dm crypt: introduce crypt_write_io_loop

Introduce crypt_write_io_loop().
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

drivers/md/dm-crypt.c

@@ -595,17 +595,13 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int error)
 	io->sector += bio_sectors(clone);
 }
 
-static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
+static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io)
 {
 	struct crypt_config *cc = io->target->private;
 	struct bio *clone;
 	unsigned remaining = io->base_bio->bi_size;
 	int r;
 
-	atomic_inc(&io->pending);
-
-	crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
-
 	/*
 	 * The allocated buffers can be smaller than the whole bio,
 	 * so repeat the whole process until all the data can be handled.
@@ -645,6 +641,16 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 	}
 }
 
+static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
+{
+	struct crypt_config *cc = io->target->private;
+
+	atomic_inc(&io->pending);
+
+	crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
+	kcryptd_crypt_write_convert_loop(io);
+}
+
 static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
 {
 	if (unlikely(error < 0))