Re: [PATCH 4/8] vfs: Fold casefolding into vfs

On Mon, Dec 02, 2019 at 09:10:45PM -0800, Daniel Rosenberg wrote:

Ext4 and F2fs are both using casefolding, and they, along with any other
filesystem that adds the feature, will be using identical dentry_ops.
Additionally, those dentry ops interfere with the dentry_ops required
for fscrypt once we add support for casefolding and encryption.
Moving this into the vfs removes code duplication as well as the
complication with encryption.

Currently this is pretty close to just moving the existing f2fs/ext4
code up a level into the vfs, although there is a lot of room for
improvement now.

Signed-off-by: Daniel Rosenberg <redacted>

I'm afraid that such vfs modification is unneeded.

Just a quick glance it seems just can be replaced by introducing some
.d_cmp, .d_hash helpers (or with little modification) and most non-Android
emulated storage files are not casefolded (even in Android).

"those dentry ops interfere with the dentry_ops required for fscrypt",
I don't think it's a real diffculty and it could be done with some
better approach instead.

Thanks,
Gao Xiang