Re: [libvirt] PATCH: 4/4: Add pivot_root support to container

DB> +static int lxcContainerMountNewFS(virDomainDefPtr vmDef) DB> +{ DB> + virDomainFSDefPtr tmp; DB> + DB> + /* Pull in rest of container's mounts */ DB> + for (tmp = vmDef->fss; tmp; tmp = tmp->next) { DB> + char *src; DB> + if (STREQ(tmp->dst, "/")) DB> + continue; DB> + // XXX fix DB> + if (tmp->type != VIR_DOMAIN_FS_TYPE_MOUNT) DB> + continue; DB> + DB> + if (asprintf(&src, "/.oldroot/%s", tmp->src) < 0) DB> + return -1; DB> + DB> + if (virFileMakePath(tmp->dst) < 0 || DB> + mount(src, tmp->dst, NULL, MS_BIND, NULL) < 0) { DB> + VIR_FREE(src); DB> + lxcError(NULL, NULL, VIR_ERR_INTERNAL_ERROR, DB> + _("failed to mount %s at %s for container: %s"), DB> + tmp->src, tmp->dst, strerror(errno)); DB> + return -1; DB> + } DB> + VIR_FREE(src); DB> + } DB> + return -1; Shouldn't this be "return 0"? AFAICT, this means this function will always fail and thus any domain with a root target will fail to start. If I change this to "return 0" I'm able to start such guests, with properly pivoted roots.

On a more general note, it seems like there are a lot of places where failures trigger a "return -1" that rolls completely up the stack with no error information getting logged. Since you have the excellent per-container logging functionality, can we increase the verbosity a little so that there is some way to diagnose where things are failing? Thus far, I've just started sprinkling fprintf()'s into the code until I start to narrow things down. I'd be glad to help with that after this goes in.