From 39ce7d6e0c263a8b690d03571c8e553055947eac Mon Sep 17 00:00:00 2001
From: Mark Fasheh <mfasheh@suse.com>
Date: Mon, 29 Aug 2011 14:17:04 -0700
Subject: [PATCH] --- yaml --- r: 297879 b: refs/heads/master c:
 e5df957328b18baa731307c66cfe8e7a4981df65 h: refs/heads/master i:   297877:
 8f2779c767a08c22cc8af47567c20a0d98b4a382   297875:
 2b52378c4dcf4b89b57536f4733018e06b30a3a6   297871:
 41e91d3c456220194d00a6689a42ef8c6428f002 v: v3

---
 [refs]                 | 2 +-
 trunk/fs/btrfs/ctree.c | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index c50eb09c4eab..0d87775be49d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4ed1d16e944c61cfb8a78159548672e7df168d97
+refs/heads/master: e5df957328b18baa731307c66cfe8e7a4981df65
diff --git a/trunk/fs/btrfs/ctree.c b/trunk/fs/btrfs/ctree.c
index e2e43c07f6b1..3b767d2b68e8 100644
--- a/trunk/fs/btrfs/ctree.c
+++ b/trunk/fs/btrfs/ctree.c
@@ -333,7 +333,11 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
 					       buf->len, &refs, &flags);
 		if (ret)
 			return ret;
-		BUG_ON(refs == 0);
+		if (refs == 0) {
+			ret = -EROFS;
+			btrfs_std_error(root->fs_info, ret);
+			return ret;
+		}
 	} else {
 		refs = 1;
 		if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||