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

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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: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Matthew Wilcox (Oracle) 2022-02-12 15:27:42 -05:00
parent b9ccad2e5d
commit 1b8ddbeeb9
2 changed files with 6 additions and 24 deletions
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2
kernel/futex/core.c
View File

@ -302,7 +302,7 @@ again:
* found it, but truncated or holepunched or subjected to * found it, but truncated or holepunched or subjected to
* invalidate_complete_page2 before we got the page lock (also * invalidate_complete_page2 before we got the page lock (also
* cases which we are happy to fail). And we hold a reference, * 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. * prevents drop_caches from setting mapping to NULL beneath us.
* *
* The case we do have to guard against is when memory pressure made * The case we do have to guard against is when memory pressure made

28
mm/truncate.c
View File

@ -193,27 +193,6 @@ static void truncate_cleanup_folio(struct folio *folio)
folio_clear_mappedtodisk(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) int truncate_inode_folio(struct address_space *mapping, struct folio *folio)
{ {
if (folio->mapping != mapping) if (folio->mapping != mapping)
@ -309,7 +288,10 @@ int invalidate_inode_page(struct page *page)
return 0; return 0;
if (page_mapped(page)) if (page_mapped(page))
return 0; 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 * refcount. We do this because invalidate_inode_pages2() needs stronger
* invalidation guarantees, and cannot afford to leave pages behind because * invalidation guarantees, and cannot afford to leave pages behind because
* shrink_page_list() has a temp ref on them, or because they're transiently * shrink_page_list() has a temp ref on them, or because they're transiently