Pull btrfs fixes from Chris Mason:
 "Miao Xie has been very busy, fixing races and enospc problems and many
  other small but important pieces.

  Alexandre Oliva discovered some problems with how our error handling
  was interacting with the block layer and for now has disabled our
  partial handling of sub-page writes.  The real sub-page work is in a
  series of patches from IBM that we still need to integrate and test.
  The code Alexandre has turned off was really incomplete.

  Josef has more error handling fixes and an important fix for the new
  skinny extent format.

  This also has my fix for the tracepoint crash from late in 3.9.  It's
  the first stage in a larger clean up to get rid of btrfs_bio and make
  a proper bioset for all the items we need to tack into the bio.  For
  now the bioset only holds our mirror_num and stripe_index, but for the
  next merge window I'll shuffle more in."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (25 commits)
  Btrfs: use a btrfs bioset instead of abusing bio internals
  Btrfs: make sure roots are assigned before freeing their nodes
  Btrfs: explicitly use global_block_rsv for quota_tree
  btrfs: do away with non-whole_page extent I/O
  Btrfs: don't invoke btrfs_invalidate_inodes() in the spin lock context
  Btrfs: remove BUG_ON() in btrfs_read_fs_tree_no_radix()
  Btrfs: pause the space balance when remounting to R/O
  Btrfs: fix unprotected root node of the subvolume's inode rb-tree
  Btrfs: fix accessing a freed tree root
  Btrfs: return errno if possible when we fail to allocate memory
  Btrfs: update the global reserve if it is empty
  Btrfs: don't steal the reserved space from the global reserve if their space type is different
  Btrfs: optimize the error handle of use_block_rsv()
  Btrfs: don't use global block reservation for inode cache truncation
  Btrfs: don't abort the current transaction if there is no enough space for inode cache
  Correct allowed raid levels on balance.
  Btrfs: fix possible memory leak in replace_path()
  Btrfs: fix possible memory leak in the find_parent_nodes()
  Btrfs: don't allow device replace on RAID5/RAID6
  Btrfs: handle running extent ops with skinny metadata
  ...