xfs: add xfs_verifier_error()

We want to distinguish between corruption, CRC errors,
etc.  In addition, the full stack trace on verifier errors
seems less than helpful; it looks more like an oops than
corruption.

Create a new function to specifically alert the user to
verifier errors, which can differentiate between
EFSCORRUPTED and CRC mismatches.  It doesn't dump stack
unless the xfs error level is turned up high.

Define a new error message (EFSBADCRC) to clearly identify
CRC errors.  (Defined to EBADMSG, bad message)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_linux.h b/fs/xfs/xfs_linux.h
index e8fed74..825249d 100644
--- a/fs/xfs/xfs_linux.h
+++ b/fs/xfs/xfs_linux.h
@@ -179,6 +179,7 @@
 #define ENOATTR		ENODATA		/* Attribute not found */
 #define EWRONGFS	EINVAL		/* Mount with wrong filesystem type */
 #define EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
+#define EFSBADCRC	EBADMSG		/* Bad CRC detected */
 
 #define SYNCHRONIZE()	barrier()
 #define __return_address __builtin_return_address(0)