From patchwork Mon Mar 4 06:31:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 10837379 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A3F4A1575 for ; Mon, 4 Mar 2019 06:35:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8F1AE289BC for ; Mon, 4 Mar 2019 06:35:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 833CC29DAD; Mon, 4 Mar 2019 06:35:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from pdx1-mailman02.dreamhost.com (pdx1-mailman02.dreamhost.com [64.90.62.194]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3BAD229D0C for ; Mon, 4 Mar 2019 06:35:59 +0000 (UTC) Received: from pdx1-mailman02.dreamhost.com (localhost [IPv6:::1]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id DF902682795; Sun, 3 Mar 2019 22:35:58 -0800 (PST) X-Original-To: lustre-devel@lists.lustre.org Delivered-To: lustre-devel-lustre.org@pdx1-mailman02.dreamhost.com Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id EA61B6829AE for ; Sun, 3 Mar 2019 22:35:56 -0800 (PST) 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 28F9DAC9C; Mon, 4 Mar 2019 06:35:56 +0000 (UTC) From: NeilBrown To: Andreas Dilger , James Simmons , Oleg Drokin Date: Mon, 04 Mar 2019 17:31:39 +1100 Message-ID: <155168109899.31333.4089899412651911583.stgit@noble.brown> In-Reply-To: <155168107971.31333.14345309795939467246.stgit@noble.brown> References: <155168107971.31333.14345309795939467246.stgit@noble.brown> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Subject: [lustre-devel] [PATCH 25/28] lustre: ldlm: don't access l_resource when not locked. X-BeenThere: lustre-devel@lists.lustre.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "For discussing Lustre software development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lustre Development List Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" X-Virus-Scanned: ClamAV using ClamSMTP lock->l_resource can (sometimes) change when the resource isn't locked. So dereferencing lock->l_resource and the locking the resource looks wrong. As lock_res_and_lock() returns the locked resource, this code can easily be more obviously correct by using that return value. Signed-off-by: NeilBrown --- drivers/staging/lustre/lustre/ldlm/ldlm_lock.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c b/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c index e62dad14d822..830d089774a3 100644 --- a/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_lock.c @@ -425,13 +425,13 @@ static struct ldlm_lock *ldlm_lock_new(struct ldlm_resource *resource) int ldlm_lock_change_resource(struct ldlm_namespace *ns, struct ldlm_lock *lock, const struct ldlm_res_id *new_resid) { - struct ldlm_resource *oldres = lock->l_resource; + struct ldlm_resource *oldres; struct ldlm_resource *newres; int type; - lock_res_and_lock(lock); - if (memcmp(new_resid, &lock->l_resource->lr_name, - sizeof(lock->l_resource->lr_name)) == 0) { + oldres = lock_res_and_lock(lock); + if (memcmp(new_resid, &oldres->lr_name, + sizeof(oldres->lr_name)) == 0) { /* Nothing to do */ unlock_res_and_lock(lock); return 0; @@ -1573,9 +1573,9 @@ enum ldlm_error ldlm_lock_enqueue(struct ldlm_namespace *ns, void *cookie, u64 *flags) { struct ldlm_lock *lock = *lockp; - struct ldlm_resource *res = lock->l_resource; + struct ldlm_resource *res; - lock_res_and_lock(lock); + res = lock_res_and_lock(lock); if (lock->l_req_mode == lock->l_granted_mode) { /* The server returned a blocked lock, but it was granted * before we got a chance to actually enqueue it. We don't @@ -1874,9 +1874,8 @@ void ldlm_lock_cancel(struct ldlm_lock *lock) struct ldlm_resource *res; struct ldlm_namespace *ns; - lock_res_and_lock(lock); + res = lock_res_and_lock(lock); - res = lock->l_resource; ns = ldlm_res_to_ns(res); /* Please do not, no matter how tempting, remove this LBUG without