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=-19.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 60A8DC433E0 for ; Mon, 8 Feb 2021 15:57:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D22564E85 for ; Mon, 8 Feb 2021 15:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234202AbhBHP5m (ORCPT ); Mon, 8 Feb 2021 10:57:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:52608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231703AbhBHPIX (ORCPT ); Mon, 8 Feb 2021 10:08:23 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id AE75E64E37; Mon, 8 Feb 2021 15:06:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612796778; bh=y3HFXHh4J87OKwkm0AAzriIiV39AZD39ydaNve9IVVE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cOTWX8+Z6QiMqvvn8rV9XD14DVqen97Ndu3SqZUsrDdVtDFmk1+3NQEDH9Qxi+T0m h/ufM6JWyFZu2DL7spvJsS2YDOjM9H6d2io3MvQrHtYcqxJEhSoX+9H2qm4KEeTCWa SXkoppt0HgvsmKiZwsJKq6oVgUV1bkUZs/fywKRo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Aurelien Aptel , Shyam Prasad N , Steve French Subject: [PATCH 4.14 17/30] cifs: report error instead of invalid when revalidating a dentry fails Date: Mon, 8 Feb 2021 16:01:03 +0100 Message-Id: <20210208145805.943909807@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210208145805.239714726@linuxfoundation.org> References: <20210208145805.239714726@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Aurelien Aptel commit 21b200d091826a83aafc95d847139b2b0582f6d1 upstream. Assuming - //HOST/a is mounted on /mnt - //HOST/b is mounted on /mnt/b On a slow connection, running 'df' and killing it while it's processing /mnt/b can make cifs_get_inode_info() returns -ERESTARTSYS. This triggers the following chain of events: => the dentry revalidation fail => dentry is put and released => superblock associated with the dentry is put => /mnt/b is unmounted This patch makes cifs_d_revalidate() return the error instead of 0 (invalid) when cifs_revalidate_dentry() fails, except for ENOENT (file deleted) and ESTALE (file recreated). Signed-off-by: Aurelien Aptel Suggested-by: Shyam Prasad N Reviewed-by: Shyam Prasad N CC: stable@vger.kernel.org Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/dir.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -841,6 +841,7 @@ static int cifs_d_revalidate(struct dentry *direntry, unsigned int flags) { struct inode *inode; + int rc; if (flags & LOOKUP_RCU) return -ECHILD; @@ -850,8 +851,25 @@ cifs_d_revalidate(struct dentry *direntr if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode))) CIFS_I(inode)->time = 0; /* force reval */ - if (cifs_revalidate_dentry(direntry)) - return 0; + rc = cifs_revalidate_dentry(direntry); + if (rc) { + cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc); + switch (rc) { + case -ENOENT: + case -ESTALE: + /* + * Those errors mean the dentry is invalid + * (file was deleted or recreated) + */ + return 0; + default: + /* + * Otherwise some unexpected error happened + * report it as-is to VFS layer + */ + return rc; + } + } else { /* * If the inode wasn't known to be a dfs entry when