diff options
Diffstat (limited to 'fs/ocfs2/cluster/tcp.c')
| -rw-r--r-- | fs/ocfs2/cluster/tcp.c | 1829 |
1 files changed, 1829 insertions, 0 deletions
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c new file mode 100644 index 000000000000..35d92c01a972 --- /dev/null +++ b/fs/ocfs2/cluster/tcp.c @@ -0,0 +1,1829 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * Copyright (C) 2004 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + * ---- + * + * Callers for this were originally written against a very simple synchronus + * API. This implementation reflects those simple callers. Some day I'm sure + * we'll need to move to a more robust posting/callback mechanism. + * + * Transmit calls pass in kernel virtual addresses and block copying this into + * the socket's tx buffers via a usual blocking sendmsg. They'll block waiting + * for a failed socket to timeout. TX callers can also pass in a poniter to an + * 'int' which gets filled with an errno off the wire in response to the + * message they send. + * + * Handlers for unsolicited messages are registered. Each socket has a page + * that incoming data is copied into. First the header, then the data. + * Handlers are called from only one thread with a reference to this per-socket + * page. This page is destroyed after the handler call, so it can't be + * referenced beyond the call. Handlers may block but are discouraged from + * doing so. + * + * Any framing errors (bad magic, large payload lengths) close a connection. + * + * Our sock_container holds the state we associate with a socket. It's current + * framing state is held there as well as the refcounting we do around when it + * is safe to tear down the socket. The socket is only finally torn down from + * the container when the container loses all of its references -- so as long + * as you hold a ref on the container you can trust that the socket is valid + * for use with kernel socket APIs. + * + * Connections are initiated between a pair of nodes when the node with the + * higher node number gets a heartbeat callback which indicates that the lower + * numbered node has started heartbeating. The lower numbered node is passive + * and only accepts the connection if the higher numbered node is heartbeating. + */ + +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/slab.h> +#include <linux/idr.h> +#include <linux/kref.h> +#include <net/tcp.h> + +#include <asm/uaccess.h> + +#include "heartbeat.h" +#include "tcp.h" +#include "nodemanager.h" +#define MLOG_MASK_PREFIX ML_TCP +#include "masklog.h" +#include "quorum.h" + +#include "tcp_internal.h" + +/* + * The linux network stack isn't sparse endian clean.. It has macros like + * ntohs() which perform the endian checks and structs like sockaddr_in + * which aren't annotated. So __force is found here to get the build + * clean. When they emerge from the dark ages and annotate the code + * we can remove these. + */ + +#define SC_NODEF_FMT "node %s (num %u) at %u.%u.%u.%u:%u" +#define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num, \ + NIPQUAD(sc->sc_node->nd_ipv4_address), \ + ntohs(sc->sc_node->nd_ipv4_port) + +/* + * In the following two log macros, the whitespace after the ',' just + * before ##args is intentional. Otherwise, gcc 2.95 will eat the + * previous token if args expands to nothing. + */ +#define msglog(hdr, fmt, args...) do { \ + typeof(hdr) __hdr = (hdr); \ + mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d " \ + "key %08x num %u] " fmt, \ + be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len), \ + be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status), \ + be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key), \ + be32_to_cpu(__hdr->msg_num) , ##args); \ +} while (0) + +#define sclog(sc, fmt, args...) do { \ + typeof(sc) __sc = (sc); \ + mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p " \ + "pg_off %zu] " fmt, __sc, \ + atomic_read(&__sc->sc_kref.refcount), __sc->sc_sock, \ + __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off , \ + ##args); \ +} while (0) + +static rwlock_t o2net_handler_lock = RW_LOCK_UNLOCKED; +static struct rb_root o2net_handler_tree = RB_ROOT; + +static struct o2net_node o2net_nodes[O2NM_MAX_NODES]; + +/* XXX someday we'll need better accounting */ +static struct socket *o2net_listen_sock = NULL; + +/* + * listen work is only queued by the listening socket callbacks on the + * o2net_wq. teardown detaches the callbacks before destroying the workqueue. + * quorum work is queued as sock containers are shutdown.. stop_listening + * tears down all the node's sock containers, preventing future shutdowns + * and queued quroum work, before canceling delayed quorum work and + * destroying the work queue. + */ +static struct workqueue_struct *o2net_wq; +static struct work_struct o2net_listen_work; + +static struct o2hb_callback_func o2net_hb_up, o2net_hb_down; +#define O2NET_HB_PRI 0x1 + +static struct o2net_handshake *o2net_hand; +static struct o2net_msg *o2net_keep_req, *o2net_keep_resp; + +static int o2net_sys_err_translations[O2NET_ERR_MAX] = + {[O2NET_ERR_NONE] = 0, + [O2NET_ERR_NO_HNDLR] = -ENOPROTOOPT, + [O2NET_ERR_OVERFLOW] = -EOVERFLOW, + [O2NET_ERR_DIED] = -EHOSTDOWN,}; + +/* can't quite avoid *all* internal declarations :/ */ +static void o2net_sc_connect_completed(void *arg); +static void o2net_rx_until_empty(void *arg); +static void o2net_shutdown_sc(void *arg); +static void o2net_listen_data_ready(struct sock *sk, int bytes); +static void o2net_sc_send_keep_req(void *arg); +static void o2net_idle_timer(unsigned long data); +static void o2net_sc_postpone_idle(struct o2net_sock_container *sc); + +static inline int o2net_sys_err_to_errno(enum o2net_system_error err) +{ + int trans; + BUG_ON(err >= O2NET_ERR_MAX); + trans = o2net_sys_err_translations[err]; + + /* Just in case we mess up the translation table above */ + BUG_ON(err != O2NET_ERR_NONE && trans == 0); + return trans; +} + +static struct o2net_node * o2net_nn_from_num(u8 node_num) +{ + BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes)); + return &o2net_nodes[node_num]; +} + +static u8 o2net_num_from_nn(struct o2net_node *nn) +{ + BUG_ON(nn == NULL); + return nn - o2net_nodes; +} + +/* ------------------------------------------------------------ */ + +static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw) +{ + int ret = 0; + + do { + if (!idr_pre_get(&nn->nn_status_idr, GFP_ATOMIC)) { + ret = -EAGAIN; + break; + } + spin_lock(&nn->nn_lock); + ret = idr_get_new(&nn->nn_status_idr, nsw, &nsw->ns_id); + if (ret == 0) + list_add_tail(&nsw->ns_node_item, + &nn->nn_status_list); + spin_unlock(&nn->nn_lock); + } while (ret == -EAGAIN); + + if (ret == 0) { + init_waitqueue_head(&nsw->ns_wq); + nsw->ns_sys_status = O2NET_ERR_NONE; + nsw->ns_status = 0; + } + + return ret; +} + +static void o2net_complete_nsw_locked(struct o2net_node *nn, + struct o2net_status_wait *nsw, + enum o2net_system_error sys_status, + s32 status) +{ + assert_spin_locked(&nn->nn_lock); + + if (!list_empty(&nsw->ns_node_item)) { + list_del_init(&nsw->ns_node_item); + nsw->ns_sys_status = sys_status; + nsw->ns_status = status; + idr_remove(&nn->nn_status_idr, nsw->ns_id); + wake_up(&nsw->ns_wq); + } +} + +static void o2net_complete_nsw(struct o2net_node *nn, + struct o2net_status_wait *nsw, + u64 id, enum o2net_system_error sys_status, + s32 status) +{ + spin_lock(&nn->nn_lock); + if (nsw == NULL) { + if (id > INT_MAX) + goto out; + + nsw = idr_find(&nn->nn_status_idr, id); + if (nsw == NULL) + goto out; + } + + o2net_complete_nsw_locked(nn, nsw, sys_status, status); + +out: + spin_unlock(&nn->nn_lock); + return; +} + +static void o2net_complete_nodes_nsw(struct o2net_node *nn) +{ + struct list_head *iter, *tmp; + unsigned int num_kills = 0; + struct o2net_status_wait *nsw; + + assert_spin_locked(&nn->nn_lock); + + list_for_each_safe(iter, tmp, &nn->nn_status_list) { + nsw = list_entry(iter, struct o2net_status_wait, ns_node_item); + o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0); + num_kills++; + } + + mlog(0, "completed %d messages for node %u\n", num_kills, + o2net_num_from_nn(nn)); +} + +static int o2net_nsw_completed(struct o2net_node *nn, + struct o2net_status_wait *nsw) +{ + int completed; + spin_lock(&nn->nn_lock); + completed = list_empty(&nsw->ns_node_item); + spin_unlock(&nn->nn_lock); + return completed; +} + +/* ------------------------------------------------------------ */ + +static void sc_kref_release(struct kref *kref) +{ + struct o2net_sock_container *sc = container_of(kref, + struct o2net_sock_container, sc_kref); + sclog(sc, "releasing\n"); + + if (sc->sc_sock) { + sock_release(sc->sc_sock); + sc->sc_sock = NULL; + } + + o2nm_node_put(sc->sc_node); + sc->sc_node = NULL; + + kfree(sc); +} + +static void sc_put(struct o2net_sock_container *sc) +{ + sclog(sc, "put\n"); + kref_put(&sc->sc_kref, sc_kref_release); +} +static void sc_get(struct o2net_sock_container *sc) +{ + sclog(sc, "get\n"); + kref_get(&sc->sc_kref); +} +static struct o2net_sock_container *sc_alloc(struct o2nm_node *node) +{ + struct o2net_sock_container *sc, *ret = NULL; + struct page *page = NULL; + + page = alloc_page(GFP_NOFS); + sc = kcalloc(1, sizeof(*sc), GFP_NOFS); + if (sc == NULL || page == NULL) + goto out; + + kref_init(&sc->sc_kref); + o2nm_node_get(node); + sc->sc_node = node; + + INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed, sc); + INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty, sc); + INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc, sc); + INIT_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req, sc); + + init_timer(&sc->sc_idle_timeout); + sc->sc_idle_timeout.function = o2net_idle_timer; + sc->sc_idle_timeout.data = (unsigned long)sc; + + sclog(sc, "alloced\n"); + + ret = sc; + sc->sc_page = page; + sc = NULL; + page = NULL; + +out: + if (page) + __free_page(page); + kfree(sc); + + return ret; +} + +/* ------------------------------------------------------------ */ + +static void o2net_sc_queue_work(struct o2net_sock_container *sc, + struct work_struct *work) +{ + sc_get(sc); + if (!queue_work(o2net_wq, work)) + sc_put(sc); +} +static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc, + struct work_struct *work, + int delay) +{ + sc_get(sc); + if (!queue_delayed_work(o2net_wq, work, delay)) + sc_put(sc); +} +static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc, + struct work_struct *work) +{ + if (cancel_delayed_work(work)) + sc_put(sc); +} + +static void o2net_set_nn_state(struct o2net_node *nn, + struct o2net_sock_container *sc, + unsigned valid, int err) +{ + int was_valid = nn->nn_sc_valid; + int was_err = nn->nn_persistent_error; + struct o2net_sock_container *old_sc = nn->nn_sc; + + assert_spin_locked(&nn->nn_lock); + + /* the node num comparison and single connect/accept path should stop + * an non-null sc from being overwritten with another */ + BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc); + mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid); + mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc); + + /* we won't reconnect after our valid conn goes away for + * this hb iteration.. here so it shows up in the logs */ + if (was_valid && !valid && err == 0) + err = -ENOTCONN; + + mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n", + o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid, + nn->nn_persistent_error, err); + + nn->nn_sc = sc; + nn->nn_sc_valid = valid ? 1 : 0; + nn->nn_persistent_error = err; + + /* mirrors o2net_tx_can_proceed() */ + if (nn->nn_persistent_error || nn->nn_sc_valid) + wake_up(&nn->nn_sc_wq); + + if (!was_err && nn->nn_persistent_error) { + o2quo_conn_err(o2net_num_from_nn(nn)); + queue_delayed_work(o2net_wq, &nn->nn_still_up, + msecs_to_jiffies(O2NET_QUORUM_DELAY_MS)); + } + + if (was_valid && !valid) { + mlog(ML_NOTICE, "no longer connected to " SC_NODEF_FMT "\n", + SC_NODEF_ARGS(old_sc)); + o2net_complete_nodes_nsw(nn); + } + + if (!was_valid && valid) { + o2quo_conn_up(o2net_num_from_nn(nn)); + /* this is a bit of a hack. we only try reconnecting + * when heartbeating starts until we get a connection. + * if that connection then dies we don't try reconnecting. + * the only way to start connecting again is to down + * heartbeat and bring it back up. */ + cancel_delayed_work(&nn->nn_connect_expired); + mlog(ML_NOTICE, "%s " SC_NODEF_FMT "\n", + o2nm_this_node() > sc->sc_node->nd_num ? + "connected to" : "accepted connection from", + SC_NODEF_ARGS(sc)); + } + + /* trigger the connecting worker func as long as we're not valid, + * it will back off if it shouldn't connect. This can be called + * from node config teardown and so needs to be careful about + * the work queue actually being up. */ + if (!valid && o2net_wq) { + unsigned long delay; + /* delay if we're withing a RECONNECT_DELAY of the + * last attempt */ + delay = (nn->nn_last_connect_attempt + + msecs_to_jiffies(O2NET_RECONNECT_DELAY_MS)) + - jiffies; + if (delay > msecs_to_jiffies(O2NET_RECONNECT_DELAY_MS)) + delay = 0; + mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay); + queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay); + } + + /* keep track of the nn's sc ref for the caller */ + if ((old_sc == NULL) && sc) + sc_get(sc); + if (old_sc && (old_sc != sc)) { + o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work); + sc_put(old_sc); + } +} + +/* see o2net_register_callbacks() */ +static void o2net_data_ready(struct sock *sk, int bytes) +{ + void (*ready)(struct sock *sk, int bytes); + + read_lock(&sk->sk_callback_lock); + if (sk->sk_user_data) { + struct o2net_sock_container *sc = sk->sk_user_data; + sclog(sc, "data_ready hit\n"); + do_gettimeofday(&sc->sc_tv_data_ready); + o2net_sc_queue_work(sc, &sc->sc_rx_work); + ready = sc->sc_data_ready; + } else { + ready = sk->sk_data_ready; + } + read_unlock(&sk->sk_callback_lock); + + ready(sk, bytes); +} + +/* see o2net_register_callbacks() */ +static void o2net_state_change(struct sock *sk) +{ + void (*state_change)(struct sock *sk); + struct o2net_sock_container *sc; + + read_lock(&sk->sk_callback_lock); + sc = sk->sk_user_data; + if (sc == NULL) { + state_change = sk->sk_state_change; + goto out; + } + + sclog(sc, "state_change to %d\n", sk->sk_state); + + state_change = sc->sc_state_change; + + switch(sk->sk_state) { + /* ignore connecting sockets as they make progress */ + case TCP_SYN_SENT: + case TCP_SYN_RECV: + break; + case TCP_ESTABLISHED: + o2net_sc_queue_work(sc, &sc->sc_connect_work); + break; + default: + o2net_sc_queue_work(sc, &sc->sc_shutdown_work); + break; + } +out: + read_unlock(&sk->sk_callback_lock); + state_change(sk); +} + +/* + * we register callbacks so we can queue work on events before calling + * the original callbacks. our callbacks our careful to test user_data + * to discover when they've reaced with o2net_unregister_callbacks(). + */ +static void o2net_register_callbacks(struct sock *sk, + struct o2net_sock_container *sc) +{ + write_lock_bh(&sk->sk_callback_lock); + + /* accepted sockets inherit the old listen socket data ready */ + if (sk->sk_data_ready == o2net_listen_data_ready) { + sk->sk_data_ready = sk->sk_user_data; + sk->sk_user_data = NULL; + } + + BUG_ON(sk->sk_user_data != NULL); + sk->sk_user_data = sc; + sc_get(sc); + + sc->sc_data_ready = sk->sk_data_ready; + sc->sc_state_change = sk->sk_state_change; + sk->sk_data_ready = o2net_data_ready; + sk->sk_state_change = o2net_state_change; + + write_unlock_bh(&sk->sk_callback_lock); +} + +static int o2net_unregister_callbacks(struct sock *sk, + struct o2net_sock_container *sc) +{ + int ret = 0; + + write_lock_bh(&sk->sk_callback_lock); + if (sk->sk_user_data == sc) { + ret = 1; + sk->sk_user_data = NULL; + sk->sk_data_ready = sc->sc_data_ready; + sk->sk_state_change = sc->sc_state_change; + } + write_unlock_bh(&sk->sk_callback_lock); + + return ret; +} + +/* + * this is a little helper that is called by callers who have seen a problem + * with an sc and want to detach it from the nn if someone already hasn't beat + * them to it. if an error is given then the shutdown will be persistent + * and pending transmits will be canceled. + */ +static void o2net_ensure_shutdown(struct o2net_node *nn, + struct o2net_sock_container *sc, + int err) +{ + spin_lock(&nn->nn_lock); + if (nn->nn_sc == sc) + o2net_set_nn_state(nn, NULL, 0, err); + spin_unlock(&nn->nn_lock); +} + +/* + * This work queue function performs the blocking parts of socket shutdown. A + * few paths lead here. set_nn_state will trigger this callback if it sees an + * sc detached from the nn. state_change will also trigger this callback + * directly when it sees errors. In that case we need to call set_nn_state + * ourselves as state_change couldn't get the nn_lock and call set_nn_state + * itself. + */ +static void o2net_shutdown_sc(void *arg) +{ + struct o2net_sock_container *sc = arg; + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + + sclog(sc, "shutting down\n"); + + /* drop the callbacks ref and call shutdown only once */ + if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) { + /* we shouldn't flush as we're in the thread, the + * races with pending sc work structs are harmless */ + del_timer_sync(&sc->sc_idle_timeout); + o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work); + sc_put(sc); + sc->sc_sock->ops->shutdown(sc->sc_sock, + RCV_SHUTDOWN|SEND_SHUTDOWN); + } + + /* not fatal so failed connects before the other guy has our + * heartbeat can be retried */ + o2net_ensure_shutdown(nn, sc, 0); + sc_put(sc); +} + +/* ------------------------------------------------------------ */ + +static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type, + u32 key) +{ + int ret = memcmp(&nmh->nh_key, &key, sizeof(key)); + + if (ret == 0) + ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type)); + + return ret; +} + +static struct o2net_msg_handler * +o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p, + struct rb_node **ret_parent) +{ + struct rb_node **p = &o2net_handler_tree.rb_node; + struct rb_node *parent = NULL; + struct o2net_msg_handler *nmh, *ret = NULL; + int cmp; + + while (*p) { + parent = *p; + nmh = rb_entry(parent, struct o2net_msg_handler, nh_node); + cmp = o2net_handler_cmp(nmh, msg_type, key); + + if (cmp < 0) + p = &(*p)->rb_left; + else if (cmp > 0) + p = &(*p)->rb_right; + else { + ret = nmh; + break; + } + } + + if (ret_p != NULL) + *ret_p = p; + if (ret_parent != NULL) + *ret_parent = parent; + + return ret; +} + +static void o2net_handler_kref_release(struct kref *kref) +{ + struct o2net_msg_handler *nmh; + nmh = container_of(kref, struct o2net_msg_handler, nh_kref); + + kfree(nmh); +} + +static void o2net_handler_put(struct o2net_msg_handler *nmh) +{ + kref_put(&nmh->nh_kref, o2net_handler_kref_release); +} + +/* max_len is protection for the handler func. incoming messages won't + * be given to the handler if their payload is longer than the max. */ +int o2net_register_handler(u32 msg_type, u32 key, u32 max_len, + o2net_msg_handler_func *func, void *data, + struct list_head *unreg_list) +{ + struct o2net_msg_handler *nmh = NULL; + struct rb_node **p, *parent; + int ret = 0; + + if (max_len > O2NET_MAX_PAYLOAD_BYTES) { + mlog(0, "max_len for message handler out of range: %u\n", + max_len); + ret = -EINVAL; + goto out; + } + + if (!msg_type) { + mlog(0, "no message type provided: %u, %p\n", msg_type, func); + ret = -EINVAL; + goto out; + + } + if (!func) { + mlog(0, "no message handler provided: %u, %p\n", + msg_type, func); + ret = -EINVAL; + goto out; + } + + nmh = kcalloc(1, sizeof(struct o2net_msg_handler), GFP_NOFS); + if (nmh == NULL) { + ret = -ENOMEM; + goto out; + } + + nmh->nh_func = func; + nmh->nh_func_data = data; + nmh->nh_msg_type = msg_type; + nmh->nh_max_len = max_len; + nmh->nh_key = key; + /* the tree and list get this ref.. they're both removed in + * unregister when this ref is dropped */ + kref_init(&nmh->nh_kref); + INIT_LIST_HEAD(&nmh->nh_unregister_item); + + write_lock(&o2net_handler_lock); + if (o2net_handler_tree_lookup(msg_type, key, &p, &parent)) + ret = -EEXIST; + else { + rb_link_node(&nmh->nh_node, parent, p); + rb_insert_color(&nmh->nh_node, &o2net_handler_tree); + list_add_tail(&nmh->nh_unregister_item, unreg_list); + + mlog(ML_TCP, "registered handler func %p type %u key %08x\n", + func, msg_type, key); + /* we've had some trouble with handlers seemingly vanishing. */ + mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p, + &parent) == NULL, + "couldn't find handler we *just* registerd " + "for type %u key %08x\n", msg_type, key); + } + write_unlock(&o2net_handler_lock); + if (ret) + goto out; + +out: + if (ret) + kfree(nmh); + + return ret; +} +EXPORT_SYMBOL_GPL(o2net_register_handler); + +void o2net_unregister_handler_list(struct list_head *list) +{ + struct list_head *pos, *n; + struct o2net_msg_handler *nmh; + + write_lock(&o2net_handler_lock); + list_for_each_safe(pos, n, list) { + nmh = list_entry(pos, struct o2net_msg_handler, + nh_unregister_item); + mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n", + nmh->nh_func, nmh->nh_msg_type, nmh->nh_key); + rb_erase(&nmh->nh_node, &o2net_handler_tree); + list_del_init(&nmh->nh_unregister_item); + kref_put(&nmh->nh_kref, o2net_handler_kref_release); + } + write_unlock(&o2net_handler_lock); +} +EXPORT_SYMBOL_GPL(o2net_unregister_handler_list); + +static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key) +{ + struct o2net_msg_handler *nmh; + + read_lock(&o2net_handler_lock); + nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL); + if (nmh) + kref_get(&nmh->nh_kref); + read_unlock(&o2net_handler_lock); + + return nmh; +} + +/* ------------------------------------------------------------ */ + +static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len) +{ + int ret; + mm_segment_t oldfs; + struct kvec vec = { + .iov_len = len, + .iov_base = data, + }; + struct msghdr msg = { + .msg_iovlen = 1, + .msg_iov = (struct iovec *)&vec, + .msg_flags = MSG_DONTWAIT, + }; + + oldfs = get_fs(); + set_fs(get_ds()); + ret = sock_recvmsg(sock, &msg, len, msg.msg_flags); + set_fs(oldfs); + + return ret; +} + +static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec, + size_t veclen, size_t total) +{ + int ret; + mm_segment_t oldfs; + struct msghdr msg = { + .msg_iov = (struct iovec *)vec, + .msg_iovlen = veclen, + }; + + if (sock == NULL) { + ret = -EINVAL; + goto out; + } + + oldfs = get_fs(); + set_fs(get_ds()); + ret = sock_sendmsg(sock, &msg, total); + set_fs(oldfs); + if (ret != total) { + mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret, + total); + if (ret >= 0) + ret = -EPIPE; /* should be smarter, I bet */ + goto out; + } + + ret = 0; +out: + if (ret < 0) + mlog(0, "returning error: %d\n", ret); + return ret; +} + +static void o2net_sendpage(struct o2net_sock_container *sc, + void *kmalloced_virt, + size_t size) +{ + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + ssize_t ret; + + + ret = sc->sc_sock->ops->sendpage(sc->sc_sock, + virt_to_page(kmalloced_virt), + (long)kmalloced_virt & ~PAGE_MASK, + size, MSG_DONTWAIT); + if (ret != size) { + mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT + " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret); + o2net_ensure_shutdown(nn, sc, 0); + } +} + +static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key) +{ + memset(msg, 0, sizeof(struct o2net_msg)); + msg->magic = cpu_to_be16(O2NET_MSG_MAGIC); + msg->data_len = cpu_to_be16(data_len); + msg->msg_type = cpu_to_be16(msg_type); + msg->sys_status = cpu_to_be32(O2NET_ERR_NONE); + msg->status = 0; + msg->key = cpu_to_be32(key); +} + +static int o2net_tx_can_proceed(struct o2net_node *nn, + struct o2net_sock_container **sc_ret, + int *error) +{ + int ret = 0; + + spin_lock(&nn->nn_lock); + if (nn->nn_persistent_error) { + ret = 1; + *sc_ret = NULL; + *error = nn->nn_persistent_error; + } else if (nn->nn_sc_valid) { + kref_get(&nn->nn_sc->sc_kref); + + ret = 1; + *sc_ret = nn->nn_sc; + *error = 0; + } + spin_unlock(&nn->nn_lock); + + return ret; +} + +int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec, + size_t caller_veclen, u8 target_node, int *status) +{ + int ret, error = 0; + struct o2net_msg *msg = NULL; + size_t veclen, caller_bytes = 0; + struct kvec *vec = NULL; + struct o2net_sock_container *sc = NULL; + struct o2net_node *nn = o2net_nn_from_num(target_node); + struct o2net_status_wait nsw = { + .ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item), + }; + + if (o2net_wq == NULL) { + mlog(0, "attempt to tx without o2netd running\n"); + ret = -ESRCH; + goto out; + } + + if (caller_veclen == 0) { + mlog(0, "bad kvec array length\n"); + ret = -EINVAL; + goto out; + } + + caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen); + if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) { + mlog(0, "total payload len %zu too large\n", caller_bytes); + ret = -EINVAL; + goto out; + } + + if (target_node == o2nm_this_node()) { + ret = -ELOOP; + goto out; + } + + ret = wait_event_interruptible(nn->nn_sc_wq, + o2net_tx_can_proceed(nn, &sc, &error)); + if (!ret && error) + ret = error; + if (ret) + goto out; + + veclen = caller_veclen + 1; + vec = kmalloc(sizeof(struct kvec) * veclen, GFP_ATOMIC); + if (vec == NULL) { + mlog(0, "failed to %zu element kvec!\n", veclen); + ret = -ENOMEM; + goto out; + } + + msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC); + if (!msg) { + mlog(0, "failed to allocate a o2net_msg!\n"); + ret = -ENOMEM; + goto out; + } + + o2net_init_msg(msg, caller_bytes, msg_type, key); + + vec[0].iov_len = sizeof(struct o2net_msg); + vec[0].iov_base = msg; + memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec)); + + ret = o2net_prep_nsw(nn, &nsw); + if (ret) + goto out; + + msg->msg_num = cpu_to_be32(nsw.ns_id); + + /* finally, convert the message header to network byte-order + * and send */ + ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen, + sizeof(struct o2net_msg) + caller_bytes); + msglog(msg, "sending returned %d\n", ret); + if (ret < 0) { + mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret); + goto out; + } + + /* wait on other node's handler */ + wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw)); + + /* Note that we avoid overwriting the callers status return + * variable if a system error was reported on the other + * side. Callers beware. */ + ret = o2net_sys_err_to_errno(nsw.ns_sys_status); + if (status && !ret) + *status = nsw.ns_status; + + mlog(0, "woken, returning system status %d, user status %d\n", + ret, nsw.ns_status); +out: + if (sc) + sc_put(sc); + if (vec) + kfree(vec); + if (msg) + kfree(msg); + o2net_complete_nsw(nn, &nsw, 0, 0, 0); + return ret; +} +EXPORT_SYMBOL_GPL(o2net_send_message_vec); + +int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len, + u8 target_node, int *status) +{ + struct kvec vec = { + .iov_base = data, + .iov_len = len, + }; + return o2net_send_message_vec(msg_type, key, &vec, 1, + target_node, status); +} +EXPORT_SYMBOL_GPL(o2net_send_message); + +static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr, + enum o2net_system_error syserr, int err) +{ + struct kvec vec = { + .iov_base = hdr, + .iov_len = sizeof(struct o2net_msg), + }; + + BUG_ON(syserr >= O2NET_ERR_MAX); + + /* leave other fields intact from the incoming message, msg_num + * in particular */ + hdr->sys_status = cpu_to_be32(syserr); + hdr->status = cpu_to_be32(err); + hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC); // twiddle the magic + hdr->data_len = 0; + + msglog(hdr, "about to send status magic %d\n", err); + /* hdr has been in host byteorder this whole time */ + return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg)); +} + +/* this returns -errno if the header was unknown or too large, etc. + * after this is called the buffer us reused for the next message */ +static int o2net_process_message(struct o2net_sock_container *sc, + struct o2net_msg *hdr) +{ + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + int ret = 0, handler_status; + enum o2net_system_error syserr; + struct o2net_msg_handler *nmh = NULL; + + msglog(hdr, "processing message\n"); + + o2net_sc_postpone_idle(sc); + + switch(be16_to_cpu(hdr->magic)) { + case O2NET_MSG_STATUS_MAGIC: + /* special type for returning message status */ + o2net_complete_nsw(nn, NULL, + be32_to_cpu(hdr->msg_num), + be32_to_cpu(hdr->sys_status), + be32_to_cpu(hdr->status)); + goto out; + case O2NET_MSG_KEEP_REQ_MAGIC: + o2net_sendpage(sc, o2net_keep_resp, + sizeof(*o2net_keep_resp)); + goto out; + case O2NET_MSG_KEEP_RESP_MAGIC: + goto out; + case O2NET_MSG_MAGIC: + break; + default: + msglog(hdr, "bad magic\n"); + ret = -EINVAL; + goto out; + break; + } + + /* find a handler for it */ + handler_status = 0; + nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type), + be32_to_cpu(hdr->key)); + if (!nmh) { + mlog(ML_TCP, "couldn't find handler for type %u key %08x\n", + be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key)); + syserr = O2NET_ERR_NO_HNDLR; + goto out_respond; + } + + syserr = O2NET_ERR_NONE; + + if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len) + syserr = O2NET_ERR_OVERFLOW; + + if (syserr != O2NET_ERR_NONE) + goto out_respond; + + do_gettimeofday(&sc->sc_tv_func_start); + sc->sc_msg_key = be32_to_cpu(hdr->key); + sc->sc_msg_type = be16_to_cpu(hdr->msg_type); + handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) + + be16_to_cpu(hdr->data_len), + nmh->nh_func_data); + do_gettimeofday(&sc->sc_tv_func_stop); + +out_respond: + /* this destroys the hdr, so don't use it after this */ + ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr, + handler_status); + hdr = NULL; + mlog(0, "sending handler status %d, syserr %d returned %d\n", + handler_status, syserr, ret); + +out: + if (nmh) + o2net_handler_put(nmh); + return ret; +} + +static int o2net_check_handshake(struct o2net_sock_container *sc) +{ + struct o2net_handshake *hand = page_address(sc->sc_page); + struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num); + + if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) { + mlog(ML_NOTICE, SC_NODEF_FMT " advertised net protocol " + "version %llu but %llu is required, disconnecting\n", + SC_NODEF_ARGS(sc), + (unsigned long long)be64_to_cpu(hand->protocol_version), + O2NET_PROTOCOL_VERSION); + + /* don't bother reconnecting if its the wrong version. */ + o2net_ensure_shutdown(nn, sc, -ENOTCONN); + return -1; + } + + sc->sc_handshake_ok = 1; + + spin_lock(&nn->nn_lock); + /* set valid and queue the idle timers only if it hasn't been + * shut down already */ + if (nn->nn_sc == sc) { + o2net_sc_postpone_idle(sc); + o2net_set_nn_state(nn, sc, 1, 0); + } + spin_unlock(&nn->nn_lock); + + /* shift everything up as though it wasn't there */ + sc->sc_page_off -= sizeof(struct o2net_handshake); + if (sc->sc_page_off) + memmove(hand, hand + 1, sc->sc_page_off); + + return 0; +} + +/* this demuxes the queued rx bytes into header or payload bits and calls + * handlers as each full message is read off the socket. it returns -error, + * == 0 eof, or > 0 for progress made.*/ +static int o2net_advance_rx(struct o2net_sock_container *sc) +{ + struct o2net_msg *hdr; + int ret = 0; + void *data; + size_t datalen; + + sclog(sc, "receiving\n"); + do_gettimeofday(&sc->sc_tv_advance_start); + + /* do we need more header? */ + if (sc->sc_page_off < sizeof(struct o2net_msg)) { + data = page_address(sc->sc_page) + sc->sc_page_off; + datalen = sizeof(struct o2net_msg) - sc->sc_page_off; + ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen); + if (ret > 0) { + sc->sc_page_off += ret; + + /* this working relies on the handshake being + * smaller than the normal message header */ + if (sc->sc_page_off >= sizeof(struct o2net_handshake)&& + !sc->sc_handshake_ok |