On Thu, Jun 27, 2024 at 09:45:45PM -0700, Christoph Hellwig wrote: > On Thu, Jun 27, 2024 at 09:50:50PM +0100, Daniel Golle wrote: > > Add notifier block to notify other subsystems about the addition or > > removal of block devices. > > Notification for what? I really hate the concept of random modular > code being able to hook into device discovery / partition scanning. Adding a dedicated notification interface (instead of using block internals in the nvmem driver) has been requested in a previous review by Bart Van Assche: https://patchwork.kernel.org/comment/25771998/ Quote from that previous review comment: >>> Why to add this functionality to the block layer instead of somewhere >>> in the drivers/ directory? >> >> Simply because we need notifications about appearing and disappearing >> block devices, or a way to iterate over all block devices in a system. >> For both there isn't currently any other interface than using a >> class_interface for that, and that requires access to &block_class >> which is considered a block subsystem internal. > > That's an argument for adding an interface to the block layer that > implements this functionality but not for adding this code in the block > layer. --- So that's what I did consequently. Using the notification interface the NVMEM driver can live in drivers/nvmem/ and doesn't need to be using block internals. > And not actually having a user for it is a complete no-go. > The user will be the nvmem provider, you can see the code in earlier versions of the patchset where I had included it: https://patchwork.kernel.org/project/linux-block/patch/96554d6b4d9fa72f936c2c476eb0b023cdd60a64.1717031992.git.daniel@xxxxxxxxxxxxxx/ Being another subsystem I thought it'd be better to deal with the block related things first, and once that has been sorted out I will move on to add the NVMEM driver and make the necessary changes for using it on eMMC. Thank you for taking a look at this. Let me know if anything else is not clear or needs to be changed. Cheers Daniel
