Re: [PATCH v2 2/2] fsnotify: consistent behavior for parent not watching children

From: Greg KH <gregkh@linuxfoundation.org>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Matthew Bobrowski <mbobrowski@mbobrowski.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Jan Kara <jack@suse.cz>, stable <stable@vger.kernel.org>
Subject: Re: [PATCH v2 2/2] fsnotify: consistent behavior for parent not watching children
Date: Thu, 23 Jun 2022 18:09:45 +0200	[thread overview]
Message-ID: <YrSQScmJ5C28cSt2@kroah.com> (raw)
In-Reply-To: <CAOQ4uxiBHzFExCZowFNggn+woOz8vfwK=PZvAnVVBYHvjG-udQ@mail.gmail.com>

On Tue, Jun 21, 2022 at 06:04:33AM +0300, Amir Goldstein wrote:
> On Mon, Jun 20, 2022 at 11:34 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > On Mon, Jun 20, 2022 at 05:16:16PM +0300, Amir Goldstein wrote:
> > > On Wed, May 11, 2022 at 10:02 PM Amir Goldstein <amir73il@gmail.com> wrote:
> > > >
> > > > The logic for handling events on child in groups that have a mark on
> > > > the parent inode, but without FS_EVENT_ON_CHILD flag in the mask is
> > > > duplicated in several places and inconsistent.
> > > >
> > > > Move the logic into the preparation of mark type iterator, so that the
> > > > parent mark type will be excluded from all mark type iterations in that
> > > > case.
> > > >
> > > > This results in several subtle changes of behavior, hopefully all
> > > > desired changes of behavior, for example:
> > > >
> > > > - Group A has a mount mark with FS_MODIFY in mask
> > > > - Group A has a mark with ignore mask that does not survive FS_MODIFY
> > > >   and does not watch children on directory D.
> > > > - Group B has a mark with FS_MODIFY in mask that does watch children
> > > >   on directory D.
> > > > - FS_MODIFY event on file D/foo should not clear the ignore mask of
> > > >   group A, but before this change it does
> > > >
> > > > And if group A ignore mask was set to survive FS_MODIFY:
> > > > - FS_MODIFY event on file D/foo should be reported to group A on account
> > > >   of the mount mark, but before this change it is wrongly ignored
> > > >
> > > > Fixes: 2f02fd3fa13e ("fanotify: fix ignore mask logic for events on child and on dir")
> > > > Reported-by: Jan Kara <jack@suse.com>
> > > > Link: https://lore.kernel.org/linux-fsdevel/20220314113337.j7slrb5srxukztje@quack3.lan/
> > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> > > > ---
> > >
> > > Greg,
> > >
> > > FYI, this needs the previous commit to apply to 5.18.y:
> >
> > What is "this" here?  What git id?
> 
> Sorry, this commit:
> 
> > > e730558adffb fsnotify: consistent behavior for parent not watching children
> 
> Needs this previous commit:
> 
> > > 14362a254179 fsnotify: introduce mark type iterator
> 
> > > They won't apply to earlier versions and this is a fix for a very minor bug
> > > that existed forever, so no need to bother.
> >
> > So what exactly needs to be applied in what order and to what trees?
> >
> 
> To apply to 5.18.y.

Now queued up, thanks.

> Don't bother trying to apply either to earlier trees.

So the Fixes: tag lied?  No wonder I was confused :)

thanks,

greg k-h