From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from verein.lst.de (verein.lst.de [213.95.11.210]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 02E9CDDF38 for ; Thu, 13 Mar 2008 21:13:20 +1100 (EST) Date: Thu, 13 Mar 2008 11:12:48 +0100 From: Christoph Hellwig To: "Theodore Ts'o" Subject: Re: [PATCH] ppc: Export empty_zero_page Message-ID: <20080313101248.GA4297@lst.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Mar 11, 2008 at 10:44:06PM -0400, Theodore Ts'o wrote: > Stephen Rothwell discovered this issue in the linux-next tree: > > >Today's powerpc allmodconfig build of linux-next failed with: > > > >ERROR: "empty_zero_page" [fs/ext4/ext4dev.ko] undefined! > > > >This is because commit dde5f2130096f8469eb1aa1ad250cd2a39fee3f5 ("ext4: > >ENOSPC error handling for writing to an uninitialized extent") uses > >ZERO_PAGE() which on powerpc uses empty_zero_page which is not > >EXPORT_SYMBOLed on powerpc. I have reverted that commit and a later > >one (1ae53f35fea49a9013353078e019469551d2ad74 "ext4: zero out > >small extents when writing to prealloc area.") which depended on it. > > Any chance you could get this pushed to Linus ASAP? It would be nice if > this could get pushed before the merge window, since it could be argued > that rationalizing whether or not empty_zero_page is exported is a bug > fix, and anyway this is pretty much a zero-risk patch. Thanks!! The real fix is that ext4 shouldn't be using ZERO_PAGE(). Please use the same zeroing helpers all the other filesystems and drivers use.