vfs: Add no_nrwrite_index_update writeback control flag

[safe/jmp/linux-2.6] / mm / page-writeback.c

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index e373f14..b40f6d5 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -876,6 +876,7 @@ int write_cache_pages(struct address_space *mapping,
        pgoff_t end;            /* Inclusive */
        int scanned = 0;
        int range_whole = 0;
+       long nr_to_write = wbc->nr_to_write;
 
        if (wbc->nonblocking && bdi_write_congested(bdi)) {
                wbc->encountered_congestion = 1;
@@ -939,7 +940,7 @@ retry:
                                unlock_page(page);
                                ret = 0;
                        }
-                       if (ret || (--(wbc->nr_to_write) <= 0))
+                       if (ret || (--nr_to_write <= 0))
                                done = 1;
                        if (wbc->nonblocking && bdi_write_congested(bdi)) {
                                wbc->encountered_congestion = 1;
@@ -958,8 +959,11 @@ retry:
                index = 0;
                goto retry;
        }
-       if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
-               mapping->writeback_index = index;
+       if (!wbc->no_nrwrite_index_update) {
+               if (wbc->range_cyclic || (range_whole && nr_to_write > 0))
+                       mapping->writeback_index = index;
+               wbc->nr_to_write = nr_to_write;
+       }
 
        return ret;
 }