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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/crc32c.h>
 #include <linux/ctype.h>
 #include <linux/highmem.h>
 #include <linux/inet.h>
 #include <linux/kthread.h>
 #include <linux/net.h>
 #include <linux/nsproxy.h>
 #include <linux/sched/mm.h>
 #include <linux/slab.h>
 #include <linux/socket.h>
 #include <linux/string.h>
 #ifdef  CONFIG_BLOCK
 #include <linux/bio.h>
 #endif  /* CONFIG_BLOCK */
 #include <linux/dns_resolver.h>
 #include <net/tcp.h>
 
 #include <linux/ceph/ceph_features.h>
 #include <linux/ceph/libceph.h>
 #include <linux/ceph/messenger.h>
 #include <linux/ceph/decode.h>
 #include <linux/ceph/pagelist.h>
 #include <linux/export.h>
 
 /*
  * Ceph uses the messenger to exchange ceph_msg messages with other
  * hosts in the system.  The messenger provides ordered and reliable
  * delivery.  We tolerate TCP disconnects by reconnecting (with
  * exponential backoff) in the case of a fault (disconnection, bad
  * crc, protocol error).  Acks allow sent messages to be discarded by
  * the sender.
  */
 
 /*
  * We track the state of the socket on a given connection using
  * values defined below.  The transition to a new socket state is
  * handled by a function which verifies we aren't coming from an
  * unexpected state.
  *
  *      --------
  *      | NEW* |  transient initial state
  *      --------
  *          | con_sock_state_init()
  *          v
  *      ----------
  *      | CLOSED |  initialized, but no socket (and no
  *      ----------  TCP connection)
  *       ^      \
  *       |       \ con_sock_state_connecting()
  *       |        ----------------------
  *       |                              \
  *       + con_sock_state_closed()       \
  *       |+---------------------------    \
  *       | \                          \    \
  *       |  -----------                \    \
  *       |  | CLOSING |  socket event;  \    \
  *       |  -----------  await close     \    \
  *       |       ^                        \   |
  *       |       |                         \  |
  *       |       + con_sock_state_closing() \ |
  *       |      / \                         | |
  *       |     /   ---------------          | |
  *       |    /                   \         v v
  *       |   /                    --------------
  *       |  /    -----------------| CONNECTING |  socket created, TCP
  *       |  |   /                 --------------  connect initiated
  *       |  |   | con_sock_state_connected()
  *       |  |   v
  *      -------------
  *      | CONNECTED |  TCP connection established
  *      -------------
  *
  * State values for ceph_connection->sock_state; NEW is assumed to be 0.
  */
 
 #define CON_SOCK_STATE_NEW      0   /* -> CLOSED */
 #define CON_SOCK_STATE_CLOSED       1   /* -> CONNECTING */
 #define CON_SOCK_STATE_CONNECTING   2   /* -> CONNECTED or -> CLOSING */
 #define CON_SOCK_STATE_CONNECTED    3   /* -> CLOSING or -> CLOSED */
 #define CON_SOCK_STATE_CLOSING      4   /* -> CLOSED */
 
 static bool con_flag_valid(unsigned long con_flag)
 {
     switch (con_flag) {
     case CEPH_CON_F_LOSSYTX:
     case CEPH_CON_F_KEEPALIVE_PENDING:
     case CEPH_CON_F_WRITE_PENDING:
     case CEPH_CON_F_SOCK_CLOSED:
     case CEPH_CON_F_BACKOFF:
         return true;
     default:
         return false;
     }
 }
 
 void ceph_con_flag_clear(struct ceph_connection *con, unsigned long con_flag)
 {
     BUG_ON(!con_flag_valid(con_flag));
 
     clear_bit(con_flag, &con->flags);
 }
 
 void ceph_con_flag_set(struct ceph_connection *con, unsigned long con_flag)
 {
     BUG_ON(!con_flag_valid(con_flag));
 
     set_bit(con_flag, &con->flags);
 }
 
 bool ceph_con_flag_test(struct ceph_connection *con, unsigned long con_flag)
 {
     BUG_ON(!con_flag_valid(con_flag));
 
     return test_bit(con_flag, &con->flags);
 }
 
 bool ceph_con_flag_test_and_clear(struct ceph_connection *con,
                   unsigned long con_flag)
 {
     BUG_ON(!con_flag_valid(con_flag));
 
     return test_and_clear_bit(con_flag, &con->flags);
 }
 
 bool ceph_con_flag_test_and_set(struct ceph_connection *con,
                 unsigned long con_flag)
 {
     BUG_ON(!con_flag_valid(con_flag));
 
     return test_and_set_bit(con_flag, &con->flags);
 }
 
 /* Slab caches for frequently-allocated structures */
 
 static struct kmem_cache    *ceph_msg_cache;
 
 #ifdef CONFIG_LOCKDEP
 static struct lock_class_key socket_class;
 #endif
 
 static void queue_con(struct ceph_connection *con);
 static void cancel_con(struct ceph_connection *con);
 static void ceph_con_workfn(struct work_struct *);
 static void con_fault(struct ceph_connection *con);
 
 /*
  * Nicely render a sockaddr as a string.  An array of formatted
  * strings is used, to approximate reentrancy.
  */
 #define ADDR_STR_COUNT_LOG  5   /* log2(# address strings in array) */
 #define ADDR_STR_COUNT      (1 << ADDR_STR_COUNT_LOG)
 #define ADDR_STR_COUNT_MASK (ADDR_STR_COUNT - 1)
 #define MAX_ADDR_STR_LEN    64  /* 54 is enough */
 
 static char addr_str[ADDR_STR_COUNT][MAX_ADDR_STR_LEN];
 static atomic_t addr_str_seq = ATOMIC_INIT(0);
 
 struct page *ceph_zero_page;        /* used in certain error cases */
 
 const char *ceph_pr_addr(const struct ceph_entity_addr *addr)
 {
     int i;
     char *s;
     struct sockaddr_storage ss = addr->in_addr; /* align */
     struct sockaddr_in *in4 = (struct sockaddr_in *)&ss;
     struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&ss;
 
     i = atomic_inc_return(&addr_str_seq) & ADDR_STR_COUNT_MASK;
     s = addr_str[i];
 
     switch (ss.ss_family) {
     case AF_INET:
         snprintf(s, MAX_ADDR_STR_LEN, "(%d)%pI4:%hu",
              le32_to_cpu(addr->type), &in4->sin_addr,
              ntohs(in4->sin_port));
         break;
 
