3 files changed, 40 insertions, 28 deletions

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 707d0dc6da0f..660a87a22511 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -48,7 +48,6 @@ static struct timer_list sync_supers_timer;
 
 static int bdi_sync_supers(void *);
 static void sync_supers_timer_fn(unsigned long);
-static void arm_supers_timer(void);
 
 static void bdi_add_default_flusher_task(struct backing_dev_info *bdi);
 
@@ -252,7 +251,7 @@ static int __init default_bdi_init(void)
 
         init_timer(&sync_supers_timer);
         setup_timer(&sync_supers_timer, sync_supers_timer_fn, 0);
-        arm_supers_timer();
+        bdi_arm_supers_timer();
 
         err = bdi_init(&default_backing_dev_info);
         if (!err)
@@ -374,10 +373,13 @@ static int bdi_sync_supers(void *unused)
         return 0;
 }
 
-static void arm_supers_timer(void)
+void bdi_arm_supers_timer(void)
 {
         unsigned long next;
 
+        if (!dirty_writeback_interval)
+                return;
+
         next = msecs_to_jiffies(dirty_writeback_interval * 10) + jiffies;
         mod_timer(&sync_supers_timer, round_jiffies_up(next));
 }
@@ -385,7 +387,7 @@ static void arm_supers_timer(void)
 static void sync_supers_timer_fn(unsigned long unused)
 {
         wake_up_process(sync_supers_tsk);
-        arm_supers_timer();
+        bdi_arm_supers_timer();
 }
 
 static int bdi_forker_task(void *ptr)
@@ -428,7 +430,10 @@ static int bdi_forker_task(void *ptr)
 
                         spin_unlock_bh(&bdi_lock);
                         wait = msecs_to_jiffies(dirty_writeback_interval * 10);
-                        schedule_timeout(wait);
+                        if (wait)
+                                schedule_timeout(wait);
+                        else
+                                schedule();
                         try_to_freeze();
                         continue;
                 }
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 0b19943ecf8b..b289310e2c89 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -597,7 +597,7 @@ static void balance_dirty_pages(struct address_space *mapping,
             (!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
                                + global_page_state(NR_UNSTABLE_NFS))
                                           > background_thresh)))
-                bdi_start_writeback(bdi, NULL, 0);
+                bdi_start_writeback(bdi, NULL, 0, 0);
 }
 
 void set_page_dirty_balance(struct page *page, int page_mkwrite)
@@ -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
  */
@@ -694,24 +690,24 @@ int dirty_writeback_centisecs_handler(ctl_table *table, int write,
         void __user *buffer, size_t *length, loff_t *ppos)
 {
         proc_dointvec(table, write, buffer, length, ppos);
+        bdi_arm_supers_timer();
         return 0;
 }
 
-static void do_laptop_sync(struct work_struct *work)
+#ifdef CONFIG_BLOCK
+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, 0);
 }
 
 /*
@@ -719,9 +715,9 @@ 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);
 }
 
 /*
@@ -731,8 +727,16 @@ 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();
 }
+#endif
 
 /*
  * If ratelimit_pages is too high then we can get into dirty-data overload
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 6cd0a8f90dc7..eb086e0f4dcc 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -139,7 +139,8 @@ static int discard_swap(struct swap_info_struct *si)
         nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
         if (nr_blocks) {
                 err = blkdev_issue_discard(si->bdev, start_block,
-                                nr_blocks, GFP_KERNEL, DISCARD_FL_BARRIER);
+                                nr_blocks, GFP_KERNEL,
+                                BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
                 if (err)
                         return err;
                 cond_resched();
@@ -150,7 +151,8 @@ static int discard_swap(struct swap_info_struct *si)
                 nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9);
 
                 err = blkdev_issue_discard(si->bdev, start_block,
-                                nr_blocks, GFP_KERNEL, DISCARD_FL_BARRIER);
+                                nr_blocks, GFP_KERNEL,
+                                BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
                 if (err)
                         break;
 
@@ -189,7 +191,8 @@ static void discard_swap_cluster(struct swap_info_struct *si,
                         start_block <<= PAGE_SHIFT - 9;
                         nr_blocks <<= PAGE_SHIFT - 9;
                         if (blkdev_issue_discard(si->bdev, start_block,
-                                    nr_blocks, GFP_NOIO, DISCARD_FL_BARRIER))
+                                    nr_blocks, GFP_NOIO, BLKDEV_IFL_WAIT |
+                                                        BLKDEV_IFL_BARRIER))
                                 break;
                 }