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Commit 0f76e5ac authored by Kay Sievers's avatar Kay Sievers Committed by Greg Kroah-Hartman
Browse files

[PATCH] add uevent_helper control in /sys/kernel/ 



This deprecates the /proc/sys/kernel/hotplug file, as all
this stuff should be in /sys some day, right? :)
In /sys/kernel/ we have now uevent_seqnum and uevent_helper.
The seqnum is no longer used by udev, as the version for this
kernel depends on netlink which events will never get
out-of-order.

Recent udev versions disable the /sbin/hotplug helper with
an init script, cause it leads to OOM on big boxes by running
hundreds of shells in parallel. It should be done now by:
  echo "" > /sys/kernel/uevent_helper

(Note that "-n" does not work, cause neighter proc nor sysfs
support truncate().)

Signed-off-by: default avatarKay Sievers <kay.sievers@suse.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0296b228

kernel/ksysfs.c

+22 −3
Original line number Diff line number Diff line
@@ -23,11 +23,29 @@ static struct subsys_attribute _name##_attr = \ 
	__ATTR(_name, 0644, _name##_show, _name##_store)



#ifdef CONFIG_HOTPLUG

static ssize_t hotplug_seqnum_show(struct subsystem *subsys, char *page)

/* current uevent sequence number */

static ssize_t uevent_seqnum_show(struct subsystem *subsys, char *page)

{

	return sprintf(page, "%llu\n", (unsigned long long)hotplug_seqnum);

}

KERNEL_ATTR_RO(hotplug_seqnum);

KERNEL_ATTR_RO(uevent_seqnum);



/* uevent helper program, used during early boo */

static ssize_t uevent_helper_show(struct subsystem *subsys, char *page)

{

	return sprintf(page, "%s\n", hotplug_path);

}

static ssize_t uevent_helper_store(struct subsystem *subsys, const char *page, size_t count)

{

	if (count+1 > HOTPLUG_PATH_LEN)

		return -ENOENT;

	memcpy(hotplug_path, page, count);

	hotplug_path[count] = '\0';

	if (count && hotplug_path[count-1] == '\n')

		hotplug_path[count-1] = '\0';

	return count;

}

KERNEL_ATTR_RW(uevent_helper);

#endif



#ifdef CONFIG_KEXEC
@@ -45,7 +63,8 @@ EXPORT_SYMBOL_GPL(kernel_subsys); 


static struct attribute * kernel_attrs[] = {

#ifdef CONFIG_HOTPLUG

	&hotplug_seqnum_attr.attr,

	&uevent_seqnum_attr.attr,

	&uevent_helper_attr.attr,

#endif

#ifdef CONFIG_KEXEC

	&crash_notes_attr.attr,