From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 12 Oct 2018 12:15:53 +1100 From: Dave Chinner To: "Darrick J. Wong" Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com Subject: Re: [PATCH 23/25] xfs: fix pagecache truncation prior to reflink Message-ID: <20181012011553.GS6311@dastard> References: <153923113649.5546.9840926895953408273.stgit@magnolia> <153923131273.5546.6811645962559576222.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153923131273.5546.6811645962559576222.stgit@magnolia> Sender: owner-linux-mm@kvack.org List-ID: On Wed, Oct 10, 2018 at 09:15:12PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > Prior to remapping blocks, it is necessary to remove pages from the > destination file's page cache. Unfortunately, the truncation is not > aggressive enough -- if page size > block size, we'll end up zeroing > subpage blocks instead of removing them. So, round the start offset > down and the end offset up to page boundaries. We already wrote all > the dirty data so the larger range shouldn't be a problem. > > Signed-off-by: Darrick J. Wong > --- > fs/xfs/xfs_reflink.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index b24a2a1c4db1..e1592e751cc2 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -1370,8 +1370,9 @@ xfs_reflink_remap_prep( > goto out_unlock; > > /* Zap any page cache for the destination file's range. */ > - truncate_inode_pages_range(&inode_out->i_data, pos_out, > - PAGE_ALIGN(pos_out + *len) - 1); > + truncate_inode_pages_range(&inode_out->i_data, > + round_down(pos_out, PAGE_SIZE), > + round_up(pos_out + *len, PAGE_SIZE) - 1); Looks good. Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com