Pull btrfs updates from Chris Mason:
 "This pull is dedicated to Josef's enospc rework, which we've been
  testing for a few releases now.  It fixes some early enospc problems
  and is dramatically faster.

  This also includes an updated fix for the delalloc accounting that
  happens after a fault in copy_from_user.  My patch in v4.7 was almost
  but not quite enough"

* 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix delalloc accounting after copy_from_user faults
  Btrfs: avoid deadlocks during reservations in btrfs_truncate_block
  Btrfs: use FLUSH_LIMIT for relocation in reserve_metadata_bytes
  Btrfs: fill relocation block rsv after allocation
  Btrfs: always use trans->block_rsv for orphans
  Btrfs: change how we calculate the global block rsv
  Btrfs: use root when checking need_async_flush
  Btrfs: don't bother kicking async if there's nothing to reclaim
  Btrfs: fix release reserved extents trace points
  Btrfs: add fsid to some tracepoints
  Btrfs: add tracepoints for flush events
  Btrfs: fix delalloc reservation amount tracepoint
  Btrfs: trace pinned extents
  Btrfs: introduce ticketed enospc infrastructure
  Btrfs: add tracepoint for adding block groups
  Btrfs: warn_on for unaccounted spaces
  Btrfs: change delayed reservation fallback behavior
  Btrfs: always reserve metadata for delalloc extents
  Btrfs: fix callers of btrfs_block_rsv_migrate
  Btrfs: add bytes_readonly to the spaceinfo at once