RDS: Main header file

RDS's main data structure definitions and exported functions.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 686 insertions, 0 deletions

diff --git a/net/rds/rds.h b/net/rds/rds.h
new file mode 100644
index 000000000000..060400704979
--- /dev/null
+++ b/net/rds/rds.h
@@ -0,0 +1,686 @@
+#ifndef _RDS_RDS_H
+#define _RDS_RDS_H
+
+#include <net/sock.h>
+#include <linux/scatterlist.h>
+#include <linux/highmem.h>
+#include <rdma/rdma_cm.h>
+#include <linux/mutex.h>
+#include <linux/rds.h>
+
+#include "info.h"
+
+/*
+ * RDS Network protocol version
+ */
+#define RDS_PROTOCOL_3_0        0x0300
+#define RDS_PROTOCOL_3_1        0x0301
+#define RDS_PROTOCOL_VERSION    RDS_PROTOCOL_3_1
+#define RDS_PROTOCOL_MAJOR(v)   ((v) >> 8)
+#define RDS_PROTOCOL_MINOR(v)   ((v) & 255)
+#define RDS_PROTOCOL(maj, min)  (((maj) << 8) | min)
+
+/*
+ * XXX randomly chosen, but at least seems to be unused:
+ * #               18464-18768 Unassigned
+ * We should do better.  We want a reserved port to discourage unpriv'ed
+ * userspace from listening.
+ */
+#define RDS_PORT        18634
+
+#ifdef DEBUG
+#define rdsdebug(fmt, args...) pr_debug("%s(): " fmt, __func__ , ##args)
+#else
+/* sigh, pr_debug() causes unused variable warnings */
+static inline void __attribute__ ((format (printf, 1, 2)))
+rdsdebug(char *fmt, ...)
+{
+}
+#endif
+
+/* XXX is there one of these somewhere? */
+#define ceil(x, y) \
+        ({ unsigned long __x = (x), __y = (y); (__x + __y - 1) / __y; })
+
+#define RDS_FRAG_SHIFT  12
+#define RDS_FRAG_SIZE   ((unsigned int)(1 << RDS_FRAG_SHIFT))
+
+#define RDS_CONG_MAP_BYTES      (65536 / 8)
+#define RDS_CONG_MAP_LONGS      (RDS_CONG_MAP_BYTES / sizeof(unsigned long))
+#define RDS_CONG_MAP_PAGES      (PAGE_ALIGN(RDS_CONG_MAP_BYTES) / PAGE_SIZE)
+#define RDS_CONG_MAP_PAGE_BITS  (PAGE_SIZE * 8)
+
+struct rds_cong_map {
+        struct rb_node          m_rb_node;
+        __be32                  m_addr;
+        wait_queue_head_t       m_waitq;
+        struct list_head        m_conn_list;
+        unsigned long           m_page_addrs[RDS_CONG_MAP_PAGES];
+};
+
+
+/*
+ * This is how we will track the connection state:
+ * A connection is always in one of the following
+ * states. Updates to the state are atomic and imply
+ * a memory barrier.
