blk-crypto: convert to use bio_submit_split_bioset()

Unify bio split code, prepare to fix ordering of split IO.

Signed-off-by: Yu Kuai <[e-mail]>
Reviewed-by: Bart Van Assche <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

block/blk-crypto-fallback.c

···
 #include <linux/module.h>
 #include <linux/random.h>
 #include <linux/scatterlist.h>
-#include <trace/events/block.h>
 
 #include "blk-cgroup.h"
 #include "blk-crypto-internal.h"
···
 		if (++i == BIO_MAX_VECS)
 			break;
 	}
+
 	if (num_sectors < bio_sectors(bio)) {
-		struct bio *split_bio;
-
-		split_bio = bio_split(bio, num_sectors, GFP_NOIO,
-				      &crypto_bio_split);
-		if (IS_ERR(split_bio)) {
-			bio->bi_status = BLK_STS_RESOURCE;
+		bio = bio_submit_split_bioset(bio, num_sectors,
+					      &crypto_bio_split);
+		if (!bio)
 			return false;
-		}
 
-		bio_chain(split_bio, bio);
-		trace_block_split(split_bio, bio->bi_iter.bi_sector);
-		submit_bio_noacct(bio);
-		*bio_ptr = split_bio;
+		*bio_ptr = bio;
 	}
 
 	return true;