     case AF_INET6:
         snprintf(s, MAX_ADDR_STR_LEN, "(%d)[%pI6c]:%hu",
              le32_to_cpu(addr->type), &in6->sin6_addr,
              ntohs(in6->sin6_port));
         break;
 
     default:
         snprintf(s, MAX_ADDR_STR_LEN, "(unknown sockaddr family %hu)",
              ss.ss_family);
     }
 
     return s;
 }
 EXPORT_SYMBOL(ceph_pr_addr);
 
 void ceph_encode_my_addr(struct ceph_messenger *msgr)
 {
     if (!ceph_msgr2(from_msgr(msgr))) {
         memcpy(&msgr->my_enc_addr, &msgr->inst.addr,
                sizeof(msgr->my_enc_addr));
         ceph_encode_banner_addr(&msgr->my_enc_addr);
     }
 }
 
 /*
  * work queue for all reading and writing to/from the socket.
  */
 static struct workqueue_struct *ceph_msgr_wq;
 
 static int ceph_msgr_slab_init(void)
 {
     BUG_ON(ceph_msg_cache);
     ceph_msg_cache = KMEM_CACHE(ceph_msg, 0);
     if (!ceph_msg_cache)
         return -ENOMEM;
 
     return 0;
 }
 
 static void ceph_msgr_slab_exit(void)
 {
     BUG_ON(!ceph_msg_cache);
     kmem_cache_destroy(ceph_msg_cache);
     ceph_msg_cache = NULL;
 }
 
 static void _ceph_msgr_exit(void)
 {
     if (ceph_msgr_wq) {
         destroy_workqueue(ceph_msgr_wq);
         ceph_msgr_wq = NULL;
     }
 
     BUG_ON(!ceph_zero_page);
     put_page(ceph_zero_page);
     ceph_zero_page = NULL;
 
     ceph_msgr_slab_exit();
 }
 
 int __init ceph_msgr_init(void)
 {
     if (ceph_msgr_slab_init())
         return -ENOMEM;
 
     BUG_ON(ceph_zero_page);
     ceph_zero_page = ZERO_PAGE(0);
     get_page(ceph_zero_page);
 
     /*
      * The number of active work items is limited by the number of
      * connections, so leave @max_active at default.
      */
     ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_MEM_RECLAIM, 0);
     if (ceph_msgr_wq)
         return 0;
 
     pr_err("msgr_init failed to create workqueue\n");
     _ceph_msgr_exit();
 
     return -ENOMEM;
 }
 
 void ceph_msgr_exit(void)
 {
     BUG_ON(ceph_msgr_wq == NULL);
 
     _ceph_msgr_exit();
 }
 
 void ceph_msgr_flush(void)
 {
     flush_workqueue(ceph_msgr_wq);
 }
 EXPORT_SYMBOL(ceph_msgr_flush);
 
 /* Connection socket state transition functions */
 
 static void con_sock_state_init(struct ceph_connection *con)
 {
     int old_state;
 
     old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
     if (WARN_ON(old_state != CON_SOCK_STATE_NEW))
         printk("%s: unexpected old state %d\n", __func__, old_state);
     dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
          CON_SOCK_STATE_CLOSED);
 }
 
 static void con_sock_state_connecting(struct ceph_connection *con)
 {
     int old_state;
 
     old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTING);
     if (WARN_ON(old_state != CON_SOCK_STATE_CLOSED))
         printk("%s: unexpected old state %d\n", __func__, old_state);
     dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
          CON_SOCK_STATE_CONNECTING);
 }
 
 static void con_sock_state_connected(struct ceph_connection *con)
 {
     int old_state;
 
     old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CONNECTED);
     if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING))
         printk("%s: unexpected old state %d\n", __func__, old_state);
     dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
          CON_SOCK_STATE_CONNECTED);
 }
 
 static void con_sock_state_closing(struct ceph_connection *con)
 {
     int old_state;
 
     old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSING);
     if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTING &&
             old_state != CON_SOCK_STATE_CONNECTED &&
             old_state != CON_SOCK_STATE_CLOSING))
         printk("%s: unexpected old state %d\n", __func__, old_state);
     dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
          CON_SOCK_STATE_CLOSING);
 }
 
 static void con_sock_state_closed(struct ceph_connection *con)
 {
     int old_state;
 
     old_state = atomic_xchg(&con->sock_state, CON_SOCK_STATE_CLOSED);
     if (WARN_ON(old_state != CON_SOCK_STATE_CONNECTED &&
             old_state != CON_SOCK_STATE_CLOSING &&
             old_state != CON_SOCK_STATE_CONNECTING &&
             old_state != CON_SOCK_STATE_CLOSED))
         printk("%s: unexpected old state %d\n", __func__, old_state);
     dout("%s con %p sock %d -> %d\n", __func__, con, old_state,
          CON_SOCK_STATE_CLOSED);
 }
 
 /*
  * socket callback functions
  */
 
 /* data available on socket, or listen socket received a connect */
 static void ceph_sock_data_ready(struct sock *sk)
 {
     struct ceph_connection *con = sk->sk_user_data;
     if (atomic_read(&con->msgr->stopping)) {
         return;
     }
 
     if (sk->sk_state != TCP_CLOSE_WAIT) {
         dout("%s %p state = %d, queueing work\n", __func__,
              con, con->state);
         queue_con(con);
     }
 }
 
 /* socket has buffer space for writing */
 static void ceph_sock_write_space(struct sock *sk)
 {
     struct ceph_connection *con = sk->sk_user_data;
 
     /* only queue to workqueue if there is data we want to write,
      * and there is sufficient space in the socket buffer to accept
      * more data.  clear SOCK_NOSPACE so that ceph_sock_write_space()
      * doesn't get called again until try_write() fills the socket
      * buffer. See net/ipv4/tcp_input.c:tcp_check_space()
      * and net/core/stream.c:sk_stream_write_space().
      */
     if (ceph_con_flag_test(con, CEPH_CON_F_WRITE_PENDING)) {
         if (sk_stream_is_writeable(sk)) {
             dout("%s %p queueing write work\n", __func__, con);
             clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
             queue_con(con);
         }
     } else {
         dout("%s %p nothing to write\n", __func__, con);
     }
 }
 
