On 6/30/26 23:18, Gregory Price wrote: > offline_and_remove_memory() handles a single contiguous range. > > Callers that manage a device composed of several ranges (dax/kmem) > currently have to call it in a loop, which gives up atomicity. > > In addition to pushing rollback logic into the driver, the lack > of atomicity creates a race condition between system daemons trying > to manage the same resource: > > - Manager 1: Offlines memory blocks. Removes device. > ^^^^ > - Manager 2: Detects offline memory blocks, re-onlines them. > > Add offline_and_remove_memory_ranges(), which takes an array of ranges > and processes them as one operation under a single lock_device_hotplug(): > > - Phase 1 offlines every block of every range. > - Phase 2 removes the ranges only if all ranges are offline. > - If any offline fails, the whole operation is reverted. > > This gives callers all-or-nothing semantics for the offline step, so a > failed or interrupted unplug leaves the device in a consistent state. > > This also resolves the battling managers race - the second manager's > operation simply fails when the block is destroyed / cannot be onlined. > > offline_and_remove_memory() becomes a thin wrapper that passes its single > range to the new helper, so the offline/rollback logic lives in one place. > > Suggested-by: David Hildenbrand (Arm) <[email protected]> > Signed-off-by: Gregory Price <[email protected]> > ---
Acked-by: David Hildenbrand (Arm) <[email protected]> -- Cheers, David
