From patchwork Wed Oct 30 15:07:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 11219743 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8E74E13B1 for ; Wed, 30 Oct 2019 15:08:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 64356208C0 for ; Wed, 30 Oct 2019 15:08:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BqNmjNu8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726784AbfJ3PIP (ORCPT ); Wed, 30 Oct 2019 11:08:15 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:39194 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726772AbfJ3PHv (ORCPT ); Wed, 30 Oct 2019 11:07:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572448069; 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=X/BAPwzaK/VJWK6Euc/hOkg2V08gfO99tWNJkHvuumY=; b=BqNmjNu88ryFH2Mg0xNhZ2PO3P7D753sI+6IB6YAqLi0BkkbcWwduCfiz0Fbeh42BaJBHg g1CYarYiq+IcmmniJkXpsT1HIVngvUobNSIg0LGAFUnYCwTHCDVgkcD1Qf+LSb2Y12fE88 Jxl6gJDo5p64jjJ966wvwFe+I+AvhVw= 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-400-71cRbL-gN9-DhBO2t6aLVw-1; Wed, 30 Oct 2019 11:07:46 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DFE5F107ACC0; Wed, 30 Oct 2019 15:07:44 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5B6C160C85; Wed, 30 Oct 2019 15:07:39 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id E0B832256E4; Wed, 30 Oct 2019 11:07:38 -0400 (EDT) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, virtio-fs@redhat.com Cc: virtualization@lists.linux-foundation.org, vgoyal@redhat.com, miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com Subject: [PATCH 3/3] virtiofs: Use completions while waiting for queue to be drained Date: Wed, 30 Oct 2019 11:07:19 -0400 Message-Id: <20191030150719.29048-4-vgoyal@redhat.com> In-Reply-To: <20191030150719.29048-1-vgoyal@redhat.com> References: <20191030150719.29048-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: 71cRbL-gN9-DhBO2t6aLVw-1 X-Mimecast-Spam-Score: 0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org While we wait for queue to finish draining, use completions instead of uslee_range(). This is better way of waiting for event. Signed-off-by: Vivek Goyal --- fs/fuse/virtio_fs.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 43224db8d9ed..b5ba83ef1914 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -35,6 +35,7 @@ struct virtio_fs_vq { struct fuse_dev *fud; bool connected; long in_flight; + struct completion in_flight_zero; /* No inflight requests */ char name[24]; } ____cacheline_aligned_in_smp; @@ -85,6 +86,8 @@ static inline void dec_in_flight_req(struct virtio_fs_vq *fsvq) { WARN_ON(fsvq->in_flight <= 0); fsvq->in_flight--; + if (!fsvq->in_flight) + complete(&fsvq->in_flight_zero); } static void release_virtio_fs_obj(struct kref *ref) @@ -115,22 +118,23 @@ static void virtio_fs_drain_queue(struct virtio_fs_vq *fsvq) WARN_ON(fsvq->in_flight < 0); /* Wait for in flight requests to finish.*/ - while (1) { - spin_lock(&fsvq->lock); - if (!fsvq->in_flight) { - spin_unlock(&fsvq->lock); - break; - } + spin_lock(&fsvq->lock); + if (fsvq->in_flight) { + /* We are holding virtio_fs_mutex. There should not be any + * waiters waiting for completion. + */ + reinit_completion(&fsvq->in_flight_zero); + spin_unlock(&fsvq->lock); + wait_for_completion(&fsvq->in_flight_zero); + } else { spin_unlock(&fsvq->lock); - /* TODO use completion instead of timeout */ - usleep_range(1000, 2000); } flush_work(&fsvq->done_work); flush_delayed_work(&fsvq->dispatch_work); } -static void virtio_fs_drain_all_queues(struct virtio_fs *fs) +static void virtio_fs_drain_all_queues_locked(struct virtio_fs *fs) { struct virtio_fs_vq *fsvq; int i; @@ -141,6 +145,19 @@ static void virtio_fs_drain_all_queues(struct virtio_fs *fs) } } +static void virtio_fs_drain_all_queues(struct virtio_fs *fs) +{ + /* Provides mutual exclusion between ->remove and ->kill_sb + * paths. We don't want both of these draining queue at the + * same time. Current completion logic reinits completion + * and that means there should not be any other thread + * doing reinit or waiting for completion already. + */ + mutex_lock(&virtio_fs_mutex); + virtio_fs_drain_all_queues_locked(fs); + mutex_unlock(&virtio_fs_mutex); +} + static void virtio_fs_start_all_queues(struct virtio_fs *fs) { struct virtio_fs_vq *fsvq; @@ -581,6 +598,7 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev, INIT_LIST_HEAD(&fs->vqs[VQ_HIPRIO].end_reqs); INIT_DELAYED_WORK(&fs->vqs[VQ_HIPRIO].dispatch_work, virtio_fs_hiprio_dispatch_work); + init_completion(&fs->vqs[VQ_HIPRIO].in_flight_zero); spin_lock_init(&fs->vqs[VQ_HIPRIO].lock); /* Initialize the requests virtqueues */ @@ -591,6 +609,7 @@ static int virtio_fs_setup_vqs(struct virtio_device *vdev, virtio_fs_request_dispatch_work); INIT_LIST_HEAD(&fs->vqs[i].queued_reqs); INIT_LIST_HEAD(&fs->vqs[i].end_reqs); + init_completion(&fs->vqs[i].in_flight_zero); snprintf(fs->vqs[i].name, sizeof(fs->vqs[i].name), "requests.%u", i - VQ_REQUEST); callbacks[i] = virtio_fs_vq_done; @@ -684,7 +703,7 @@ static void virtio_fs_remove(struct virtio_device *vdev) /* This device is going away. No one should get new reference */ list_del_init(&fs->list); virtio_fs_stop_all_queues(fs); - virtio_fs_drain_all_queues(fs); + virtio_fs_drain_all_queues_locked(fs); vdev->config->reset(vdev); virtio_fs_cleanup_vqs(vdev, fs);