From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423672AbcFMSxR (ORCPT ); Mon, 13 Jun 2016 14:53:17 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43698 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161340AbcFMShb (ORCPT ); Mon, 13 Jun 2016 14:37:31 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Dave Chinner" , xfs@oss.sgi.com, "Jan Kara" , "Brian Foster" , "Dave Chinner" Date: Mon, 13 Jun 2016 19:36:37 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 093/114] xfs: use i_mmaplock on write faults In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.36-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dave Chinner commit 075a924d45cc69c75a35f20b4912b85aa98b180a upstream. Take the i_mmaplock over write page faults. These come through the ->page_mkwrite callout, so we need to wrap that calls with the i_mmaplock. This gives us a lock order of mmap_sem -> i_mmaplock -> page_lock -> i_lock. Also, move the page_mkwrite wrapper to the same region of xfs_file.c as the read fault wrappers and add a tracepoint. Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Signed-off-by: Dave Chinner [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings Cc: Jan Kara Cc: xfs@oss.sgi.com --- fs/xfs/xfs_file.c | 39 ++++++++++++++++++++++++--------------- fs/xfs/xfs_trace.h | 1 + 2 files changed, 25 insertions(+), 15 deletions(-) --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -957,20 +957,6 @@ xfs_file_mmap( } /* - * mmap()d file has taken write protection fault and is being made - * writable. We can set the page state up correctly for a writable - * page, which means we can do correct delalloc accounting (ENOSPC - * checking!) and unwritten extent mapping. - */ -STATIC int -xfs_vm_page_mkwrite( - struct vm_area_struct *vma, - struct vm_fault *vmf) -{ - return block_page_mkwrite(vma, vmf, xfs_get_blocks); -} - -/* * This type is designed to indicate the type of offset we would like * to search from page cache for either xfs_seek_data() or xfs_seek_hole(). */ @@ -1443,6 +1429,29 @@ xfs_filemap_fault( return error; } +/* + * mmap()d file has taken write protection fault and is being made writable. We + * can set the page state up correctly for a writable page, which means we can + * do correct delalloc accounting (ENOSPC checking!) and unwritten extent + * mapping. + */ +STATIC int +xfs_filemap_page_mkwrite( + struct vm_area_struct *vma, + struct vm_fault *vmf) +{ + struct xfs_inode *ip = XFS_I(vma->vm_file->f_mapping->host); + int error; + + trace_xfs_filemap_page_mkwrite(ip); + + xfs_ilock(ip, XFS_MMAPLOCK_SHARED); + error = block_page_mkwrite(vma, vmf, xfs_get_blocks); + xfs_iunlock(ip, XFS_MMAPLOCK_SHARED); + + return error; +} + const struct file_operations xfs_file_operations = { .llseek = xfs_file_llseek, .read = new_sync_read, @@ -1477,6 +1486,6 @@ const struct file_operations xfs_dir_fil static const struct vm_operations_struct xfs_file_vm_ops = { .fault = xfs_filemap_fault, .map_pages = filemap_map_pages, - .page_mkwrite = xfs_vm_page_mkwrite, + .page_mkwrite = xfs_filemap_page_mkwrite, .remap_pages = generic_file_remap_pages, }; --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -685,6 +685,7 @@ DEFINE_INODE_EVENT(xfs_inode_clear_eofbl DEFINE_INODE_EVENT(xfs_inode_free_eofblocks_invalid); DEFINE_INODE_EVENT(xfs_filemap_fault); +DEFINE_INODE_EVENT(xfs_filemap_page_mkwrite); DECLARE_EVENT_CLASS(xfs_iref_class, TP_PROTO(struct xfs_inode *ip, unsigned long caller_ip),