On Tue, May 12, 2020 at 10:43:17PM -0700, ira.weiny@xxxxxxxxx wrote: > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > Verity and DAX are incompatible. Changing the DAX mode due to a verity > flag change is wrong without a corresponding address_space_operations > update. > > Make the 2 options mutually exclusive by returning an error if DAX was > set first. > > (Setting DAX is already disabled if Verity is set first.) > > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > > --- > Changes: > remove WARN_ON_ONCE > Add documentation for DAX/Verity exclusivity > --- > Documentation/filesystems/ext4/verity.rst | 7 +++++++ > fs/ext4/verity.c | 3 +++ > 2 files changed, 10 insertions(+) > > diff --git a/Documentation/filesystems/ext4/verity.rst b/Documentation/filesystems/ext4/verity.rst > index 3e4c0ee0e068..51ab1aa17e59 100644 > --- a/Documentation/filesystems/ext4/verity.rst > +++ b/Documentation/filesystems/ext4/verity.rst > @@ -39,3 +39,10 @@ is encrypted as well as the data itself. > > Verity files cannot have blocks allocated past the end of the verity > metadata. > + > +Verity and DAX > +-------------- > + > +Verity and DAX are not compatible and attempts to set both of these flags on a > +file will fail. > + If you build the documentation, this shows up as its own subsection "2.13. Verity and DAX" alongside "2.12. Verity files", which looks odd. I think you should delete this new subsection header so that this paragraph goes in the existing "Verity files" subsection. Also, Documentation/filesystems/fsverity.rst already mentions DAX (similar to fscrypt.rst). Is it intentional that you added this to the ext4-specific documentation instead? - Eric
