Pull ia64-clocksource into release branch

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

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index eec1481..63512a9 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -476,15 +476,13 @@ static void wb_kupdate(unsigned long arg)
  * sysctl handler for /proc/sys/vm/dirty_writeback_centisecs
  */
 int dirty_writeback_centisecs_handler(ctl_table *table, int write,
-               struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+       struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
 {
        proc_dointvec_userhz_jiffies(table, write, file, buffer, length, ppos);
-       if (dirty_writeback_interval) {
-               mod_timer(&wb_timer,
-                       jiffies + dirty_writeback_interval);
-               } else {
+       if (dirty_writeback_interval)
+               mod_timer(&wb_timer, jiffies + dirty_writeback_interval);
+       else
                del_timer(&wb_timer);
-       }
        return 0;
 }
 
@@ -826,6 +824,7 @@ int __set_page_dirty_nobuffers(struct page *page)
                mapping2 = page_mapping(page);
                if (mapping2) { /* Race with truncate? */
                        BUG_ON(mapping2 != mapping);
+                       WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
                        if (mapping_cap_account_dirty(mapping)) {
                                __inc_zone_page_state(page, NR_FILE_DIRTY);
                                task_io_account_write(PAGE_CACHE_SIZE);
@@ -919,6 +918,9 @@ int clear_page_dirty_for_io(struct page *page)
 {
        struct address_space *mapping = page_mapping(page);
 
+       BUG_ON(!PageLocked(page));
+
+       ClearPageReclaim(page);
        if (mapping && mapping_cap_account_dirty(mapping)) {
                /*
                 * Yes, Virginia, this is indeed insane.
@@ -944,14 +946,19 @@ int clear_page_dirty_for_io(struct page *page)
                 * We basically use the page "master dirty bit"
                 * as a serialization point for all the different
                 * threads doing their things.
-                *
-                * FIXME! We still have a race here: if somebody
-                * adds the page back to the page tables in
-                * between the "page_mkclean()" and the "TestClearPageDirty()",
-                * we might have it mapped without the dirty bit set.
                 */
                if (page_mkclean(page))
                        set_page_dirty(page);
+               /*
+                * We carefully synchronise fault handlers against
+                * installing a dirty pte and marking the page dirty
+                * at this point. We do this by having them hold the
+                * page lock at some point after installing their
+                * pte, but before marking the page dirty.
+                * Pages are always locked coming in here, so we get
+                * the desired exclusion. See mm/memory.c:do_wp_page()
+                * for more comments.
+                */
                if (TestClearPageDirty(page)) {
                        dec_zone_page_state(page, NR_FILE_DIRTY);
                        return 1;
@@ -980,6 +987,8 @@ int test_clear_page_writeback(struct page *page)
        } else {
                ret = TestClearPageWriteback(page);
        }
+       if (ret)
+               dec_zone_page_state(page, NR_WRITEBACK);
        return ret;
 }
 
@@ -1005,6 +1014,8 @@ int test_set_page_writeback(struct page *page)
        } else {
                ret = TestSetPageWriteback(page);
        }
+       if (!ret)
+               inc_zone_page_state(page, NR_WRITEBACK);
        return ret;
 
 }