block: use bvec_kmap_local in bio_integrity_process

Using local kmaps slightly reduces the chances to stray writes, and
the bvec interface cleans up the code a little bit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727055646.118787-16-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/bio-integrity.c

@@ -172,18 +172,16 @@ static blk_status_t bio_integrity_process(struct bio *bio,
 	iter.prot_buf = prot_buf;
 
 	__bio_for_each_segment(bv, bio, bviter, *proc_iter) {
-		void *kaddr = kmap_atomic(bv.bv_page);
+		void *kaddr = bvec_kmap_local(&bv);
 
-		iter.data_buf = kaddr + bv.bv_offset;
+		iter.data_buf = kaddr;
 		iter.data_size = bv.bv_len;
-
 		ret = proc_fn(&iter);
-		if (ret) {
-			kunmap_atomic(kaddr);
-			return ret;
-		}
+		kunmap_local(kaddr);
+
+		if (ret)
+			break;
 
-		kunmap_atomic(kaddr);
 	}
 	return ret;
 }