[PATCH] taskstats: factor out reply assembling

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>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@sgi.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 28 insertions, 27 deletions

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 7d793d6b1e90..d2a41339f37b 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -343,6 +343,25 @@ static int parse(struct nlattr *na, cpumask_t *mask)
         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;
@@ -350,7 +369,6 @@ static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
         struct taskstats stats;
         void *reply;
         size_t size;
-        struct nlattr *na;
         cpumask_t mask;
 
         rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask);
@@ -382,27 +400,21 @@ static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
                 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:
@@ -446,7 +458,6 @@ void taskstats_exit(struct task_struct *tsk, int group_dead)
         void *reply;
         size_t size;
         int is_thread_group;
-        struct nlattr *na;
 
         if (!family_registered)
                 return;
@@ -481,27 +492,17 @@ void taskstats_exit(struct task_struct *tsk, int group_dead)
         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);