On Sat, Apr 29, 2023 at 11:16:14AM +0800, Ming Lei wrote: > OK, looks both Dave and you have same suggestion, and IMO, it isn't hard to > add one interface for notifying FS, and it can be either one s_ops->shutdown() > or shutdown_filesystem(struct super_block *sb). It's not that simple. You need to be able to do that for any device used by a file system, not just s_bdev. This means it needs go into ops passed by the bdev owner, which is also needed to propagate this through stackable devices. I have some work on that, but the way how blkdev_get is called in the generic mount helpers is a such a mess that I've not been happy with the result yet. Let me see if spending extra time with it will allow me to come up with something that doesn't suck. > But the main job should be how this interface is implemented in FS/VFS side, > so it looks one more FS job, and block layer can call shutdown_filesystem() > from del_gendisk() simply. This needs to be called from blk_mark_disk_dead for drivers using that, and from del_gendisk only if GD_DEAD isn't set yet.