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linux/fs/ocfs2/cluster/tcp.c
Dan Carpenter e6d9f86d6b ocfs2: o2net: silence uninitialized variable warning 
Smatch complains that, if o2net_tx_can_proceed() returns false, then "sc"
and "ret" are uninialized or maybe we are re-using the data from previous
iteration.  I do not know if we can hit this bug in real life but checking
the return value is harmless and we may as well silence the static checker
warning.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:29 -08:00

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/* -*- 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 <linux/net.h>
#include <linux/export.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"
#define SC_NODEF_FMT "node %s (num %u) at %pI4:%u"
#define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num, \
&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 DEFINE_RWLOCK(o2net_handler_lock);
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;
/*
* 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(struct work_struct *work);
static void o2net_rx_until_empty(struct work_struct *work);
static void o2net_shutdown_sc(struct work_struct *work);
static void o2net_listen_data_ready(struct sock *sk);
static void o2net_sc_send_keep_req(struct work_struct *work);
static void o2net_idle_timer(unsigned long data);
static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
#ifdef CONFIG_DEBUG_FS
static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
u32 msgkey, struct task_struct *task, u8 node)
{
INIT_LIST_HEAD(&nst->st_net_debug_item);
nst->st_task = task;
nst->st_msg_type = msgtype;
nst->st_msg_key = msgkey;
nst->st_node = node;
}
static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
{
nst->st_sock_time = ktime_get();
}
static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
{
nst->st_send_time = ktime_get();
}
static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
{
nst->st_status_time = ktime_get();
}
static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
struct o2net_sock_container *sc)
{
nst->st_sc = sc;
}
static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
u32 msg_id)
{
nst->st_id = msg_id;
}
static inline void o2net_set_sock_timer(struct o2net_sock_container *sc)
{
sc->sc_tv_timer = ktime_get();
}
static inline void o2net_set_data_ready_time(struct o2net_sock_container *sc)
{
sc->sc_tv_data_ready = ktime_get();
}
static inline void o2net_set_advance_start_time(struct o2net_sock_container *sc)
{
sc->sc_tv_advance_start = ktime_get();
}
static inline void o2net_set_advance_stop_time(struct o2net_sock_container *sc)
{
sc->sc_tv_advance_stop = ktime_get();
}
static inline void o2net_set_func_start_time(struct o2net_sock_container *sc)
{
sc->sc_tv_func_start = ktime_get();
}
static inline void o2net_set_func_stop_time(struct o2net_sock_container *sc)
{
sc->sc_tv_func_stop = ktime_get();
}
#else /* CONFIG_DEBUG_FS */
# define o2net_init_nst(a, b, c, d, e)
# define o2net_set_nst_sock_time(a)
# define o2net_set_nst_send_time(a)
# define o2net_set_nst_status_time(a)
# define o2net_set_nst_sock_container(a, b)
# define o2net_set_nst_msg_id(a, b)
# define o2net_set_sock_timer(a)
# define o2net_set_data_ready_time(a)
# define o2net_set_advance_start_time(a)
# define o2net_set_advance_stop_time(a)
# define o2net_set_func_start_time(a)
# define o2net_set_func_stop_time(a)
#endif /* CONFIG_DEBUG_FS */
#ifdef CONFIG_OCFS2_FS_STATS
static ktime_t o2net_get_func_run_time(struct o2net_sock_container *sc)
{
return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start);
}
static void o2net_update_send_stats(struct o2net_send_tracking *nst,
struct o2net_sock_container *sc)
{
sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total,
ktime_sub(ktime_get(),
nst->st_status_time));
sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total,
ktime_sub(nst->st_status_time,
nst->st_send_time));
sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total,
ktime_sub(nst->st_send_time,
nst->st_sock_time));
sc->sc_send_count++;
}
static void o2net_update_recv_stats(struct o2net_sock_container *sc)
{
sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total,
o2net_get_func_run_time(sc));
sc->sc_recv_count++;
}
#else
# define o2net_update_send_stats(a, b)
# define o2net_update_recv_stats(sc)
#endif /* CONFIG_OCFS2_FS_STATS */
static inline unsigned int o2net_reconnect_delay(void)
{
return o2nm_single_cluster->cl_reconnect_delay_ms;
}
static inline unsigned int o2net_keepalive_delay(void)
{
return o2nm_single_cluster->cl_keepalive_delay_ms;
}
static inline unsigned int o2net_idle_timeout(void)
{
return o2nm_single_cluster->cl_idle_timeout_ms;
}
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;
spin_lock(&nn->nn_lock);
ret = idr_alloc(&nn->nn_status_idr, nsw, 0, 0, GFP_ATOMIC);
if (ret >= 0) {
nsw->ns_id = ret;
