Phillip Susi <psusi@xxxxxxxxxx> wrote: > > > But I suspect we could do an even better job if we did that in userspace. > > > > The logic to determine whether the new device is the same as the old device > > can be arbitrarily complex, with increasing levels of success. Various > > heuristics can be applied, some of which will involve knowledge of > > filesystem layout, etc. > > > > So would it not be possible to optionally punt the device naming decision > > up to the hotplug scripts? So code up there can go do direct-IO reads of > > the newly-present blockdev, use filesytem layout knowledge, peek at UUIDs, > > superblocks, disk labels, partition tables, inode numbering, etc? Go look > > up a database, work out what that filesystem was doing last time we saw it, > > etc? > > > > We could of course add things to the filesystems to help this process, but > > it'd be good if all the state tracking and magic didn't have to be locked > > up in the kernel. > > > Hrm... interesting but sounds like that could be sticky. For instance, > what if the user script that does the verifying happens to be ON the > volume to be verified? Well that would be a bug. Solutions would be a) don't put the scripts on a removable/power-downable device or b) use tmpfs.
