if (!first_sector->dev->bdev)
                goto out;
 
-       bio = btrfs_bio_alloc(BIO_MAX_VECS);
-       bio_set_dev(bio, first_sector->dev->bdev);
+       bio = bio_alloc(first_sector->dev->bdev, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
 
        for (i = 0; i < sblock->sector_count; i++) {
                struct scrub_sector *sector = sblock->sectors[i];
        }
        sbio = sctx->wr_curr_bio;
        if (sbio->sector_count == 0) {
-               struct bio *bio;
-
                ret = fill_writer_pointer_gap(sctx, sector->physical_for_dev_replace);
                if (ret) {
                        mutex_unlock(&sctx->wr_lock);
                sbio->physical = sector->physical_for_dev_replace;
                sbio->logical = sector->logical;
                sbio->dev = sctx->wr_tgtdev;
-               bio = sbio->bio;
-               if (!bio) {
-                       bio = btrfs_bio_alloc(sctx->sectors_per_bio);
-                       sbio->bio = bio;
+               if (!sbio->bio) {
+                       sbio->bio = bio_alloc(sbio->dev->bdev, sctx->sectors_per_bio,
+                                             REQ_OP_WRITE, GFP_NOFS);
                }
-
-               bio->bi_private = sbio;
-               bio->bi_end_io = scrub_wr_bio_end_io;
-               bio_set_dev(bio, sbio->dev->bdev);
-               bio->bi_iter.bi_sector = sbio->physical >> 9;
-               bio->bi_opf = REQ_OP_WRITE;
+               sbio->bio->bi_private = sbio;
+               sbio->bio->bi_end_io = scrub_wr_bio_end_io;
+               sbio->bio->bi_iter.bi_sector = sbio->physical >> 9;
                sbio->status = 0;
        } else if (sbio->physical + sbio->sector_count * sectorsize !=
                   sector->physical_for_dev_replace ||
 
        sbio = sctx->wr_curr_bio;
        sctx->wr_curr_bio = NULL;
-       WARN_ON(!sbio->bio->bi_bdev);
        scrub_pending_bio_inc(sctx);
        /* process all writes in a single worker thread. Then the block layer
         * orders the requests before sending them to the driver which
        }
        sbio = sctx->bios[sctx->curr];
        if (sbio->sector_count == 0) {
-               struct bio *bio;
-
                sbio->physical = sector->physical;
                sbio->logical = sector->logical;
                sbio->dev = sector->dev;
-               bio = sbio->bio;
-               if (!bio) {
-                       bio = btrfs_bio_alloc(sctx->sectors_per_bio);
-                       sbio->bio = bio;
+               if (!sbio->bio) {
+                       sbio->bio = bio_alloc(sbio->dev->bdev, sctx->sectors_per_bio,
+                                             REQ_OP_READ, GFP_NOFS);
                }
-
-               bio->bi_private = sbio;
-               bio->bi_end_io = scrub_bio_end_io;
-               bio_set_dev(bio, sbio->dev->bdev);
-               bio->bi_iter.bi_sector = sbio->physical >> 9;
-               bio->bi_opf = REQ_OP_READ;
+               sbio->bio->bi_private = sbio;
+               sbio->bio->bi_end_io = scrub_bio_end_io;
+               sbio->bio->bi_iter.bi_sector = sbio->physical >> 9;
                sbio->status = 0;
        } else if (sbio->physical + sbio->sector_count * sectorsize !=
                   sector->physical ||
                goto bioc_out;
        }
 
-       bio = btrfs_bio_alloc(BIO_MAX_VECS);
+       bio = bio_alloc(NULL, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
        bio->bi_iter.bi_sector = logical >> 9;
        bio->bi_private = sblock;
        bio->bi_end_io = scrub_missing_raid56_end_io;
        if (ret || !bioc || !bioc->raid_map)
                goto bioc_out;
 
-       bio = btrfs_bio_alloc(BIO_MAX_VECS);
+       bio = bio_alloc(NULL, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
        bio->bi_iter.bi_sector = sparity->logic_start >> 9;
        bio->bi_private = sparity;
        bio->bi_end_io = scrub_parity_bio_endio;