Messages in this thread | | | Date | Thu, 14 Sep 2000 15:14:28 -0700 | From | John Byrne <> | Subject | Re: Getting past the 16-bit dev_t limitation. |
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Helge Hafting wrote: > > John Byrne wrote: > > > 1.) Can anyone tell me if there is a (Linus approved) solution in the > > works for this for the 2.4.xx kernel series? > > > I am also curious whether there are plans to do away with the whole > > concept of major/minor numbers; > > Consider reading up on devfs, which is now integrated into 2.4. > Basically it is a (optional) special filesystem, where a driver register > a > name for each device it serves, possibly in a subdirectory. > (I.e. all audio devices in /dev/sound/..., all scsi stuff under > /dev/scsi/...) > > This device filesystem is mounted at /dev during boot, instead of having > a > /dev directory with special files. > > Helge Hafting
Both you and Martin told me to look as devfs. I had, but I looked again to see what I had missed.
I had somehow missed that internally devfs allows majors and minors to both be 16-bits. However, the interface to the kernel for this information and thence to the user world is still looks to be the 16-bit kdev_t; so exceeding 255 for your minor number would "bleed" onto your major number and cause aliasing of devices in some cases. How bad the effects would be, I don't know.
Thanks,
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