Re: [Qemu-devel] [PATCH] iSCSI: add configuration variables for iSCSI

[Kevin Wolf <kwolf@redhat.com>]

Am 25.01.2012 16:57, schrieb Eric Blake:
> On 01/24/2012 11:47 PM, ronnie sahlberg wrote:
>> Read from an arbitrary filedescriptor inherited from the parent process :
>> 9<iscsi.conf ./x86_64-softmmu/qemu-system-x86_64 -enable-kvm -display
>> vnc=127.0.0.1:0 -drive file=iscsi://127.0.0.1/iqn.ronnie.test/1
>> -readconfig /proc/self/fd/9
> 
> That requires the existence of procfs, which is not portable (although
> it does work on Linux).  I'd rather see:
> 
> -readconfig fd:9
> 
> which matches things for -incoming; that is, if -readconfig starts with
> '/' or '.', it is a filename; otherwise, it is a protocol:value
> designation, where we recognize at least the fd: protocol where a value
> is the incoming fd, but we could also recognize things like exec:
> protocol which is an arbitrary command to use via popen.

Magic prefixes like this have one big problem: What if someone has a
config file called "fd:9"? We have the very same problem with protocols
in the block layer and while in the general case it's a convenient
syntax, we've come to hate it in cases where it misinterprets things.

Kevin