sbd-common.c
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sbd-common.c
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	/*
	* Copyright (C) 2013 Lars Marowsky-Bree <lmb@suse.com>
	*
	* 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 software 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.
	*/

	#include "sbd.h"
	#include <sys/reboot.h>
	#include <sys/types.h>
	#include <pwd.h>

	#ifdef _POSIX_MEMLOCK
	# include <sys/mman.h>
	#endif

	/* Tunable defaults: */
	#if defined(__s390__) \|\| defined(__s390x__)
	unsigned long timeout_watchdog = 15;
	int timeout_msgwait = 30;
	#else
	unsigned long timeout_watchdog = 5;
	int timeout_msgwait = 10;
	#endif
	unsigned long timeout_watchdog_warn = 3;
	int timeout_allocate = 2;
	int timeout_loop = 1;
	int timeout_io = 3;
	int timeout_startup = 120;

	int watchdog_use = 1;
	int watchdog_set_timeout = 1;
	unsigned long timeout_watchdog_crashdump = 240;
	int skip_rt = 0;
	int debug = 0;
	int debug_mode = 0;
	char *watchdogdev = NULL;
	char * local_uname;

	/* Global, non-tunable variables: */
	int sector_size = 0;
	int watchdogfd = -1;
	int servant_health = 0;

	/const char devname;*/
	const char *cmdname;

	void
	usage(void)
	{
	fprintf(stderr,
	"Shared storage fencing tool.\n"
	"Syntax:\n"
	" %s <options> <command> <cmdarguments>\n"
	"Options:\n"
	"-d <devname> Block device to use (mandatory; can be specified up to 3 times)\n"
	"-h Display this help.\n"
	"-n <node> Set local node name; defaults to uname -n (optional)\n"
	"\n"
	"-R Do NOT enable realtime priority (debugging only)\n"
	"-W Use watchdog (recommended) (watch only)\n"
	"-w <dev> Specify watchdog device (optional) (watch only)\n"
	"-T Do NOT initialize the watchdog timeout (watch only)\n"
	"-S <0\|1> Set start mode if the node was previously fenced (watch only)\n"
	"-p <path> Write pidfile to the specified path (watch only)\n"
	"-v Enable some verbose debug logging (optional)\n"
	"\n"
	"-1 <N> Set watchdog timeout to N seconds (optional, create only)\n"
	"-2 <N> Set slot allocation timeout to N seconds (optional, create only)\n"
	"-3 <N> Set daemon loop timeout to N seconds (optional, create only)\n"
	"-4 <N> Set msgwait timeout to N seconds (optional, create only)\n"
	"-5 <N> Warn if loop latency exceeds threshold (optional, watch only)\n"
	" (default is 3, set to 0 to disable)\n"
	"-C <N> Watchdog timeout to set before crashdumping (def: 240s, optional)\n"
	"-I <N> Async IO read timeout (defaults to 3 * loop timeout, optional)\n"
	"-s <N> Timeout to wait for devices to become available (def: 120s)\n"
	"-t <N> Dampening delay before faulty servants are restarted (optional)\n"
	" (default is 5, set to 0 to disable)\n"
	"-F <N> # of failures before a servant is considered faulty (optional)\n"
	" (default is 1, set to 0 to disable)\n"
	"-P Check Pacemaker quorum and node health (optional, watch only)\n"
	"-Z Enable trace mode. WARNING: UNSAFE FOR PRODUCTION!\n"
	"Commands:\n"
	#if SUPPORT_SHARED_DISK
	"create initialize N slots on <dev> - OVERWRITES DEVICE!\n"
	"list List all allocated slots on device, and messages.\n"
	"dump Dump meta-data header from device.\n"
	"allocate <node>\n"
	" Allocate a slot for node (optional)\n"
	"message <node> (test\|reset\|off\|clear\|exit)\n"
	" Writes the specified message to node's slot.\n"
	#endif
	"watch Loop forever, monitoring own slot\n"
	, cmdname);
	}

	int
	watchdog_init_interval(void)
	{
	int timeout = timeout_watchdog;

	if (watchdogfd < 0) {
	return 0;
	}


	if (watchdog_set_timeout == 0) {
	cl_log(LOG_INFO, "NOT setting watchdog timeout on explicit user request!");
	return 0;
	}

