3 files changed, 9 insertions, 3 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 414df43706c7..71c158ac60a3 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -473,6 +473,8 @@ sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
                 if (wbc->nr_to_write <= 0)
                         break;
         }
+        if (!list_empty(&sb->s_more_io))
+                wbc->more_io = 1;
         return;         /* Leave any unwritten inodes on s_io */
 }
 
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 52be879793ed..1200868a5dee 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -62,6 +62,7 @@ struct writeback_control {
         unsigned for_reclaim:1;         /* Invoked from the page allocator */
         unsigned for_writepages:1;      /* This is a writepages() call */
         unsigned range_cyclic:1;        /* range_start is cyclic */
+        unsigned more_io:1;             /* more io to be dispatched */
 };
 
 /*
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 334852131588..bcdbbf6c4a85 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -553,6 +553,7 @@ static void background_writeout(unsigned long _min_pages)
                         global_page_state(NR_UNSTABLE_NFS) < background_thresh
                                 && min_pages <= 0)
                         break;
+                wbc.more_io = 0;
                 wbc.encountered_congestion = 0;
                 wbc.nr_to_write = MAX_WRITEBACK_PAGES;
                 wbc.pages_skipped = 0;
@@ -560,8 +561,9 @@ static void background_writeout(unsigned long _min_pages)
                 min_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
                 if (wbc.nr_to_write > 0 || wbc.pages_skipped > 0) {
                         /* Wrote less than expected */
-                        congestion_wait(WRITE, HZ/10);
-                        if (!wbc.encountered_congestion)
+                        if (wbc.encountered_congestion || wbc.more_io)
+                                congestion_wait(WRITE, HZ/10);
+                        else
                                 break;
                 }
         }
@@ -626,11 +628,12 @@ static void wb_kupdate(unsigned long arg)
                         global_page_state(NR_UNSTABLE_NFS) +
                         (inodes_stat.nr_inodes - inodes_stat.nr_unused);
         while (nr_to_write > 0) {
+                wbc.more_io = 0;
                 wbc.encountered_congestion = 0;
                 wbc.nr_to_write = MAX_WRITEBACK_PAGES;
                 writeback_inodes(&wbc);
                 if (wbc.nr_to_write > 0) {
-                        if (wbc.encountered_congestion)
+                        if (wbc.encountered_congestion || wbc.more_io)
                                 congestion_wait(WRITE, HZ/10);
                         else
                                 break;  /* All the old data is written */