4 files changed, 30 insertions, 21 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 1d94f15d7f0d..4b1b29ef2cb0 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -451,6 +451,7 @@ void blk_cleanup_queue(struct request_queue *q)
          */
         blk_sync_queue(q);
 
+        del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);
         mutex_lock(&q->sysfs_lock);
         queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
         mutex_unlock(&q->sysfs_lock);
@@ -511,6 +512,8 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
                 return NULL;
         }
 
+        setup_timer(&q->backing_dev_info.laptop_mode_wb_timer,
+                    laptop_mode_timer_fn, (unsigned long) q);
         init_timer(&q->unplug_timer);
         setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
         INIT_LIST_HEAD(&q->timeout_list);
@@ -2101,7 +2104,7 @@ static void blk_finish_request(struct request *req, int error)
         BUG_ON(blk_queued_rq(req));
 
         if (unlikely(laptop_mode) && blk_fs_request(req))
-                laptop_io_completion();
+                laptop_io_completion(&req->q->backing_dev_info);
 
         blk_delete_timer(req);
 
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index fcbc26af00e4..2742e1adfc30 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -14,6 +14,7 @@
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/sched.h>
+#include <linux/timer.h>
 #include <linux/writeback.h>
 #include <asm/atomic.h>
 
@@ -88,6 +89,8 @@ struct backing_dev_info {
 
         struct device *dev;
 
+        struct timer_list laptop_mode_wb_timer;
+
 #ifdef CONFIG_DEBUG_FS
         struct dentry *debug_dir;
         struct dentry *debug_stats;
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 36520ded3e06..eb38a2c645f6 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -96,8 +96,10 @@ static inline void inode_sync_wait(struct inode *inode)
 /*
  * mm/page-writeback.c
  */
-void laptop_io_completion(void);
+void laptop_io_completion(struct backing_dev_info *info);
 void laptop_sync_completion(void);
+void laptop_mode_sync(struct work_struct *work);
+void laptop_mode_timer_fn(unsigned long data);
 void throttle_vm_writeout(gfp_t gfp_mask);
 
 /* These are exported to sysctl. */
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 0b19943ecf8b..d0f2b3765f8d 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -683,10 +683,6 @@ void throttle_vm_writeout(gfp_t gfp_mask)
         }
 }
 
-static void laptop_timer_fn(unsigned long unused);
-
-static DEFINE_TIMER(laptop_mode_wb_timer, laptop_timer_fn, 0, 0);
-
 /*
  * sysctl handler for /proc/sys/vm/dirty_writeback_centisecs
  */
@@ -697,21 +693,19 @@ int dirty_writeback_centisecs_handler(ctl_table *table, int write,
         return 0;
 }
 
-static void do_laptop_sync(struct work_struct *work)
+void laptop_mode_timer_fn(unsigned long data)
 {
-        wakeup_flusher_threads(0);
-        kfree(work);
-}
+        struct request_queue *q = (struct request_queue *)data;
+        int nr_pages = global_page_state(NR_FILE_DIRTY) +
+                global_page_state(NR_UNSTABLE_NFS);
 
-static void laptop_timer_fn(unsigned long unused)
-{
-        struct work_struct *work;
+        /*
+         * We want to write everything out, not just down to the dirty
+         * threshold
+         */
 
-        work = kmalloc(sizeof(*work), GFP_ATOMIC);
-        if (work) {
-                INIT_WORK(work, do_laptop_sync);
-                schedule_work(work);
-        }
+        if (bdi_has_dirty_io(&q->backing_dev_info))
+                bdi_start_writeback(&q->backing_dev_info, NULL, nr_pages);
 }
 
 /*
@@ -719,9 +713,9 @@ static void laptop_timer_fn(unsigned long unused)
  * of all dirty data a few seconds from now.  If the flush is already scheduled
  * then push it back - the user is still using the disk.
  */
-void laptop_io_completion(void)
+void laptop_io_completion(struct backing_dev_info *info)
 {
-        mod_timer(&laptop_mode_wb_timer, jiffies + laptop_mode);
+        mod_timer(&info->laptop_mode_wb_timer, jiffies + laptop_mode);
 }
 
 /*
@@ -731,7 +725,14 @@ void laptop_io_completion(void)
  */
 void laptop_sync_completion(void)
 {
-        del_timer(&laptop_mode_wb_timer);
+        struct backing_dev_info *bdi;
+
+        rcu_read_lock();
+
+        list_for_each_entry_rcu(bdi, &bdi_list, bdi_list)
+                del_timer(&bdi->laptop_mode_wb_timer);
+
+        rcu_read_unlock();
 }
 
 /*