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>

1 files changed, 0 insertions, 12 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2c5d79236ead..0b19943ecf8b 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -821,7 +821,6 @@ int write_cache_pages(struct address_space *mapping,
                       struct writeback_control *wbc, writepage_t writepage,
                       void *data)
 {
-        struct backing_dev_info *bdi = mapping->backing_dev_info;
         int ret = 0;
         int done = 0;
         struct pagevec pvec;
@@ -834,11 +833,6 @@ int write_cache_pages(struct address_space *mapping,
         int range_whole = 0;
         long nr_to_write = wbc->nr_to_write;
 
-        if (wbc->nonblocking && bdi_write_congested(bdi)) {
-                wbc->encountered_congestion = 1;
-                return 0;
-        }
-
         pagevec_init(&pvec, 0);
         if (wbc->range_cyclic) {
                 writeback_index = mapping->writeback_index; /* prev offset */
@@ -957,12 +951,6 @@ continue_unlock:
                                         break;
                                 }
                         }
-
-                        if (wbc->nonblocking && bdi_write_congested(bdi)) {
-                                wbc->encountered_congestion = 1;
-                                done = 1;
-                                break;
-                        }
                 }
                 pagevec_release(&pvec);
                 cond_resched();