Re: [PATCH 2/2] loop: Perform __loop_clr_fd() after disk->open_mutex is dropped

[Bart Van Assche <bvanassche@acm.org>]

On 9/16/26 3:47 PM, Tetsuo Handa wrote:
> Please stop stealing my series

No, I'm not stealing your work. I credited you in the first patch with a
Suggested-by.

> and stop proposing broken series.

I think we disagree. My view is that your series is broken.
Additionally, I have explained multiple times in detail why I think
your series is broken but you chose to ignore my feedback.

> Since .post_release is called entirely outside of disk->open_mutex, multiple
> non-final close() threads can concurrently invoke lo_post_release() and race
> inside __loop_clr_fd() without any serialization.

This is wrong. The .release() and .post_release() callbacks are only
called once. The following code from fs/file_table.c illustrates this:

void fput(struct file *file)
{
	if (unlikely(file_ref_put(&file->f_ref)))
		__fput_deferred(file);
}

/* the real guts of fput() - releasing the last reference to file */
static void __fput(struct file *file)
{
	[ ... ]
	if (file->f_op->release)
		file->f_op->release(inode, file);
	[ ... ]
}

Thanks,

Bart.