fs/fs-writeback.c | 58 +++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 48 insertions(+), 10 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 3be57189efd5..3dcc8b202a40 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1206,6 +1206,52 @@ out_unlock_inode:
 }
 EXPORT_SYMBOL(__mark_inode_dirty);
 
+/*
+ * Do we want to get the inode for writeback?
+ */
+static int get_inode_for_writeback(struct inode *inode)
+{
+	struct address_space *mapping = inode->i_mapping;
+
+	/*
+	 * It's a data integrity sync, but we don't care about
+	 * racing with new pages - we're about data integrity
+	 * of things in the past, not the future
+	 */
+	if (!ACCESS_ONCE(mapping->nrpages))
+		return 0;
+
+	/* Similar logic wrt the I_NEW bit */
+	if (ACCESS_ONCE(inode->i_state) & I_NEW)
+		return 0;
+
+	/*
+	 * When the inode count goes down to zero, the
+	 * I_WILL_FREE and I_FREEING bits might get set.
+	 * But not before.
+	 *
+	 * So if we get this, we know those bits are
+	 * clear, and the inode is still interesting.
+	 */
+	if (atomic_inc_not_zero(&inode->i_count))
+		return 1;
+
+	/*
+	 * Slow path never happens normally, since any
+	 * active inode will be referenced by a dentry
+	 * and thus caught above
+	 */
+	spin_lock(&inode->i_lock);
+	if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
+	    (mapping->nrpages == 0)) {
+		spin_unlock(&inode->i_lock);
+		return 0;
+	}
+	__iget(inode);
+	spin_unlock(&inode->i_lock);
+	return 1;
+}
+
 static void wait_sb_inodes(struct super_block *sb)
 {
 	struct inode *inode, *old_inode = NULL;
@@ -1226,16 +1272,8 @@ static void wait_sb_inodes(struct super_block *sb)
 	 * we still have to wait for that writeout.
 	 */
 	list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
-		struct address_space *mapping = inode->i_mapping;
-
-		spin_lock(&inode->i_lock);
-		if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
-		    (mapping->nrpages == 0)) {
-			spin_unlock(&inode->i_lock);
+		if (!get_inode_for_writeback(inode))
 			continue;
-		}
-		__iget(inode);
-		spin_unlock(&inode->i_lock);
 		spin_unlock(&inode_sb_list_lock);
 
 		/*
@@ -1249,7 +1287,7 @@ static void wait_sb_inodes(struct super_block *sb)
 		iput(old_inode);
 		old_inode = inode;
 
-		filemap_fdatawait(mapping);
+		filemap_fdatawait(inode->i_mapping);
 
 		cond_resched();