From mboxrd@z Thu Jan 1 00:00:00 1970 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 CCFD3C6FD1A for ; Tue, 7 Mar 2023 17:33:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231705AbjCGRdQ (ORCPT ); Tue, 7 Mar 2023 12:33:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231682AbjCGRcu (ORCPT ); Tue, 7 Mar 2023 12:32:50 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3517C8482A for ; Tue, 7 Mar 2023 09:28:33 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C13C86150C for ; Tue, 7 Mar 2023 17:28:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5CACC433EF; Tue, 7 Mar 2023 17:28:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678210112; bh=bPidgu5Mn4F6JXnlGpJzBju1CCgh/IdAdrSNXD8Kpa8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sQAKcUadP+GqM0QwrABiOWcA8LvMEQW6gnm/We73nfTYvLzrwWD/VYxXq6LHVpEgk O6y2qx5Wci/Xa/SLIG7pAmrJ3k42FDXpyVqxZ626dMo/1uvrd3oVTlELjLon116usX zhQ2y3NEO9hpsda3Fy8XXtanBkf54WublNjZsp0Q= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Olga Kornievskaia , NeilBrown , Anna Schumaker , Sasha Levin Subject: [PATCH 6.2 0437/1001] NFS: fix disabling of swap Date: Tue, 7 Mar 2023 17:53:29 +0100 Message-Id: <20230307170040.319549230@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: NeilBrown [ Upstream commit 5bab56fff53ce161ed859d9559a10361d4f79578 ] When swap is activated to a file on an NFSv4 mount we arrange that the state manager thread is always present as starting a new thread requires memory allocations that might block waiting for swap. Unfortunately the code for allowing the state manager thread to exit when swap is disabled was not tested properly and does not work. This can be seen by examining /proc/fs/nfsfs/servers after disabling swap and unmounting the filesystem. The servers file will still list one entry. Also a "ps" listing will show the state manager thread is still present. There are two problems. 1/ rpc_clnt_swap_deactivate() doesn't walk up the ->cl_parent list to find the primary client on which the state manager runs. 2/ The thread is not woken up properly and it immediately goes back to sleep without checking whether it is really needed. Using nfs4_schedule_state_manager() ensures a proper wake-up. Reported-by: Olga Kornievskaia Fixes: 4dc73c679114 ("NFSv4: keep state manager thread active if swap is enabled") Signed-off-by: NeilBrown Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin --- fs/nfs/nfs4proc.c | 4 +++- net/sunrpc/clnt.c | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 40d749f29ed3f..4214286e01450 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -10604,7 +10604,9 @@ static void nfs4_disable_swap(struct inode *inode) /* The state manager thread will now exit once it is * woken. */ - wake_up_var(&NFS_SERVER(inode)->nfs_client->cl_state); + struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; + + nfs4_schedule_state_manager(clp); } static const struct inode_operations nfs4_dir_inode_operations = { diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 0b0b9f1eed469..fd7e1c630493e 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -3350,6 +3350,8 @@ rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt, void rpc_clnt_swap_deactivate(struct rpc_clnt *clnt) { + while (clnt != clnt->cl_parent) + clnt = clnt->cl_parent; if (atomic_dec_if_positive(&clnt->cl_swapper) == 0) rpc_clnt_iterate_for_each_xprt(clnt, rpc_clnt_swap_deactivate_callback, NULL); -- 2.39.2