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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B850C433F5 for ; Mon, 4 Oct 2021 13:15:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44CFF63229 for ; Mon, 4 Oct 2021 13:15:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235914AbhJDNQs (ORCPT ); Mon, 4 Oct 2021 09:16:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:31626 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235903AbhJDNOq (ORCPT ); Mon, 4 Oct 2021 09:14:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633353177; 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: in-reply-to:in-reply-to:references:references; bh=nKy01q7QzviKlAmThKzHSK4Bhyjv5rNTrVc1mM+/eWA=; b=W/06WMdChXuj3ST6mH6+TaPyMI9BqkXViAUcvmGjwTp5dfRsEgpl118pG/eDGRvj8ZIJAr jjikMEGgL7QB4J1W4wXHhszEydWVgJKmHSdWRRSOd5Er5liLLoGOgueY9d93zVg4V9GKy1 MW15Mh9wTT5DBK+gOTFQ6SwUmQqAHV0= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-419-Ik-wAsqmMFWjbYjvE1829A-1; Mon, 04 Oct 2021 09:12:56 -0400 X-MC-Unique: Ik-wAsqmMFWjbYjvE1829A-1 Received: by mail-wr1-f70.google.com with SMTP id x14-20020a5d60ce000000b00160b27b5fd1so296637wrt.5 for ; Mon, 04 Oct 2021 06:12:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=nKy01q7QzviKlAmThKzHSK4Bhyjv5rNTrVc1mM+/eWA=; b=oe4VOFLaakBlOB0beRPPVRDsTZpbwDC4Y/K0gv9mdPFOaX7o4Ow+pOqRXqbKkBw1Nr iL5+MOHEBYSPYNh+0aCyIHQ9DSI/7XObrhO2o8/iRKXk4sPKvDmLubPy80mqk6Fo7flR x4J6rI7Q7kZ2mApH2K8jKmevcAKJx8LiXZamKCwteg3U1FdtCZ4YLSNLCTB18i/Z7jhp iRr1S/yZSfFc+pLWFgwbqRD3BeFMGclri1DG8QiKHJhjaQGaS6II4AWqrDSlhd2BUv6s kshiL6fmkW+n51J7bltGKahEJGTBktY4bUqScUPO4KErgESukARCXYGLMNvzTyAaJraX Cvvg== X-Gm-Message-State: AOAM533ErM8OdF1jjpJcno5k40AOjCub2McwtlS4SY0b4JLgr/ORpktb ASwEahJz95ZFIwIPj5vmVPAgUcSw60tqpLqWhTMdwI1p0C9ldmhDWqU7MoAo+1SKwK3A189t4Wu eutrOxKrdfezU3/5C6pCOGQih X-Received: by 2002:a7b:cde8:: with SMTP id p8mr18259711wmj.160.1633353173565; Mon, 04 Oct 2021 06:12:53 -0700 (PDT) X-Google-Smtp-Source: ABdhPJw/7JuPoRusQE9dAIOzDjog1WyyGeLCBRPdpk0zlyBG1OwcmknElq3co39nZNsk8nASzG7jSQ== X-Received: by 2002:a7b:cde8:: with SMTP id p8mr18259681wmj.160.1633353173364; Mon, 04 Oct 2021 06:12:53 -0700 (PDT) Received: from redhat.com ([2.55.134.94]) by smtp.gmail.com with ESMTPSA id s3sm14366860wrm.40.2021.10.04.06.12.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Oct 2021 06:12:52 -0700 (PDT) Date: Mon, 4 Oct 2021 09:12:49 -0400 From: "Michael S. Tsirkin" To: Mike Christie Cc: hdanton@sina.com, hch@infradead.org, stefanha@redhat.com, jasowang@redhat.com, sgarzare@redhat.com, virtualization@lists.linux-foundation.org, christian.brauner@ubuntu.com, axboe@kernel.dk, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2 9/9] vhost: use kernel_worker to check RLIMITs and inherit v2 cgroups Message-ID: <20211004091216-mutt-send-email-mst@kernel.org> References: <20210921215218.89844-1-michael.christie@oracle.com> <20210921215218.89844-10-michael.christie@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210921215218.89844-10-michael.christie@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 21, 2021 at 04:52:18PM -0500, Mike Christie wrote: > For vhost workers we use the kthread API which inherit's its values from > and checks against the kthreadd thread. This results in cgroups v2 not > working and the wrong RLIMITs being checked. This patch has us use the > kernel_copy_process function which will inherit its values/checks from the > thread that owns the device. > > Signed-off-by: Mike Christie Acked-by: Michael S. Tsirkin Feel free to merge with other bits. > --- > drivers/vhost/vhost.c | 68 ++++++++++++++++--------------------------- > drivers/vhost/vhost.h | 7 ++++- > 2 files changed, 31 insertions(+), 44 deletions(-) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index c9a1f706989c..7a5142dcde1b 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -22,7 +22,6 @@ > #include > #include > #include > -#include > #include > #include > #include > @@ -344,17 +343,14 @@ static void vhost_vq_reset(struct