[PATCH 1/6] writeback: remove unused nonblocking and congestion checks

[Wu Fengguang <fengguang.wu@gmail.com>]

[-- Attachment #1: writeback-remove-congested-checks-linux_fs_fs-writeback.patch --]
[-- Type: text/plain, Size: 1240 bytes --]

- no one is calling wb_writeback and write_cache_pages with
  wbc.nonblocking=1 any more
- lumpy pageout will want to do nonblocking writeback without the
  congestion wait

So remove the congestion checks as suggested by Chris.

CC: Chris Mason <chris.mason@oracle.com>
CC: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
 fs/fs-writeback.c |    9 ---------
 1 file changed, 9 deletions(-)

--- linux.orig/fs/fs-writeback.c	2009-11-27 16:35:00.000000000 +0800
+++ linux/fs/fs-writeback.c	2009-11-27 18:54:50.000000000 +0800
@@ -657,14 +657,6 @@ static void writeback_inodes_wb(struct b
 			continue;
 		}
 
-		if (wbc->nonblocking && bdi_write_congested(wb->bdi)) {
-			wbc->encountered_congestion = 1;
-			if (!is_blkdev_sb)
-				break;		/* Skip a congested fs */
-			requeue_io(inode);
-			continue;		/* Skip a congested blockdev */
-		}
-
 		/*
 		 * Was this inode dirtied after sync_sb_inodes was called?
 		 * This keeps sync from extra jobs and livelock.
@@ -787,7 +779,6 @@ static long wb_writeback(struct bdi_writ
 			break;
 
 		wbc.more_io = 0;
-		wbc.encountered_congestion = 0;
 		wbc.nr_to_write = MAX_WRITEBACK_PAGES;
 		wbc.pages_skipped = 0;
 		writeback_inodes_wb(wb, &wbc);