From: Amir Goldstein <amir73il@gmail.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>,
Al Viro <viro@zeniv.linux.org.uk>,
Dave Chinner <david@fromorbit.com>,
overlayfs <linux-unionfs@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH v3 6/6] ovl: add ovl_fadvise()
Date: Mon, 27 Aug 2018 22:05:00 +0300 [thread overview]
Message-ID: <CAOQ4uxjE-XtGC=D-C+329snTs7u7bGgcrns2N-rR34ZXAdm=0g@mail.gmail.com> (raw)
In-Reply-To: <20180827185250.GB29056@redhat.com>
On Mon, Aug 27, 2018 at 9:52 PM Vivek Goyal <vgoyal@redhat.com> wrote:
>
> On Mon, Aug 27, 2018 at 03:56:04PM +0300, Amir Goldstein wrote:
> > Implement stacked fadvise to fix syscalls readahead(2) and fadvise64(2)
> > on an overlayfs file.
> >
> > Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
> > Fixes: d1d04ef8572b ("ovl: stack file ops")
> > Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> > ---
> > fs/overlayfs/file.c | 18 ++++++++++++++++++
> > 1 file changed, 18 insertions(+)
> >
> > diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
> > index a4acd84591d4..42d2d034d85c 100644
> > --- a/fs/overlayfs/file.c
> > +++ b/fs/overlayfs/file.c
> > @@ -331,6 +331,23 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
> > return ret;
> > }
> >
> > +int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
> > +{
> > + struct fd real;
> > + int ret;
> > +
> > + ret = ovl_real_fdget(file, &real);
> > + if (ret)
> > + return ret;
> > +
> > + /* XXX: do we need mounter credentials? */
>
> Given we are switching creds to mounter for rest of the file operations,
> so I would think we need to do it here as well to be consistent with
> this security model.
>
Yeh, I guess so, although I did not see any security checks in
fadvise64(2) syscall. readahead(2) at least checks for FMODE_READ
on the open file fadvise doesn't even bother with that...
Miklos, let me know if you want me to add override_creds or will
you add it yourself.
Thanks,
Amir.
next prev parent reply other threads:[~2018-08-27 22:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1535374564-8257-1-git-send-email-amir73il@gmail.com>
2018-08-27 12:55 ` [PATCH v3 1/6] ovl: respect FIEMAP_FLAG_SYNC flag Amir Goldstein
[not found] ` <1535374564-8257-5-git-send-email-amir73il@gmail.com>
2018-08-27 13:56 ` [PATCH v3 4/6] vfs: add the fadvise() file operation Steve French
[not found] ` <1535374564-8257-7-git-send-email-amir73il@gmail.com>
2018-08-27 18:52 ` [PATCH v3 6/6] ovl: add ovl_fadvise() Vivek Goyal
2018-08-27 19:05 ` Amir Goldstein [this message]
2018-08-27 19:29 ` Miklos Szeredi
2019-12-28 5:49 ` Andreas Dilger
2019-12-28 10:10 ` Amir Goldstein
[not found] ` <1535374564-8257-6-git-send-email-amir73il@gmail.com>
2018-08-27 23:30 ` [PATCH v3 5/6] vfs: implement readahead(2) using POSIX_FADV_WILLNEED Dave Chinner
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='CAOQ4uxjE-XtGC=D-C+329snTs7u7bGgcrns2N-rR34ZXAdm=0g@mail.gmail.com' \
--to=amir73il@gmail.com \
--cc=david@fromorbit.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-unionfs@vger.kernel.org \
--cc=miklos@szeredi.hu \
--cc=vgoyal@redhat.com \
--cc=viro@zeniv.linux.org.uk \
/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).