Commit b5e84594 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

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: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
parent f143f1ea

include/linux/mm.h

+2 −1
Original line number Diff line number Diff line
@@ -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)

mm/folio-compat.c

+6 −0
Original line number Diff line number Diff line
@@ -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);

mm/page-writeback.c

+19 −16
Original line number Diff line number Diff line
@@ -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 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.

 *

 * 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.

 * 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