On Fri, Sep 04, 2020 at 12:05:26PM -0400, Jeff Layton wrote: > Once we allow encrypted filenames on ceph we'll end up with names that > may have illegal characters in them (embedded '\0' or '/'), or > characters that aren't printable. > > It will be safer to use strings that are printable. It turns out that the > MDS doesn't really care about the length of filenames, so we can just > base64 encode and decode filenames before writing and reading them. > > Lift the base64 implementation that's in fscrypt into lib/. Make fscrypt > select it when it's enabled. > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > --- > fs/crypto/Kconfig | 1 + > fs/crypto/fname.c | 64 ++------------------------------ > include/linux/base64_fname.h | 11 ++++++ > lib/Kconfig | 3 ++ > lib/Makefile | 1 + > lib/base64_fname.c | 71 ++++++++++++++++++++++++++++++++++++ > 6 files changed, 90 insertions(+), 61 deletions(-) > create mode 100644 include/linux/base64_fname.h > create mode 100644 lib/base64_fname.c > I'm still concerned that this functionality is too specific to belong in lib/ at the moment, given that it's not the most commonly used variant of base64. How about keeping these functions in fs/crypto/ for now? You can call them fscrypt_base64_encode() and fscrypt_base64_decode() and export them for ceph to use. > diff --git a/lib/base64_fname.c b/lib/base64_fname.c > new file mode 100644 > index 000000000000..7638c45e4035 > --- /dev/null > +++ b/lib/base64_fname.c > @@ -0,0 +1,71 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Modified base64 encode/decode functions, suitable for use as filename components. > + * > + * Originally lifted from fs/crypto/fname.c > + * > + * Copyright (C) 2015, Jaegeuk Kim > + * Copyright (C) 2015, Eric Biggers > + */ Please don't change the copyright statements. The original file had: * Copyright (C) 2015, Google, Inc. * Copyright (C) 2015, Motorola Mobility - Eric
