[PATCH] dm snapshot: fix freeing pending exception

Fix oops when removing full snapshot
kernel bugzilla bug 7040

If a snapshot became invalid (full) while there is outstanding
pending_exception, pending_complete() forgets to remove
the corresponding exception from its exception table before freeing it.

Already fixed in 2.6.19.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

drivers/md/dm-snap.c

@@ -691,6 +691,7 @@ static void pending_complete(struct pending_exception *pe, int success)
 
 		free_exception(e);
 
+		remove_exception(&pe->e);
 		error_snapshot_bios(pe);
 		goto out;
 	}