On Wed, Apr 17, 2024 at 02:47:14PM +0200, Stefan Haberland wrote: > set_blocksize() does basically also set i_blkbits like it was before. > The dasd_format ioctl does only work on a disabled device. To achieve this > all partitions need to be unmounted. > The tooling also refuses to work on disks actually in use. > > So there should be no page cache to evict. You mean this? if (base->state != DASD_STATE_BASIC) { pr_warn("%s: The DASD cannot be formatted while it is enabled\n", dev_name(&base->cdev->dev)); return -EBUSY; } OK, but what would prevent dasd_ioctl_disable() from working while disk is in use? And I don't see anything that would evict the page cache in dasd_ioctl_disable() either, actually... What am I missing here?