 /* socket's state has changed */
 static void ceph_sock_state_change(struct sock *sk)
 {
     struct ceph_connection *con = sk->sk_user_data;
 
     dout("%s %p state = %d sk_state = %u\n", __func__,
          con, con->state, sk->sk_state);
 
     switch (sk->sk_state) {
     case TCP_CLOSE:
         dout("%s TCP_CLOSE\n", __func__);
         fallthrough;
     case TCP_CLOSE_WAIT:
         dout("%s TCP_CLOSE_WAIT\n", __func__);
         con_sock_state_closing(con);
         ceph_con_flag_set(con, CEPH_CON_F_SOCK_CLOSED);
         queue_con(con);
         break;
     case TCP_ESTABLISHED:
         dout("%s TCP_ESTABLISHED\n", __func__);
         con_sock_state_connected(con);
         queue_con(con);
         break;
     default:    /* Everything else is uninteresting */
         break;
     }
 }
 
 /*
  * set up socket callbacks
  */
 static void set_sock_callbacks(struct socket *sock,
                    struct ceph_connection *con)
 {
     struct sock *sk = sock->sk;
     sk->sk_user_data = con;
     sk->sk_data_ready = ceph_sock_data_ready;
     sk->sk_write_space = ceph_sock_write_space;
     sk->sk_state_change = ceph_sock_state_change;
 }
 
 
 /*
  * socket helpers
  */
 
 /*
  * initiate connection to a remote socket.
  */
 int ceph_tcp_connect(struct ceph_connection *con)
 {
     struct sockaddr_storage ss = con->peer_addr.in_addr; /* align */
     struct socket *sock;
     unsigned int noio_flag;
     int ret;
 
     dout("%s con %p peer_addr %s\n", __func__, con,
          ceph_pr_addr(&con->peer_addr));
     BUG_ON(con->sock);
 
     /* sock_create_kern() allocates with GFP_KERNEL */
     noio_flag = memalloc_noio_save();
     ret = sock_create_kern(read_pnet(&con->msgr->net), ss.ss_family,
                    SOCK_STREAM, IPPROTO_TCP, &sock);
     memalloc_noio_restore(noio_flag);
     if (ret)
         return ret;
     sock->sk->sk_allocation = GFP_NOFS;
 
 #ifdef CONFIG_LOCKDEP
     lockdep_set_class(&sock->sk->sk_lock, &socket_class);
 #endif
 
     set_sock_callbacks(sock, con);
 
     con_sock_state_connecting(con);
     ret = sock->ops->connect(sock, (struct sockaddr *)&ss, sizeof(ss),
                  O_NONBLOCK);
     if (ret == -EINPROGRESS) {
         dout("connect %s EINPROGRESS sk_state = %u\n",
              ceph_pr_addr(&con->peer_addr),
              sock->sk->sk_state);
     } else if (ret < 0) {
         pr_err("connect %s error %d\n",
                ceph_pr_addr(&con->peer_addr), ret);
         sock_release(sock);
         return ret;
     }
 
     if (ceph_test_opt(from_msgr(con->msgr), TCP_NODELAY))
         tcp_sock_set_nodelay(sock->sk);
 
     con->sock = sock;
     return 0;
 }
 
 /*
  * Shutdown/close the socket for the given connection.
  */
 int ceph_con_close_socket(struct ceph_connection *con)
 {
     int rc = 0;
 
     dout("%s con %p sock %p\n", __func__, con, con->sock);
     if (con->sock) {
         rc = con->sock->ops->shutdown(con->sock, SHUT_RDWR);
         sock_release(con->sock);
         con->sock = NULL;
     }
 
     /*
      * Forcibly clear the SOCK_CLOSED flag.  It gets set
      * independent of the connection mutex, and we could have
      * received a socket close event before we had the chance to
      * shut the socket down.
      */
     ceph_con_flag_clear(con, CEPH_CON_F_SOCK_CLOSED);
 
     con_sock_state_closed(con);
     return rc;
 }
 
 static void ceph_con_reset_protocol(struct ceph_connection *con)
 {
     dout("%s con %p\n", __func__, con);
 
     ceph_con_close_socket(con);
     if (con->in_msg) {
         WARN_ON(con->in_msg->con != con);
         ceph_msg_put(con->in_msg);
         con->in_msg = NULL;
     }
     if (con->out_msg) {
         WARN_ON(con->out_msg->con != con);
         ceph_msg_put(con->out_msg);
         con->out_msg = NULL;
     }
     if (con->bounce_page) {
         __free_page(con->bounce_page);
         con->bounce_page = NULL;
     }
 
     if (ceph_msgr2(from_msgr(con->msgr)))
         ceph_con_v2_reset_protocol(con);
     else
         ceph_con_v1_reset_protocol(con);
 }
 
 /*
  * Reset a connection.  Discard all incoming and outgoing messages
  * and clear *_seq state.
  */
 static void ceph_msg_remove(struct ceph_msg *msg)
 {
     list_del_init(&msg->list_head);
 
     ceph_msg_put(msg);
 }
 
 static void ceph_msg_remove_list(struct list_head *head)
 {
     while (!list_empty(head)) {
         struct ceph_msg *msg = list_first_entry(head, struct ceph_msg,
                             list_head);
         ceph_msg_remove(msg);
     }
 }
 
 void ceph_con_reset_session(struct ceph_connection *con)
 {
     dout("%s con %p\n", __func__, con);
 
     WARN_ON(con->in_msg);
     WARN_ON(con->out_msg);
     ceph_msg_remove_list(&con->out_queue);
     ceph_msg_remove_list(&con->out_sent);
     con->out_seq = 0;
     con->in_seq = 0;
     con->in_seq_acked = 0;
 
     if (ceph_msgr2(from_msgr(con->msgr)))
         ceph_con_v2_reset_session(con);
     else
         ceph_con_v1_reset_session(con);
 }
 
 /*
  * mark a peer down.  drop any open connections.
  */
 void ceph_con_close(struct ceph_connection *con)
 {
     mutex_lock(&con->mutex);
     dout("con_close %p peer %s\n", con, ceph_pr_addr(&con->peer_addr));
     con->state = CEPH_CON_S_CLOSED;
 
     ceph_con_flag_clear(con, CEPH_CON_F_LOSSYTX);  /* so we retry next
                               connect */
     ceph_con_flag_clear(con, CEPH_CON_F_KEEPALIVE_PENDING);
     ceph_con_flag_clear(con, CEPH_CON_F_WRITE_PENDING);
     ceph_con_flag_clear(con, CEPH_CON_F_BACKOFF);
 
     ceph_con_reset_protocol(con);
     ceph_con_reset_session(con);
     cancel_con(con);
     mutex_unlock(&con->mutex);
 }
 EXPORT_SYMBOL(ceph_con_close);
 
 /*
  * Reopen a closed connection, with a new peer address.
  */
 void ceph_con_open(struct ceph_connection *con,
            __u8 entity_type, __u64 entity_num,
            struct ceph_entity_addr *addr)
 {
     mutex_lock(&con->mutex);
     dout("con_open %p %s\n", con, ceph_pr_addr(addr));
 
     WARN_ON(con->state != CEPH_CON_S_CLOSED);
     con->state = CEPH_CON_S_PREOPEN;
 
     con->peer_name.type = (__u8) entity_type;
     con->peer_name.num = cpu_to_le64(entity_num);
 
     memcpy(&con->peer_addr, addr, sizeof(*addr));
     con->delay = 0;      /* reset backoff memory */
     mutex_unlock(&con->mutex);
     queue_con(con);
 }
 EXPORT_SYMBOL(ceph_con_open);
 
 /*
  * return true if this connection ever successfully opened
  */
 bool ceph_con_opened(struct ceph_connection *con)
 {
     if (ceph_msgr2(from_msgr(con->msgr)))
         return ceph_con_v2_opened(con);
 
     return ceph_con_v1_opened(con);
 }
 
 /*
  * initialize a new connection.
  */
 void ceph_con_init(struct ceph_connection *con, void *private,
     const struct ceph_connection_operations *ops,
     struct ceph_messenger *msgr)
 {
     dout("con_init %p\n", con);
     memset(con, 0, sizeof(*con));
     con->private = private;
     con->ops = ops;
     con->msgr = msgr;
 
     con_sock_state_init(con);
 
     mutex_init(&con->mutex);
     INIT_LIST_HEAD(&con->out_queue);
     INIT_LIST_HEAD(&con->out_sent);
     INIT_DELAYED_WORK(&con->work, ceph_con_workfn);
 
     con->state = CEPH_CON_S_CLOSED;
 }
 EXPORT_SYMBOL(ceph_con_init);
 
 /*
  * We maintain a global counter to order connection attempts.  Get
  * a unique seq greater than @gt.
  */
 u32 ceph_get_global_seq(struct ceph_messenger *msgr, u32 gt)
 {
     u32 ret;
 
     spin_lock(&msgr->global_seq_lock);
     if (msgr->global_seq < gt)
         msgr->global_seq = gt;
     ret = ++msgr->global_seq;
     spin_unlock(&msgr->global_seq_lock);
     return ret;
 }
 
 /*
  * Discard messages that have been acked by the server.
  */
 void ceph_con_discard_sent(struct ceph_connection *con, u64 ack_seq)
 {
     struct ceph_msg *msg;
     u64 seq;
 
     dout("%s con %p ack_seq %llu\n", __func__, con, ack_seq);
     while (!list_empty(&con->out_sent)) {
         msg = list_first_entry(&con->out_sent, struct ceph_msg,
                        list_head);
         WARN_ON(msg->needs_out_seq);
         seq = le64_to_cpu(msg->hdr.seq);
         if (seq > ack_seq)
             break;
 
         dout("%s con %p discarding msg %p seq %llu\n", __func__, con,
              msg, seq);
         ceph_msg_remove(msg);
     }
 }
 
 /*
  * Discard messages that have been requeued in con_fault(), up to
  * reconnect_seq.  This avoids gratuitously resending messages that
  * the server had received and handled prior to reconnect.
  */
 void ceph_con_discard_requeued(struct ceph_connection *con, u64 reconnect_seq)
 {
     struct ceph_msg *msg;
     u64 seq;
 
     dout("%s con %p reconnect_seq %llu\n", __func__, con, reconnect_seq);
     while (!list_empty(&con->out_queue)) {
         msg = list_first_entry(&con->out_queue, struct ceph_msg,
                        list_head);
         if (msg->needs_out_seq)
             break;
         seq = le64_to_cpu(msg->hdr.seq);
         if (seq > reconnect_seq)
             break;
 
         dout("%s con %p discarding msg %p seq %llu\n", __func__, con,
              msg, seq);
         ceph_msg_remove(msg);
     }
 }
 
 #ifdef CONFIG_BLOCK
 
 /*
  * For a bio data item, a piece is whatever remains of the next
  * entry in the current bio iovec, or the first entry in the next
  * bio in the list.
  */
 static void ceph_msg_data_bio_cursor_init(struct ceph_msg_data_cursor *cursor,
                     size_t length)
 {
     struct ceph_msg_data *data = cursor->data;
     struct ceph_bio_iter *it = &cursor->bio_iter;
 
     cursor->resid = min_t(size_t, length, data->bio_length);
     *it = data->bio_pos;
     if (cursor->resid < it->iter.bi_size)
         it->iter.bi_size = cursor->resid;
 
     BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
     cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
 }
 
 static struct page *ceph_msg_data_bio_next(struct ceph_msg_data_cursor *cursor,
                         size_t *page_offset,
                         size_t *length)
 {
     struct bio_vec bv = bio_iter_iovec(cursor->bio_iter.bio,
                        cursor->bio_iter.iter);
 
     *page_offset = bv.bv_offset;
     *length = bv.bv_len;
     return bv.bv_page;
 }
 
 static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
                     size_t bytes)
 {
     struct ceph_bio_iter *it = &cursor->bio_iter;
     struct page *page = bio_iter_page(it->bio, it->iter);
 
     BUG_ON(bytes > cursor->resid);
     BUG_ON(bytes > bio_iter_len(it->bio, it->iter));
     cursor->resid -= bytes;
     bio_advance_iter(it->bio, &it->iter, bytes);
 
     if (!cursor->resid) {
         BUG_ON(!cursor->last_piece);
         return false;   /* no more data */
     }
 
     if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done &&
                page == bio_iter_page(it->bio, it->iter)))
         return false;   /* more bytes to process in this segment */
 
     if (!it->iter.bi_size) {
         it->bio = it->bio->bi_next;
         it->iter = it->bio->bi_iter;
         if (cursor->resid < it->iter.bi_size)
             it->iter.bi_size = cursor->resid;
     }
 
     BUG_ON(cursor->last_piece);
     BUG_ON(cursor->resid < bio_iter_len(it->bio, it->iter));
     cursor->last_piece = cursor->resid == bio_iter_len(it->bio, it->iter);
     return true;
 }
 #endif /* CONFIG_BLOCK */
 
 static void ceph_msg_data_bvecs_cursor_init(struct ceph_msg_data_cursor *cursor,
                     size_t length)
 {
     struct ceph_msg_data *data = cursor->data;
     struct bio_vec *bvecs = data->bvec_pos.bvecs;
 
     cursor->resid = min_t(size_t, length, data->bvec_pos.iter.bi_size);
     cursor->bvec_iter = data->bvec_pos.iter;
     cursor->bvec_iter.bi_size = cursor->resid;
 
     BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
     cursor->last_piece =
         cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
 }
 
 static struct page *ceph_msg_data_bvecs_next(struct ceph_msg_data_cursor *cursor,
                         size_t *page_offset,
                         size_t *length)
 {
     struct bio_vec bv = bvec_iter_bvec(cursor->data->bvec_pos.bvecs,
                        cursor->bvec_iter);
 
     *page_offset = bv.bv_offset;
     *length = bv.bv_len;
     return bv.bv_page;
 }
 
 static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
                     size_t bytes)
 {
     struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
     struct page *page = bvec_iter_page(bvecs, cursor->bvec_iter);
 
     BUG_ON(bytes > cursor->resid);
     BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));
     cursor->resid -= bytes;
     bvec_iter_advance(bvecs, &cursor->bvec_iter, bytes);
 
     if (!cursor->resid) {
         BUG_ON(!cursor->last_piece);
         return false;   /* no more data */
     }
 
     if (!bytes || (cursor->bvec_iter.bi_bvec_done &&
                page == bvec_iter_page(bvecs, cursor->bvec_iter)))
         return false;   /* more bytes to process in this segment */
 
     BUG_ON(cursor->last_piece);
     BUG_ON(cursor->resid < bvec_iter_len(bvecs, cursor->bvec_iter));
     cursor->last_piece =
         cursor->resid == bvec_iter_len(bvecs, cursor->bvec_iter);
     return true;
 }
 
 /*
  * For a page array, a piece comes from the first page in the array
  * that has not already been fully consumed.
  */
 static void ceph_msg_data_pages_cursor_init(struct ceph_msg_data_cursor *cursor,
                     size_t length)
 {
     struct ceph_msg_data *data = cursor->data;
     int page_count;
 
     BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
 
     BUG_ON(!data->pages);
     BUG_ON(!data->length);
 
     cursor->resid = min(length, data->length);
     page_count = calc_pages_for(data->alignment, (u64)data->length);
     cursor->page_offset = data->alignment & ~PAGE_MASK;
     cursor->page_index = 0;
     BUG_ON(page_count > (int)USHRT_MAX);
     cursor->page_count = (unsigned short)page_count;
     BUG_ON(length > SIZE_MAX - cursor->page_offset);
     cursor->last_piece = cursor->page_offset + cursor->resid <= PAGE_SIZE;
 }
 
 static struct page *
 ceph_msg_data_pages_next(struct ceph_msg_data_cursor *cursor,
                     size_t *page_offset, size_t *length)
 {
     struct ceph_msg_data *data = cursor->data;
 
     BUG_ON(data->type != CEPH_MSG_DATA_PAGES);
 
     BUG_ON(cursor->page_index >= cursor->page_count);
     BUG_ON(cursor->page_offset >= PAGE_SIZE);
 
     *page_offset = cursor->page_offset;
     if (cursor->last_piece)
         *length = cursor->resid;
     else
         *length = PAGE_SIZE - *page_offset;
 
     return data->pages[cursor->page_index];
 }
 
 static bool ceph_msg_data_pages_advance(struct ceph_msg_data_cursor *cursor,
                         size_t bytes)
 {
     BUG_ON(cursor->data->type != CEPH_MSG_DATA_PAGES);
 
     BUG_ON(cursor->page_offset + bytes > PAGE_SIZE);
 
     /* Advance the cursor page offset */
 
     cursor->resid -= bytes;
     cursor->page_offset = (cursor->page_offset + bytes) & ~PAGE_MASK;
     if (!bytes || cursor->page_offset)
         return false;   /* more bytes to process in the current page */
 
     if (!cursor->resid)
         return false;   /* no more data */
 
     /* Move on to the next page; offset is already at 0 */
 
     BUG_ON(cursor->page_index >= cursor->page_count);
     cursor->page_index++;
     cursor->last_piece = cursor->resid <= PAGE_SIZE;
 
     return true;
 }
 
 /*
  * For a pagelist, a piece is whatever remains to be consumed in the
  * first page in the list, or the front of the next page.
  */
 static void
 ceph_msg_data_pagelist_cursor_init(struct ceph_msg_data_cursor *cursor,
                     size_t length)
 {
     struct ceph_msg_data *data = cursor->data;
     struct ceph_pagelist *pagelist;
     struct page *page;
 
     BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
 
     pagelist = data->pagelist;
     BUG_ON(!pagelist);
 
     if (!length)
         return;     /* pagelist can be assigned but empty */
 
     BUG_ON(list_empty(&pagelist->head));
     page = list_first_entry(&pagelist->head, struct page, lru);
 
     cursor->resid = min(length, pagelist->length);
     cursor->page = page;
     cursor->offset = 0;
     cursor->last_piece = cursor->resid <= PAGE_SIZE;
 }
 
 static struct page *
 ceph_msg_data_pagelist_next(struct ceph_msg_data_cursor *cursor,
                 size_t *page_offset, size_t *length)
 {
     struct ceph_msg_data *data = cursor->data;
     struct ceph_pagelist *pagelist;
 
     BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
 
     pagelist = data->pagelist;
     BUG_ON(!pagelist);
 
     BUG_ON(!cursor->page);
     BUG_ON(cursor->offset + cursor->resid != pagelist->length);
 
     /* offset of first page in pagelist is always 0 */
     *page_offset = cursor->offset & ~PAGE_MASK;
     if (cursor->last_piece)
         *length = cursor->resid;
     else
         *length = PAGE_SIZE - *page_offset;
 
     return cursor->page;
 }
 
 static bool ceph_msg_data_pagelist_advance(struct ceph_msg_data_cursor *cursor,
                         size_t bytes)
 {
     struct ceph_msg_data *data = cursor->data;
     struct ceph_pagelist *pagelist;
 
