Btrfs: Make sure to cow the root during a snapshot

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7e4cf62ada5a..504d37dfa6c9 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2096,6 +2096,7 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
         struct btrfs_trans_handle *trans;
         struct btrfs_key key;
         struct btrfs_root_item new_root_item;
+        struct buffer_head *tmp;
         int ret;
         int err;
         u64 objectid;
@@ -2123,6 +2124,7 @@ static int create_snapshot(struct btrfs_root *root, char *name, int namelen)
         key.offset = 1;
         key.flags = 0;
         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+        btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
         btrfs_set_root_blocknr(&new_root_item, bh_blocknr(root->node));
 
         ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,