	if (ioctl(watchdogfd, WDIOC_SETTIMEOUT, &timeout) < 0) {
	cl_perror( "WDIOC_SETTIMEOUT"
	": Failed to set watchdog timer to %u seconds.",
	timeout);
	cl_log(LOG_CRIT, "Please validate your watchdog configuration!");
	cl_log(LOG_CRIT, "Choose a different watchdog driver or specify -T to skip this if you are completely sure.");
	return -1;
	} else {
	cl_log(LOG_INFO, "Set watchdog timeout to %u seconds.",
	timeout);
	}
	return 0;
	}

	int
	watchdog_tickle(void)
	{
	if (watchdogfd >= 0) {
	if (write(watchdogfd, "", 1) != 1) {
	cl_perror("Watchdog write failure: %s!",
	watchdogdev);
	return -1;
	}
	}
	return 0;
	}

	int
	watchdog_init(void)
	{
	if (watchdogfd < 0 && watchdogdev != NULL) {
	watchdogfd = open(watchdogdev, O_WRONLY);
	if (watchdogfd >= 0) {
	cl_log(LOG_NOTICE, "Using watchdog device '%s'", watchdogdev);
	if ((watchdog_init_interval() < 0)
	\|\| (watchdog_tickle() < 0)) {
	return -1;
	}
	}else{
	cl_perror("Cannot open watchdog device '%s'", watchdogdev);
	return -1;
	}
	}
	return 0;
	}

	void
	watchdog_close(bool disarm)
	{
	if (watchdogfd < 0) {
	return;
	}

	if (disarm) {
	int r;
	int flags = WDIOS_DISABLECARD;;

	/* Explicitly disarm it */
	r = ioctl(watchdogfd, WDIOC_SETOPTIONS, &flags);
	if (r < 0) {
	cl_perror("Failed to disable hardware watchdog %s", watchdogdev);
	}

	/* To be sure, use magic close logic, too */
	for (;;) {
	if (write(watchdogfd, "V", 1) > 0) {
	break;
	}
	cl_perror("Cannot disable watchdog device %s", watchdogdev);
	}
	}

	if (close(watchdogfd) < 0) {
	cl_perror("Watchdog close(%d) failed", watchdogfd);
	}

	watchdogfd = -1;
	}

	/* This duplicates some code from linux/ioprio.h since these are not included
	* even in linux-kernel-headers. Sucks. See also
	* /usr/src/linux/Documentation/block/ioprio.txt and ioprio_set(2) */
	extern int sys_ioprio_set(int, int, int);
	int ioprio_set(int which, int who, int ioprio);
	inline int ioprio_set(int which, int who, int ioprio)
	{
	return syscall(__NR_ioprio_set, which, who, ioprio);
	}

	enum {
	IOPRIO_CLASS_NONE,
	IOPRIO_CLASS_RT,
	IOPRIO_CLASS_BE,
	IOPRIO_CLASS_IDLE,
	};

	enum {
	IOPRIO_WHO_PROCESS = 1,
	IOPRIO_WHO_PGRP,
	IOPRIO_WHO_USER,
	};

	#define IOPRIO_BITS (16)
	#define IOPRIO_CLASS_SHIFT (13)
	#define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1)

	#define IOPRIO_PRIO_CLASS(mask) ((mask) >> IOPRIO_CLASS_SHIFT)
	#define IOPRIO_PRIO_DATA(mask) ((mask) & IOPRIO_PRIO_MASK)
	#define IOPRIO_PRIO_VALUE(class, data) (((class) << IOPRIO_CLASS_SHIFT) \| data)

	static unsigned char
	sbd_stack_hogger(unsigned char * inbuf, int kbytes)
	{
	unsigned char buf[1024];

	if(kbytes <= 0) {
	return HOG_CHAR;
	}

	if (inbuf == NULL) {
	memset(buf, HOG_CHAR, sizeof(buf));
	} else {
	memcpy(buf, inbuf, sizeof(buf));
	}

	if (kbytes > 0) {
	return sbd_stack_hogger(buf, kbytes-1);
	} else {
	return buf[sizeof(buf)-1];
	}
	}

	static void
	sbd_malloc_hogger(int kbytes)
	{
	int j;
	void**chunks;
	int chunksize = 1024;

	if(kbytes <= 0) {
	return;
	}

	/*
	* We could call mallopt(M_MMAP_MAX, 0) to disable it completely,
	* but we've already called mlockall()
	*
	* We could also call mallopt(M_TRIM_THRESHOLD, -1) to prevent malloc
	* from giving memory back to the system, but we've already called
	* mlockall(MCL_FUTURE), so there's no need.
	*/

	chunks = malloc(kbytes * sizeof(void *));
	if (chunks == NULL) {
	cl_log(LOG_WARNING, "Could not preallocate chunk array");
	return;
	}

	for (j=0; j < kbytes; ++j) {
	chunks[j] = malloc(chunksize);
	if (chunks[j] == NULL) {
	cl_log(LOG_WARNING, "Could not preallocate block %d", j);

	} else {
	memset(chunks[j], 0, chunksize);
	}
	}

	for (j=0; j < kbytes; ++j) {
	free(chunks[j]);
	}

	free(chunks);
	}

	static void sbd_memlock(int stackgrowK, int heapgrowK)
	{

	#ifdef _POSIX_MEMLOCK
	/*
	* We could call setrlimit(RLIMIT_MEMLOCK,...) with a large
	* number, but the mcp runs as root and mlock(2) says:
	*
	* Since Linux 2.6.9, no limits are placed on the amount of memory
	* that a privileged process may lock, and this limit instead
	* governs the amount of memory that an unprivileged process may
	* lock.
	*/
	if (mlockall(MCL_CURRENT\|MCL_FUTURE) >= 0) {
	cl_log(LOG_INFO, "Locked ourselves in memory");

	/* Now allocate some extra pages (MCL_FUTURE will ensure they stay around) */
	sbd_malloc_hogger(heapgrowK);
	sbd_stack_hogger(NULL, stackgrowK);

	} else {
	cl_perror("Unable to lock ourselves into memory");
	}

	#else
	cl_log(LOG_ERR, "Unable to lock ourselves into memory");
	#endif
	}

	void
	sbd_make_realtime(int priority, int stackgrowK, int heapgrowK)
	{
	if(priority < 0) {
	return;
	}

	#ifdef SCHED_RR
	{
	int pcurrent = 0;
	int pmin = sched_get_priority_min(SCHED_RR);
	int pmax = sched_get_priority_max(SCHED_RR);

	if (priority == 0) {
	priority = pmax;
	} else if (priority < pmin) {
	priority = pmin;
	} else if (priority > pmax) {
	priority = pmax;
	}

	pcurrent = sched_getscheduler(0);
	if (pcurrent < 0) {
	cl_perror("Unable to get scheduler priority");

	} else if(pcurrent < priority) {
	struct sched_param sp;

	memset(&sp, 0, sizeof(sp));
	sp.sched_priority = priority;

	if (sched_setscheduler(0, SCHED_RR, &sp) < 0) {
	cl_perror("Unable to set scheduler priority to %d", priority);
	} else {
	cl_log(LOG_INFO, "Scheduler priority is now %d", priority);
	}
	}
	}
	#else
	cl_log(LOG_ERR, "System does not support updating the scheduler priority");
	#endif

	sbd_memlock(heapgrowK, stackgrowK);
	}

	void
	maximize_priority(void)
	{
	if (skip_rt) {
	cl_log(LOG_INFO, "Not elevating to realtime (-R specified).");
	return;
	}

	sbd_make_realtime(0, 256, 256);

	if (ioprio_set(IOPRIO_WHO_PROCESS, getpid(),
	IOPRIO_PRIO_VALUE(IOPRIO_CLASS_RT, 1)) != 0) {
	cl_perror("ioprio_set() call failed.");
	}
	}

	void
	sysrq_init(void)
	{
	FILE* procf;
	int c;
	procf = fopen("/proc/sys/kernel/sysrq", "r");
	if (!procf) {
	cl_perror("cannot open /proc/sys/kernel/sysrq for read.");
	return;
	}
	if (fscanf(procf, "%d", &c) != 1) {
	cl_perror("Parsing sysrq failed");
	c = 0;
	}
	fclose(procf);
	if (c == 1)
	return;
	/* 8 for debugging dumps of processes,
	128 for reboot/poweroff */
	c \|= 136;
	procf = fopen("/proc/sys/kernel/sysrq", "w");
	if (!procf) {
	cl_perror("cannot open /proc/sys/kernel/sysrq for writing");
	return;
	}
	fprintf(procf, "%d", c);
	fclose(procf);
	return;
	}

	void
	sysrq_trigger(char t)
	{
	FILE *procf;

	procf = fopen("/proc/sysrq-trigger", "a");
	if (!procf) {
	cl_perror("Opening sysrq-trigger failed.");
	return;
	}
	cl_log(LOG_INFO, "sysrq-trigger: %c\n", t);
	fprintf(procf, "%c\n", t);
	fclose(procf);
	return;
	}


	static void
	do_exit(char kind)
	{
	/* TODO: Turn debug_mode into a bit field? Delay + kdump for example */
	const char *reason = NULL;

	if (kind == 'c') {
	cl_log(LOG_NOTICE, "Initiating kdump");

	} else if (debug_mode == 1) {
	cl_log(LOG_WARNING, "Initiating kdump instead of panicing the node (debug mode)");
	kind = 'c';
	}

	if (debug_mode == 2) {
	cl_log(LOG_WARNING, "Shutting down SBD instead of panicing the node (debug mode)");
	watchdog_close(true);
	exit(0);
	}

	if (debug_mode == 3) {
	/* Give the system some time to flush logs to disk before rebooting. */
	cl_log(LOG_WARNING, "Delaying node panic by 10s (debug mode)");

	watchdog_close(true);
	sync();

	sleep(10);
	}

	switch(kind) {
	case 'b':
	reason = "reboot";
	break;
	case 'c':
	reason = "crashdump";
	break;
	case 'o':
	reason = "off";
	break;
	default:
	reason = "unknown";
	break;
	}

	cl_log(LOG_EMERG, "Rebooting system: %s", reason);
	sync();

	if(kind == 'c') {
	watchdog_close(true);
	sysrq_trigger(kind);

	} else {
	watchdog_close(false);
	sysrq_trigger(kind);
	if (reboot((kind == 'o')?RB_POWER_OFF:RB_AUTOBOOT) < 0) {
	cl_perror("%s failed", (kind == 'o')?"Poweroff":"Reboot");
	}
	}

	exit(1);
	}

	void
	do_crashdump(void)
	{
	do_exit('c');
	}

	void
	do_reset(void)
	{
	do_exit('b');
	}

	void
	do_off(void)
	{
	do_exit('o');
	}

	/*
	* Change directory to the directory our core file needs to go in
	* Call after you establish the userid you're running under.
	*/
	int
	sbd_cdtocoredir(void)
	{
	int rc;
	static const char *dir = NULL;

	if (dir == NULL) {
	dir = CRM_CORE_DIR;
	}
	if ((rc=chdir(dir)) < 0) {
	int errsave = errno;
	cl_perror("Cannot chdir to [%s]", dir);
	errno = errsave;
	}
	return rc;
	}

	pid_t
	make_daemon(void)
	{
	pid_t pid;
	const char * devnull = "/dev/null";

	pid = fork();
	if (pid < 0) {
	cl_log(LOG_ERR, "%s: could not start daemon\n",
	cmdname);
	cl_perror("fork");
	exit(1);
	}else if (pid > 0) {
	return pid;
	}

	qb_log_ctl(QB_LOG_STDERR, QB_LOG_CONF_ENABLED, QB_FALSE);

	/* This is the child; ensure privileges have not been lost. */
	maximize_priority();
	sysrq_init();

	umask(022);
	close(0);
	(void)open(devnull, O_RDONLY);
	close(1);
	(void)open(devnull, O_WRONLY);
	close(2);
	(void)open(devnull, O_WRONLY);
	sbd_cdtocoredir();
	return 0;
	}

	void
	sbd_get_uname(void)
	{
	struct utsname uname_buf;
	int i;

	if (uname(&uname_buf) < 0) {
	cl_perror("uname() failed?");
	exit(1);
	}

	local_uname = strdup(uname_buf.nodename);

	for (i = 0; i < strlen(local_uname); i++)
	local_uname[i] = tolower(local_uname[i]);
	}


