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 68E13C433E0 for ; Mon, 8 Feb 2021 15:18:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2960B60238 for ; Mon, 8 Feb 2021 15:18:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230410AbhBHPSS (ORCPT ); Mon, 8 Feb 2021 10:18:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:52064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232859AbhBHPD5 (ORCPT ); Mon, 8 Feb 2021 10:03:57 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A8A5C64E8A; Mon, 8 Feb 2021 15:02:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612796572; bh=vI7ctVkbdPVnwQH6bjkIpC1+6VwQIp0RYP3vi4fcqRw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wboeOgQZtChrE4IYXCS97c4zzoqciVTxRtNuBCyjDb2BZEWX4vO6E0xbA2BDr+A5Y mqtXSYkT5fGca++EBxFUf78qA0sQN2sd7yXEW84EoEhlRIkTP+OkHrNGN6mNr3ztss hMGaVamTnWJ9OCSDCjpElYkYUk4bwt9wTFvzg0dM= 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 4.4 28/38] cifs: report error instead of invalid when revalidating a dentry fails Date: Mon, 8 Feb 2021 16:00:50 +0100 Message-Id: <20210208145806.384124458@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210208145805.279815326@linuxfoundation.org> References: <20210208145805.279815326@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 @@ -831,6 +831,7 @@ static int cifs_d_revalidate(struct dentry *direntry, unsigned int flags) { struct inode *inode; + int rc; if (flags & LOOKUP_RCU) return -ECHILD; @@ -840,8 +841,25 @@ 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