Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...

[pandora-kernel.git] / mm / page-writeback.c

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 20890d8..e3bccac 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -397,7 +397,7 @@ unsigned long determine_dirtyable_memory(void)
        return x + 1;   /* Ensure that we never return 0 */
 }
 
-/**
+/*
  * global_dirty_limits - background-writeback and dirty-throttling thresholds
  *
  * Calculate the dirty thresholds based on sysctl parameters
@@ -440,7 +440,7 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty)
        *pdirty = dirty;
 }
 
-/**
+/*
  * bdi_dirty_limit - @bdi's share of dirty throttling threshold
  *
  * Allocate high/low dirty limits to fast/slow devices, in order to prevent
@@ -836,7 +836,8 @@ void tag_pages_for_writeback(struct address_space *mapping,
                spin_unlock_irq(&mapping->tree_lock);
                WARN_ON_ONCE(tagged > WRITEBACK_TAG_BATCH);
                cond_resched();
-       } while (tagged >= WRITEBACK_TAG_BATCH);
+               /* We check 'start' to handle wrapping when end == ~0UL */
+       } while (tagged >= WRITEBACK_TAG_BATCH && start);
 }
 EXPORT_SYMBOL(tag_pages_for_writeback);
 
@@ -984,22 +985,16 @@ continue_unlock:
                                }
                        }
 
-                       if (wbc->nr_to_write > 0) {
-                               if (--wbc->nr_to_write == 0 &&
-                                   wbc->sync_mode == WB_SYNC_NONE) {
-                                       /*
-                                        * We stop writing back only if we are
-                                        * not doing integrity sync. In case of
-                                        * integrity sync we have to keep going
-                                        * because someone may be concurrently
-                                        * dirtying pages, and we might have
-                                        * synced a lot of newly appeared dirty
-                                        * pages, but have not synced all of the
-                                        * old dirty pages.
-                                        */
-                                       done = 1;
-                                       break;
-                               }
+                       /*
+                        * We stop writing back only if we are not doing
+                        * integrity sync. In case of integrity sync we have to
+                        * keep going until we have written all the pages
+                        * we tagged for writeback prior to entering this loop.
+                        */
+                       if (--wbc->nr_to_write <= 0 &&
+                           wbc->sync_mode == WB_SYNC_NONE) {
+                               done = 1;
+                               break;
                        }
                }
                pagevec_release(&pvec);
@@ -1131,6 +1126,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
                task_io_account_write(PAGE_CACHE_SIZE);
        }
 }
+EXPORT_SYMBOL(account_page_dirtied);
 
 /*
  * For address_spaces which do not use buffers.  Just tag the page as dirty in