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[TIMEWAIT]: Move inet_timewait_death_row routines to net/ipv4/inet_timewait_sock.c

Browse source 
Also export the ones that will be used in the next changeset, when
DCCP uses this infrastructure.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnaldo Carvalho de Melo 2005-08-09 20:45:03 -07:00 committed by David S. Miller
parent 295ff7edb8
commit 696ab2d3bf
4 changed files with 290 additions and 273 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
include/net/inet_timewait_sock.h
View file

@ -82,6 +82,10 @@ struct inet_timewait_death_row {
int sysctl_max_tw_buckets;
};
extern void inet_twdr_hangman(unsigned long data);
extern void inet_twdr_twkill_work(void *data);
extern void inet_twdr_twcal_tick(unsigned long data);
#if (BITS_PER_LONG == 64)
#define INET_TIMEWAIT_ADDRCMP_ALIGN_BYTES 8
#else
@ -206,4 +210,10 @@ extern void __inet_twsk_kill(struct inet_timewait_sock *tw,
extern void __inet_twsk_hashdance(struct inet_timewait_sock *tw,
struct sock *sk,
struct inet_hashinfo *hashinfo);
extern void inet_twsk_schedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr,
const int timeo, const int timewait_len);
extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr);
#endif /* _INET_TIMEWAIT_SOCK_ */

2
include/net/tcp.h
View file

@ -44,8 +44,6 @@ extern struct inet_hashinfo tcp_hashinfo;
extern atomic_t tcp_orphan_count;
extern void tcp_time_wait(struct sock *sk, int state, int timeo);
extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr);
#define MAX_TCP_HEADER (128 + MAX_HEADER)

270
net/ipv4/inet_timewait_sock.c
View file

@ -12,6 +12,7 @@
#include <net/inet_hashtables.h>
#include <net/inet_timewait_sock.h>
#include <net/ip.h>
/* Must be called with locally disabled BHs. */
void __inet_twsk_kill(struct inet_timewait_sock *tw, struct inet_hashinfo *hashinfo)
@ -85,6 +86,8 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
write_unlock(&ehead->lock);
}
EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int state)
{
struct inet_timewait_sock *tw = kmem_cache_alloc(sk->sk_prot_creator->twsk_slab,
@ -112,3 +115,270 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
return tw;
}
EXPORT_SYMBOL_GPL(inet_twsk_alloc);
/* Returns non-zero if quota exceeded. */
static int inet_twdr_do_twkill_work(struct inet_timewait_death_row *twdr,
const int slot)
{
struct inet_timewait_sock *tw;
struct hlist_node *node;
unsigned int killed;
int ret;
/* NOTE: compare this to previous version where lock
* was released after detaching chain. It was racy,
* because tw buckets are scheduled in not serialized context
* in 2.3 (with netfilter), and with softnet it is common, because
* soft irqs are not sequenced.
*/
killed = 0;
ret = 0;
rescan:
inet_twsk_for_each_inmate(tw, node, &twdr->cells[slot]) {
__inet_twsk_del_dead_node(tw);
spin_unlock(&twdr->death_lock);
__inet_twsk_kill(tw, twdr->hashinfo);
inet_twsk_put(tw);
killed++;
spin_lock(&twdr->death_lock);
if (killed > INET_TWDR_TWKILL_QUOTA) {
ret = 1;
break;
}
/* While we dropped twdr->death_lock, another cpu may have
* killed off the next TW bucket in the list, therefore
* do a fresh re-read of the hlist head node with the
* lock reacquired. We still use the hlist traversal
* macro in order to get the prefetches.
