mars/kernel/mars_check.c
2014-11-25 18:09:17 +01:00

370 lines
9.3 KiB
C

/*
* MARS Long Distance Replication Software
*
* This file is part of MARS project: http://schoebel.github.io/mars/
*
* Copyright (C) 2010-2014 Thomas Schoebel-Theuer
* Copyright (C) 2011-2014 1&1 Internet AG
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* Check brick
* checks various semantic properties, uses watchdog to find lost callbacks.
*/
/* FIXME: this code has been unused for a long time, it is unlikly
* to work at all.
*/
/* FIXME: improve this a lot!
* Check really _anything_ in the interface which _could_ go wrong,
* even by the silliest type of accident!
*/
//#define BRICK_DEBUGGING
//#define MARS_DEBUGGING
//#define IO_DEBUGGING
//#define STAT_DEBUGGING
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include "mars.h"
///////////////////////// own type definitions ////////////////////////
#include "mars_check.h"
///////////////////////// own helper functions ////////////////////////
#define CHECK_ERR(output,fmt,args...) \
do { \
struct check_input *input = (output)->brick->inputs[0]; \
struct generic_output *other = (void*)input->connect; \
if (other) { \
MARS_ERR("instance %d/%s/%s: " fmt, \
(output)->instance_nr, \
other->type->type_name, \
other->output_name, \
##args); \
} else { \
MARS_ERR("instance %d: " fmt, \
(output)->instance_nr, \
##args); \
} \
} while (0)
static void check_endio(struct generic_callback *cb)
{
struct check_mref_aspect *mref_a;
struct mref_object *mref;
struct check_output *output;
struct check_input *input;
unsigned long flags;
mref_a = cb->cb_private;
CHECK_PTR(mref_a, fatal);
_CHECK(&mref_a->cb == cb, fatal);
mref = mref_a->object;
CHECK_PTR(mref, fatal);
output = mref_a->output;
CHECK_PTR(output, fatal);
input = output->brick->inputs[0];
CHECK_PTR(input, fatal);
if (atomic_dec_and_test(&mref_a->callback_count)) {
atomic_set(&mref_a->callback_count, 1);
CHECK_ERR(output, "too many callbacks on %p\n", mref);
}
#ifdef CHECK_LOCK
traced_lock(&output->check_lock, flags);
if (list_empty(&mref_a->mref_head)) {
CHECK_ERR(output, "list entry missing on %p\n", mref);
}
list_del_init(&mref_a->mref_head);
traced_unlock(&output->check_lock, flags);
#else
(void)flags;
#endif
mref_a->last_jiffies = jiffies;
NEXT_CHECKED_CALLBACK(cb, fatal);
return;
fatal:
brick_msleep(60000);
return;
}
#ifdef CHECK_LOCK
static void dump_mem(void *data, int len)
{
int i;
char *tmp;
char *buf = brick_string_alloc(0);
if (!buf)
return;
for (i = 0, tmp = buf; i < len; i++) {
unsigned char byte = ((unsigned char*)data)[i];
if (!(i % 8)) {
if (tmp != buf) {
say(-1, "%4d: %s\n", i, buf);
}
tmp = buf;
}
tmp += scnprintf(tmp, 1024 - i * 3, " %02x", byte);
}
if (tmp != buf) {
say(-1, "%4d: %s\n", i, buf);
}
brick_string_free(buf);
}
static int check_watchdog(void *data)
{
struct check_output *output = data;
MARS_INF("watchdog has started.\n");
while (!brick_thread_should_stop()) {
struct list_head *h;
unsigned long flags;
unsigned long now;
brick_msleep(5000);
traced_lock(&output->check_lock, flags);
now = jiffies;
for (h = output->mref_anchor.next; h != &output->mref_anchor; h = h->next) {
static int limit = 1;
const int timeout = 30;
struct check_mref_aspect *mref_a;
struct mref_object *mref;
unsigned long elapsed;
mref_a = container_of(h, struct check_mref_aspect, mref_head);
mref = mref_a->object;
elapsed = now - mref_a->last_jiffies;
if (elapsed > timeout * HZ && limit-- > 0) {
struct generic_object_layout *object_layout;
mref_a->last_jiffies = now + 600 * HZ;
MARS_INF("================================\n");
CHECK_ERR(output, "mref %p callback is missing for more than %d seconds.\n", mref, timeout);
object_layout = mref->object_layout;
dump_mem(mref, object_layout->size_hint);
MARS_INF("================================\n");
}
}
traced_unlock(&output->check_lock, flags);
}
return 0;
}
#endif
////////////////// own brick / input / output operations //////////////////
static int check_get_info(struct check_output *output, struct mars_info *info)
{
struct check_input *input = output->brick->inputs[0];
return GENERIC_INPUT_CALL(input, mars_get_info, info);
}
static int check_ref_get(struct check_output *output, struct mref_object *mref)
{
struct check_input *input = output->brick->inputs[0];
