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spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35778 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hv4kL-0001jB-D8 for qemu-devel@archiver.kernel.org; Tue, 06 Aug 2019 15:03:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41390) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hv4f6-0007tk-H6 for qemu-devel@nongnu.org; Tue, 06 Aug 2019 14:58:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hv4f5-0007gM-CF for qemu-devel@nongnu.org; Tue, 06 Aug 2019 14:58:20 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50303) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hv4f5-0007fE-40 for qemu-devel@nongnu.org; Tue, 06 Aug 2019 14:58:19 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D224A51EF4; Tue, 6 Aug 2019 18:58:17 +0000 (UTC) Received: from work-vm (ovpn-117-206.ams2.redhat.com [10.36.117.206]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8E8E860A9D; Tue, 6 Aug 2019 18:58:12 +0000 (UTC) Date: Tue, 6 Aug 2019 19:58:09 +0100 From: "Dr. David Alan Gilbert" To: Stefan Hajnoczi Message-ID: <20190806185809.GA12301@work-vm> References: <20190801165409.20121-1-stefanha@redhat.com> <20190801165409.20121-4-stefanha@redhat.com> <20190805151708.GN13734@work-vm> <20190805185751.GB17658@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190805185751.GB17658@work-vm> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 06 Aug 2019 18:58:18 +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" * Dr. David Alan Gilbert (dgilbert@redhat.com) wrote: > * Dr. David Alan Gilbert (dgilbert@redhat.com) wrote: > > * 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); > > I'm seeing a crash here if I ctrl-c the virtiofsd after it's got an > active mount: > > (process:3219): GLib-CRITICAL **: 18:42:08.334: g_hash_table_foreach_remove_or_steal: assertion 'version == hash_table->version' failed > > (I only get the debug if I give seccomp both getpeername and ioctl; > I think glib is trying to get to syslog and wants getpeername > and I'm guessing ioctl to do something funky with the terminal). That's also the culprit for a crash on umount that only happens with -o cache=auto - reverting this makes it go away. Dave > Dave > > > > } > > > > > > static struct fuse_lowlevel_ops lo_oper = { > > > -- > > > 2.21.0 > > > > > -- > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK