Btrfs: space leak tracepoints

This in addition to a script in my btrfs-tracing tree will help track down space
leaks when we're getting space left over in block groups on umount.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index f8962a9..213ffa8 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -438,6 +438,8 @@
 					  trans->bytes_reserved);
 	if (ret)
 		goto out;
+	trace_btrfs_space_reservation(root->fs_info, "ino_cache", (u64)trans,
+				      trans->bytes_reserved, 1);
 again:
 	inode = lookup_free_ino_inode(root, path);
 	if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
@@ -498,6 +500,8 @@
 out_put:
 	iput(inode);
 out_release:
+	trace_btrfs_space_reservation(root->fs_info, "ino_cache", (u64)trans,
+				      trans->bytes_reserved, 0);
 	btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved);
 out:
 	trans->block_rsv = rsv;