Re: [RFC PATCH] scsi: libsas: fix WARN on device removal

From: John Garry
Date: Fri Nov 18 2016 - 04:03:18 EST

On 18/11/2016 01:53, Dan Williams wrote:
On Thu, Nov 17, 2016 at 7:23 AM, John Garry <john.garry@xxxxxxxxxx> wrote:
On 11/11/2016 08:49, wangyijing wrote:

I have not seen the flutter issue. I am just trying to solve the
horrible WARN dump.
However I do understand that there may be a issue related to how we
queue the events; there was a recent attempt to fix this, but it came to

We found libsas hotplug several problems:
1. sysfs warning calltrace(like the case you found);

Maybe you can then review my patch.

I did it, I think your solution to fix the sysfs calltrace issue is ok,
and what I worried about is we still need to fix
the rest issues. So it's better if we could fix all issues one time.

@Maintainers, would you be willing to accept this patch as an interim fix
for the dastardly WARN while we try to fix the flutter issue?

To me this adds a bug to quiet a benign, albeit noisy, warning.

What is the bug which is being added?

And it's a very noisy warning, as in 6K lines on the console when an expander is unplugged.