--- zzzz-none-000/linux-3.10.107/fs/logfs/dev_bdev.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/logfs/dev_bdev.c	2021-02-04 17:41:59.000000000 +0000
@@ -14,16 +14,10 @@
 
 #define PAGE_OFS(ofs) ((ofs) & (PAGE_SIZE-1))
 
-static void request_complete(struct bio *bio, int err)
-{
-	complete((struct completion *)bio->bi_private);
-}
-
 static int sync_request(struct page *page, struct block_device *bdev, int rw)
 {
 	struct bio bio;
 	struct bio_vec bio_vec;
-	struct completion complete;
 
 	bio_init(&bio);
 	bio.bi_max_vecs = 1;
@@ -32,16 +26,11 @@
 	bio_vec.bv_len = PAGE_SIZE;
 	bio_vec.bv_offset = 0;
 	bio.bi_vcnt = 1;
-	bio.bi_size = PAGE_SIZE;
 	bio.bi_bdev = bdev;
-	bio.bi_sector = page->index * (PAGE_SIZE >> 9);
-	init_completion(&complete);
-	bio.bi_private = &complete;
-	bio.bi_end_io = request_complete;
-
-	submit_bio(rw, &bio);
-	wait_for_completion(&complete);
-	return test_bit(BIO_UPTODATE, &bio.bi_flags) ? 0 : -EIO;
+	bio.bi_iter.bi_sector = page->index * (PAGE_SIZE >> 9);
+	bio.bi_iter.bi_size = PAGE_SIZE;
+
+	return submit_bio_wait(rw, &bio);
 }
 
 static int bdev_readpage(void *_sb, struct page *page)
@@ -64,25 +53,19 @@
 
 static DECLARE_WAIT_QUEUE_HEAD(wq);
 
-static void writeseg_end_io(struct bio *bio, int err)
+static void writeseg_end_io(struct bio *bio)
 {
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bvec;
+	int i;
 	struct super_block *sb = bio->bi_private;
 	struct logfs_super *super = logfs_super(sb);
-	struct page *page;
 
-	BUG_ON(!uptodate); /* FIXME: Retry io or write elsewhere */
-	BUG_ON(err);
-	BUG_ON(bio->bi_vcnt == 0);
-	do {
-		page = bvec->bv_page;
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
-
-		end_page_writeback(page);
-		page_cache_release(page);
-	} while (bvec >= bio->bi_io_vec);
+	BUG_ON(bio->bi_error); /* FIXME: Retry io or write elsewhere */
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		end_page_writeback(bvec->bv_page);
+		page_cache_release(bvec->bv_page);
+	}
 	bio_put(bio);
 	if (atomic_dec_and_test(&super->s_pending_writes))
 		wake_up(&wq);
@@ -98,7 +81,7 @@
 	unsigned int max_pages;
 	int i;
 
-	max_pages = min(nr_pages, (size_t) bio_get_nr_vecs(super->s_bdev));
+	max_pages = min_t(size_t, nr_pages, BIO_MAX_PAGES);
 
 	bio = bio_alloc(GFP_NOFS, max_pages);
 	BUG_ON(!bio);
@@ -107,9 +90,9 @@
 		if (i >= max_pages) {
 			/* Block layer cannot split bios :( */
 			bio->bi_vcnt = i;
-			bio->bi_size = i * PAGE_SIZE;
+			bio->bi_iter.bi_size = i * PAGE_SIZE;
 			bio->bi_bdev = super->s_bdev;
-			bio->bi_sector = ofs >> 9;
+			bio->bi_iter.bi_sector = ofs >> 9;
 			bio->bi_private = sb;
 			bio->bi_end_io = writeseg_end_io;
 			atomic_inc(&super->s_pending_writes);
@@ -134,9 +117,9 @@
 		unlock_page(page);
 	}
 	bio->bi_vcnt = nr_pages;
-	bio->bi_size = nr_pages * PAGE_SIZE;
+	bio->bi_iter.bi_size = nr_pages * PAGE_SIZE;
 	bio->bi_bdev = super->s_bdev;
-	bio->bi_sector = ofs >> 9;
+	bio->bi_iter.bi_sector = ofs >> 9;
 	bio->bi_private = sb;
 	bio->bi_end_io = writeseg_end_io;
 	atomic_inc(&super->s_pending_writes);
@@ -168,14 +151,12 @@
 }
 
 
-static void erase_end_io(struct bio *bio, int err) 
+static void erase_end_io(struct bio *bio)
 { 
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 
 	struct super_block *sb = bio->bi_private; 
 	struct logfs_super *super = logfs_super(sb); 
 
-	BUG_ON(!uptodate); /* FIXME: Retry io or write elsewhere */ 
-	BUG_ON(err); 
+	BUG_ON(bio->bi_error); /* FIXME: Retry io or write elsewhere */ 
 	BUG_ON(bio->bi_vcnt == 0); 
 	bio_put(bio); 
 	if (atomic_dec_and_test(&super->s_pending_writes))
@@ -190,7 +171,7 @@
 	unsigned int max_pages;
 	int i;
 
-	max_pages = min(nr_pages, (size_t) bio_get_nr_vecs(super->s_bdev));
+	max_pages = min_t(size_t, nr_pages, BIO_MAX_PAGES);
 
 	bio = bio_alloc(GFP_NOFS, max_pages);
 	BUG_ON(!bio);
@@ -199,9 +180,9 @@
 		if (i >= max_pages) {
 			/* Block layer cannot split bios :( */
 			bio->bi_vcnt = i;
-			bio->bi_size = i * PAGE_SIZE;
+			bio->bi_iter.bi_size = i * PAGE_SIZE;
 			bio->bi_bdev = super->s_bdev;
-			bio->bi_sector = ofs >> 9;
+			bio->bi_iter.bi_sector = ofs >> 9;
 			bio->bi_private = sb;
 			bio->bi_end_io = erase_end_io;
 			atomic_inc(&super->s_pending_writes);
@@ -220,9 +201,9 @@
 		bio->bi_io_vec[i].bv_offset = 0;
 	}
 	bio->bi_vcnt = nr_pages;
-	bio->bi_size = nr_pages * PAGE_SIZE;
+	bio->bi_iter.bi_size = nr_pages * PAGE_SIZE;
 	bio->bi_bdev = super->s_bdev;
-	bio->bi_sector = ofs >> 9;
+	bio->bi_iter.bi_sector = ofs >> 9;
 	bio->bi_private = sb;
 	bio->bi_end_io = erase_end_io;
 	atomic_inc(&super->s_pending_writes);