xfs: add CRC checks for quota blocks

Use the reserved space in struct xfs_dqblk to store a UUID and a crc
for the quota blocks.

[dchinner@redhat.com] Add a LSN field and update for current verifier
infrastructure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 6778a79..27b3ec2 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -1979,6 +1979,16 @@
 		}
 		bp->b_ops = &xfs_agi_buf_ops;
 		break;
+	case XFS_BLF_UDQUOT_BUF:
+	case XFS_BLF_PDQUOT_BUF:
+	case XFS_BLF_GDQUOT_BUF:
+		if (*(__be16 *)bp->b_addr != cpu_to_be16(XFS_DQUOT_MAGIC)) {
+			xfs_warn(mp, "Bad DQUOT block magic!");
+			ASSERT(0);
+			break;
+		}
+		bp->b_ops = &xfs_dquot_buf_ops;
+		break;
 	default:
 		break;
 	}