mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git
synced 2026-10-30 05:42:46 +01:00
Gregory Price
249c5ee21a
Add a kselftest for the dax/kmem whole-device "state" sysfs attribute
(/sys/bus/dax/devices/daxX.Y/state), which transitions a kmem-backed
dax device between "unplugged", "online" and "online_movable".
The kselftest also includes a test to demonstrate the force-unbind
does not deadlock - but this is destructive (the dax device can never
be rebound), so it only runs when DAX_KMEM_TEST_UNBIND=1 is set.
Provisioning a devdax device and binding it to kmem needs daxctl/ndctl
out of scope for an in-tree selftest. As the test mutates a device's
memory, the operator opts in by naming it in DAX_KMEM_TEST_DEV (or
"auto" to pick the first kmem-bound device); it SKIPs when unset, when
no device is present, or when the memory cannot be freed to a baseline.
When a device is available it validates the interface contract:
- online / online_movable actually add memory (MemTotal grows),
- online is idempotent,
- switching between online types without unplug is rejected,
- unplug removes memory and the reported state is "unplugged"
- invalid input is rejected,
- unplug and unbind tolerate blocks toggled out-of-band through the
per-block memoryX/state interface.
One specific regression test:
online -> unplug -> online_movable -> unplug
Re-online must re-reserve per-range resources so subsequent unplug
actually offlines and removes instead of silently reporting success
while the memory stays online.
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Gregory Price <[email protected]>
Cc: Alison Schofield <[email protected]>
Cc: Danilo Krummrich <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: David Hildenbrand (Arm) <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pankaj Gupta <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>