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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 2915BC10F03 for ; Wed, 24 Apr 2019 02:00:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1862218D3 for ; Wed, 24 Apr 2019 02:00:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727085AbfDXCAR (ORCPT ); Tue, 23 Apr 2019 22:00:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:42098 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726461AbfDXCAR (ORCPT ); Tue, 23 Apr 2019 22:00:17 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 4B8CDAC3A; Wed, 24 Apr 2019 02:00:16 +0000 (UTC) From: NeilBrown To: Jeff Layton Date: Wed, 24 Apr 2019 12:00:08 +1000 Cc: Bruce Fields , slawek1211@gmail.com, "open list\:NFS\, SUNRPC\, AND..." Subject: [PATCH] locks: move checks from locks_free_lock() to locks_release_private() In-Reply-To: References: <20190422163424.19402-1-jlayton@kernel.org> <20190422163424.19402-2-jlayton@kernel.org> <87wojl61s5.fsf@notabene.neil.brown.name> Message-ID: <87r29s5fiv.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Code that allocates locks using locks_alloc_lock() will free it using locks_free_lock(), and will benefit from the BUG_ON() consistency checks therein. However some code (nfsd and lockd) allocate a lock embedded in some other data structure, and so free the lock themselves after calling locks_release_private(). This path does not benefit from the consistency checks. To help catch future errors, move the BUG_ON() checks to locks_release_private() - which locks_free_lock() already calls. This ensures that all users for locks will find out if the lock isn't detached properly before being free. Signed-off-by: NeilBrown =2D-- fs/locks.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 71d0c6c2aac5..456a3782c6ca 100644 =2D-- a/fs/locks.c +++ b/fs/locks.c @@ -352,6 +352,12 @@ EXPORT_SYMBOL_GPL(locks_alloc_lock); =20 void locks_release_private(struct file_lock *fl) { + BUG_ON(waitqueue_active(&fl->fl_wait)); + BUG_ON(!list_empty(&fl->fl_list)); + BUG_ON(!list_empty(&fl->fl_blocked_requests)); + BUG_ON(!list_empty(&fl->fl_blocked_member)); + BUG_ON(!hlist_unhashed(&fl->fl_link)); + if (fl->fl_ops) { if (fl->fl_ops->fl_release_private) fl->fl_ops->fl_release_private(fl); @@ -371,12 +377,6 @@ EXPORT_SYMBOL_GPL(locks_release_private); /* Free a lock which is not in use. */ void locks_free_lock(struct file_lock *fl) { =2D BUG_ON(waitqueue_active(&fl->fl_wait)); =2D BUG_ON(!list_empty(&fl->fl_list)); =2D BUG_ON(!list_empty(&fl->fl_blocked_requests)); =2D BUG_ON(!list_empty(&fl->fl_blocked_member)); =2D BUG_ON(!hlist_unhashed(&fl->fl_link)); =2D locks_release_private(fl); kmem_cache_free(filelock_cache, fl); } =2D-=20 2.14.0.rc0.dirty --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAly/wygACgkQOeye3VZi gbm98A//dJd3a9vasGk3V/zAjeu9zlBjxlNEfESnJVjj9EwHXIEF7w+2Si7lNiHD NKfJhW5AHctAUx3UwzNZSDgT5JUNs4QR6GRK5EaZXvp5reDEIsL4aA4W9nfqGob6 PH+X5DFydpBy+nwxBHjmu6bc9NEvkpRwVyzfEZWPSzdc7WgHwe0rDkHi3GTZSfh/ 3MKYBc/j31mAfReDkMakGZrh5fIpegI4+PaYnN9638lRKQLIDX3kXwXzGVqqk8VE rcko5tbypCTt1icCoPV/S9y3dbq6+x6Jy/S9OT+K/4TP5vXGbAiMUlOtAxgAMdiW KuwESC48Ajy0W5VBXnLNGc3a17NCHjOicNjhsXLLTQch3uzVpDv/8BRHP+R9KZ/d HOPjON/aaxfSePzKVbEBuGWFdjeOEh2ijJfpkevwLxqbRQ3X1NbkmueTLfeDUIeK 0CvKg0wt6qwx4xmWZnMqjduhQyvjXXq0njw4RjQvRsaBkx39hV76JOnRbjpcVPkZ XCSMvPPpwPYMypPy279OD3LQToJLbBZTWxHOoXnpofc96ULBmURlXrEP4uT51Eo2 Zi5k2RQTVZTRNjlu6sKTRE95WXXNbrIFoNNwroYi0HSdtos6uia2HJ4e0Y4iZjLV aSIc2GWEanAsJSoGSzGGkxAO1TUbFScP/pL0xFUC2icr+C4SoKU= =upqO -----END PGP SIGNATURE----- --=-=-=--