+ */
+enum {
+        RDS_CONN_DOWN = 0,
+        RDS_CONN_CONNECTING,
+        RDS_CONN_DISCONNECTING,
+        RDS_CONN_UP,
+        RDS_CONN_ERROR,
+};
+
+/* Bits for c_flags */
+#define RDS_LL_SEND_FULL        0
+#define RDS_RECONNECT_PENDING   1
+
+struct rds_connection {
+        struct hlist_node       c_hash_node;
+        __be32                  c_laddr;
+        __be32                  c_faddr;
+        unsigned int            c_loopback:1;
+        struct rds_connection   *c_passive;
+
+        struct rds_cong_map     *c_lcong;
+        struct rds_cong_map     *c_fcong;
+
+        struct mutex            c_send_lock;    /* protect send ring */
+        struct rds_message      *c_xmit_rm;
+        unsigned long           c_xmit_sg;
+        unsigned int            c_xmit_hdr_off;
+        unsigned int            c_xmit_data_off;
+        unsigned int            c_xmit_rdma_sent;
+
+        spinlock_t              c_lock;         /* protect msg queues */
+        u64                     c_next_tx_seq;
+        struct list_head        c_send_queue;
+        struct list_head        c_retrans;
+
+        u64                     c_next_rx_seq;
+
+        struct rds_transport    *c_trans;
+        void                    *c_transport_data;
+
+        atomic_t                c_state;
+        unsigned long           c_flags;
+        unsigned long           c_reconnect_jiffies;
+        struct delayed_work     c_send_w;
+        struct delayed_work     c_recv_w;
+        struct delayed_work     c_conn_w;
+        struct work_struct      c_down_w;
+        struct mutex            c_cm_lock;      /* protect conn state & cm */
+
+        struct list_head        c_map_item;
+        unsigned long           c_map_queued;
+        unsigned long           c_map_offset;
+        unsigned long           c_map_bytes;
+
+        unsigned int            c_unacked_packets;
+        unsigned int            c_unacked_bytes;
+
+        /* Protocol version */
+        unsigned int            c_version;
+};
+
+#define RDS_FLAG_CONG_BITMAP    0x01
+#define RDS_FLAG_ACK_REQUIRED   0x02
+#define RDS_FLAG_RETRANSMITTED  0x04
+#define RDS_MAX_ADV_CREDIT      127
+
+/*
+ * Maximum space available for extension headers.
+ */
+#define RDS_HEADER_EXT_SPACE    16
+
+struct rds_header {
+        __be64  h_sequence;
+        __be64  h_ack;
+        __be32  h_len;
+        __be16  h_sport;
+        __be16  h_dport;
+        u8      h_flags;
+        u8      h_credit;
+        u8      h_padding[4];
+        __sum16 h_csum;
+
+        u8      h_exthdr[RDS_HEADER_EXT_SPACE];
+};
+
+/*
+ * Reserved - indicates end of extensions
+ */
+#define RDS_EXTHDR_NONE         0
+
+/*
+ * This extension header is included in the very
+ * first message that is sent on a new connection,
+ * and identifies the protocol level. This will help
+ * rolling updates if a future change requires breaking
+ * the protocol.
+ * NB: This is no longer true for IB, where we do a version
+ * negotiation during the connection setup phase (protocol
+ * version information is included in the RDMA CM private data).
+ */
+#define RDS_EXTHDR_VERSION      1
+struct rds_ext_header_version {
+        __be32                  h_version;
+};
+
+/*
+ * This extension header is included in the RDS message
+ * chasing an RDMA operation.
+ */
+#define RDS_EXTHDR_RDMA         2
+struct rds_ext_header_rdma {
+        __be32                  h_rdma_rkey;
+};
+
+/*
+ * This extension header tells the peer about the
+ * destination <R_Key,offset> of the requested RDMA
+ * operation.
+ */
+#define RDS_EXTHDR_RDMA_DEST    3
+struct rds_ext_header_rdma_dest {
+        __be32                  h_rdma_rkey;
+        __be32                  h_rdma_offset;
+};
+
+#define __RDS_EXTHDR_MAX        16 /* for now */
+
+struct rds_incoming {
+        atomic_t                i_refcount;
+        struct list_head        i_item;
+        struct rds_connection   *i_conn;
+        struct rds_header       i_hdr;
+        unsigned long           i_rx_jiffies;
+        __be32                  i_saddr;
+
+        rds_rdma_cookie_t       i_rdma_cookie;
+};
+
+/*
+ * m_sock_item and m_conn_item are on lists that are serialized under
+ * conn->c_lock.  m_sock_item has additional meaning in that once it is empty
+ * the message will not be put back on the retransmit list after being sent.
+ * messages that are canceled while being sent rely on this.
+ *
+ * m_inc is used by loopback so that it can pass an incoming message straight
+ * back up into the rx path.  It embeds a wire header which is also used by
+ * the send path, which is kind of awkward.
+ *
+ * m_sock_item indicates the message's presence on a socket's send or receive
+ * queue.  m_rs will point to that socket.
