Orabug: 18108070

ocfs2_xattr_extend_allocation() hits panic when creating xattr during
data extent alloc phase.  The problem occurs if due to local alloc
fragmentation, clusters are spread over multiple extents.  In this case
ocfs2_add_clusters_in_btree() finds no space to store more than one
extent record and therefore fails returning RESTART_META.  The situation
is anticipated for xattr update case but not xattr create case.  This
fix simply ports that code to create case.
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>