writeback: remove unused nonblocking and congestion checks

- 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.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Alex Elder <aelder@sgi.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 1 insertions, 17 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 0793961f7699..49bc1b8e8f19 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -639,14 +639,6 @@ static void writeback_inodes_wb(struct bdi_writeback *wb,
                         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.
@@ -770,7 +762,6 @@ static long wb_writeback(struct bdi_writeback *wb,
                         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);
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index c2e30eea74dc..70f989895d15 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -904,16 +904,9 @@ xfs_convert_page(
 
         if (startio) {
                 if (count) {
-                        struct backing_dev_info *bdi;
-
-                        bdi = inode->i_mapping->backing_dev_info;
                         wbc->nr_to_write--;
-                        if (bdi_write_congested(bdi)) {
-                                wbc->encountered_congestion = 1;
-                                done = 1;
-                        } else if (wbc->nr_to_write <= 0) {
+                        if (wbc->nr_to_write <= 0)
                                 done = 1;
-                        }
                 }
                 xfs_start_page_writeback(page, !page_dirty, count);
         }