Merge tag 'cleanup-kernel_read_write' of git://git.infradead.org/users/hch/misc

Merge tag 'cleanup-kernel_read_write' of git://git.infradead.org/users/hch/misc

Pull in-kernel read and write op cleanups from Christoph Hellwig:
 "Cleanup in-kernel read and write operations

  Reshuffle the (__)kernel_read and (__)kernel_write helpers, and ensure
  all users of in-kernel file I/O use them if they don't use iov_iter
  based methods already.

  The new WARN_ONs in combination with syzcaller already found a missing
  input validation in 9p. The fix should be on your way through the
  maintainer ASAP".

[ This is prep-work for the real changes coming 5.9 ]

* tag 'cleanup-kernel_read_write' of git://git.infradead.org/users/hch/misc:
  fs: remove __vfs_read
  fs: implement kernel_read using __kernel_read
  integrity/ima: switch to using __kernel_read
  fs: add a __kernel_read helper
  fs: remove __vfs_write
  fs: implement kernel_write using __kernel_write
  fs: check FMODE_WRITE in __kernel_write
  fs: unexport __kernel_write
  bpfilter: switch to kernel_write
  autofs: switch to kernel_write
  cachefiles: switch to kernel_write