Commit 1b8ddbee authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

mm/truncate: Inline invalidate_complete_page() into its one caller 



invalidate_inode_page() is the only caller of invalidate_complete_page()
and inlining it reveals that the first check is unnecessary (because we
hold the page locked, and we just retrieved the mapping from the page).
Actually, it does make a difference, in that tail pages no longer fail
at this check, so it's now possible to remove a tail page from a mapping.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent b9ccad2e

kernel/futex/core.c

+1 −1
Original line number Diff line number Diff line
@@ -302,7 +302,7 @@ int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key, 
	 * found it, but truncated or holepunched or subjected to

	 * invalidate_complete_page2 before we got the page lock (also

	 * cases which we are happy to fail).  And we hold a reference,

	 * so refcount care in invalidate_complete_page's remove_mapping

	 * so refcount care in invalidate_inode_page's remove_mapping

	 * prevents drop_caches from setting mapping to NULL beneath us.

	 *

	 * The case we do have to guard against is when memory pressure made

mm/truncate.c

+5 −23
Original line number Diff line number Diff line
@@ -193,27 +193,6 @@ static void truncate_cleanup_folio(struct folio *folio) 
	folio_clear_mappedtodisk(folio);

}



/*

 * This is for invalidate_mapping_pages().  That function can be called at

 * any time, and is not supposed to throw away dirty pages.  But pages can

 * be marked dirty at any time too, so use remove_mapping which safely

 * discards clean, unused pages.

 *

 * Returns non-zero if the page was successfully invalidated.

 */

static int

invalidate_complete_page(struct address_space *mapping, struct page *page)

{



	if (page->mapping != mapping)

		return 0;



	if (page_has_private(page) && !try_to_release_page(page, 0))

		return 0;



	return remove_mapping(mapping, page);

}



int truncate_inode_folio(struct address_space *mapping, struct folio *folio)

{

	if (folio->mapping != mapping)
@@ -309,7 +288,10 @@ int invalidate_inode_page(struct page *page) 
		return 0;

	if (page_mapped(page))

		return 0;

	return invalidate_complete_page(mapping, page);

	if (page_has_private(page) && !try_to_release_page(page, 0))

		return 0;



	return remove_mapping(mapping, page);

}



/**
@@ -584,7 +566,7 @@ void invalidate_mapping_pagevec(struct address_space *mapping, 
}



/*

 * This is like invalidate_complete_page(), except it ignores the page's

 * This is like invalidate_inode_page(), except it ignores the page's

 * refcount.  We do this because invalidate_inode_pages2() needs stronger

 * invalidation guarantees, and cannot afford to leave pages behind because

 * shrink_page_list() has a temp ref on them, or because they're transiently