Merge branch 'next' into for-linus

Prepare input updates for 4.17 merge window.

1 files changed, 5 insertions, 3 deletions

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index afa37f807f12..894e5d125de6 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -81,11 +81,14 @@ struct buffer_head {
 /*
  * macro tricks to expand the set_buffer_foo(), clear_buffer_foo()
  * and buffer_foo() functions.
+ * To avoid reset buffer flags that are already set, because that causes
+ * a costly cache line transition, check the flag first.
  */
 #define BUFFER_FNS(bit, name)						\
 static __always_inline void set_buffer_##name(struct buffer_head *bh)	\
 {									\
-	set_bit(BH_##bit, &(bh)->b_state);				\
+	if (!test_bit(BH_##bit, &(bh)->b_state))			\
+		set_bit(BH_##bit, &(bh)->b_state);			\
 }									\
 static __always_inline void clear_buffer_##name(struct buffer_head *bh)	\
 {									\
@@ -151,13 +154,12 @@ void buffer_check_dirty_writeback(struct page *page,
 
 void mark_buffer_dirty(struct buffer_head *bh);
 void mark_buffer_write_io_error(struct buffer_head *bh);
-void init_buffer(struct buffer_head *, bh_end_io_t *, void *);
 void touch_buffer(struct buffer_head *bh);
 void set_bh_page(struct buffer_head *bh,
 		struct page *page, unsigned long offset);
 int try_to_free_buffers(struct page *);
 struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
-		int retry);
+		bool retry);
 void create_empty_buffers(struct page *, unsigned long,
 			unsigned long b_state);
 void end_buffer_read_sync(struct buffer_head *bh, int uptodate);