From: Trond Myklebust Subject: Re: [PATCH] nfs client: kill compile warning on NOMMU machine Date: Thu, 05 Feb 2009 10:37:45 -0500 Message-ID: <1233848265.7161.101.camel@heimdal.trondhjem.org> References: <1225962921-6424-1-git-send-email-cooloney@kernel.org> <386072610902050102r3c3e41a3yfbb424411f2f40dc@mail.gmail.com> <1233840498.7161.97.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org To: Bryan Wu Return-path: Received: from mx2.netapp.com ([216.240.18.37]:41297 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753376AbZBEPiY (ORCPT ); Thu, 5 Feb 2009 10:38:24 -0500 In-Reply-To: <1233840498.7161.97.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 2009-02-05 at 08:28 -0500, Trond Myklebust wrote: > On Thu, 2009-02-05 at 17:02 +0800, Bryan Wu wrote: > > Hi guys, > > > > Is it possible to merge this patch? > > NACK. Although it would be nice to get rid of the warning, this patch > does so at the price of even further obfuscating the fact that we're > just returning -ENOSYS in the no MMU case, and by causing > nfs_file_vm_ops (which is currently optimised away) to be compiled in > for no good reason at all. > > Trond How about the following compromise: we get rid of the special casing altogether and just always call generic_file_mmap. If the noMMU folks want further optimisations, then they can inline generic_file_mmap(), so that the compiler always takes the 'generic_file_mmap() failed' path. Cheers Trond ------------------------------------------------------------ From: Trond Myklebust Date: Thu, 5 Feb 2009 10:23:36 -0500 NFS: Kill the "defined but not used" compile error on nommu machines Bryan Wu reports that when compiling NFS on nommu machines he gets a "defined but not used" error on nfs_file_mmap(). The easiest fix is simply to get rid of the special casing in NFS, and just always call generic_file_mmap() to set up the file. Signed-off-by: Trond Myklebust --- fs/nfs/file.c | 12 +++++------- 1 files changed, 5 insertions(+), 7 deletions(-) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 404c19c..1eab9c9 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -64,11 +64,7 @@ const struct file_operations nfs_file_operations = { .write = do_sync_write, .aio_read = nfs_file_read, .aio_write = nfs_file_write, -#ifdef CONFIG_MMU .mmap = nfs_file_mmap, -#else - .mmap = generic_file_mmap, -#endif .open = nfs_file_open, .flush = nfs_file_flush, .release = nfs_file_release, @@ -304,11 +300,13 @@ nfs_file_mmap(struct file * file, struct vm_area_struct * vma) dprintk("NFS: mmap(%s/%s)\n", dentry->d_parent->d_name.name, dentry->d_name.name); - status = nfs_revalidate_mapping(inode, file->f_mapping); + /* Note: generic_file_mmap() returns ENOSYS on nommu systems + * so we call that before revalidating the mapping + */ + status = generic_file_mmap(file, vma); if (!status) { vma->vm_ops = &nfs_file_vm_ops; - vma->vm_flags |= VM_CAN_NONLINEAR; - file_accessed(file); + status = nfs_revalidate_mapping(inode, file->f_mapping); } return status; } -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@netapp.com www.netapp.com