From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [PATCH 04/13] sysfs: Simplify sysfs_chmod_file semantics Date: Tue, 3 Nov 2009 22:55:47 -0600 Message-ID: <20091104045547.GA774@us.ibm.com> References: <1257249429-12384-4-git-send-email-ebiederm@xmission.com> <20091104024332.GA27639@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Greg Kroah-Hartman , Kay Sievers , Greg KH , linux-kernel@vger.kernel.org, Tejun Heo , Cornelia Huck , linux-fsdevel@vger.kernel.org, Eric Dumazet , Benjamin LaHaise , "Eric W. Biederman" To: "Eric W. Biederman" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Quoting Eric W. Biederman (ebiederm@xmission.com): > "Serge E. Hallyn" writes: > > > Quoting Eric W. Biederman (ebiederm@xmission.com): > >> From: Eric W. Biederman > >> > >> Currently every caller of sysfs_chmod_file happens at either > >> file creation time to set a non-default mode or in response > >> to a specific user requested space change in policy. Making > >> timestamps of when the chmod happens and notification of > >> a file changing mode uninteresting. > > > > But these changes can occur by togging values in sysfs files > > (i.e. f71805f.c), right? Is this (specifically not doing inotify) > > definately uncontroversial? > > The fs_notify_change was not introduced to deliberately support > a feature but as a side effect of other cleanups. So there > is no indication that anyone cares about inotify support. > > > I can't exactly picture an admin sitting there watching > > nautilus for a sysfs file to become writeable, but could > > imagine some site's automation getting hung... Or am I way > > off base? > > I would be stunned if the shell script in the automation that writes > to a sysfs file to make things writeable doesn't on it's next line > kick off whatever needs it to be writable. > > With no benefit to using inotify and with only a handful of sysfs > files affected I don't expect this change to break anything in > userspace and I have been happily running with it for a year or so on > all of our machines at work with no one problems. > > The reason I am making the change is that the goal of this patchset is > to get sysfs to act like any other distributed filesystem in linux, > and to use the same interfaces in roughly the same ways as other > distributed filesystems. Unfortunately there is not a good interface > for distributed filesystems to support inotify or I would use it. > > Eric Ok - I personally agree, but I know there are admins out there with very different mindsets from mine Acked-by: Serge Hallyn -serge