mars/kernel/mars_server.c
2013-10-17 07:48:32 +02:00

864 lines
22 KiB
C

// (c) 2010 Thomas Schoebel-Theuer / 1&1 Internet AG
// Server brick (just for demonstration)
//#define BRICK_DEBUGGING
//#define MARS_DEBUGGING
//#define IO_DEBUGGING
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#define _STRATEGY
#include "mars.h"
#include "mars_bio.h"
#include "mars_aio.h"
#include "mars_sio.h"
///////////////////////// own type definitions ////////////////////////
#include "mars_server.h"
#define NR_SOCKETS 3
static struct mars_socket server_socket[NR_SOCKETS] = {};
static struct task_struct *server_thread[NR_SOCKETS] = {};
atomic_t server_handler_count = ATOMIC_INIT(0);
EXPORT_SYMBOL_GPL(server_handler_count);
///////////////////////// own helper functions ////////////////////////
static
int cb_thread(void *data)
{
struct server_brick *brick = data;
struct mars_socket *sock = &brick->handler_socket;
bool aborted = false;
bool ok = mars_get_socket(sock);
int status = -EINVAL;
MARS_DBG("--------------- cb_thread starting on socket #%d, ok = %d\n", sock->s_debug_nr, ok);
if (!ok)
goto done;
brick->cb_running = true;
wake_up_interruptible(&brick->startup_event);
while (!brick_thread_should_stop() || !list_empty(&brick->cb_read_list) || !list_empty(&brick->cb_write_list) || atomic_read(&brick->in_flight) > 0) {
struct server_mref_aspect *mref_a;
struct mref_object *mref;
struct list_head *tmp;
unsigned long flags;
wait_event_interruptible_timeout(
brick->cb_event,
!list_empty(&brick->cb_read_list) ||
!list_empty(&brick->cb_write_list),
1 * HZ);
traced_lock(&brick->cb_lock, flags);
tmp = brick->cb_write_list.next;
if (tmp == &brick->cb_write_list) {
tmp = brick->cb_read_list.next;
if (tmp == &brick->cb_read_list) {
traced_unlock(&brick->cb_lock, flags);
brick_msleep(1000 / HZ);
continue;
}
}
list_del_init(tmp);
traced_unlock(&brick->cb_lock, flags);
mref_a = container_of(tmp, struct server_mref_aspect, cb_head);
mref = mref_a->object;
status = -EINVAL;
CHECK_PTR(mref, err);
status = 0;
if (!aborted) {
down(&brick->socket_sem);
status = mars_send_cb(sock, mref);
up(&brick->socket_sem);
}
err:
if (unlikely(status < 0) && !aborted) {
aborted = true;
MARS_WRN("cannot send response, status = %d\n", status);
/* Just shutdown the socket and forget all pending
* requests.
* The _client_ is responsible for resending
* any lost operations.
*/
mars_shutdown_socket(sock);
}
GENERIC_INPUT_CALL(brick->inputs[0], mref_put, mref);
atomic_dec(&brick->in_flight);
}
mars_shutdown_socket(sock);
mars_put_socket(sock);
done:
MARS_DBG("---------- cb_thread terminating, status = %d\n", status);
wake_up_interruptible(&brick->startup_event);
return status;
}
static
void server_endio(struct generic_callback *cb)
{
struct server_mref_aspect *mref_a;
struct mref_object *mref;
struct server_brick *brick;
int rw;
unsigned long flags;
mref_a = cb->cb_private;
CHECK_PTR(mref_a, err);
mref = mref_a->object;
CHECK_PTR(mref, err);
brick = mref_a->brick;
if (!brick) {
MARS_WRN("late IO callback -- cannot do anything\n");
return;
}
rw = mref->ref_rw;
traced_lock(&brick->cb_lock, flags);
if (rw) {
list_add_tail(&mref_a->cb_head, &brick->cb_write_list);
} else {
list_add_tail(&mref_a->cb_head, &brick->cb_read_list);
}
traced_unlock(&brick->cb_lock, flags);
wake_up_interruptible(&brick->cb_event);
return;
err:
MARS_FAT("cannot handle callback - giving up\n");
}
int server_io(struct server_brick *brick, struct mars_socket *sock, struct mars_cmd *cmd)
{
struct mref_object *mref;
struct server_mref_aspect *mref_a;
int amount;
int status = -ENOTRECOVERABLE;
if (!brick->cb_running || !brick->handler_running || !mars_socket_is_alive(sock))
goto done;
mref = server_alloc_mref(brick);
status = -ENOMEM;
if (!mref)
goto done;
mref_a = server_mref_get_aspect(brick, mref);
if (unlikely(!mref_a)) {
mars_free_mref(mref);
goto done;
}
status = mars_recv_mref(sock, mref, cmd);
if (status < 0) {
mars_free_mref(mref);
goto done;
}
mref_a->brick = brick;
SETUP_CALLBACK(mref, server_endio, mref_a);
amount = 0;
if (!mref->ref_cs_mode < 2)
amount = (mref->ref_len - 1) / 1024 + 1;
mars_limit_sleep(&server_limiter, amount);
status = GENERIC_INPUT_CALL(brick->inputs[0], mref_get, mref);
if (unlikely(status < 0)) {
MARS_WRN("mref_get execution error = %d\n", status);
SIMPLE_CALLBACK(mref, status);
status = 0; // continue serving requests
goto done;
}
atomic_inc(&brick->in_flight);
GENERIC_INPUT_CALL(brick->inputs[0], mref_io, mref);
done:
return status;
}
static
void _clean_list(struct server_brick *brick, struct list_head *start)
{
for (;;) {
struct server_mref_aspect *mref_a;
struct mref_object *mref;
struct list_head *tmp = start->next;
if (tmp == start)
break;
list_del_init(tmp);
mref_a = container_of(tmp, struct server_mref_aspect, cb_head);
mref_a->brick = NULL;
mref = mref_a->object;
if (!mref)
continue;
GENERIC_INPUT_CALL(brick->inputs[0], mref_put, mref);
}
}
static
int _set_server_sio_params(struct mars_brick *_brick, void *private)
{
struct sio_brick *sio_brick = (void*)_brick;
if (_brick->type != (void*)_sio_brick_type) {
MARS_ERR("bad brick type\n");
return -EINVAL;
}
sio_brick->o_direct = false;
sio_brick->o_fdsync = false;
MARS_INF("name = '%s' path = '%s'\n", _brick->brick_name, _brick->brick_path);
return 1;
}
static
int _set_server_aio_params(struct mars_brick *_brick, void *private)
{
struct aio_brick *aio_brick = (void*)_brick;
if (_brick->type == (void*)_sio_brick_type) {
return _set_server_sio_params(_brick, private);
}
if (_brick->type != (void*)_aio_brick_type) {
MARS_ERR("bad brick type\n");
return -EINVAL;
}
aio_brick->o_creat = false;
aio_brick->o_direct = false;
aio_brick->o_fdsync = false;
MARS_INF("name = '%s' path = '%s'\n", _brick->brick_name, _brick->brick_path);
return 1;
}
static
int _set_server_bio_params(struct mars_brick *_brick, void *private)
{
struct bio_brick *bio_brick;
if (_brick->type == (void*)_aio_brick_type) {
return _set_server_aio_params(_brick, private);
}
if (_brick->type == (void*)_sio_brick_type) {
return _set_server_sio_params(_brick, private);
}
if (_brick->type != (void*)_bio_brick_type) {
MARS_ERR("bad brick type\n");
return -EINVAL;
}
bio_brick = (void*)_brick;
bio_brick->ra_pages = 0;
bio_brick->do_noidle = true;
bio_brick->do_sync = true;
bio_brick->do_unplug = true;
MARS_INF("name = '%s' path = '%s'\n", _brick->brick_name, _brick->brick_path);
return 1;
}
static
int dummy_worker(struct mars_global *global, struct mars_dent *dent, bool prepare, bool direction)
{
return 0;
}
static
int handler_thread(void *data)
{
struct server_brick *brick = data;
struct mars_socket *sock = &brick->handler_socket;
bool ok = mars_get_socket(sock);
int debug_nr;
int status = -EINVAL;
MARS_DBG("#%d --------------- handler_thread starting on socket %p\n", sock->s_debug_nr, sock);
if (!ok)
goto done;
brick->handler_running = true;
wake_up_interruptible(&brick->startup_event);
while (!brick_thread_should_stop() && mars_socket_is_alive(sock)) {
struct mars_cmd cmd = {};
status = -EINTR;
if (unlikely(!mars_global || !mars_global->global_power.button)) {
MARS_DBG("system is not alive\n");
break;
}
status = mars_recv_struct(sock, &cmd, mars_cmd_meta);
if (unlikely(status < 0)) {
MARS_WRN("#%d recv cmd status = %d\n", sock->s_debug_nr, status);
goto clean;
}
if (unlikely(!mars_socket_is_alive(sock))) {
MARS_WRN("#%d is dead\n", sock->s_debug_nr);
status = -EINTR;
goto clean;
}
MARS_IO("#%d cmd = %d\n", sock->s_debug_nr, cmd.cmd_code);
status = -EPROTO;
switch (cmd.cmd_code & CMD_FLAG_MASK) {
case CMD_NOP:
status = 0;
MARS_DBG("#%d got NOP operation\n", sock->s_debug_nr);
break;
case CMD_NOTIFY:
status = 0;
from_remote_trigger();
break;
case CMD_GETINFO:
{
struct mars_info info = {};
status = GENERIC_INPUT_CALL(brick->inputs[0], mars_get_info, &info);
if (status < 0) {
break;
}
down(&brick->socket_sem);
status = mars_send_struct(sock, &cmd, mars_cmd_meta);
if (status >= 0) {
status = mars_send_struct(sock, &info, mars_info_meta);
}
up(&brick->socket_sem);
break;
}
case CMD_GETENTS:
{
struct mars_global local = {
.dent_anchor = LIST_HEAD_INIT(local.dent_anchor),
.brick_anchor = LIST_HEAD_INIT(local.brick_anchor),
.global_power = {
.button = true,
},
.main_event = __WAIT_QUEUE_HEAD_INITIALIZER(local.main_event),
};
status = -EINVAL;
if (unlikely(!cmd.cmd_str1))
break;
init_rwsem(&local.dent_mutex);
init_rwsem(&local.brick_mutex);
status = mars_dent_work(&local, "/mars", sizeof(struct mars_dent), light_checker, dummy_worker, &local, 3);
down(&brick->socket_sem);
status = mars_send_dent_list(sock, &local.dent_anchor);
up(&brick->socket_sem);
if (status < 0) {
MARS_WRN("#%d could not send dentry information, status = %d\n", sock->s_debug_nr, status);
}
mars_free_dent_all(&local, &local.dent_anchor);
break;
}
case CMD_CONNECT:
{
struct mars_brick *prev;
const char *path = cmd.cmd_str1;
status = -EINVAL;
CHECK_PTR(path, err);
CHECK_PTR_NULL(_bio_brick_type, err);
if (!brick->global || !mars_global || !mars_global->global_power.button) {
MARS_WRN("#%d system is not alive\n", sock->s_debug_nr);
goto err;
}
prev = make_brick_all(
brick->global,
NULL,
_set_server_bio_params,
NULL,
path,
(const struct generic_brick_type*)_bio_brick_type,
(const struct generic_brick_type*[]){},
2, // start always
path,
(const char *[]){},
0);
if (likely(prev)) {
status = generic_connect((void*)brick->inputs[0], (void*)prev->outputs[0]);
if (unlikely(status < 0)) {
MARS_ERR("#%d cannot connect to '%s'\n", sock->s_debug_nr, path);
}
prev->killme = true;
} else {
MARS_ERR("#%d cannot find brick '%s'\n", sock->s_debug_nr, path);
}
err:
cmd.cmd_int1 = status;
down(&brick->socket_sem);
status = mars_send_struct(sock, &cmd, mars_cmd_meta);
up(&brick->socket_sem);
break;
}
case CMD_MREF:
{
#ifdef CONFIG_MARS_LOADAVG_LIMIT // quirk
int my_load = (avenrun[0] + FIXED_1/200) >> FSHIFT;
if (mars_max_loadavg && my_load >= mars_max_loadavg) {
MARS_WRN("#%d loadavg %d too high (%d), aborting data traffic\n", sock->s_debug_nr, my_load, mars_max_loadavg);
status = -EBUSY;
break;
}
#endif
status = server_io(brick, sock, &cmd);
break;
}
case CMD_CB:
MARS_ERR("#%d oops, as a server I should never get CMD_CB; something is wrong here - attack attempt??\n", sock->s_debug_nr);
break;
default:
MARS_ERR("#%d unknown command %d\n", sock->s_debug_nr, cmd.cmd_code);
}
clean:
brick_string_free(cmd.cmd_str1);
if (status < 0)
break;
}
mars_shutdown_socket(sock);
mars_put_socket(sock);
done:
MARS_DBG("#%d handler_thread terminating, status = %d\n", sock->s_debug_nr, status);
debug_nr = sock->s_debug_nr;
MARS_DBG("#%d done.\n", debug_nr);
atomic_dec(&server_handler_count);
brick->killme = true;
return status;
}
////////////////// own brick / input / output operations //////////////////
static int server_get_info(struct server_output *output, struct mars_info *info)
{
struct server_input *input = output->brick->inputs[0];
return GENERIC_INPUT_CALL(input, mars_get_info, info);
}
static int server_ref_get(struct server_output *output, struct mref_object *mref)
{
struct server_input *input = output->brick->inputs[0];
return GENERIC_INPUT_CALL(input, mref_get, mref);
}
static void server_ref_put(struct server_output *output, struct mref_object *mref)
{
struct server_input *input = output->brick->inputs[0];
GENERIC_INPUT_CALL(input, mref_put, mref);
}
static void server_ref_io(struct server_output *output, struct mref_object *mref)
{
struct server_input *input = output->brick->inputs[0];
GENERIC_INPUT_CALL(input, mref_io, mref);
}
static int server_switch(struct server_brick *brick)
{
struct mars_socket *sock = &brick->handler_socket;
int status = 0;
if (brick->power.button) {
static int version = 0;
bool ok;
if (brick->power.led_on)
goto done;
ok = mars_get_socket(sock);
if (unlikely(!ok)) {
status = -ENOENT;
goto err;
}
mars_power_led_off((void*)brick, false);
brick->cb_thread = brick_thread_create(cb_thread, brick, "mars_cb%d", version);
if (unlikely(!brick->cb_thread)) {
MARS_ERR("cannot create cb thread\n");
status = -ENOENT;
goto err;
}
brick->handler_thread = brick_thread_create(handler_thread, brick, "mars_handler%d", version++);
if (unlikely(!brick->handler_thread)) {
MARS_ERR("cannot create handler thread\n");
brick_thread_stop(brick->cb_thread);
brick->cb_thread = NULL;
status = -ENOENT;
goto err;
}
mars_power_led_on((void*)brick, true);
} else if (!brick->power.led_off) {
struct task_struct *thread;
mars_power_led_on((void*)brick, false);
mars_shutdown_socket(sock);
thread = brick->handler_thread;
if (thread) {
brick->handler_thread = NULL;
brick->handler_running = false;
MARS_DBG("#%d stopping handler thread....\n", sock->s_debug_nr);
brick_thread_stop(thread);
}
thread = brick->cb_thread;
if (thread) {
brick->cb_thread = NULL;
brick->cb_running = false;
MARS_DBG("#%d stopping callback thread....\n", sock->s_debug_nr);
brick_thread_stop(thread);
}
mars_put_socket(sock);
MARS_DBG("#%d socket s_count = %d\n", sock->s_debug_nr, atomic_read(&sock->s_count));
// do this only after _both_ threads have stopped...
_clean_list(brick, &brick->cb_read_list);
_clean_list(brick, &brick->cb_write_list);
mars_power_led_off((void*)brick, true);
}
err:
if (unlikely(status < 0)) {
mars_power_led_off((void*)brick, true);
mars_shutdown_socket(sock);
mars_put_socket(sock);
}
done:
return status;
}
//////////////// informational / statistics ///////////////
static
char *server_statistics(struct server_brick *brick, int verbose)
{
char *res = brick_string_alloc(1024);
if (!res)
return NULL;
snprintf(res, 1024,
"cb_running = %d "
"handler_running = %d "
"in_flight = %d\n",
brick->cb_running,
brick->handler_running,
atomic_read(&brick->in_flight));
return res;
}
static
void server_reset_statistics(struct server_brick *brick)
{
}
//////////////// object / aspect constructors / destructors ///////////////
static int server_mref_aspect_init_fn(struct generic_aspect *_ini)
{
struct server_mref_aspect *ini = (void*)_ini;
INIT_LIST_HEAD(&ini->cb_head);
return 0;
}
static void server_mref_aspect_exit_fn(struct generic_aspect *_ini)
{
struct server_mref_aspect *ini = (void*)_ini;
CHECK_HEAD_EMPTY(&ini->cb_head);
}
MARS_MAKE_STATICS(server);
////////////////////// brick constructors / destructors ////////////////////
static int server_brick_construct(struct server_brick *brick)
{
init_waitqueue_head(&brick->startup_event);
init_waitqueue_head(&brick->cb_event);
sema_init(&brick->socket_sem, 1);
spin_lock_init(&brick->cb_lock);
INIT_LIST_HEAD(&brick->cb_read_list);
INIT_LIST_HEAD(&brick->cb_write_list);
return 0;
}
static int server_brick_destruct(struct server_brick *brick)
{
CHECK_HEAD_EMPTY(&brick->cb_read_list);
CHECK_HEAD_EMPTY(&brick->cb_write_list);
return 0;
}
static int server_output_construct(struct server_output *output)
{
return 0;
}
///////////////////////// static structs ////////////////////////
static struct server_brick_ops server_brick_ops = {
.brick_switch = server_switch,
.brick_statistics = server_statistics,
.reset_statistics = server_reset_statistics,
};
static struct server_output_ops server_output_ops = {
.mars_get_info = server_get_info,
.mref_get = server_ref_get,
.mref_put = server_ref_put,
.mref_io = server_ref_io,
};
const struct server_input_type server_input_type = {
.type_name = "server_input",
.input_size = sizeof(struct server_input),
};
static const struct server_input_type *server_input_types[] = {
&server_input_type,
};
const struct server_output_type server_output_type = {
.type_name = "server_output",
.output_size = sizeof(struct server_output),
.master_ops = &server_output_ops,
.output_construct = &server_output_construct,
};
static const struct server_output_type *server_output_types[] = {
&server_output_type,
};
const struct server_brick_type server_brick_type = {
.type_name = "server_brick",
.brick_size = sizeof(struct server_brick),
.max_inputs = 1,
.max_outputs = 0,
.master_ops = &server_brick_ops,
.aspect_types = server_aspect_types,
.default_input_types = server_input_types,
.default_output_types = server_output_types,
.brick_construct = &server_brick_construct,
.brick_destruct = &server_brick_destruct,
};
EXPORT_SYMBOL_GPL(server_brick_type);
///////////////////////////////////////////////////////////////////////
// strategy layer
int server_show_statist = 0;
EXPORT_SYMBOL_GPL(server_show_statist);
static int _server_thread(void *data)
{
struct mars_global server_global = {
.dent_anchor = LIST_HEAD_INIT(server_global.dent_anchor),
.brick_anchor = LIST_HEAD_INIT(server_global.brick_anchor),
.global_power = {
.button = true,
},
.main_event = __WAIT_QUEUE_HEAD_INITIALIZER(server_global.main_event),
};
struct mars_socket *my_socket = data;
char *id = my_id();
int status = 0;
init_rwsem(&server_global.dent_mutex);
init_rwsem(&server_global.brick_mutex);
MARS_INF("-------- server starting on host '%s' ----------\n", id);
while (!brick_thread_should_stop() &&
(!mars_global || !mars_global->global_power.button)) {