*/
goto rescan;
}
twdr->tw_count -= killed;
NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITED, killed);
return ret;
}
void inet_twdr_hangman(unsigned long data)
{
struct inet_timewait_death_row *twdr;
int unsigned need_timer;
twdr = (struct inet_timewait_death_row *)data;
spin_lock(&twdr->death_lock);
if (twdr->tw_count == 0)
goto out;
need_timer = 0;
if (inet_twdr_do_twkill_work(twdr, twdr->slot)) {
twdr->thread_slots |= (1 << twdr->slot);
mb();
schedule_work(&twdr->twkill_work);
need_timer = 1;
} else {
/* We purged the entire slot, anything left? */
if (twdr->tw_count)
need_timer = 1;
}
twdr->slot = ((twdr->slot + 1) & (INET_TWDR_TWKILL_SLOTS - 1));
if (need_timer)
mod_timer(&twdr->tw_timer, jiffies + twdr->period);
out:
spin_unlock(&twdr->death_lock);
}
EXPORT_SYMBOL_GPL(inet_twdr_hangman);
extern void twkill_slots_invalid(void);
void inet_twdr_twkill_work(void *data)
{
struct inet_timewait_death_row *twdr = data;
int i;
if ((INET_TWDR_TWKILL_SLOTS - 1) > (sizeof(twdr->thread_slots) * 8))
twkill_slots_invalid();
while (twdr->thread_slots) {
spin_lock_bh(&twdr->death_lock);
for (i = 0; i < INET_TWDR_TWKILL_SLOTS; i++) {
if (!(twdr->thread_slots & (1 << i)))
continue;
while (inet_twdr_do_twkill_work(twdr, i) != 0) {
if (need_resched()) {
spin_unlock_bh(&twdr->death_lock);
schedule();
spin_lock_bh(&twdr->death_lock);
}
}
twdr->thread_slots &= ~(1 << i);
}
spin_unlock_bh(&twdr->death_lock);
}
}
EXPORT_SYMBOL_GPL(inet_twdr_twkill_work);
/* These are always called from BH context. See callers in
* tcp_input.c to verify this.
*/
/* This is for handling early-kills of TIME_WAIT sockets. */
void inet_twsk_deschedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr)
{
spin_lock(&twdr->death_lock);
if (inet_twsk_del_dead_node(tw)) {
inet_twsk_put(tw);
if (--twdr->tw_count == 0)
del_timer(&twdr->tw_timer);
}
spin_unlock(&twdr->death_lock);
__inet_twsk_kill(tw, twdr->hashinfo);
}
EXPORT_SYMBOL(inet_twsk_deschedule);
void inet_twsk_schedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr,
const int timeo, const int timewait_len)
{
struct hlist_head *list;
int slot;
/* timeout := RTO * 3.5
*
* 3.5 = 1+2+0.5 to wait for two retransmits.
*
* RATIONALE: if FIN arrived and we entered TIME-WAIT state,
* our ACK acking that FIN can be lost. If N subsequent retransmitted
* FINs (or previous seqments) are lost (probability of such event
* is p^(N+1), where p is probability to lose single packet and
* time to detect the loss is about RTO*(2^N - 1) with exponential
* backoff). Normal timewait length is calculated so, that we
* waited at least for one retransmitted FIN (maximal RTO is 120sec).
* [ BTW Linux. following BSD, violates this requirement waiting
* only for 60sec, we should wait at least for 240 secs.
* Well, 240 consumes too much of resources 8)
* ]
* This interval is not reduced to catch old duplicate and
* responces to our wandering segments living for two MSLs.
* However, if we use PAWS to detect
* old duplicates, we can reduce the interval to bounds required
* by RTO, rather than MSL. So, if peer understands PAWS, we
* kill tw bucket after 3.5*RTO (it is important that this number
* is greater than TS tick!) and detect old duplicates with help
* of PAWS.
*/
slot = (timeo + (1 << INET_TWDR_RECYCLE_TICK) - 1) >> INET_TWDR_RECYCLE_TICK;
spin_lock(&twdr->death_lock);
/* Unlink it, if it was scheduled */
if (inet_twsk_del_dead_node(tw))
twdr->tw_count--;
else
atomic_inc(&tw->tw_refcnt);
if (slot >= INET_TWDR_RECYCLE_SLOTS) {
/* Schedule to slow timer */
if (timeo >= timewait_len) {
slot = INET_TWDR_TWKILL_SLOTS - 1;
} else {
slot = (timeo + twdr->period - 1) / twdr->period;
if (slot >= INET_TWDR_TWKILL_SLOTS)
slot = INET_TWDR_TWKILL_SLOTS - 1;
}
tw->tw_ttd = jiffies + timeo;
