[PATCH] __block_write_full_page() simplification

The `last_bh' logic probably isn't worth much.  In those situations where only
the front part of the page is being written out we will save some looping but
in the vastly more common case of an all-page writeout if just adds more code.

Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/buffer.c

@@ -1751,7 +1751,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 	int err;
 	sector_t block;
 	sector_t last_block;
-	struct buffer_head *bh, *head, *last_bh = NULL;
+	struct buffer_head *bh, *head;
 	int nr_underway = 0;
 
 	BUG_ON(!PageLocked(page));
@@ -1826,7 +1826,6 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 		}
 		if (test_clear_buffer_dirty(bh)) {
 			mark_buffer_async_write(bh);
-			last_bh = bh;
 		} else {
 			unlock_buffer(bh);
 		}
@@ -1844,12 +1843,9 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 		if (buffer_async_write(bh)) {
 			submit_bh(WRITE, bh);
 			nr_underway++;
-			if (bh == last_bh)
-				break;
 		}
 		bh = next;
 	} while (bh != head);
-	bh = head;
 	unlock_page(page);
 
 	err = 0;
@@ -1892,7 +1888,6 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 		if (buffer_mapped(bh) && buffer_dirty(bh)) {
 			lock_buffer(bh);
 			mark_buffer_async_write(bh);
-			last_bh = bh;
 		} else {
 			/*
 			 * The buffer may have been set dirty during
@@ -1911,12 +1906,9 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 			clear_buffer_dirty(bh);
 			submit_bh(WRITE, bh);
 			nr_underway++;
-			if (bh == last_bh)
-				break;
 		}
 		bh = next;
 	} while (bh != head);
-	bh = head;
 	goto done;
 }