From b5e84594cafb934e023ee7d4ea4208b6c6b65fcc Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 26 Apr 2021 23:53:10 -0400 Subject: [PATCH] mm/writeback: Add folio_mark_dirty() Reimplement set_page_dirty() as a wrapper around folio_mark_dirty(). There is no change to filesystems as they were already being called with the compound_head of the page being marked dirty. We avoid several calls to compound_head(), both statically (through using folio_test_dirty() instead of PageDirty() and dynamically by calling folio_mapping() instead of page_mapping(). Also return bool instead of int to show the range of values actually returned, and add kernel-doc. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: David Howells Acked-by: Vlastimil Babka --- include/linux/mm.h | 3 ++- mm/folio-compat.c | 6 ++++++ mm/page-writeback.c | 35 +++++++++++++++++++---------------- 3 files changed, 27 insertions(+), 17 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 93d5fbe2e4e3..00510b02ffe1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2008,7 +2008,8 @@ int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page); void account_page_cleaned(struct page *page, struct address_space *mapping, struct bdi_writeback *wb); -int set_page_dirty(struct page *page); +bool folio_mark_dirty(struct folio *folio); +bool set_page_dirty(struct page *page); int set_page_dirty_lock(struct page *page); void __cancel_dirty_page(struct page *page); static inline void cancel_dirty_page(struct page *page) diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 10ce5582d869..2c2b3917b5dc 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -77,3 +77,9 @@ bool set_page_writeback(struct page *page) return folio_start_writeback(page_folio(page)); } EXPORT_SYMBOL(set_page_writeback); + +bool set_page_dirty(struct page *page) +{ + return folio_mark_dirty(page_folio(page)); +} +EXPORT_SYMBOL(set_page_dirty); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 82938b037103..c79801656f5b 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2581,18 +2581,21 @@ int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page) } EXPORT_SYMBOL(redirty_page_for_writepage); -/* - * Dirty a page. +/** + * folio_mark_dirty - Mark a folio as being modified. + * @folio: The folio. * - * For pages with a mapping this should be done under the page lock for the - * benefit of asynchronous memory errors who prefer a consistent dirty state. - * This rule can be broken in some special cases, but should be better not to. + * For folios with a mapping this should be done under the page lock + * for the benefit of asynchronous memory errors who prefer a consistent + * dirty state. This rule can be broken in some special cases, + * but should be better not to. + * + * Return: True if the folio was newly dirtied, false if it was already dirty. */ -int set_page_dirty(struct page *page) +bool folio_mark_dirty(struct folio *folio) { - struct address_space *mapping = page_mapping(page); + struct address_space *mapping = folio_mapping(folio); - page = compound_head(page); if (likely(mapping)) { /* * readahead/lru_deactivate_page could remain @@ -2604,17 +2607,17 @@ int set_page_dirty(struct page *page) * it will confuse readahead and make it restart the size rampup * process. But it's a trivial problem. */ - if (PageReclaim(page)) - ClearPageReclaim(page); - return mapping->a_ops->set_page_dirty(page); + if (folio_test_reclaim(folio)) + folio_clear_reclaim(folio); + return mapping->a_ops->set_page_dirty(&folio->page); } - if (!PageDirty(page)) { - if (!TestSetPageDirty(page)) - return 1; + if (!folio_test_dirty(folio)) { + if (!folio_test_set_dirty(folio)) + return true; } - return 0; + return false; } -EXPORT_SYMBOL(set_page_dirty); +EXPORT_SYMBOL(folio_mark_dirty); /* * set_page_dirty() is racy if the caller has no reference against