	#define FMT_MAX 256
	void
	sbd_set_format_string(int method, const char *daemon)
	{
	int offset = 0;
	char fmt[FMT_MAX];
	struct utsname res;

	switch(method) {
	case QB_LOG_STDERR:
	break;

	case QB_LOG_SYSLOG:
	if(daemon && strcmp(daemon, "sbd") != 0) {
	offset += snprintf(fmt + offset, FMT_MAX - offset, "%10s: ", daemon);
	}
	break;

	default:
	/* When logging to a file */
	if (uname(&res) == 0) {
	offset +=
	snprintf(fmt + offset, FMT_MAX - offset, "%%t [%d] %s %10s: ", getpid(),
	res.nodename, daemon);
	} else {
	offset += snprintf(fmt + offset, FMT_MAX - offset, "%%t [%d] %10s: ", getpid(), daemon);
	}
	}

	if (debug && method >= QB_LOG_STDERR) {
	offset += snprintf(fmt + offset, FMT_MAX - offset, "(%%-12f:%%5l %%g) %%-7p: %%n: ");
	} else {
	offset += snprintf(fmt + offset, FMT_MAX - offset, "%%g %%-7p: %%n: ");
	}

	if (method == QB_LOG_SYSLOG) {
	offset += snprintf(fmt + offset, FMT_MAX - offset, "%%b");
	} else {
	offset += snprintf(fmt + offset, FMT_MAX - offset, "\t%%b");
	}

	if(offset > 0) {
	qb_log_format_set(method, fmt);
	}
	}

	void
	notify_parent(void)
	{
	pid_t ppid;
	union sigval signal_value;

	memset(&signal_value, 0, sizeof(signal_value));
	ppid = getppid();

	if (ppid == 1) {
	/* Our parent died unexpectedly. Triggering
	* self-fence. */
	cl_log(LOG_WARNING, "Our parent is dead.");
	do_reset();
	}

	switch (servant_health) {
	case pcmk_health_pending:
	case pcmk_health_shutdown:
	case pcmk_health_transient:
	DBGLOG(LOG_INFO, "Not notifying parent: state transient (%d)", servant_health);
	break;

	case pcmk_health_unknown:
	case pcmk_health_unclean:
	case pcmk_health_noquorum:
	DBGLOG(LOG_WARNING, "Notifying parent: UNHEALTHY (%d)", servant_health);
	sigqueue(ppid, SIG_PCMK_UNHEALTHY, signal_value);
	break;

	case pcmk_health_online:
	DBGLOG(LOG_INFO, "Notifying parent: healthy");
	sigqueue(ppid, SIG_LIVENESS, signal_value);
	break;

	default:
	DBGLOG(LOG_WARNING, "Notifying parent: UNHEALTHY %d", servant_health);
	sigqueue(ppid, SIG_PCMK_UNHEALTHY, signal_value);
	break;
	}
	}

	void
	set_servant_health(enum pcmk_health state, int level, char const *format, ...)
	{
	if (servant_health != state) {
	va_list ap;
	int len = 0;
	char *string = NULL;

	servant_health = state;

	va_start(ap, format);
	len = vasprintf (&string, format, ap);

	if(len > 0) {
	cl_log(level, "%s", string);
	}

	va_end(ap);
	free(string);
	}
	}

	bool
	sbd_is_disk(struct servants_list_item *servant)
	{
	if ((servant != NULL) &&
	(servant->devname != NULL) &&
	(servant->devname[0] == '/')) {
	return true;
	}
	return false;
	}

	bool
	sbd_is_cluster(struct servants_list_item *servant)
	{
	if ((servant != NULL) &&
	(servant->devname != NULL) &&
	(strcmp("cluster", servant->devname) == 0)) {
	return true;
	}
	return false;
	}

	bool
	sbd_is_pcmk(struct servants_list_item *servant)
	{
	if ((servant != NULL) &&
	(servant->devname != NULL) &&
	(strcmp("pcmk", servant->devname) == 0)) {
	return true;
	}
	return false;
	}

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