[PATCH v2 0/2] mm/swap: enhance swap cluster allocation checks

[Hui Zhu <hui.zhu@linux.dev>]

From: Hui Zhu <zhuhui@kylinos.cn>

This series enhances safety and debugging for swap cluster allocation
paths in mm/swapfile.c.

Patch 1 adds a VM_WARN_ON in isolate_lock_cluster() to verify that
full clusters (which should already have allocated tables) are not
processed by swap_cluster_alloc_table().

Patch 2 adds lockdep_assert_held for si->global_cluster_lock on non-SSD
devices and adjusts the assertion order to match the actual lock
acquisition sequence.

Changelog:
v2:
According to the comments of YoungJun Park, Kairui Song and Chris Li,
change acquire locks in swap_reclaim_work() to adds a VM_WARN_ON in
isolate_lock_cluster().
According to the comments of YoungJun Park, add code in patch 2 to Change
the order of lockdep_assert_held() to match the actual lock acquisition
order.

Hui Zhu (2):
  mm/swap: Add VM_WARN_ON to isolate_lock_cluster()
  mm/swap: Add lockdep for si->global_cluster_lock in
    swap_cluster_alloc_table()

 mm/swapfile.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

-- 
2.43.0