diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index ed11d38..f4190f2 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -944,50 +944,18 @@
 static int scrub_submit(struct scrub_dev *sdev)
 {
 	struct scrub_bio *sbio;
-	struct bio *bio;
-	int i;
 
 	if (sdev->curr == -1)
 		return 0;
 
 	sbio = sdev->bios[sdev->curr];
-
-	bio = bio_alloc(GFP_NOFS, sbio->count);
-	if (!bio)
-		goto nomem;
-
-	bio->bi_private = sbio;
-	bio->bi_end_io = scrub_bio_end_io;
-	bio->bi_bdev = sdev->dev->bdev;
-	bio->bi_sector = sbio->physical >> 9;
-
-	for (i = 0; i < sbio->count; ++i) {
-		struct page *page;
-		int ret;
-
-		page = alloc_page(GFP_NOFS);
-		if (!page)
-			goto nomem;
-
-		ret = bio_add_page(bio, page, PAGE_SIZE, 0);
-		if (!ret) {
-			__free_page(page);
-			goto nomem;
-		}
-	}
-
 	sbio->err = 0;
 	sdev->curr = -1;
 	atomic_inc(&sdev->in_flight);
 
-	submit_bio(READ, bio);
+	submit_bio(READ, sbio->bio);
 
 	return 0;
-
-nomem:
-	scrub_free_bio(bio);
-
-	return -ENOMEM;
 }
 
 static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
@@ -995,6 +963,8 @@
 		      u8 *csum, int force)
 {
 	struct scrub_bio *sbio;
+	struct page *page;
+	int ret;
 
 again:
 	/*
@@ -1015,12 +985,22 @@
 	}
 	sbio = sdev->bios[sdev->curr];
 	if (sbio->count == 0) {
+		struct bio *bio;
+
 		sbio->physical = physical;
 		sbio->logical = logical;
+		bio = bio_alloc(GFP_NOFS, SCRUB_PAGES_PER_BIO);
+		if (!bio)
+			return -ENOMEM;
+
+		bio->bi_private = sbio;
+		bio->bi_end_io = scrub_bio_end_io;
+		bio->bi_bdev = sdev->dev->bdev;
+		bio->bi_sector = sbio->physical >> 9;
+		sbio->err = 0;
+		sbio->bio = bio;
 	} else if (sbio->physical + sbio->count * PAGE_SIZE != physical ||
 		   sbio->logical + sbio->count * PAGE_SIZE != logical) {
-		int ret;
-
 		ret = scrub_submit(sdev);
 		if (ret)
 			return ret;
@@ -1030,6 +1010,20 @@
 	sbio->spag[sbio->count].generation = gen;
 	sbio->spag[sbio->count].have_csum = 0;
 	sbio->spag[sbio->count].mirror_num = mirror_num;
+
+	page = alloc_page(GFP_NOFS);
+	if (!page)
+		return -ENOMEM;
+
+	ret = bio_add_page(sbio->bio, page, PAGE_SIZE, 0);
+	if (!ret) {
+		__free_page(page);
+		ret = scrub_submit(sdev);
+		if (ret)
+			return ret;
+		goto again;
+	}
+
 	if (csum) {
 		sbio->spag[sbio->count].have_csum = 1;
 		memcpy(sbio->spag[sbio->count].csum, csum, sdev->csum_size);