+ *
+ * m_daddr is used by cancellation to prune messages to a given destination.
+ *
+ * The RDS_MSG_ON_SOCK and RDS_MSG_ON_CONN flags are used to avoid lock
+ * nesting.  As paths iterate over messages on a sock, or conn, they must
+ * also lock the conn, or sock, to remove the message from those lists too.
+ * Testing the flag to determine if the message is still on the lists lets
+ * us avoid testing the list_head directly.  That means each path can use
+ * the message's list_head to keep it on a local list while juggling locks
+ * without confusing the other path.
+ *
+ * m_ack_seq is an optional field set by transports who need a different
+ * sequence number range to invalidate.  They can use this in a callback
+ * that they pass to rds_send_drop_acked() to see if each message has been
+ * acked.  The HAS_ACK_SEQ flag can be used to detect messages which haven't
+ * had ack_seq set yet.
+ */
+#define RDS_MSG_ON_SOCK         1
+#define RDS_MSG_ON_CONN         2
+#define RDS_MSG_HAS_ACK_SEQ     3
+#define RDS_MSG_ACK_REQUIRED    4
+#define RDS_MSG_RETRANSMITTED   5
+#define RDS_MSG_MAPPED          6
+#define RDS_MSG_PAGEVEC         7
+
+struct rds_message {
+        atomic_t                m_refcount;
+        struct list_head        m_sock_item;
+        struct list_head        m_conn_item;
+        struct rds_incoming     m_inc;
+        u64                     m_ack_seq;
+        __be32                  m_daddr;
+        unsigned long           m_flags;
+
+        /* Never access m_rs without holding m_rs_lock.
+         * Lock nesting is
+         *  rm->m_rs_lock
+         *   -> rs->rs_lock
+         */
+        spinlock_t              m_rs_lock;
+        struct rds_sock         *m_rs;
+        struct rds_rdma_op      *m_rdma_op;
+        rds_rdma_cookie_t       m_rdma_cookie;
+        struct rds_mr           *m_rdma_mr;
+        unsigned int            m_nents;
+        unsigned int            m_count;
+        struct scatterlist      m_sg[0];
+};
+
+/*
+ * The RDS notifier is used (optionally) to tell the application about
+ * completed RDMA operations. Rather than keeping the whole rds message
+ * around on the queue, we allocate a small notifier that is put on the
+ * socket's notifier_list. Notifications are delivered to the application
+ * through control messages.
+ */
+struct rds_notifier {
+        struct list_head        n_list;
+        uint64_t                n_user_token;
+        int                     n_status;
+};
+
+/**
+ * struct rds_transport -  transport specific behavioural hooks
+ *
+ * @xmit: .xmit is called by rds_send_xmit() to tell the transport to send
+ *        part of a message.  The caller serializes on the send_sem so this
+ *        doesn't need to be reentrant for a given conn.  The header must be
+ *        sent before the data payload.  .xmit must be prepared to send a
+ *        message with no data payload.  .xmit should return the number of
+ *        bytes that were sent down the connection, including header bytes.
+ *        Returning 0 tells the caller that it doesn't need to perform any
+ *        additional work now.  This is usually the case when the transport has
+ *        filled the sending queue for its connection and will handle
+ *        triggering the rds thread to continue the send when space becomes
+ *        available.  Returning -EAGAIN tells the caller to retry the send
+ *        immediately.  Returning -ENOMEM tells the caller to retry the send at
+ *        some point in the future.
+ *
+ * @conn_shutdown: conn_shutdown stops traffic on the given connection.  Once
+ *                 it returns the connection can not call rds_recv_incoming().
+ *                 This will only be called once after conn_connect returns
+ *                 non-zero success and will The caller serializes this with
+ *                 the send and connecting paths (xmit_* and conn_*).  The
+ *                 transport is responsible for other serialization, including
+ *                 rds_recv_incoming().  This is called in process context but
+ *                 should try hard not to block.
