Re: [libvirt] [PATCH] qemu: Provide default LUN=0 for iSCSI if not provided

https://bugzilla.redhat.com/show_bug.cgi?id=1477880 If the "/#" is missing from the provided iSCSI path, then we need to provide the default LUN of /0; otherwise, QEMU will fail to parse the URL causing a failure to either create the guest or hotplug attach the storage. Alter the command lines generated appropriately. This change does not effect the XML input files. One 'side effect' of this for the argv2xml is that if a "/0" is found on the command line, then the generated XML would need to add the "/0" to the output XML since it wouldn't be known whether it existed or not at qemu process creation time. Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; --- NB: Investigated the history quite a bit between QEMU and libiscsi and it seems as though this probably never worked and of course never "tested" in a real environment. Ironically, in qapi/block-core.json, it is claimed that the LUN would default to 0, but the block/iscsi.c code that calls iscsi_parse_full_url would never (AFAICT) have supported not supplying some LUN on the command line. src/qemu/qemu_command.c | 20 ++++++++++++++++---- .../qemuargv2xml-disk-drive-network-iscsi.args | 2 +- .../qemuargv2xml-disk-drive-network-iscsi.xml | 2 +- .../qemuxml2argv-disk-drive-network-iscsi-lun.args | 2 +- .../qemuxml2argv-disk-drive-network-iscsi.args | 2 +- .../qemuxml2argv-hostdev-scsi-lsi-iscsi.args | 2 +- .../qemuxml2argv-hostdev-scsi-virtio-iscsi.args | 2 +- 7 files changed, 22 insertions(+), 10 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index ed8cb6e..cff84de 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -830,10 +830,22 @@ qemuBuildNetworkDriveURI(virStorageSourcePtr src, src->volume, src->path) < 0) goto cleanup; } else { - if (virAsprintf(&uri->path, "%s%s", - src->path[0] == '/' ? "" : "/", - src->path) < 0) - goto cleanup; + if (src->protocol == VIR_STORAGE_NET_PROTOCOL_ISCSI && + !strchr(src->path, '/')) { + + /* The details of iqn is defined by RFC 3720 and 3721, but + * we just need to make sure there's a lun provided. If not + * provided, then default to zero. If ISCSI LUN is provided + * by /dev/disk/by-path/... , then that path will have the + * specific lun requested. */ + if (virAsprintf(&uri->path, "/%s/0", src->path) < 0) + goto cleanup; + } else { + if (virAsprintf(&uri->path, "%s%s", + src->path[0] == '/' ? "" : "/", + src->path) < 0) + goto cleanup; + } } }