[PATCH v5 02/27] mm/writeback: Add wait_on_page_writeback_killable

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

This is the killable version of wait_on_page_writeback.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 include/linux/pagemap.h |  1 +
 mm/page-writeback.c     | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 139678f382ff..8c844ba67785 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -698,6 +698,7 @@ static inline int wait_on_page_locked_killable(struct page *page)
 
 int put_and_wait_on_page_locked(struct page *page, int state);
 void wait_on_page_writeback(struct page *page);
+int wait_on_page_writeback_killable(struct page *page);
 extern void end_page_writeback(struct page *page);
 void wait_for_stable_page(struct page *page);
 
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index f6c2c3165d4d..5e761fb62800 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2830,6 +2830,22 @@ void wait_on_page_writeback(struct page *page)
 }
 EXPORT_SYMBOL_GPL(wait_on_page_writeback);
 
+/*
+ * Wait for a page to complete writeback.  Returns -EINTR if we get a
+ * fatal signal while waiting.
+ */
+int wait_on_page_writeback_killable(struct page *page)
+{
+	while (PageWriteback(page)) {
+		trace_wait_on_page_writeback(page, page_mapping(page));
+		if (wait_on_page_bit_killable(page, PG_writeback))
+			return -EINTR;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(wait_on_page_writeback_killable);
+
 /**
  * wait_for_stable_page() - wait for writeback to finish, if necessary.
  * @page:	The page to wait on.
-- 
2.30.2