Btrfs: confirmation of value is added before trace_btrfs_get_extent() is called

We should confirm the value of extent_map before calling
trace_btrfs_get_extent() because the value of extent_map has the
possibility of NULL.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d24b65014612509d45937478d914b2e22cc3d243..f92def2467a61c6f2062408a6dba76f9f1b30ce7 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5505,7 +5505,8 @@ insert:
        write_unlock(&em_tree->lock);
 out:
 
-       trace_btrfs_get_extent(root, em);
+       if (em)
+               trace_btrfs_get_extent(root, em);
 
        if (path)
                btrfs_free_path(path);