Do you have a sink for USB notifications?

Do you have a sink for USB notifications?

[David Howells]

Hi Eugeniu, Spyridon,

Do you have a consumer program for USB notification events?  I'm would like to
get my general notification queue patches upstream in this merge window, but
it appears that Linus would like there to be userspace consumers first.

Greg pointed me at your patch:

	https://lore.kernel.org/lkml/20190605090556.17792-1-erosca@de.adit-jv.com/

My latest patch set is here:

	https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=notifications-pipe-core

This provides access to keyring, usb and block device notifications.

Thanks,
David

Re: Do you have a sink for USB notifications?

[Eugeniu Rosca]

Hi David,

On Thu, Jan 16, 2020 at 02:16:41PM +0000, David Howells wrote:
> Hi Eugeniu, Spyridon,
> 
> Greg pointed me at your patch:
> 
> 	https://lore.kernel.org/lkml/20190605090556.17792-1-erosca@de.adit-jv.com/

I remember this thread.

> Do you have a consumer program for USB notification events? 

As you might expect, looking at the above patch, we are using
'udevadm monitor' in the development environment. The end user is
making sense of the notifications either via udev daemon or via
a custom libudev-linked application.

> I'm would like to
> get my general notification queue patches upstream in this merge window, but
> it appears that Linus would like there to be userspace consumers first.
> 
> My latest patch set is here:
> 
> 	https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=notifications-pipe-core
> 
> This provides access to keyring, usb and block device notifications.

It's great to see new and creative solutions being proposed in upstream,
especially if those attempt improving system reliability, robustness and
help standardizing the interfaces.

However, to be honest, I am concerned of below:
 - The amount of code [*] I have to compile/link to enable the feature
   (as opposed to ~15 lines of *.c code in the aforementioned patch)
 - No active users
 - No readily available userspace applications to handle the events
 - No complaints from the customers w.r.t. udevd/libudev (no secret, 
   this is what most of the times funds our work and drives the
   industry forward)

I am still ready to offer any help, if needed. TIA!

> 
> Thanks,
> David
> 

[*] git diff --shortstat v5.5-rc3..linux-fs/notifications-pipe-core
    63 files changed, 2505 insertions(+), 106 deletions(-)

-- 
Best Regards,
Eugeniu