     BUG_ON(data->type != CEPH_MSG_DATA_PAGELIST);
 
     pagelist = data->pagelist;
     BUG_ON(!pagelist);
 
     BUG_ON(cursor->offset + cursor->resid != pagelist->length);
     BUG_ON((cursor->offset & ~PAGE_MASK) + bytes > PAGE_SIZE);
 
     /* Advance the cursor offset */
 
     cursor->resid -= bytes;
     cursor->offset += bytes;
     /* offset of first page in pagelist is always 0 */
     if (!bytes || cursor->offset & ~PAGE_MASK)
         return false;   /* more bytes to process in the current page */
 
     if (!cursor->resid)
         return false;   /* no more data */
 
     /* Move on to the next page */
 
     BUG_ON(list_is_last(&cursor->page->lru, &pagelist->head));
     cursor->page = list_next_entry(cursor->page, lru);
     cursor->last_piece = cursor->resid <= PAGE_SIZE;
 
     return true;
 }
 
 /*
  * Message data is handled (sent or received) in pieces, where each
  * piece resides on a single page.  The network layer might not
  * consume an entire piece at once.  A data item's cursor keeps
  * track of which piece is next to process and how much remains to
  * be processed in that piece.  It also tracks whether the current
  * piece is the last one in the data item.
  */
 static void __ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor)
 {
     size_t length = cursor->total_resid;
 
     switch (cursor->data->type) {
     case CEPH_MSG_DATA_PAGELIST:
         ceph_msg_data_pagelist_cursor_init(cursor, length);
         break;
     case CEPH_MSG_DATA_PAGES:
         ceph_msg_data_pages_cursor_init(cursor, length);
         break;
 #ifdef CONFIG_BLOCK
     case CEPH_MSG_DATA_BIO:
         ceph_msg_data_bio_cursor_init(cursor, length);
         break;
 #endif /* CONFIG_BLOCK */
     case CEPH_MSG_DATA_BVECS:
         ceph_msg_data_bvecs_cursor_init(cursor, length);
         break;
     case CEPH_MSG_DATA_NONE:
     default:
         /* BUG(); */
         break;
     }
     cursor->need_crc = true;
 }
 
 void ceph_msg_data_cursor_init(struct ceph_msg_data_cursor *cursor,
                    struct ceph_msg *msg, size_t length)
 {
     BUG_ON(!length);
     BUG_ON(length > msg->data_length);
     BUG_ON(!msg->num_data_items);
 
     cursor->total_resid = length;
     cursor->data = msg->data;
 
     __ceph_msg_data_cursor_init(cursor);
 }
 
 /*
  * Return the page containing the next piece to process for a given
  * data item, and supply the page offset and length of that piece.
  * Indicate whether this is the last piece in this data item.
  */
 struct page *ceph_msg_data_next(struct ceph_msg_data_cursor *cursor,
                 size_t *page_offset, size_t *length,
                 bool *last_piece)
 {
     struct page *page;
 
     switch (cursor->data->type) {
     case CEPH_MSG_DATA_PAGELIST:
         page = ceph_msg_data_pagelist_next(cursor, page_offset, length);
         break;
     case CEPH_MSG_DATA_PAGES:
         page = ceph_msg_data_pages_next(cursor, page_offset, length);
         break;
 #ifdef CONFIG_BLOCK
     case CEPH_MSG_DATA_BIO:
         page = ceph_msg_data_bio_next(cursor, page_offset, length);
         break;
 #endif /* CONFIG_BLOCK */
     case CEPH_MSG_DATA_BVECS:
         page = ceph_msg_data_bvecs_next(cursor, page_offset, length);
         break;
     case CEPH_MSG_DATA_NONE:
     default:
         page = NULL;
         break;
     }
 
     BUG_ON(!page);
     BUG_ON(*page_offset + *length > PAGE_SIZE);
     BUG_ON(!*length);
     BUG_ON(*length > cursor->resid);
     if (last_piece)
         *last_piece = cursor->last_piece;
 
     return page;
 }
 
 /*
  * Returns true if the result moves the cursor on to the next piece
  * of the data item.
  */
 void ceph_msg_data_advance(struct ceph_msg_data_cursor *cursor, size_t bytes)
 {
     bool new_piece;
 
     BUG_ON(bytes > cursor->resid);
     switch (cursor->data->type) {
     case CEPH_MSG_DATA_PAGELIST:
         new_piece = ceph_msg_data_pagelist_advance(cursor, bytes);
         break;
     case CEPH_MSG_DATA_PAGES:
         new_piece = ceph_msg_data_pages_advance(cursor, bytes);
         break;
 #ifdef CONFIG_BLOCK
     case CEPH_MSG_DATA_BIO:
         new_piece = ceph_msg_data_bio_advance(cursor, bytes);
         break;
 #endif /* CONFIG_BLOCK */
     case CEPH_MSG_DATA_BVECS:
         new_piece = ceph_msg_data_bvecs_advance(cursor, bytes);
         break;
     case CEPH_MSG_DATA_NONE:
     default:
         BUG();
         break;
     }
     cursor->total_resid -= bytes;
 
     if (!cursor->resid && cursor->total_resid) {
         WARN_ON(!cursor->last_piece);
         cursor->data++;
         __ceph_msg_data_cursor_init(cursor);
         new_piece = true;
     }
     cursor->need_crc = new_piece;
 }
 
 u32 ceph_crc32c_page(u32 crc, struct page *page, unsigned int page_offset,
              unsigned int length)
 {
     char *kaddr;
 
     kaddr = kmap(page);
     BUG_ON(kaddr == NULL);
     crc = crc32c(crc, kaddr + page_offset, length);
     kunmap(page);
 
     return crc;
 }
 
 bool ceph_addr_is_blank(const struct ceph_entity_addr *addr)
 {
     struct sockaddr_storage ss = addr->in_addr; /* align */
     struct in_addr *addr4 = &((struct sockaddr_in *)&ss)->sin_addr;
     struct in6_addr *addr6 = &((struct sockaddr_in6 *)&ss)->sin6_addr;
 
