gfs2: gfs2_walk_metadata fix
It turns out that the current version of gfs2_metadata_walker suffers
from multiple problems that can cause gfs2_hole_size to report an
incorrect size. This will confuse fiemap as well as lseek with the
SEEK_DATA flag.
Fix that by changing gfs2_hole_walker to compute the metapath to the
first data block after the hole (if any), and compute the hole size
based on that.
Fixes xfstest generic/490.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Cc: stable@vger.kernel.org # v4.18+