slot = (twdr->slot + slot) & (INET_TWDR_TWKILL_SLOTS - 1);
list = &twdr->cells[slot];
} else {
tw->tw_ttd = jiffies + (slot << INET_TWDR_RECYCLE_TICK);
if (twdr->twcal_hand < 0) {
twdr->twcal_hand = 0;
twdr->twcal_jiffie = jiffies;
twdr->twcal_timer.expires = twdr->twcal_jiffie +
(slot << INET_TWDR_RECYCLE_TICK);
add_timer(&twdr->twcal_timer);
} else {
if (time_after(twdr->twcal_timer.expires,
jiffies + (slot << INET_TWDR_RECYCLE_TICK)))
mod_timer(&twdr->twcal_timer,
jiffies + (slot << INET_TWDR_RECYCLE_TICK));
slot = (twdr->twcal_hand + slot) & (INET_TWDR_RECYCLE_SLOTS - 1);
}
list = &twdr->twcal_row[slot];
}
hlist_add_head(&tw->tw_death_node, list);
if (twdr->tw_count++ == 0)
mod_timer(&twdr->tw_timer, jiffies + twdr->period);
spin_unlock(&twdr->death_lock);
}
EXPORT_SYMBOL_GPL(inet_twsk_schedule);
void inet_twdr_twcal_tick(unsigned long data)
{
struct inet_timewait_death_row *twdr;
int n, slot;
unsigned long j;
unsigned long now = jiffies;
int killed = 0;
int adv = 0;
twdr = (struct inet_timewait_death_row *)data;
spin_lock(&twdr->death_lock);
if (twdr->twcal_hand < 0)
goto out;
slot = twdr->twcal_hand;
j = twdr->twcal_jiffie;
for (n = 0; n < INET_TWDR_RECYCLE_SLOTS; n++) {
if (time_before_eq(j, now)) {
struct hlist_node *node, *safe;
struct inet_timewait_sock *tw;
inet_twsk_for_each_inmate_safe(tw, node, safe,
&twdr->twcal_row[slot]) {
__inet_twsk_del_dead_node(tw);
__inet_twsk_kill(tw, twdr->hashinfo);
inet_twsk_put(tw);
killed++;
}
} else {
if (!adv) {
adv = 1;
twdr->twcal_jiffie = j;
twdr->twcal_hand = slot;
}
if (!hlist_empty(&twdr->twcal_row[slot])) {
mod_timer(&twdr->twcal_timer, j);
goto out;
}
}
j += 1 << INET_TWDR_RECYCLE_TICK;
slot = (slot + 1) & (INET_TWDR_RECYCLE_SLOTS - 1);
}
twdr->twcal_hand = -1;
out:
if ((twdr->tw_count -= killed) == 0)
del_timer(&twdr->tw_timer);
NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITKILLED, killed);
spin_unlock(&twdr->death_lock);
}
EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick);

281
net/ipv4/tcp_minisocks.c
View file

@ -35,12 +35,6 @@
#define SYNC_INIT 1
#endif
/* New-style handling of TIME_WAIT sockets. */
static void inet_twdr_hangman(unsigned long data);
static void inet_twdr_twkill_work(void *data);
static void inet_twdr_twcal_tick(unsigned long data);
int sysctl_tcp_syncookies = SYNC_INIT;
int sysctl_tcp_abort_on_overflow;
@ -63,10 +57,6 @@ struct inet_timewait_death_row tcp_death_row = {
EXPORT_SYMBOL_GPL(tcp_death_row);
static void inet_twsk_schedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr,
const int timeo);
static __inline__ int tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win)
{
if (seq == s_win)
@ -173,9 +163,11 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
if (tw->tw_family == AF_INET &&
tcp_death_row.sysctl_tw_recycle && tcptw->tw_ts_recent_stamp &&
tcp_v4_tw_remember_stamp(tw))
inet_twsk_schedule(tw, &tcp_death_row, tw->tw_timeout);
inet_twsk_schedule(tw, &tcp_death_row, tw->tw_timeout,
TCP_TIMEWAIT_LEN);
else
inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN);
inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN,
TCP_TIMEWAIT_LEN);
return TCP_TW_ACK;
}
@ -213,7 +205,8 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
return TCP_TW_SUCCESS;
}
}
inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN);
inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN,
TCP_TIMEWAIT_LEN);
if (tmp_opt.saw_tstamp) {
tcptw->tw_ts_recent = tmp_opt.rcv_tsval;
@ -263,7 +256,8 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
* Do not reschedule in the last case.
*/
if (paws_reject || th->ack)
inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN);
inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN,
TCP_TIMEWAIT_LEN);
/* Send ACK. Note, we do not put the bucket,
* it will be released by caller.
