block: don't add or resize partition on the disk with GENHD_FL_NO_PART

Commit a33df75 ("block: use an xarray for disk->part_tbl") remove
disk_expand_part_tbl() in add_partition(), which means all kinds of
devices will support extended dynamic `dev_t`.
However, some devices with GENHD_FL_NO_PART are not expected to add or
resize partition.
Fix this by adding check of GENHD_FL_NO_PART before add or resize
partition.

Fixes: a33df75 ("block: use an xarray for disk->part_tbl")
Signed-off-by: Li Lingfeng <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: Li Lingfeng

block/ioctl.c

@@ -20,6 +20,8 @@ static int blkpg_do_ioctl(struct block_device *bdev,
 	struct blkpg_partition p;
 	long long start, length;
 
+	if (disk->flags & GENHD_FL_NO_PART)
+		return -EINVAL;
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
 	if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))