From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: [RFC PATCH 3/6] xfs: use i_mmaplock on write faults Date: Thu, 8 Jan 2015 09:25:40 +1100 Message-ID: <1420669543-8093-4-git-send-email-david@fromorbit.com> References: <1420669543-8093-1-git-send-email-david@fromorbit.com> Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org To: xfs@oss.sgi.com Return-path: Received: from ipmail06.adl2.internode.on.net ([150.101.137.129]:29920 "EHLO ipmail06.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755342AbbAGW0L (ORCPT ); Wed, 7 Jan 2015 17:26:11 -0500 In-Reply-To: <1420669543-8093-1-git-send-email-david@fromorbit.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Dave Chinner 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 --- fs/xfs/xfs_file.c | 39 ++++++++++++++++++++++++--------------- fs/xfs/xfs_trace.h | 1 + 2 files changed, 25 insertions(+), 15 deletions(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 87535e6..e6e7e75 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -961,20 +961,6 @@ 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 xfs_seek_hole_data(). */ @@ -1375,6 +1361,29 @@ 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, @@ -1409,6 +1418,6 @@ const struct file_operations xfs_dir_file_operations = { 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, }; diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index c496153..b1e059b 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -686,6 +686,7 @@ DEFINE_INODE_EVENT(xfs_inode_clear_eofblocks_tag); 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), -- 2.0.0