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    SubjectRe: Larger dev_t
    On Tue, 27 Mar 2001, Linus Torvalds wrote:

    > ... lots of stuff removed ...
    >
    > So in /dev, there are two problems: we are getting painfully close to
    > major numbers with 8 bits, and we've run out of minors several times. In
    > fact, a lot of the reason for the dearthness of major numbers is the fact
    > that we use multiple majors for some stuff that really wants many minors.
    >

    Well, one solution to this on the long term comes quite naturally:
    make major/minor separation a policy, i.e., as in network/host
    IP numbers. That is, in addition to 32-bit dev_t there would
    be a 32-bit devmask_t that when &-ed with dev_t would yield the
    major. The default, for compatibility reasons will be devmask of 255
    (or -1+1<<12). For example, all floppies would fall into 2/8 major
    (using IP address notation). Obviously, all this is not advantageous
    on the short term, but in the absence of better ideas, this can give
    some flexibility when allocating/shifting to new majors/minors...Of
    course, namespaces approach is even better, but when will all drivers
    be converted to support them?

    Cheers,

    Pjotr


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