Supporting human parsable journal_dev specifiers

["Theodore Ts'o" <tytso@mit.edu>]

I have a user request that mount be able to interpret the device
specifier for the journal_dev mount option, so that instead of having
to type something like

   mount -o journal_dev=0x0803 ....

they could unstead use: "journal_dev=/dev/sda3" or even
"journal_dev=LABEL=ext_journal".  I assume the right way to do this is
a mount helper?  Or is this something that you would be willing to
accept as a patch into util-linux?

If it is a mount helper, what's the best way to do things?  Simply
parse through the mount options until finding the journal_dev one, and
then calling blkid or stat as necessary to interpret the argument, and
then re-exec mount with the modified mount option?  Or is there some
gotchas involved with doing this?

Thanks,

						- Ted