From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755774Ab0BSRNN (ORCPT ); Fri, 19 Feb 2010 12:13:13 -0500 Received: from kroah.org ([198.145.64.141]:57514 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754544Ab0BSRAd (ORCPT ); Fri, 19 Feb 2010 12:00:33 -0500 X-Mailbox-Line: From gregkh@kvm.kroah.org Fri Feb 19 08:32:40 2010 Message-Id: <20100219163240.351599545@kvm.kroah.org> User-Agent: quilt/0.48-4.4 Date: Fri, 19 Feb 2010 08:29:28 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Trond Myklebust Subject: [35/93] NFS: Fix an Oops when truncating a file In-Reply-To: <20100219165717.GA15002@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: Trond Myklebust commit 9f557cd8073104b39528794d44e129331ded649f upstream. The VM/VFS does not allow mapping->a_ops->invalidatepage() to fail. Unfortunately, nfs_wb_page_cancel() may fail if a fatal signal occurs. Since the NFS code assumes that the page stays mapped for as long as the writeback is active, we can end up Oopsing (among other things). The only safe fix here is to convert nfs_wait_on_request(), so as to make it uninterruptible (as is already the case with wait_on_page_writeback()). Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -176,6 +176,12 @@ void nfs_release_request(struct nfs_page *req) kref_put(&req->wb_kref, nfs_free_request); } +static int nfs_wait_bit_uninterruptible(void *word) +{ + io_schedule(); + return 0; +} + /** * nfs_wait_on_request - Wait for a request to complete. * @req: request to wait upon. @@ -186,14 +192,9 @@ void nfs_release_request(struct nfs_page *req) int nfs_wait_on_request(struct nfs_page *req) { - int ret = 0; - - if (!test_bit(PG_BUSY, &req->wb_flags)) - goto out; - ret = out_of_line_wait_on_bit(&req->wb_flags, PG_BUSY, - nfs_wait_bit_killable, TASK_KILLABLE); -out: - return ret; + return wait_on_bit(&req->wb_flags, PG_BUSY, + nfs_wait_bit_uninterruptible, + TASK_UNINTERRUPTIBLE); } /**