On 11/08/2011 12:16 AM, Xu He Jie wrote:
As the description of removing CDROM media from http://wiki.libvirt.org/page/QEMUSwitchToLibvirt#eject_DEV
Hmm. virsh attach-disk --type cdrom --mode readonly myguest "" hdc might look a bit nicer as: virsh attach-disk --type cdrom --mode readonly myguest --target hdc except that we marked --source as a required argument, so we have to provide something even when there is no real source. So I agree that we need your patch at a bare minimum to support this documented command line for adding a cdrom drive without a disk. Meanwhile, conf/domain_conf.c has this comment: /* People sometimes pass a bogus '' source path when they mean to omit the source element completely. eg CDROM without media. This is just a little compatability check to help those broken apps */ if (source && STREQ(source, "")) VIR_FREE(source); So while passing an empty string down through the XML eventually does the right thing, we make it sound like it is a gross hack, and that it would be nicer if virsh weren't one of "those broken apps" that exploits the xml hack.
Add flag 'VSH_OFLAG_EMPTY_OK' to the option 'source' of attach-disk
Signed-off-by: Xu He Jie<xuhj@linux.vnet.ibm.com> --- tools/virsh.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/tools/virsh.c b/tools/virsh.c index 5544a41..e7eae74 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -11569,7 +11569,7 @@ static const vshCmdInfo info_attach_disk[] = {
static const vshCmdOptDef opts_attach_disk[] = { {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")}, - {"source", VSH_OT_DATA, VSH_OFLAG_REQ, N_("source of disk device")}, + {"source", VSH_OT_DATA, VSH_OFLAG_REQ | VSH_OFLAG_EMPTY_OK, N_("source of disk device")},
ACK to your change, but I'm reformatting it to fit 80 columns, then squashing in this additional change before pushing so that virsh will be a model citizen: diff --git i/tools/virsh.c w/tools/virsh.c index e7eae74..eed727b 100644 --- i/tools/virsh.c +++ w/tools/virsh.c @@ -11569,7 +11569,8 @@ static const vshCmdInfo info_attach_disk[] = { static const vshCmdOptDef opts_attach_disk[] = { {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")}, - {"source", VSH_OT_DATA, VSH_OFLAG_REQ | VSH_OFLAG_EMPTY_OK, N_("source of disk device")}, + {"source", VSH_OT_DATA, VSH_OFLAG_REQ | VSH_OFLAG_EMPTY_OK, + N_("source of disk device")}, {"target", VSH_OT_DATA, VSH_OFLAG_REQ, N_("target of disk device")}, {"driver", VSH_OT_STRING, 0, N_("driver of disk device")}, {"subdriver", VSH_OT_STRING, 0, N_("subdriver of disk device")}, @@ -11754,6 +11755,10 @@ cmdAttachDisk(vshControl *ctl, const vshCmd *cmd) if (vshCommandOptString(cmd, "source", &source) <= 0) goto cleanup; + /* Allow empty string as a placeholder that implies no source, for + * use in adding a cdrom drive with no disk. */ + if (!*source) + source = NULL; if (vshCommandOptString(cmd, "target", &target) <= 0) goto cleanup; @@ -11808,9 +11813,10 @@ cmdAttachDisk(vshControl *ctl, const vshCmd *cmd) if (driver || subdriver || cache) virBufferAddLit(&buf, "/>\n"); - virBufferAsprintf(&buf, " <source %s='%s'/>\n", - (isFile) ? "file" : "dev", - source); + if (source) + virBufferAsprintf(&buf, " <source %s='%s'/>\n", + (isFile) ? "file" : "dev", + source); virBufferAsprintf(&buf, " <target dev='%s'/>\n", target); if (mode) virBufferAsprintf(&buf, " <%s/>\n", mode); -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org