/* Disk protection for HP/DELL machines.
 *
 * Copyright 2008 Eric Piel
 * Copyright 2009 Pavel Machek <pavel@ucw.cz>
 * Copyright 2012 Sonal Santan
 * Copyright 2014 Pali Rohár <pali.rohar@gmail.com>
 *
 * GPLv2.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include <signal.h>
#include <sys/mman.h>
#include <sched.h>
#include <syslog.h>

static int noled;
static char unload_heads_path[64];
static char device_path[32];
static const char app_name[] = "FREE FALL";

static int set_unload_heads_path(char *device)
{
	if (strlen(device) <= 5 || strncmp(device, "/dev/", 5) != 0)
		return -EINVAL;
	strncpy(device_path, device, sizeof(device_path) - 1);

	snprintf(unload_heads_path, sizeof(unload_heads_path) - 1,
				"/sys/block/%s/device/unload_heads", device+5);
	return 0;
}

static int valid_disk(void)
{
	int fd = open(unload_heads_path, O_RDONLY);

	if (fd < 0) {
		perror(unload_heads_path);
		return 0;
	}

	close(fd);
	return 1;
}

static void write_int(char *path, int i)
{
	char buf[1024];
	int fd = open(path, O_RDWR);

	if (fd < 0) {
		perror("open");
		exit(1);
	}

	sprintf(buf, "%d", i);

	if (write(fd, buf, strlen(buf)) != strlen(buf)) {
		perror("write");
		exit(1);
	}

	close(fd);
}

static void set_led(int on)
{
	if (noled)
		return;
	write_int("/sys/class/leds/hp::hddprotect/brightness", on);
}

static void protect(int seconds)
{
	const char *str = (seconds == 0) ? "Unparked" : "Parked";

	write_int(unload_heads_path, seconds*1000);
	syslog(LOG_INFO, "%s %s disk head\n", str, device_path);
}

static int on_ac(void)
{
	/* /sys/class/power_supply/AC0/online */
	return 1;
}

static int lid_open(void)
{
	/* /proc/acpi/button/lid/LID/state */
	return 1;
}

static void ignore_me(int signum)
{
	protect(0);
	set_led(0);
}

int main(int argc, char **argv)
{
	int fd, ret;
	struct stat st;
	struct sched_param param;

	if (argc == 1)
		ret = set_unload_heads_path("/dev/sda");
	else if (argc == 2)
		ret = set_unload_heads_path(argv[1]);
	else
		ret = -EINVAL;

	if (ret || !valid_disk()) {
		fprintf(stderr, "usage: %s <device> (default: /dev/sda)\n",
				argv[0]);
		exit(1);
	}

	fd = open("/dev/freefall", O_RDONLY);
	if (fd < 0) {
		perror("/dev/freefall");
		return EXIT_FAILURE;
	}

	if (stat("/sys/class/leds/hp::hddprotect/brightness", &st))
		noled = 1;

	if (daemon(0, 0) != 0) {
		perror("daemon");
		return EXIT_FAILURE;
	}

	openlog(app_name, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);

	param.sched_priority = sched_get_priority_max(SCHED_FIFO);
	sched_setscheduler(0, SCHED_FIFO, &param);
	mlockall(MCL_CURRENT|MCL_FUTURE);

	signal(SIGALRM, ignore_me);

	for (;;) {
		unsigned char count;

		ret = read(fd, &count, sizeof(count));
		alarm(0);
		if ((ret == -1) && (errno == EINTR)) {
			/* Alarm expired, time to unpark the heads */
			continue;
		}

		if (ret != sizeof(count)) {
			perror("read");
			break;
		}

		protect(21);
		set_led(1);
		if (1 || on_ac() || lid_open())
			alarm(2);
		else
			alarm(20);
	}

	closelog();
	close(fd);
	return EXIT_SUCCESS;
}
den' name='id' value='433e19cf33d34bb6751c874a9c00980552fe508c'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Dexuan Cui &lt;decui@microsoft.com&gt;</td><td class='right'>2017-01-28 11:46:02 -0700</td></tr>
<tr><th>committer</th><td>Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;</td><td class='right'>2017-01-31 10:59:48 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ax25/Kconfig?id=433e19cf33d34bb6751c874a9c00980552fe508c'>433e19cf33d34bb6751c874a9c00980552fe508c</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/ax25/Kconfig?id=433e19cf33d34bb6751c874a9c00980552fe508c'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=433e19cf33d34bb6751c874a9c00980552fe508c'>ce6547ef2987fbb289fa28f03536328a42781651</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/ax25/Kconfig?id=433e19cf33d34bb6751c874a9c00980552fe508c'>net/ax25/Kconfig</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ax25/Kconfig?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>191e885a2e130e639bb0c8ee350d7047294f2ce6</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/ax25/Kconfig?id=433e19cf33d34bb6751c874a9c00980552fe508c&amp;id2=191e885a2e130e639bb0c8ee350d7047294f2ce6'>diff</a>)</td></tr></table>
<div class='commit-subject'>Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()</div><div class='commit-msg'>Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
added the proper mb(), but removed the test "prev_write_sz &lt; pending_sz"
when making the signal decision.

As a result, the guest can signal the host unnecessarily,
and then the host can throttle the guest because the host
thinks the guest is buggy or malicious; finally the user
running stress test can perceive intermittent freeze of
the guest.

This patch brings back the test, and properly handles the
in-place consumption APIs used by NetVSC (see get_next_pkt_raw(),
put_pkt_raw() and commit_rd_index()).

Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reported-by: Rolf Neugebauer &lt;rolf.neugebauer@docker.com&gt;
Tested-by: Rolf Neugebauer &lt;rolf.neugebauer@docker.com&gt;
Cc: "K. Y. Srinivasan" &lt;kys@microsoft.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: K. Y. Srinivasan &lt;kys@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=433e19cf33d34bb6751c874a9c00980552fe508c'>Diffstat</a> (limited to 'net/ax25/Kconfig')</div><table summary='diffstat' class='diffstat'>