Max Kellermann recently reported psi_group_cpu.tasks[NR_MEMSTALL] is
incorrect in 6.11.9 kernel.
I think the root cause of the recent issue is that since the problematic
commit, bio can be NULL so psi_memstall_leave() could be missed in
z_erofs_submit_queue().
Reported-by: Max Kellermann <max.kellermann@xxxxxxxxx>
Closes: https://lore.kernel.org/r/CAKPOu+8tvSowiJADW2RuKyofL_CSkm_SuyZA7ME5vMLWmL6pqw@xxxxxxxxxxxxxx
Fixes: 9e2f9d34dd12 ("erofs: handle overlapped pclusters out of crafted images properly")
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>