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-rw-r--r--net/rxrpc/conn_client.c817
1 files changed, 817 insertions, 0 deletions
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
new file mode 100644
index 0000000000..1d95f8bc76
--- /dev/null
+++ b/net/rxrpc/conn_client.c
@@ -0,0 +1,817 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Client connection-specific management code.
+ *
+ * Copyright (C) 2016, 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * Client connections need to be cached for a little while after they've made a
+ * call so as to handle retransmitted DATA packets in case the server didn't
+ * receive the final ACK or terminating ABORT we sent it.
+ *
+ * There are flags of relevance to the cache:
+ *
+ * (2) DONT_REUSE - The connection should be discarded as soon as possible and
+ * should not be reused. This is set when an exclusive connection is used
+ * or a call ID counter overflows.
+ *
+ * The caching state may only be changed if the cache lock is held.
+ *
+ * There are two idle client connection expiry durations. If the total number
+ * of connections is below the reap threshold, we use the normal duration; if
+ * it's above, we use the fast duration.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/timer.h>
+#include <linux/sched/signal.h>
+
+#include "ar-internal.h"
+
+__read_mostly unsigned int rxrpc_reap_client_connections = 900;
+__read_mostly unsigned long rxrpc_conn_idle_client_expiry = 2 * 60 * HZ;
+__read_mostly unsigned long rxrpc_conn_idle_client_fast_expiry = 2 * HZ;
+
+static void rxrpc_activate_bundle(struct rxrpc_bundle *bundle)
+{
+ atomic_inc(&bundle->active);
+}
+
+/*
+ * Release a connection ID for a client connection.
+ */
+static void rxrpc_put_client_connection_id(struct rxrpc_local *local,
+ struct rxrpc_connection *conn)
+{
+ idr_remove(&local->conn_ids, conn->proto.cid >> RXRPC_CIDSHIFT);
+}
+
+/*
+ * Destroy the client connection ID tree.
+ */
+static void rxrpc_destroy_client_conn_ids(struct rxrpc_local *local)
+{
+ struct rxrpc_connection *conn;
+ int id;
+
+ if (!idr_is_empty(&local->conn_ids)) {
+ idr_for_each_entry(&local->conn_ids, conn, id) {
+ pr_err("AF_RXRPC: Leaked client conn %p {%d}\n",
+ conn, refcount_read(&conn->ref));
+ }
+ BUG();
+ }
+
+ idr_destroy(&local->conn_ids);
+}
+
+/*
+ * Allocate a connection bundle.
+ */
+static struct rxrpc_bundle *rxrpc_alloc_bundle(struct rxrpc_call *call,
+ gfp_t gfp)
+{
+ static atomic_t rxrpc_bundle_id;
+ struct rxrpc_bundle *bundle;
+
+ bundle = kzalloc(sizeof(*bundle), gfp);
+ if (bundle) {
+ bundle->local = call->local;
+ bundle->peer = rxrpc_get_peer(call->peer, rxrpc_peer_get_bundle);
+ bundle->key = key_get(call->key);
+ bundle->security = call->security;
+ bundle->exclusive = test_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
+ bundle->upgrade = test_bit(RXRPC_CALL_UPGRADE, &call->flags);
+ bundle->service_id = call->dest_srx.srx_service;
+ bundle->security_level = call->security_level;
+ bundle->debug_id = atomic_inc_return(&rxrpc_bundle_id);
+ refcount_set(&bundle->ref, 1);
+ atomic_set(&bundle->active, 1);
+ INIT_LIST_HEAD(&bundle->waiting_calls);
+ trace_rxrpc_bundle(bundle->debug_id, 1, rxrpc_bundle_new);
+ }
+ return bundle;
+}
+
+struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *bundle,
+ enum rxrpc_bundle_trace why)
+{
+ int r;
+
+ __refcount_inc(&bundle->ref, &r);
+ trace_rxrpc_bundle(bundle->debug_id, r + 1, why);
+ return bundle;
+}
+
+static void rxrpc_free_bundle(struct rxrpc_bundle *bundle)
+{
+ trace_rxrpc_bundle(bundle->debug_id, refcount_read(&bundle->ref),
+ rxrpc_bundle_free);
+ rxrpc_put_peer(bundle->peer, rxrpc_peer_put_bundle);
+ key_put(bundle->key);
+ kfree(bundle);
+}
+
+void rxrpc_put_bundle(struct rxrpc_bundle *bundle, enum rxrpc_bundle_trace why)
+{
+ unsigned int id;
+ bool dead;
+ int r;
+
+ if (bundle) {
+ id = bundle->debug_id;
+ dead = __refcount_dec_and_test(&bundle->ref, &r);
+ trace_rxrpc_bundle(id, r - 1, why);
+ if (dead)
+ rxrpc_free_bundle(bundle);
+ }
+}
+
+/*
+ * Get rid of outstanding client connection preallocations when a local
+ * endpoint is destroyed.
+ */
+void rxrpc_purge_client_connections(struct rxrpc_local *local)
+{
+ rxrpc_destroy_client_conn_ids(local);
+}
+
+/*
+ * Allocate a client connection.
+ */
+static struct rxrpc_connection *
+rxrpc_alloc_client_connection(struct rxrpc_bundle *bundle)
+{
+ struct rxrpc_connection *conn;
+ struct rxrpc_local *local = bundle->local;
+ struct rxrpc_net *rxnet = local->rxnet;
+ int id;
+
+ _enter("");
+
+ conn = rxrpc_alloc_connection(rxnet, GFP_ATOMIC | __GFP_NOWARN);
+ if (!conn)
+ return ERR_PTR(-ENOMEM);
+
+ id = idr_alloc_cyclic(&local->conn_ids, conn, 1, 0x40000000,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (id < 0) {
+ kfree(conn);
+ return ERR_PTR(id);
+ }
+
+ refcount_set(&conn->ref, 1);
+ conn->proto.cid = id << RXRPC_CIDSHIFT;
+ conn->proto.epoch = local->rxnet->epoch;
+ conn->out_clientflag = RXRPC_CLIENT_INITIATED;
+ conn->bundle = rxrpc_get_bundle(bundle, rxrpc_bundle_get_client_conn);
+ conn->local = rxrpc_get_local(bundle->local, rxrpc_local_get_client_conn);
+ conn->peer = rxrpc_get_peer(bundle->peer, rxrpc_peer_get_client_conn);
+ conn->key = key_get(bundle->key);
+ conn->security = bundle->security;
+ conn->exclusive = bundle->exclusive;
+ conn->upgrade = bundle->upgrade;
+ conn->orig_service_id = bundle->service_id;
+ conn->security_level = bundle->security_level;
+ conn->state = RXRPC_CONN_CLIENT_UNSECURED;
+ conn->service_id = conn->orig_service_id;
+
+ if (conn->security == &rxrpc_no_security)
+ conn->state = RXRPC_CONN_CLIENT;
+
+ atomic_inc(&rxnet->nr_conns);
+ write_lock(&rxnet->conn_lock);
+ list_add_tail(&conn->proc_link, &rxnet->conn_proc_list);
+ write_unlock(&rxnet->conn_lock);
+
+ rxrpc_see_connection(conn, rxrpc_conn_new_client);
+
+ atomic_inc(&rxnet->nr_client_conns);
+ trace_rxrpc_client(conn, -1, rxrpc_client_alloc);
+ return conn;
+}
+
+/*
+ * Determine if a connection may be reused.
+ */
+static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn)
+{
+ struct rxrpc_net *rxnet;
+ int id_cursor, id, distance, limit;
+
+ if (!conn)
+ goto dont_reuse;
+
+ rxnet = conn->rxnet;
+ if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags))
+ goto dont_reuse;
+
+ if ((conn->state != RXRPC_CONN_CLIENT_UNSECURED &&
+ conn->state != RXRPC_CONN_CLIENT) ||
+ conn->proto.epoch != rxnet->epoch)
+ goto mark_dont_reuse;
+
+ /* The IDR tree gets very expensive on memory if the connection IDs are
+ * widely scattered throughout the number space, so we shall want to
+ * kill off connections that, say, have an ID more than about four
+ * times the maximum number of client conns away from the current
+ * allocation point to try and keep the IDs concentrated.
+ */
+ id_cursor = idr_get_cursor(&conn->local->conn_ids);
+ id = conn->proto.cid >> RXRPC_CIDSHIFT;
+ distance = id - id_cursor;
+ if (distance < 0)
+ distance = -distance;
+ limit = max_t(unsigned long, atomic_read(&rxnet->nr_conns) * 4, 1024);
+ if (distance > limit)
+ goto mark_dont_reuse;
+
+ return true;
+
+mark_dont_reuse:
+ set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+dont_reuse:
+ return false;
+}
+
+/*
+ * Look up the conn bundle that matches the connection parameters, adding it if
+ * it doesn't yet exist.
+ */
+int rxrpc_look_up_bundle(struct rxrpc_call *call, gfp_t gfp)
+{
+ struct rxrpc_bundle *bundle, *candidate;
+ struct rxrpc_local *local = call->local;
+ struct rb_node *p, **pp, *parent;
+ long diff;
+ bool upgrade = test_bit(RXRPC_CALL_UPGRADE, &call->flags);
+
+ _enter("{%px,%x,%u,%u}",
+ call->peer, key_serial(call->key), call->security_level,
+ upgrade);
+
+ if (test_bit(RXRPC_CALL_EXCLUSIVE, &call->flags)) {
+ call->bundle = rxrpc_alloc_bundle(call, gfp);
+ return call->bundle ? 0 : -ENOMEM;
+ }
+
+ /* First, see if the bundle is already there. */
+ _debug("search 1");
+ spin_lock(&local->client_bundles_lock);
+ p = local->client_bundles.rb_node;
+ while (p) {
+ bundle = rb_entry(p, struct rxrpc_bundle, local_node);
+
+#define cmp(X, Y) ((long)(X) - (long)(Y))
+ diff = (cmp(bundle->peer, call->peer) ?:
+ cmp(bundle->key, call->key) ?:
+ cmp(bundle->security_level, call->security_level) ?:
+ cmp(bundle->upgrade, upgrade));
+#undef cmp
+ if (diff < 0)
+ p = p->rb_left;
+ else if (diff > 0)
+ p = p->rb_right;
+ else
+ goto found_bundle;
+ }
+ spin_unlock(&local->client_bundles_lock);
+ _debug("not found");
+
+ /* It wasn't. We need to add one. */
+ candidate = rxrpc_alloc_bundle(call, gfp);
+ if (!candidate)
+ return -ENOMEM;
+
+ _debug("search 2");
+ spin_lock(&local->client_bundles_lock);
+ pp = &local->client_bundles.rb_node;
+ parent = NULL;
+ while (*pp) {
+ parent = *pp;
+ bundle = rb_entry(parent, struct rxrpc_bundle, local_node);
+
+#define cmp(X, Y) ((long)(X) - (long)(Y))
+ diff = (cmp(bundle->peer, call->peer) ?:
+ cmp(bundle->key, call->key) ?:
+ cmp(bundle->security_level, call->security_level) ?:
+ cmp(bundle->upgrade, upgrade));
+#undef cmp
+ if (diff < 0)
+ pp = &(*pp)->rb_left;
+ else if (diff > 0)
+ pp = &(*pp)->rb_right;
+ else
+ goto found_bundle_free;
+ }
+
+ _debug("new bundle");
+ rb_link_node(&candidate->local_node, parent, pp);
+ rb_insert_color(&candidate->local_node, &local->client_bundles);
+ call->bundle = rxrpc_get_bundle(candidate, rxrpc_bundle_get_client_call);
+ spin_unlock(&local->client_bundles_lock);
+ _leave(" = B=%u [new]", call->bundle->debug_id);
+ return 0;
+
+found_bundle_free:
+ rxrpc_free_bundle(candidate);
+found_bundle:
+ call->bundle = rxrpc_get_bundle(bundle, rxrpc_bundle_get_client_call);
+ rxrpc_activate_bundle(bundle);
+ spin_unlock(&local->client_bundles_lock);
+ _leave(" = B=%u [found]", call->bundle->debug_id);
+ return 0;
+}
+
+/*
+ * Allocate a new connection and add it into a bundle.
+ */
+static bool rxrpc_add_conn_to_bundle(struct rxrpc_bundle *bundle,
+ unsigned int slot)
+{
+ struct rxrpc_connection *conn, *old;
+ unsigned int shift = slot * RXRPC_MAXCALLS;
+ unsigned int i;
+
+ old = bundle->conns[slot];
+ if (old) {
+ bundle->conns[slot] = NULL;
+ trace_rxrpc_client(old, -1, rxrpc_client_replace);
+ rxrpc_put_connection(old, rxrpc_conn_put_noreuse);
+ }
+
+ conn = rxrpc_alloc_client_connection(bundle);
+ if (IS_ERR(conn)) {
+ bundle->alloc_error = PTR_ERR(conn);
+ return false;
+ }
+
+ rxrpc_activate_bundle(bundle);
+ conn->bundle_shift = shift;
+ bundle->conns[slot] = conn;
+ for (i = 0; i < RXRPC_MAXCALLS; i++)
+ set_bit(shift + i, &bundle->avail_chans);
+ return true;
+}
+
+/*
+ * Add a connection to a bundle if there are no usable connections or we have
+ * connections waiting for extra capacity.
+ */
+static bool rxrpc_bundle_has_space(struct rxrpc_bundle *bundle)
+{
+ int slot = -1, i, usable;
+
+ _enter("");
+
+ bundle->alloc_error = 0;
+
+ /* See if there are any usable connections. */
+ usable = 0;
+ for (i = 0; i < ARRAY_SIZE(bundle->conns); i++) {
+ if (rxrpc_may_reuse_conn(bundle->conns[i]))
+ usable++;
+ else if (slot == -1)
+ slot = i;
+ }
+
+ if (!usable && bundle->upgrade)
+ bundle->try_upgrade = true;
+
+ if (!usable)
+ goto alloc_conn;
+
+ if (!bundle->avail_chans &&
+ !bundle->try_upgrade &&
+ usable < ARRAY_SIZE(bundle->conns))
+ goto alloc_conn;
+
+ _leave("");
+ return usable;
+
+alloc_conn:
+ return slot >= 0 ? rxrpc_add_conn_to_bundle(bundle, slot) : false;
+}
+
+/*
+ * Assign a channel to the call at the front of the queue and wake the call up.
+ * We don't increment the callNumber counter until this number has been exposed
+ * to the world.
+ */
+static void rxrpc_activate_one_channel(struct rxrpc_connection *conn,
+ unsigned int channel)
+{
+ struct rxrpc_channel *chan = &conn->channels[channel];
+ struct rxrpc_bundle *bundle = conn->bundle;
+ struct rxrpc_call *call = list_entry(bundle->waiting_calls.next,
+ struct rxrpc_call, wait_link);
+ u32 call_id = chan->call_counter + 1;
+
+ _enter("C=%x,%u", conn->debug_id, channel);
+
+ list_del_init(&call->wait_link);
+
+ trace_rxrpc_client(conn, channel, rxrpc_client_chan_activate);
+
+ /* Cancel the final ACK on the previous call if it hasn't been sent yet
+ * as the DATA packet will implicitly ACK it.
+ */
+ clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags);
+ clear_bit(conn->bundle_shift + channel, &bundle->avail_chans);
+
+ rxrpc_see_call(call, rxrpc_call_see_activate_client);
+ call->conn = rxrpc_get_connection(conn, rxrpc_conn_get_activate_call);
+ call->cid = conn->proto.cid | channel;
+ call->call_id = call_id;
+ call->dest_srx.srx_service = conn->service_id;
+ call->cong_ssthresh = call->peer->cong_ssthresh;
+ if (call->cong_cwnd >= call->cong_ssthresh)
+ call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+ else
+ call->cong_mode = RXRPC_CALL_SLOW_START;
+
+ chan->call_id = call_id;
+ chan->call_debug_id = call->debug_id;
+ chan->call = call;
+
+ rxrpc_see_call(call, rxrpc_call_see_connected);
+ trace_rxrpc_connect_call(call);
+ call->tx_last_sent = ktime_get_real();
+ rxrpc_start_call_timer(call);
+ rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_SEND_REQUEST);
+ wake_up(&call->waitq);
+}
+
+/*
+ * Remove a connection from the idle list if it's on it.
+ */
+static void rxrpc_unidle_conn(struct rxrpc_connection *conn)
+{
+ if (!list_empty(&conn->cache_link)) {
+ list_del_init(&conn->cache_link);
+ rxrpc_put_connection(conn, rxrpc_conn_put_unidle);
+ }
+}
+
+/*
+ * Assign channels and callNumbers to waiting calls.
+ */
+static void rxrpc_activate_channels(struct rxrpc_bundle *bundle)
+{
+ struct rxrpc_connection *conn;
+ unsigned long avail, mask;
+ unsigned int channel, slot;
+
+ trace_rxrpc_client(NULL, -1, rxrpc_client_activate_chans);
+
+ if (bundle->try_upgrade)
+ mask = 1;
+ else
+ mask = ULONG_MAX;
+
+ while (!list_empty(&bundle->waiting_calls)) {
+ avail = bundle->avail_chans & mask;
+ if (!avail)
+ break;
+ channel = __ffs(avail);
+ clear_bit(channel, &bundle->avail_chans);
+
+ slot = channel / RXRPC_MAXCALLS;
+ conn = bundle->conns[slot];
+ if (!conn)
+ break;
+
+ if (bundle->try_upgrade)
+ set_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags);
+ rxrpc_unidle_conn(conn);
+
+ channel &= (RXRPC_MAXCALLS - 1);
+ conn->act_chans |= 1 << channel;
+ rxrpc_activate_one_channel(conn, channel);
+ }
+}
+
+/*
+ * Connect waiting channels (called from the I/O thread).
+ */
+void rxrpc_connect_client_calls(struct rxrpc_local *local)
+{
+ struct rxrpc_call *call;
+
+ while ((call = list_first_entry_or_null(&local->new_client_calls,
+ struct rxrpc_call, wait_link))
+ ) {
+ struct rxrpc_bundle *bundle = call->bundle;
+
+ spin_lock(&local->client_call_lock);
+ list_move_tail(&call->wait_link, &bundle->waiting_calls);
+ spin_unlock(&local->client_call_lock);
+
+ if (rxrpc_bundle_has_space(bundle))
+ rxrpc_activate_channels(bundle);
+ }
+}
+
+/*
+ * Note that a call, and thus a connection, is about to be exposed to the
+ * world.
+ */
+void rxrpc_expose_client_call(struct rxrpc_call *call)
+{
+ unsigned int channel = call->cid & RXRPC_CHANNELMASK;
+ struct rxrpc_connection *conn = call->conn;
+ struct rxrpc_channel *chan = &conn->channels[channel];
+
+ if (!test_and_set_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+ /* Mark the call ID as being used. If the callNumber counter
+ * exceeds ~2 billion, we kill the connection after its
+ * outstanding calls have finished so that the counter doesn't
+ * wrap.
+ */
+ chan->call_counter++;
+ if (chan->call_counter >= INT_MAX)
+ set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+ trace_rxrpc_client(conn, channel, rxrpc_client_exposed);
+
+ spin_lock(&call->peer->lock);
+ hlist_add_head(&call->error_link, &call->peer->error_targets);
+ spin_unlock(&call->peer->lock);
+ }
+}
+
+/*
+ * Set the reap timer.
+ */
+static void rxrpc_set_client_reap_timer(struct rxrpc_local *local)
+{
+ if (!local->kill_all_client_conns) {
+ unsigned long now = jiffies;
+ unsigned long reap_at = now + rxrpc_conn_idle_client_expiry;
+
+ if (local->rxnet->live)
+ timer_reduce(&local->client_conn_reap_timer, reap_at);
+ }
+}
+
+/*
+ * Disconnect a client call.
+ */
+void rxrpc_disconnect_client_call(struct rxrpc_bundle *bundle, struct rxrpc_call *call)
+{
+ struct rxrpc_connection *conn;
+ struct rxrpc_channel *chan = NULL;
+ struct rxrpc_local *local = bundle->local;
+ unsigned int channel;
+ bool may_reuse;
+ u32 cid;
+
+ _enter("c=%x", call->debug_id);
+
+ /* Calls that have never actually been assigned a channel can simply be
+ * discarded.
+ */
+ conn = call->conn;
+ if (!conn) {
+ _debug("call is waiting");
+ ASSERTCMP(call->call_id, ==, 0);
+ ASSERT(!test_bit(RXRPC_CALL_EXPOSED, &call->flags));
+ list_del_init(&call->wait_link);
+ return;
+ }
+
+ cid = call->cid;
+ channel = cid & RXRPC_CHANNELMASK;
+ chan = &conn->channels[channel];
+ trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect);
+
+ if (WARN_ON(chan->call != call))
+ return;
+
+ may_reuse = rxrpc_may_reuse_conn(conn);
+
+ /* If a client call was exposed to the world, we save the result for
+ * retransmission.
+ *
+ * We use a barrier here so that the call number and abort code can be
+ * read without needing to take a lock.
+ *
+ * TODO: Make the incoming packet handler check this and handle
+ * terminal retransmission without requiring access to the call.
+ */
+ if (test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+ _debug("exposed %u,%u", call->call_id, call->abort_code);
+ __rxrpc_disconnect_call(conn, call);
+
+ if (test_and_clear_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) {
+ trace_rxrpc_client(conn, channel, rxrpc_client_to_active);
+ bundle->try_upgrade = false;
+ if (may_reuse)
+ rxrpc_activate_channels(bundle);
+ }
+ }
+
+ /* See if we can pass the channel directly to another call. */
+ if (may_reuse && !list_empty(&bundle->waiting_calls)) {
+ trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass);
+ rxrpc_activate_one_channel(conn, channel);
+ return;
+ }
+
+ /* Schedule the final ACK to be transmitted in a short while so that it
+ * can be skipped if we find a follow-on call. The first DATA packet
+ * of the follow on call will implicitly ACK this call.
+ */
+ if (call->completion == RXRPC_CALL_SUCCEEDED &&
+ test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+ unsigned long final_ack_at = jiffies + 2;
+
+ WRITE_ONCE(chan->final_ack_at, final_ack_at);
+ smp_wmb(); /* vs rxrpc_process_delayed_final_acks() */
+ set_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags);
+ rxrpc_reduce_conn_timer(conn, final_ack_at);
+ }
+
+ /* Deactivate the channel. */
+ chan->call = NULL;
+ set_bit(conn->bundle_shift + channel, &conn->bundle->avail_chans);
+ conn->act_chans &= ~(1 << channel);
+
+ /* If no channels remain active, then put the connection on the idle
+ * list for a short while. Give it a ref to stop it going away if it
+ * becomes unbundled.
+ */
+ if (!conn->act_chans) {
+ trace_rxrpc_client(conn, channel, rxrpc_client_to_idle);
+ conn->idle_timestamp = jiffies;
+
+ rxrpc_get_connection(conn, rxrpc_conn_get_idle);
+ list_move_tail(&conn->cache_link, &local->idle_client_conns);
+
+ rxrpc_set_client_reap_timer(local);
+ }
+}
+
+/*
+ * Remove a connection from a bundle.
+ */
+static void rxrpc_unbundle_conn(struct rxrpc_connection *conn)
+{
+ struct rxrpc_bundle *bundle = conn->bundle;
+ unsigned int bindex;
+ int i;
+
+ _enter("C=%x", conn->debug_id);
+
+ if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
+ rxrpc_process_delayed_final_acks(conn, true);
+
+ bindex = conn->bundle_shift / RXRPC_MAXCALLS;
+ if (bundle->conns[bindex] == conn) {
+ _debug("clear slot %u", bindex);
+ bundle->conns[bindex] = NULL;
+ for (i = 0; i < RXRPC_MAXCALLS; i++)
+ clear_bit(conn->bundle_shift + i, &bundle->avail_chans);
+ rxrpc_put_client_connection_id(bundle->local, conn);
+ rxrpc_deactivate_bundle(bundle);
+ rxrpc_put_connection(conn, rxrpc_conn_put_unbundle);
+ }
+}
+
+/*
+ * Drop the active count on a bundle.
+ */
+void rxrpc_deactivate_bundle(struct rxrpc_bundle *bundle)
+{
+ struct rxrpc_local *local;
+ bool need_put = false;
+
+ if (!bundle)
+ return;
+
+ local = bundle->local;
+ if (atomic_dec_and_lock(&bundle->active, &local->client_bundles_lock)) {
+ if (!bundle->exclusive) {
+ _debug("erase bundle");
+ rb_erase(&bundle->local_node, &local->client_bundles);
+ need_put = true;
+ }
+
+ spin_unlock(&local->client_bundles_lock);
+ if (need_put)
+ rxrpc_put_bundle(bundle, rxrpc_bundle_put_discard);
+ }
+}
+
+/*
+ * Clean up a dead client connection.
