From 4a3c299b9db8d6eefb7e70969a0af7481ab18473 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Tue, 16 Aug 2011 15:31:30 +0100
Subject: [PATCH] --- yaml --- r: 275751 b: refs/heads/master c:
 dd179946db2493646955efc112d73c85b3cafcb1 h: refs/heads/master i:   275749:
 ab68c0b0b4863239416235263bf055e666962927   275747:
 17a3a76195922e83add326928c8c41c4d588a637   275743:
 b51c380a229423b9e6769e2b843d826cc2d94eaa v: v3

---
 [refs]            |  2 +-
 trunk/fs/dcache.c | 11 ++++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index a71a28cb1684..82b2057e066e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f1fd306a91f875e65af0e04855b23adda6831ac9
+refs/heads/master: dd179946db2493646955efc112d73c85b3cafcb1
diff --git a/trunk/fs/dcache.c b/trunk/fs/dcache.c
index a901c6901bce..10ba92def3f6 100644
--- a/trunk/fs/dcache.c
+++ b/trunk/fs/dcache.c
@@ -36,6 +36,7 @@
 #include <linux/bit_spinlock.h>
 #include <linux/rculist_bl.h>
 #include <linux/prefetch.h>
+#include <linux/ratelimit.h>
 #include "internal.h"
 
 /*
@@ -2383,8 +2384,16 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
 				actual = __d_unalias(inode, dentry, alias);
 			}
 			write_sequnlock(&rename_lock);
-			if (IS_ERR(actual))
+			if (IS_ERR(actual)) {
+				if (PTR_ERR(actual) == -ELOOP)
+					pr_warn_ratelimited(
+						"VFS: Lookup of '%s' in %s %s"
+						" would have caused loop\n",
+						dentry->d_name.name,
+						inode->i_sb->s_type->name,
+						inode->i_sb->s_id);
 				dput(alias);
+			}
 			goto out_nolock;
 		}
 	}