+ *
+ * @xmit_cong_map: This asks the transport to send the local bitmap down the
+ *                 given connection.  XXX get a better story about the bitmap
+ *                 flag and header.
+ */
+
+struct rds_transport {
+        char                    t_name[TRANSNAMSIZ];
+        struct list_head        t_item;
+        struct module           *t_owner;
+        unsigned int            t_prefer_loopback:1;
+
+        int (*laddr_check)(__be32 addr);
+        int (*conn_alloc)(struct rds_connection *conn, gfp_t gfp);
+        void (*conn_free)(void *data);
+        int (*conn_connect)(struct rds_connection *conn);
+        void (*conn_shutdown)(struct rds_connection *conn);
+        void (*xmit_prepare)(struct rds_connection *conn);
+        void (*xmit_complete)(struct rds_connection *conn);
+        int (*xmit)(struct rds_connection *conn, struct rds_message *rm,
+                    unsigned int hdr_off, unsigned int sg, unsigned int off);
+        int (*xmit_cong_map)(struct rds_connection *conn,
+                             struct rds_cong_map *map, unsigned long offset);
+        int (*xmit_rdma)(struct rds_connection *conn, struct rds_rdma_op *op);
+        int (*recv)(struct rds_connection *conn);
+        int (*inc_copy_to_user)(struct rds_incoming *inc, struct iovec *iov,
+                                size_t size);
+        void (*inc_purge)(struct rds_incoming *inc);
+        void (*inc_free)(struct rds_incoming *inc);
+
+        int (*cm_handle_connect)(struct rdma_cm_id *cm_id,
+                                 struct rdma_cm_event *event);
+        int (*cm_initiate_connect)(struct rdma_cm_id *cm_id);
+        void (*cm_connect_complete)(struct rds_connection *conn,
+                                    struct rdma_cm_event *event);
+
+        unsigned int (*stats_info_copy)(struct rds_info_iterator *iter,
+                                        unsigned int avail);
+        void (*exit)(void);
+        void *(*get_mr)(struct scatterlist *sg, unsigned long nr_sg,
+                        struct rds_sock *rs, u32 *key_ret);
+        void (*sync_mr)(void *trans_private, int direction);
+        void (*free_mr)(void *trans_private, int invalidate);
+        void (*flush_mrs)(void);
+};
+
+struct rds_sock {
+        struct sock             rs_sk;
+
+        u64                     rs_user_addr;
+        u64                     rs_user_bytes;
+
+        /*
+         * bound_addr used for both incoming and outgoing, no INADDR_ANY
+         * support.
+         */
+        struct rb_node          rs_bound_node;
+        __be32                  rs_bound_addr;
+        __be32                  rs_conn_addr;
+        __be16                  rs_bound_port;
+        __be16                  rs_conn_port;
+
+        /*
+         * This is only used to communicate the transport between bind and
+         * initiating connections.  All other trans use is referenced through
+         * the connection.
+         */
+        struct rds_transport    *rs_transport;
+
+        /*
+         * rds_sendmsg caches the conn it used the last time around.
+         * This helps avoid costly lookups.
+         */
+        struct rds_connection   *rs_conn;
+
+        /* flag indicating we were congested or not */
+        int                     rs_congested;
+
+        /* rs_lock protects all these adjacent members before the newline */
+        spinlock_t              rs_lock;
+        struct list_head        rs_send_queue;
+        u32                     rs_snd_bytes;
+        int                     rs_rcv_bytes;
+        struct list_head        rs_notify_queue;        /* currently used for failed RDMAs */
+
+        /* Congestion wake_up. If rs_cong_monitor is set, we use cong_mask
+         * to decide whether the application should be woken up.
+         * If not set, we use rs_cong_track to find out whether a cong map
+         * update arrived.
+         */
+        uint64_t                rs_cong_mask;
+        uint64_t                rs_cong_notify;
+        struct list_head        rs_cong_list;
+        unsigned long           rs_cong_track;
+
+        /*
+         * rs_recv_lock protects the receive queue, and is
+         * used to serialize with rds_release.
