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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 99F55C35669 for ; Sun, 23 Feb 2020 02:21:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72CFB20702 for ; Sun, 23 Feb 2020 02:21:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582424503; bh=wW3mnCktbCYmM3gZdL9hrOX6Kz4wm/IgY/aenYoR6z4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YDFOC1OUum//Q/37XSOwuXH/wclgbGLX8d0nVN1vJmhxgjpVYMVuL+gpSmvXMSt4I EEsRfTXCS1bNncyyIhc2W85t0jPw6jzEMekGpmj8JGfhGGmZ4AiE1cm56nyoN095bu mFiB29GzPARdp32DR6XAaImMVqvDCtCtk1XiuvEs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727648AbgBWCVm (ORCPT ); Sat, 22 Feb 2020 21:21:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:50022 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727463AbgBWCVg (ORCPT ); Sat, 22 Feb 2020 21:21:36 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7231D206D7; Sun, 23 Feb 2020 02:21:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582424496; bh=wW3mnCktbCYmM3gZdL9hrOX6Kz4wm/IgY/aenYoR6z4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WQBAbsWzvtMRjXQbTgdX4fDc5GPRQQFng1WapaT/Wvc6IaJjmeg/rkqLkB0igxBNa O9Lzu1VeOL26H2/7WP7JwmwtS/dcZFYoOCsD3VcFCsI8M0RP7n4ZUFd0O6bnEAT8Wc eaRMPCEebJsvL4MXokF3uMLB5bsVFcZPFo2fy9oI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Trond Myklebust , Trond Myklebust , Benjamin Coddington , Anna Schumaker , Sasha Levin , linux-nfs@vger.kernel.org Subject: [PATCH AUTOSEL 5.5 13/58] NFSv4: Fix races between open and dentry revalidation Date: Sat, 22 Feb 2020 21:20:34 -0500 Message-Id: <20200223022119.707-13-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200223022119.707-1-sashal@kernel.org> References: <20200223022119.707-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Trond Myklebust [ Upstream commit cf5b4059ba7197d6cef9c0e024979d178ed8c8ec ] We want to make sure that we revalidate the dentry if and only if we've done an OPEN by filename. In order to avoid races with remote changes to the directory on the server, we want to save the verifier before calling OPEN. The exception is if the server returned a delegation with our OPEN, as we then know that the filename can't have changed on the server. Signed-off-by: Trond Myklebust Reviewed-by: Benjamin Coddington Tested-by: Benjamin Coddington Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin --- fs/nfs/nfs4file.c | 1 - fs/nfs/nfs4proc.c | 18 ++++++++++++++++-- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c index 620de905cba97..3f892035c1413 100644 --- a/fs/nfs/nfs4file.c +++ b/fs/nfs/nfs4file.c @@ -86,7 +86,6 @@ nfs4_file_open(struct inode *inode, struct file *filp) if (inode != d_inode(dentry)) goto out_drop; - nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); nfs_file_set_open_context(filp, ctx); nfs_fscache_open_file(inode, filp); err = 0; diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 6ddb4f517d373..13c2de527718a 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2962,10 +2962,13 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata, struct dentry *dentry; struct nfs4_state *state; fmode_t acc_mode = _nfs4_ctx_to_accessmode(ctx); + struct inode *dir = d_inode(opendata->dir); + unsigned long dir_verifier; unsigned int seq; int ret; seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); + dir_verifier = nfs_save_change_attribute(dir); ret = _nfs4_proc_open(opendata, ctx); if (ret != 0) @@ -2993,8 +2996,19 @@ static int _nfs4_open_and_get_state(struct nfs4_opendata *opendata, dput(ctx->dentry); ctx->dentry = dentry = alias; } - nfs_set_verifier(dentry, - nfs_save_change_attribute(d_inode(opendata->dir))); + } + + switch(opendata->o_arg.claim) { + default: + break; + case NFS4_OPEN_CLAIM_NULL: + case NFS4_OPEN_CLAIM_DELEGATE_CUR: + case NFS4_OPEN_CLAIM_DELEGATE_PREV: + if (!opendata->rpc_done) + break; + if (opendata->o_res.delegation_type != 0) + dir_verifier = nfs_save_change_attribute(dir); + nfs_set_verifier(dentry, dir_verifier); } /* Parse layoutget results before we check for access */ -- 2.20.1