---

yaml
---
r: 70723
b: refs/heads/master
c: 6610a0b
h: refs/heads/master
i:
  70721: af1fe5c
  70719: b8bfced
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2b0172e1c6e6aea0a4efcfaaab38d4a02046f45a
+refs/heads/master: 6610a0bc8dcc120daa1d93807d470d5cbf777c39

trunk/fs/fs-writeback.c

@@ -140,6 +140,30 @@ static int write_inode(struct inode *inode, int sync)
 	return 0;
 }
 
+/*
+ * Redirty an inode: set its when-it-was dirtied timestamp and move it to the
+ * furthest end of its superblock's dirty-inode list.
+ *
+ * Before stamping the inode's ->dirtied_when, we check to see whether it is
+ * already the most-recently-dirtied inode on the s_dirty list.  If that is
+ * the case then the inode must have been redirtied while it was being written
+ * out and we don't reset its dirtied_when.
+ */
+static void redirty_tail(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+
+	if (!list_empty(&sb->s_dirty)) {
+		struct inode *tail_inode;
+
+		tail_inode = list_entry(sb->s_dirty.next, struct inode, i_list);
+		if (!time_after_eq(inode->dirtied_when,
+				tail_inode->dirtied_when))
+			inode->dirtied_when = jiffies;
+	}
+	list_move(&inode->i_list, &sb->s_dirty);
+}
+
 /*
  * Write a single inode's dirty pages and inode data out to disk.
  * If `wait' is set, wait on the writeout.
@@ -219,7 +243,7 @@ __sync_single_inode(struct inode *inode, struct writeback_control *wbc)
 			 * Someone redirtied the inode while were writing back
 			 * the pages.
 			 */
-			list_move(&inode->i_list, &sb->s_dirty);
+			redirty_tail(inode);
 		} else if (atomic_read(&inode->i_count)) {
 			/*
 			 * The inode is clean, inuse