[libvirt] [Qemu-devel] [PATCH v4 7/7] osdep: Enable qemu_open to dup pre-opened fd

Corey Bryant coreyb at linux.vnet.ibm.com
Mon Jun 25 16:18:38 UTC 2012



On 06/25/2012 11:26 AM, Kevin Wolf wrote:
> Am 25.06.2012 16:34, schrieb Eric Blake:
>>> Also, I noticed in the fnctl man page that F_SETFL:  "On Linux this
>>> command can change only the O_APPEND, O_ASYNC, O_DIRECT, O_NOATIME, and
>>> O_NONBLOCK flags."  So I'll only set/unset these flags.
>>
>> O_NDELAY is the obsolete spelling of O_NONBLOCK; which means the only
>> other flags in your list not supported by Linux are O_LARGEFILE (which I
>> said was pointless), O_NOCTTY (which only has an impact at open() and
>> not later on, so it is not worth worrying about), and O_SYNC (so for
>> that one, you should error out if not set correctly, as the difference
>> between O_SYNC on vs. off is significant).
>
> As far as I know, newer kernels can change O_SYNC with fcntl, so it's
> probably worth trying, but you'd have to check if it has really been set.
>
> Kevin
>

Ok I'll test it out and change O_SYNC if possible.  Thanks.

-- 
Regards,
Corey





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