vhost_dev *dev, > static int vhost_worker(void *data) > { > struct vhost_worker *worker = data; > - struct vhost_dev *dev = worker->dev; > struct vhost_work *work, *work_next; > struct llist_node *node; > > - kthread_use_mm(dev->mm); > - > for (;;) { > /* mb paired w/ kthread_stop */ > set_current_state(TASK_INTERRUPTIBLE); > > - if (kthread_should_stop()) { > + if (test_bit(VHOST_WORKER_FLAG_STOP, &worker->flags)) { > __set_current_state(TASK_RUNNING); > break; > } > @@ -376,8 +372,9 @@ static int vhost_worker(void *data) > schedule(); > } > } > - kthread_unuse_mm(dev->mm); > - return 0; > + > + complete(worker->exit_done); > + do_exit(0); > } > > static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq) > @@ -517,31 +514,6 @@ long vhost_dev_check_owner(struct vhost_dev *dev) > } > EXPORT_SYMBOL_GPL(vhost_dev_check_owner); > > -struct vhost_attach_cgroups_struct { > - struct vhost_work work; > - struct task_struct *owner; > - int ret; > -}; > - > -static void vhost_attach_cgroups_work(struct vhost_work *work) > -{ > - struct vhost_attach_cgroups_struct *s; > - > - s = container_of(work, struct vhost_attach_cgroups_struct, work); > - s->ret = cgroup_attach_task_all(s->owner, current); > -} > - > -static int vhost_attach_cgroups(struct vhost_dev *dev) > -{ > - struct vhost_attach_cgroups_struct attach; > - > - attach.owner = current; > - vhost_work_init(&attach.work, vhost_attach_cgroups_work); > - vhost_work_queue(dev, &attach.work); > - vhost_work_dev_flush(dev); > - return attach.ret; > -} > - > /* Caller should have device mutex */ > bool vhost_dev_has_owner(struct vhost_dev *dev) > { > @@ -579,6 +551,16 @@ static void vhost_detach_mm(struct vhost_dev *dev) > dev->mm = NULL; > } > > +static void vhost_worker_stop(struct vhost_worker *worker) > +{ > + DECLARE_COMPLETION_ONSTACK(exit_done); > + > + worker->exit_done = &exit_done; > + set_bit(VHOST_WORKER_FLAG_STOP, &worker->flags); > + wake_up_process(worker->task); > + wait_for_completion(worker->exit_done); > +} > + > static void vhost_worker_free(struct vhost_dev *dev) > { > struct vhost_worker *worker = dev->worker; > @@ -588,7 +570,7 @@ static void vhost_worker_free(struct vhost_dev *dev) > > dev->worker = NULL; > WARN_ON(!llist_empty(&worker->work_list)); > - kthread_stop(worker->task); > + vhost_worker_stop(worker); > kfree(worker); > } > > @@ -603,27 +585,27 @@ static int vhost_worker_create(struct vhost_dev *dev) > return -ENOMEM; > > dev->worker = worker; > - worker->dev = dev; > worker->kcov_handle = kcov_common_handle(); > init_llist_head(&worker->work_list); > > - task = kthread_create(vhost_worker, worker, "vhost-%d", current->pid); > + /* > + * vhost used to use the kthread API which ignores all signals by > + * default and the drivers expect this behavior. So we do not want to > + * ineherit the parent's signal handlers and set our worker to ignore > + * everything below. > + */ > + task = kernel_worker(vhost_worker, worker, NUMA_NO_NODE, > + CLONE_FS | CLONE_CLEAR_SIGHAND, > + KERN_WORKER_NO_FILES | KERN_WORKER_NO_SIGS); > if (IS_ERR(task)) { > ret = PTR_ERR(task); > goto free_worker; > } > > worker->task = task; > - wake_up_process(task); /* avoid contributing to loadavg */ > - > - ret = vhost_attach_cgroups(dev); > - if (ret) > - goto stop_worker; > - > + kernel_worker_start(task, "vhost-%d", current->pid); > return 0; > > -stop_worker: > - kthread_stop(worker->task); > free_worker: > kfree(worker); > dev->worker = NULL; > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index 102ce25e4e13..09748694cb66 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -25,11 +25,16 @@ struct vhost_work { > unsigned long flags; > }; > > +enum { > + VHOST_WORKER_FLAG_STOP, > +}; > + > struct vhost_worker { > struct task_struct *task; > + struct completion *exit_done; > struct llist_head work_list; > - struct vhost_dev *dev; > u64 kcov_handle; > + unsigned long flags; > }; > > /* Poll a file (eventfd or socket) */ > -- > 2.25.1