     switch (ss.ss_family) {
     case AF_INET:
         return addr4->s_addr == htonl(INADDR_ANY);
     case AF_INET6:
         return ipv6_addr_any(addr6);
     default:
         return true;
     }
 }
 
 int ceph_addr_port(const struct ceph_entity_addr *addr)
 {
     switch (get_unaligned(&addr->in_addr.ss_family)) {
     case AF_INET:
         return ntohs(get_unaligned(&((struct sockaddr_in *)&addr->in_addr)->sin_port));
     case AF_INET6:
         return ntohs(get_unaligned(&((struct sockaddr_in6 *)&addr->in_addr)->sin6_port));
     }
     return 0;
 }
 
 void ceph_addr_set_port(struct ceph_entity_addr *addr, int p)
 {
     switch (get_unaligned(&addr->in_addr.ss_family)) {
     case AF_INET:
         put_unaligned(htons(p), &((struct sockaddr_in *)&addr->in_addr)->sin_port);
         break;
     case AF_INET6:
         put_unaligned(htons(p), &((struct sockaddr_in6 *)&addr->in_addr)->sin6_port);
         break;
     }
 }
 
 /*
  * Unlike other *_pton function semantics, zero indicates success.
  */
 static int ceph_pton(const char *str, size_t len, struct ceph_entity_addr *addr,
         char delim, const char **ipend)
 {
     memset(&addr->in_addr, 0, sizeof(addr->in_addr));
 
     if (in4_pton(str, len, (u8 *)&((struct sockaddr_in *)&addr->in_addr)->sin_addr.s_addr, delim, ipend)) {
         put_unaligned(AF_INET, &addr->in_addr.ss_family);
         return 0;
     }
 
     if (in6_pton(str, len, (u8 *)&((struct sockaddr_in6 *)&addr->in_addr)->sin6_addr.s6_addr, delim, ipend)) {
         put_unaligned(AF_INET6, &addr->in_addr.ss_family);
         return 0;
     }
 
     return -EINVAL;
 }
 
 /*
  * Extract hostname string and resolve using kernel DNS facility.
  */
 #ifdef CONFIG_CEPH_LIB_USE_DNS_RESOLVER
 static int ceph_dns_resolve_name(const char *name, size_t namelen,
         struct ceph_entity_addr *addr, char delim, const char **ipend)
 {
     const char *end, *delim_p;
     char *colon_p, *ip_addr = NULL;
     int ip_len, ret;
 
     /*
      * The end of the hostname occurs immediately preceding the delimiter or
      * the port marker (':') where the delimiter takes precedence.
      */
     delim_p = memchr(name, delim, namelen);
     colon_p = memchr(name, ':', namelen);
 
     if (delim_p && colon_p)
         end = delim_p < colon_p ? delim_p : colon_p;
     else if (!delim_p && colon_p)
         end = colon_p;
     else {
         end = delim_p;
         if (!end) /* case: hostname:/ */
             end = name + namelen;
     }
 
     if (end <= name)
         return -EINVAL;
 
     /* do dns_resolve upcall */
     ip_len = dns_query(current->nsproxy->net_ns,
                NULL, name, end - name, NULL, &ip_addr, NULL, false);
     if (ip_len > 0)
         ret = ceph_pton(ip_addr, ip_len, addr, -1, NULL);
     else
         ret = -ESRCH;
 
     kfree(ip_addr);
 
     *ipend = end;
 
     pr_info("resolve '%.*s' (ret=%d): %s\n", (int)(end - name), name,
             ret, ret ? "failed" : ceph_pr_addr(addr));
 
     return ret;
 }
 #else
 static inline int ceph_dns_resolve_name(const char *name, size_t namelen,
         struct ceph_entity_addr *addr, char delim, const char **ipend)
 {
     return -EINVAL;
 }
 #endif
 
 /*
  * Parse a server name (IP or hostname). If a valid IP address is not found
  * then try to extract a hostname to resolve using userspace DNS upcall.
  */
 static int ceph_parse_server_name(const char *name, size_t namelen,
         struct ceph_entity_addr *addr, char delim, const char **ipend)
 {
     int ret;
 
     ret = ceph_pton(name, namelen, addr, delim, ipend);
     if (ret)
         ret = ceph_dns_resolve_name(name, namelen, addr, delim, ipend);
 
     return ret;
 }
 
 /*
  * Parse an ip[:port] list into an addr array.  Use the default
  * monitor port if a port isn't specified.
  */
 int ceph_parse_ips(const char *c, const char *end,
            struct ceph_entity_addr *addr,
            int max_count, int *count, char delim)
 {
     int i, ret = -EINVAL;
     const char *p = c;
 
     dout("parse_ips on '%.*s'\n", (int)(end-c), c);
     for (i = 0; i < max_count; i++) {
         char cur_delim = delim;
         const char *ipend;
         int port;
 
         if (*p == '[') {
             cur_delim = ']';
             p++;
         }
 
         ret = ceph_parse_server_name(p, end - p, &addr[i], cur_delim,
                          &ipend);
         if (ret)
             goto bad;
         ret = -EINVAL;
 
         p = ipend;
 
         if (cur_delim == ']') {
             if (*p != ']') {
                 dout("missing matching ']'\n");
                 goto bad;
             }
             p++;
         }
 
         /* port? */
         if (p < end && *p == ':') {
             port = 0;
             p++;
             while (p < end && *p >= '0' && *p <= '9') {
                 port = (port * 10) + (*p - '0');
                 p++;
             }
             if (port == 0)
                 port = CEPH_MON_PORT;
             else if (port > 65535)
                 goto bad;
         } else {
             port = CEPH_MON_PORT;
         }
 
         ceph_addr_set_port(&addr[i], port);
         /*
          * We want the type to be set according to ms_mode
          * option, but options are normally parsed after mon
          * addresses.  Rather than complicating parsing, set
          * to LEGACY and override in build_initial_monmap()
          * for mon addresses and ceph_messenger_init() for
          * ip option.
          */
         addr[i].type = CEPH_ENTITY_ADDR_TYPE_LEGACY;
         addr[i].nonce = 0;
 
         dout("%s got %s\n", __func__, ceph_pr_addr(&addr[i]));
 
         if (p == end)
             break;
         if (*p != delim)
             goto bad;
         p++;
     }
 
     if (p != end)
         goto bad;
 
     if (count)
         *count = i + 1;
     return 0;
 
 bad:
     return ret;
 }
 
 /*
  * Process message.  This happens in the worker thread.  The callback should
  * be careful not to do anything that waits on other incoming messages or it
  * may deadlock.
  */
 void ceph_con_process_message(struct ceph_connection *con)
 {
     struct ceph_msg *msg = con->in_msg;
 
