From 26f095bf374efc9e9df1bc757b8aade25e47609a Mon Sep 17 00:00:00 2001
From: Chris Mason <chris.mason@oracle.com>
Date: Mon, 20 Feb 2012 22:14:55 -0500
Subject: [PATCH] --- yaml --- r: 287901 b: refs/heads/master c:
 16780cabb877dbd0c8c5e9ff9bdebd6c5bdd1a7b h: refs/heads/master i:   287899:
 7e9388bbc2e7c65a4f684e54c184e271796ea128 v: v3

---
 [refs]                 | 2 +-
 trunk/fs/btrfs/ioctl.c | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index e65d1163a087..b275b63a071c 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a6b0d5c8dbfd428717fc4db4c36757783f391c7b
+refs/heads/master: 16780cabb877dbd0c8c5e9ff9bdebd6c5bdd1a7b
diff --git a/trunk/fs/btrfs/ioctl.c b/trunk/fs/btrfs/ioctl.c
index e9bdb8b783e5..05446f77f99b 100644
--- a/trunk/fs/btrfs/ioctl.c
+++ b/trunk/fs/btrfs/ioctl.c
@@ -1333,6 +1333,12 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
 		goto out;
 	}
 
+	if (name[0] == '.' &&
+	   (namelen == 1 || (name[1] == '.' && namelen == 2))) {
+		ret = -EEXIST;
+		goto out;
+	}
+
 	if (subvol) {
 		ret = btrfs_mksubvol(&file->f_path, name, namelen,
 				     NULL, transid, readonly);