+         */
+        rwlock_t                rs_recv_lock;
+        struct list_head        rs_recv_queue;
+
+        /* just for stats reporting */
+        struct list_head        rs_item;
+
+        /* these have their own lock */
+        spinlock_t              rs_rdma_lock;
+        struct rb_root          rs_rdma_keys;
+
+        /* Socket options - in case there will be more */
+        unsigned char           rs_recverr,
+                                rs_cong_monitor;
+};
+
+static inline struct rds_sock *rds_sk_to_rs(const struct sock *sk)
+{
+        return container_of(sk, struct rds_sock, rs_sk);
+}
+static inline struct sock *rds_rs_to_sk(struct rds_sock *rs)
+{
+        return &rs->rs_sk;
+}
+
+/*
+ * The stack assigns sk_sndbuf and sk_rcvbuf to twice the specified value
+ * to account for overhead.  We don't account for overhead, we just apply
+ * the number of payload bytes to the specified value.
+ */
+static inline int rds_sk_sndbuf(struct rds_sock *rs)
+{
+        return rds_rs_to_sk(rs)->sk_sndbuf / 2;
+}
+static inline int rds_sk_rcvbuf(struct rds_sock *rs)
+{
+        return rds_rs_to_sk(rs)->sk_rcvbuf / 2;
+}
+
+struct rds_statistics {
+        uint64_t        s_conn_reset;
+        uint64_t        s_recv_drop_bad_checksum;
+        uint64_t        s_recv_drop_old_seq;
+        uint64_t        s_recv_drop_no_sock;
+        uint64_t        s_recv_drop_dead_sock;
+        uint64_t        s_recv_deliver_raced;
+        uint64_t        s_recv_delivered;
+        uint64_t        s_recv_queued;
+        uint64_t        s_recv_immediate_retry;
+        uint64_t        s_recv_delayed_retry;
+        uint64_t        s_recv_ack_required;
+        uint64_t        s_recv_rdma_bytes;
+        uint64_t        s_recv_ping;
+        uint64_t        s_send_queue_empty;
+        uint64_t        s_send_queue_full;
+        uint64_t        s_send_sem_contention;
+        uint64_t        s_send_sem_queue_raced;
+        uint64_t        s_send_immediate_retry;
+        uint64_t        s_send_delayed_retry;
+        uint64_t        s_send_drop_acked;
+        uint64_t        s_send_ack_required;
+        uint64_t        s_send_queued;
+        uint64_t        s_send_rdma;
+        uint64_t        s_send_rdma_bytes;
+        uint64_t        s_send_pong;
+        uint64_t        s_page_remainder_hit;
+        uint64_t        s_page_remainder_miss;
+        uint64_t        s_copy_to_user;
+        uint64_t        s_copy_from_user;
+        uint64_t        s_cong_update_queued;
+        uint64_t        s_cong_update_received;
+        uint64_t        s_cong_send_error;
+        uint64_t        s_cong_send_blocked;
+};
+
+/* af_rds.c */
+void rds_sock_addref(struct rds_sock *rs);
+void rds_sock_put(struct rds_sock *rs);
+void rds_wake_sk_sleep(struct rds_sock *rs);
+static inline void __rds_wake_sk_sleep(struct sock *sk)
+{
+        wait_queue_head_t *waitq = sk->sk_sleep;
+
+        if (!sock_flag(sk, SOCK_DEAD) && waitq)
+                wake_up(waitq);
+}
+extern wait_queue_head_t rds_poll_waitq;
+
+
+/* bind.c */
+int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
+void rds_remove_bound(struct rds_sock *rs);
+struct rds_sock *rds_find_bound(__be32 addr, __be16 port);
+
+/* cong.c */
+int rds_cong_get_maps(struct rds_connection *conn);
+void rds_cong_add_conn(struct rds_connection *conn);
+void rds_cong_remove_conn(struct rds_connection *conn);
+void rds_cong_set_bit(struct rds_cong_map *map, __be16 port);
+void rds_cong_clear_bit(struct rds_cong_map *map, __be16 port);
+int rds_cong_wait(struct rds_cong_map *map, __be16 port, int nonblock, struct rds_sock *rs);
+void rds_cong_queue_updates(struct rds_cong_map *map);
+void rds_cong_map_updated(struct rds_cong_map *map, uint64_t);
+int rds_cong_updated_since(unsigned long *recent);
+void rds_cong_add_socket(struct rds_sock *);
