Re: Exclusive access to block devices

Bernd Eckenfels (
4 May 1996 04:18:16 GMT

Grant R. Guenther <> wrote:
> There doesn't appear to be any general way to specify that an
> ioctl should only be executed if the access count is == 1, or to
> test that a block device is not mounted or otherwise open ... (While
> an absolute race-free lock would be nice, a simple busy test would be
> adequate for the application.)

You can use O_EXCL in conjunction with fstat(). The generic SCSI driver
seems to support that. Problem may be root access, not sure if it works, but
thats what the flag is for :)


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