsi_device_for_each_req_async_bh(void *opaque) */ ctx = blk_get_aio_context(s->conf.blk); if (ctx != qemu_get_current_aio_context()) { - aio_bh_schedule_oneshot(ctx, scsi_device_for_each_req_async_bh, data); + aio_bh_schedule_oneshot(ctx, scsi_device_for_each_req_async_bh, + g_steal_pointer(&data)); return; } From patchwork Thu Dec 21 19:24:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13502595 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.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 smtp.lore.kernel.org (Postfix) with ESMTPS id 49606C46CD4 for ; Thu, 21 Dec 2023 19:26:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rGOfV-0001Qj-Md; Thu, 21 Dec 2023 14:25:17 -0500 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 1rGOfT-0001Pn-Ve for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:15 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rGOfL-000230-T5 for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:15 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1703186706; 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=yqk4OFQOKT4s9q1FhkTw1+IEsq2kegWN4COgjx1UDyc=; b=BklmLzDrQXuc3IgX1CXQIVLrdxW7I2vAOtIw/0il5EFNHVBsIFmljXrTZr4VOobaXVp48V 7cie5OrvEGA3IRiKASb/JeehjrLHUnwG8eKYPZdMdwssQueSIIdKTi51Zy3EVKzMnbci2y hbSUqDaFnGTmjPYfwwNx+2WyAueMxWM= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-62-Ua_GNtDNP9uxN9d5btR23Q-1; Thu, 21 Dec 2023 14:25:03 -0500 X-MC-Unique: Ua_GNtDNP9uxN9d5btR23Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9D0531C04B6C; Thu, 21 Dec 2023 19:25:02 +0000 (UTC) Received: from localhost (unknown [10.39.194.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1809E51D5; Thu, 21 Dec 2023 19:25:01 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org, Kevin Wolf Cc: Juan Quintela , Vladimir Sementsov-Ogievskiy , pbonzini@redhat.com, Peter Xu , qemu-block@nongnu.org, Hanna Reitz , Fabiano Rosas , Leonardo Bras , Eric Blake , Stefan Hajnoczi , Fam Zheng Subject: [PATCH v3 4/6] nbd/server: avoid per-NBDRequest nbd_client_get/put() Date: Thu, 21 Dec 2023 14:24:50 -0500 Message-ID: <20231221192452.1785567-5-stefanha@redhat.com> In-Reply-To: <20231221192452.1785567-1-stefanha@redhat.com> References: <20231221192452.1785567-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.061, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org nbd_trip() processes a single NBD request from start to finish and holds an NBDClient reference throughout. NBDRequest does not outlive the scope of nbd_trip(). Therefore it is unnecessary to ref/unref NBDClient for each NBDRequest. Removing these nbd_client_get()/nbd_client_put() calls will make thread-safety easier in the commits that follow. Signed-off-by: Stefan Hajnoczi Reviewed-by: Paolo Bonzini --- nbd/server.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index 895cf0a752..0b09ccc8dc 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1557,7 +1557,6 @@ static NBDRequestData *nbd_request_get(NBDClient *client) client->nb_requests++; req = g_new0(NBDRequestData, 1); - nbd_client_get(client); req->client = client; return req; } @@ -1578,8 +1577,6 @@ static void nbd_request_put(NBDRequestData *req) } nbd_client_receive_next_request(client); - - nbd_client_put(client); } static void blk_aio_attached(AioContext *ctx, void *opaque) From patchwork Thu Dec 21 19:24:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13502590 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.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 smtp.lore.kernel.org (Postfix) with ESMTPS id D8F16C35274 for ; Thu, 21 Dec 2023 19:25:54 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rGOfY-0001SZ-3a; Thu, 21 Dec 2023 14:25:20 -0500 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 1rGOfW-0001Rg-UG for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:18 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rGOfN-00023J-Ug for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1703186708; 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=mK+NLIDFhmr0TUKTwrjSQoiP7pMtYM6wCDVaFG6Vy34=; b=PlKafKjbrTQzTANHSIIRqRLn7Teb1G3O4QBRdV2X+ky+pVSjpv2hhRNU2VG1kR95TjVJ61 ATOFT5bdyPU5PrPE2C3FOS7Ua+G7jKZTF5q9vOx6QpmgeOjdfrjgDawAcrAN3+zN9klHKf p61J9hF5kwWh7Y0XrS/qt1ZPYJtT9Vw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-269--gsX0rAlMt2lUQRcrpGk5Q-1; Thu, 21 Dec 2023 14:25:05 -0500 X-MC-Unique: -gsX0rAlMt2lUQRcrpGk5Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 317B08370EC; Thu, 21 Dec 2023 19:25:05 +0000 (UTC) Received: from localhost (unknown [10.39.194.