The implementation of ulist_* is same for kernel and userspace, without
dependencies, so we can keep it separately for code sync.
Signed-off-by: David Sterba <dsterba@suse.com>
This patch pulls back backref.c, adds a couple of helpers everywhere that it
needs, and cleans up backref.c to fit in btrfs-progs. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
[removed free_some_buffers after "do not reclaim extent buffer"]
Signed-off-by: David Sterba <dsterba@suse.cz>