Linux-ext4 Archive on lore.kernel.org
 help / color / Atom feed
From: Eric Biggers <ebiggers@kernel.org>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-ext4@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net,
	linux-api@vger.kernel.org, David Howells <dhowells@redhat.com>,
	Theodore Ts'o <tytso@mit.edu>, Jaegeuk Kim <jaegeuk@kernel.org>,
	Victor Hsieh <victorhsieh@google.com>
Subject: Re: [PATCH 1/4] statx: define STATX_ATTR_VERITY
Date: Thu, 7 Nov 2019 14:12:56 -0800
Message-ID: <20191107221255.GB1160@gmail.com> (raw)
In-Reply-To: <20191107014420.GD15212@magnolia>

On Wed, Nov 06, 2019 at 05:44:20PM -0800, Darrick J. Wong wrote:
> On Tue, Oct 29, 2019 at 01:41:38PM -0700, Eric Biggers wrote:
> > From: Eric Biggers <ebiggers@google.com>
> > 
> > Add a statx attribute bit STATX_ATTR_VERITY which will be set if the
> > file has fs-verity enabled.  This is the statx() equivalent of
> > FS_VERITY_FL which is returned by FS_IOC_GETFLAGS.
> > 
> > This is useful because it allows applications to check whether a file is
> > a verity file without opening it.  Opening a verity file can be
> > expensive because the fsverity_info is set up on open, which involves
> > parsing metadata and optionally verifying a cryptographic signature.
> > 
> > This is analogous to how various other bits are exposed through both
> > FS_IOC_GETFLAGS and statx(), e.g. the encrypt bit.
> > 
> > Signed-off-by: Eric Biggers <ebiggers@google.com>
> > ---
> >  include/linux/stat.h      | 3 ++-
> >  include/uapi/linux/stat.h | 2 +-
> >  2 files changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/include/linux/stat.h b/include/linux/stat.h
> > index 765573dc17d659..528c4baad09146 100644
> > --- a/include/linux/stat.h
> > +++ b/include/linux/stat.h
> > @@ -33,7 +33,8 @@ struct kstat {
> >  	 STATX_ATTR_IMMUTABLE |				\
> >  	 STATX_ATTR_APPEND |				\
> >  	 STATX_ATTR_NODUMP |				\
> > -	 STATX_ATTR_ENCRYPTED				\
> > +	 STATX_ATTR_ENCRYPTED |				\
> > +	 STATX_ATTR_VERITY				\
> >  	 )/* Attrs corresponding to FS_*_FL flags */
> >  	u64		ino;
> >  	dev_t		dev;
> > diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
> > index 7b35e98d3c58b1..ad80a5c885d598 100644
> > --- a/include/uapi/linux/stat.h
> > +++ b/include/uapi/linux/stat.h
> > @@ -167,8 +167,8 @@ struct statx {
> >  #define STATX_ATTR_APPEND		0x00000020 /* [I] File is append-only */
> >  #define STATX_ATTR_NODUMP		0x00000040 /* [I] File is not to be dumped */
> >  #define STATX_ATTR_ENCRYPTED		0x00000800 /* [I] File requires key to decrypt in fs */
> > -
> >  #define STATX_ATTR_AUTOMOUNT		0x00001000 /* Dir: Automount trigger */
> > +#define STATX_ATTR_VERITY		0x00100000 /* [I] Verity protected file */
> 
> Any reason why this wasn't 0x2000?

Yes, as Andreas pointed out, the value is chosen to match the corresponding
FS_IOC_GETFLAGS bit, like the other bits above marked [I].

> 
> If there's a manpage update that goes with this, then...
> Acked-by: Darrick J. Wong <darrick.wong@oracle.com>
> 

It's pretty trivial to add it to the statx(2) man page.
I've sent out a patch for comment:
https://lkml.kernel.org/linux-fscrypt/20191107220248.32025-1-ebiggers@kernel.org/

- Eric

  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-29 20:41 [PATCH 0/4] statx: expose the fs-verity bit Eric Biggers
2019-10-29 20:41 ` [PATCH 1/4] statx: define STATX_ATTR_VERITY Eric Biggers
2019-10-30 18:26   ` Andreas Dilger
2019-11-07  1:44   ` Darrick J. Wong
2019-11-07  2:05     ` Andreas Dilger
2019-11-07 22:02     ` [man-pages RFC PATCH] statx.2: document STATX_ATTR_VERITY Eric Biggers
2019-11-08  0:47       ` Darrick J. Wong
2019-11-08  8:23       ` walter harms
2019-11-08 19:35         ` Eric Biggers
2019-11-09 19:34           ` walter harms
2019-11-13 20:31             ` Eric Biggers
2019-11-07 22:12     ` Eric Biggers [this message]
2019-10-29 20:41 ` [PATCH 2/4] ext4: support STATX_ATTR_VERITY Eric Biggers
2019-10-30 18:27   ` Andreas Dilger
2019-10-29 20:41 ` [PATCH 3/4] f2fs: " Eric Biggers
2019-10-29 20:41 ` [PATCH 4/4] docs: fs-verity: mention statx() support Eric Biggers
2019-11-06 21:57 ` [PATCH 0/4] statx: expose the fs-verity bit Eric Biggers
2019-11-13 20:20 ` Eric Biggers

Reply instructions:

You may reply publically 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=20191107221255.GB1160@gmail.com \
    --to=ebiggers@kernel.org \
    --cc=darrick.wong@oracle.com \
    --cc=dhowells@redhat.com \
    --cc=jaegeuk@kernel.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-f2fs-devel@lists.sourceforge.net \
    --cc=linux-fscrypt@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=tytso@mit.edu \
    --cc=victorhsieh@google.com \
    /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

Linux-ext4 Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-ext4/0 linux-ext4/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-ext4 linux-ext4/ https://lore.kernel.org/linux-ext4 \
		linux-ext4@vger.kernel.org
	public-inbox-index linux-ext4

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-ext4


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git