From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: [PATCH 1/8] xfs: mmap lock needs to be inside freeze protection Date: Tue, 24 Mar 2015 21:50:59 +1100 Message-ID: <1427194266-2885-2-git-send-email-david@fromorbit.com> References: <1427194266-2885-1-git-send-email-david@fromorbit.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, willy@linux.intel.com, jack@suse.cz To: xfs@oss.sgi.com Return-path: In-Reply-To: <1427194266-2885-1-git-send-email-david@fromorbit.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com List-Id: linux-fsdevel.vger.kernel.org From: Dave Chinner Lock ordering for the new mmap lock needs to be: mmap_sem sb_start_pagefault i_mmap_lock page lock Right now xfs_vm_page_mkwrite gets this the wrong way around, While technically it cannot deadlock due to the current freeze ordering, it's still a landmine that might explode if we change anything in future. Hence we need to nest the locks correctly. Signed-off-by: Dave Chinner --- fs/xfs/xfs_file.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index dc5f609..a4c882e 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -1449,15 +1449,20 @@ xfs_filemap_page_mkwrite( struct vm_fault *vmf) { struct xfs_inode *ip = XFS_I(vma->vm_file->f_mapping->host); - int error; + int ret; trace_xfs_filemap_page_mkwrite(ip); + sb_start_pagefault(VFS_I(ip)->i_sb); + file_update_time(vma->vm_file); xfs_ilock(ip, XFS_MMAPLOCK_SHARED); - error = block_page_mkwrite(vma, vmf, xfs_get_blocks); + + ret = __block_page_mkwrite(vma, vmf, xfs_get_blocks); + xfs_iunlock(ip, XFS_MMAPLOCK_SHARED); + sb_end_pagefault(VFS_I(ip)->i_sb); - return error; + return block_page_mkwrite_return(ret); } const struct file_operations xfs_file_operations = { -- 2.0.0 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs