summaryrefslogtreecommitdiffstats
path: root/net/rxrpc/conn_client.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /net/rxrpc/conn_client.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/rxrpc/conn_client.c')
-rw-r--r--net/rxrpc/conn_client.c1131
1 files changed, 1131 insertions, 0 deletions
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
new file mode 100644
index 000000000..bdb335cb2
--- /dev/null
+++ b/net/rxrpc/conn_client.c
@@ -0,0 +1,1131 @@
+// 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;
+
+/*
+ * We use machine-unique IDs for our client connections.
+ */
+DEFINE_IDR(rxrpc_client_conn_ids);
+static DEFINE_SPINLOCK(rxrpc_conn_id_lock);
+
+static void rxrpc_deactivate_bundle(struct rxrpc_bundle *bundle);
+
+/*
+ * Get a connection ID and epoch for a client connection from the global pool.
+ * The connection struct pointer is then recorded in the idr radix tree. The
+ * epoch doesn't change until the client is rebooted (or, at least, unless the
+ * module is unloaded).
+ */
+static int rxrpc_get_client_connection_id(struct rxrpc_connection *conn,
+ gfp_t gfp)
+{
+ struct rxrpc_net *rxnet = conn->params.local->rxnet;
+ int id;
+
+ _enter("");
+
+ idr_preload(gfp);
+ spin_lock(&rxrpc_conn_id_lock);
+
+ id = idr_alloc_cyclic(&rxrpc_client_conn_ids, conn,
+ 1, 0x40000000, GFP_NOWAIT);
+ if (id < 0)
+ goto error;
+
+ spin_unlock(&rxrpc_conn_id_lock);
+ idr_preload_end();
+
+ conn->proto.epoch = rxnet->epoch;
+ conn->proto.cid = id << RXRPC_CIDSHIFT;
+ set_bit(RXRPC_CONN_HAS_IDR, &conn->flags);
+ _leave(" [CID %x]", conn->proto.cid);
+ return 0;
+
+error:
+ spin_unlock(&rxrpc_conn_id_lock);
+ idr_preload_end();
+ _leave(" = %d", id);
+ return id;
+}
+
+/*
+ * Release a connection ID for a client connection from the global pool.
+ */
+static void rxrpc_put_client_connection_id(struct rxrpc_connection *conn)
+{
+ if (test_bit(RXRPC_CONN_HAS_IDR, &conn->flags)) {
+ spin_lock(&rxrpc_conn_id_lock);
+ idr_remove(&rxrpc_client_conn_ids,
+ conn->proto.cid >> RXRPC_CIDSHIFT);
+ spin_unlock(&rxrpc_conn_id_lock);
+ }
+}
+
+/*
+ * Destroy the client connection ID tree.
+ */
+void rxrpc_destroy_client_conn_ids(void)
+{
+ struct rxrpc_connection *conn;
+ int id;
+
+ if (!idr_is_empty(&rxrpc_client_conn_ids)) {
+ idr_for_each_entry(&rxrpc_client_conn_ids, conn, id) {
+ pr_err("AF_RXRPC: Leaked client conn %p {%d}\n",
+ conn, refcount_read(&conn->ref));
+ }
+ BUG();
+ }
+
+ idr_destroy(&rxrpc_client_conn_ids);
+}
+
+/*
+ * Allocate a connection bundle.
+ */
+static struct rxrpc_bundle *rxrpc_alloc_bundle(struct rxrpc_conn_parameters *cp,
+ gfp_t gfp)
+{
+ struct rxrpc_bundle *bundle;
+
+ bundle = kzalloc(sizeof(*bundle), gfp);
+ if (bundle) {
+ bundle->params = *cp;
+ rxrpc_get_peer(bundle->params.peer);
+ refcount_set(&bundle->ref, 1);
+ atomic_set(&bundle->active, 1);
+ spin_lock_init(&bundle->channel_lock);
+ INIT_LIST_HEAD(&bundle->waiting_calls);
+ }
+ return bundle;
+}
+
+struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *bundle)
+{
+ refcount_inc(&bundle->ref);
+ return bundle;
+}
+
+static void rxrpc_free_bundle(struct rxrpc_bundle *bundle)
+{
+ rxrpc_put_peer(bundle->params.peer);
+ kfree(bundle);
+}
+
+void rxrpc_put_bundle(struct rxrpc_bundle *bundle)
+{
+ unsigned int d = bundle->debug_id;
+ bool dead;
+ int r;
+
+ dead = __refcount_dec_and_test(&bundle->ref, &r);
+
+ _debug("PUT B=%x %d", d, r - 1);
+ if (dead)
+ rxrpc_free_bundle(bundle);
+}
+
+/*
+ * Allocate a client connection.
+ */
+static struct rxrpc_connection *
+rxrpc_alloc_client_connection(struct rxrpc_bundle *bundle, gfp_t gfp)
+{
+ struct rxrpc_connection *conn;
+ struct rxrpc_net *rxnet = bundle->params.local->rxnet;
+ int ret;
+
+ _enter("");
+
+ conn = rxrpc_alloc_connection(gfp);
+ if (!conn) {
+ _leave(" = -ENOMEM");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ refcount_set(&conn->ref, 1);
+ conn->bundle = bundle;
+ conn->params = bundle->params;
+ conn->out_clientflag = RXRPC_CLIENT_INITIATED;
+ conn->state = RXRPC_CONN_CLIENT;
+ conn->service_id = conn->params.service_id;
+
+ ret = rxrpc_get_client_connection_id(conn, gfp);
+ if (ret < 0)
+ goto error_0;
+
+ ret = rxrpc_init_client_conn_security(conn);
+ if (ret < 0)
+ goto error_1;
+
+ 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_get_bundle(bundle);
+ rxrpc_get_peer(conn->params.peer);
+ rxrpc_get_local(conn->params.local);
+ key_get(conn->params.key);
+
+ trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_client,
+ refcount_read(&conn->ref),
+ __builtin_return_address(0));
+
+ atomic_inc(&rxnet->nr_client_conns);
+ trace_rxrpc_client(conn, -1, rxrpc_client_alloc);
+ _leave(" = %p", conn);
+ return conn;
+
+error_1:
+ rxrpc_put_client_connection_id(conn);
+error_0:
+ kfree(conn);
+ _leave(" = %d", ret);
+ return ERR_PTR(ret);
+}
+
+/*
+ * 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->params.local->rxnet;
+ if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags))
+ goto dont_reuse;
+
+ if (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(&rxrpc_client_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.
+ */
+static struct rxrpc_bundle *rxrpc_look_up_bundle(struct rxrpc_conn_parameters *cp,
+ gfp_t gfp)
+{
+ static atomic_t rxrpc_bundle_id;
+ struct rxrpc_bundle *bundle, *candidate;
+ struct rxrpc_local *local = cp->local;
+ struct rb_node *p, **pp, *parent;
+ long diff;
+
+ _enter("{%px,%x,%u,%u}",
+ cp->peer, key_serial(cp->key), cp->security_level, cp->upgrade);
+
+ if (cp->exclusive)
+ return rxrpc_alloc_bundle(cp, gfp);
+
+ /* 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) ((long)bundle->params.X - (long)cp->X)
+ diff = (cmp(peer) ?:
+ cmp(key) ?:
+ cmp(security_level) ?:
+ cmp(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(cp, gfp);
+ if (!candidate)
+ return NULL;
+
+ _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) ((long)bundle->params.X - (long)cp->X)
+ diff = (cmp(peer) ?:
+ cmp(key) ?:
+ cmp(security_level) ?:
+ cmp(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");
+ candidate->debug_id = atomic_inc_return(&rxrpc_bundle_id);
+ rb_link_node(&candidate->local_node, parent, pp);
+ rb_insert_color(&candidate->local_node, &local->client_bundles);
+ rxrpc_get_bundle(candidate);
+ spin_unlock(&local->client_bundles_lock);
+ _leave(" = %u [new]", candidate->debug_id);
+ return candidate;
+
+found_bundle_free:
+ rxrpc_free_bundle(candidate);
+found_bundle:
+ rxrpc_get_bundle(bundle);
+ atomic_inc(&bundle->active);
+ spin_unlock(&local->client_bundles_lock);
+ _leave(" = %u [found]", bundle->debug_id);
+ return bundle;
+}
+
+/*
+ * Create or find a client bundle to use for a call.
+ *
+ * If we return with a connection, the call will be on its waiting list. It's
+ * left to the caller to assign a channel and wake up the call.
+ */
+static struct rxrpc_bundle *rxrpc_prep_call(struct rxrpc_sock *rx,
+ struct rxrpc_call *call,
+ struct rxrpc_conn_parameters *cp,
+ struct sockaddr_rxrpc *srx,
+ gfp_t gfp)
+{
+ struct rxrpc_bundle *bundle;
+
+ _enter("{%d,%lx},", call->debug_id, call->user_call_ID);
+
+ cp->peer = rxrpc_lookup_peer(rx, cp->local, srx, gfp);
+ if (!cp->peer)
+ goto error;
+
+ call->cong_cwnd = cp->peer->cong_cwnd;
+ if (call->cong_cwnd >= call->cong_ssthresh)
+ call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
+ else
+ call->cong_mode = RXRPC_CALL_SLOW_START;
+ if (cp->upgrade)
+ __set_bit(RXRPC_CALL_UPGRADE, &call->flags);
+
+ /* Find the client connection bundle. */
+ bundle = rxrpc_look_up_bundle(cp, gfp);
+ if (!bundle)
+ goto error;
+
+ /* Get this call queued. Someone else may activate it whilst we're
+ * lining up a new connection, but that's fine.
+ */
+ spin_lock(&bundle->channel_lock);
+ list_add_tail(&call->chan_wait_link, &bundle->waiting_calls);
+ spin_unlock(&bundle->channel_lock);
+
+ _leave(" = [B=%x]", bundle->debug_id);
+ return bundle;
+
+error:
+ _leave(" = -ENOMEM");
+ return ERR_PTR(-ENOMEM);
+}
+
+/*
+ * Allocate a new connection and add it into a bundle.
+ */
+static void rxrpc_add_conn_to_bundle(struct rxrpc_bundle *bundle, gfp_t gfp)
+ __releases(bundle->channel_lock)
+{
+ struct rxrpc_connection *candidate = NULL, *old = NULL;
+ bool conflict;
+ int i;
+
+ _enter("");
+
+ conflict = bundle->alloc_conn;
+ if (!conflict)
+ bundle->alloc_conn = true;
+ spin_unlock(&bundle->channel_lock);
+ if (conflict) {
+ _leave(" [conf]");
+ return;
+ }
+
+ candidate = rxrpc_alloc_client_connection(bundle, gfp);
+
+ spin_lock(&bundle->channel_lock);
+ bundle->alloc_conn = false;
+
+ if (IS_ERR(candidate)) {
+ bundle->alloc_error = PTR_ERR(candidate);
+ spin_unlock(&bundle->channel_lock);
+ _leave(" [err %ld]", PTR_ERR(candidate));
+ return;
+ }
+
+ bundle->alloc_error = 0;
+
+ for (i = 0; i < ARRAY_SIZE(bundle->conns); i++) {
+ unsigned int shift = i * RXRPC_MAXCALLS;
+ int j;
+
+ old = bundle->conns[i];
+ if (!rxrpc_may_reuse_conn(old)) {
+ if (old)
+ trace_rxrpc_client(old, -1, rxrpc_client_replace);
+ candidate->bundle_shift = shift;
+ atomic_inc(&bundle->active);
+ bundle->conns[i] = candidate;
+ for (j = 0; j < RXRPC_MAXCALLS; j++)
+ set_bit(shift + j, &bundle->avail_chans);
+ candidate = NULL;
+ break;
+ }
+
+ old = NULL;
+ }
+
+ spin_unlock(&bundle->channel_lock);
+
+ if (candidate) {
+ _debug("discard C=%x", candidate->debug_id);
+ trace_rxrpc_client(candidate, -1, rxrpc_client_duplicate);
+ rxrpc_put_connection(candidate);
+ }
+
+ rxrpc_put_connection(old);
+ _leave("");
+}
+
+/*
+ * Add a connection to a bundle if there are no usable connections or we have
+ * connections waiting for extra capacity.
+ */
+static void rxrpc_maybe_add_conn(struct rxrpc_bundle *bundle, gfp_t gfp)
+{
+ struct rxrpc_call *call;
+ int i, usable;
+
+ _enter("");
+
+ spin_lock(&bundle->channel_lock);
+
+ /* 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++;
+
+ if (!usable && !list_empty(&bundle->waiting_calls)) {
+ call = list_first_entry(&bundle->waiting_calls,
+ struct rxrpc_call, chan_wait_link);
+ if (test_bit(RXRPC_CALL_UPGRADE, &call->flags))
+ bundle->try_upgrade = true;
+ }
+
+ if (!usable)
+ goto alloc_conn;
+
+ if (!bundle->avail_chans &&
+ !bundle->try_upgrade &&
+ !list_empty(&bundle->waiting_calls) &&
+ usable < ARRAY_SIZE(bundle->conns))
+ goto alloc_conn;
+
+ spin_unlock(&bundle->channel_lock);
+ _leave("");
+ return;
+
+alloc_conn:
+ return rxrpc_add_conn_to_bundle(bundle, gfp);
+}
+
+/*
+ * 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, chan_wait_link);
+ u32 call_id = chan->call_counter + 1;
+
+ _enter("C=%x,%u", conn->debug_id, channel);
+
+ 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);
+ list_del_init(&call->chan_wait_link);
+ call->peer = rxrpc_get_peer(conn->params.peer);
+ call->conn = rxrpc_get_connection(conn);
+ call->cid = conn->proto.cid | channel;
+ call->call_id = call_id;
+ call->security = conn->security;
+ call->security_ix = conn->security_ix;
+ call->service_id = conn->service_id;
+
+ trace_rxrpc_connect_call(call);
+ _net("CONNECT call %08x:%08x as call %d on conn %d",
+ call->cid, call->call_id, call->debug_id, conn->debug_id);
+
+ write_lock_bh(&call->state_lock);
+ call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
+ write_unlock_bh(&call->state_lock);
+
+ /* Paired with the read barrier in rxrpc_connect_call(). This orders
+ * cid and epoch in the connection wrt to call_id without the need to
+ * take the channel_lock.
+ *
+ * We provisionally assign a callNumber at this point, but we don't
+ * confirm it until the call is about to be exposed.
+ *
+ * TODO: Pair with a barrier in the data_ready handler when that looks
+ * at the call ID through a connection channel.
+ */
+ smp_wmb();
+
+ chan->call_id = call_id;
+ chan->call_debug_id = call->debug_id;
+ rcu_assign_pointer(chan->call, call);
+ wake_up(&call->waitq);
+}
+
+/*
+ * Remove a connection from the idle list if it's on it.
+ */
+static void rxrpc_unidle_conn(struct rxrpc_bundle *bundle, struct rxrpc_connection *conn)
+{
+ struct rxrpc_net *rxnet = bundle->params.local->rxnet;
+ bool drop_ref;
+
+ if (!list_empty(&conn->cache_link)) {
+ drop_ref = false;
+ spin_lock(&rxnet->client_conn_cache_lock);
+ if (!list_empty(&conn->cache_link)) {
+ list_del_init(&conn->cache_link);
+ drop_ref = true;
+ }
+ spin_unlock(&rxnet->client_conn_cache_lock);
+ if (drop_ref)
+ rxrpc_put_connection(conn);
+ }
+}
+
+/*
+ * Assign channels and callNumbers to waiting calls with channel_lock
+ * held by caller.
+ */
+static void rxrpc_activate_channels_locked(struct rxrpc_bundle *bundle)
+{
+ struct rxrpc_connection *conn;
+ unsigned long avail, mask;
+ unsigned int channel, slot;
+
+ 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(bundle, conn);
+
+ channel &= (RXRPC_MAXCALLS - 1);
+ conn->act_chans |= 1 << channel;
+ rxrpc_activate_one_channel(conn, channel);
+ }
+}
+
+/*
+ * Assign channels and callNumbers to waiting calls.
+ */
+static void rxrpc_activate_channels(struct rxrpc_bundle *bundle)
+{
+ _enter("B=%x", bundle->debug_id);
+
+ trace_rxrpc_client(NULL, -1, rxrpc_client_activate_chans);
+
+ if (!bundle->avail_chans)
+ return;
+
+ spin_lock(&bundle->channel_lock);
+ rxrpc_activate_channels_locked(bundle);
+ spin_unlock(&bundle->channel_lock);
+ _leave("");
+}
+
+/*
+ * Wait for a callNumber and a channel to be granted to a call.
+ */
+static int rxrpc_wait_for_channel(struct rxrpc_bundle *bundle,
+ struct rxrpc_call *call, gfp_t gfp)
+{
+ DECLARE_WAITQUEUE(myself, current);
+ int ret = 0;
+
+ _enter("%d", call->debug_id);
+
+ if (!gfpflags_allow_blocking(gfp)) {
+ rxrpc_maybe_add_conn(bundle, gfp);
+ rxrpc_activate_channels(bundle);
+ ret = bundle->alloc_error ?: -EAGAIN;
+ goto out;
+ }
+
+ add_wait_queue_exclusive(&call->waitq, &myself);
+ for (;;) {
+ rxrpc_maybe_add_conn(bundle, gfp);
+ rxrpc_activate_channels(bundle);
+ ret = bundle->alloc_error;
+ if (ret < 0)
+ break;
+
+ switch (call->interruptibility) {
+ case RXRPC_INTERRUPTIBLE:
+ case RXRPC_PREINTERRUPTIBLE:
+ set_current_state(TASK_INTERRUPTIBLE);
+ break;
+ case RXRPC_UNINTERRUPTIBLE:
+ default:
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ break;
+ }
+ if (READ_ONCE(call->state) != RXRPC_CALL_CLIENT_AWAIT_CONN)
+ break;
+ if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
+ call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
+ signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+ schedule();
+ }
+ remove_wait_queue(&call->waitq, &myself);
+ __set_current_state(TASK_RUNNING);
+
+out:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * find a connection for a call
+ * - called in process context with IRQs enabled
+ */
+int rxrpc_connect_call(struct rxrpc_sock *rx,
+ struct rxrpc_call *call,
+ struct rxrpc_conn_parameters *cp,
+ struct sockaddr_rxrpc *srx,
+ gfp_t gfp)
+{
+ struct rxrpc_bundle *bundle;
+ struct rxrpc_net *rxnet = cp->local->rxnet;
+ int ret = 0;
+
+ _enter("{%d,%lx},", call->debug_id, call->user_call_ID);
+
+ rxrpc_discard_expired_client_conns(&rxnet->client_conn_reaper);
+
+ bundle = rxrpc_prep_call(rx, call, cp, srx, gfp);
+ if (IS_ERR(bundle)) {
+ ret = PTR_ERR(bundle);
+ goto out;
+ }
+
+ if (call->state == RXRPC_CALL_CLIENT_AWAIT_CONN) {
+ ret = rxrpc_wait_for_channel(bundle, call, gfp);
+ if (ret < 0)
+ goto wait_failed;
+ }
+
+granted_channel:
+ /* Paired with the write barrier in rxrpc_activate_one_channel(). */
+ smp_rmb();
+
+out_put_bundle:
+ rxrpc_deactivate_bundle(bundle);
+ rxrpc_put_bundle(bundle);
+out:
+ _leave(" = %d", ret);
+ return ret;
+
+wait_failed:
+ spin_lock(&bundle->channel_lock);
+ list_del_init(&call->chan_wait_link);
+ spin_unlock(&bundle->channel_lock);
+
+ if (call->state != RXRPC_CALL_CLIENT_AWAIT_CONN) {
+ ret = 0;
+ goto granted_channel;
+ }
+
+ trace_rxrpc_client(call->conn, ret, rxrpc_client_chan_wait_failed);
+ rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
+ rxrpc_disconnect_client_call(bundle, call);
+ goto out_put_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);
+ }
+}
+
+/*
+ * Set the reap timer.
+ */
+static void rxrpc_set_client_reap_timer(struct rxrpc_net *rxnet)
+{
+ if (!rxnet->kill_all_client_conns) {
+ unsigned long now = jiffies;
+ unsigned long reap_at = now + rxrpc_conn_idle_client_expiry;
+
+ if (rxnet->live)
+ timer_reduce(&rxnet->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_net *rxnet = bundle->params.local->rxnet;
+ unsigned int channel;
+ bool may_reuse;
+ u32 cid;
+
+ _enter("c=%x", call->debug_id);
+
+ spin_lock(&bundle->channel_lock);
+ set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
+
+ /* 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->chan_wait_link);
+ goto out;
+ }
+
+ cid = call->cid;
+ channel = cid & RXRPC_CHANNELMASK;
+ chan = &conn->channels[channel];
+ trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect);
+
+ if (rcu_access_pointer(chan->call) != call) {
+ spin_unlock(&bundle->channel_lock);
+ BUG();
+ }
+
+ 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_locked(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);
+ goto out;
+ }
+
+ /* 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. */
+ rcu_assign_pointer(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);
+ spin_lock(&rxnet->client_conn_cache_lock);
+ list_move_tail(&conn->cache_link, &rxnet->idle_client_conns);
+ spin_unlock(&rxnet->client_conn_cache_lock);
+
+ rxrpc_set_client_reap_timer(rxnet);
+ }
+
+out:
+ spin_unlock(&bundle->channel_lock);
+ _leave("");
+ return;
+}
+
+/*
+ * Remove a connection from a bundle.
+ */
+static void rxrpc_unbundle_conn(struct rxrpc_connection *conn)
+{
+ struct rxrpc_bundle *bundle = conn->bundle;
+ unsigned int bindex;
+ bool need_drop = false;
+ int i;
+
+ _enter("C=%x", conn->debug_id);
+
+ if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
+ rxrpc_process_delayed_final_acks(conn, true);
+
+ spin_lock(&bundle->channel_lock);
+ 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);
+ need_drop = true;
+ }
+ spin_unlock(&bundle->channel_lock);
+
+ if (need_drop) {
+ rxrpc_deactivate_bundle(bundle);
+ rxrpc_put_connection(conn);
+ }
+}
+
+/*
+ * Drop the active count on a bundle.
+ */
+static void rxrpc_deactivate_bundle(struct rxrpc_bundle *bundle)
+{
+ struct rxrpc_local *local = bundle->params.local;
+ bool need_put = false;
+
+ if (atomic_dec_and_lock(&bundle->active, &local->client_bundles_lock)) {
+ if (!bundle->params.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);
+ }
+}
+
+/*
+ * Clean up a dead client connection.
+ */
+static void rxrpc_kill_client_conn(struct rxrpc_connection *conn)
+{
+ struct rxrpc_local *local = conn->params.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(conn);
+ rxrpc_kill_connection(conn);
+}
+
+/*
+ * Clean up a dead client connections.
