Commit 50704e03 authored by Leon Romanovsky's avatar Leon Romanovsky Committed by Jason Gunthorpe
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RDMA/umem: Restore lockdep check while downgrading lock 



Lockdep engine handles correctly downgrade of locks and it simply
incorrect to disable lockdep checks prior to calling mmu_notifier.

Remove lockdep_off and ensure locks correctness.

Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent e1f540c3

drivers/infiniband/core/umem_odp.c

+0 −6
Original line number Diff line number Diff line
@@ -431,13 +431,7 @@ int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem, 
		atomic_set(&context->notifier_count, 0);

		INIT_HLIST_NODE(&context->mn.hlist);

		context->mn.ops = &ib_umem_notifiers;

		/*

		 * Lock-dep detects a false positive for mmap_sem vs.

		 * umem_rwsem, due to not grasping downgrade_write correctly.

		 */

		lockdep_off();

		ret_val = mmu_notifier_register(&context->mn, mm);

		lockdep_on();

		if (ret_val) {

			pr_err("Failed to register mmu_notifier %d\n", ret_val);

			ret_val = -EBUSY;