Messages in this thread | | | Date | Wed, 30 Oct 2013 15:38:32 -0700 | From | Greg KH <> | Subject | Re: [PATCH] sysfs: move assignment to be under lock in sysfs_remove_dir() |
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On Wed, Oct 30, 2013 at 02:41:16PM -0700, Eric W. Biederman wrote: > One of the particularly problematic things that can happen with sysfs is > that we can get a hotplug event in userspace and then examine sysfs and > not find the attributes of the device because the kernel has not added > them yet. > > Which is a particularly good reason to have a campaign against > independent usage of device_create_file and device_remove_file in the > device users.
I have been working on that over the past few months, there are now default attribute groups for all things, and those are used to create the files _before_ the hotplug event goes to userspace. I still have more work to do to clean this up, but my goal is to remove device_create_file() entirely, although we still have some work to go for the platform driver case, which will take some time.
But we will get there eventually, it's a problem that has to be fixed as more and more people hit this with multi-core, fast systems these days.
> At which point really the right thing to do when we delete a directory > is to WARN and be very grumpy if there are any attributes in the > directory we were removing.
We tried this once, and it was a mess. But that was a long time ago, maybe it's better now, I'll look and see...
thanks,
greg k-h
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