Commits
Miao Xie committed 90d2c51dbb4
Btrfs: add NULL check for do_walk_down() btrfs_find_create_tree_block() may return NULL, so we must check the returned value, or we will access a NULL pointer. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>