[PATCH 3/5] libfs: Add generic function for setting dentry_ops

[Eric Biggers]

On Wed, Sep 23, 2020 at 01:01:49AM +0000, Daniel Rosenberg wrote:
> This adds a function to set dentry operations at lookup time that will
> work for both encrypted files and casefolded filenames.

"encrypted files" => "encrypted filenames"

> 
> A filesystem that supports both features simultaneously can use this
> function during lookup preperations to set up its dentry operations once
> fscrypt no longer does that itself.

"preperations" => "preparations"

> 
> Currently the casefolding dentry operation are always set because the
> feature is toggleable on empty directories. Since we don't know what
> set of functions we'll eventually need, and cannot change them later,
> we add just add them.

"are always set" => "are always set if the filesystem defines an encoding"

> +/**
> + * generic_set_encrypted_ci_d_ops - helper for setting d_ops for given dentry
> + * @dentry:	dentry to set ops on
> + *
> + * This function sets the dentry ops for the given dentry to handle both
> + * casefolding and encryption of the dentry name.
> + */

But it also seems that some of the information in the commit message should go
into this comment so that it isn't lost.  It's not clear to someone reading this
code what "handling encryption of the dentry name" means (hint: it doesn't
actually mean handling encryption...), and why setting the casefolding
operations isn't conditional on IS_CASEFOLDED(dir).

- Eric