Re: [Qemu-devel] [PATCH 11/13] 9p: darwin: Mark mknod as unsupported

[Keno Fischer]

On Thu, May 31, 2018 at 6:56 PM, Keno Fischer <address@hidden> wrote:
>>> My concern was that allowing this would cause unexpected
>>> behavior, since the device numbers will differ between OS X
>>> and Linux. Though maybe this isn't the place to worry about
>>> that.
>>
>> The numbers may differ indeed but we don't really care since the
>> server never opens device files. This is just a directory entry.
>
> Ok, let me try to implement it. However, I don't think it is possible
> to implement mknodat (or at least I can't think of how) on Darwin
> directly. I could use regular mknod, but presumably, this is used
> to avoid a race condition between creating the device and setting
> the permissions. Can you think of a good way to resolve that?

Would it work to fchdir in to the directory and use a cwd-relative
mknod, then fchdir back? Or do we need to maintain the cwd
while in this code?