[libvirt] PATCH: 4/5: Locking in the LXC driver

[Dan Smith]

DB> @@ -104,8 +117,12 @@ static virDomainPtr lxcDomainLookupByID(
DB>                                          int id)
DB>  {
DB>      lxc_driver_t *driver = (lxc_driver_t *)conn->privateData;
DB> -    virDomainObjPtr vm = virDomainFindByID(&driver->domains, id);
DB> +    virDomainObjPtr vm;
DB>      virDomainPtr dom;
DB> +
DB> +    lxcDriverLock(driver);
DB> +    vm = virDomainFindByID(&driver->domains, id);
DB> +    lxcDriverUnlock(driver);

DB>      if (!vm) {
DB>          lxcError(conn, NULL, VIR_ERR_NO_DOMAIN, NULL);
DB> @@ -117,6 +134,7 @@ static virDomainPtr lxcDomainLookupByID(
dom-> id = vm->def->id;
DB>      }

DB> +    virDomainUnlock(vm);
DB>      return dom;
DB>  }

Can you explain why you're unlocking the vm in all of these functions
without first the corresponding lock operation?

DB> @@ -1091,17 +1230,20 @@ static int lxcShutdown(void)
DB>   */
DB>  static int
DB>  lxcActive(void) {
DB> -    unsigned int i;
DB> +    unsigned int i, active = 0;

DB>      if (lxc_driver == NULL)
DB>          return(0);

DB> -    for (i = 0 ; i < lxc_driver->domains.count ; i++)
DB> +    lxcDriverLock(lxc_driver);
DB> +    for (i = 0 ; i < lxc_driver->domains.count ; i++) {
DB> +        virDomainLock(lxc_driver->domains.objs[i]);
DB>          if (virDomainIsActive(lxc_driver->domains.objs[i]))
DB> -            return 1;
DB> +            active = 1;
DB> +        virDomainUnlock(lxc_driver->domains.objs[i]);
DB> +    }

DB> -    /* Otherwise we're happy to deal with a shutdown */
DB> -    return 0;
DB> +    return active;
DB>  }

It looks to me like you're taking the driver lock and not releasing it
on exit.

-- 
Dan Smith
IBM Linux Technology Center
Open Hypervisor Team
email: danms at us.ibm.com