Misc cleanups

Hi,

here's a bunch of cleanups and potential speed improvements when copying extent buffer pages, there are some special cases. I haven't done any performance measurements though.

Patchset target is 4.10, can be found in branch misc-cleanups-4.10 in my repos.

----------------------------------------------------------------
David Sterba (12):
btrfs: reada, cleanup remove unneeded variable in __readahead_hook
btrfs: reada, remove unused parameter from __readahead_hook
btrfs: reada, sink start parameter to btree_readahead_hook
btrfs: reada, remove pointless BUG_ON in reada_find_extent
btrfs: reada, remove pointless BUG_ON check for fs_info
btrfs: remove trivial helper btrfs_find_tree_block
btrfs: delete unused member from superblock
btrfs: introduce helpers for updating eb uuids
btrfs: use new helpers to set uuids in eb
btrfs: use specialized page copying helpers in btrfs_clone_extent_buffer
btrfs: remove constant parameter to memset_extent_buffer and rename it
btrfs: add optimized version of eb to eb copy

 fs/btrfs/ctree.c                 | 49 ++++++++++++++++------------------------
 fs/btrfs/ctree.h                 |  3 +--
 fs/btrfs/disk-io.c               | 26 +++++++--------------
 fs/btrfs/disk-io.h               |  2 --
 fs/btrfs/extent-tree.c           |  4 ++--
 fs/btrfs/extent_io.c             | 47 +++++++++++++++++++++++++++++++++-----
 fs/btrfs/extent_io.h             |  9 ++++++--
 fs/btrfs/file-item.c             |  2 +-
 fs/btrfs/free-space-cache.c      |  4 ++--
 fs/btrfs/inode.c                 |  2 +-
 fs/btrfs/ioctl.c                 | 10 ++++----
 fs/btrfs/reada.c                 | 24 ++++++--------------
 fs/btrfs/relocation.c            |  2 +-
 fs/btrfs/tests/extent-io-tests.c |  2 +-
 fs/btrfs/volumes.c               |  6 ++---
 15 files changed, 98 insertions(+), 94 deletions(-)