mm/truncate: Replace page_mapped() call in invalidate_inode_page()
authorMatthew Wilcox (Oracle) <willy@infradead.org>
Sat, 12 Feb 2022 22:43:16 +0000 (17:43 -0500)
committerMatthew Wilcox (Oracle) <willy@infradead.org>
Mon, 21 Mar 2022 16:59:01 +0000 (12:59 -0400)
commite41c81d0d30e1a6ebf408feaf561f80cac4457dc
tree4337c6160315b516d9c58241832a235f6656a93f
parent4418481396b2caeded6d0eed11ac9052ab4c0763
mm/truncate: Replace page_mapped() call in invalidate_inode_page()

folio_mapped() is expensive because it has to check each page's mapcount
field.  A cheaper check is whether there are any extra references to
the page, other than the one we own, one from the page private data and
the ones held by the page cache.

The call to remove_mapping() will fail in any case if it cannot freeze
the refcount, but failing here avoids cycling the i_pages spinlock.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
mm/truncate.c