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spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54788 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1huekn-0004EU-Mw for qemu-devel@archiver.kernel.org; Mon, 05 Aug 2019 11:18:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49570) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hueji-0003Wg-77 for qemu-devel@nongnu.org; Mon, 05 Aug 2019 11:17:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1huejf-0001nP-HE for qemu-devel@nongnu.org; Mon, 05 Aug 2019 11:17:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33860) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1huejd-0001mQ-Sf for qemu-devel@nongnu.org; Mon, 05 Aug 2019 11:17:18 -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 2F41B368DA; Mon, 5 Aug 2019 15:17:17 +0000 (UTC) Received: from work-vm (ovpn-117-168.ams2.redhat.com [10.36.117.168]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2704E10016EA; Mon, 5 Aug 2019 15:17:10 +0000 (UTC) Date: Mon, 5 Aug 2019 16:17:08 +0100 From: "Dr. David Alan Gilbert" To: Stefan Hajnoczi Message-ID: <20190805151708.GN13734@work-vm> References: <20190801165409.20121-1-stefanha@redhat.com> <20190801165409.20121-4-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190801165409.20121-4-stefanha@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) 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 [10.5.110.30]); Mon, 05 Aug 2019 15:17:17 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 3/4] virtiofsd: fix lo_destroy() resource leaks 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: virtio-fs@redhat.com, Liu Bo , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Stefan Hajnoczi (stefanha@redhat.com) wrote: > Now that lo_destroy() is serialized we can call unref_inode() so that > all inode resources are freed. > > Signed-off-by: Stefan Hajnoczi Reviewed-by: Dr. David Alan Gilbert > --- > contrib/virtiofsd/passthrough_ll.c | 43 ++++++++++++++---------------- > 1 file changed, 20 insertions(+), 23 deletions(-) > > diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c > index a81c01d0d1..02a5e97326 100644 > --- a/contrib/virtiofsd/passthrough_ll.c > +++ b/contrib/virtiofsd/passthrough_ll.c > @@ -1340,28 +1340,6 @@ static void unref_inode(struct lo_data *lo, struct lo_inode *inode, uint64_t n) > } > } > > -static int unref_all_inodes_cb(gpointer key, gpointer value, > - gpointer user_data) > -{ > - struct lo_inode *inode = value; > - struct lo_data *lo = user_data; > - > - inode->nlookup = 0; > - lo_map_remove(&lo->ino_map, inode->fuse_ino); > - close(inode->fd); > - lo_inode_put(lo, &inode); /* Drop our refcount from lo_do_lookup() */ > - > - return TRUE; > -} > - > -static void unref_all_inodes(struct lo_data *lo) > -{ > - pthread_mutex_lock(&lo->mutex); > - g_hash_table_foreach_remove(lo->inodes, unref_all_inodes_cb, lo); > - pthread_mutex_unlock(&lo->mutex); > - > -} > - > static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) > { > struct lo_data *lo = lo_data(req); > @@ -2462,6 +2440,18 @@ static void lo_removemapping(fuse_req_t req, struct fuse_session *se, > fuse_reply_err(req, ret); > } > > +static int destroy_inode_cb(gpointer key, gpointer value, gpointer user_data) > +{ > + struct lo_inode *inode = value; > + struct lo_data *lo = user_data; > + > + /* inode->nlookup is normally protected by lo->mutex but see the > + * comment in lo_destroy(). > + */ > + unref_inode(lo, inode, inode->nlookup); > + return TRUE; > +} > + > static void lo_destroy(void *userdata, struct fuse_session *se) > { > struct lo_data *lo = (struct lo_data*) userdata; > @@ -2475,7 +2465,14 @@ static void lo_destroy(void *userdata, struct fuse_session *se) > fuse_err("%s: unmap during destroy failed\n", __func__); > } > } > - unref_all_inodes(lo); > + > + /* Normally lo->mutex must be taken when traversing lo->inodes but > + * lo_destroy() is a serialized request so no races are possible here. > + * > + * In addition, we cannot acquire lo->mutex since destroy_inode_cb() takes it > + * too and this would result in a recursive lock. > + */ > + g_hash_table_foreach_remove(lo->inodes, destroy_inode_cb, lo); > } > > static struct fuse_lowlevel_ops lo_oper = { > -- > 2.21.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK