Btrfs: don't null pointer deref on abort

I'm sorry, theres no excuse for this sort of work.  We need to use
root->leafsize since eb may be NULL.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 72b17276c255..e8b29da30154 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3808,7 +3808,7 @@ static int btrfs_destroy_marked_extents(struct btrfs_root *root,
                 while (start <= end) {
                         eb = btrfs_find_tree_block(root, start,
                                                    root->leafsize);
-                        start += eb->len;
+                        start += root->leafsize;
                         if (!eb)
                                 continue;
                         wait_on_extent_buffer_writeback(eb);