[PATCH 1/2] mm: Make task in balance_dirty_pages() killable

[Jan Kara <jack@suse.cz>]

There is no reason why task in balance_dirty_pages() shouldn't be killable
and it helps in recovering from some error conditions (like when filesystem
goes in error state and cannot accept writeback anymore but we still want to
kill processes using it to be able to unmount it).

Reported-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Tested-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 mm/page-writeback.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 0360d1b..39f5805 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1133,7 +1133,7 @@ pause:
 					  pages_dirtied,
 					  pause,
 					  start_time);
-		__set_current_state(TASK_UNINTERRUPTIBLE);
+		__set_current_state(TASK_KILLABLE);
 		io_schedule_timeout(pause);
 
 		dirty_thresh = hard_dirty_limit(dirty_thresh);
@@ -1145,6 +1145,9 @@ pause:
 		 */
 		if (nr_dirty < dirty_thresh)
 			break;
+
+		if (fatal_signal_pending(current))
+			break;
 	}
 
 	if (!dirty_exceeded && bdi->dirty_exceeded)
-- 
1.7.1