MARS_DBG("system did not start up\n");
brick_msleep(5000);
}
MARS_INF("-------- server now working on host '%s' ----------\n", id);
while (!brick_thread_should_stop() || !list_empty(&server_global.brick_anchor)) {
struct server_brick *brick = NULL;
struct mars_socket handler_socket = {};
server_global.global_version++;
if (server_show_statist)
show_statistics(&server_global, "server");
status = mars_kill_brick_when_possible(&server_global, &server_global.brick_anchor, false, NULL, true);
MARS_DBG("kill server bricks (when possible) = %d\n", status);
if (!mars_global || !mars_global->global_power.button) {
brick_msleep(1000);
continue;
}
status = mars_accept_socket(&handler_socket, my_socket);
if (unlikely(status < 0 || !mars_socket_is_alive(&handler_socket))) {
brick_msleep(500);
if (status == -EAGAIN)
continue; // without error message
MARS_WRN("accept status = %d\n", status);
brick_msleep(1000);
continue;
}
handler_socket.s_shutdown_on_err = true;
MARS_DBG("got new connection #%d\n", handler_socket.s_debug_nr);
brick = (void*)mars_make_brick(&server_global, NULL, &server_brick_type, "handler", "handler");
if (!brick) {
MARS_ERR("cannot create server instance\n");
mars_shutdown_socket(&handler_socket);
mars_put_socket(&handler_socket);
brick_msleep(2000);
continue;
}
memcpy(&brick->handler_socket, &handler_socket, sizeof(struct mars_socket));
atomic_inc(&server_handler_count);
/* TODO: check authorization.
*/
brick->power.button = true;
status = server_switch(brick);
if (unlikely(status < 0)) {
MARS_ERR("cannot switch on server brick, status = %d\n", status);
goto err;
}
// further references are usually held by the threads
mars_put_socket(&brick->handler_socket);
/* fire and forget....
* the new instance is now responsible for itself.
*/
brick = NULL;
brick_msleep(100);
continue;
err:
if (brick) {
mars_shutdown_socket(&brick->handler_socket);
mars_put_socket(&brick->handler_socket);
status = mars_kill_brick((void*)brick);
if (status < 0) {
BRICK_ERR("kill status = %d, giving up\n", status);
}
brick = NULL;
atomic_dec(&server_handler_count);
}
brick_msleep(2000);
}
MARS_INF("-------- cleaning up ----------\n");
mars_kill_brick_all(&server_global, &server_global.brick_anchor, false);
//cleanup_mm();
MARS_INF("-------- done status = %d ----------\n", status);
return status;
}
////////////////// module init stuff /////////////////////////
struct mars_limiter server_limiter = {
.lim_max_rate = 0,
};
EXPORT_SYMBOL_GPL(server_limiter);
void __exit exit_mars_server(void)
{
int i;
MARS_INF("exit_server()\n");
server_unregister_brick_type();
for (i = 0; i < NR_SOCKETS; i++) {
if (server_thread[i]) {
MARS_INF("stopping server thread %d...\n", i);
brick_thread_stop(server_thread[i]);
}
MARS_INF("closing server socket %d...\n", i);
mars_put_socket(&server_socket[i]);
}
}
int __init init_mars_server(void)
{
int i;
MARS_INF("init_server()\n");
for (i = 0; i < NR_SOCKETS; i++) {
struct sockaddr_storage sockaddr = {};
char tmp[16];
int status;
sprintf(tmp, ":%d", mars_net_default_port + i);
status = mars_create_sockaddr(&sockaddr, tmp);
if (unlikely(status < 0)) {
exit_mars_server();
return status;
}
status = mars_create_socket(&server_socket[i], &sockaddr, true);
if (unlikely(status < 0)) {
MARS_ERR("could not create server socket %d, status = %d\n", i, status);
exit_mars_server();
return status;
}
server_thread[i] = brick_thread_create(_server_thread, &server_socket[i], "mars_server_%d", i);
if (unlikely(!server_thread[i] || IS_ERR(server_thread[i]))) {
MARS_ERR("could not create server thread %d\n", i);
exit_mars_server();
return -ENOENT;
}
}
return server_register_brick_type();
}
#ifndef CONFIG_MARS_HAVE_BIGMODULE
MODULE_DESCRIPTION("MARS server brick");
MODULE_AUTHOR("Thomas Schoebel-Theuer <tst@1und1.de>");
MODULE_LICENSE("GPL");
module_init(init_mars_server);
module_exit(exit_mars_server);
#endif