nilfs2: use BIT() macro

Replace bit shifts by BIT macro for clarity.

Link: http://lkml.kernel.org/r/1465825507-3407-3-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index eaccf12..f11a3ad 100644
--- a/fs/nilfs2/page.c
+++ b/fs/nilfs2/page.c
@@ -30,9 +30,9 @@
 #include "mdt.h"
 
 
-#define NILFS_BUFFER_INHERENT_BITS  \
-	((1UL << BH_Uptodate) | (1UL << BH_Mapped) | (1UL << BH_NILFS_Node) | \
-	 (1UL << BH_NILFS_Volatile) | (1UL << BH_NILFS_Checked))
+#define NILFS_BUFFER_INHERENT_BITS					\
+	(BIT(BH_Uptodate) | BIT(BH_Mapped) | BIT(BH_NILFS_Node) |	\
+	 BIT(BH_NILFS_Volatile) | BIT(BH_NILFS_Checked))
 
 static struct buffer_head *
 __nilfs_get_page_block(struct page *page, unsigned long block, pgoff_t index,
@@ -85,9 +85,9 @@
 {
 	struct page *page = bh->b_page;
 	const unsigned long clear_bits =
-		(1 << BH_Uptodate | 1 << BH_Dirty | 1 << BH_Mapped |
-		 1 << BH_Async_Write | 1 << BH_NILFS_Volatile |
-		 1 << BH_NILFS_Checked | 1 << BH_NILFS_Redirected);
+		(BIT(BH_Uptodate) | BIT(BH_Dirty) | BIT(BH_Mapped) |
+		 BIT(BH_Async_Write) | BIT(BH_NILFS_Volatile) |
+		 BIT(BH_NILFS_Checked) | BIT(BH_NILFS_Redirected));
 
 	lock_buffer(bh);
 	set_mask_bits(&bh->b_state, clear_bits, 0);
@@ -124,17 +124,17 @@
 	dbh->b_bdev = sbh->b_bdev;
 
 	bh = dbh;
-	bits = sbh->b_state & ((1UL << BH_Uptodate) | (1UL << BH_Mapped));
+	bits = sbh->b_state & (BIT(BH_Uptodate) | BIT(BH_Mapped));
 	while ((bh = bh->b_this_page) != dbh) {
 		lock_buffer(bh);
 		bits &= bh->b_state;
 		unlock_buffer(bh);
 	}
-	if (bits & (1UL << BH_Uptodate))
+	if (bits & BIT(BH_Uptodate))
 		SetPageUptodate(dpage);
 	else
 		ClearPageUptodate(dpage);
-	if (bits & (1UL << BH_Mapped))
+	if (bits & BIT(BH_Mapped))
 		SetPageMappedToDisk(dpage);
 	else
 		ClearPageMappedToDisk(dpage);
@@ -215,7 +215,7 @@
 		create_empty_buffers(dst, sbh->b_size, 0);
 
 	if (copy_dirty)
-		mask |= (1UL << BH_Dirty);
+		mask |= BIT(BH_Dirty);
 
 	dbh = dbufs = page_buffers(dst);
 	do {
@@ -414,9 +414,9 @@
 	if (page_has_buffers(page)) {
 		struct buffer_head *bh, *head;
 		const unsigned long clear_bits =
-			(1 << BH_Uptodate | 1 << BH_Dirty | 1 << BH_Mapped |
-			 1 << BH_Async_Write | 1 << BH_NILFS_Volatile |
-			 1 << BH_NILFS_Checked | 1 << BH_NILFS_Redirected);
+			(BIT(BH_Uptodate) | BIT(BH_Dirty) | BIT(BH_Mapped) |
+			 BIT(BH_Async_Write) | BIT(BH_NILFS_Volatile) |
+			 BIT(BH_NILFS_Checked) | BIT(BH_NILFS_Redirected));
 
 		bh = head = page_buffers(page);
 		do {