Re: [PATCH v2 02/16] fsnotify: factor helpers fsnotify_dentry() and fsnotify_file()

From: Jan Kara <jack@suse.cz>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Jan Kara <jack@suse.cz>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Matthew Bobrowski <mbobrowski@mbobrowski.org>
Subject: Re: [PATCH v2 02/16] fsnotify: factor helpers fsnotify_dentry() and fsnotify_file()
Date: Wed, 26 Feb 2020 14:59:09 +0100	[thread overview]
Message-ID: <20200226135909.GS10728@quack2.suse.cz> (raw)
In-Reply-To: <CAOQ4uxjRaidKvh=7UBNHZTwfqLne+JXeOkWb0BVsvJep26kFyw@mail.gmail.com>

On Tue 25-02-20 16:27:02, Amir Goldstein wrote:
> On Tue, Feb 25, 2020 at 3:46 PM Jan Kara <jack@suse.cz> wrote:
> >
> > On Mon 17-02-20 15:14:41, Amir Goldstein wrote:
> > > Most of the code in fsnotify hooks is boiler plate of one or the other.
> > >
> > > Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> > > ---
> > >  include/linux/fsnotify.h | 96 +++++++++++++++-------------------------
> > >  1 file changed, 36 insertions(+), 60 deletions(-)
> >
> > Nice cleanup. Just two comments below.
> >
> > > @@ -58,8 +78,6 @@ static inline int fsnotify_path(struct inode *inode, const struct path *path,
> > >  static inline int fsnotify_perm(struct file *file, int mask)
> > >  {
> > >       int ret;
> > > -     const struct path *path = &file->f_path;
> > > -     struct inode *inode = file_inode(file);
> > >       __u32 fsnotify_mask = 0;
> > >
> > >       if (file->f_mode & FMODE_NONOTIFY)
> >
> > I guess you can drop the NONOTIFY check from here. You've moved it to
> > fsnotify_file() and there's not much done in this function to be worth
> > skipping...
> 
> True.
> 
> >
> > > @@ -70,7 +88,7 @@ static inline int fsnotify_perm(struct file *file, int mask)
> > >               fsnotify_mask = FS_OPEN_PERM;
> > >
> > >               if (file->f_flags & __FMODE_EXEC) {
> > > -                     ret = fsnotify_path(inode, path, FS_OPEN_EXEC_PERM);
> > > +                     ret = fsnotify_file(file, FS_OPEN_EXEC_PERM);
> > >
> > >                       if (ret)
> > >                               return ret;
> >
> > Hum, I think we could simplify fsnotify_perm() even further by having:
> >
> >         if (mask & MAY_OPEN) {
> >                 if (file->f_flags & __FMODE_EXEC)
> >                         fsnotify_mask = FS_OPEN_EXEC_PERM;
> >                 else
> >                         fsnotify_mask = FS_OPEN_PERM;
> >         } ...
> >
> 
> But the current code sends both FS_OPEN_EXEC_PERM and FS_OPEN_PERM
> on an open for exec. I believe that is what was discussed when Matthew wrote
> the OPEN_EXEC patches, so existing receivers of OPEN_PERM event on exec
> will not regress..

Ah, my bad. You're right.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR