On Wed, Apr 15, 2020 at 02:00:02PM +0200, Jan Kara wrote: > On Mon 13-04-20 21:00:24, 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> > > --- > > fs/ext4/verity.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c > > index dc5ec724d889..ce3f9a198d3b 100644 > > --- a/fs/ext4/verity.c > > +++ b/fs/ext4/verity.c > > @@ -113,6 +113,9 @@ static int ext4_begin_enable_verity(struct file *filp) > > handle_t *handle; > > int err; > > > > + if (WARN_ON_ONCE(IS_DAX(inode))) > > + return -EINVAL; > > + > > Hum, one question, is there a reason for WARN_ON_ONCE()? If I understand > correctly, user could normally trigger this, couldn't he? Ok. I did not think this through but I did think about this. I was following the code from the encryption side which issues a warning and was thinking that would be a good way to alert the user they are doing something wrong... I think you are right about both of them but we also need to put something in the verity, dax, and ... (I can't find a file in Documentation which talks about encryption right off) documentation files.... For verity something like. <quote> Verity and DAX -------------- Verity and DAX are not compatible and attempts to set both of these flags on a file will fail. </quote> And the same thing in the DAX doc? And where would be appropriate for the encrypt doc? Ira > > Honza > > > if (ext4_verity_in_progress(inode)) > > return -EBUSY; > > > > -- > > 2.25.1 > > > -- > Jan Kara <jack@xxxxxxxx> > SUSE Labs, CR
