[PKT_SCHED]: Cleanup qdisc creation and alignment macros

Adds qdisc_alloc() to share code between qdisc_create()
and qdisc_create_dflt(). Hides the qdisc alignment behind
macros and makes use of them.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 37 insertions, 47 deletions

diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 2f494a20d512..6492e7363d84 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -13,13 +13,12 @@ struct qdisc_walker
 
 extern rwlock_t qdisc_tree_lock;
 
-#define QDISC_ALIGN             32
-#define QDISC_ALIGN_CONST       (QDISC_ALIGN - 1)
+#define QDISC_ALIGNTO           32
+#define QDISC_ALIGN(len)        (((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
 
 static inline void *qdisc_priv(struct Qdisc *q)
 {
-        return (char *)q + ((sizeof(struct Qdisc) + QDISC_ALIGN_CONST)
-                              & ~QDISC_ALIGN_CONST);
+        return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
 }
 
 /* 
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index c76d34e62ff6..7b6ec9986715 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -173,6 +173,7 @@ extern void dev_activate(struct net_device *dev);
 extern void dev_deactivate(struct net_device *dev);
 extern void qdisc_reset(struct Qdisc *qdisc);
 extern void qdisc_destroy(struct Qdisc *qdisc);
+extern struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops);
 extern struct Qdisc *qdisc_create_dflt(struct net_device *dev,
                                        struct Qdisc_ops *ops);
 
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 05e6e0a799da..1ef482ba6b36 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -399,10 +399,8 @@ qdisc_create(struct net_device *dev, u32 handle, struct rtattr **tca, int *errp)
 {
         int err;
         struct rtattr *kind = tca[TCA_KIND-1];
-        void *p = NULL;
         struct Qdisc *sch;
         struct Qdisc_ops *ops;
-        int size;
 
         ops = qdisc_lookup_ops(kind);
 #ifdef CONFIG_KMOD
@@ -437,43 +435,23 @@ qdisc_create(struct net_device *dev, u32 handle, struct rtattr **tca, int *errp)
         if (ops == NULL)
                 goto err_out;
 
-        /* ensure that the Qdisc and the private data are 32-byte aligned */
-        size = ((sizeof(*sch) + QDISC_ALIGN_CONST) & ~QDISC_ALIGN_CONST);
-        size += ops->priv_size + QDISC_ALIGN_CONST;
-
-        p = kmalloc(size, GFP_KERNEL);
-        err = -ENOBUFS;
-        if (!p)
+        sch = qdisc_alloc(dev, ops);
+        if (IS_ERR(sch)) {
+                err = PTR_ERR(sch);
                 goto err_out2;
-        memset(p, 0, size);
-        sch = (struct Qdisc *)(((unsigned long)p + QDISC_ALIGN_CONST)
-                               & ~QDISC_ALIGN_CONST);
-        sch->padded = (char *)sch - (char *)p;
-
-        INIT_LIST_HEAD(&sch->list);
-        skb_queue_head_init(&sch->q);
+        }
 
-        if (handle == TC_H_INGRESS)
+        if (handle == TC_H_INGRESS) {
                 sch->flags |= TCQ_F_INGRESS;
-
-        sch->ops = ops;
-        sch->enqueue = ops->enqueue;
-        sch->dequeue = ops->dequeue;
-        sch->dev = dev;
-        dev_hold(dev);
-        atomic_set(&sch->refcnt, 1);
-        sch->stats_lock = &dev->queue_lock;
-        if (handle == 0) {
+                handle = TC_H_MAKE(TC_H_INGRESS, 0);
+        } else if (handle == 0) {
                 handle = qdisc_alloc_handle(dev);
                 err = -ENOMEM;
                 if (handle == 0)
                         goto err_out3;
         }
 
-        if (handle == TC_H_INGRESS)
-                sch->handle =TC_H_MAKE(TC_H_INGRESS, 0);
-        else
-                sch->handle = handle;
+        sch->handle = handle;
 
         if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS-1])) == 0) {
                 qdisc_lock_tree(dev);
@@ -489,12 +467,11 @@ qdisc_create(struct net_device *dev, u32 handle, struct rtattr **tca, int *errp)
         }
 err_out3:
         dev_put(dev);
+        kfree((char *) sch - sch->padded);
 err_out2:
         module_put(ops->owner);
 err_out:
         *errp = err;
-        if (p)
-                kfree(p);
         return NULL;
 }
 
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 7683b34dc6a9..73e218e646ac 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -395,24 +395,23 @@ static struct Qdisc_ops pfifo_fast_ops = {
         .owner          =       THIS_MODULE,
 };
 
-struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
+struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops)
 {
         void *p;
         struct Qdisc *sch;
-        int size;
+        unsigned int size;
+        int err = -ENOBUFS;
 
         /* ensure that the Qdisc and the private data are 32-byte aligned */
-        size = ((sizeof(*sch) + QDISC_ALIGN_CONST) & ~QDISC_ALIGN_CONST);
-        size += ops->priv_size + QDISC_ALIGN_CONST;
+        size = QDISC_ALIGN(sizeof(*sch));
+        size += ops->priv_size + (QDISC_ALIGNTO - 1);
 
         p = kmalloc(size, GFP_KERNEL);
         if (!p)
-                return NULL;
+                goto errout;
         memset(p, 0, size);
-
-        sch = (struct Qdisc *)(((unsigned long)p + QDISC_ALIGN_CONST) 
-                               & ~QDISC_ALIGN_CONST);
-        sch->padded = (char *)sch - (char *)p;
+        sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
+        sch->padded = (char *) sch - (char *) p;
 
         INIT_LIST_HEAD(&sch->list);
         skb_queue_head_init(&sch->q);
@@ -423,11 +422,24 @@ struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
         dev_hold(dev);
         sch->stats_lock = &dev->queue_lock;
         atomic_set(&sch->refcnt, 1);
+
+        return sch;
+errout:
+        return ERR_PTR(-err);
+}
+
+struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
+{
+        struct Qdisc *sch;
+        
+        sch = qdisc_alloc(dev, ops);
+        if (IS_ERR(sch))
+                goto errout;
+
         if (!ops->init || ops->init(sch, NULL) == 0)
                 return sch;
 
-        dev_put(dev);
-        kfree(p);
+errout:
         return NULL;
 }
 
@@ -591,6 +603,7 @@ EXPORT_SYMBOL(__netdev_watchdog_up);
 EXPORT_SYMBOL(noop_qdisc);
 EXPORT_SYMBOL(noop_qdisc_ops);
 EXPORT_SYMBOL(qdisc_create_dflt);
+EXPORT_SYMBOL(qdisc_alloc);
 EXPORT_SYMBOL(qdisc_destroy);
 EXPORT_SYMBOL(qdisc_reset);
 EXPORT_SYMBOL(qdisc_restart);