@ -326,7 +320,8 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
timeo = TCP_TIMEWAIT_LEN;
}
inet_twsk_schedule(tw, &tcp_death_row, timeo);
inet_twsk_schedule(tw, &tcp_death_row, timeo,
TCP_TIMEWAIT_LEN);
inet_twsk_put(tw);
} else {
/* Sorry, if we're out of memory, just CLOSE this
@ -341,261 +336,6 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
tcp_done(sk);
}
/* Returns non-zero if quota exceeded. */
static int inet_twdr_do_twkill_work(struct inet_timewait_death_row *twdr,
const int slot)
{
struct inet_timewait_sock *tw;
struct hlist_node *node;
unsigned int killed;
int ret;
/* NOTE: compare this to previous version where lock
* was released after detaching chain. It was racy,
* because tw buckets are scheduled in not serialized context
* in 2.3 (with netfilter), and with softnet it is common, because
* soft irqs are not sequenced.
*/
killed = 0;
ret = 0;
rescan:
inet_twsk_for_each_inmate(tw, node, &twdr->cells[slot]) {
__inet_twsk_del_dead_node(tw);
spin_unlock(&twdr->death_lock);
__inet_twsk_kill(tw, twdr->hashinfo);
inet_twsk_put(tw);
killed++;
spin_lock(&twdr->death_lock);
if (killed > INET_TWDR_TWKILL_QUOTA) {
ret = 1;
break;
}
/* While we dropped twdr->death_lock, another cpu may have
* killed off the next TW bucket in the list, therefore
* do a fresh re-read of the hlist head node with the
* lock reacquired. We still use the hlist traversal
* macro in order to get the prefetches.
*/
goto rescan;
}
twdr->tw_count -= killed;
NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITED, killed);
return ret;
}
static void inet_twdr_hangman(unsigned long data)
{
struct inet_timewait_death_row *twdr;
int unsigned need_timer;
twdr = (struct inet_timewait_death_row *)data;
spin_lock(&twdr->death_lock);
if (twdr->tw_count == 0)
goto out;
need_timer = 0;
if (inet_twdr_do_twkill_work(twdr, twdr->slot)) {
twdr->thread_slots |= (1 << twdr->slot);
mb();
schedule_work(&twdr->twkill_work);
need_timer = 1;
} else {
/* We purged the entire slot, anything left? */
if (twdr->tw_count)
need_timer = 1;
}
twdr->slot = ((twdr->slot + 1) & (INET_TWDR_TWKILL_SLOTS - 1));
if (need_timer)
mod_timer(&twdr->tw_timer, jiffies + twdr->period);
out:
spin_unlock(&twdr->death_lock);
}
extern void twkill_slots_invalid(void);
static void inet_twdr_twkill_work(void *data)
{
struct inet_timewait_death_row *twdr = data;
int i;
if ((INET_TWDR_TWKILL_SLOTS - 1) > (sizeof(twdr->thread_slots) * 8))
twkill_slots_invalid();
while (twdr->thread_slots) {
spin_lock_bh(&twdr->death_lock);
for (i = 0; i < INET_TWDR_TWKILL_SLOTS; i++) {
if (!(twdr->thread_slots & (1 << i)))
continue;
while (inet_twdr_do_twkill_work(twdr, i) != 0) {
if (need_resched()) {
spin_unlock_bh(&twdr->death_lock);
schedule();
spin_lock_bh(&twdr->death_lock);
}
}
twdr->thread_slots &= ~(1 << i);
}
spin_unlock_bh(&twdr->death_lock);
}
}
/* These are always called from BH context. See callers in
* tcp_input.c to verify this.
*/
/* This is for handling early-kills of TIME_WAIT sockets. */
void inet_twsk_deschedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr)
{
spin_lock(&twdr->death_lock);
if (inet_twsk_del_dead_node(tw)) {
inet_twsk_put(tw);
if (--twdr->tw_count == 0)
del_timer(&twdr->tw_timer);
}
spin_unlock(&twdr->death_lock);
__inet_twsk_kill(tw, twdr->hashinfo);
}
static void inet_twsk_schedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr,
const int timeo)
{
struct hlist_head *list;
int slot;
/* timeout := RTO * 3.5
*
* 3.5 = 1+2+0.5 to wait for two retransmits.
*
* RATIONALE: if FIN arrived and we entered TIME-WAIT state,
* our ACK acking that FIN can be lost. If N subsequent retransmitted
* FINs (or previous seqments) are lost (probability of such event
* is p^(N+1), where p is probability to lose single packet and
* time to detect the loss is about RTO*(2^N - 1) with exponential
* backoff). Normal timewait length is calculated so, that we
* waited at least for one retransmitted FIN (maximal RTO is 120sec).
* [ BTW Linux. following BSD, violates this requirement waiting
* only for 60sec, we should wait at least for 240 secs.
* Well, 240 consumes too much of resources 8)
* ]
* This interval is not reduced to catch old duplicate and
* responces to our wandering segments living for two MSLs.
