Re: WARNING: suspicious RCU usage in rds_loop_conn_alloc

From: Sowmini Varadhan
Date: Mon Feb 12 2018 - 11:10:13 EST


> rcu_scheduler_active = 2, debug_locks = 1
> 1 lock held by syzkaller563791/4086:
> #0: (rcu_read_lock){....}, at: [<00000000bf5db0e6>]
> __rds_conn_create+0xe46/0x1b50 net/rds/connection.c:218
>

the rcu_read_lock() was added by ebeeb1ad9b. After we add that,
everything in the rcu read critical section needs to use GFP_ATOMIC
to avoid sleeping. I'll look into this fix.

--Sowmini