Btrfs: add hole punching

This patch adds hole punching via fallocate.  Thanks,

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

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index df2f17b0ac5..ee51b7afe97 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4132,6 +4132,8 @@ struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
 void btrfs_free_block_rsv(struct btrfs_root *root,
                           struct btrfs_block_rsv *rsv)
 {
+        if (!rsv)
+                return;
         btrfs_block_rsv_release(root, rsv, (u64)-1);
         kfree(rsv);
 }