Mountable btrfs, with readdir

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --cc fs/btrfs/Makefile
Simple merge

diff --cc fs/btrfs/ctree.c
Simple merge

diff --cc fs/btrfs/ctree.h
Simple merge

diff --cc fs/btrfs/dir-item.c
Simple merge

diff --cc fs/btrfs/disk-io.c
Simple merge

diff --cc fs/btrfs/disk-io.h
Simple merge

diff --cc fs/btrfs/extent-tree.c
Simple merge

diff --cc fs/btrfs/hash.c
Simple merge

diff --cc fs/btrfs/inode-map.c
Simple merge

diff --cc fs/btrfs/print-tree.c
Simple merge

diff --cc fs/btrfs/print-tree.h
Simple merge

diff --cc fs/btrfs/root-tree.c
Simple merge

diff --cc fs/btrfs/super.c
Simple merge

diff --cc fs/btrfs/transaction.h
Simple merge