Hi Wolfram,

On Jan 19, 2015, at 20:55 , Wolfram Sang [off-list ref] wrote:

Back in the days, sysfs seemed to have refcounting issues and subsystems
needed a completion to be safe. This is not the case anymore, so I2C can
get rid of this code. There is noone else besides I2C doing something
like this currently (checked with the attached coccinelle script which
checks if a release function exists and if it contains a completion).

I have been digging through the history of linux.git and
linux-history.git and found that e.g. w1 used to have such a mechanism
and also simply removed it later.

Some more info from Greg Kroah-Hartman:
"Having that call "wait" for the other release call to happen is really
old, as Jean points out, from 2003.  We have "fixed" sysfs since then to
detach the files from the devices easier, we used to have some nasy
reference count issues in that area."

And some testing from Jean Delvare which matches my results:
"However I just tested unloading an i2c bus driver while its adapter's
new_device attribute was opened and rmmod returned immediately. So it
doesn't look like accessing sysfs attributes actually takes a reference
to the underlying i2c_adapter."

Let's get rid of this code before really nobody knows/understands
anymore what this was for and if it has a subtle use.

Hehe, rather obliquely tested by me too :)

Please save the reference counter hackers sanity and merge this :)

Reported-by: Pantelis Antoniou <redacted>
Signed-off-by: Wolfram Sang <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jean Delvare <redacted>
Cc: Julia Lawall <redacted>
?

Regards

? Pantelis