mm: rmap: fix cache flush on THP pages

mm: rmap: fix cache flush on THP pages

Patch series "Fix some bugs related to ramp and dax", v7.

Patch 1-2 fix a cache flush bug, because subsequent patches depend on
those on those changes, there are placed in this series.  Patch 3-4 are
preparation for fixing a dax bug in patch 5.  Patch 6 is code cleanup
since the previous patch removes the usage of follow_invalidate_pte().

This patch (of 6):

The flush_cache_page() only remove a PAGE_SIZE sized range from the cache.
However, it does not cover the full pages in a THP except a head page.
Replace it with flush_cache_range() to fix this issue.  At least, no
problems were found due to this.  Maybe because the architectures that
have virtual indexed caches is less.

Link: https://lkml.kernel.org/r/20220403053957.10770-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20220403053957.10770-2-songmuchun@bytedance.com
Fixes: f27176cfc363 ("mm: convert page_mkclean_one() to use page_vma_mapped_walk()")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>