Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

Merge git://git./linux/kernel/git/mason/btrfs-unstable

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: check return value of alloc_extent_map()
  Btrfs - Fix memory leak in btrfs_init_new_device()
  btrfs: prevent heap corruption in btrfs_ioctl_space_info()
  Btrfs: Fix balance panic
  Btrfs: don't release pages when we can't clear the uptodate bits
  Btrfs: fix page->private races