I've been watching how many btrfs_search_slot()'s we do and I noticed that when
we create a file with selinux enabled we were doing 2 each time we initialize
the security context. That's because we lookup the xattr first so we can delete
it if we're setting a new value to an existing xattr. But in the create case we
don't have any xattrs, so it is completely useless to have the extra lookup. So
re-arrange things so that we only lookup first if we specifically have
XATTR_REPLACE. That way in the basic case we only do 1 search, and in the more
complicated case we do the normal 2 lookups. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
fa09200b83