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 331EFC46467 for ; Mon, 16 Jan 2023 16:27:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233003AbjAPQ1k (ORCPT ); Mon, 16 Jan 2023 11:27:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233081AbjAPQ1H (ORCPT ); Mon, 16 Jan 2023 11:27:07 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F5412B602 for ; Mon, 16 Jan 2023 08:15:31 -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 F0BAD6102D for ; Mon, 16 Jan 2023 16:15:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E1C3C433D2; Mon, 16 Jan 2023 16:15:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673885730; bh=be3ztIYek4JY2cj47i/qh0cPB9DRefWekteKmXOA7iI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yL450ouDQN5h0dcW9GO1a/Ccq4x6gDLcRQhbJMHCCBVa+0hO8MzuDHEfSeGw0/5p+ NmxwEqU8hOLc3lBVGtg+EDNFw71J2H6r9CnxjwQn06WI77/s4RzAOWFDtIAOi6zmuY etN8rOBu/TD3TttrD8zzNpeek6QgfKg8X98cb4Ms= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Trond Myklebust , Sasha Levin Subject: [PATCH 5.4 163/658] NFSv4: Fix a deadlock between nfs4_open_recover_helper() and delegreturn Date: Mon, 16 Jan 2023 16:44:11 +0100 Message-Id: <20230116154916.922921554@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154909.645460653@linuxfoundation.org> References: <20230116154909.645460653@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: Trond Myklebust [ Upstream commit 51069e4aef6257b0454057359faed0ab0c9af083 ] If we're asked to recover open state while a delegation return is outstanding, then the state manager thread cannot use a cached open, so if the server returns a delegation, we can end up deadlocked behind the pending delegreturn. To avoid this problem, let's just ask the server not to give us a delegation unless we're explicitly reclaiming one. Fixes: be36e185bd26 ("NFSv4: nfs4_open_recover_helper() must set share access") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/nfs4proc.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 3da48dd67b83..a76550d927e7 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2085,18 +2085,18 @@ static struct nfs4_opendata *nfs4_open_recoverdata_alloc(struct nfs_open_context } static int nfs4_open_recover_helper(struct nfs4_opendata *opendata, - fmode_t fmode) + fmode_t fmode) { struct nfs4_state *newstate; + struct nfs_server *server = NFS_SB(opendata->dentry->d_sb); + int openflags = opendata->o_arg.open_flags; int ret; if (!nfs4_mode_match_open_stateid(opendata->state, fmode)) return 0; - opendata->o_arg.open_flags = 0; opendata->o_arg.fmode = fmode; - opendata->o_arg.share_access = nfs4_map_atomic_open_share( - NFS_SB(opendata->dentry->d_sb), - fmode, 0); + opendata->o_arg.share_access = + nfs4_map_atomic_open_share(server, fmode, openflags); memset(&opendata->o_res, 0, sizeof(opendata->o_res)); memset(&opendata->c_res, 0, sizeof(opendata->c_res)); nfs4_init_opendata_res(opendata); @@ -2671,10 +2671,15 @@ static int _nfs4_open_expired(struct nfs_open_context *ctx, struct nfs4_state *s struct nfs4_opendata *opendata; int ret; - opendata = nfs4_open_recoverdata_alloc(ctx, state, - NFS4_OPEN_CLAIM_FH); + opendata = nfs4_open_recoverdata_alloc(ctx, state, NFS4_OPEN_CLAIM_FH); if (IS_ERR(opendata)) return PTR_ERR(opendata); + /* + * We're not recovering a delegation, so ask for no delegation. + * Otherwise the recovery thread could deadlock with an outstanding + * delegation return. + */ + opendata->o_arg.open_flags = O_DIRECT; ret = nfs4_open_recover(opendata, state); if (ret == -ESTALE) d_drop(ctx->dentry); -- 2.35.1