From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail105.syd.optusnet.com.au ([211.29.132.249]:60305 "EHLO mail105.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726053AbfHIXbt (ORCPT ); Fri, 9 Aug 2019 19:31:49 -0400 Date: Sat, 10 Aug 2019 09:30:37 +1000 From: Dave Chinner Subject: Re: [RFC PATCH v2 07/19] fs/xfs: Teach xfs to use new dax_layout_busy_page() Message-ID: <20190809233037.GB7777@dread.disaster.area> References: <20190809225833.6657-1-ira.weiny@intel.com> <20190809225833.6657-8-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190809225833.6657-8-ira.weiny@intel.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: ira.weiny@intel.com Cc: Andrew Morton , Jason Gunthorpe , Dan Williams , Matthew Wilcox , Jan Kara , Theodore Ts'o , John Hubbard , Michal Hocko , linux-xfs@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org On Fri, Aug 09, 2019 at 03:58:21PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > dax_layout_busy_page() can now operate on a sub-range of the > address_space provided. > > Have xfs specify the sub range to dax_layout_busy_page() Hmmm. I've got patches that change all these XFS interfaces to support range locks. I'm not sure the way the ranges are passed here is the best way to do it, and I suspect they aren't correct in some cases, either.... > diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c > index ff3c1fae5357..f0de5486f6c1 100644 > --- a/fs/xfs/xfs_iops.c > +++ b/fs/xfs/xfs_iops.c > @@ -1042,10 +1042,16 @@ xfs_vn_setattr( > xfs_ilock(ip, XFS_MMAPLOCK_EXCL); > iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL; > > - error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP); > - if (error) { > - xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); > - return error; > + if (iattr->ia_size < inode->i_size) { > + loff_t off = iattr->ia_size; > + loff_t len = inode->i_size - iattr->ia_size; > + > + error = xfs_break_layouts(inode, &iolock, off, len, > + BREAK_UNMAP); > + if (error) { > + xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); > + return error; > + } This isn't right - truncate up still needs to break the layout on the last filesystem block of the file, and truncate down needs to extend to "maximum file offset" because we remove all extents beyond EOF on a truncate down. i.e. when we use preallocation, the extent map extends beyond EOF, and layout leases need to be able to extend beyond the current EOF to allow the lease owner to do extending writes, extending truncate, preallocation beyond EOF, etc safely without having to get a new lease to cover the new region in the extended file... Cheers, Dave. -- Dave Chinner david@fromorbit.com