taskstats: separate taskstats commands

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>

1 files changed, 78 insertions, 40 deletions

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 5a651aa63d61..9970cae04f15 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -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;