Messages in this thread | | | Date | Fri, 02 Nov 2012 18:49:43 +0100 | From | Paolo Bonzini <> | Subject | Re: setting up CDB filters in udev (was Re: [PATCH v2 0/3] block: add queue-private command filter, editable via sysfs) |
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Il 02/11/2012 17:51, Tejun Heo ha scritto: >>> > > What disturbs me is that it's a completely new interface to userland >>> > > and at the same a very limited one at that. So, yeah, it's >>> > > bothersome. I personally would prefer SCM_RIGHTS behavior change + >>> > > hard coded filters per device class. >> > >> > I think hard-coded filters are bad (I prefer to move policy to >> > userspace), and SCM_RIGHTS without a ioctl is out of question, really. > No rule is really absolute. To me, it seems the suggested in-kernel > per-device command code filter is both too big for the given problem
Is it? 150 lines of code? The per-class filters would share the first two patches with this series, add a long list of commands to filter, and the ioctl would be on top of that.
Long lists are better kept in configuration files than in kernel sources; not to mention the higher cost of getting the API wrong for a ioctl vs. sysfs.
> while being too limited for much beyond that.
What are the use cases beyond these? AFAIK these were the first two in ten years or so...
> So, if we can get away > with adding an ioctl, I personally think that would be a better > approach.
I would really prefer to get a green light from Jens/James for per-class filters in the kernel (which are worth a few hundred lines of data) before implementing that.
Paolo
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