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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 5F95BC00307 for ; Fri, 6 Sep 2019 13:36:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4450320650 for ; Fri, 6 Sep 2019 13:36:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405132AbfIFNgE (ORCPT ); Fri, 6 Sep 2019 09:36:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38281 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391482AbfIFNgE (ORCPT ); Fri, 6 Sep 2019 09:36:04 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 821DD301D67F; Fri, 6 Sep 2019 13:36:03 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.137]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8D2CF1001947; Fri, 6 Sep 2019 13:35:55 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 1F167220292; Fri, 6 Sep 2019 09:35:55 -0400 (EDT) Date: Fri, 6 Sep 2019 09:35:55 -0400 From: Vivek Goyal To: Stefan Hajnoczi Cc: linux-fsdevel@vger.kernel.org, virtualization@lists.linux-foundation.org, miklos@szeredi.hu, linux-kernel@vger.kernel.org, virtio-fs@redhat.com, dgilbert@redhat.com, mst@redhat.com Subject: Re: [PATCH 14/18] virtiofs: Add a fuse_iqueue operation to put() reference Message-ID: <20190906133555.GC22083@redhat.com> References: <20190905194859.16219-1-vgoyal@redhat.com> <20190905194859.16219-15-vgoyal@redhat.com> <20190906120009.GV5900@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190906120009.GV5900@stefanha-x1.localdomain> User-Agent: Mutt/1.12.0 (2019-05-25) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Fri, 06 Sep 2019 13:36:03 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Sep 06, 2019 at 01:00:09PM +0100, Stefan Hajnoczi wrote: > On Thu, Sep 05, 2019 at 03:48:55PM -0400, Vivek Goyal wrote: > > diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h > > index 85e2dcad68c1..04e2c000d63f 100644 > > --- a/fs/fuse/fuse_i.h > > +++ b/fs/fuse/fuse_i.h > > @@ -479,6 +479,11 @@ struct fuse_iqueue_ops { > > */ > > void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq) > > __releases(fiq->waitq.lock); > > + > > + /** > > + * Put a reference on fiq_priv. > > I'm a bit confused about fiq->priv's role in this. The callback takes > struct fuse_iqueue *fiq as the argument, not void *priv, so it could > theoretically do more than just release priv. > > I think one of the following would be clearer: > > /** > * Drop a reference to fiq->priv. > */ > void (*put_priv)(void *priv); > > Or: > > /** > * Clean up when fuse_iqueue is destroyed. > */ > void (*release)(struct fuse_iqueue *fiq); > > In the second case fuse_conn_put() shouldn't check fiq->priv. Hi Stefan, I like using ->release() method sounds better. Here is the updated patch. This also changes the next patch, so will post that as well. Thanks Vivek Subject: virtiofs: Add a fuse_iqueue operation to put() reference Soon I will make virtio_fs object reference counted, where reference will be taken by device as well as by fuse_conn (fuse_conn->fuse_iqueue->fiq_priv). When fuse_connection is going away, it should put its reference on virtio_fs object. So add a fuse_iqueue method which can be used to call into virtio_fs to put the reference on the object (fiq_priv). Signed-off-by: Vivek Goyal --- fs/fuse/fuse_i.h | 5 +++++ fs/fuse/inode.c | 4 ++++ 2 files changed, 9 insertions(+) Index: rhvgoyal-linux-fuse/fs/fuse/fuse_i.h =================================================================== --- rhvgoyal-linux-fuse.orig/fs/fuse/fuse_i.h 2019-09-06 08:46:41.846086544 -0400 +++ rhvgoyal-linux-fuse/fs/fuse/fuse_i.h 2019-09-06 09:24:32.752245246 -0400 @@ -479,6 +479,11 @@ struct fuse_iqueue_ops { */ void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq) __releases(fiq->waitq.lock); + + /** + * Cleanup up when fuse_iqueue is destroyed + */ + void (*release)(struct fuse_iqueue *fiq); }; /** /dev/fuse input queue operations */ Index: rhvgoyal-linux-fuse/fs/fuse/inode.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/fuse/inode.c 2019-09-06 08:46:41.847086544 -0400 +++ rhvgoyal-linux-fuse/fs/fuse/inode.c 2019-09-06 09:24:32.754245246 -0400 @@ -631,8 +631,12 @@ EXPORT_SYMBOL_GPL(fuse_conn_init); void fuse_conn_put(struct fuse_conn *fc) { if (refcount_dec_and_test(&fc->count)) { + struct fuse_iqueue *fiq = &fc->iq; + if (fc->destroy_req) fuse_request_free(fc->destroy_req); + if (fiq->ops->release) + fiq->ops->release(fiq); put_pid_ns(fc->pid_ns); put_user_ns(fc->user_ns); fc->release(fc);