[TIMEWAIT]: Introduce inet_timewait_death_row
That groups all of the tables and variables associated to the TCP timewait
schedulling/recycling/killing code, that now can be isolated from the TCP
specific code and used by other transport protocols, such as DCCP.
Next changeset will move this code to net/ipv4/inet_timewait_sock.c
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 2d95afe..81b9a52 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -35,13 +35,37 @@
#define SYNC_INIT 1
#endif
-int sysctl_tcp_tw_recycle;
-int sysctl_tcp_max_tw_buckets = NR_FILE*2;
+/* 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;
-static void tcp_tw_schedule(struct inet_timewait_sock *tw, int timeo);
+struct inet_timewait_death_row tcp_death_row = {
+ .sysctl_max_tw_buckets = NR_FILE * 2,
+ .period = TCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
+ .death_lock = SPIN_LOCK_UNLOCKED,
+ .hashinfo = &tcp_hashinfo,
+ .tw_timer = TIMER_INITIALIZER(inet_twdr_hangman, 0,
+ (unsigned long)&tcp_death_row),
+ .twkill_work = __WORK_INITIALIZER(tcp_death_row.twkill_work,
+ inet_twdr_twkill_work,
+ &tcp_death_row),
+/* Short-time timewait calendar */
+
+ .twcal_hand = -1,
+ .twcal_timer = TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
+ (unsigned long)&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)
{
@@ -52,10 +76,6 @@
return (seq == e_win && seq == end_seq);
}
-/* New-style handling of TIME_WAIT sockets. */
-
-int tcp_tw_count;
-
/*
* * Main purpose of TIME-WAIT state is to close connection gracefully,
* when one of ends sits in LAST-ACK or CLOSING retransmitting FIN
@@ -132,7 +152,7 @@
if (!th->fin ||
TCP_SKB_CB(skb)->end_seq != tcptw->tw_rcv_nxt + 1) {
kill_with_rst:
- tcp_tw_deschedule(tw);
+ inet_twsk_deschedule(tw, &tcp_death_row);
inet_twsk_put(tw);
return TCP_TW_RST;
}
@@ -151,11 +171,11 @@
* do not undertsnad recycling in any case, it not
* a big problem in practice. --ANK */
if (tw->tw_family == AF_INET &&
- sysctl_tcp_tw_recycle && tcptw->tw_ts_recent_stamp &&
+ tcp_death_row.sysctl_tw_recycle && tcptw->tw_ts_recent_stamp &&
tcp_v4_tw_remember_stamp(tw))
- tcp_tw_schedule(tw, tw->tw_timeout);
+ inet_twsk_schedule(tw, &tcp_death_row, tw->tw_timeout);
else
- tcp_tw_schedule(tw, TCP_TIMEWAIT_LEN);
+ inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN);
return TCP_TW_ACK;
}
@@ -188,12 +208,12 @@
*/
if (sysctl_tcp_rfc1337 == 0) {
kill:
- tcp_tw_deschedule(tw);
+ inet_twsk_deschedule(tw, &tcp_death_row);
inet_twsk_put(tw);
return TCP_TW_SUCCESS;
}
}
- tcp_tw_schedule(tw, TCP_TIMEWAIT_LEN);
+ inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN);
if (tmp_opt.saw_tstamp) {
tcptw->tw_ts_recent = tmp_opt.rcv_tsval;
@@ -243,7 +263,7 @@
* Do not reschedule in the last case.
*/
if (paws_reject || th->ack)
- tcp_tw_schedule(tw, TCP_TIMEWAIT_LEN);
+ inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN);
/* Send ACK. Note, we do not put the bucket,
* it will be released by caller.
