tcp_internal.h

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/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * Copyright (C) 2005 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef R2CLUSTER_TCP_INTERNAL_H
#define R2CLUSTER_TCP_INTERNAL_H

#define R2NET_MSG_MAGIC           ((u16)0xfa55)
#define R2NET_MSG_STATUS_MAGIC    ((u16)0xfa56)
#define R2NET_MSG_KEEP_REQ_MAGIC  ((u16)0xfa57)
#define R2NET_MSG_KEEP_RESP_MAGIC ((u16)0xfa58)
/*
 * "data magic" is a long version of "status magic" where the message
 * payload actually contains data to be passed in reply to certain messages
 */
#define R2NET_MSG_DATA_MAGIC      ((u16)0xfa59)

/* we're delaying our quorum decision so that heartbeat will have timed
 * out truly dead nodes by the time we come around to making decisions
 * on their number */
#define R2NET_QUORUM_DELAY_MS   \
        ((r2hb_dead_threshold + 2) * R2HB_REGION_TIMEOUT_MS)

/*
 * This version number represents quite a lot, unfortunately.  It not
 * only represents the raw network message protocol on the wire but also
 * locking semantics of the file system using the protocol.  It should
 * be somewhere else, I'm sure, but right now it isn't.
 *
 * With version 11, we separate out the filesystem locking portion.  The
 * filesystem now has a major.minor version it negotiates.  Version 11
 * introduces this negotiation to the r2dlm protocol, and as such the
 * version here in tcp_internal.h should not need to be bumped for
 * filesystem locking changes.
 *
 * New in version 11
 *  - Negotiation of filesystem locking in the dlm join.
 *
 * New in version 10:
 *  - Meta/data locks combined
 *
 * New in version 9:
 *  - All votes removed
 *
 * New in version 8:
 *  - Replace delete inode votes with a cluster lock
 *
 * New in version 7:
 *  - DLM join domain includes the live nodemap
 *
 * New in version 6:
 *  - DLM lockres remote refcount fixes.
 *
 * New in version 5:
 *  - Network timeout checking protocol
 *
 * New in version 4:
 *  - Remove i_generation from lock names for better stat performance.
 *
 * New in version 3:
 *  - Replace dentry votes with a cluster lock
 *
 * New in version 2:
 *  - full 64 bit i_size in the metadata lock lvbs
 *  - introduction of "rw" lock and pushing meta/data locking down
 */
#define R2NET_PROTOCOL_VERSION 11ULL
struct r2net_handshake {
    __be64  protocol_version;
    __be64  connector_id;
    __be32  r2hb_heartbeat_timeout_ms;
    __be32  r2net_idle_timeout_ms;
    __be32  r2net_keepalive_delay_ms;
    __be32  r2net_reconnect_delay_ms;
};

struct r2net_node {
    /* this is never called from int/bh */
    spinlock_t          nn_lock;

    /* set the moment an sc is allocated and a connect is started */
    struct r2net_sock_container *nn_sc;
    /* _valid is only set after the handshake passes and tx can happen */
    unsigned            nn_sc_valid:1;
    /* if this is set tx just returns it */
    int             nn_persistent_error;
    /* It is only set to 1 after the idle time out. */
    atomic_t            nn_timeout;

    /* threads waiting for an sc to arrive wait on the wq for generation
     * to increase.  it is increased when a connecting socket succeeds
     * or fails or when an accepted socket is attached. */
    wait_queue_head_t       nn_sc_wq;

    struct idr          nn_status_idr;
    struct list_head        nn_status_list;

    /* connects are attempted from when heartbeat comes up until either hb
     * goes down, the node is unconfigured, no connect attempts succeed
     * before R2NET_CONN_IDLE_DELAY, or a connect succeeds.  connect_work
     * is queued from set_nn_state both from hb up and from itself if a
     * connect attempt fails and so can be self-arming.  shutdown is
     * careful to first mark the nn such that no connects will be attempted
     * before canceling delayed connect work and flushing the queue. */
    struct delayed_work     nn_connect_work;
    unsigned long           nn_last_connect_attempt;

    /* this is queued as nodes come up and is canceled when a connection is
     * established.  this expiring gives up on the node and errors out
     * transmits */
    struct delayed_work     nn_connect_expired;

    /* after we give up on a socket we wait a while before deciding
     * that it is still heartbeating and that we should do some
     * quorum work */
    struct delayed_work     nn_still_up;
};

struct r2net_sock_container {
    struct kref     sc_kref;
    /* the next two are valid for the life time of the sc */
    struct socket       *sc_sock;
    struct r2nm_node    *sc_node;

    /* all of these sc work structs hold refs on the sc while they are
     * queued.  they should not be able to ref a freed sc.  the teardown
     * race is with r2net_wq destruction in r2net_stop_listening() */

    /* rx and connect work are generated from socket callbacks.  sc
     * shutdown removes the callbacks and then flushes the work queue */
    struct work_struct  sc_rx_work;
    struct work_struct  sc_connect_work;
    /* shutdown work is triggered in two ways.  the simple way is
     * for a code path calls ensure_shutdown which gets a lock, removes
     * the sc from the nn, and queues the work.  in this case the
     * work is single-shot.  the work is also queued from a sock
     * callback, though, and in this case the work will find the sc
     * still on the nn and will call ensure_shutdown itself.. this
     * ends up triggering the shutdown work again, though nothing
     * will be done in that second iteration.  so work queue teardown
     * has to be careful to remove the sc from the nn before waiting
     * on the work queue so that the shutdown work doesn't remove the
     * sc and rearm itself.
     */
    struct work_struct  sc_shutdown_work;

    struct timer_list   sc_idle_timeout;
    struct delayed_work sc_keepalive_work;

    unsigned        sc_handshake_ok:1;

    struct page     *sc_page;
    size_t          sc_page_off;

    /* original handlers for the sockets */
    void            (*sc_state_change)(struct sock *sk);
    void            (*sc_data_ready)(struct sock *sk, int bytes);

    u32         sc_msg_key;
    u16         sc_msg_type;

#ifdef CONFIG_DEBUG_FS
    struct list_head        sc_net_debug_item;
    ktime_t         sc_tv_timer;
    ktime_t         sc_tv_data_ready;
    ktime_t         sc_tv_advance_start;
    ktime_t         sc_tv_advance_stop;
    ktime_t         sc_tv_func_start;
    ktime_t         sc_tv_func_stop;
#endif
#ifdef CONFIG_RAMSTER_FS_STATS
    ktime_t         sc_tv_acquiry_total;
    ktime_t         sc_tv_send_total;
    ktime_t         sc_tv_status_total;
    u32         sc_send_count;
    u32         sc_recv_count;
    ktime_t         sc_tv_process_total;
#endif
    struct mutex        sc_send_lock;
};

struct r2net_msg_handler {
    struct rb_node      nh_node;
    u32         nh_max_len;
    u32         nh_msg_type;
    u32         nh_key;
    r2net_msg_handler_func  *nh_func;
    r2net_msg_handler_func  *nh_func_data;
    r2net_post_msg_handler_func
                *nh_post_func;
    struct kref     nh_kref;
    struct list_head    nh_unregister_item;
};

enum r2net_system_error {
    R2NET_ERR_NONE = 0,
    R2NET_ERR_NO_HNDLR,
    R2NET_ERR_OVERFLOW,
    R2NET_ERR_DIED,
    R2NET_ERR_MAX
};

struct r2net_status_wait {
    enum r2net_system_error ns_sys_status;
    s32         ns_status;
    int         ns_id;
    wait_queue_head_t   ns_wq;
    struct list_head    ns_node_item;
};

#ifdef CONFIG_DEBUG_FS
/* just for state dumps */
struct r2net_send_tracking {
    struct list_head        st_net_debug_item;
    struct task_struct      *st_task;
    struct r2net_sock_container *st_sc;
    u32             st_id;
    u32             st_msg_type;
    u32             st_msg_key;
    u8              st_node;
    ktime_t             st_sock_time;
    ktime_t             st_send_time;
    ktime_t             st_status_time;
};
#else
struct r2net_send_tracking {
    u32 dummy;
};
#endif  /* CONFIG_DEBUG_FS */

#endif /* R2CLUSTER_TCP_INTERNAL_H */