writeback: make wakeup_dirtytime_writeback() handle multiple bdi_writeback's
wakeup_dirtytime_writeback() currently only starts writeback on the
root wb (bdi_writeback). For cgroup writeback support, update the
function to check all wbs.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 508e10c..8ae212e 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1260,9 +1260,12 @@
rcu_read_lock();
list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) {
- if (list_empty(&bdi->wb.b_dirty_time))
- continue;
- wb_wakeup(&bdi->wb);
+ struct bdi_writeback *wb;
+ struct wb_iter iter;
+
+ bdi_for_each_wb(wb, bdi, &iter, 0)
+ if (!list_empty(&bdi->wb.b_dirty_time))
+ wb_wakeup(&bdi->wb);
}
rcu_read_unlock();
schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ);