From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 42F6A7F37 for ; Sun, 18 Oct 2015 22:27:40 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay3.corp.sgi.com (Postfix) with ESMTP id 9C3C0AC001 for ; Sun, 18 Oct 2015 20:27:39 -0700 (PDT) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id YGpMpUX7zsTJBp27 for ; Sun, 18 Oct 2015 20:27:37 -0700 (PDT) From: Dave Chinner Subject: [PATCH 6/6] xfs: xfs_filemap_pmd_fault treats read faults as write faults Date: Mon, 19 Oct 2015 14:27:18 +1100 Message-Id: <1445225238-30413-7-git-send-email-david@fromorbit.com> In-Reply-To: <1445225238-30413-1-git-send-email-david@fromorbit.com> References: <1445225238-30413-1-git-send-email-david@fromorbit.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Cc: ross.zwisler@linux.intel.com, jack@suse.cz From: Dave Chinner The code initially committed didn't have the same checks for write faults as the dax_pmd_fault code and hence treats all faults as write faults. We can get read faults through this path because they is no pmd_mkwrite path for write faults similar to the normal page fault path. Hence we need to ensure that we only do c/mtime updates on write faults, and freeze protection is unnecessary for read faults. Signed-off-by: Dave Chinner --- fs/xfs/xfs_file.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index e7cf9ec..0045b0a 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1482,7 +1482,7 @@ xfs_file_llseek( * * mmap_sem (MM) * sb_start_pagefault(vfs, freeze) - * i_mmap_lock (XFS - truncate serialisation) + * i_mmaplock (XFS - truncate serialisation) * page_lock (MM) * i_lock (XFS - extent map serialisation) */ @@ -1550,6 +1550,13 @@ xfs_filemap_fault( return ret; } +/* + * Similar to xfs_filemap_fault(), the DAX fault path can call into here on + * both read and write faults. Hence we need to handle both cases. There is no + * ->pmd_mkwrite callout for huge pages, so we have a single function here to + * handle both cases here. @flags carries the information on the type of fault + * occuring. + */ STATIC int xfs_filemap_pmd_fault( struct vm_area_struct *vma, @@ -1566,13 +1573,18 @@ xfs_filemap_pmd_fault( trace_xfs_filemap_pmd_fault(ip); - sb_start_pagefault(inode->i_sb); - file_update_time(vma->vm_file); + if (flags & FAULT_FLAG_WRITE) { + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + } + xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED); ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault, NULL); xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED); - sb_end_pagefault(inode->i_sb); + + if (flags & FAULT_FLAG_WRITE) + sb_end_pagefault(inode->i_sb); return ret; } -- 2.5.0 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs