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/*
* iSCSI daemon event handler
*
* Copyright (C) 2004 Dmitry Yusupov, Alex Aizman
* Copyright (C) 2006 Mike Christie
* Copyright (C) 2006 Red Hat, Inc. All rights reserved.
* maintained by open-iscsi@googlegroups.com
*
* Originally based on:
* (C) 2004 FUJITA Tomonori <tomof@acm.org>
*
* 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.
*
* See the file COPYING included with this distribution for more details.
*/
#include <stdlib.h>
#include <errno.h>
#include <poll.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/signalfd.h>
#include <unistd.h>
#include "mgmt_ipc.h"
#include "iscsi_ipc.h"
#include "sysfs.h"
#include "iscsid.h"
#include "log.h"
#include "iscsi_ipc.h"
#include "actor.h"
#include "initiator.h"
#include "iscsi_err.h"
static unsigned int reap_count;
/* track pid of reload fork, while running */
static pid_t reload_pid = 0;
static void (*reload_callback)(void);
#define REAP_WAKEUP 1000 /* in millisecs */
void reap_inc(void)
{
reap_count++;
}
/* track the reload process to be reaped, when done */
void reap_track_reload_process(pid_t reload_proc_pid, void (*reload_done_callback)(void))
{
reload_pid = reload_proc_pid;
reload_callback = reload_done_callback;
reap_inc();
}
void reap_proc(void)
{
int i, max_reaps;
pid_t rc;
/*
* We don't really need reap_count, but calling wait() all the
* time seems excessive.
*/
max_reaps = reap_count;
for (i = 0; i < max_reaps; i++) {
rc = waitpid(0, NULL, WNOHANG);
if (rc > 0) {
if (rc == reload_pid) {
log_debug(6, "reaped reload process");
reload_callback();
}
reap_count--;
log_debug(6, "reaped pid %d, reap_count now %d",
(int)rc, reap_count);
}
}
}
static LIST_HEAD(shutdown_callbacks);
struct shutdown_callback {
struct list_head list;
pid_t pid;
};
int shutdown_callback(pid_t pid)
{
struct shutdown_callback *cb;
cb = calloc(1, sizeof(*cb));
if (!cb)
return ENOMEM;
INIT_LIST_HEAD(&cb->list);
cb->pid = pid;
log_debug(1, "adding %d for shutdown cb", pid);
list_add_tail(&cb->list, &shutdown_callbacks);
return 0;
}
static void shutdown_notify_pids(void)
{
struct shutdown_callback *cb;
list_for_each_entry(cb, &shutdown_callbacks, list) {
log_debug(1, "Killing %d", cb->pid);
kill(cb->pid, SIGTERM);
}
}
static int shutdown_wait_pids(void)
{
struct shutdown_callback *cb, *tmp;
list_for_each_entry_safe(cb, tmp, &shutdown_callbacks, list) {
/*
* the proc reaper could clean it up, so wait for any
* sign that it is gone.
*/
if (waitpid(cb->pid, NULL, WNOHANG)) {
log_debug(1, "%d done", cb->pid);
list_del(&cb->list);
free(cb);
}
}
return list_empty(&shutdown_callbacks);
}
#define POLL_CTRL 0
#define POLL_IPC 1
#define POLL_ALARM 2
#define POLL_MAX 3
static volatile int event_loop_stop;
static queue_task_t *shutdown_qtask;
void event_loop_exit(queue_task_t *qtask)
{
shutdown_qtask = qtask;
event_loop_stop = 1;
}
void event_loop(struct iscsi_ipc *ipc, int control_fd, int mgmt_ipc_fd)
{
struct pollfd poll_array[POLL_MAX];
int res, has_shutdown_children = 0;
sigset_t sigset;
int sig_fd;
/* Mask off SIGALRM so we can recv it via signalfd */
sigemptyset(&sigset);
sigaddset(&sigset, SIGALRM);
sigprocmask(SIG_SETMASK, &sigset, NULL);
sig_fd = signalfd(-1, &sigset, SFD_NONBLOCK);
if (sig_fd == -1) {
log_error("signalfd failed: %m");
return;
}
poll_array[POLL_CTRL].fd = control_fd;
poll_array[POLL_CTRL].events = POLLIN;
poll_array[POLL_IPC].fd = mgmt_ipc_fd;
poll_array[POLL_IPC].events = POLLIN;
poll_array[POLL_ALARM].fd = sig_fd;
poll_array[POLL_ALARM].events = POLLIN;
event_loop_stop = 0;
while (1) {
if (event_loop_stop) {
if (!has_shutdown_children) {
has_shutdown_children = 1;
shutdown_notify_pids();
}
if (shutdown_wait_pids())
break;
}
/* Runs actors and may set alarm for future actors */
actor_poll();
res = poll(poll_array, POLL_MAX, reap_count ? REAP_WAKEUP : -1);
if (res > 0) {
log_debug(6, "poll result %d", res);
if (poll_array[POLL_CTRL].revents)
ipc->ctldev_handle();
if (poll_array[POLL_IPC].revents) {
switch (ipc->auth_type) {
case ISCSI_IPC_AUTH_UID:
mgmt_ipc_handle_uid_only(mgmt_ipc_fd);
break;
default:
mgmt_ipc_handle(mgmt_ipc_fd);
break;
}
}
if (poll_array[POLL_ALARM].revents) {
struct signalfd_siginfo si;
if (read(sig_fd, &si, sizeof(si)) == -1) {
log_error("got sigfd read() error, errno (%d), "
"exiting", errno);
break;
} else {
log_debug(1, "Poll was woken by an alarm");
}
}
} else if (res < 0) {
if (errno == EINTR) {
log_debug(1, "event_loop interrupted");
} else {
log_error("got poll() error (%d), errno (%d), "
"exiting", res, errno);
break;
}
}
reap_proc();
/*
* flush sysfs cache since kernel objs may
* have changed as a result of handling op
*/
sysfs_cleanup();
}
if (shutdown_qtask)
mgmt_ipc_write_rsp(shutdown_qtask, ISCSI_SUCCESS);
close(sig_fd);
sigprocmask(SIG_UNBLOCK, &sigset, NULL);
}
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