list_add_tail(&nsw->ns_node_item, &nn->nn_status_list);
}
spin_unlock(&nn->nn_lock);
if (ret < 0)
return ret;
init_waitqueue_head(&nsw->ns_wq);
nsw->ns_sys_status = O2NET_ERR_NONE;
nsw->ns_status = 0;
return 0;
}
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 o2net_status_wait *nsw, *tmp;
unsigned int num_kills = 0;
assert_spin_locked(&nn->nn_lock);
list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, 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);
BUG_ON(timer_pending(&sc->sc_idle_timeout));
sclog(sc, "releasing\n");
if (sc->sc_sock) {
sock_release(sc->sc_sock);
sc->sc_sock = NULL;
}
o2nm_undepend_item(&sc->sc_node->nd_item);
o2nm_node_put(sc->sc_node);
sc->sc_node = NULL;
o2net_debug_del_sc(sc);
if (sc->sc_page)
__free_page(sc->sc_page);
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;
int status = 0;
page = alloc_page(GFP_NOFS);
sc = kzalloc(sizeof(*sc), GFP_NOFS);
if (sc == NULL || page == NULL)
goto out;
kref_init(&sc->sc_kref);
o2nm_node_get(node);
sc->sc_node = node;
/* pin the node item of the remote node */
status = o2nm_depend_item(&node->nd_item);
if (status) {
mlog_errno(status);
o2nm_node_put(node);
goto out;
}
INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
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;
o2net_debug_add_sc(sc);
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 delayed_work *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 delayed_work *work)
{
if (cancel_delayed_work(work))
sc_put(sc);
}
static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
int o2net_num_connected_peers(void)
{
return atomic_read(&o2net_connected_peers);
}
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);
if (old_sc && !sc)
atomic_dec(&o2net_connected_peers);
else if (!old_sc && sc)
atomic_inc(&o2net_connected_peers);
/* 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);
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_valid && !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) {
if (old_sc)
printk(KERN_NOTICE "o2net: 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));
cancel_delayed_work(&nn->nn_connect_expired);
printk(KERN_NOTICE "o2net: %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 within a RECONNECT_DELAY of the
* last attempt */
delay = (nn->nn_last_connect_attempt +
msecs_to_jiffies(o2net_reconnect_delay()))
- jiffies;
if (delay > msecs_to_jiffies(o2net_reconnect_delay()))
delay = 0;
mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
/*
* Delay the expired work after idle timeout.
*
* We might have lots of failed connection attempts that run
* through here but we only cancel the connect_expired work when
* a connection attempt succeeds. So only the first enqueue of
* the connect_expired work will do anything. The rest will see
* that it's already queued and do nothing.
*/
delay += msecs_to_jiffies(o2net_idle_timeout());
queue_delayed_work(o2net_wq, &nn->nn_connect_expired, 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)
{
void (*ready)(struct sock *sk);
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");
o2net_set_data_ready_time(sc);
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);
}
/* 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:
printk(KERN_INFO "o2net: Connection to " SC_NODEF_FMT
" shutdown, state %d\n",
SC_NODEF_ARGS(sc), sk->sk_state);
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;
mutex_init(&sc->sc_send_lock);
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(struct work_struct *work)
{
struct o2net_sock_container *sc =
container_of(work, struct o2net_sock_container,
sc_shutdown_work);
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);
kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
}
/* 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,
o2net_post_msg_handler_func *post_func,
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 = kzalloc(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_post_func = post_func;
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* registered "
"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 o2net_msg_handler *nmh, *n;
write_lock(&o2net_handler_lock);
list_for_each_entry_safe(nmh, n, list, 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)
{
struct kvec vec = { .iov_len = len, .iov_base = data, };
struct msghdr msg = { .msg_flags = MSG_DONTWAIT, };
return kernel_recvmsg(sock, &msg, &vec, 1, len, msg.msg_flags);
}
static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
size_t veclen, size_t total)
{
int ret;
struct msghdr msg = {.msg_flags = 0,};
if (sock == NULL) {
ret = -EINVAL;
goto out;
}
ret = kernel_sendmsg(sock, &msg, vec, veclen, total);
if (likely(ret == total))
return 0;
mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret, total);
if (ret >= 0)
ret = -EPIPE; /* should be smarter, I bet */
out:
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;
while (1) {
mutex_lock(&sc->sc_send_lock);
ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
virt_to_page(kmalloced_virt),
(long)kmalloced_virt & ~PAGE_MASK,
size, MSG_DONTWAIT);
mutex_unlock(&sc->sc_send_lock);
if (ret == size)
break;
if (ret == (ssize_t)-EAGAIN) {
mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
" returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
cond_resched();
continue;
}
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);
break;
}
}
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;
}
/* Get a map of all nodes to which this node is currently connected to */
void o2net_fill_node_map(unsigned long *map, unsigned bytes)
{
struct o2net_sock_container *sc;
int node, ret;
BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
memset(map, 0, bytes);
for (node = 0; node < O2NM_MAX_NODES; ++node) {
if (!o2net_tx_can_proceed(o2net_nn_from_num(node), &sc, &ret))
continue;
if (!ret) {
set_bit(node, map);
sc_put(sc);
}
}
}
EXPORT_SYMBOL_GPL(o2net_fill_node_map);
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 = 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),
};
struct o2net_send_tracking nst;
o2net_init_nst(&nst, msg_type, key, current, target_node);
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;
}
o2net_debug_add_nst(&nst);
o2net_set_nst_sock_time(&nst);
wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret));
if (ret)
goto out;
o2net_set_nst_sock_container(&nst, sc);
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);
o2net_set_nst_msg_id(&nst, nsw.ns_id);
o2net_set_nst_send_time(&nst);
/* finally, convert the message header to network byte-order
* and send */
mutex_lock(&sc->sc_send_lock);
ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
sizeof(struct o2net_msg) + caller_bytes);
mutex_unlock(&sc->sc_send_lock);
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 */
o2net_set_nst_status_time(&nst);
wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
o2net_update_send_stats(&nst, sc);
/* 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:
o2net_debug_del_nst(&nst); /* must be before dropping sc and node */
if (sc)
sc_put(sc);
kfree(vec);
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;
void *ret_data = 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;
o2net_set_func_start_time(sc);
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, &ret_data);
o2net_set_func_stop_time(sc);
o2net_update_recv_stats(sc);
out_respond:
/* this destroys the hdr, so don't use it after this */
mutex_lock(&sc->sc_send_lock);
ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
handler_status);
mutex_unlock(&sc->sc_send_lock);
hdr = NULL;
mlog(0, "sending handler status %d, syserr %d returned %d\n",
handler_status, syserr, ret);
if (nmh) {
BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
if (nmh->nh_post_func)
(nmh->nh_post_func)(handler_status, nmh->nh_func_data,
ret_data);
}
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)) {
printk(KERN_NOTICE "o2net: " 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;
}
/*
* Ensure timeouts are consistent with other nodes, otherwise
* we can end up with one node thinking that the other must be down,
* but isn't. This can ultimately cause corruption.
*/
if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
o2net_idle_timeout()) {
printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a network "
"idle timeout of %u ms, but we use %u ms locally. "
"Disconnecting.\n", SC_NODEF_ARGS(sc),
be32_to_cpu(hand->o2net_idle_timeout_ms),
o2net_idle_timeout());
o2net_ensure_shutdown(nn, sc, -ENOTCONN);
return -1;
}
if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
o2net_keepalive_delay()) {
printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a keepalive "
"delay of %u ms, but we use %u ms locally. "
"Disconnecting.\n", SC_NODEF_ARGS(sc),
be32_to_cpu(hand->o2net_keepalive_delay_ms),
o2net_keepalive_delay());
o2net_ensure_shutdown(nn, sc, -ENOTCONN);
return -1;
}
if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
O2HB_MAX_WRITE_TIMEOUT_MS) {
printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a heartbeat "
"timeout of %u ms, but we use %u ms locally. "
"Disconnecting.\n", SC_NODEF_ARGS(sc),
be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
O2HB_MAX_WRITE_TIMEOUT_MS);
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_reset_idle_timer(sc);
atomic_set(&nn->nn_timeout, 0);
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");
o2net_set_advance_start_time(sc);
if (unlikely(sc->sc_handshake_ok == 0)) {
if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
data = page_address(sc->sc_page) + sc->sc_page_off;
datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
if (ret > 0)
sc->sc_page_off += ret;
}
if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
o2net_check_handshake(sc);
if (unlikely(sc->sc_handshake_ok == 0))
ret = -EPROTO;
}
goto out;
}
/* 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;
/* only swab incoming here.. we can
* only get here once as we cross from
* being under to over */
if (sc->sc_page_off == sizeof(struct o2net_msg)) {
hdr = page_address(sc->sc_page);
if (be16_to_cpu(hdr->data_len) >
O2NET_MAX_PAYLOAD_BYTES)
ret = -EOVERFLOW;
}
}
if (ret <= 0)
goto out;
}
if (sc->sc_page_off < sizeof(struct o2net_msg)) {
/* oof, still don't have a header */
goto out;
}
/* this was swabbed above when we first read it */
hdr = page_address(sc->sc_page);
msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
/* do we need more payload? */
if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
/* need more payload */
data = page_address(sc->sc_page) + sc->sc_page_off;
datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
sc->sc_page_off;
ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
if (ret > 0)
sc->sc_page_off += ret;
if (ret <= 0)
goto out;
}
if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
/* we can only get here once, the first time we read
* the payload.. so set ret to progress if the handler
* works out. after calling this the message is toast */
ret = o2net_process_message(sc, hdr);
if (ret == 0)
ret = 1;
sc->sc_page_off = 0;
}
out:
sclog(sc, "ret = %d\n", ret);
o2net_set_advance_stop_time(sc);
return ret;
}
/* this work func is triggerd by data ready. it reads until it can read no
* more. it interprets 0, eof, as fatal. if data_ready hits while we're doing
* our work the work struct will be marked and we'll be called again. */
static void o2net_rx_until_empty(struct work_struct *work)
{
struct o2net_sock_container *sc =
container_of(work, struct o2net_sock_container, sc_rx_work);
int ret;
do {
ret = o2net_advance_rx(sc);
} while (ret > 0);
if (ret <= 0 && ret != -EAGAIN) {
struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
sclog(sc, "saw error %d, closing\n", ret);
/* not permanent so read failed handshake can retry */
o2net_ensure_shutdown(nn, sc, 0);
}
sc_put(sc);
}
static int o2net_set_nodelay(struct socket *sock)
{
int ret, val = 1;
mm_segment_t oldfs;
oldfs = get_fs();
set_fs(KERNEL_DS);
/*
* Dear unsuspecting programmer,
*
* Don't use sock_setsockopt() for SOL_TCP. It doesn't check its level
* argument and assumes SOL_SOCKET so, say, your TCP_NODELAY will
* silently turn into SO_DEBUG.
*
* Yours,
* Keeper of hilariously fragile interfaces.
*/
ret = sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY,
(char __user *)&val, sizeof(val));
set_fs(oldfs);
return ret;
}
static int o2net_set_usertimeout(struct socket *sock)
{
int user_timeout = O2NET_TCP_USER_TIMEOUT;
return kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
(char *)&user_timeout, sizeof(user_timeout));
}
static void o2net_initialize_handshake(void)
{
o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
O2HB_MAX_WRITE_TIMEOUT_MS);
o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout());
o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
o2net_keepalive_delay());
o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
o2net_reconnect_delay());
}
/* ------------------------------------------------------------ */
/* called when a connect completes and after a sock is accepted. the
* rx path will see the response and mark the sc valid */
static void o2net_sc_connect_completed(struct work_struct *work)
{
struct o2net_sock_container *sc =
container_of(work, struct o2net_sock_container,
sc_connect_work);
mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
(unsigned long long)O2NET_PROTOCOL_VERSION,
(unsigned long long)be64_to_cpu(o2net_hand->connector_id));
o2net_initialize_handshake();
o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
sc_put(sc);
}
/* this is called as a work_struct func. */
static void o2net_sc_send_keep_req(struct work_struct *work)
{
struct o2net_sock_container *sc =
container_of(work, struct o2net_sock_container,
sc_keepalive_work.work);
o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
sc_put(sc);
}
/* socket shutdown does a del_timer_sync against this as it tears down.
* we can't start this timer until we've got to the point in sc buildup
* where shutdown is going to be involved */
static void o2net_idle_timer(unsigned long data)
{
struct o2net_sock_container *sc = (struct o2net_sock_container *)data;
struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
#ifdef CONFIG_DEBUG_FS
unsigned long msecs = ktime_to_ms(ktime_get()) -
ktime_to_ms(sc->sc_tv_timer);
#else
unsigned long msecs = o2net_idle_timeout();
#endif
printk(KERN_NOTICE "o2net: Connection to " SC_NODEF_FMT " has been "
"idle for %lu.%lu secs.\n",
SC_NODEF_ARGS(sc), msecs / 1000, msecs % 1000);
/* idle timerout happen, don't shutdown the connection, but
* make fence decision. Maybe the connection can recover before
* the decision is made.
*/
atomic_set(&nn->nn_timeout, 1);
o2quo_conn_err(o2net_num_from_nn(nn));
queue_delayed_work(o2net_wq, &nn->nn_still_up,
msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
o2net_sc_reset_idle_timer(sc);
}
static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
{
o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
msecs_to_jiffies(o2net_keepalive_delay()));
o2net_set_sock_timer(sc);
mod_timer(&sc->sc_idle_timeout,
jiffies + msecs_to_jiffies(o2net_idle_timeout()));
}
static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
{
struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
/* clear fence decision since the connection recover from timeout*/
if (atomic_read(&nn->nn_timeout)) {
o2quo_conn_up(o2net_num_from_nn(nn));
cancel_delayed_work(&nn->nn_still_up);
atomic_set(&nn->nn_timeout, 0);
}
/* Only push out an existing timer */
if (timer_pending(&sc->sc_idle_timeout))
o2net_sc_reset_idle_timer(sc);
}
/* this work func is kicked whenever a path sets the nn state which doesn't
* have valid set. This includes seeing hb come up, losing a connection,
* having a connect attempt fail, etc. This centralizes the logic which decides
* if a connect attempt should be made or if we should give up and all future
* transmit attempts should fail */
static void o2net_start_connect(struct work_struct *work)
{
struct o2net_node *nn =
container_of(work, struct o2net_node, nn_connect_work.work);
struct o2net_sock_container *sc = NULL;
struct o2nm_node *node = NULL, *mynode = NULL;
struct socket *sock = NULL;
struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
int ret = 0, stop;
unsigned int timeout;
unsigned int noio_flag;
/*
* sock_create allocates the sock with GFP_KERNEL. We must set
* per-process flag PF_MEMALLOC_NOIO so that all allocations done
* by this process are done as if GFP_NOIO was specified. So we
* are not reentering filesystem while doing memory reclaim.
*/
noio_flag = memalloc_noio_save();
/* if we're greater we initiate tx, otherwise we accept */
if (o2nm_this_node() <= o2net_num_from_nn(nn))
goto out;
/* watch for racing with tearing a node down */
node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
if (node == NULL) {
ret = 0;
goto out;
}
mynode = o2nm_get_node_by_num(o2nm_this_node());
if (mynode == NULL) {
ret = 0;
goto out;
}
spin_lock(&nn->nn_lock);
/*
* see if we already have one pending or have given up.
* For nn_timeout, it is set when we close the connection
* because of the idle time out. So it means that we have
* at least connected to that node successfully once,
* now try to connect to it again.
*/
timeout = atomic_read(&nn->nn_timeout);
stop = (nn->nn_sc ||
(nn->nn_persistent_error &&
(nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
spin_unlock(&nn->nn_lock);
if (stop)
goto out;
nn->nn_last_connect_attempt = jiffies;
sc = sc_alloc(node);
if (sc == NULL) {
mlog(0, "couldn't allocate sc\n");
ret = -ENOMEM;
goto out;
}
ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
if (ret < 0) {
mlog(0, "can't create socket: %d\n", ret);
goto out;
}
sc->sc_sock = sock; /* freed by sc_kref_release */
sock->sk->sk_allocation = GFP_ATOMIC;
myaddr.sin_family = AF_INET;
myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
myaddr.sin_port = htons(0); /* any port */
ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
sizeof(myaddr));
if (ret) {
mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
ret, &mynode->nd_ipv4_address);
goto out;
}
ret = o2net_set_nodelay(sc->sc_sock);
if (ret) {
mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
goto out;
}
ret = o2net_set_usertimeout(sock);
if (ret) {
mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret);
goto out;
}
o2net_register_callbacks(sc->sc_sock->sk, sc);
spin_lock(&nn->nn_lock);
/* handshake completion will set nn->nn_sc_valid */
o2net_set_nn_state(nn, sc, 0, 0);
spin_unlock(&nn->nn_lock);
remoteaddr.sin_family = AF_INET;
remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
remoteaddr.sin_port = node->nd_ipv4_port;
ret = sc->sc_sock->ops->connect(sc->sc_sock,
(struct sockaddr *)&remoteaddr,
sizeof(remoteaddr),
O_NONBLOCK);
if (ret == -EINPROGRESS)
ret = 0;
out:
if (ret && sc) {
printk(KERN_NOTICE "o2net: Connect attempt to " SC_NODEF_FMT
" failed with errno %d\n", SC_NODEF_ARGS(sc), ret);
/* 0 err so that another will be queued and attempted
* from set_nn_state */
o2net_ensure_shutdown(nn, sc, 0);
}
if (sc)
sc_put(sc);
if (node)
o2nm_node_put(node);
if (mynode)
o2nm_node_put(mynode);
memalloc_noio_restore(noio_flag);
return;
}
static void o2net_connect_expired(struct work_struct *work)
{
struct o2net_node *nn =
container_of(work, struct o2net_node, nn_connect_expired.work);
spin_lock(&nn->nn_lock);
if (!nn->nn_sc_valid) {
printk(KERN_NOTICE "o2net: No connection established with "
"node %u after %u.%u seconds, check network and"
" cluster configuration.\n",
o2net_num_from_nn(nn),
o2net_idle_timeout() / 1000,
o2net_idle_timeout() % 1000);
o2net_set_nn_state(nn, NULL, 0, 0);
}
spin_unlock(&nn->nn_lock);
}
static void o2net_still_up(struct work_struct *work)
{
struct o2net_node *nn =
container_of(work, struct o2net_node, nn_still_up.work);
o2quo_hb_still_up(o2net_num_from_nn(nn));
}
/* ------------------------------------------------------------ */
void o2net_disconnect_node(struct o2nm_node *node)
{
struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
/* don't reconnect until it's heartbeating again */
spin_lock(&nn->nn_lock);
atomic_set(&nn->nn_timeout, 0);
o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
spin_unlock(&nn->nn_lock);
if (o2net_wq) {
cancel_delayed_work(&nn->nn_connect_expired);
cancel_delayed_work(&nn->nn_connect_work);
cancel_delayed_work(&nn->nn_still_up);
flush_workqueue(o2net_wq);
}
}
static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
void *data)
{
o2quo_hb_down(node_num);
if (!node)
return;
if (node_num != o2nm_this_node())
o2net_disconnect_node(node);
BUG_ON(atomic_read(&o2net_connected_peers) < 0);
}
static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
void *data)
{
struct o2net_node *nn = o2net_nn_from_num(node_num);
o2quo_hb_up(node_num);
BUG_ON(!node);
/* ensure an immediate connect attempt */
nn->nn_last_connect_attempt = jiffies -
(msecs_to_jiffies(o2net_reconnect_delay()) + 1);
if (node_num != o2nm_this_node()) {
/* believe it or not, accept and node hearbeating testing
* can succeed for this node before we got here.. so
* only use set_nn_state to clear the persistent error
* if that hasn't already happened */
spin_lock(&nn->nn_lock);
atomic_set(&nn->nn_timeout, 0);
if (nn->nn_persistent_error)
o2net_set_nn_state(nn, NULL, 0, 0);
spin_unlock(&nn->nn_lock);
}
}
void o2net_unregister_hb_callbacks(void)
{
o2hb_unregister_callback(NULL, &o2net_hb_up);
o2hb_unregister_callback(NULL, &o2net_hb_down);
}
int o2net_register_hb_callbacks(void)
{
int ret;
o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
ret = o2hb_register_callback(NULL, &o2net_hb_up);
if (ret == 0)
ret = o2hb_register_callback(NULL, &o2net_hb_down);
if (ret)
o2net_unregister_hb_callbacks();
return ret;
}
/* ------------------------------------------------------------ */
static int o2net_accept_one(struct socket *sock, int *more)
{
int ret, slen;
struct sockaddr_in sin;
struct socket *new_sock = NULL;
struct o2nm_node *node = NULL;
struct o2nm_node *local_node = NULL;
struct o2net_sock_container *sc = NULL;
struct o2net_node *nn;
unsigned int noio_flag;
/*
* sock_create_lite allocates the sock with GFP_KERNEL. We must set
* per-process flag PF_MEMALLOC_NOIO so that all allocations done
* by this process are done as if GFP_NOIO was specified. So we
* are not reentering filesystem while doing memory reclaim.
*/
noio_flag = memalloc_noio_save();
BUG_ON(sock == NULL);
*more = 0;
ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
sock->sk->sk_protocol, &new_sock);
if (ret)
goto out;
new_sock->type = sock->type;
new_sock->ops = sock->ops;
ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
if (ret < 0)
goto out;
*more = 1;
new_sock->sk->sk_allocation = GFP_ATOMIC;
ret = o2net_set_nodelay(new_sock);
if (ret) {
mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
goto out;
}
ret = o2net_set_usertimeout(new_sock);
if (ret) {
mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret);
goto out;
}
slen = sizeof(sin);
ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin,
&slen, 1);
if (ret < 0)
goto out;
node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
if (node == NULL) {
printk(KERN_NOTICE "o2net: Attempt to connect from unknown "
"node at %pI4:%d\n", &sin.sin_addr.s_addr,
ntohs(sin.sin_port));
ret = -EINVAL;
goto out;
}
if (o2nm_this_node() >= node->nd_num) {
local_node = o2nm_get_node_by_num(o2nm_this_node());
if (local_node)
printk(KERN_NOTICE "o2net: Unexpected connect attempt "
"seen at node '%s' (%u, %pI4:%d) from "
"node '%s' (%u, %pI4:%d)\n",
local_node->nd_name, local_node->nd_num,
&(local_node->nd_ipv4_address),
ntohs(local_node->nd_ipv4_port),
node->nd_name,
node->nd_num, &sin.sin_addr.s_addr,
ntohs(sin.sin_port));
ret = -EINVAL;
goto out;
}
/* this happens all the time when the other node sees our heartbeat
* and tries to connect before we see their heartbeat */
if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
mlog(ML_CONN, "attempt to connect from node '%s' at "
"%pI4:%d but it isn't heartbeating\n",
node->nd_name, &sin.sin_addr.s_addr,
ntohs(sin.sin_port));
ret = -EINVAL;
goto out;
}
nn = o2net_nn_from_num(node->nd_num);
spin_lock(&nn->nn_lock);
if (nn->nn_sc)
ret = -EBUSY;
else
ret = 0;
spin_unlock(&nn->nn_lock);
if (ret) {
printk(KERN_NOTICE "o2net: Attempt to connect from node '%s' "
"at %pI4:%d but it already has an open connection\n",
node->nd_name, &sin.sin_addr.s_addr,
ntohs(sin.sin_port));
goto out;
}
sc = sc_alloc(node);
if (sc == NULL) {
ret = -ENOMEM;
goto out;
}
sc->sc_sock = new_sock;
new_sock = NULL;
spin_lock(&nn->nn_lock);
atomic_set(&nn->nn_timeout, 0);
o2net_set_nn_state(nn, sc, 0, 0);
spin_unlock(&nn->nn_lock);
o2net_register_callbacks(sc->sc_sock->sk, sc);
o2net_sc_queue_work(sc, &sc->sc_rx_work);
o2net_initialize_handshake();
o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
out:
if (new_sock)
sock_release(new_sock);
if (node)
o2nm_node_put(node);
if (local_node)
o2nm_node_put(local_node);
if (sc)
sc_put(sc);
memalloc_noio_restore(noio_flag);
return ret;
}
/*
* This function is invoked in response to one or more
* pending accepts at softIRQ level. We must drain the
* entire que before returning.
*/
static void o2net_accept_many(struct work_struct *work)
{
struct socket *sock = o2net_listen_sock;
int more;
int err;
/*
* It is critical to note that due to interrupt moderation
* at the network driver level, we can't assume to get a
* softIRQ for every single conn since tcp SYN packets
* can arrive back-to-back, and therefore many pending
* accepts may result in just 1 softIRQ. If we terminate
* the o2net_accept_one() loop upon seeing an err, what happens
* to the rest of the conns in the queue? If no new SYN
* arrives for hours, no softIRQ will be delivered,
* and the connections will just sit in the queue.
*/
for (;;) {
err = o2net_accept_one(sock, &more);
if (!more)
break;
cond_resched();
}
}
static void o2net_listen_data_ready(struct sock *sk)
{
void (*ready)(struct sock *sk);
read_lock(&sk->sk_callback_lock);
ready = sk->sk_user_data;
if (ready == NULL) { /* check for teardown race */
ready = sk->sk_data_ready;
goto out;
}
/* This callback may called twice when a new connection
* is being established as a child socket inherits everything
* from a parent LISTEN socket, including the data_ready cb of
* the parent. This leads to a hazard. In o2net_accept_one()
* we are still initializing the child socket but have not
* changed the inherited data_ready callback yet when
* data starts arriving.
* We avoid this hazard by checking the state.
* For the listening socket, the state will be TCP_LISTEN; for the new
* socket, will be TCP_ESTABLISHED. Also, in this case,
* sk->sk_user_data is not a valid function pointer.
