On Thu, 2018-07-26 at 06:35 -0700, Tejun Heo wrote:
> Making removal asynchronous this way sometimes causes issues because
> whether the user sees the device released or not is racy.
> kernfs/sysfs have mechanisms to deal with these cases - remove_self
> and kernfs_break_active_protection(). Have you looked at those?
Hello Tejun,
The call stack in the patch description shows that sdev_store_delete() is
involved in the deadlock. The implementation of that function is as follows:
static ssize_t
sdev_store_delete(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
if (device_remove_file_self(dev, attr))
scsi_remove_device(to_scsi_device(dev));
return count;
};
device_remove_file_self() calls sysfs_remove_file_self() and that last
function calls kernfs_remove_self(). In other words, kernfs_remove_self()
is already being used. Please let me know if I misunderstood your comment.
Thanks,
Bart.
