writeback: fix break condition
Commit dcf6a79dda5cc2a2bec183e50d829030c0972aaa ("write-back: fix
nr_to_write counter") fixed nr_to_write counter, but didn't set the break
condition properly.
If nr_to_write == 0 after being decremented it will loop one more time
before setting done = 1 and breaking the loop.
[akpm@linux-foundation.org: coding-style fixes]
Cc: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index c17005e..6106a5c 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1051,20 +1051,23 @@
}
}
- if (nr_to_write > 0)
+ if (nr_to_write > 0) {
nr_to_write--;
- else if (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;
+ if (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;
+ }
}
if (wbc->nonblocking && bdi_write_congested(bdi)) {