net: constify skbuff and Qdisc elements

Preliminary patch before tcp constification

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 21 insertions, 20 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1ebf1ea29d60..3411f22e7d16 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -853,9 +853,9 @@ static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
  *      The reference count is not incremented and the reference is therefore
  *      volatile. Use with caution.
  */
-static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
+static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
 {
-        struct sk_buff *list = ((struct sk_buff *)list_)->next;
+        struct sk_buff *list = ((const struct sk_buff *)list_)->next;
         if (list == (struct sk_buff *)list_)
                 list = NULL;
         return list;
@@ -874,9 +874,9 @@ static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
  *      The reference count is not incremented and the reference is therefore
  *      volatile. Use with caution.
  */
-static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
+static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
 {
-        struct sk_buff *list = ((struct sk_buff *)list_)->prev;
+        struct sk_buff *list = ((const struct sk_buff *)list_)->prev;
         if (list == (struct sk_buff *)list_)
                 list = NULL;
         return list;
@@ -1830,7 +1830,7 @@ static inline dma_addr_t skb_frag_dma_map(struct device *dev,
  *      Returns true if modifying the header part of the cloned buffer
  *      does not requires the data to be copied.
  */
-static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
+static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
 {
         return !skb_header_cloned(skb) &&
                skb_headroom(skb) + len <= skb->hdr_len;
@@ -2451,7 +2451,8 @@ static inline bool skb_warn_if_lro(const struct sk_buff *skb)
 {
         /* LRO sets gso_size but not gso_type, whereas if GSO is really
          * wanted then gso_type will be set. */
-        struct skb_shared_info *shinfo = skb_shinfo(skb);
+        const struct skb_shared_info *shinfo = skb_shinfo(skb);
+
         if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
             unlikely(shinfo->gso_type == 0)) {
                 __skb_warn_lro_forwarding(skb);
@@ -2475,7 +2476,7 @@ static inline void skb_forward_csum(struct sk_buff *skb)
  * Instead of forcing ip_summed to CHECKSUM_NONE, we can
  * use this helper, to document places where we make this assertion.
  */
-static inline void skb_checksum_none_assert(struct sk_buff *skb)
+static inline void skb_checksum_none_assert(const struct sk_buff *skb)
 {
 #ifdef DEBUG
         BUG_ON(skb->ip_summed != CHECKSUM_NONE);
@@ -2484,7 +2485,7 @@ static inline void skb_checksum_none_assert(struct sk_buff *skb)
 
 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
 
-static inline bool skb_is_recycleable(struct sk_buff *skb, int skb_size)
+static inline bool skb_is_recycleable(const struct sk_buff *skb, int skb_size)
 {
         if (irqs_disabled())
                 return false;
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 4fc88f3ccd5f..2eb207ea4eaf 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -46,14 +46,14 @@ struct qdisc_size_table {
 struct Qdisc {
         int                     (*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
         struct sk_buff *        (*dequeue)(struct Qdisc *dev);
-        unsigned                flags;
+        unsigned int            flags;
 #define TCQ_F_BUILTIN           1
 #define TCQ_F_INGRESS           2
 #define TCQ_F_CAN_BYPASS        4
 #define TCQ_F_MQROOT            8
 #define TCQ_F_WARN_NONWC        (1 << 16)
         int                     padded;
-        struct Qdisc_ops        *ops;
+        const struct Qdisc_ops  *ops;
         struct qdisc_size_table __rcu *stab;
         struct list_head        list;
         u32                     handle;
@@ -224,7 +224,7 @@ struct qdisc_skb_cb {
         long                    data[];
 };
 
-static inline int qdisc_qlen(struct Qdisc *q)
+static inline int qdisc_qlen(const struct Qdisc *q)
 {
         return q->q.qlen;
 }
@@ -239,12 +239,12 @@ static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
         return &qdisc->q.lock;
 }
 
-static inline struct Qdisc *qdisc_root(struct Qdisc *qdisc)
+static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
 {
         return qdisc->dev_queue->qdisc;
 }
 
-static inline struct Qdisc *qdisc_root_sleeping(struct Qdisc *qdisc)
+static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
 {
         return qdisc->dev_queue->qdisc_sleeping;
 }
@@ -260,7 +260,7 @@ static inline struct Qdisc *qdisc_root_sleeping(struct Qdisc *qdisc)
  * root.  This is enforced by holding the RTNL semaphore, which
  * all users of this lock accessor must do.
  */
-static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc)
+static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
 {
         struct Qdisc *root = qdisc_root(qdisc);
 
@@ -268,7 +268,7 @@ static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc)
         return qdisc_lock(root);
 }
 
-static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc)
+static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
 {
         struct Qdisc *root = qdisc_root_sleeping(qdisc);
 
@@ -276,17 +276,17 @@ static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc)
         return qdisc_lock(root);
 }
 
-static inline struct net_device *qdisc_dev(struct Qdisc *qdisc)
+static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
 {
         return qdisc->dev_queue->dev;
 }
 
-static inline void sch_tree_lock(struct Qdisc *q)
+static inline void sch_tree_lock(const struct Qdisc *q)
 {
         spin_lock_bh(qdisc_root_sleeping_lock(q));
 }
 
-static inline void sch_tree_unlock(struct Qdisc *q)
+static inline void sch_tree_unlock(const struct Qdisc *q)
 {
         spin_unlock_bh(qdisc_root_sleeping_lock(q));
 }
@@ -319,7 +319,7 @@ static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
 }
 
 static inline struct Qdisc_class_common *
-qdisc_class_find(struct Qdisc_class_hash *hash, u32 id)
+qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
 {
         struct Qdisc_class_common *cl;
         struct hlist_node *n;
@@ -393,7 +393,7 @@ static inline bool qdisc_all_tx_empty(const struct net_device *dev)
 }
 
 /* Are any of the TX qdiscs changing?  */
-static inline bool qdisc_tx_changing(struct net_device *dev)
+static inline bool qdisc_tx_changing(const struct net_device *dev)
 {
         unsigned int i;
         for (i = 0; i < dev->num_tx_queues; i++) {