All of
 help / color / mirror / Atom feed
From: Gabriel Krisman Bertazi <>
To: Eric Biggers <>
Cc:, Theodore Ts'o <>,
Subject: Re: [PATCH v4] ext4: only allow test_dummy_encryption when supported
Date: Thu, 19 May 2022 16:56:06 -0400	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <> (Eric Biggers's message of "Thu, 19 May 2022 13:44:37 -0700")

Eric Biggers <> writes:

> From: Eric Biggers <>
> Make the test_dummy_encryption mount option require that the encrypt
> feature flag be already enabled on the filesystem, rather than
> automatically enabling it.  Practically, this means that "-O encrypt"
> will need to be included in MKFS_OPTIONS when running xfstests with the
> test_dummy_encryption mount option.  (ext4/053 also needs an update.)
> Moreover, as long as the preconditions for test_dummy_encryption are
> being tightened anyway, take the opportunity to start rejecting it when
> !CONFIG_FS_ENCRYPTION rather than ignoring it.
> The motivation for requiring the encrypt feature flag is that:
> - Having the filesystem auto-enable feature flags is problematic, as it
>   bypasses the usual sanity checks.  The specific issue which came up
>   recently is that in kernel versions where ext4 supports casefold but
>   not encrypt+casefold (v5.1 through v5.10), the kernel will happily add
>   the encrypt flag to a filesystem that has the casefold flag, making it
>   unmountable -- but only for subsequent mounts, not the initial one.
>   This confused the casefold support detection in xfstests, causing
>   generic/556 to fail rather than be skipped.
> - The xfstests-bld test runners (kvm-xfstests et al.) already use the
>   required mkfs flag, so they will not be affected by this change.  Only
>   users of test_dummy_encryption alone will be affected.  But, this
>   option has always been for testing only, so it should be fine to
>   require that the few users of this option update their test scripts.
> - f2fs already requires it (for its equivalent feature flag).
> Signed-off-by: Eric Biggers <>

Makes sense to me and code looks good.  Please add:

Reviewed-by: Gabriel Krisman Bertazi <>

Gabriel Krisman Bertazi

  reply	other threads:[~2022-05-19 20:56 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-19 20:44 [PATCH v4] ext4: only allow test_dummy_encryption when supported Eric Biggers
2022-05-19 20:56 ` Gabriel Krisman Bertazi [this message]
2022-05-22  2:31 ` Theodore Ts'o

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.