Messages in this thread |  | | From | "Grant R. Guenther" <> | Subject | Exclusive access to block devices | Date | Fri, 3 May 1996 08:35:54 -0400 (EDT) |
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A friend and I are working on a program to access Iomega's special features for the ZIP drive. It's easy enough to use the SCSI_SEND_COMMAND ioctl to actually do the things we need from a user mode program, but these ioctls are things that should not be done when the drive is otherwise in use. 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.)
My friend wants to add the new ioctls into scsi_ioctl.c, but I'm arguing that vendor-specific functions ought not to be in the kernel.
I feel certain that I'm missing something obvious - anyone care to enlighten me ? :-)
Should we have a general low-level "lock this device for exclusive use" ioctl for all block devices ? The access counters required to implement it are all there already.
-------------------------------------------------------------------------- Grant R. Guenther grant@torque.net --------------------------------------------------------------------------
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