From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Nottingham Date: Wed, 02 Jul 2008 16:26:49 +0000 Subject: Re: triggering udev rules based on the state of udevd Message-Id: <20080702162649.GA24987@nostromo.devel.redhat.com> List-Id: References: <20080702151527.GA22892@nostromo.devel.redhat.com> In-Reply-To: <20080702151527.GA22892@nostromo.devel.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org Kay Sievers (kay.sievers@vrfy.org) said: > > There doesn't seem to be a good happy medium that allows for degraded assembly > > when needed, but normal assembly in most cases. One potential way to do this > > would be to queue events such as these RAID-handling events as 'idle', or > > 'end of queue', such that they are always run at the end of queue after other > > events have run. Is that sort of thing possible? > > What would be a "queue"? How would you define one? The event queue... basically just a push an event to 'last'. > Can't you run a "all I need is there" - check with every matching > device, and make sure, you serialize/lock things properly, and only > the last device/event would have all needed requirements and trigger > the action, all earlier would just need to give up. The s390 stuff > does things like that with the "collect" extra, Ubuntu has a > "watershed" extra, which may do something like you need. watershed just locks to avoid running multiple instances of the same base command; it doesn't actually solve this. Moreover, just saying 'only the last device/event' isn't really proper - how do you tell what is 'last' in the event of a degraded raid array? Bill