@@ -263,10 +283,10 @@
const struct tcp_sock *tp = tcp_sk(sk);
int recycle_ok = 0;
- if (sysctl_tcp_tw_recycle && tp->rx_opt.ts_recent_stamp)
+ if (tcp_death_row.sysctl_tw_recycle && tp->rx_opt.ts_recent_stamp)
recycle_ok = tp->af_specific->remember_stamp(sk);
- if (tcp_tw_count < sysctl_tcp_max_tw_buckets)
+ if (tcp_death_row.tw_count < tcp_death_row.sysctl_max_tw_buckets)
tw = inet_twsk_alloc(sk, state);
if (tw != NULL) {
@@ -306,7 +326,7 @@
timeo = TCP_TIMEWAIT_LEN;
}
- tcp_tw_schedule(tw, timeo);
+ inet_twsk_schedule(tw, &tcp_death_row, timeo);
inet_twsk_put(tw);
} else {
/* Sorry, if we're out of memory, just CLOSE this
@@ -321,26 +341,9 @@
tcp_done(sk);
}
-/* Kill off TIME_WAIT sockets once their lifetime has expired. */
-static int tcp_tw_death_row_slot;
-
-static void tcp_twkill(unsigned long);
-
-/* TIME_WAIT reaping mechanism. */
-#define TCP_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
-#define TCP_TWKILL_PERIOD (TCP_TIMEWAIT_LEN/TCP_TWKILL_SLOTS)
-
-#define TCP_TWKILL_QUOTA 100
-
-static struct hlist_head tcp_tw_death_row[TCP_TWKILL_SLOTS];
-static DEFINE_SPINLOCK(tw_death_lock);
-static struct timer_list tcp_tw_timer = TIMER_INITIALIZER(tcp_twkill, 0, 0);
-static void twkill_work(void *);
-static DECLARE_WORK(tcp_twkill_work, twkill_work, NULL);
-static u32 twkill_thread_slots;
-
/* Returns non-zero if quota exceeded. */
-static int tcp_do_twkill_work(int slot, unsigned int quota)
+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;
@@ -356,19 +359,19 @@
killed = 0;
ret = 0;
rescan:
- inet_twsk_for_each_inmate(tw, node, &tcp_tw_death_row[slot]) {
+ inet_twsk_for_each_inmate(tw, node, &twdr->cells[slot]) {
__inet_twsk_del_dead_node(tw);
- spin_unlock(&tw_death_lock);
- __inet_twsk_kill(tw, &tcp_hashinfo);
+ spin_unlock(&twdr->death_lock);
+ __inet_twsk_kill(tw, twdr->hashinfo);
inet_twsk_put(tw);
killed++;
- spin_lock(&tw_death_lock);
- if (killed > quota) {
+ spin_lock(&twdr->death_lock);
+ if (killed > INET_TWDR_TWKILL_QUOTA) {
ret = 1;
break;
}
- /* While we dropped tw_death_lock, another cpu may have
+ /* 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
@@ -377,67 +380,68 @@
goto rescan;
}
- tcp_tw_count -= killed;
+ twdr->tw_count -= killed;
NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITED, killed);
return ret;
}
-static void tcp_twkill(unsigned long dummy)
+static void inet_twdr_hangman(unsigned long data)
{
- int need_timer, ret;
+ struct inet_timewait_death_row *twdr;
+ int unsigned need_timer;
- spin_lock(&tw_death_lock);
+ twdr = (struct inet_timewait_death_row *)data;
+ spin_lock(&twdr->death_lock);
- if (tcp_tw_count == 0)
+ if (twdr->tw_count == 0)
goto out;
need_timer = 0;
- ret = tcp_do_twkill_work(tcp_tw_death_row_slot, TCP_TWKILL_QUOTA);
- if (ret) {
- twkill_thread_slots |= (1 << tcp_tw_death_row_slot);
+ if (inet_twdr_do_twkill_work(twdr, twdr->slot)) {
+ twdr->thread_slots |= (1 << twdr->slot);
mb();
- schedule_work(&tcp_twkill_work);
+ schedule_work(&twdr->twkill_work);
need_timer = 1;
} else {
/* We purged the entire slot, anything left? */
- if (tcp_tw_count)
