Re: [PATCH 1/2] taskstats: factor out reply assembling

Shailabh Nagar
2006-11-01T20:31:32Z

Oleg Nesterov wrote:
> Introduce mk_reply() helper which does all nla_put()s on reply.
>
> Saves 453 bytes and a preparation for the next patch.
>
> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

Acked-by: Shailabh Nagar <nagar@watson.ibm.com>

>
> taskstats.c | 55 ++++++++++++++++++++++++++++---------------------------
> 1 files changed, 28 insertions(+), 27 deletions(-)
>
> --- STATS/kernel/taskstats.c~5_factor 2006-10-31 16:33:56.000000000 +0300
> +++ STATS/kernel/taskstats.c 2006-11-01 14:00:03.000000000 +0300
> @@ -348,6 +348,25 @@ static int parse(struct nlattr *na, cpum
> return ret;
> }
>
> +static int mk_reply(struct sk_buff *skb, int type, u32 pid, struct taskstats *stats)
> +{
> + struct nlattr *na;
> + int aggr;
> +
> + aggr = TASKSTATS_TYPE_AGGR_TGID;
> + if (type == TASKSTATS_TYPE_PID)
> + aggr = TASKSTATS_TYPE_AGGR_PID;
> +
> + na = nla_nest_start(skb, aggr);
> + NLA_PUT_U32(skb, type, pid);
> + NLA_PUT_TYPE(skb, struct taskstats, TASKSTATS_TYPE_STATS, *stats);
> + nla_nest_end(skb, na);
> +
> + return 0;
> +nla_put_failure:
> + return -1;
> +}
> +
> static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
> {
> int rc = 0;
> @@ -355,7 +374,6 @@ static int taskstats_user_cmd(struct sk_
> struct taskstats stats;
> void *reply;
> size_t size;
> - struct nlattr *na;
> cpumask_t mask;
>
> rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask);
> @@ -387,27 +405,21 @@ static int taskstats_user_cmd(struct sk_
> if (rc < 0)
> goto err;
>
> - na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
> - NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, pid);
> - NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> - stats);
> + if (mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid, &stats))
> + goto nla_put_failure;
> } else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) {
> u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
> rc = fill_tgid(tgid, NULL, &stats);
> if (rc < 0)
> goto err;
>
> - na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
> - NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, tgid);
> - NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> - stats);
> + if (mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid, &stats))
> + goto nla_put_failure;
> } else {
> rc = -EINVAL;
> goto err;
> }
>
> - nla_nest_end(rep_skb, na);
> -
> return send_reply(rep_skb, info->snd_pid);
>
> nla_put_failure:
> @@ -451,7 +463,6 @@ void taskstats_exit(struct task_struct *
> void *reply;
> size_t size;
> int is_thread_group;
> - struct nlattr *na;
>
> if (!family_registered)
> return;
> @@ -486,27 +497,17 @@ void taskstats_exit(struct task_struct *
> if (rc < 0)
> goto err_skb;
>
> - na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_PID);
> - NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_PID, (u32)tsk->pid);
> - NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> - *tidstats);
> - nla_nest_end(rep_skb, na);
> -
> - if (!is_thread_group)
> - goto send;
> + if (mk_reply(rep_skb, TASKSTATS_TYPE_PID, tsk->pid, tidstats))
> + goto nla_put_failure;
>
> /*
> * Doesn't matter if tsk is the leader or the last group member leaving
> */
> - if (!group_dead)
> + if (!is_thread_group || !group_dead)
> goto send;
>
> - na = nla_nest_start(rep_skb, TASKSTATS_TYPE_AGGR_TGID);
> - NLA_PUT_U32(rep_skb, TASKSTATS_TYPE_TGID, (u32)tsk->tgid);
> - /* No locking needed for tsk->signal->stats since group is dead */
> - NLA_PUT_TYPE(rep_skb, struct taskstats, TASKSTATS_TYPE_STATS,
> - *tsk->signal->stats);
> - nla_nest_end(rep_skb, na);
> + if (mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tsk->tgid, tsk->signal->stats))
> + goto nla_put_failure;
>
> send:
> send_cpu_listeners(rep_skb, listeners);
>