From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Sun, 07 Jan 2007 20:04:16 -0800 (PST) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with SMTP id l08447qw032484 for ; Sun, 7 Jan 2007 20:04:09 -0800 Date: Mon, 8 Jan 2007 15:03:09 +1100 From: David Chinner Subject: Review: fix mapping invalidation callouts Message-ID: <20070108040309.GX33919298@melbourne.sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: xfs-dev@sgi.com Cc: xfs@oss.sgi.com With the recent cancel_dirty_page() changes, a warning was added if we cancel a dirty page that is still mapped into the page tables. This happens in XFS from fs_tosspages() and fs_flushinval_pages() because they call truncate_inode_pages(). truncate_inode_pages() does not invalidate existing page mappings; it is expected taht this is called only when truncating the file or destroying the inode and on both these cases there can be no mapped ptes. However, we call this when doing direct I/O writes to remove pages from the page cache. As a result, we can rip a page from the page cache that still has mappings attached. The correct fix is to use invalidate_inode_pages2_range() instead of truncate_inode_pages(). They essentially do the same thing, but the former also removes any pte mappings before removing the page from the page cache. Comments? Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group --- fs/xfs/linux-2.6/xfs_fs_subr.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) Index: 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_fs_subr.c =================================================================== --- 2.6.x-xfs-new.orig/fs/xfs/linux-2.6/xfs_fs_subr.c 2006-12-12 12:05:17.000000000 +1100 +++ 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_fs_subr.c 2007-01-08 09:30:22.056571711 +1100 @@ -21,6 +21,8 @@ int fs_noerr(void) { return 0; } int fs_nosys(void) { return ENOSYS; } void fs_noval(void) { return; } +#define XFS_OFF_TO_PCSIZE(off) \ + (((off) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT) void fs_tosspages( bhv_desc_t *bdp, @@ -32,7 +34,9 @@ fs_tosspages( struct inode *ip = vn_to_inode(vp); if (VN_CACHED(vp)) - truncate_inode_pages(ip->i_mapping, first); + invalidate_inode_pages2_range(ip->i_mapping, + XFS_OFF_TO_PCSIZE(first), + XFS_OFF_TO_PCSIZE(last)); } void @@ -49,7 +53,9 @@ fs_flushinval_pages( if (VN_TRUNC(vp)) VUNTRUNCATE(vp); filemap_write_and_wait(ip->i_mapping); - truncate_inode_pages(ip->i_mapping, first); + invalidate_inode_pages2_range(ip->i_mapping, + XFS_OFF_TO_PCSIZE(first), + XFS_OFF_TO_PCSIZE(last)); } }