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

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>

1 files changed, 10 insertions, 271 deletions

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 81b9a52c50c6..dc085233d512 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -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 @@ kill_with_rst:
                 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 @@ kill:
                                 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 @@ kill:
                  * 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);