On Mon, Jan 13, 2020 at 02:27:55PM -0800, Darrick J. Wong wrote:

On Fri, Jan 10, 2020 at 11:29:40AM -0800, ira.weiny@intel.com wrote:

quoted

From: Ira Weiny <redacted>

When zeroing the end of a file we must account for bytes contained in
the final page which are past EOF.

Extend the range passed to iomap_zero_range() to reach LLONG_MAX which
will include all bytes of the final page.

Signed-off-by: Ira Weiny <redacted>
---
 fs/xfs/xfs_iops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index a2f2604c3187..a34b04e8ac9c 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c

@@ -910,7 +910,7 @@ xfs_setattr_size(
 	 */
 	if (newsize > oldsize) {
 		trace_xfs_zero_eof(ip, oldsize, newsize - oldsize);
-		error = iomap_zero_range(inode, oldsize, newsize - oldsize,
+		error = iomap_zero_range(inode, oldsize, LLONG_MAX - oldsize,

Huh?  Won't this cause the file size to be set to LLONG_MAX?

Not as I understand the code.  But as I said in the cover I am not 100% sure of
this fix.

From what I can tell xfs_ioctl_setattr_dax_invalidate() should invalidate the
mappings and the page cache and the traces I have indicate that the DAX mode
is not changing or was properly held off.

Any other suggestions as to the problem are welcome.

Ira

--D

quoted

 				&did_zeroing, &xfs_buffered_write_iomap_ops);
 	} else {
 		error = iomap_truncate_page(inode, newsize, &did_zeroing,
-- 
2.21.0