linux-kernel - Re: [PATCH] autofs - fix symlinks aren't checked for expiry

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Date:	Sat, 28 Dec 2013 10:31:54 +0800
From:	Ian Kent <raven@...maw.net>
To:	sedat.dilek@...il.com
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	autofs mailing list <autofs@...r.kernel.org>,
	Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] autofs - fix symlinks aren't checked for expiry

On Fri, 2013-12-27 at 11:53 +0100, Sedat Dilek wrote:
> On Fri, Dec 27, 2013 at 5:32 AM, Ian Kent <raven@...maw.net> wrote:
> 
> Hi,
> 
> saw some typos...

Right, I'm pretty tired, and seem to be so a lot these days.

Andrew, let me fix the typos and re-submit the patch.

> 
> > From: Ian Kent <ikent@...hat.com>
> >
> > The autofs4 module doesn't consider symlinks for expire as it did
> > in the older autofs v3 module (so it's actually a long stnding
> 
> s/stnding/standing
> 
> > regression).
> >
> > The user space daemon has focused on the use of bind mounts instead
> > of symlinks for a long time now and that's why this has not been
> > noticed. But with the future addition of amd map parsing to
> > automount(8), not to mention amd itself (of am-utils), symlink
> > expiry will be needed.
> >
> > The direct and offset mount types can't be symlinks and the tree
> > mounts of version 4 were always real mounts so only indirect
> > mounts need expire symlinks.
> >
> > Since the current users of the autofs4 module haven't reproted
> 
> s/reproted/reported
> 
> - Sedat -
> 
> > this as a problem to date this patch probably isn't a candidate
> > for backport to stable.
> >
> > Signed-off-by: Ian Kent <ikent@...hat.com>
> > ---
> >  fs/autofs4/expire.c  |   14 ++++++++++++++
> >  fs/autofs4/symlink.c |    4 ++++
> >  2 files changed, 18 insertions(+)
> >
> > diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
> > index 3d9d3f5..394e90b 100644
> > --- a/fs/autofs4/expire.c
> > +++ b/fs/autofs4/expire.c
> > @@ -402,6 +402,20 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb,
> >                         goto next;
> >                 }
> >
> > +               if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) {
> > +                       DPRINTK("checking symlink %p %.*s",
> > +                               dentry, (int)dentry->d_name.len, dentry->d_name.name);
> > +                       /*
> > +                        * A symlink can't be "busy" in the usual sense so
> > +                        * just check last used for expire timeout.
> > +                        */
> > +                       if (autofs4_can_expire(dentry, timeout, do_now)) {
> > +                               expired = dentry;
> > +                               goto found;
> > +                       }
> > +                       goto next;
> > +               }
> > +
> >                 if (simple_empty(dentry))
> >                         goto next;
> >
> > diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c
> > index f27c094..1e8ea19 100644
> > --- a/fs/autofs4/symlink.c
> > +++ b/fs/autofs4/symlink.c
> > @@ -14,6 +14,10 @@
> >
> >  static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
> >  {
> > +       struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
> > +       struct autofs_info *ino = autofs4_dentry_ino(dentry);
> > +       if (ino && !autofs4_oz_mode(sbi))
> > +               ino->last_used = jiffies;
> >         nd_set_link(nd, dentry->d_inode->i_private);
> >         return NULL;
> >  }
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> > the body of a message to majordomo@...r.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html


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