* Make sure nobh stuff is working properly for cows
* Do actual block accounting
* Check compat and incompat flags on the inode
-* Add virtual filesystems, mountable snapshots
* Get rid of struct ctree_path, limiting tree levels held at one time
-* EEXIST for dirs instead of hash overflow
* Release
* Do real tree locking
* Add extent mirroring (backup copies of blocks)
* fsck
* Scrub & defrag
----
-metata FS ideas:
-mount metadata FS on /sys/fs/btrfs/dev/
-subvolumes in /sys/fs/btrfs/dev/fs/
-snapshots in /sys/fs/btrfs/dev/fs/snapshots
-mount -o bind
-ioctl to create a snapshot
#define BTRFS_ROOT_TREE_OBJECTID 1ULL
#define BTRFS_EXTENT_TREE_OBJECTID 2ULL
#define BTRFS_FS_TREE_OBJECTID 3ULL
-#define BTRFS_FIRST_FREE_OBJECTID 4ULL
+#define BTRFS_ROOT_TREE_DIR_OBJECTID 4ULL
+#define BTRFS_FIRST_FREE_OBJECTID 5ULL
/*
* we can actually store much bigger names, but lets not confuse the rest