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Date: Sat, 14 Jun 2008 12:06:58 -0700
From: Avi Kivity <avi@qumranet.com>
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Subject: Re: [Qemu-devel] [PATCH] Merge NBD client/server int qemu-nbd
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To: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: qemu-devel@nongnu.org

Laurent Vivier wrote:
> Le samedi 14 juin 2008 =C3=A0 20:18 +0300, Avi Kivity a =C3=A9crit :
>  =20
>> Laurent Vivier wrote:
>>    =20
>>> int timeout =3D 5;
>>> while ((fd =3D open(device, O_RDWR)) =3D=3D -1 && timeout--)
>>>     sleep(1);
>>>
>>> Any suggestion ???
>>>
>>>  =20
>>>      =20
>> /sbin/udevsettle
>>    =20
>
> Why do you think udev is involved at this moment ?
>
> /dev/nbd0 is created when the module is loaded (thus before) and the
> partitions when the partition table is read (from within the open).
>  =20

It is udev that creates the devices, based on events it receives from=20
the kernel.  Calling udevsettle after the kernel instructs udev to=20
create the device files will wait until they are actually created.

--=20
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.