On Tue, Sep 08, 2020 at 08:54:35AM -0400, Jeff Layton wrote:
> On Mon, 2020-09-07 at 20:52 -0700, Eric Biggers wrote:
> > On Fri, Sep 04, 2020 at 12:05:24PM -0400, Jeff Layton wrote:
> > > Cephfs (currently) sets this flag early and only fetches the context
> > > later. Eventually we may not need this, but for now it prevents this
> > > warning from popping.
> > >
> > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > > ---
> > > fs/crypto/keysetup.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
> > > index ad64525ec680..3b4ec16fc528 100644
> > > --- a/fs/crypto/keysetup.c
> > > +++ b/fs/crypto/keysetup.c
> > > @@ -567,7 +567,7 @@ int fscrypt_get_encryption_info(struct inode *inode)
> > > const union fscrypt_context *dummy_ctx =
> > > fscrypt_get_dummy_context(inode->i_sb);
> > >
> > > - if (IS_ENCRYPTED(inode) || !dummy_ctx) {
> > > + if (!dummy_ctx) {
> > > fscrypt_warn(inode,
> > > "Error %d getting encryption context",
> > > res);
> >
> > This makes errors reading the encryption xattr of an encrypted inode be ignored
> > when the filesystem is mounted with test_dummy_encryption. That's undesirable.
> >
> > Isn't this change actually no longer needed, now that new inodes will use
> > fscrypt_prepare_new_inode() instead of fscrypt_get_encryption_info()?
>
> No. This is really for when we're reading in a new inode from the MDS.
> We can tell that there is a context present in some of those cases, but
> may not be able to read it yet. That said, it may be possible to pull in
> the context at the point where we set S_ENCRYPTED. I'll take a look.
fscrypt_prepare_new_inode() sets ->i_crypt_info on the new inode.
fscrypt_get_encryption_info() isn't needed after that. If it does get called
anyway, it will be a no-op since it will see fscrypt_has_encryption_key(inode).
And when allocating an in-memory inode for an existing file,
fscrypt_get_encryption_info() shouldn't be called either. It gets called later
by filesystem operations that need the encryption key, usually ->open().
- Eric
