Revert "mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio"

This reverts commit cd544fd1dc9293c6702fab6effa63dac1cc67e99.

As discussed in [1] this commit was a no-op because the mapping type was
checked in vma_to_resize before move_vma is ever called.  This meant that
vm_ops->mremap() would never be called on such mappings.  Furthermore,
we've since expanded support of MREMAP_DONTUNMAP to non-anonymous
mappings, and these special mappings are still protected by the existing
check of !VM_DONTEXPAND and !VM_PFNMAP which will result in a -EINVAL.

1. https://lkml.org/lkml/2020/12/28/2340

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Brian Geffon <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Reviewed-by: Dmitry Safonov <[email protected]>
Cc: Alejandro Colomar <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: "Kirill A . Shutemov" <[email protected]>
Cc: Lokesh Gidra <[email protected]>
Cc: Michael Kerrisk <[email protected]>
Cc: "Michael S . Tsirkin" <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Sonny Rao <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions