Commit f48ed538 authored Jun 28, 2008 by Neil Brown

Close race in md_probe



There is a possible race in md_probe.  If two threads call md_probe
for the same device, then one could exit (having checked that
->gendisk exists) before the other has called kobject_init_and_add,
thus returning an incomplete kobj which will cause problems when
we try to add children to it.

So extend the range of protection of disks_mutex slightly to
avoid this possibility.

Signed-off-by: Neil Brown <neilb@suse.de>

parent 5e96ee65

drivers/md/md.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3359,9 +3359,9 @@ static struct kobject md_probe(dev_t dev, int part, void *data)
		disk->queue = mddev->queue;
		add_disk(disk);
		mddev->gendisk = disk;
		mutex_unlock(&disks_mutex);
		error = kobject_init_and_add(&mddev->kobj, &md_ktype, &disk->dev.kobj,
		"%s", "md");
		mutex_unlock(&disks_mutex);
		if (error)
		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
		disk->disk_name);