On 2023/5/3 13:37, Qi Zheng wrote: > > +void shrinker_debugfs_remove(struct dentry *debugfs_entry, int debugfs_id) > > +{ > > It would be better to add a check: > > if (!debugfs_entry) > return; > > > + debugfs_remove_recursive(debugfs_entry); > > + ida_free(&shrinker_debugfs_ida, debugfs_id); > > +} As a practical matter, both `debugfs_remove_recursive(NULL)` and `ida_free(_, -1);` are documented as no-ops, see: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/debugfs/inode.c?id=0dd2a6fb1e34d6dcb96806bc6b111388ad324722#n748 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fc82bbf4dede758007763867d0282353c06d1121 Sorry for the late reply (the patch already reached the mainline tree).