taskstats: separate taskstats commands
Michael Holzheu [Wed, 27 Oct 2010 22:34:44 +0000 (15:34 -0700)]
Move each taskstats command into a single function.  This makes the code
more readable and makes it easier to add new commands.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/taskstats.c

index 5a651aa..9970cae 100644 (file)
@@ -430,39 +430,46 @@ err:
        return rc;
 }
 
-static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
+static int cmd_attr_register_cpumask(struct genl_info *info)
 {
-       int rc;
-       struct sk_buff *rep_skb;
-       struct taskstats *stats;
-       size_t size;
        cpumask_var_t mask;
+       int rc;
 
        if (!alloc_cpumask_var(&mask, GFP_KERNEL))
                return -ENOMEM;
-
        rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask);
        if (rc < 0)
-               goto free_return_rc;
-       if (rc == 0) {
-               rc = add_del_listener(info->snd_pid, mask, REGISTER);
-               goto free_return_rc;
-       }
+               goto out;
+       rc = add_del_listener(info->snd_pid, mask, REGISTER);
+out:
+       free_cpumask_var(mask);
+       return rc;
+}
 
+static int cmd_attr_deregister_cpumask(struct genl_info *info)
+{
+       cpumask_var_t mask;
+       int rc;
+
+       if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+               return -ENOMEM;
        rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask);
        if (rc < 0)
-               goto free_return_rc;
-       if (rc == 0) {
-               rc = add_del_listener(info->snd_pid, mask, DEREGISTER);
-free_return_rc:
-               free_cpumask_var(mask);
-               return rc;
-       }
+               goto out;
+       rc = add_del_listener(info->snd_pid, mask, DEREGISTER);
+out:
        free_cpumask_var(mask);
+       return rc;
+}
+
+static int cmd_attr_pid(struct genl_info *info)
+{
+       struct taskstats *stats;
+       struct sk_buff *rep_skb;
+       size_t size;
+       u32 pid;
+       int rc;
 
-       /*
-        * Size includes space for nested attributes
-        */
        size = nla_total_size(sizeof(u32)) +
                nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
 
@@ -471,33 +478,64 @@ free_return_rc:
                return rc;
 
        rc = -EINVAL;
-       if (info->attrs[TASKSTATS_CMD_ATTR_PID]) {
-               u32 pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]);
-               stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid);
-               if (!stats)
-                       goto err;
-
-               rc = fill_pid(pid, NULL, stats);
-               if (rc < 0)
-                       goto err;
-       } else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) {
-               u32 tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
-               stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid);
-               if (!stats)
-                       goto err;
-
-               rc = fill_tgid(tgid, NULL, stats);
-               if (rc < 0)
-                       goto err;
-       } else
+       pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]);
+       stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid);
+       if (!stats)
+               goto err;
+
+       rc = fill_pid(pid, NULL, stats);
+       if (rc < 0)
+               goto err;
+       return send_reply(rep_skb, info);
+err:
+       nlmsg_free(rep_skb);
+       return rc;
+}
+
+static int cmd_attr_tgid(struct genl_info *info)
+{
+       struct taskstats *stats;
+       struct sk_buff *rep_skb;
+       size_t size;
+       u32 tgid;
+       int rc;
+
+       size = nla_total_size(sizeof(u32)) +
+               nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
+
+       rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
+       if (rc < 0)
+               return rc;
+
+       rc = -EINVAL;
+       tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]);
+       stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid);
+       if (!stats)
                goto err;
 
+       rc = fill_tgid(tgid, NULL, stats);
+       if (rc < 0)
+               goto err;
        return send_reply(rep_skb, info);
 err:
        nlmsg_free(rep_skb);
        return rc;
 }
 
+static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
+{
+       if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK])
+               return cmd_attr_register_cpumask(info);
+       else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK])
+               return cmd_attr_deregister_cpumask(info);
+       else if (info->attrs[TASKSTATS_CMD_ATTR_PID])
+               return cmd_attr_pid(info);
+       else if (info->attrs[TASKSTATS_CMD_ATTR_TGID])
+               return cmd_attr_tgid(info);
+       else
+               return -EINVAL;
+}
+
 static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk)
 {
        struct signal_struct *sig = tsk->signal;