+ if (twdr->tw_count)
need_timer = 1;
}
- tcp_tw_death_row_slot =
- ((tcp_tw_death_row_slot + 1) & (TCP_TWKILL_SLOTS - 1));
+ twdr->slot = ((twdr->slot + 1) & (INET_TWDR_TWKILL_SLOTS - 1));
if (need_timer)
- mod_timer(&tcp_tw_timer, jiffies + TCP_TWKILL_PERIOD);
+ mod_timer(&twdr->tw_timer, jiffies + twdr->period);
out:
- spin_unlock(&tw_death_lock);
+ spin_unlock(&twdr->death_lock);
}
extern void twkill_slots_invalid(void);
-static void twkill_work(void *dummy)
+static void inet_twdr_twkill_work(void *data)
{
+ struct inet_timewait_death_row *twdr = data;
int i;
- if ((TCP_TWKILL_SLOTS - 1) > (sizeof(twkill_thread_slots) * 8))
+ if ((INET_TWDR_TWKILL_SLOTS - 1) > (sizeof(twdr->thread_slots) * 8))
twkill_slots_invalid();
- while (twkill_thread_slots) {
- spin_lock_bh(&tw_death_lock);
- for (i = 0; i < TCP_TWKILL_SLOTS; i++) {
- if (!(twkill_thread_slots & (1 << i)))
+ 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 (tcp_do_twkill_work(i, TCP_TWKILL_QUOTA) != 0) {
+ while (inet_twdr_do_twkill_work(twdr, i) != 0) {
if (need_resched()) {
- spin_unlock_bh(&tw_death_lock);
+ spin_unlock_bh(&twdr->death_lock);
schedule();
- spin_lock_bh(&tw_death_lock);
+ spin_lock_bh(&twdr->death_lock);
}
}
- twkill_thread_slots &= ~(1 << i);
+ twdr->thread_slots &= ~(1 << i);
}
- spin_unlock_bh(&tw_death_lock);
+ spin_unlock_bh(&twdr->death_lock);
}
}
@@ -446,28 +450,22 @@
*/
/* This is for handling early-kills of TIME_WAIT sockets. */
-void tcp_tw_deschedule(struct inet_timewait_sock *tw)
+void inet_twsk_deschedule(struct inet_timewait_sock *tw,
+ struct inet_timewait_death_row *twdr)
{
- spin_lock(&tw_death_lock);
+ spin_lock(&twdr->death_lock);
if (inet_twsk_del_dead_node(tw)) {
inet_twsk_put(tw);
- if (--tcp_tw_count == 0)
- del_timer(&tcp_tw_timer);
+ if (--twdr->tw_count == 0)
+ del_timer(&twdr->tw_timer);
}
- spin_unlock(&tw_death_lock);
- __inet_twsk_kill(tw, &tcp_hashinfo);
+ spin_unlock(&twdr->death_lock);
+ __inet_twsk_kill(tw, twdr->hashinfo);
}
-/* Short-time timewait calendar */
-
-static int tcp_twcal_hand = -1;
-static int tcp_twcal_jiffie;
-static void tcp_twcal_tick(unsigned long);
-static struct timer_list tcp_twcal_timer =
- TIMER_INITIALIZER(tcp_twcal_tick, 0, 0);
-static struct hlist_head tcp_twcal_row[TCP_TW_RECYCLE_SLOTS];
-
-static void tcp_tw_schedule(struct inet_timewait_sock *tw, const int timeo)
+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;
@@ -496,100 +494,106 @@
* is greater than TS tick!) and detect old duplicates with help
* of PAWS.
*/
- slot = (timeo + (1<<TCP_TW_RECYCLE_TICK) - 1) >> TCP_TW_RECYCLE_TICK;
+ slot = (timeo + (1 << INET_TWDR_RECYCLE_TICK) - 1) >> INET_TWDR_RECYCLE_TICK;
- spin_lock(&tw_death_lock);
+ spin_lock(&twdr->death_lock);
/* Unlink it, if it was scheduled */
if (inet_twsk_del_dead_node(tw))
- tcp_tw_count--;
+ twdr->tw_count--;
else
atomic_inc(&tw->tw_refcnt);
- if (slot >= TCP_TW_RECYCLE_SLOTS) {
+ if (slot >= INET_TWDR_RECYCLE_SLOTS) {
/* Schedule to slow timer */
if (timeo >= TCP_TIMEWAIT_LEN) {
- slot = TCP_TWKILL_SLOTS-1;
+ slot = INET_TWDR_TWKILL_SLOTS - 1;
} else {
- slot = (timeo + TCP_TWKILL_PERIOD-1) / TCP_TWKILL_PERIOD;
- if (slot >= TCP_TWKILL_SLOTS)
- slot = TCP_TWKILL_SLOTS-1;
+ 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 = (tcp_tw_death_row_slot + slot) & (TCP_TWKILL_SLOTS - 1);
- list = &tcp_tw_death_row[slot];
+ slot = (twdr->slot + slot) & (INET_TWDR_TWKILL_SLOTS - 1);
+ list = &twdr->cells[slot];
} else {
- tw->tw_ttd = jiffies + (slot << TCP_TW_RECYCLE_TICK);
+ tw->tw_ttd = jiffies + (slot << INET_TWDR_RECYCLE_TICK);
- if (tcp_twcal_hand < 0) {
- tcp_twcal_hand = 0;
- tcp_twcal_jiffie = jiffies;
- tcp_twcal_timer.expires = tcp_twcal_jiffie + (slot<<TCP_TW_RECYCLE_TICK);
- add_timer(&tcp_twcal_timer);
+ 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(tcp_twcal_timer.expires, jiffies + (slot<<TCP_TW_RECYCLE_TICK)))
- mod_timer(&tcp_twcal_timer, jiffies + (slot<<TCP_TW_RECYCLE_TICK));
- slot = (tcp_twcal_hand + slot)&(TCP_TW_RECYCLE_SLOTS-1);
+ 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 = &tcp_twcal_row[slot];
+ list = &twdr->twcal_row[slot];
}
hlist_add_head(&tw->tw_death_node, list);
- if (tcp_tw_count++ == 0)
- mod_timer(&tcp_tw_timer, jiffies+TCP_TWKILL_PERIOD);
- spin_unlock(&tw_death_lock);
+ if (twdr->tw_count++ == 0)
+ mod_timer(&twdr->tw_timer, jiffies + twdr->period);
+ spin_unlock(&twdr->death_lock);
}
-void tcp_twcal_tick(unsigned long dummy)
+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;
- spin_lock(&tw_death_lock);
- if (tcp_twcal_hand < 0)
+ twdr = (struct inet_timewait_death_row *)data;
+
+ spin_lock(&twdr->death_lock);
+ if (twdr->twcal_hand < 0)
goto out;
- slot = tcp_twcal_hand;
- j = tcp_twcal_jiffie;
+ slot = twdr->twcal_hand;
+ j = twdr->twcal_jiffie;
- for (n=0; n<TCP_TW_RECYCLE_SLOTS; n++) {
+ 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,
- &tcp_twcal_row[slot]) {
+ &twdr->twcal_row[slot]) {
__inet_twsk_del_dead_node(tw);
- __inet_twsk_kill(tw, &tcp_hashinfo);
+ __inet_twsk_kill(tw, twdr->hashinfo);
inet_twsk_put(tw);
killed++;
}
} else {
if (!adv) {
adv = 1;
- tcp_twcal_jiffie = j;
- tcp_twcal_hand = slot;
+ twdr->twcal_jiffie = j;
+ twdr->twcal_hand = slot;
}
- if (!hlist_empty(&tcp_twcal_row[slot])) {
- mod_timer(&tcp_twcal_timer, j);
+ if (!hlist_empty(&twdr->twcal_row[slot])) {
+ mod_timer(&twdr->twcal_timer, j);
goto out;
}
}
- j += (1<<TCP_TW_RECYCLE_TICK);
- slot = (slot+1)&(TCP_TW_RECYCLE_SLOTS-1);
+ j += 1 << INET_TWDR_RECYCLE_TICK;
+ slot = (slot + 1) & (INET_TWDR_RECYCLE_SLOTS - 1);
}
- tcp_twcal_hand = -1;
+ twdr->twcal_hand = -1;
out:
- if ((tcp_tw_count -= killed) == 0)
- del_timer(&tcp_tw_timer);
+ if ((twdr->tw_count -= killed) == 0)
+ del_timer(&twdr->tw_timer);
NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITKILLED, killed);
- spin_unlock(&tw_death_lock);
+ spin_unlock(&twdr->death_lock);
}
/* This is not only more efficient than what we used to do, it eliminates
@@ -929,4 +933,4 @@
EXPORT_SYMBOL(tcp_child_process);
EXPORT_SYMBOL(tcp_create_openreq_child);
EXPORT_SYMBOL(tcp_timewait_state_process);
-EXPORT_SYMBOL(tcp_tw_deschedule);
+EXPORT_SYMBOL(inet_twsk_deschedule);