Serge E. Hallyn wrote:
> Quoting Oren Laadan (orenl@xxxxxxxxxxxxxxx):
>>> /* read the entire state of the current task */
>>> int restore_task(struct ckpt_ctx *ctx)
>>> {
>>> int ret;
>>> + struct cred *realcred, *ecred;
>>>
>>> - ret = restore_task_struct(ctx);
>>> + ret = restore_task_struct(ctx, &realcred, &ecred);
>> Actually, this is one of several cases where we need to restore some
>> resources but only apply it to a process at the end of its restart.
>>
>> Another example would be restoring pending signals and the blocked
>> signal mask in the future.
>>
>> I suggest that we keep a pointer on the task_struct to a structure
>> that will hold all that do-later work. The structure can encapsulate
>> the pending work either explicitly - e.g. a struct with fields like
>> realcred, ecred, signal mask, etc... - or implicitly, by reusing the
>> deferqueue framework, per task.
>>
>> Actually, that pointer can be kept on the ckpt_ctx structure, to be
>> used by the current-restarting-task only.
>>
>>> ckpt_debug("ret %d\n", ret);
>>> if (ret < 0)
>>> goto out;
>>> @@ -671,6 +1120,10 @@ int restore_task(struct ckpt_ctx *ctx)
>>> goto out;
>>> ret = restore_cpu(ctx);
>>> ckpt_debug("cpu: ret %d\n", ret);
>>> + if (ret < 0)
>>> + goto out;
>>> + ret = restore_creds(ctx, realcred, ecred);
>> ... and this would then be called from a restore_task_finalize()
>> function explicitly or implicitly by deferqueue_run().
>
> deferqueue_run() won't do, since that's done only once for the
> whole container, and we (as you say above) want to reuse one
> set of fields in the ckpt_ctx for each task's sys_restart() run.
I meant to add another deferqueue (either per task or on the
ckpt_ctx), for this specific purpose.
Oren.
>
> I'll go ahead and put fields in the ckpt_ctx this time around
> and use those, but won't go further right now as I'd be
> overgeneralizing before we have the signals and such work
> done. When we do that, we can move the restore_creds() fn
> if appropriate.
>
> -serge
>
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