Re: [libvirt] Consultation of the patch "util: Prepare helpers for unpriv_sgio setting"

On 2013年03月13日 11:04, yuxh wrote: > To Osier Yang > > Sorry for disturbing you on the working time, but I really need your > help. > I met a problem when I do the virtualization test on the environment of > (Host: RHEL6.4GA. Guest: RHEL6.4GA) and it seems to have relationship > with your patch of "util: Prepare helpers for unpriv_sgio setting". Never mind, it's the bug I produced. :( > > I added a disk to virtio-scsi bus through the VM's XML file like this: > <disk type='block' device='disk'> > <driver name='qemu' type='raw' io='threads'/> > <source dev='/mnt/test.raw'/> > <target dev='sdb' bus='scsi'/> > <shareable/> > </disk> Then when I started the VM, I met the error. > [root@build SOURCES]# virsh start pan64ga > error: Failed to start domain pan64ga > error: Unable to get minor number of device '/mnt/test.raw': Invalid > argument > > [root@build SOURCES]# > > I tried other source files and other way of using if and I found: > 1). If we use the files which format is raw, qed and qcow2 as the disk > this error occur again. > 2). If we use partition(such as /dev/sdb1) or whole disk(such as > /dev/sdb) this error doesn't occur. > 3). If we delete the "<shareable/>" then files, partition and disk all > can be used correctly. > > And I investigate the error msg. it is returned by qemuGetSharedDiskKey > fuction. > char * > qemuGetSharedDiskKey(const char *disk_path) > { > ... > // error occur here. return value is -22 > if ((rc = virGetDeviceID(disk_path, &maj, &min)) < 0) { > virReportSystemError(-rc, > _("Unable to get minor number of device '%s'"), > disk_path); > return NULL; > } > ... > } > > Go on the virGetDeviceID fuction: > int > virGetDeviceID(const char *path, int *maj, int *min) > { > ... > > if (!S_ISBLK(sb.st_mode)) { > VIR_FREE(canonical_path); > return -EINVAL; // error occur here and it return -22 > } > ... > } > > So the error occur place is "S_ISBLK(sb.st_mode)" and I tried compiled > the libvirt with these lines deleted and the error didn't happen again. > Also I checked the disk if VM and it worked well. > I found this fuction virGetDeviceID is come from your patch of "util: > Prepare helpers for unpriv_sgio setting". But I am not familiar with > libvirt. > So I have to consult with you about whether this "S_ISBLK" check is > vital and If we can delete it or > find out some method to avoid this error so we can use the file as > shared disk in VM. It's fixd by https://www.redhat.com/archives/libvir-list/2013-February/msg01024.html, which is already committed to upstream, and backported to 6.4.z. You will see the fix in the new build, which will come soon. Regards, Osier