+static struct block_device *hib_resume_bdev;
+
+struct hib_bio_batch {
+ atomic_t count;
+ wait_queue_head_t wait;
+ int error;
+};
+
+static void hib_init_batch(struct hib_bio_batch *hb)
+{
+ atomic_set(&hb->count, 0);
+ init_waitqueue_head(&hb->wait);
+ hb->error = 0;
+}
+
+static void hib_end_io(struct bio *bio)
+{
+ struct hib_bio_batch *hb = bio->bi_private;
+ struct page *page = bio->bi_io_vec[0].bv_page;
+
+ if (bio->bi_error) {
+ printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
+ imajor(bio->bi_bdev->bd_inode),
+ iminor(bio->bi_bdev->bd_inode),
+ (unsigned long long)bio->bi_iter.bi_sector);
+ }
+
+ if (bio_data_dir(bio) == WRITE)
+ put_page(page);
+
+ if (bio->bi_error && !hb->error)
+ hb->error = bio->bi_error;
+ if (atomic_dec_and_test(&hb->count))
+ wake_up(&hb->wait);
+
+ bio_put(bio);
+}
+
+static int hib_submit_io(int rw, pgoff_t page_off, void *addr,
+ struct hib_bio_batch *hb)
+{
+ struct page *page = virt_to_page(addr);
+ struct bio *bio;
+ int error = 0;
+
+ bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
+ bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
+ bio->bi_bdev = hib_resume_bdev;
+
+ if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+ printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
+ (unsigned long long)bio->bi_iter.bi_sector);
+ bio_put(bio);
+ return -EFAULT;
+ }
+
+ if (hb) {
+ bio->bi_end_io = hib_end_io;
+ bio->bi_private = hb;
+ atomic_inc(&hb->count);
+ submit_bio(rw, bio);
+ } else {
+ error = submit_bio_wait(rw, bio);
+ bio_put(bio);
+ }
+
+ return error;
+}
+
+static int hib_wait_io(struct hib_bio_batch *hb)
+{
+ wait_event(hb->wait, atomic_read(&hb->count) == 0);
+ return hb->error;
+}