linux-stable/net/sctp/stream_sched_prio.c
Xin Long 1ba896f6f5 sctp: remove extern from stream sched
Now each stream sched ops is defined in different .c file and
added into the global ops in another .c file, it uses extern
to make this work.

However extern is not good coding style to get them in and
even make C=2 reports errors for this.

This patch adds sctp_sched_ops_xxx_init for each stream sched
ops in their .c file, then get them into the global ops by
calling them when initializing sctp module.

Fixes: 637784ade2 ("sctp: introduce priority based stream scheduler")
Fixes: ac1ed8b82c ("sctp: introduce round robin stream scheduler")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-28 11:00:13 -05:00

352 lines
9 KiB
C

/* SCTP kernel implementation
* (C) Copyright Red Hat Inc. 2017
*
* This file is part of the SCTP kernel implementation
*
* These functions manipulate sctp stream queue/scheduling.
*
* This SCTP implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*
* Please send any bug reports or fixes you make to the
* email addresched(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* Written or modified by:
* Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
*/
#include <linux/list.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
#include <net/sctp/stream_sched.h>
/* Priority handling
* RFC DRAFT ndata section 3.4
*/
static void sctp_sched_prio_unsched_all(struct sctp_stream *stream);
static struct sctp_stream_priorities *sctp_sched_prio_new_head(
struct sctp_stream *stream, int prio, gfp_t gfp)
{
struct sctp_stream_priorities *p;
p = kmalloc(sizeof(*p), gfp);
if (!p)
return NULL;
INIT_LIST_HEAD(&p->prio_sched);
INIT_LIST_HEAD(&p->active);
p->next = NULL;
p->prio = prio;
return p;
}
static struct sctp_stream_priorities *sctp_sched_prio_get_head(
struct sctp_stream *stream, int prio, gfp_t gfp)
{
struct sctp_stream_priorities *p;
int i;
/* Look into scheduled priorities first, as they are sorted and
* we can find it fast IF it's scheduled.
*/
list_for_each_entry(p, &stream->prio_list, prio_sched) {
if (p->prio == prio)
return p;
if (p->prio > prio)
break;
}
/* No luck. So we search on all streams now. */
for (i = 0; i < stream->outcnt; i++) {
if (!stream->out[i].ext)
continue;
p = stream->out[i].ext->prio_head;
if (!p)
/* Means all other streams won't be initialized
* as well.
*/
break;
if (p->prio == prio)
return p;
}
/* If not even there, allocate a new one. */
return sctp_sched_prio_new_head(stream, prio, gfp);
}
static void sctp_sched_prio_next_stream(struct sctp_stream_priorities *p)
{
struct list_head *pos;
pos = p->next->prio_list.next;
if (pos == &p->active)
pos = pos->next;
p->next = list_entry(pos, struct sctp_stream_out_ext, prio_list);
}
static bool sctp_sched_prio_unsched(struct sctp_stream_out_ext *soute)
{
bool scheduled = false;
if (!list_empty(&soute->prio_list)) {
struct sctp_stream_priorities *prio_head = soute->prio_head;
/* Scheduled */
scheduled = true;
if (prio_head->next == soute)
/* Try to move to the next stream */
sctp_sched_prio_next_stream(prio_head);
list_del_init(&soute->prio_list);
/* Also unsched the priority if this was the last stream */
if (list_empty(&prio_head->active)) {
list_del_init(&prio_head->prio_sched);
/* If there is no stream left, clear next */
prio_head->next = NULL;
}
}
return scheduled;
}
static void sctp_sched_prio_sched(struct sctp_stream *stream,
struct sctp_stream_out_ext *soute)
{
struct sctp_stream_priorities *prio, *prio_head;
prio_head = soute->prio_head;
/* Nothing to do if already scheduled */
if (!list_empty(&soute->prio_list))
return;
/* Schedule the stream. If there is a next, we schedule the new
* one before it, so it's the last in round robin order.
* If there isn't, we also have to schedule the priority.
*/
if (prio_head->next) {
list_add(&soute->prio_list, prio_head->next->prio_list.prev);
return;
}
list_add(&soute->prio_list, &prio_head->active);
prio_head->next = soute;
list_for_each_entry(prio, &stream->prio_list, prio_sched) {
if (prio->prio > prio_head->prio) {
list_add(&prio_head->prio_sched, prio->prio_sched.prev);
return;
}
}
list_add_tail(&prio_head->prio_sched, &stream->prio_list);
}
static int sctp_sched_prio_set(struct sctp_stream *stream, __u16 sid,
__u16 prio, gfp_t gfp)
{
struct sctp_stream_out *sout = &stream->out[sid];
struct sctp_stream_out_ext *soute = sout->ext;
struct sctp_stream_priorities *prio_head, *old;
