Messages in this thread |  | | Date | Mon, 14 May 2001 12:57:39 -0700 | From | "H. Peter Anvin" <> | Subject | Re: LANANA: To Pending Device Number Registrants |
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Jeff Garzik wrote: > > "H. Peter Anvin" wrote: > > Linus Torvalds has requested a moratorium on new device number > > assignments. His hope is that a new and better method for device space > > handing will emerge as a result. > > Here's my suggestion for a solution. > > Once I work through a bunch of net driver problems, I want to release a > snapshot block device driver (freezes a blkdev in time). For this, I > needed a block major. After hearing about the device number freeze, I > was wondering if this solution works: > > Register block device using existing API, and obtain a dynamically > assigned major number. Export a tiny ramfs which lists all device > nodes. Mounted on /dev/snap, /dev/snap/0 would be the first blkdev for > snap's dynamically assigned major. (Al Viro said he has skeleton code > to create such an fs, IIRC) > > This solution > (a) keeps from grot-ing up /proc even more [I had considered > proc_mknod() until viro talked me out of it] > (b) does not require centrally assigned majors and minors. > (c) does not require devfs. most distros ship without it afaik, and > switching to it is not an overnight process, and requires devfsd to be > useful in the real world. >
It does, however, not manage permissions, nor does it provide for a sane namespace (it exposes too many internal implementation details in the interface -- in particular, the driver becomes part of the namespace, and devices move around between drivers regularly.)
-hpa
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