On Sat, Feb 11, 2012 at 01:30:16PM +0100, Matthias Schniedermeyer wrote: > For the umount thing, i think i could use inotify and wait for the > "umount"-event as inotify fortunately doesn't prevent umount, but that See: http://karelzak.blogspot.com/2011/12/monitor-list-of-currently-mounted.html > works a little against the spirit of autofs, as it only would work once > (at least in the case of setup by udev). > > All "solutions" taste a little strange for me, the udev-solution mainly > because i would have a dm-crypt "laying" around which may or may not be It's usually bad idea to call mount (or so) from udev rules (and it's often topic in udev mailing list). > used and the automatic tear-down after umount because what if it just > timed out and i want it to use again would only work with an exec-type > map where i could to the setup. Only doing the teardown of the dm-crypt > after the device is unplugged does not sound right to me either, because > i don't know if that is safe. My question if unplugging a device, with a > dm-crypt device in existence, is safe was met with silence. > > All crutches would not be needed if there was a "premount" and "postumount" > option/command in mount that could do something "just before mount" and > "just after umount". Either "per mount" or "always". > > I guess the easiest solution would be if mount would check for > /sbin/mount.premount and execute that before the mount took place, with > all the commandline parameters passed to the program and the same after > umount with /sbin/mount.postumount or something like that. I hope that next week we (I and dm-crypt maintainer) will publish our libblkasm (block device assemble library) draft. The goal is to have a shared library that will on demand assemble requested block device (dm-raid, mdraid, iscsi, loopdev, ...). The subsystem specific stuff will be in plug-ins (e.g. blkasm-crypt.so). The plan is to use the library from fsck or mount (or so..). > This solution would also make for e.g. "loop-aes" more easily usable, > currently one has to use a patched version of mount/losetup. With a Do you know that the latest cryptsetup is able to map loop-aes images by dm-crypt? > premount/postumount-command/option it would be possible to use an unpatched > mount-binary and do the loop-aes setup/teardown "somewhere else", which > would at least alleviate the need for a patched mount command for the > usecases where there is no interactivity (e.g. with a "cleartextkey" or > a gpg-key when a usable gpg-agent is running). Karel -- Karel Zak <kzak@xxxxxxxxxx> http://karelzak.blogspot.com -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
