writeback: fix bdi_writeback iteration in wakeup_dirtytime_writeback()

[linux-drm-fsl-dcu.git] / fs / fs-writeback.c

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 587ac08eabb62bcd47c0a90309e0442262eafd39..d0da30668e9807b705df7c1ff1380b263d536640 100644 (file)
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1481,6 +1481,21 @@ static long writeback_sb_inodes(struct super_block *sb,
                wbc_detach_inode(&wbc);
                work->nr_pages -= write_chunk - wbc.nr_to_write;
                wrote += write_chunk - wbc.nr_to_write;
+
+               if (need_resched()) {
+                       /*
+                        * We're trying to balance between building up a nice
+                        * long list of IOs to improve our merge rate, and
+                        * getting those IOs out quickly for anyone throttling
+                        * in balance_dirty_pages().  cond_resched() doesn't
+                        * unplug, so get our IOs out the door before we
+                        * give up the CPU.
+                        */
+                       blk_flush_plug(current);
+                       cond_resched();
+               }
+
+
                spin_lock(&wb->list_lock);
                spin_lock(&inode->i_lock);
                if (!(inode->i_state & I_DIRTY_ALL))
@@ -1488,7 +1503,7 @@ static long writeback_sb_inodes(struct super_block *sb,
                requeue_inode(inode, wb, &wbc);
                inode_sync_complete(inode);
                spin_unlock(&inode->i_lock);
-               cond_resched_lock(&wb->list_lock);
+
                /*
                 * bail out to wb_writeback() often enough to check
                 * background threshold and other termination conditions.
@@ -1882,8 +1897,8 @@ static void wakeup_dirtytime_writeback(struct work_struct *w)
                struct wb_iter iter;
 
                bdi_for_each_wb(wb, bdi, &iter, 0)
-                       if (!list_empty(&bdi->wb.b_dirty_time))
-                               wb_wakeup(&bdi->wb);
+                       if (!list_empty(&wb->b_dirty_time))
+                               wb_wakeup(wb);
        }
        rcu_read_unlock();
        schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ);