USB memory stick hotswap problems
Lucas.James at LDJcs.Com.Au
Sat Sep 25 18:15:32 PDT 2004
On Sun, 26 Sep 2004 10:29 am, Jeremy Chadwick wrote:
> Can't usbd (or better yet, usbd.conf) be modified or changed in some way
> to automatically handle the unmounting of any existing filesystems that
> match the device which is mounted?
that won't work because usbd only gets the notification of something being
unplugged *after* the fact, and it's too late to do unmounting then.
And it can't be modified, because the kernel has no idea when the user is
going to yank out the cable.
> Seems like we're eventually going to need this to make hot-swappable USB
> devices more friendly. I understand why you must unmount a device
> before SCSI CAM gets disconnected from it, but it just seems that this
> should be a job for usbd.
the only way you can ensure data integrity on user-removable devices is to
mount them with -o sync.
We should be telling the kernel at some point that this is a removable device,
and not have the kernel complain if we umount it when the device has already
disappeared (assuming that we have mounted it with -o sync).
The only possible interpretation of any research whatever in the
`social sciences' is: some do, some don't.
-- Ernest Rutherford
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