On Thu, 2018-01-04 at 11:17 +0100, Michal Privoznik wrote: > https://bugzilla.redhat.com/show_bug.cgi?id=1528502 > > So imagine you have /dev/blah symlink which points to /dev/sda. > You attach /dev/blah as disk to your domain. Libvirt correctly > creates the /dev/blah -> /dev/sda symlink in the qemu namespace. > However, then you detach the disk, change the symlink so that it > points to /dev/sdb and tries to attach the disk again. This time, > however, the attach fails (well, qemu attaches wrong disk) > because the code assumes that symlinks don't change. Well they > do. > > This is inspired by test fix written by Eduardo Habkost. > > Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx> > --- > src/qemu/qemu_domain.c | 22 ++++++++++++++++------ > 1 file changed, 16 insertions(+), 6 deletions(-) > > diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c > index 70fb40650..5f29d1ad5 100644 > --- a/src/qemu/qemu_domain.c > +++ b/src/qemu/qemu_domain.c > @@ -9737,13 +9737,23 @@ qemuDomainAttachDeviceMknodHelper(pid_t pid ATTRIBUTE_UNUSED, > > if (isLink) { > VIR_DEBUG("Creating symlink %s -> %s", data->file, data->target); > + > + /* First, unlink the symlink target. Symlinks change and > + * therefore we have no guarantees that pre-existing > + * symlink is still valid. */ > + if (unlink(data->file) < 0 && Here... > + errno != ENOENT) { > + virReportSystemError(errno, > + _("Unable to remove symlink %s"), > + data->file); ... and here, shouldn't you be using data->target instead of data->file? -- Andrea Bolognani / Red Hat / Virtualization -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
