• Zheng Yan's avatar
    Btrfs: Add shared reference cache · e4657689
    Zheng Yan authored
    
    
    Btrfs has a cache of reference counts in leaves, allowing it to
    avoid reading tree leaves while deleting snapshots.  To reduce
    contention with multiple subvolumes, this cache is private to each
    subvolume.
    
    This patch adds shared reference cache support. The new space
    balancing code plays with multiple subvols at the same time, So
    the old per-subvol reference cache is not well suited.
    Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
    e4657689