Re: BUG: warning at mm/truncate.c:60/cancel_dirty_page()

David Chinner
2007-01-07T23:05:54Z

On Sun, Jan 07, 2007 at 02:48:12PM -0800, Andrew Morton wrote:
> On Mon, 8 Jan 2007 09:23:41 +1100
> David Chinner <dgc@sgi.com> wrote:
>
> > How are you supposed to invalidate a range of pages in a mapping for
> > this case, then? invalidate_mapping_pages() would appear to be the
> > candidate (the generic code uses this), but it _skips_ pages that
> > are already mapped.
>
> unmap_mapping_range()?

/me looks at how it's used in invalidate_inode_pages2_range() and
decides it's easier not to call this directly.

> > So, am I correct in assuming we should be calling invalidate_inode_pages2_range()
> > instead of truncate_inode_pages()?
>
> That would be conventional.

.... in that case the following patch should fix the warning:

---
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));
}
}

--
Dave Chinner
Principal Engineer
SGI Australian Software Group