diff --git a/drivers/staging/erofs/decompressor.c b/drivers/staging/erofs/decompressor.c
index 80f1f39719ba..1fb0abb98dff 100644
--- a/drivers/staging/erofs/decompressor.c
+++ b/drivers/staging/erofs/decompressor.c
@@ -13,7 +13,7 @@
 #define LZ4_DISTANCE_MAX 65535	/* set to maximum value by default */
 #endif
 
-#define LZ4_MAX_DISTANCE_PAGES	DIV_ROUND_UP(LZ4_DISTANCE_MAX, PAGE_SIZE)
+#define LZ4_MAX_DISTANCE_PAGES	(DIV_ROUND_UP(LZ4_DISTANCE_MAX, PAGE_SIZE) + 1)
 #ifndef LZ4_DECOMPRESS_INPLACE_MARGIN
 #define LZ4_DECOMPRESS_INPLACE_MARGIN(srcsize)  (((srcsize) >> 8) + 32)
 #endif
@@ -35,19 +35,28 @@ static int lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
 	const unsigned int nr =
 		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
 	struct page *availables[LZ4_MAX_DISTANCE_PAGES] = { NULL };
-	unsigned long unused[DIV_ROUND_UP(LZ4_MAX_DISTANCE_PAGES,
-					  BITS_PER_LONG)] = { 0 };
+	unsigned long bounced[DIV_ROUND_UP(LZ4_MAX_DISTANCE_PAGES,
+					   BITS_PER_LONG)] = { 0 };
 	void *kaddr = NULL;
-	unsigned int i, j, k;
+	unsigned int i, j, top;
 
-	for (i = 0; i < nr; ++i) {
+	top = 0;
+	for (i = j = 0; i < nr; ++i, ++j) {
 		struct page *const page = rq->out[i];
+		struct page *victim;
 
-		j = i & (LZ4_MAX_DISTANCE_PAGES - 1);
-		if (availables[j])
-			__set_bit(j, unused);
+		if (j >= LZ4_MAX_DISTANCE_PAGES)
+			j = 0;
+
+		/* 'valid' bounced can only be tested after a complete round */
+		if (test_bit(j, bounced)) {
+			DBG_BUGON(i < LZ4_MAX_DISTANCE_PAGES);
+			DBG_BUGON(top >= LZ4_MAX_DISTANCE_PAGES);
+			availables[top++] = rq->out[i - LZ4_MAX_DISTANCE_PAGES];
+		}
 
 		if (page) {
+			__clear_bit(j, bounced);
 			if (kaddr) {
 				if (kaddr + PAGE_SIZE == page_address(page))
 					kaddr += PAGE_SIZE;
@@ -59,27 +68,24 @@ static int lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
 			continue;
 		}
 		kaddr = NULL;
+		__set_bit(j, bounced);
 
-		k = find_first_bit(unused, LZ4_MAX_DISTANCE_PAGES);
-		if (k < LZ4_MAX_DISTANCE_PAGES) {
-			j = k;
-			get_page(availables[j]);
+		if (top) {
+			victim = availables[--top];
+			get_page(victim);
 		} else {
-			DBG_BUGON(availables[j]);
-
 			if (!list_empty(pagepool)) {
-				availables[j] = lru_to_page(pagepool);
-				list_del(&availables[j]->lru);
-				DBG_BUGON(page_ref_count(availables[j]) != 1);
+				victim = lru_to_page(pagepool);
+				list_del(&victim->lru);
+				DBG_BUGON(page_ref_count(victim) != 1);
 			} else {
-				availables[j] = alloc_pages(GFP_KERNEL, 0);
-				if (!availables[j])
+				victim = alloc_pages(GFP_KERNEL, 0);
+				if (!victim)
 					return -ENOMEM;
 			}
-			availables[j]->mapping = Z_EROFS_MAPPING_STAGING;
+			victim->mapping = Z_EROFS_MAPPING_STAGING;
 		}
-		rq->out[i] = availables[j];
-		__clear_bit(j, unused);
+		rq->out[i] = victim;
 	}
 	return kaddr ? 1 : 0;
 }