* However, if we use PAWS to detect
* old duplicates, we can reduce the interval to bounds required
* by RTO, rather than MSL. So, if peer understands PAWS, we
* kill tw bucket after 3.5*RTO (it is important that this number
* is greater than TS tick!) and detect old duplicates with help
* of PAWS.
*/
slot = (timeo + (1 << INET_TWDR_RECYCLE_TICK) - 1) >> INET_TWDR_RECYCLE_TICK;
spin_lock(&twdr->death_lock);
/* Unlink it, if it was scheduled */
if (inet_twsk_del_dead_node(tw))
twdr->tw_count--;
else
atomic_inc(&tw->tw_refcnt);
if (slot >= INET_TWDR_RECYCLE_SLOTS) {
/* Schedule to slow timer */
if (timeo >= TCP_TIMEWAIT_LEN) {
slot = INET_TWDR_TWKILL_SLOTS - 1;
} else {
slot = (timeo + twdr->period - 1) / twdr->period;
if (slot >= INET_TWDR_TWKILL_SLOTS)
slot = INET_TWDR_TWKILL_SLOTS - 1;
}
tw->tw_ttd = jiffies + timeo;
slot = (twdr->slot + slot) & (INET_TWDR_TWKILL_SLOTS - 1);
list = &twdr->cells[slot];
} else {
tw->tw_ttd = jiffies + (slot << INET_TWDR_RECYCLE_TICK);
if (twdr->twcal_hand < 0) {
twdr->twcal_hand = 0;
twdr->twcal_jiffie = jiffies;
twdr->twcal_timer.expires = twdr->twcal_jiffie +
(slot << INET_TWDR_RECYCLE_TICK);
add_timer(&twdr->twcal_timer);
} else {
if (time_after(twdr->twcal_timer.expires,
jiffies + (slot << INET_TWDR_RECYCLE_TICK)))
mod_timer(&twdr->twcal_timer,
jiffies + (slot << INET_TWDR_RECYCLE_TICK));
slot = (twdr->twcal_hand + slot) & (INET_TWDR_RECYCLE_SLOTS - 1);
}
list = &twdr->twcal_row[slot];
}
hlist_add_head(&tw->tw_death_node, list);
if (twdr->tw_count++ == 0)
mod_timer(&twdr->tw_timer, jiffies + twdr->period);
spin_unlock(&twdr->death_lock);
}
void inet_twdr_twcal_tick(unsigned long data)
{
struct inet_timewait_death_row *twdr;
int n, slot;
unsigned long j;
unsigned long now = jiffies;
int killed = 0;
int adv = 0;
twdr = (struct inet_timewait_death_row *)data;
spin_lock(&twdr->death_lock);
if (twdr->twcal_hand < 0)
goto out;
slot = twdr->twcal_hand;
j = twdr->twcal_jiffie;
for (n = 0; n < INET_TWDR_RECYCLE_SLOTS; n++) {
if (time_before_eq(j, now)) {
struct hlist_node *node, *safe;
struct inet_timewait_sock *tw;
inet_twsk_for_each_inmate_safe(tw, node, safe,
&twdr->twcal_row[slot]) {
__inet_twsk_del_dead_node(tw);
__inet_twsk_kill(tw, twdr->hashinfo);
inet_twsk_put(tw);
killed++;
}
} else {
if (!adv) {
adv = 1;
twdr->twcal_jiffie = j;
twdr->twcal_hand = slot;
}
if (!hlist_empty(&twdr->twcal_row[slot])) {
mod_timer(&twdr->twcal_timer, j);
goto out;
}
}
j += 1 << INET_TWDR_RECYCLE_TICK;
slot = (slot + 1) & (INET_TWDR_RECYCLE_SLOTS - 1);
}
twdr->twcal_hand = -1;
out:
if ((twdr->tw_count -= killed) == 0)
del_timer(&twdr->tw_timer);
NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITKILLED, killed);
spin_unlock(&twdr->death_lock);
}
/* This is not only more efficient than what we used to do, it eliminates
* a lot of code duplication between IPv4/IPv6 SYN recv processing. -DaveM
*
@ -933,4 +673,3 @@ EXPORT_SYMBOL(tcp_check_req);
EXPORT_SYMBOL(tcp_child_process);
EXPORT_SYMBOL(tcp_create_openreq_child);
EXPORT_SYMBOL(tcp_timewait_state_process);
EXPORT_SYMBOL(inet_twsk_deschedule);