raid5: use bio_reset()

Had to shuffle the code around a bit (where bi_rw and bi_end_io were
set), but shouldn't really be anything tricky here
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>

drivers/md/raid5.c

@@ -567,14 +567,6 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 		bi = &sh->dev[i].req;
 		rbi = &sh->dev[i].rreq; /* For writing to replacement */
 
-		bi->bi_rw = rw;
-		rbi->bi_rw = rw;
-		if (rw & WRITE) {
-			bi->bi_end_io = raid5_end_write_request;
-			rbi->bi_end_io = raid5_end_write_request;
-		} else
-			bi->bi_end_io = raid5_end_read_request;
-
 		rcu_read_lock();
 		rrdev = rcu_dereference(conf->disks[i].replacement);
 		smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
@@ -649,7 +641,14 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 
 			set_bit(STRIPE_IO_STARTED, &sh->state);
 
+			bio_reset(bi);
 			bi->bi_bdev = rdev->bdev;
+			bi->bi_rw = rw;
+			bi->bi_end_io = (rw & WRITE)
+				? raid5_end_write_request
+				: raid5_end_read_request;
+			bi->bi_private = sh;
+
 			pr_debug("%s: for %llu schedule op %ld on disc %d\n",
 				__func__, (unsigned long long)sh->sector,
 				bi->bi_rw, i);
@@ -663,12 +662,9 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 			if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
 				bi->bi_rw |= REQ_FLUSH;
 
-			bi->bi_flags = 1 << BIO_UPTODATE;
-			bi->bi_idx = 0;
 			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			bi->bi_io_vec[0].bv_offset = 0;
 			bi->bi_size = STRIPE_SIZE;
-			bi->bi_next = NULL;
 			if (rrdev)
 				set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
 			trace_block_bio_remap(bdev_get_queue(bi->bi_bdev),
@@ -683,7 +679,13 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 
 			set_bit(STRIPE_IO_STARTED, &sh->state);
 
+			bio_reset(rbi);
 			rbi->bi_bdev = rrdev->bdev;
+			rbi->bi_rw = rw;
+			BUG_ON(!(rw & WRITE));
+			rbi->bi_end_io = raid5_end_write_request;
+			rbi->bi_private = sh;
+
 			pr_debug("%s: for %llu schedule op %ld on "
 				 "replacement disc %d\n",
 				__func__, (unsigned long long)sh->sector,
@@ -695,12 +697,9 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 			else
 				rbi->bi_sector = (sh->sector
 						  + rrdev->data_offset);
-			rbi->bi_flags = 1 << BIO_UPTODATE;
-			rbi->bi_idx = 0;
 			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			rbi->bi_io_vec[0].bv_offset = 0;
 			rbi->bi_size = STRIPE_SIZE;
-			rbi->bi_next = NULL;
 			trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
 					      rbi, disk_devt(conf->mddev->gendisk),
 					      sh->dev[i].sector);