bdev: fix max_rw_size calculation

max write size calculation need to account aligned length and the
blocklen with metadata as done via bdev_get_max_write. This otherwise
fails during bdev_io_get_buf for bounce buffer where max length
returned by bdev_io_get_max_buf_len breaches the iobuf_large length.

Change-Id: I0e2ee2cfa80f0617f8b1379315b9dba2459d2c71
Signed-off-by: Diwakar Sharma <diwakar.sharma@datacore.com>

Author: dsharma-dc

lib/bdev/bdev.c

@@ -7795,17 +7795,17 @@ bdev_register(struct spdk_bdev *bdev)
 		}
 	}
 
-	spdk_iobuf_get_opts(&iobuf_opts, sizeof(iobuf_opts));
-	if (spdk_bdev_get_buf_align(bdev) > 1) {
-		bdev->max_rw_size = spdk_min(bdev->max_rw_size ? bdev->max_rw_size : UINT32_MAX,
-					     iobuf_opts.large_bufsize / bdev->blocklen);
-	}
-
 	/* If the user didn't specify a write unit size, set it to one. */
 	if (bdev->write_unit_size == 0) {
 		bdev->write_unit_size = 1;
 	}
 
+	spdk_iobuf_get_opts(&iobuf_opts, sizeof(iobuf_opts));
+	if (spdk_bdev_get_buf_align(bdev) > 1) {
+		bdev->max_rw_size = spdk_min(bdev->max_rw_size ? bdev->max_rw_size : UINT32_MAX,
+					     bdev_get_max_write(bdev, iobuf_opts.large_bufsize));
+	}
+
 	/* Set ACWU value to the write unit size if bdev module did not set it (does not support it natively) */
 	if (bdev->acwu == 0) {
 		bdev->acwu = bdev->write_unit_size;