+void rds_cong_remove_socket(struct rds_sock *);
+void rds_cong_exit(void);
+struct rds_message *rds_cong_update_alloc(struct rds_connection *conn);
+
+/* conn.c */
+int __init rds_conn_init(void);
+void rds_conn_exit(void);
+struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr,
+                                       struct rds_transport *trans, gfp_t gfp);
+struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr,
+                               struct rds_transport *trans, gfp_t gfp);
+void rds_conn_destroy(struct rds_connection *conn);
+void rds_conn_reset(struct rds_connection *conn);
+void rds_conn_drop(struct rds_connection *conn);
+void rds_for_each_conn_info(struct socket *sock, unsigned int len,
+                          struct rds_info_iterator *iter,
+                          struct rds_info_lengths *lens,
+                          int (*visitor)(struct rds_connection *, void *),
+                          size_t item_len);
+void __rds_conn_error(struct rds_connection *conn, const char *, ...)
+                                __attribute__ ((format (printf, 2, 3)));
+#define rds_conn_error(conn, fmt...) \
+        __rds_conn_error(conn, KERN_WARNING "RDS: " fmt)
+
+static inline int
+rds_conn_transition(struct rds_connection *conn, int old, int new)
+{
+        return atomic_cmpxchg(&conn->c_state, old, new) == old;
+}
+
+static inline int
+rds_conn_state(struct rds_connection *conn)
+{
+        return atomic_read(&conn->c_state);
+}
+
+static inline int
+rds_conn_up(struct rds_connection *conn)
+{
+        return atomic_read(&conn->c_state) == RDS_CONN_UP;
+}
+
+static inline int
+rds_conn_connecting(struct rds_connection *conn)
+{
+        return atomic_read(&conn->c_state) == RDS_CONN_CONNECTING;
+}
+
+/* message.c */
+struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
+struct rds_message *rds_message_copy_from_user(struct iovec *first_iov,
+                                               size_t total_len);
+struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len);
+void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
+                                 __be16 dport, u64 seq);
+int rds_message_add_extension(struct rds_header *hdr,
+                              unsigned int type, const void *data, unsigned int len);
+int rds_message_next_extension(struct rds_header *hdr,
+                               unsigned int *pos, void *buf, unsigned int *buflen);
+int rds_message_add_version_extension(struct rds_header *hdr, unsigned int version);
+int rds_message_get_version_extension(struct rds_header *hdr, unsigned int *version);
+int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset);
+int rds_message_inc_copy_to_user(struct rds_incoming *inc,
+                                 struct iovec *first_iov, size_t size);
+void rds_message_inc_purge(struct rds_incoming *inc);
+void rds_message_inc_free(struct rds_incoming *inc);
+void rds_message_addref(struct rds_message *rm);
+void rds_message_put(struct rds_message *rm);
+void rds_message_wait(struct rds_message *rm);
+void rds_message_unmapped(struct rds_message *rm);
+
+static inline void rds_message_make_checksum(struct rds_header *hdr)
+{
+        hdr->h_csum = 0;
+        hdr->h_csum = ip_fast_csum((void *) hdr, sizeof(*hdr) >> 2);
+}
+
+static inline int rds_message_verify_checksum(const struct rds_header *hdr)
+{
+        return !hdr->h_csum || ip_fast_csum((void *) hdr, sizeof(*hdr) >> 2) == 0;
+}
+
+
+/* page.c */
+int rds_page_remainder_alloc(struct scatterlist *scat, unsigned long bytes,
+                             gfp_t gfp);
+int rds_page_copy_user(struct page *page, unsigned long offset,
+                       void __user *ptr, unsigned long bytes,
+                       int to_user);
+#define rds_page_copy_to_user(page, offset, ptr, bytes) \
+        rds_page_copy_user(page, offset, ptr, bytes, 1)
