linux-kernel - Re: overlayfs vs. fscrypt

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Message-ID: <15244624.W7e5yEypHC@blindfold>
Date:   Wed, 13 Mar 2019 21:33:10 +0100
From:   Richard Weinberger <richard@....at>
To:     Amir Goldstein <amir73il@...il.com>
Cc:     Miklos Szeredi <miklos@...redi.hu>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        linux-fscrypt@...r.kernel.org,
        overlayfs <linux-unionfs@...r.kernel.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Paul Lawrence <paullawrence@...gle.com>
Subject: Re: overlayfs vs. fscrypt

Am Mittwoch, 13. März 2019, 15:26:54 CET schrieb Amir Goldstein:
> IMO, the best thing for UBIFS to do would be to modify fscrypt to support
> opting out of the revalidate behavior, IWO, sanitize your hack to an API.

Given the WTF/s rate this thread has, this might me a good option.
Actually people already asked me how to disable this feature because
they saw no use of it.
Being able to delete encrypted files looks good on the feature list but in
reality it has very few users but causes confusion, IMHO.

I propose a new fscrypt_operations flag, FS_CFLG_NO_CRYPT_FNAMES.
If this flag is set, a) fscrypt_setup_filename() will return -EPERM if
no key is found.
And b) __fscrypt_prepare_lookup() will not attach fscrypt_d_ops to the dentry.

Eric, what do you think?

Thanks,
//richard