[PATCH v10 27/33] mm/writeback: Add folio_wait_stable
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: 2021-05-11 22:07:34
Also in:
linux-fsdevel, lkml
Subsystem:
memory management, memory management - core, page cache, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Matthew Wilcox, Linus Torvalds
Move wait_for_stable_page() into the folio compatibility file. folio_wait_stable() avoids a call to compound_head() and is 14 bytes smaller than wait_for_stable_page() was. The net text size grows by 24 bytes as a result of this patch. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@kernel.org> --- include/linux/pagemap.h | 1 + mm/folio-compat.c | 6 ++++++ mm/page-writeback.c | 24 ++++++++++++++---------- 3 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 417efd7edd19..06b69cd03da3 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h@@ -757,6 +757,7 @@ int folio_wait_writeback_killable(struct folio *folio); void end_page_writeback(struct page *page); void folio_end_writeback(struct folio *folio); void wait_for_stable_page(struct page *page); +void folio_wait_stable(struct folio *folio); void page_endio(struct page *page, bool is_write, int err);
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 41275dac7a92..3c83f03b80d7 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c@@ -29,3 +29,9 @@ void wait_on_page_writeback(struct page *page) return folio_wait_writeback(page_folio(page)); } EXPORT_SYMBOL_GPL(wait_on_page_writeback); + +void wait_for_stable_page(struct page *page) +{ + return folio_wait_stable(page_folio(page)); +} +EXPORT_SYMBOL_GPL(wait_for_stable_page);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index d7ac428df68a..003b85813f7c 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c@@ -2860,17 +2860,21 @@ int folio_wait_writeback_killable(struct folio *folio) EXPORT_SYMBOL_GPL(folio_wait_writeback_killable); /** - * wait_for_stable_page() - wait for writeback to finish, if necessary. - * @page: The page to wait on. + * folio_wait_stable() - wait for writeback to finish, if necessary. + * @folio: The folio to wait on. * - * This function determines if the given page is related to a backing device - * that requires page contents to be held stable during writeback. If so, then - * it will wait for any pending writeback to complete. + * This function determines if the given folio is related to a backing + * device that requires folio contents to be held stable during writeback. + * If so, then it will wait for any pending writeback to complete. + * + * Context: Sleeps. Must be called in process context and with + * no spinlocks held. Caller should hold a reference on the folio. + * If the folio is not locked, writeback may start again after writeback + * has finished. */ -void wait_for_stable_page(struct page *page) +void folio_wait_stable(struct folio *folio) { - page = thp_head(page); - if (page->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES) - wait_on_page_writeback(page); + if (folio->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES) + folio_wait_writeback(folio); } -EXPORT_SYMBOL_GPL(wait_for_stable_page); +EXPORT_SYMBOL_GPL(folio_wait_stable);
--
2.30.2