Messages in this thread | | | From | Logan Gunthorpe <> | Date | Wed, 20 Jan 2021 12:50:43 -0700 | Subject | Re: [PATCH 1/3] cdev: Finish the cdev api with queued mode support |
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On 2021-01-20 12:38 p.m., Dan Williams wrote: > ...common reference count handling scenarios were addressed, but the > shutdown-synchronization problem was only mentioned as something driver > developers need to be aware in the following note: > > NOTE: This guarantees that associated sysfs callbacks are not running > or runnable, however any cdevs already open will remain and their fops > will still be callable even after this function returns. > > Remove that responsibility from driver developers with the concept of a > 'queued' mode for cdevs.
I find the queued name confusing. What's being queued?
> +static const struct file_operations cdev_queued_fops = { > + .owner = THIS_MODULE, > + .open = cdev_queued_open, > + .unlocked_ioctl = cdev_queued_ioctl, > + .compat_ioctl = compat_ptr_ioctl, > + .llseek = noop_llseek, > +};
Why do we only protect these fops? I'd find it a bit confusing to have ioctl protected from use after del, but not write/read/etc.
Logan
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