writeback: remove unused nonblocking and congestion checks
Wu Fengguang [Thu, 3 Dec 2009 12:54:25 +0000 (13:54 +0100)]
- 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>

drivers/staging/pohmelfs/inode.c
fs/fs-writeback.c
fs/xfs/linux-2.6/xfs_aops.c
mm/page-writeback.c

index c94de31..f69b778 100644 (file)
@@ -143,7 +143,6 @@ static int pohmelfs_writepages(struct address_space *mapping, struct writeback_c
        struct inode *inode = mapping->host;
        struct pohmelfs_inode *pi = POHMELFS_I(inode);
        struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb);
-       struct backing_dev_info *bdi = mapping->backing_dev_info;
        int err = 0;
        int done = 0;
        int nr_pages;
@@ -152,11 +151,6 @@ static int pohmelfs_writepages(struct address_space *mapping, struct writeback_c
        int scanned = 0;
        int range_whole = 0;
 
-       if (wbc->nonblocking && bdi_write_congested(bdi)) {
-               wbc->encountered_congestion = 1;
-               return 0;
-       }
-
        if (wbc->range_cyclic) {
                index = mapping->writeback_index; /* Start from prev offset */
                end = -1;
@@ -248,10 +242,6 @@ retry:
 
                        if (wbc->nr_to_write <= 0)
                                done = 1;
-                       if (wbc->nonblocking && bdi_write_congested(bdi)) {
-                               wbc->encountered_congestion = 1;
-                               done = 1;
-                       }
 
                        continue;
 out_continue:
index 0793961..49bc1b8 100644 (file)
@@ -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);
index c2e30ee..70f9898 100644 (file)
@@ -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);
        }
index 2c5d792..0b19943 100644 (file)
@@ -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();