+#define rds_page_copy_from_user(page, offset, ptr, bytes) \
+        rds_page_copy_user(page, offset, ptr, bytes, 0)
+void rds_page_exit(void);
+
+/* recv.c */
+void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
+                  __be32 saddr);
+void rds_inc_addref(struct rds_incoming *inc);
+void rds_inc_put(struct rds_incoming *inc);
+void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
+                       struct rds_incoming *inc, gfp_t gfp, enum km_type km);
+int rds_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
+                size_t size, int msg_flags);
+void rds_clear_recv_queue(struct rds_sock *rs);
+int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msg);
+void rds_inc_info_copy(struct rds_incoming *inc,
+                       struct rds_info_iterator *iter,
+                       __be32 saddr, __be32 daddr, int flip);
+
+/* send.c */
+int rds_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
+                size_t payload_len);
+void rds_send_reset(struct rds_connection *conn);
+int rds_send_xmit(struct rds_connection *conn);
+struct sockaddr_in;
+void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest);
+typedef int (*is_acked_func)(struct rds_message *rm, uint64_t ack);
+void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
+                         is_acked_func is_acked);
+int rds_send_acked_before(struct rds_connection *conn, u64 seq);
+void rds_send_remove_from_sock(struct list_head *messages, int status);
+int rds_send_pong(struct rds_connection *conn, __be16 dport);
+struct rds_message *rds_send_get_message(struct rds_connection *,
+                                         struct rds_rdma_op *);
+
+/* rdma.c */
+void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force);
+
+/* stats.c */
+DECLARE_PER_CPU(struct rds_statistics, rds_stats);
+#define rds_stats_inc_which(which, member) do {         \
+        per_cpu(which, get_cpu()).member++;             \
+        put_cpu();                                      \
+} while (0)
+#define rds_stats_inc(member) rds_stats_inc_which(rds_stats, member)
+#define rds_stats_add_which(which, member, count) do {          \
+        per_cpu(which, get_cpu()).member += count;      \
+        put_cpu();                                      \
+} while (0)
+#define rds_stats_add(member, count) rds_stats_add_which(rds_stats, member, count)
+int __init rds_stats_init(void);
+void rds_stats_exit(void);
+void rds_stats_info_copy(struct rds_info_iterator *iter,
+                         uint64_t *values, char **names, size_t nr);
+
+/* sysctl.c */
+int __init rds_sysctl_init(void);
+void rds_sysctl_exit(void);
+extern unsigned long rds_sysctl_sndbuf_min;
+extern unsigned long rds_sysctl_sndbuf_default;
+extern unsigned long rds_sysctl_sndbuf_max;
+extern unsigned long rds_sysctl_reconnect_min_jiffies;
+extern unsigned long rds_sysctl_reconnect_max_jiffies;
+extern unsigned int  rds_sysctl_max_unacked_packets;
+extern unsigned int  rds_sysctl_max_unacked_bytes;
+extern unsigned int  rds_sysctl_ping_enable;
+extern unsigned long rds_sysctl_trace_flags;
+extern unsigned int  rds_sysctl_trace_level;
+
+/* threads.c */
+int __init rds_threads_init(void);
+void rds_threads_exit(void);
+extern struct workqueue_struct *rds_wq;
+void rds_connect_worker(struct work_struct *);
+void rds_shutdown_worker(struct work_struct *);
+void rds_send_worker(struct work_struct *);
+void rds_recv_worker(struct work_struct *);
+void rds_connect_complete(struct rds_connection *conn);
+
+/* transport.c */
+int rds_trans_register(struct rds_transport *trans);
+void rds_trans_unregister(struct rds_transport *trans);
+struct rds_transport *rds_trans_get_preferred(__be32 addr);
+unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
+                                       unsigned int avail);
+int __init rds_trans_init(void);
+void rds_trans_exit(void);
+
+#endif