On Fri, May 05, 2023 at 11:51:19AM -0700, Darrick J. Wong wrote: > Fun question: What happens when the swap disk falls off the bus? Your system is toast. > > - if (IS_ERR(blkdev_get_by_dev(bdev->bd_dev, mode | FMODE_EXCL, &bdev))) > > + if (IS_ERR(blkdev_get_by_dev(bdev->bd_dev, mode | FMODE_EXCL, &bdev, > > + NULL))) > > return -EBUSY; > > ret = set_blocksize(bdev, n); > > blkdev_put(bdev, mode | FMODE_EXCL); > > Somewhat related question: Should we allow userspace to initiate a fs > shutdown through the block device? Let's say you're preparing to yank > /dev/sda and want to kill anything attached to it or its partitions? > Without having to walk through however many mount namespaces there are > to find the mountpoints? That's kinda what we're doing here. Or do you mean even more advanced notice by having another callout before stopping I/O so that we could write out all log buffers? It's probably doable, but I'm not convinced that this use case is worth maintaining and testing the kernel code for it.