return GENERIC_INPUT_CALL(input, mref_get, mref);
}
static void check_ref_put(struct check_output *output, struct mref_object *mref)
{
struct check_input *input = output->brick->inputs[0];
GENERIC_INPUT_CALL(input, mref_put, mref);
}
static void check_ref_io(struct check_output *output, struct mref_object *mref)
{
struct check_input *input = output->brick->inputs[0];
struct check_mref_aspect *mref_a = check_mref_get_aspect(output->brick, mref);
unsigned long flags;
CHECK_PTR(mref_a, fatal);
if (atomic_dec_and_test(&mref_a->call_count)) {
atomic_set(&mref_a->call_count, 1);
CHECK_ERR(output, "multiple parallel calls on %p\n", mref);
}
atomic_set(&mref_a->callback_count, 2);
#ifdef CHECK_LOCK
traced_lock(&output->check_lock, flags);
if (!list_empty(&mref_a->mref_head)) {
CHECK_ERR(output, "list head not empty on %p\n", mref);
list_del(&mref_a->mref_head);
}
list_add_tail(&mref_a->mref_head, &output->mref_anchor);
traced_unlock(&output->check_lock, flags);
#else
(void)flags;
#endif
mref_a->last_jiffies = jiffies;
if (!mref_a->installed) {
mref_a->installed = true;
mref_a->output = output;
INSERT_CALLBACK(mref, &mref_a->cb, check_endio, mref_a);
}
GENERIC_INPUT_CALL(input, mref_io, mref);
atomic_inc(&mref_a->call_count);
fatal: ;
}
//////////////// object / aspect constructors / destructors ///////////////
static int check_mref_aspect_init_fn(struct generic_aspect *_ini)
{
struct check_mref_aspect *ini = (void*)_ini;
#ifdef CHECK_LOCK
INIT_LIST_HEAD(&ini->mref_head);
#endif
ini->last_jiffies = jiffies;
atomic_set(&ini->call_count, 2);
atomic_set(&ini->callback_count, 1);
ini->installed = false;
return 0;
}
static void check_mref_aspect_exit_fn(struct generic_aspect *_ini)
{
struct check_mref_aspect *ini = (void*)_ini;
(void)ini;
#ifdef CHECK_LOCK
if (!list_empty(&ini->mref_head)) {
struct check_output *output = ini->output;
if (output) {
CHECK_ERR(output, "list head not empty on %p\n", ini->object);
INIT_LIST_HEAD(&ini->mref_head);
} else {
CHECK_HEAD_EMPTY(&ini->mref_head);
}
}
#endif
}
MARS_MAKE_STATICS(check);
////////////////////// brick constructors / destructors ////////////////////
static int check_brick_construct(struct check_brick *brick)
{
return 0;
}
static int check_output_construct(struct check_output *output)
{
static int count = 0;
#ifdef CHECK_LOCK
spin_lock_init(&output->check_lock);
INIT_LIST_HEAD(&output->mref_anchor);
output->watchdog = brick_thread_create(check_watchdog, output, "check_watchdog%d", output->instance_nr);
#endif
output->instance_nr = ++count;
return 0;
}
///////////////////////// static structs ////////////////////////
static struct check_brick_ops check_brick_ops = {
};
static struct check_output_ops check_output_ops = {
.mars_get_info = check_get_info,
.mref_get = check_ref_get,
.mref_put = check_ref_put,
.mref_io = check_ref_io,
};
const struct check_input_type check_input_type = {
.type_name = "check_input",
.input_size = sizeof(struct check_input),
};
static const struct check_input_type *check_input_types[] = {
&check_input_type,
};
const struct check_output_type check_output_type = {
.type_name = "check_output",
.output_size = sizeof(struct check_output),
.master_ops = &check_output_ops,
.output_construct = &check_output_construct,
};
static const struct check_output_type *check_output_types[] = {
&check_output_type,
};
const struct check_brick_type check_brick_type = {
.type_name = "check_brick",
.brick_size = sizeof(struct check_brick),
.max_inputs = 1,
.max_outputs = 1,
.master_ops = &check_brick_ops,
.aspect_types = check_aspect_types,
.default_input_types = check_input_types,
.default_output_types = check_output_types,
.brick_construct = &check_brick_construct,
};
EXPORT_SYMBOL_GPL(check_brick_type);
////////////////// module init stuff /////////////////////////
int __init init_mars_check(void)
{
MARS_INF("init_check()\n");
return check_register_brick_type();
}
void exit_mars_check(void)
{
MARS_INF("exit_check()\n");
check_unregister_brick_type();
}
#ifndef CONFIG_MARS_HAVE_BIGMODULE
MODULE_DESCRIPTION("MARS check brick");
MODULE_AUTHOR("Thomas Schoebel-Theuer <tst@{schoebel-theuer,1und1}.de>");
MODULE_LICENSE("GPL");
module_init(init_mars_check);
module_exit(exit_mars_check);
#endif