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sctp: move flushing of data chunks out of sctp_outq_flush
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To the new sctp_outq_flush_data. Again, smaller functions and with well
defined objectives.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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@marceloleitner @davem330
marceloleitner authored and davem330 committed May 15, 2018
1 parent 96e0418 commit cb93cc5
Showing 1 changed file with 75 additions and 74 deletions.
149 changes: 75 additions & 74 deletions net/sctp/outqueue.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1038,46 +1038,17 @@ static bool sctp_outq_flush_rtx(struct sctp_outq *q,

return true;
}
/*
* Try to flush an outqueue.
*
* Description: Send everything in q which we legally can, subject to
* congestion limitations.
* * Note: This function can be called from multiple contexts so appropriate
* locking concerns must be made. Today we use the sock lock to protect
* this function.
*/
static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)

static void sctp_outq_flush_data(struct sctp_outq *q,
struct sctp_transport **_transport,
struct list_head *transport_list,
int rtx_timeout, gfp_t gfp)
{
struct sctp_packet *packet;
struct sctp_transport *transport = *_transport;
struct sctp_packet *packet = transport ? &transport->packet : NULL;
struct sctp_association *asoc = q->asoc;
struct sctp_transport *transport = NULL;
struct sctp_chunk *chunk;
enum sctp_xmit status;
int error = 0;

/* These transports have chunks to send. */
struct list_head transport_list;
struct list_head *ltransport;

INIT_LIST_HEAD(&transport_list);
packet = NULL;

/*
* 6.10 Bundling
* ...
* When bundling control chunks with DATA chunks, an
* endpoint MUST place control chunks first in the outbound
* SCTP packet. The transmitter MUST transmit DATA chunks
* within a SCTP packet in increasing order of TSN.
* ...
*/

sctp_outq_flush_ctrl(q, &transport, &transport_list, gfp);
packet = &transport->packet;

if (q->asoc->src_out_of_asoc_ok)
goto sctp_flush_out;

/* Is it OK to send data chunks? */
switch (asoc->state) {
Expand All @@ -1102,10 +1073,11 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
* current cwnd).
*/
if (!list_empty(&q->retransmit)) {
if (!sctp_outq_flush_rtx(q, &transport, &transport_list,
if (!sctp_outq_flush_rtx(q, _transport, transport_list,
rtx_timeout))
break;
/* We may have switched current transport */
transport = *_transport;
packet = &transport->packet;
}

Expand All @@ -1131,12 +1103,14 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)

if (asoc->stream.out[sid].state == SCTP_STREAM_CLOSED) {
sctp_outq_head_data(q, chunk);
goto sctp_flush_out;
break;
}

if (sctp_outq_select_transport(chunk, asoc, &transport,
&transport_list))
if (sctp_outq_select_transport(chunk, asoc, _transport,
transport_list)) {
transport = *_transport;
packet = &transport->packet;
}

pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p "
"skb->users:%d\n",
Expand All @@ -1148,8 +1122,10 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)

/* Add the chunk to the packet. */
status = sctp_packet_transmit_chunk(packet, chunk, 0, gfp);

switch (status) {
case SCTP_XMIT_OK:
break;

case SCTP_XMIT_PMTU_FULL:
case SCTP_XMIT_RWND_FULL:
case SCTP_XMIT_DELAY:
Expand All @@ -1161,41 +1137,25 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
status);

sctp_outq_head_data(q, chunk);
goto sctp_flush_out;

case SCTP_XMIT_OK:
/* The sender is in the SHUTDOWN-PENDING state,
* The sender MAY set the I-bit in the DATA
* chunk header.
*/
if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
asoc->stats.ouodchunks++;
else
asoc->stats.oodchunks++;

/* Only now it's safe to consider this
* chunk as sent, sched-wise.
*/
sctp_sched_dequeue_done(q, chunk);

break;

default:
BUG();
return;
}

/* BUG: We assume that the sctp_packet_transmit()
* call below will succeed all the time and add the
* chunk to the transmitted list and restart the
* timers.
* It is possible that the call can fail under OOM
* conditions.
*
* Is this really a problem? Won't this behave
* like a lost TSN?
/* The sender is in the SHUTDOWN-PENDING state,
* The sender MAY set the I-bit in the DATA
* chunk header.
*/
if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
asoc->stats.ouodchunks++;
else
asoc->stats.oodchunks++;

/* Only now it's safe to consider this
* chunk as sent, sched-wise.
*/
sctp_sched_dequeue_done(q, chunk);

list_add_tail(&chunk->transmitted_list,
&transport->transmitted);

Expand All @@ -1206,14 +1166,55 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
* COOKIE-ECHO chunk.
*/
if (packet->has_cookie_echo)
goto sctp_flush_out;
break;
}
break;

default:
/* Do nothing. */
break;
}
}

/*
* Try to flush an outqueue.
*
* Description: Send everything in q which we legally can, subject to
* congestion limitations.
* * Note: This function can be called from multiple contexts so appropriate
* locking concerns must be made. Today we use the sock lock to protect
* this function.
*/
static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
{
struct sctp_packet *packet;
struct sctp_association *asoc = q->asoc;
struct sctp_transport *transport = NULL;
int error = 0;

/* These transports have chunks to send. */
struct list_head transport_list;
struct list_head *ltransport;

INIT_LIST_HEAD(&transport_list);
packet = NULL;

/*
* 6.10 Bundling
* ...
* When bundling control chunks with DATA chunks, an
* endpoint MUST place control chunks first in the outbound
* SCTP packet. The transmitter MUST transmit DATA chunks
* within a SCTP packet in increasing order of TSN.
* ...
*/

sctp_outq_flush_ctrl(q, &transport, &transport_list, gfp);

if (q->asoc->src_out_of_asoc_ok)
goto sctp_flush_out;

sctp_outq_flush_data(q, &transport, &transport_list, rtx_timeout, gfp);

sctp_flush_out:

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