Re: [RFC][5/11][MANUX] Kernel compatibility : major/minor numbers

Emmanuel Colbus
2014-04-15T17:39:29Z

Le 15/04/2014 17:02, Austin S Hemmelgarn a écrit :
> On 2014-04-15 09:42, Emmanuel Colbus wrote:
>> Now, back to the filesystem...
>>
>> In order to associate devices to their files, the Linux kernel uses
>> their major and minor numbers. However, mine doesn't; instead, I've
>> attributed myself a single group of values (major=0, minor=0, for both
>> character-mode and block-mode special files), with the meaning (for the
>> userspace) "you cannot identify the content of this file based on its
>> major and minor numbers".
>>
>> As for my kernel, there is a syscall to associate such files with their
>> proper peripherals (asper(2)), after which it internally identifies them
>> using their inode and partition numbers; as for userspace, it has no
>> choice but to use their names, as usual.
>>
>> Do you have any objection to my taking of these values?
>>
>
> According to Documentation/devices.txt:
> 0 Unnamed devices (e.g. non-device mounts)
> 0 = reserved as null device number
>
> Based on this, I would say that you are probably better off using one of
> the local use numbers (60-63 and 250-254 are reserved for local and
> experimental use)
>

I see... Well, I think I'm going to take 254/0 for this then.

Thank you!

Emmanuel