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[TCP]: Abstract out all write queue operations.
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This allows the write queue implementation to be changed,
for example, to one which allows fast interval searching.

Signed-off-by: David S. Miller <[email protected]>
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David S. Miller committed Apr 26, 2007
1 parent 02ea492 commit fe067e8
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Showing 7 changed files with 221 additions and 117 deletions.
21 changes: 0 additions & 21 deletions include/net/sock.h
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Original file line number Diff line number Diff line change
Expand Up @@ -710,15 +710,6 @@ static inline void sk_stream_mem_reclaim(struct sock *sk)
__sk_stream_mem_reclaim(sk);
}

static inline void sk_stream_writequeue_purge(struct sock *sk)
{
struct sk_buff *skb;

while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
sk_stream_free_skb(sk, skb);
sk_stream_mem_reclaim(sk);
}

static inline int sk_stream_rmem_schedule(struct sock *sk, struct sk_buff *skb)
{
return (int)skb->truesize <= sk->sk_forward_alloc ||
Expand Down Expand Up @@ -1256,18 +1247,6 @@ static inline struct page *sk_stream_alloc_page(struct sock *sk)
return page;
}

#define sk_stream_for_retrans_queue(skb, sk) \
for (skb = (sk)->sk_write_queue.next; \
(skb != (sk)->sk_send_head) && \
(skb != (struct sk_buff *)&(sk)->sk_write_queue); \
skb = skb->next)

/*from STCP for fast SACK Process*/
#define sk_stream_for_retrans_queue_from(skb, sk) \
for (; (skb != (sk)->sk_send_head) && \
(skb != (struct sk_buff *)&(sk)->sk_write_queue); \
skb = skb->next)

/*
* Default write policy as shown to user space via poll/select/SIGIO
*/
Expand Down
114 changes: 114 additions & 0 deletions include/net/tcp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1162,6 +1162,120 @@ static inline void tcp_put_md5sig_pool(void)
put_cpu();
}

/* write queue abstraction */
static inline void tcp_write_queue_purge(struct sock *sk)
{
struct sk_buff *skb;

while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
sk_stream_free_skb(sk, skb);
sk_stream_mem_reclaim(sk);
}

static inline struct sk_buff *tcp_write_queue_head(struct sock *sk)
{
struct sk_buff *skb = sk->sk_write_queue.next;
if (skb == (struct sk_buff *) &sk->sk_write_queue)
return NULL;
return skb;
}

static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk)
{
struct sk_buff *skb = sk->sk_write_queue.prev;
if (skb == (struct sk_buff *) &sk->sk_write_queue)
return NULL;
return skb;
}

static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb)
{
return skb->next;
}

#define tcp_for_write_queue(skb, sk) \
for (skb = (sk)->sk_write_queue.next; \
(skb != (struct sk_buff *)&(sk)->sk_write_queue); \
skb = skb->next)

#define tcp_for_write_queue_from(skb, sk) \
for (; (skb != (struct sk_buff *)&(sk)->sk_write_queue);\
skb = skb->next)

static inline struct sk_buff *tcp_send_head(struct sock *sk)
{
return sk->sk_send_head;
}

static inline void tcp_advance_send_head(struct sock *sk, struct sk_buff *skb)
{
sk->sk_send_head = skb->next;
if (sk->sk_send_head == (struct sk_buff *)&sk->sk_write_queue)
sk->sk_send_head = NULL;
}

static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked)
{
if (sk->sk_send_head == skb_unlinked)
sk->sk_send_head = NULL;
}

static inline void tcp_init_send_head(struct sock *sk)
{
sk->sk_send_head = NULL;
}

static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
{
__skb_queue_tail(&sk->sk_write_queue, skb);
}

static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
{
__tcp_add_write_queue_tail(sk, skb);

/* Queue it, remembering where we must start sending. */
if (sk->sk_send_head == NULL)
sk->sk_send_head = skb;
}

static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb)
{
__skb_queue_head(&sk->sk_write_queue, skb);
}

/* Insert buff after skb on the write queue of sk. */
static inline void tcp_insert_write_queue_after(struct sk_buff *skb,
struct sk_buff *buff,
struct sock *sk)
{
__skb_append(skb, buff, &sk->sk_write_queue);
}

/* Insert skb between prev and next on the write queue of sk. */
static inline void tcp_insert_write_queue_before(struct sk_buff *new,
struct sk_buff *skb,
struct sock *sk)
{
__skb_insert(new, skb->prev, skb, &sk->sk_write_queue);
}

static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk)
{
__skb_unlink(skb, &sk->sk_write_queue);
}

static inline int tcp_skb_is_last(const struct sock *sk,
const struct sk_buff *skb)
{
return skb->next == (struct sk_buff *)&sk->sk_write_queue;
}

static inline int tcp_write_queue_empty(struct sock *sk)
{
return skb_queue_empty(&sk->sk_write_queue);
}

