From: Ira Weiny <ira.weiny@intel.com>
To: Jan Kara <jack@suse.cz>
Cc: linux-kernel@vger.kernel.org,
"Darrick J. Wong" <darrick.wong@oracle.com>,
Dan Williams <dan.j.williams@intel.com>,
Dave Chinner <david@fromorbit.com>,
Christoph Hellwig <hch@lst.de>,
"Theodore Y. Ts'o" <tytso@mit.edu>,
Jeff Moyer <jmoyer@redhat.com>,
linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH RFC 2/8] fs/ext4: Disallow verity if inode is DAX
Date: Wed, 15 Apr 2020 12:14:52 -0700 [thread overview]
Message-ID: <20200415191451.GA2305801@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <20200415120002.GE6126@quack2.suse.cz>
On Wed, Apr 15, 2020 at 02:00:02PM +0200, Jan Kara wrote:
> On Mon 13-04-20 21:00:24, ira.weiny@intel.com wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> >
> > 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@intel.com>
> > ---
> > 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@suse.com>
> SUSE Labs, CR
next prev parent reply other threads:[~2020-04-15 19:15 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-14 4:00 [PATCH RFC 0/8] Enable ext4 support for per-file/directory DAX operations ira.weiny
2020-04-14 4:00 ` [PATCH RFC 1/8] fs/ext4: Narrow scope of DAX check in setflags ira.weiny
2020-04-15 11:45 ` Jan Kara
2020-04-14 4:00 ` [PATCH RFC 2/8] fs/ext4: Disallow verity if inode is DAX ira.weiny
2020-04-15 11:58 ` Jan Kara
2020-04-15 12:00 ` Jan Kara
2020-04-15 15:55 ` Theodore Y. Ts'o
2020-04-15 19:21 ` Ira Weiny
2020-04-15 19:14 ` Ira Weiny [this message]
2020-04-16 1:29 ` Eric Biggers
2020-04-16 3:48 ` Ira Weiny
2020-04-15 20:34 ` Ira Weiny
2020-04-14 4:00 ` [PATCH RFC 3/8] fs/ext4: Disallow encryption " ira.weiny
2020-04-15 12:02 ` Jan Kara
2020-04-15 20:35 ` Ira Weiny
2020-04-15 16:03 ` Theodore Y. Ts'o
2020-04-15 17:27 ` Dan Williams
2020-04-15 19:54 ` Ira Weiny
2020-04-21 18:41 ` Ira Weiny
2020-04-21 18:56 ` Darrick J. Wong
2020-04-14 4:00 ` [PATCH RFC 4/8] fs/ext4: Introduce DAX inode flag ira.weiny
2020-04-15 12:08 ` Jan Kara
2020-04-15 20:39 ` Ira Weiny
2020-04-16 10:32 ` Jan Kara
2020-04-16 18:01 ` Theodore Y. Ts'o
2020-04-16 16:25 ` Darrick J. Wong
2020-04-16 22:33 ` Ira Weiny
2020-04-16 22:49 ` Darrick J. Wong
2020-04-17 0:37 ` Ira Weiny
2020-04-17 1:57 ` Darrick J. Wong
2020-04-17 2:20 ` Ira Weiny
2020-04-17 6:43 ` Andreas Dilger
2020-04-17 17:19 ` Ira Weiny
2020-04-14 4:00 ` [PATCH RFC 5/8] fs/ext4: Make DAX mount option a tri-state ira.weiny
2020-04-15 12:51 ` Jan Kara
2020-04-14 4:00 ` [PATCH RFC 6/8] fs/ext4: Update ext4_should_use_dax() ira.weiny
2020-04-15 13:58 ` Jan Kara
2020-04-17 17:16 ` Ira Weiny
2020-04-14 4:00 ` [PATCH RFC 7/8] fs/ext4: Only change S_DAX on inode load ira.weiny
2020-04-15 14:03 ` Jan Kara
2020-04-17 17:18 ` Ira Weiny
2020-04-14 4:00 ` [PATCH RFC 8/8] Documentation/dax: Update DAX enablement for ext4 ira.weiny
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200415191451.GA2305801@iweiny-DESK2.sc.intel.com \
--to=ira.weiny@intel.com \
--cc=dan.j.williams@intel.com \
--cc=darrick.wong@oracle.com \
--cc=david@fromorbit.com \
--cc=hch@lst.de \
--cc=jack@suse.cz \
--cc=jmoyer@redhat.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).