[PATCH] add uevent_helper control in /sys/kernel/ (0f76e5ac) · Commits · 戴 / test

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:

Kay Sievers <kay.sievers@suse.de> Signed-off-by:

Greg Kroah-Hartman <gregkh@suse.de>

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,

Admin message