[Libvir] [RFC][PATCH]: Make the iscsi storage backend mostly use sysfs

Hello, The newer version of iscsi-initiator-utils (6.2.0.865-0.2), available in the f8-updates repository, is required as part of the fix for a hang when doing iscsi logout (the other fix is in the 2.6.25 kernel). Unfortunately, this version also changes the output of the iscsiadm -m session -P 3 command; this output was being used to gather the scsi devices available in a pool and present them as volumes. Consequently, when starting an iSCSI pool on a machine with these newer versions of the iscsi tools, the pool will be successfully created but you won't be able to see any of the LUNs presented. The attached patch *lessens* our dependency on the iscsiadm output by using sysfs to gather the /dev devices. Note that this patch is not to be applied; I'm just putting it out there so people can take a look at it. DanB has suggested getting rid of our dependency on the iscsiadm output altogether is the way to go, and I agree with him there; this is mostly just a short-term solution, to possibly base future work on. Chris Lalancette