diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index b877203f1dc5..4445a52a0707 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1798,6 +1798,9 @@ static int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *
 	 */
 	ASSERT(sctx->cur_stripe < SCRUB_TOTAL_STRIPES);
 
+	/* @found_logical_ret must be specified. */
+	ASSERT(found_logical_ret);
+
 	stripe = &sctx->stripes[sctx->cur_stripe];
 	scrub_reset_stripe(stripe);
 	ret = scrub_find_fill_first_stripe(bg, &sctx->extent_path,
@@ -1806,8 +1809,7 @@ static int queue_scrub_stripe(struct scrub_ctx *sctx, struct btrfs_block_group *
 	/* Either >0 as no more extents or <0 for error. */
 	if (ret)
 		return ret;
-	if (found_logical_ret)
-		*found_logical_ret = stripe->logical;
+	*found_logical_ret = stripe->logical;
 	sctx->cur_stripe++;
 
 	/* We filled one group, submit it. */
@@ -2010,7 +2012,7 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx,
 
 	/* Go through each extent items inside the logical range */
 	while (cur_logical < logical_end) {
-		u64 found_logical;
+		u64 found_logical = U64_MAX;
 		u64 cur_physical = physical + cur_logical - logical_start;
 
 		/* Canceled? */
@@ -2045,6 +2047,8 @@ static int scrub_simple_mirror(struct scrub_ctx *sctx,
 		if (ret < 0)
 			break;
 
+		/* queue_scrub_stripe() returned 0, @found_logical must be updated. */
+		ASSERT(found_logical != U64_MAX);
 		cur_logical = found_logical + BTRFS_STRIPE_LEN;
 
 		/* Don't hold CPU for too long time */