+ */
+void rxrpc_put_client_conn(struct rxrpc_connection *conn)
+{
+ const void *here = __builtin_return_address(0);
+ unsigned int debug_id = conn->debug_id;
+ bool dead;
+ int r;
+
+ dead = __refcount_dec_and_test(&conn->ref, &r);
+ trace_rxrpc_conn(debug_id, rxrpc_conn_put_client, r - 1, here);
+ if (dead)
+ rxrpc_kill_client_conn(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 work_struct *work)
+{
+ struct rxrpc_connection *conn;
+ struct rxrpc_net *rxnet =
+ container_of(work, struct rxrpc_net, client_conn_reaper);
+ unsigned long expiry, conn_expires_at, now;
+ unsigned int nr_conns;
+
+ _enter("");
+
+ if (list_empty(&rxnet->idle_client_conns)) {
+ _leave(" [empty]");
+ return;
+ }
+
+ /* Don't double up on the discarding */
+ if (!spin_trylock(&rxnet->client_conn_discard_lock)) {
+ _leave(" [already]");
+ return;
+ }
+
+ /* 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(&rxnet->nr_client_conns);
+
+next:
+ spin_lock(&rxnet->client_conn_cache_lock);
+
+ if (list_empty(&rxnet->idle_client_conns))
+ goto out;
+
+ conn = list_entry(rxnet->idle_client_conns.next,
+ struct rxrpc_connection, cache_link);
+
+ if (!rxnet->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->params.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;
+ }
+
+ trace_rxrpc_client(conn, -1, rxrpc_client_discard);
+ list_del_init(&conn->cache_link);
+
+ spin_unlock(&rxnet->client_conn_cache_lock);
+
+ rxrpc_unbundle_conn(conn);
+ rxrpc_put_connection(conn); /* Drop the ->cache_link ref */
+
+ 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 (!rxnet->kill_all_client_conns)
+ timer_reduce(&rxnet->client_conn_reap_timer, conn_expires_at);
+
+out:
+ spin_unlock(&rxnet->client_conn_cache_lock);
+ spin_unlock(&rxnet->client_conn_discard_lock);
+ _leave("");
+}
+
+/*
+ * Preemptively destroy all the client connection records rather than waiting
+ * for them to time out
+ */
+void rxrpc_destroy_all_client_connections(struct rxrpc_net *rxnet)
+{
+ _enter("");
+
+ spin_lock(&rxnet->client_conn_cache_lock);
+ rxnet->kill_all_client_conns = true;
+ spin_unlock(&rxnet->client_conn_cache_lock);
+
+ del_timer_sync(&rxnet->client_conn_reap_timer);
+
+ if (!rxrpc_queue_work(&rxnet->client_conn_reaper))
+ _debug("destroy: queue failed");
+
+ _leave("");
+}
+
+/*
+ * Clean up the client connections on a local endpoint.
+ */
+void rxrpc_clean_up_local_conns(struct rxrpc_local *local)
+{
+ struct rxrpc_connection *conn, *tmp;
+ struct rxrpc_net *rxnet = local->rxnet;
+ LIST_HEAD(graveyard);
+
+ _enter("");
+
+ spin_lock(&rxnet->client_conn_cache_lock);
+
+ list_for_each_entry_safe(conn, tmp, &rxnet->idle_client_conns,
+ cache_link) {
+ if (conn->params.local == local) {
+ trace_rxrpc_client(conn, -1, rxrpc_client_discard);
+ list_move(&conn->cache_link, &graveyard);
+ }
+ }
+
+ spin_unlock(&rxnet->client_conn_cache_lock);
+
+ while (!list_empty(&graveyard)) {
+ conn = list_entry(graveyard.next,
+ struct rxrpc_connection, cache_link);
+ list_del_init(&conn->cache_link);
+ rxrpc_unbundle_conn(conn);
+ rxrpc_put_connection(conn);
+ }
+
+ _leave(" [culled]");
+}