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id A32D52026F95; Thu, 21 Dec 2023 19:25:04 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org, Kevin Wolf Cc: Juan Quintela , Vladimir Sementsov-Ogievskiy , pbonzini@redhat.com, Peter Xu , qemu-block@nongnu.org, Hanna Reitz , Fabiano Rosas , Leonardo Bras , Eric Blake , Stefan Hajnoczi , Fam Zheng Subject: [PATCH v3 5/6] nbd/server: only traverse NBDExport->clients from main loop thread Date: Thu, 21 Dec 2023 14:24:51 -0500 Message-ID: <20231221192452.1785567-6-stefanha@redhat.com> In-Reply-To: <20231221192452.1785567-1-stefanha@redhat.com> References: <20231221192452.1785567-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.061, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org The NBD clients list is currently accessed from both the export AioContext and the main loop thread. When the AioContext lock is removed there will be nothing protecting the clients list. Adding a lock around the clients list is tricky because NBDClient structs are refcounted and may be freed from the export AioContext or the main loop thread. nbd_export_request_shutdown() -> client_close() -> nbd_client_put() is also tricky because the list lock would be held while indirectly dropping references to NDBClients. A simpler approach is to only allow nbd_client_put() and client_close() calls from the main loop thread. Then the NBD clients list is only accessed from the main loop thread and no fancy locking is needed. nbd_trip() just needs to reschedule itself in the main loop AioContext before calling nbd_client_put() and client_close(). This costs more CPU cycles per NBD request so add nbd_client_put_nonzero() to optimize the common case where more references to NBDClient remain. Note that nbd_client_get() can still be called from either thread, so make NBDClient->refcount atomic. Signed-off-by: Stefan Hajnoczi --- nbd/server.c | 61 +++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 51 insertions(+), 10 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index 0b09ccc8dc..e91e2e0903 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -122,7 +122,7 @@ struct NBDMetaContexts { }; struct NBDClient { - int refcount; + int refcount; /* atomic */ void (*close_fn)(NBDClient *client, bool negotiated); NBDExport *exp; @@ -1501,14 +1501,17 @@ static int coroutine_fn nbd_receive_request(NBDClient *client, NBDRequest *reque #define MAX_NBD_REQUESTS 16 +/* Runs in export AioContext and main loop thread */ void nbd_client_get(NBDClient *client) { - client->refcount++; + qatomic_inc(&client->refcount); } void nbd_client_put(NBDClient *client) { - if (--client->refcount == 0) { + assert(qemu_in_main_thread()); + + if (qatomic_fetch_dec(&client->refcount) == 1) { /* The last reference should be dropped by client->close, * which is called by client_close. */ @@ -1529,8 +1532,35 @@ void nbd_client_put(NBDClient *client) } } +/* + * Tries to release the reference to @client, but only if other references + * remain. This is an optimization for the common case where we want to avoid + * the expense of scheduling nbd_client_put() in the main loop thread. + * + * Returns true upon success or false if the reference was not released because + * it is the last reference. + */ +static bool nbd_client_put_nonzero(NBDClient *client) +{ + int old = qatomic_read(&client->refcount); + int expected; + + do { + if (old == 1) { + return false; + } + + expected = old; + old = qatomic_cmpxchg(&client->refcount, expected, expected - 1); + } while (old != expected); + + return true; +} + static void client_close(NBDClient *client, bool negotiated) { + assert(qemu_in_main_thread()); + if (client->closing) { return; } @@ -2933,15 +2963,20 @@ static coroutine_fn int nbd_handle_request(NBDClient *client, static coroutine_fn void nbd_trip(void *opaque) { NBDClient *client = opaque; - NBDRequestData *req; + NBDRequestData *req = NULL; NBDRequest request = { 0 }; /* GCC thinks it can be used uninitialized */ int ret; Error *local_err = NULL; + /* + * Note that nbd_client_put() and client_close() must be called from the + * main loop thread. Use aio_co_reschedule_self() to switch AioContext + * before calling these functions. + */ + trace_nbd_trip(); if (client->closing) { - nbd_client_put(client); - return; + goto done; } if (client->quiescing) { @@ -2949,10 +2984,9 @@ static coroutine_fn void nbd_trip(void *opaque) * We're switching between AIO contexts. Don't attempt to receive a new * request and kick the main context which may be waiting for us. */ - nbd_client_put(client); client->recv_coroutine = NULL; aio_wait_kick(); - return; + goto done; } req = nbd_request_get(client); @@ -3012,8 +3046,13 @@ static coroutine_fn void nbd_trip(void *opaque) qio_channel_set_cork(client->ioc, false); done: - nbd_request_put(req); - nbd_client_put(client); + if (req) { + nbd_request_put(req); + } + if (!nbd_client_put_nonzero(client)) { + aio_co_reschedule_self(qemu_get_aio_context()); + nbd_client_put(client); + } return; disconnect: @@ -3021,6 +3060,8 @@ disconnect: error_reportf_err(local_err, "Disconnect client, due to: "); } nbd_request_put(req); + + aio_co_reschedule_self(qemu_get_aio_context()); client_close(client, true); nbd_client_put(client); } From patchwork Thu Dec 21 19:24:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 13502594 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.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 smtp.lore.kernel.org (Postfix) with ESMTPS id 43F8EC35274 for ; Thu, 21 Dec 2023 19:26:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rGOfZ-0001TG-HH; Thu, 21 Dec 2023 14:25:21 -0500 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 1rGOfX-0001Rq-47 for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:19 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rGOfP-00023R-0t for qemu-devel@nongnu.org; Thu, 21 Dec 2023 14:25:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1703186709; 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=wy0gnLiaJ8egKg9TrWO6YxGfb6MtQIx7kCPRsGcYHFM=; b=fs6K5NmBsaWYtOOV9B4S5+4mQpixTqxDisJRElARmcAeKVygH125xNjiYwap4liYjJ0xIc B/c2Xxhi9A0+Kkm4jfLdHaMke0XvyeoEuYPHLnXPkPj63pE5BrPl0fHAzGwCr6ozJ5ePRQ yIcLLVTX8a5yZcNuqNw/L2aDA0U2c4s= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-647-Vs4iSQtOPXWfa5GYXvhDWg-1; Thu, 21 Dec 2023 14:25:08 -0500 X-MC-Unique: Vs4iSQtOPXWfa5GYXvhDWg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 11B40380008B; Thu, 21 Dec 2023 19:25:08 +0000 (UTC) Received: from localhost (unknown [10.39.194.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1F25251D5; Thu, 21 Dec 2023 19:25:06 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org, Kevin Wolf Cc: Juan Quintela , Vladimir Sementsov-Ogievskiy , pbonzini@redhat.com, Peter Xu , qemu-block@nongnu.org, Hanna Reitz , Fabiano Rosas , Leonardo Bras , Eric Blake , Stefan Hajnoczi , Fam Zheng Subject: [PATCH v3 6/6] nbd/server: introduce NBDClient->lock to protect fields Date: Thu, 21 Dec 2023 14:24:52 -0500 Message-ID: <20231221192452.1785567-7-stefanha@redhat.com> In-Reply-To: <20231221192452.1785567-1-stefanha@redhat.com> References: <20231221192452.1785567-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.061, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org NBDClient has a number of fields that are accessed by both the export AioContext and the main loop thread. When the AioContext lock is removed these fields will need another form of protection. Add NBDClient->lock and protect fields that are accessed by both threads. Also add assertions where possible and otherwise add doc comments stating assumptions about which thread and lock holding. Note this patch moves the client->recv_coroutine assertion from nbd_co_receive_request() to nbd_trip() where client->lock is held. Signed-off-by: Stefan Hajnoczi --- nbd/server.c | 144 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 111 insertions(+), 33 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index e91e2e0903..941832f178 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -125,23 +125,25 @@ struct NBDClient { int refcount; /* atomic */ void (*close_fn)(NBDClient *client, bool negotiated); + QemuMutex lock; + NBDExport *exp; QCryptoTLSCreds *tlscreds; char *tlsauthz; QIOChannelSocket *sioc; /* The underlying data channel */ QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */ - Coroutine *recv_coroutine; + Coroutine *recv_coroutine; /* protected by lock */ CoMutex send_lock; Coroutine *send_coroutine; - bool read_yielding; - bool quiescing; + bool read_yielding; /* protected by lock */ + bool quiescing; /* protected by lock */ QTAILQ_ENTRY(NBDClient) next; - int nb_requests; - bool closing; + int nb_requests; /* protected by lock */ + bool closing; /* protected by lock */ uint32_t check_align; /* If non-zero, check for aligned client requests */ @@ -1415,11 +1417,18 @@ nbd_read_eof(NBDClient *client, void *buffer, size_t size, Error **errp) len = qio_channel_readv(client->ioc, &iov, 1, errp); if (len == QIO_CHANNEL_ERR_BLOCK) { - client->read_yielding = true; + WITH_QEMU_LOCK_GUARD(&client->lock) { + client->read_yielding = true; + + /* Prompt main loop thread to re-run nbd_drained_poll() */ + aio_wait_kick(); + } qio_channel_yield(client->ioc, G_IO_IN); - client->read_yielding = false; - if (client->quiescing) { - return -EAGAIN; + WITH_QEMU_LOCK_GUARD(&client->lock) { + client->read_yielding = false; + if (client->quiescing) { + return -EAGAIN; + } } continue; } else if (len < 0) { @@ -1528,6 +1537,7 @@ void nbd_client_put(NBDClient *client) blk_exp_unref(&client->exp->common); } g_free(client->contexts.bitmaps); + qemu_mutex_destroy(&client->lock); g_free(client); } } @@ -1561,11 +1571,13 @@ static void client_close(NBDClient *client, bool negotiated) { assert(qemu_in_main_thread()); - if (client->closing) { - return; - } + WITH_QEMU_LOCK_GUARD(&client->lock) { + if (client->closing) { + return; + } - client->closing = true; + client->closing = true; + } /* Force requests to finish. They will drop their own references, * then we'll close the socket and free the NBDClient. @@ -1579,6 +1591,7 @@ static void client_close(NBDClient *client, bool negotiated) } } +/* Runs in export AioContext with client->lock held */ static NBDRequestData *nbd_request_get(NBDClient *client) { NBDRequestData *req; @@ -1591,6 +1604,7 @@ static NBDRequestData *nbd_request_get(NBDClient *client) return req; } +/* Runs in export AioContext with client->lock held */ static void nbd_request_put(NBDRequestData *req) { NBDClient *client = req->client; @@ -1614,14 +1628,18 @@ static void blk_aio_attached(AioContext *ctx, void *opaque) NBDExport *exp = opaque; NBDClient *client; + assert(qemu_in_main_thread()); + trace_nbd_blk_aio_attached(exp->name, ctx); exp->common.ctx = ctx; QTAILQ_FOREACH(client, &exp->clients, next) { - assert(client->nb_requests == 0); - assert(client->recv_coroutine == NULL); - assert(client->send_coroutine == NULL); + WITH_QEMU_LOCK_GUARD(&client->lock) { + assert(client->nb_requests == 0); + assert(client->recv_coroutine == NULL); + assert(client->send_coroutine == NULL); + } } } @@ -1629,6 +1647,8 @@ static void blk_aio_detach(void *opaque) { NBDExport *exp = opaque; + assert(qemu_in_main_thread()); + trace_nbd_blk_aio_detach(exp->name, exp->common.ctx); exp->common.ctx = NULL; @@ -1639,8 +1659,12 @@ static void nbd_drained_begin(void *opaque) NBDExport *exp = opaque; NBDClient *client; + assert(qemu_in_main_thread()); + QTAILQ_FOREACH(client, &exp->clients, next) { - client->quiescing = true; + WITH_QEMU_LOCK_GUARD(&client->lock) { + client->quiescing = true; + } } } @@ -1649,28 +1673,48 @@ static void nbd_drained_end(void *opaque) NBDExport *exp = opaque; NBDClient *client; + assert(qemu_in_main_thread()); + QTAILQ_FOREACH(client, &exp->clients, next) { - client->quiescing = false; - nbd_client_receive_next_request(client); + WITH_QEMU_LOCK_GUARD(&client->lock) { + client->quiescing = false; + nbd_client_receive_next_request(client); + } } } +/* Runs in export AioContext */ +static void nbd_wake_read_bh(void *opaque) +{ + NBDClient *client = opaque; + qio_channel_wake_read(client->ioc); +} + static bool nbd_drained_poll(void *opaque) { NBDExport *exp = opaque; NBDClient *client; + assert(qemu_in_main_thread()); + QTAILQ_FOREACH(client, &exp->clients, next) { - if (client->nb_requests != 0) { - /* - * If there's a coroutine waiting for a request on nbd_read_eof() - * enter it here so we don't depend on the client to wake it up. - */ - if (client->recv_coroutine != NULL && client->read_yielding) { - qio_channel_wake_read(client->ioc); + WITH_QEMU_LOCK_GUARD(&client->lock) { + if (client->nb_requests != 0) { + /* + * If there's a coroutine waiting for a request on nbd_read_eof() + * enter it here so we don't depend on the client to wake it up. + * + * Schedule a BH in the export AioContext to avoid missing the + * wake up due to the race between qio_channel_wake_read() and + * qio_channel_yield(). + */ + if (client->recv_coroutine != NULL && client->read_yielding) { + aio_bh_schedule_oneshot(nbd_export_aio_context(client->exp), + nbd_wake_read_bh, client); + } + + return true; } - - return true; } } @@ -1681,6 +1725,8 @@ static void nbd_eject_notifier(Notifier *n, void *data) { NBDExport *exp = container_of(n, NBDExport, eject_notifier); + assert(qemu_in_main_thread()); + blk_exp_request_shutdown(&exp->common); } @@ -2566,7 +2612,6 @@ static int coroutine_fn nbd_co_receive_request(NBDRequestData *req, int ret; g_assert(qemu_in_coroutine()); - assert(client->recv_coroutine == qemu_coroutine_self()); ret = nbd_receive_request(client, request, errp); if (ret < 0) { return ret; @@ -2975,6 +3020,9 @@ static coroutine_fn void nbd_trip(void *opaque) */ trace_nbd_trip(); + + qemu_mutex_lock(&client->lock); + if (client->closing) { goto done; } @@ -2990,7 +3038,21 @@ static coroutine_fn void nbd_trip(void *opaque) } req = nbd_request_get(client); - ret = nbd_co_receive_request(req, &request, &local_err); + + /* + * nbd_co_receive_request() returns -EAGAIN when nbd_drained_begin() has + * set client->quiescing but by the time we get back nbd_drained_end() may + * have already cleared client->quiescing. In that case we try again + * because nothing else will spawn an nbd_trip() coroutine until we set + * client->recv_coroutine = NULL further down. + */ + do { + assert(client->recv_coroutine == qemu_coroutine_self()); + qemu_mutex_unlock(&client->lock); + ret = nbd_co_receive_request(req, &request, &local_err); + qemu_mutex_lock(&client->lock); + } while (ret == -EAGAIN && !client->quiescing); + client->recv_coroutine = NULL; if (client->closing) { @@ -3002,15 +3064,16 @@ static coroutine_fn void nbd_trip(void *opaque) } if (ret == -EAGAIN) { - assert(client->quiescing); goto done; } nbd_client_receive_next_request(client); + if (ret == -EIO) { goto disconnect; } + qemu_mutex_unlock(&client->lock); qio_channel_set_cork(client->ioc, true); if (ret < 0) { @@ -3030,6 +3093,10 @@ static coroutine_fn void nbd_trip(void *opaque) g_free(request.contexts->bitmaps); g_free(request.contexts); } + + qio_channel_set_cork(client->ioc, false); + qemu_mutex_lock(&client->lock); + if (ret < 0) { error_prepend(&local_err, "Failed to send reply: "); goto disconnect; @@ -3044,11 +3111,13 @@ static coroutine_fn void nbd_trip(void *opaque) goto disconnect; } - qio_channel_set_cork(client->ioc, false); done: if (req) { nbd_request_put(req); } + + qemu_mutex_unlock(&client->lock); + if (!nbd_client_put_nonzero(client)) { aio_co_reschedule_self(qemu_get_aio_context()); nbd_client_put(client); @@ -3059,13 +3128,19 @@ disconnect: if (local_err) { error_reportf_err(local_err, "Disconnect client, due to: "); } + nbd_request_put(req); + qemu_mutex_unlock(&client->lock); aio_co_reschedule_self(qemu_get_aio_context()); client_close(client, true); nbd_client_put(client); } +/* + * Runs in export AioContext and main loop thread. Caller must hold + * client->lock. + */ static void nbd_client_receive_next_request(NBDClient *client) { if (!client->recv_coroutine && client->nb_requests < MAX_NBD_REQUESTS && @@ -3091,7 +3166,9 @@ static coroutine_fn void nbd_co_client_start(void *opaque) return; } - nbd_client_receive_next_request(client); + WITH_QEMU_LOCK_GUARD(&client->lock) { + nbd_client_receive_next_request(client); + } } /* @@ -3108,6 +3185,7 @@ void nbd_client_new(QIOChannelSocket *sioc, Coroutine *co; client = g_new0(NBDClient, 1); + qemu_mutex_init(&client->lock); client->refcount = 1; client->tlscreds = tlscreds; if (tlscreds) {