On Thu, Nov 07, 2024 at 05:05:13AM +0900, Krzysztof Wilczyński wrote: > Hello, > > > Several drivers need to dynamically calculate the size of an binary > > attribute. Currently this is done by assigning attr->size from the > > is_bin_visible() callback. > > > > This has drawbacks: > > * It is not documented. > > * A single attribute can be instantiated multiple times, overwriting the > > shared size field. > > * It prevents the structure to be moved to read-only memory. > > > > Introduce a new dedicated callback to calculate the size of the > > attribute. > > Would it be possible to have a helper that when run against a specific > kobject reference, then it would refresh or re-run the size callbacks? > > We have an use case where we resize BARs on demand via sysfs, and currently > the only way to update the size of each resource sysfs object is to remove > and added them again, which is a bit crude, and can also be unsafe. How is it unsafe? > Hence the question. > > There exist the sysfs_update_groups(), but the BAR resource sysfs objects > are currently, at least not yet, added to any attribute group. then maybe they should be added to one :) thanks, greg k-h
