Pull btrfs updates from David Sterba:
 "This time the majority of changes are cleanups, though there's still a
  number of changes of user interest.

  User visible changes:

   - better read time and write checks to catch errors early and before
     writing data to disk (to catch potential memory corruption on data
     that get checksummed)

   - qgroups + metadata relocation: last speed up patch int the series
     to address the slowness, there should be no overhead comparing
     balance with and without qgroups

   - FIEMAP ioctl does not start a transaction unnecessarily, this can
     result in a speed up and less blocking due to IO

   - LOGICAL_INO (v1, v2) does not start transaction unnecessarily, this
     can speed up the mentioned ioctl and scrub as well

   - fsync on files with many (but not too many) hardlinks is faster,
     finer decision if the links should be fsynced individually or
     completely

   - send tries harder to find ranges to clone

   - trim/discard will skip unallocated chunks that haven't been touched
     since the last mount

  Fixes:

   - send flushes delayed allocation before start, otherwise it could
     miss some changes in case of a very recent rw->ro switch of a
     subvolume

   - fix fallocate with qgroups that could lead to space accounting
     underflow, reported as a warning

   - trim/discard ioctl honours the requested range

   - starting send and dedupe on a subvolume at the same time will let
     only one of them succeed, this is to prevent changes that send
     could miss due to dedupe; both operations are restartable

  Core changes:

   - more tree-checker validations, errors reported by fuzzing tools:
      - device item
      - inode item
      - block group profiles

   - tracepoints for extent buffer locking

   - async cow preallocates memory to avoid errors happening too deep in
     the call chain

   - metadata reservations for delalloc reworked to better adapt in
     many-writers/low-space scenarios

   - improved space flushing logic for intense DIO vs buffered workloads

   - lots of cleanups
      - removed unused struct members
      - redundant argument removal
      - properties and xattrs
      - extent buffer locking
      - selftests
      - use common file type conversions
      - many-argument functions reduction"

* tag 'for-5.2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (227 commits)
  btrfs: Use kvmalloc for allocating compressed path context
  btrfs: Factor out common extent locking code in submit_compressed_extents
  btrfs: Set io_tree only once in submit_compressed_extents
  btrfs: Replace clear_extent_bit with unlock_extent
  btrfs: Make compress_file_range take only struct async_chunk
  btrfs: Remove fs_info from struct async_chunk
  btrfs: Rename async_cow to async_chunk
  btrfs: Preallocate chunks in cow_file_range_async
  btrfs: reserve delalloc metadata differently
  btrfs: track DIO bytes in flight
  btrfs: merge calls of btrfs_setxattr and btrfs_setxattr_trans in btrfs_set_prop
  btrfs: delete unused function btrfs_set_prop_trans
  btrfs: start transaction in xattr_handler_set_prop
  btrfs: drop local copy of inode i_mode
  btrfs: drop old_fsflags in btrfs_ioctl_setflags
  btrfs: modify local copy of btrfs_inode flags
  btrfs: drop useless inode i_flags copy and restore
  btrfs: start transaction in btrfs_ioctl_setflags()
  btrfs: export btrfs_set_prop
  btrfs: refactor btrfs_set_props to validate externally
  ...