X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=mm%2Fpage-writeback.c;h=44720363374cb24ca3e90cb48db64d99e5bbdb5b;hb=59a00adbd30ed5d3a97ac41ad9e4b040a111eea8;hp=886ea0d5a1368af3f86548c44562896630d31c6b;hpb=49c13b51a15f1ba9f6d47e26e4a3886c4f3931e2;p=cascardo%2Flinux.git

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 886ea0d5a136..44720363374c 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -274,9 +274,9 @@ static void balance_dirty_pages(struct address_space *mapping)
 		pdflush_operation(background_writeout, 0);
 }
 
-void set_page_dirty_balance(struct page *page)
+void set_page_dirty_balance(struct page *page, int page_mkwrite)
 {
-	if (set_page_dirty(page)) {
+	if (set_page_dirty(page) || page_mkwrite) {
 		struct address_space *mapping = page_mapping(page);
 
 		if (mapping)
@@ -918,6 +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.
@@ -943,14 +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;
@@ -979,6 +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;
 }
 
@@ -1004,6 +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;
 
 }