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	Eric Dumazet is reporting addition on 0 problem at rds_tcp_tune(), for
delayed works queued in rds_wq might be invoked after a net namespace's
refcount already reached 0.
Since rds_tcp_exit_net() from cleanup_net() calls flush_workqueue(rds_wq),
it is guaranteed that we can instead use maybe_get_net() from delayed work
functions until rds_tcp_exit_net() returns.
Note that I'm not convinced that all works which might access a net
namespace are already queued in rds_wq by the moment rds_tcp_exit_net()
calls flush_workqueue(rds_wq). If some race is there, rds_tcp_exit_net()
will fail to wait for work functions, and kmem_cache_free() could be
called from net_free() before maybe_get_net() is called from
rds_tcp_tune().
Reported-by: Eric Dumazet <edumazet@google.com>
Fixes: 3a58f13a88 ("net: rds: acquire refcount on TCP sockets")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/41d09faf-bc78-1a87-dfd1-c6d1b5984b61@I-love.SAKURA.ne.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
		
	
			
		
			
				
	
	
		
			98 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			98 lines
		
	
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _RDS_TCP_H
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#define _RDS_TCP_H
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#define RDS_TCP_PORT	16385
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struct rds_tcp_incoming {
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	struct rds_incoming	ti_inc;
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	struct sk_buff_head	ti_skb_list;
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};
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struct rds_tcp_connection {
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	struct list_head	t_tcp_node;
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	bool			t_tcp_node_detached;
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	struct rds_conn_path	*t_cpath;
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	/* t_conn_path_lock synchronizes the connection establishment between
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	 * rds_tcp_accept_one and rds_tcp_conn_path_connect
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	 */
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	struct mutex		t_conn_path_lock;
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	struct socket		*t_sock;
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	void			*t_orig_write_space;
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	void			*t_orig_data_ready;
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	void			*t_orig_state_change;
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	struct rds_tcp_incoming	*t_tinc;
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	size_t			t_tinc_hdr_rem;
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	size_t			t_tinc_data_rem;
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	/* XXX error report? */
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	struct work_struct	t_conn_w;
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	struct work_struct	t_send_w;
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	struct work_struct	t_down_w;
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	struct work_struct	t_recv_w;
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	/* for info exporting only */
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	struct list_head	t_list_item;
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	u32			t_last_sent_nxt;
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	u32			t_last_expected_una;
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	u32			t_last_seen_una;
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};
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struct rds_tcp_statistics {
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	uint64_t	s_tcp_data_ready_calls;
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	uint64_t	s_tcp_write_space_calls;
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	uint64_t	s_tcp_sndbuf_full;
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	uint64_t	s_tcp_connect_raced;
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	uint64_t	s_tcp_listen_closed_stale;
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};
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/* tcp.c */
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bool rds_tcp_tune(struct socket *sock);
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void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp);
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void rds_tcp_reset_callbacks(struct socket *sock, struct rds_conn_path *cp);
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void rds_tcp_restore_callbacks(struct socket *sock,
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			       struct rds_tcp_connection *tc);
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u32 rds_tcp_write_seq(struct rds_tcp_connection *tc);
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u32 rds_tcp_snd_una(struct rds_tcp_connection *tc);
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u64 rds_tcp_map_seq(struct rds_tcp_connection *tc, u32 seq);
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extern struct rds_transport rds_tcp_transport;
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void rds_tcp_accept_work(struct sock *sk);
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int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
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			__u32 scope_id);
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/* tcp_connect.c */
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int rds_tcp_conn_path_connect(struct rds_conn_path *cp);
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void rds_tcp_conn_path_shutdown(struct rds_conn_path *conn);
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void rds_tcp_state_change(struct sock *sk);
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/* tcp_listen.c */
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struct socket *rds_tcp_listen_init(struct net *net, bool isv6);
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void rds_tcp_listen_stop(struct socket *sock, struct work_struct *acceptor);
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void rds_tcp_listen_data_ready(struct sock *sk);
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int rds_tcp_accept_one(struct socket *sock);
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void rds_tcp_keepalive(struct socket *sock);
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void *rds_tcp_listen_sock_def_readable(struct net *net);
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/* tcp_recv.c */
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int rds_tcp_recv_init(void);
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void rds_tcp_recv_exit(void);
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void rds_tcp_data_ready(struct sock *sk);
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int rds_tcp_recv_path(struct rds_conn_path *cp);
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void rds_tcp_inc_free(struct rds_incoming *inc);
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int rds_tcp_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
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/* tcp_send.c */
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void rds_tcp_xmit_path_prepare(struct rds_conn_path *cp);
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void rds_tcp_xmit_path_complete(struct rds_conn_path *cp);
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int rds_tcp_xmit(struct rds_connection *conn, struct rds_message *rm,
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		 unsigned int hdr_off, unsigned int sg, unsigned int off);
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void rds_tcp_write_space(struct sock *sk);
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/* tcp_stats.c */
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DECLARE_PER_CPU(struct rds_tcp_statistics, rds_tcp_stats);
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#define rds_tcp_stats_inc(member) rds_stats_inc_which(rds_tcp_stats, member)
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unsigned int rds_tcp_stats_info_copy(struct rds_info_iterator *iter,
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				     unsigned int avail);
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#endif
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