From a6de4b4873e1e352f5029b0f5b3c347427d74ab4 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Tue, 13 Oct 2020 16:51:34 -0700 Subject: [PATCH] mm: convert find_get_entry to return the head page There are only four callers remaining of find_get_entry(). get_shadow_from_swap_cache() only wants to see shadow entries and doesn't care about which page is returned. Push the find_subpage() call into find_lock_entry(), find_get_incore_page() and pagecache_get_page(). [willy@infradead.org: fix oops] Link: https://lkml.kernel.org/r/20200914112738.GM6583@casper.infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Cc: Alexey Dobriyan Cc: Chris Wilson Cc: Huang Ying Cc: Hugh Dickins Cc: Jani Nikula Cc: Johannes Weiner Cc: Matthew Auld Cc: William Kucharski Link: https://lkml.kernel.org/r/20200910183318.20139-7-willy@infradead.org Signed-off-by: Linus Torvalds --- mm/filemap.c | 13 +++++++------ mm/swap_state.c | 4 +++- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 089a2f02067f..9457d4f8b1c1 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1645,19 +1645,19 @@ EXPORT_SYMBOL(page_cache_prev_miss); /** * find_get_entry - find and get a page cache entry * @mapping: the address_space to search - * @offset: the page cache index + * @index: The page cache index. * * Looks up the page cache slot at @mapping & @offset. If there is a - * page cache page, it is returned with an increased refcount. + * page cache page, the head page is returned with an increased refcount. * * If the slot holds a shadow entry of a previously evicted page, or a * swap entry from shmem/tmpfs, it is returned. * - * Return: the found page or shadow entry, %NULL if nothing is found. + * Return: The head page or shadow entry, %NULL if nothing is found. */ -struct page *find_get_entry(struct address_space *mapping, pgoff_t offset) +struct page *find_get_entry(struct address_space *mapping, pgoff_t index) { - XA_STATE(xas, &mapping->i_pages, offset); + XA_STATE(xas, &mapping->i_pages, index); struct page *page; rcu_read_lock(); @@ -1685,7 +1685,6 @@ struct page *find_get_entry(struct address_space *mapping, pgoff_t offset) put_page(page); goto repeat; } - page = find_subpage(page, offset); out: rcu_read_unlock(); @@ -1722,6 +1721,7 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset) put_page(page); goto repeat; } + page = find_subpage(page, offset); VM_BUG_ON_PAGE(page_to_pgoff(page) != offset, page); } return page; @@ -1768,6 +1768,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, page = NULL; if (!page) goto no_page; + page = find_subpage(page, index); if (fgp_flags & FGP_LOCK) { if (fgp_flags & FGP_NOWAIT) { diff --git a/mm/swap_state.c b/mm/swap_state.c index c79e2242dd04..f24f2cea4238 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -431,8 +431,10 @@ struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index) struct swap_info_struct *si; struct page *page = find_get_entry(mapping, index); - if (!xa_is_value(page)) + if (!page) return page; + if (!xa_is_value(page)) + return find_subpage(page, index); if (!shmem_mapping(mapping)) return NULL;