On May 5, 2013, at 10:06 PM, "Theodore Ts'o" [off-list ref] wrote:

On Fri, May 03, 2013 at 04:06:56PM -0500, Eric Sandeen wrote:

quoted

s_blockfile_groups is used to limit allocations for non-extent
files to block groups with block numbers less than 2^32.
However, it's not updated when the filesystem is resized online,
so the new groups are unavailable to non-extent files until a remount.

Fix this by updating the value in ext4_update_super() at
resize time.

Signed-off-by: Eric Sandeen <redacted>

I sent out a patch about two weeks ago, which has since been accepted
into Linus's tree as commit c5c72d814cf0.  It's been marked for the
for backporting into the stable trees.

Argh, so you did!  One demerit for me for forgetting, and another for patching an old tree....

Thanks,
Eric

Cheers,

                       - Ted

commit c5c72d814cf0f650010337c73638b25e6d14d2d4
Author: Theodore Ts'o [off-list ref]
Date:   Sun Apr 21 20:19:43 2013 -0400

   ext4: fix online resizing for ext3-compat file systems

   Commit fb0a387dcdc restricts block allocations for indirect-mapped
   files to block groups less than s_blockfile_groups.  However, the
   online resizing code wasn't setting s_blockfile_groups, so the newly
   added block groups were not available for non-extent mapped files.

   Reported-by: Eric Sandeen [off-list ref]
   Signed-off-by: "Theodore Ts'o" [off-list ref]
   Cc: stable@vger.kernel.org