ocfs2: block read meta ecc.

Add block check calls to the read_block validate functions.  This is the
almost all of the read-side checking of metaecc.  xattr buckets are not checked
yet.   Writes are also unchecked, and so a read-write mount will quickly fail.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index dfc51c3..bc822d6 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -42,6 +42,7 @@
 
 #include "ocfs2.h"
 #include "alloc.h"
+#include "blockcheck.h"
 #include "dlmglue.h"
 #include "file.h"
 #include "symlink.h"
@@ -322,12 +323,28 @@
 static int ocfs2_validate_xattr_block(struct super_block *sb,
 				      struct buffer_head *bh)
 {
+	int rc;
 	struct ocfs2_xattr_block *xb =
 		(struct ocfs2_xattr_block *)bh->b_data;
 
 	mlog(0, "Validating xattr block %llu\n",
 	     (unsigned long long)bh->b_blocknr);
 
+	BUG_ON(!buffer_uptodate(bh));
+
+	/*
+	 * If the ecc fails, we return the error but otherwise
+	 * leave the filesystem running.  We know any error is
+	 * local to this block.
+	 */
+	rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &xb->xb_check);
+	if (rc)
+		return rc;
+
+	/*
+	 * Errors after here are fatal
+	 */
+
 	if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {
 		ocfs2_error(sb,
 			    "Extended attribute block #%llu has bad "