On 06/03, Eric Biggers wrote:
> On Thu, Jun 03, 2021 at 09:50:38AM +0000, Daniel Rosenberg wrote:
> > Older kernels don't support encryption with casefolding. This adds
> > the sysfs entry encrypted_casefold to show support for those combined
> > features. Support for this feature was originally added by
> > commit 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")
> >
> > Fixes: 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")
> > Cc: stable@xxxxxxxxxxxxxxx # v5.11+
> > Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
> > ---
> > fs/f2fs/sysfs.c | 15 +++++++++++++--
> > 1 file changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> > index 09e3f258eb52..6604291a3cdf 100644
> > --- a/fs/f2fs/sysfs.c
> > +++ b/fs/f2fs/sysfs.c
> > @@ -161,6 +161,9 @@ static ssize_t features_show(struct f2fs_attr *a,
> > if (f2fs_sb_has_compression(sbi))
> > len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
> > len ? ", " : "", "compression");
> > + if (f2fs_sb_has_casefold(sbi) && f2fs_sb_has_encrypt(sbi))
> > + len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
> > + len ? ", " : "", "encrypted_casefold");
> > len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s",
> > len ? ", " : "", "pin_file");
> > len += scnprintf(buf + len, PAGE_SIZE - len, "\n");
> > @@ -579,6 +582,7 @@ enum feat_id {
> > FEAT_CASEFOLD,
> > FEAT_COMPRESSION,
> > FEAT_TEST_DUMMY_ENCRYPTION_V2,
> > + FEAT_ENCRYPTED_CASEFOLD,
> > };
>
> Actually looking at it more closely, this patch is wrong.
>
> It only makes sense to declare "encrypted_casefold" as a feature of the
> filesystem implementation, i.e. /sys/fs/f2fs/features/encrypted_casefold.
>
> It does *not* make sense to declare it as a feature of a particular filesystem
> instance, i.e. /sys/fs/f2fs/$disk/features, as it is already implied by the
> filesystem instance having both the encryption and casefold features enabled.
>
> Can we add /sys/fs/f2fs/features/encrypted_casefold only?
wait.. /sys/fs/f2fs/features/encrypted_casefold is on by
CONFIG_FS_ENCRYPTION && CONFIG_UNICODE.
OTOH, /sys/fs/f2fs/$dis/feature_list/encrypted_casefold is on by
on-disk features: F2FS_FEATURE_ENCRYPT and F2FS_FEATURE_CASEFOLD.
>
> - Eric
