Merge tag 'upstream-4.9-rc1' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS updates from Richard Weinberger:
 "This pull request contains:

   - Fixes for both UBI and UBIFS
   - overlayfs support (O_TMPFILE, RENAME_WHITEOUT/EXCHANGE)
   - Code refactoring for the upcoming MLC support"

[ Ugh, we just got rid of the "rename2()" naming for the extended rename
  functionality. And this re-introduces it in ubifs with the cross-
  renaming and whiteout support.

  But rather than do any re-organizations in the merge itself, the
  naming can be cleaned up later ]

* tag 'upstream-4.9-rc1' of git://git.infradead.org/linux-ubifs: (27 commits)
  UBIFS: improve function-level documentation
  ubifs: fix host xattr_len when changing xattr
  ubifs: Use move variable in ubifs_rename()
  ubifs: Implement RENAME_EXCHANGE
  ubifs: Implement RENAME_WHITEOUT
  ubifs: Implement O_TMPFILE
  ubi: Fix Fastmap's update_vol()
  ubi: Fix races around ubi_refill_pools()
  ubi: Deal with interrupted erasures in WL
  UBI: introduce the VID buffer concept
  UBI: hide EBA internals
  UBI: provide an helper to query LEB information
  UBI: provide an helper to check whether a LEB is mapped or not
  UBI: add an helper to check lnum validity
  UBI: simplify LEB write and atomic LEB change code
  UBI: simplify recover_peb() code
  UBI: move the global ech and vidh variables into struct ubi_attach_info
  UBI: provide helpers to allocate and free aeb elements
  UBI: fastmap: use ubi_io_{read, write}_data() instead of ubi_io_{read, write}()
  UBI: fastmap: use ubi_rb_for_each_entry() in unmap_peb()
  ...

diff --cc fs/ubifs/dir.c
index 64902702b17d5220e92626f786fda9c85a6932de,ccd9128f8faf91dae49e4f87490bccb7d785d1e0..c8f60df2733eba516b189716a6b3bb3ab64520d1
--- 1/fs/ubifs/dir.c
--- 2/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@@ -1183,10 -1384,13 +1387,10 @@@ const struct inode_operations ubifs_dir
        .mkdir       = ubifs_mkdir,
        .rmdir       = ubifs_rmdir,
        .mknod       = ubifs_mknod,
-       .rename     = ubifs_rename,
 -      .rename2     = ubifs_rename2,
++      .rename      = ubifs_rename2,
        .setattr     = ubifs_setattr,
        .getattr     = ubifs_getattr,
 -      .setxattr    = generic_setxattr,
 -      .getxattr    = generic_getxattr,
        .listxattr   = ubifs_listxattr,
 -      .removexattr = generic_removexattr,
  #ifdef CONFIG_UBIFS_ATIME_SUPPORT
        .update_time = ubifs_update_time,
  #endif

diff --cc fs/ubifs/file.c
Simple merge