writeback: disable periodic old data writeback for !dirty_writeback_centisecs

[net-next-2.6.git] / fs / fs-writeback.c

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 6841effa47ca8280c736da681a378caba88cc33b..760dc8d0b4ff0863326b5afcb0ba10dc19da13b9 100644 (file)
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
+#include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
@@ -851,6 +852,12 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb)
        unsigned long expired;
        long nr_pages;
 
+       /*
+        * When set to zero, disable periodic writeback
+        */
+       if (!dirty_writeback_interval)
+               return 0;
+
        expired = wb->last_old_flush +
                        msecs_to_jiffies(dirty_writeback_interval * 10);
        if (time_before(jiffies, expired))
@@ -946,8 +953,12 @@ int bdi_writeback_task(struct bdi_writeback *wb)
                                break;
                }
 
-               wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
-               schedule_timeout_interruptible(wait_jiffies);
+               if (dirty_writeback_interval) {
+                       wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
+                       schedule_timeout_interruptible(wait_jiffies);
+               } else
+                       schedule();
+
                try_to_freeze();
        }