*/
if (sk->sk_state == TCP_LISTEN) {
queue_work(o2net_wq, &o2net_listen_work);
} else {
ready = NULL;
}
out:
read_unlock(&sk->sk_callback_lock);
if (ready != NULL)
ready(sk);
}
static int o2net_open_listening_sock(__be32 addr, __be16 port)
{
struct socket *sock = NULL;
int ret;
struct sockaddr_in sin = {
.sin_family = PF_INET,
.sin_addr = { .s_addr = addr },
.sin_port = port,
};
ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
if (ret < 0) {
printk(KERN_ERR "o2net: Error %d while creating socket\n", ret);
goto out;
}
sock->sk->sk_allocation = GFP_ATOMIC;
write_lock_bh(&sock->sk->sk_callback_lock);
sock->sk->sk_user_data = sock->sk->sk_data_ready;
sock->sk->sk_data_ready = o2net_listen_data_ready;
write_unlock_bh(&sock->sk->sk_callback_lock);
o2net_listen_sock = sock;
INIT_WORK(&o2net_listen_work, o2net_accept_many);
sock->sk->sk_reuse = SK_CAN_REUSE;
ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
if (ret < 0) {
printk(KERN_ERR "o2net: Error %d while binding socket at "
"%pI4:%u\n", ret, &addr, ntohs(port));
goto out;
}
ret = sock->ops->listen(sock, 64);
if (ret < 0)
printk(KERN_ERR "o2net: Error %d while listening on %pI4:%u\n",
ret, &addr, ntohs(port));
out:
if (ret) {
o2net_listen_sock = NULL;
if (sock)
sock_release(sock);
}
return ret;
}
/*
* called from node manager when we should bring up our network listening
* socket. node manager handles all the serialization to only call this
* once and to match it with o2net_stop_listening(). note,
* o2nm_this_node() doesn't work yet as we're being called while it
* is being set up.
*/
int o2net_start_listening(struct o2nm_node *node)
{
int ret = 0;
BUG_ON(o2net_wq != NULL);
BUG_ON(o2net_listen_sock != NULL);
mlog(ML_KTHREAD, "starting o2net thread...\n");
o2net_wq = create_singlethread_workqueue("o2net");
if (o2net_wq == NULL) {
mlog(ML_ERROR, "unable to launch o2net thread\n");
return -ENOMEM; /* ? */
}
ret = o2net_open_listening_sock(node->nd_ipv4_address,
node->nd_ipv4_port);
if (ret) {
destroy_workqueue(o2net_wq);
o2net_wq = NULL;
} else
o2quo_conn_up(node->nd_num);
return ret;
}
/* again, o2nm_this_node() doesn't work here as we're involved in
* tearing it down */
void o2net_stop_listening(struct o2nm_node *node)
{
struct socket *sock = o2net_listen_sock;
size_t i;
BUG_ON(o2net_wq == NULL);
BUG_ON(o2net_listen_sock == NULL);
/* stop the listening socket from generating work */
write_lock_bh(&sock->sk->sk_callback_lock);
sock->sk->sk_data_ready = sock->sk->sk_user_data;
sock->sk->sk_user_data = NULL;
write_unlock_bh(&sock->sk->sk_callback_lock);
for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
struct o2nm_node *node = o2nm_get_node_by_num(i);
if (node) {
o2net_disconnect_node(node);
o2nm_node_put(node);
}
}
/* finish all work and tear down the work queue */
mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
destroy_workqueue(o2net_wq);
o2net_wq = NULL;
sock_release(o2net_listen_sock);
o2net_listen_sock = NULL;
o2quo_conn_err(node->nd_num);
}
/* ------------------------------------------------------------ */
int o2net_init(void)
{
unsigned long i;
o2quo_init();
if (o2net_debugfs_init())
goto out;
o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);
o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp)
goto out;
o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
o2net_hand->connector_id = cpu_to_be64(1);
o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
struct o2net_node *nn = o2net_nn_from_num(i);
atomic_set(&nn->nn_timeout, 0);
spin_lock_init(&nn->nn_lock);
INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
INIT_DELAYED_WORK(&nn->nn_connect_expired,
o2net_connect_expired);
INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
/* until we see hb from a node we'll return einval */
nn->nn_persistent_error = -ENOTCONN;
init_waitqueue_head(&nn->nn_sc_wq);
idr_init(&nn->nn_status_idr);
INIT_LIST_HEAD(&nn->nn_status_list);
}
return 0;
out:
kfree(o2net_hand);
kfree(o2net_keep_req);
kfree(o2net_keep_resp);
o2quo_exit();
return -ENOMEM;
}
void o2net_exit(void)
{
o2quo_exit();
kfree(o2net_hand);
kfree(o2net_keep_req);
kfree(o2net_keep_resp);
o2net_debugfs_exit();
}
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