bool reschedule = false;
int i;
prio_head = sctp_sched_prio_get_head(stream, prio, gfp);
if (!prio_head)
return -ENOMEM;
reschedule = sctp_sched_prio_unsched(soute);
old = soute->prio_head;
soute->prio_head = prio_head;
if (reschedule)
sctp_sched_prio_sched(stream, soute);
if (!old)
/* Happens when we set the priority for the first time */
return 0;
for (i = 0; i < stream->outcnt; i++) {
soute = stream->out[i].ext;
if (soute && soute->prio_head == old)
/* It's still in use, nothing else to do here. */
return 0;
}
/* No hits, we are good to free it. */
kfree(old);
return 0;
}
static int sctp_sched_prio_get(struct sctp_stream *stream, __u16 sid,
__u16 *value)
{
*value = stream->out[sid].ext->prio_head->prio;
return 0;
}
static int sctp_sched_prio_init(struct sctp_stream *stream)
{
INIT_LIST_HEAD(&stream->prio_list);
return 0;
}
static int sctp_sched_prio_init_sid(struct sctp_stream *stream, __u16 sid,
gfp_t gfp)
{
INIT_LIST_HEAD(&stream->out[sid].ext->prio_list);
return sctp_sched_prio_set(stream, sid, 0, gfp);
}
static void sctp_sched_prio_free(struct sctp_stream *stream)
{
struct sctp_stream_priorities *prio, *n;
LIST_HEAD(list);
int i;
/* As we don't keep a list of priorities, to avoid multiple
* frees we have to do it in 3 steps:
* 1. unsched everyone, so the lists are free to use in 2.
* 2. build the list of the priorities
* 3. free the list
*/
sctp_sched_prio_unsched_all(stream);
for (i = 0; i < stream->outcnt; i++) {
if (!stream->out[i].ext)
continue;
prio = stream->out[i].ext->prio_head;
if (prio && list_empty(&prio->prio_sched))
list_add(&prio->prio_sched, &list);
}
list_for_each_entry_safe(prio, n, &list, prio_sched) {
list_del_init(&prio->prio_sched);
kfree(prio);
}
}
static void sctp_sched_prio_enqueue(struct sctp_outq *q,
struct sctp_datamsg *msg)
{
struct sctp_stream *stream;
struct sctp_chunk *ch;
__u16 sid;
ch = list_first_entry(&msg->chunks, struct sctp_chunk, frag_list);
sid = sctp_chunk_stream_no(ch);
stream = &q->asoc->stream;
sctp_sched_prio_sched(stream, stream->out[sid].ext);
}
static struct sctp_chunk *sctp_sched_prio_dequeue(struct sctp_outq *q)
{
struct sctp_stream *stream = &q->asoc->stream;
struct sctp_stream_priorities *prio;
struct sctp_stream_out_ext *soute;
struct sctp_chunk *ch = NULL;
/* Bail out quickly if queue is empty */
if (list_empty(&q->out_chunk_list))
goto out;
/* Find which chunk is next. It's easy, it's either the current
* one or the first chunk on the next active stream.
*/
if (stream->out_curr) {
soute = stream->out_curr->ext;
} else {
prio = list_entry(stream->prio_list.next,
struct sctp_stream_priorities, prio_sched);
soute = prio->next;
}
ch = list_entry(soute->outq.next, struct sctp_chunk, stream_list);
sctp_sched_dequeue_common(q, ch);
out:
return ch;
}
static void sctp_sched_prio_dequeue_done(struct sctp_outq *q,
struct sctp_chunk *ch)
{
struct sctp_stream_priorities *prio;
struct sctp_stream_out_ext *soute;
__u16 sid;
/* Last chunk on that msg, move to the next stream on
* this priority.
*/
sid = sctp_chunk_stream_no(ch);
soute = q->asoc->stream.out[sid].ext;
prio = soute->prio_head;
sctp_sched_prio_next_stream(prio);
if (list_empty(&soute->outq))
sctp_sched_prio_unsched(soute);
}
static void sctp_sched_prio_sched_all(struct sctp_stream *stream)
{
struct sctp_association *asoc;
struct sctp_stream_out *sout;
struct sctp_chunk *ch;
asoc = container_of(stream, struct sctp_association, stream);
list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
__u16 sid;
sid = sctp_chunk_stream_no(ch);
sout = &stream->out[sid];
if (sout->ext)
sctp_sched_prio_sched(stream, sout->ext);
}
}
static void sctp_sched_prio_unsched_all(struct sctp_stream *stream)
{
struct sctp_stream_priorities *p, *tmp;
struct sctp_stream_out_ext *soute, *souttmp;
list_for_each_entry_safe(p, tmp, &stream->prio_list, prio_sched)
list_for_each_entry_safe(soute, souttmp, &p->active, prio_list)
sctp_sched_prio_unsched(soute);
}
static struct sctp_sched_ops sctp_sched_prio = {
.set = sctp_sched_prio_set,
.get = sctp_sched_prio_get,
.init = sctp_sched_prio_init,
.init_sid = sctp_sched_prio_init_sid,
.free = sctp_sched_prio_free,
.enqueue = sctp_sched_prio_enqueue,
.dequeue = sctp_sched_prio_dequeue,
.dequeue_done = sctp_sched_prio_dequeue_done,
.sched_all = sctp_sched_prio_sched_all,
.unsched_all = sctp_sched_prio_unsched_all,
};
void sctp_sched_ops_prio_init(void)
{
sctp_sched_ops_register(SCTP_SS_PRIO, &sctp_sched_prio);
}