From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1768054AbcHROiu (ORCPT ); Thu, 18 Aug 2016 10:38:50 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36978 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1767006AbcHROMe (ORCPT ); Thu, 18 Aug 2016 10:12:34 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Benjamin Coddington , Alexey Dobriyan , Weston Andros Adamson , Trond Myklebust Subject: [PATCH 4.7 091/186] nfs: dont create zero-length requests Date: Thu, 18 Aug 2016 15:58:28 +0200 Message-Id: <20160818135936.030503637@linuxfoundation.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20160818135932.219369981@linuxfoundation.org> References: <20160818135932.219369981@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Coddington commit 149a4fddd0a72d526abbeac0c8deaab03559836a upstream. NFS doesn't expect requests with wb_bytes set to zero and may make unexpected decisions about how to handle that request at the page IO layer. Skip request creation if we won't have any wb_bytes in the request. Signed-off-by: Benjamin Coddington Signed-off-by: Alexey Dobriyan Reviewed-by: Weston Andros Adamson Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/write.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1289,6 +1289,9 @@ int nfs_updatepage(struct file *file, st dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n", file, count, (long long)(page_file_offset(page) + offset)); + if (!count) + goto out; + if (nfs_can_extend_write(file, page, inode)) { count = max(count + offset, nfs_page_length(page)); offset = 0; @@ -1299,7 +1302,7 @@ int nfs_updatepage(struct file *file, st nfs_set_pageerror(page); else __set_page_dirty_nobuffers(page); - +out: dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", status, (long long)i_size_read(inode)); return status;