fs: clear I_DIRTY_TIME in sync_lazytime

For file systems implementing ->sync_lazytime, I_DIRTY_TIME fails to get
cleared in sync_lazytime, and might cause additional calls to
sync_lazytime during inode deactivation.  Use the same pattern as in
__mark_inode_dirty to clear the flag under the inode lock.

Fixes: 5cf06ea ("fs: add a ->sync_lazytime method")
Signed-off-by: Christoph Hellwig <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

Author: Christoph Hellwig

fs/fs-writeback.c

@@ -1711,16 +1711,28 @@ static void requeue_inode(struct inode *inode, struct bdi_writeback *wb,
 	}
 }
 
+static bool __sync_lazytime(struct inode *inode)
+{
+	spin_lock(&inode->i_lock);
+	if (!(inode_state_read(inode) & I_DIRTY_TIME)) {
+		spin_unlock(&inode->i_lock);
+		return false;
+	}
+	inode_state_clear(inode, I_DIRTY_TIME);
+	spin_unlock(&inode->i_lock);
+	inode->i_op->sync_lazytime(inode);
+	return true;
+}
+
 bool sync_lazytime(struct inode *inode)
 {
 	if (!(inode_state_read_once(inode) & I_DIRTY_TIME))
 		return false;
 
 	trace_writeback_lazytime(inode);
 	if (inode->i_op->sync_lazytime)
-		inode->i_op->sync_lazytime(inode);
-	else
-		mark_inode_dirty_sync(inode);
+		return __sync_lazytime(inode);
+	mark_inode_dirty_sync(inode);
 	return true;
 }