Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 20 insertions, 10 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 5fa63bdf52e..bbd396ac954 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -835,7 +835,6 @@ int write_cache_pages(struct address_space *mapping,
 	pgoff_t done_index;
 	int cycled;
 	int range_whole = 0;
-	long nr_to_write = wbc->nr_to_write;
 
 	pagevec_init(&pvec, 0);
 	if (wbc->range_cyclic) {
@@ -852,7 +851,22 @@ int write_cache_pages(struct address_space *mapping,
 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 			range_whole = 1;
 		cycled = 1; /* ignore range_cyclic tests */
+
+		/*
+		 * If this is a data integrity sync, cap the writeback to the
+		 * current end of file. Any extension to the file that occurs
+		 * after this is a new write and we don't need to write those
+		 * pages out to fulfil our data integrity requirements. If we
+		 * try to write them out, we can get stuck in this scan until
+		 * the concurrent writer stops adding dirty pages and extending
+		 * EOF.
+		 */
+		if (wbc->sync_mode == WB_SYNC_ALL &&
+		    wbc->range_end == LLONG_MAX) {
+			end = i_size_read(mapping->host) >> PAGE_CACHE_SHIFT;
+		}
 	}
+
 retry:
 	done_index = index;
 	while (!done && (index <= end)) {
@@ -935,11 +949,10 @@ continue_unlock:
 					done = 1;
 					break;
 				}
- 			}
+			}
 
-			if (nr_to_write > 0) {
-				nr_to_write--;
-				if (nr_to_write == 0 &&
+			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
@@ -970,11 +983,8 @@ continue_unlock:
 		end = writeback_index - 1;
 		goto retry;
 	}
-	if (!wbc->no_nrwrite_index_update) {
-		if (wbc->range_cyclic || (range_whole && nr_to_write > 0))
-			mapping->writeback_index = done_index;
-		wbc->nr_to_write = nr_to_write;
-	}
+	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
+		mapping->writeback_index = done_index;
 
 	return ret;
 }