xfs: attribute scrub should use seen_enough to pass error values

When we're iterating all the attributes using the built-in xattr
iterator, we can use the seen_enough variable to pass error codes back
to the main scrub function instead of flattening them into 0/1.  This
will be used in a more exciting fashion in upcoming patches.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/libxfs/xfs_attr.h

@@ -112,7 +112,13 @@ typedef struct xfs_attr_list_context {
 	struct xfs_inode		*dp;		/* inode */
 	struct attrlist_cursor_kern	*cursor;	/* position in list */
 	char				*alist;		/* output buffer */
-	int				seen_enough;	/* T/F: seen enough of list? */
+
+	/*
+	 * Abort attribute list iteration if non-zero.  Can be used to pass
+	 * error values to the xfs_attr_list caller.
+	 */
+	int				seen_enough;
+
 	ssize_t				count;		/* num used entries */
 	int				dupcnt;		/* count dup hashvals seen */
 	int				bufsize;	/* total buffer size */

fs/xfs/scrub/attr.c

@@ -73,7 +73,7 @@ xchk_xattr_listent(
 	sx = container_of(context, struct xchk_xattr, context);
 
 	if (xchk_should_terminate(sx->sc, &error)) {
-		context->seen_enough = 1;
+		context->seen_enough = error;
 		return;
 	}
 
@@ -115,7 +115,7 @@ xchk_xattr_listent(
 					     args.blkno);
 fail_xref:
 	if (sx->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
-		context->seen_enough = 1;
+		context->seen_enough = XFS_ITER_ABORT;
 	return;
 }
 
@@ -454,6 +454,10 @@ xchk_xattr(
 	error = xfs_attr_list_int_ilocked(&sx.context);
 	if (!xchk_fblock_process_error(sc, XFS_ATTR_FORK, 0, &error))
 		goto out;
+
+	/* Did our listent function try to return any errors? */
+	if (sx.context.seen_enough < 0)
+		error = sx.context.seen_enough;
 out:
 	return error;
 }