/* /proc */
enum tcp_seq_states {
TCP_SEQ_STATE_LISTENING,
Expand Down
32 changes: 16 additions & 16 deletions net/ipv4/tcp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -470,10 +470,8 @@ static inline void skb_entail(struct sock *sk, struct tcp_sock *tp,
tcb->flags = TCPCB_FLAG_ACK;
tcb->sacked = 0;
skb_header_release(skb);
__skb_queue_tail(&sk->sk_write_queue, skb);
tcp_add_write_queue_tail(sk, skb);
sk_charge_skb(sk, skb);
if (!sk->sk_send_head)
sk->sk_send_head = skb;
if (tp->nonagle & TCP_NAGLE_PUSH)
tp->nonagle &= ~TCP_NAGLE_PUSH;
}
Expand All @@ -491,8 +489,8 @@ static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
static inline void tcp_push(struct sock *sk, struct tcp_sock *tp, int flags,
int mss_now, int nonagle)
{
if (sk->sk_send_head) {
struct sk_buff *skb = sk->sk_write_queue.prev;
if (tcp_send_head(sk)) {
struct sk_buff *skb = tcp_write_queue_tail(sk);
if (!(flags & MSG_MORE) || forced_push(tp))
tcp_mark_push(tp, skb);
tcp_mark_urg(tp, flags, skb);
Expand Down Expand Up @@ -526,13 +524,13 @@ static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffse
goto do_error;

while (psize > 0) {
struct sk_buff *skb = sk->sk_write_queue.prev;
struct sk_buff *skb = tcp_write_queue_tail(sk);
struct page *page = pages[poffset / PAGE_SIZE];
int copy, i, can_coalesce;
int offset = poffset % PAGE_SIZE;
int size = min_t(size_t, psize, PAGE_SIZE - offset);

if (!sk->sk_send_head || (copy = size_goal - skb->len) <= 0) {
if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
new_segment:
if (!sk_stream_memory_free(sk))
goto wait_for_sndbuf;
Expand Down Expand Up @@ -589,7 +587,7 @@ static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffse
if (forced_push(tp)) {
tcp_mark_push(tp, skb);
__tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_PUSH);
} else if (skb == sk->sk_send_head)
} else if (skb == tcp_send_head(sk))
tcp_push_one(sk, mss_now);
continue;

Expand Down Expand Up @@ -704,9 +702,9 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
while (seglen > 0) {
int copy;

skb = sk->sk_write_queue.prev;
skb = tcp_write_queue_tail(sk);

if (!sk->sk_send_head ||
if (!tcp_send_head(sk) ||
(copy = size_goal - skb->len) <= 0) {

new_segment:
Expand Down Expand Up @@ -833,7 +831,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
if (forced_push(tp)) {
tcp_mark_push(tp, skb);
__tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_PUSH);
} else if (skb == sk->sk_send_head)
} else if (skb == tcp_send_head(sk))
tcp_push_one(sk, mss_now);
continue;

Expand All @@ -860,9 +858,11 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,

do_fault:
if (!skb->len) {
if (sk->sk_send_head == skb)
sk->sk_send_head = NULL;
__skb_unlink(skb, &sk->sk_write_queue);
tcp_unlink_write_queue(skb, sk);
/* It is the one place in all of TCP, except connection
* reset, where we can be unlinking the send_head.
*/
tcp_check_send_head(sk, skb);
sk_stream_free_skb(sk, skb);
}

Expand Down Expand Up @@ -1732,7 +1732,7 @@ int tcp_disconnect(struct sock *sk, int flags)

tcp_clear_xmit_timers(sk);
__skb_queue_purge(&sk->sk_receive_queue);
sk_stream_writequeue_purge(sk);
tcp_write_queue_purge(sk);
__skb_queue_purge(&tp->out_of_order_queue);
#ifdef CONFIG_NET_DMA
__skb_queue_purge(&sk->sk_async_wait_queue);
Expand All @@ -1758,7 +1758,7 @@ int tcp_disconnect(struct sock *sk, int flags)
tcp_set_ca_state(sk, TCP_CA_Open);
tcp_clear_retrans(tp);
inet_csk_delack_init(sk);
sk->sk_send_head = NULL;
tcp_init_send_head(sk);
tp->rx_opt.saw_tstamp = 0;
tcp_sack_reset(&tp->rx_opt);
__sk_dst_reset(sk);
Expand Down
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