writeback: move last_active to bdi

Currently bdi threads use local variable 'last_active' which stores last time
when the bdi thread did some useful work. Move this local variable to 'struct
bdi_writeback'. This is just a preparation for the further patches which will
make the forker thread decide when bdi threads should be killed.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 57fbfd0ebc52..9f5cab75c157 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -800,12 +800,12 @@ int bdi_writeback_thread(void *data)
 {
         struct bdi_writeback *wb = data;
         struct backing_dev_info *bdi = wb->bdi;
-        unsigned long last_active = jiffies;
         unsigned long wait_jiffies = -1UL;
         long pages_written;
 
         current->flags |= PF_FLUSHER | PF_SWAPWRITE;
         set_freezable();
+        wb->last_active = jiffies;
 
         /*
          * Our parent may run at a different priority, just set us to normal
@@ -827,7 +827,7 @@ int bdi_writeback_thread(void *data)
                 trace_writeback_pages_written(pages_written);
 
                 if (pages_written)
-                        last_active = jiffies;
+                        wb->last_active = jiffies;
                 else if (wait_jiffies != -1UL) {
                         unsigned long max_idle;
 
@@ -837,7 +837,7 @@ int bdi_writeback_thread(void *data)
                          * recreated automatically.
                          */
                         max_idle = max(5UL * 60 * HZ, wait_jiffies);
-                        if (time_after(jiffies, max_idle + last_active))
+                        if (time_after(jiffies, max_idle + wb->last_active))
                                 break;
                 }