Add a workaround.

Now, if we have for example: ad0s1 ad0s1c ad2s1 ad2s1c and we will try
to do: gconcat label foo /dev/ad0s1 /dev/ad2s1 we'll get a panic:
panic: spoiled but dcr = 1
for inside of geom_slice class, backtrace shows:
g_access()
g_slice_access()
g_access()
g_concat_read_metadata()
We need to get a proper fix for this race before geom(8) will be committed.

1 files changed, 2 insertions, 2 deletions

diff --git a/sbin/gconcat/gconcat.c b/sbin/gconcat/gconcat.c
index c8a5ca7..7219078 100644
--- a/sbin/gconcat/gconcat.c
+++ b/sbin/gconcat/gconcat.c
@@ -238,8 +238,6 @@ concat_label(int argc, char *argv[])
 	if (argc < 2)
 		usage();
 
-	load_module();
-
 	strlcpy(md.md_magic, G_CONCAT_MAGIC, sizeof(md.md_magic));
 	md.md_version = G_CONCAT_VERSION;
 	strlcpy(md.md_name, argv[0], sizeof(md.md_name));
@@ -294,6 +292,8 @@ concat_label(int argc, char *argv[])
 			printf("Metadata value stored on %s.\n", argv[i]); 
 	}
 
+	load_module();
+
 	exit(status);
 }