1 files changed, 10 insertions, 9 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index bb553c3e955d..7b0dcea4935b 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -265,18 +265,19 @@ static void bdi_writeout_fraction(struct backing_dev_info *bdi,
  * This avoids exceeding the total dirty_limit when the floating averages
  * fluctuate too quickly.
  */
-static void
-clip_bdi_dirty_limit(struct backing_dev_info *bdi, long dirty, long *pbdi_dirty)
+static void clip_bdi_dirty_limit(struct backing_dev_info *bdi,
+                unsigned long dirty, unsigned long *pbdi_dirty)
 {
-        long avail_dirty;
+        unsigned long avail_dirty;
 
-        avail_dirty = dirty -
-                (global_page_state(NR_FILE_DIRTY) +
+        avail_dirty = global_page_state(NR_FILE_DIRTY) +
                  global_page_state(NR_WRITEBACK) +
                  global_page_state(NR_UNSTABLE_NFS) +
-                 global_page_state(NR_WRITEBACK_TEMP));
+                 global_page_state(NR_WRITEBACK_TEMP);
 
-        if (avail_dirty < 0)
+        if (avail_dirty < dirty)
+                avail_dirty = dirty - avail_dirty;
+        else
                 avail_dirty = 0;
 
         avail_dirty += bdi_stat(bdi, BDI_RECLAIMABLE) +
@@ -299,10 +300,10 @@ static inline void task_dirties_fraction(struct task_struct *tsk,
  *
  *   dirty -= (dirty/8) * p_{t}
  */
-static void task_dirty_limit(struct task_struct *tsk, long *pdirty)
+static void task_dirty_limit(struct task_struct *tsk, unsigned long *pdirty)
 {
         long numerator, denominator;
-        long dirty = *pdirty;
+        unsigned long dirty = *pdirty;
         u64 inv = dirty >> 3;
 
         task_dirties_fraction(tsk, &numerator, &denominator);