+ */
+void rxrpc_kill_client_conn(struct rxrpc_connection *conn)
+{
+ struct rxrpc_local *local = conn->local;
+ struct rxrpc_net *rxnet = local->rxnet;
+
+ _enter("C=%x", conn->debug_id);
+
+ trace_rxrpc_client(conn, -1, rxrpc_client_cleanup);
+ atomic_dec(&rxnet->nr_client_conns);
+
+ rxrpc_put_client_connection_id(local, conn);
+}
+
+/*
+ * Discard expired client connections from the idle list. Each conn in the
+ * idle list has been exposed and holds an extra ref because of that.
+ *
+ * This may be called from conn setup or from a work item so cannot be
+ * considered non-reentrant.
+ */
+void rxrpc_discard_expired_client_conns(struct rxrpc_local *local)
+{
+ struct rxrpc_connection *conn;
+ unsigned long expiry, conn_expires_at, now;
+ unsigned int nr_conns;
+
+ _enter("");
+
+ /* We keep an estimate of what the number of conns ought to be after
+ * we've discarded some so that we don't overdo the discarding.
+ */
+ nr_conns = atomic_read(&local->rxnet->nr_client_conns);
+
+next:
+ conn = list_first_entry_or_null(&local->idle_client_conns,
+ struct rxrpc_connection, cache_link);
+ if (!conn)
+ return;
+
+ if (!local->kill_all_client_conns) {
+ /* If the number of connections is over the reap limit, we
+ * expedite discard by reducing the expiry timeout. We must,
+ * however, have at least a short grace period to be able to do
+ * final-ACK or ABORT retransmission.
+ */
+ expiry = rxrpc_conn_idle_client_expiry;
+ if (nr_conns > rxrpc_reap_client_connections)
+ expiry = rxrpc_conn_idle_client_fast_expiry;
+ if (conn->local->service_closed)
+ expiry = rxrpc_closed_conn_expiry * HZ;
+
+ conn_expires_at = conn->idle_timestamp + expiry;
+
+ now = READ_ONCE(jiffies);
+ if (time_after(conn_expires_at, now))
+ goto not_yet_expired;
+ }
+
+ atomic_dec(&conn->active);
+ trace_rxrpc_client(conn, -1, rxrpc_client_discard);
+ list_del_init(&conn->cache_link);
+
+ rxrpc_unbundle_conn(conn);
+ /* Drop the ->cache_link ref */
+ rxrpc_put_connection(conn, rxrpc_conn_put_discard_idle);
+
+ nr_conns--;
+ goto next;
+
+not_yet_expired:
+ /* The connection at the front of the queue hasn't yet expired, so
+ * schedule the work item for that point if we discarded something.
+ *
+ * We don't worry if the work item is already scheduled - it can look
+ * after rescheduling itself at a later time. We could cancel it, but
+ * then things get messier.
+ */
+ _debug("not yet");
+ if (!local->kill_all_client_conns)
+ timer_reduce(&local->client_conn_reap_timer, conn_expires_at);
+
+ _leave("");
+}
+
+/*
+ * Clean up the client connections on a local endpoint.
+ */
+void rxrpc_clean_up_local_conns(struct rxrpc_local *local)
+{
+ struct rxrpc_connection *conn;
+
+ _enter("");
+
+ local->kill_all_client_conns = true;
+
+ del_timer_sync(&local->client_conn_reap_timer);
+
+ while ((conn = list_first_entry_or_null(&local->idle_client_conns,
+ struct rxrpc_connection, cache_link))) {
+ list_del_init(&conn->cache_link);
+ atomic_dec(&conn->active);
+ trace_rxrpc_client(conn, -1, rxrpc_client_discard);
+ rxrpc_unbundle_conn(conn);
+ rxrpc_put_connection(conn, rxrpc_conn_put_local_dead);
+ }
+
+ _leave(" [culled]");
+}