When reclaim encounters dirty file pages on the LRU lists, it wakes up
flusher threads to clean pages belonging to old inodes. In the event the
inode has dirty pages on multiple zones, the flusher threads may exit before
pages within the zone of interest are clean. This patch accounts for the
zone page reclaim is interested in.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
---
 fs/fs-writeback.c         |   35 ++++++++++++++++++++++++++++-------
 include/linux/writeback.h |    6 +++++-
 mm/page-writeback.c       |   12 +++++++++++-
 mm/vmscan.c               |    9 +++++----
 4 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 0912f93..cc52322 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -40,8 +40,10 @@ int nr_pdflush_threads;
  */
 struct wb_writeback_work {
 	long nr_pages;
+	long nr_zone_pages;
 	struct super_block *sb;
 	enum writeback_sync_modes sync_mode;
+	struct zone *zone;
 	unsigned int for_kupdate:1;
 	unsigned int range_cyclic:1;
 	unsigned int for_background:1;
@@ -85,6 +87,7 @@ static void bdi_queue_work(struct backing_dev_info *bdi,
 
 static void
 __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
+		struct zone *zone,
 		bool range_cyclic, bool for_background)
 {
 	struct wb_writeback_work *work;
@@ -104,6 +107,10 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
 	work->nr_pages	= nr_pages;
 	work->range_cyclic = range_cyclic;
 	work->for_background = for_background;
+	if (zone) {
+		work->zone = zone;
+		work->nr_zone_pages = nr_pages;
+	}
 
 	bdi_queue_work(bdi, work);
 }
@@ -121,7 +128,7 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
  */
 void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages)
 {
-	__bdi_start_writeback(bdi, nr_pages, true, false);
+	__bdi_start_writeback(bdi, nr_pages, NULL, true, false);
 }
 
 /**
@@ -135,7 +142,7 @@ void bdi_start_writeback(struct backing_dev_info *bdi, long ...
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