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

Oleg Nesterov
2006-11-01T18:26:55Z

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>

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);