RTFM. man automount.
I typed `man automount' but it gave me an error message. However,
someone else describe for me what automount can and can't do. It
seems it can unmount the floppy automatically in some cases, but not
when it is "in use".
The ability to handle removal of the floppy even when it is mounted
and "in use" will be important for non-hackers, so I think it is worth
some amount of effort. If the device is "in use" for an actual file
descriptor, it would be fine to make all subsequent operations on that
descriptor get errors. (One could replace all these descriptor with
some internal magic "always get an error" descriptor.)
As for the case of being "in use" as the working directory, it is
probably not too hard to handle that case "correctly" by setting a
flag that will be checked by file-name lookup routines.
Supermount seems to come closer to what I had in mind, and maybe could
do the job. But some people say it is not reliable. If it is made
reliable and gets included as a standard part of Linux, maybe it will
do the job.
But I wonder what happens if you remove the floppy while some file is
open on it. The program which has the open descriptor will have to
lose, but the system as a whole should not stumble. What will
supermount do in this case.
Keep in mind that MSDOS didn't
provide any caching, didn't have mmap() and even with all that it could be
b0rken badly by inserting/removing disks at wrong times.
If we want to make the system as good to use as Windows, for
non-hackers, we have to give high priority to user convenience for
non-hackers. We need to consider trading away features that are not
terribly beneficial, such as caching and mmap on a floppy disk.
Caching and mmap for files on the hard disk are useful features; for
floppies, they are of little benefit. The main use of floppies is for
file transfer and archiving. Caching and mmap are useful when you do
substantial work on a file, and for temporary files. But if you want
to make those operations efficient, the first thing you should do is
keep the files on the hard disk rather than on a floppy.
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This archive was generated by hypermail 2b29 : Thu Jun 15 2000 - 21:00:21 EST