From patchwork Wed Aug 23 21:33:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Aring X-Patchwork-Id: 13363157 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95F32C7113B for ; Wed, 23 Aug 2023 21:36:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238064AbjHWVfv (ORCPT ); Wed, 23 Aug 2023 17:35:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238035AbjHWVfU (ORCPT ); Wed, 23 Aug 2023 17:35:20 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 16CA010E5 for ; Wed, 23 Aug 2023 14:34:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692826440; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=htB9ruBs/M3gzRN+MQhu18/VcxVtJfis4P4SxexSrGE=; b=FB4OZnpeWlvLrIbyUoWyFWcZyidEwyej6Q31rWceM4PKq8B8tJ8iJZOHO+b2uP+tEZrf27 9L+ZNWBhwlrjwTwQ/y5CiDKAYcCPtNP5IpGUIMlUKFXfbgB9aGwEbUgvONtS8g/N4St/yO KHJ0K/AGQgABDWSB4PBpweiC6KjQ5Yc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-454-j9OrqPG9M-uKAhTJKw2f4g-1; Wed, 23 Aug 2023 17:33:54 -0400 X-MC-Unique: j9OrqPG9M-uKAhTJKw2f4g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 60E94185A78B; Wed, 23 Aug 2023 21:33:54 +0000 (UTC) Received: from fs-i40c-03.fs.lab.eng.bos.redhat.com (fs-i40c-03.fs.lab.eng.bos.redhat.com [10.16.224.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1971640C6F4C; Wed, 23 Aug 2023 21:33:54 +0000 (UTC) From: Alexander Aring To: linux-nfs@vger.kernel.org Cc: cluster-devel@redhat.com, ocfs2-devel@lists.linux.dev, linux-fsdevel@vger.kernel.org, teigland@redhat.com, rpeterso@redhat.com, agruenba@redhat.com, trond.myklebust@hammerspace.com, anna@kernel.org, chuck.lever@oracle.com, jlayton@kernel.org Subject: [PATCH 2/7] lockd: don't call vfs_lock_file() for pending requests Date: Wed, 23 Aug 2023 17:33:47 -0400 Message-Id: <20230823213352.1971009-3-aahringo@redhat.com> In-Reply-To: <20230823213352.1971009-1-aahringo@redhat.com> References: <20230823213352.1971009-1-aahringo@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org This patch returns nlm_lck_blocked in nlmsvc_lock() when an asynchronous lock request is pending. During testing I ran into the case with the side-effects that lockd is waiting for only one lm_grant() callback because it's already part of the nlm_blocked list. If another asynchronous for the same nlm_block is triggered two lm_grant() callbacks will occur but lockd was only waiting for one. To avoid any change of existing users this handling will only being made when export_op_support_safe_async_lock() returns true. Signed-off-by: Alexander Aring Reviewed-by: Jeff Layton --- fs/lockd/svclock.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index 6e3b230e8317..aa4174fbaf5b 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -531,6 +531,23 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, goto out; } + spin_lock(&nlm_blocked_lock); + /* + * If this is a lock request for an already pending + * lock request we return nlm_lck_blocked without calling + * vfs_lock_file() again. Otherwise we have two pending + * requests on the underlaying ->lock() implementation but + * only one nlm_block to being granted by lm_grant(). + */ + if (export_op_support_safe_async_lock(inode->i_sb->s_export_op, + nlmsvc_file_file(file)->f_op) && + !list_empty(&block->b_list)) { + spin_unlock(&nlm_blocked_lock); + ret = nlm_lck_blocked; + goto out; + } + spin_unlock(&nlm_blocked_lock); + if (!wait) lock->fl.fl_flags &= ~FL_SLEEP; mode = lock_to_openmode(&lock->fl); @@ -543,13 +560,6 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, ret = nlm_granted; goto out; case -EAGAIN: - /* - * If this is a blocking request for an - * already pending lock request then we need - * to put it back on lockd's block list - */ - if (wait) - break; ret = async_block ? nlm_lck_blocked : nlm_lck_denied; goto out; case FILE_LOCK_DEFERRED: