Re: [PATCH 0/9] Generate uevents for all DM events
From: Mike Snitzer
Date: Mon Oct 03 2016 - 15:29:27 EST
On Mon, Oct 03 2016 at 3:22pm -0400,
Andy Grover <agrover@xxxxxxxxxx> wrote:
> Hi Mike and GregKH,
> I want a way to get devicemapper events without using the DM ioctl,
> because that requires creating a thread to sleep in the ioctl for each
> dm device I want events from.
> It would seem like using uevents and KOBJ_CHANGE would be a good way
> to do this, but Mike said that the uevent maintainers (Greg that's
> you?) did not think this was a good idea?
I think you might be confusing me with Alasdair?
> If so, I was hoping you could talk a little more about why -- grep
> shows KOBJ_CHANGE used all over, but its usage is not documented in
> kobject.txt. In any case I can update kobject.txt with some more
> The following patchset may be appliable if you're actually ok with
> using KOBJ_CHANGE for dm events, or if not, then I'll look to rework
> it to use a dm-specific genetlink approach.
I don't have strong opinions on this. If Greg is OK with your approach
we can move forward (bringing Alasdair into the discussion too).
That said I haven't looked at your changes. But your subjects make for
a confusing mix of "uevent" and "event". Could just be that I'm too far
removed from the details to appreciate what is happening.
> Andy Grover (9):
> dm: Do not export dm_send_uevents
> dm: Move multipath-specific stuff out of dm-uevent.c
> dm: Inline dm_build_path_uevent into dm_path_uevent
> dm: Update dm-uevent.txt
> dm: Rename dm_build_uevent to dm_uevent_build
> dm: Rename dm_event_add to dm_event_queue
> dm: Implement dm_uevent_add()
> dm: Generate uevents for thin targets
> dm: Generate uevents for other targets
> Documentation/device-mapper/dm-uevent.txt | 54 ++++++++++++++--
> drivers/md/dm-cache-target.c | 5 +-
> drivers/md/dm-log-userspace-base.c | 8 ++-
> drivers/md/dm-log.c | 1 +
> drivers/md/dm-mpath.c | 56 ++++++++++++++++
> drivers/md/dm-raid1.c | 1 +
> drivers/md/dm-snap.c | 1 +
> drivers/md/dm-thin.c | 3 +
> drivers/md/dm-uevent.c | 102 ++++++++++--------------------
> drivers/md/dm-uevent.h | 30 +++++++--
> drivers/md/dm.c | 3 +-
> include/linux/device-mapper.h | 3 +-
> 12 files changed, 180 insertions(+), 87 deletions(-)