dlm: remove lock_sock to avoid scheduling while atomic (d2fee58a) · Commits · 戴 / test

Before this patch, functions save_callbacks and restore_callbacks called function lock_sock and release_sock to prevent other processes from messing with the struct sock while the callbacks were saved and restored. However, function add_sock calls write_lock_bh prior to calling it save_callbacks, which disables preempts. So the call to lock_sock would try to schedule when we can't schedule. Signed-off-by:

Bob Peterson <rpeterso@redhat.com> Signed-off-by:

David Teigland <teigland@redhat.com>

fs/dlm/lowcomms.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -519,24 +519,20 @@ out:
		/* Note: sk_callback_lock must be locked before calling this function. */
		static void save_callbacks(struct connection con, struct sock sk)
		{
		lock_sock(sk);
		con->orig_data_ready = sk->sk_data_ready;
		con->orig_state_change = sk->sk_state_change;
		con->orig_write_space = sk->sk_write_space;
		con->orig_error_report = sk->sk_error_report;
		release_sock(sk);
		}

		static void restore_callbacks(struct connection con, struct sock sk)
		{
		write_lock_bh(&sk->sk_callback_lock);
		lock_sock(sk);
		sk->sk_user_data = NULL;
		sk->sk_data_ready = con->orig_data_ready;
		sk->sk_state_change = con->orig_state_change;
		sk->sk_write_space = con->orig_write_space;
		sk->sk_error_report = con->orig_error_report;
		release_sock(sk);
		write_unlock_bh(&sk->sk_callback_lock);
		}

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