     BUG_ON(con->in_msg->con != con);
     con->in_msg = NULL;
 
     /* if first message, set peer_name */
     if (con->peer_name.type == 0)
         con->peer_name = msg->hdr.src;
 
     con->in_seq++;
     mutex_unlock(&con->mutex);
 
     dout("===== %p %llu from %s%lld %d=%s len %d+%d+%d (%u %u %u) =====\n",
          msg, le64_to_cpu(msg->hdr.seq),
          ENTITY_NAME(msg->hdr.src),
          le16_to_cpu(msg->hdr.type),
          ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
          le32_to_cpu(msg->hdr.front_len),
          le32_to_cpu(msg->hdr.middle_len),
          le32_to_cpu(msg->hdr.data_len),
          con->in_front_crc, con->in_middle_crc, con->in_data_crc);
     con->ops->dispatch(con, msg);
 
     mutex_lock(&con->mutex);
 }
 
 /*
  * Atomically queue work on a connection after the specified delay.
  * Bump @con reference to avoid races with connection teardown.
  * Returns 0 if work was queued, or an error code otherwise.
  */
 static int queue_con_delay(struct ceph_connection *con, unsigned long delay)
 {
     if (!con->ops->get(con)) {
         dout("%s %p ref count 0\n", __func__, con);
         return -ENOENT;
     }
 
     if (delay >= HZ)
         delay = round_jiffies_relative(delay);
 
     dout("%s %p %lu\n", __func__, con, delay);
     if (!queue_delayed_work(ceph_msgr_wq, &con->work, delay)) {
         dout("%s %p - already queued\n", __func__, con);
         con->ops->put(con);
         return -EBUSY;
     }
 
     return 0;
 }
 
 static void queue_con(struct ceph_connection *con)
 {
     (void) queue_con_delay(con, 0);
 }
 
 static void cancel_con(struct ceph_connection *con)
 {
     if (cancel_delayed_work(&con->work)) {
         dout("%s %p\n", __func__, con);
         con->ops->put(con);
     }
 }
 
 static bool con_sock_closed(struct ceph_connection *con)
 {
     if (!ceph_con_flag_test_and_clear(con, CEPH_CON_F_SOCK_CLOSED))
         return false;
 
 #define CASE(x)                             \
     case CEPH_CON_S_ ## x:                      \
         con->error_msg = "socket closed (con state " #x ")";    \
         break;
 
     switch (con->state) {
     CASE(CLOSED);
     CASE(PREOPEN);
     CASE(V1_BANNER);
     CASE(V1_CONNECT_MSG);
     CASE(V2_BANNER_PREFIX);
     CASE(V2_BANNER_PAYLOAD);
     CASE(V2_HELLO);
     CASE(V2_AUTH);
     CASE(V2_AUTH_SIGNATURE);
     CASE(V2_SESSION_CONNECT);
     CASE(V2_SESSION_RECONNECT);
     CASE(OPEN);
     CASE(STANDBY);
     default:
         BUG();
     }
 #undef CASE
 
     return true;
 }
 
 static bool con_backoff(struct ceph_connection *con)
 {
     int ret;
 
     if (!ceph_con_flag_test_and_clear(con, CEPH_CON_F_BACKOFF))
         return false;
 
     ret = queue_con_delay(con, con->delay);
     if (ret) {
         dout("%s: con %p FAILED to back off %lu\n", __func__,
             con, con->delay);
         BUG_ON(ret == -ENOENT);
         ceph_con_flag_set(con, CEPH_CON_F_BACKOFF);
     }
 
     return true;
 }
 
 /* Finish fault handling; con->mutex must *not* be held here */
 
 static void con_fault_finish(struct ceph_connection *con)
 {
     dout("%s %p\n", __func__, con);
 
     /*
      * in case we faulted due to authentication, invalidate our
      * current tickets so that we can get new ones.
      */
     if (con->v1.auth_retry) {
         dout("auth_retry %d, invalidating\n", con->v1.auth_retry);
         if (con->ops->invalidate_authorizer)
             con->ops->invalidate_authorizer(con);
         con->v1.auth_retry = 0;
     }
 
     if (con->ops->fault)
         con->ops->fault(con);
 }
 
 /*
  * Do some work on a connection.  Drop a connection ref when we're done.
  */
 static void ceph_con_workfn(struct work_struct *work)
 {
     struct ceph_connection *con = container_of(work, struct ceph_connection,
                            work.work);
     bool fault;
 
     mutex_lock(&con->mutex);
     while (true) {
         int ret;
 
         if ((fault = con_sock_closed(con))) {
             dout("%s: con %p SOCK_CLOSED\n", __func__, con);
             break;
         }
         if (con_backoff(con)) {
             dout("%s: con %p BACKOFF\n", __func__, con);
             break;
         }
         if (con->state == CEPH_CON_S_STANDBY) {
             dout("%s: con %p STANDBY\n", __func__, con);
             break;
         }
         if (con->state == CEPH_CON_S_CLOSED) {
             dout("%s: con %p CLOSED\n", __func__, con);
             BUG_ON(con->sock);
             break;
         }
         if (con->state == CEPH_CON_S_PREOPEN) {
             dout("%s: con %p PREOPEN\n", __func__, con);
             BUG_ON(con->sock);
         }
 
         if (ceph_msgr2(from_msgr(con->msgr)))
             ret = ceph_con_v2_try_read(con);
         else
             ret = ceph_con_v1_try_read(con);
         if (ret < 0) {
             if (ret == -EAGAIN)
                 continue;
             if (!con->error_msg)
                 con->error_msg = "socket error on read";
             fault = true;
             break;
         }
 
         if (ceph_msgr2(from_msgr(con->msgr)))
             ret = ceph_con_v2_try_write(con);
         else
             ret = ceph_con_v1_try_write(con);
         if (ret < 0) {
             if (ret == -EAGAIN)
                 continue;
             if (!con->error_msg)
                 con->error_msg = "socket error on write";
             fault = true;
         }
 
         break;  /* If we make it to here, we're done */
     }
     if (fault)
         con_fault(con);
     mutex_unlock(&con->mutex);
 
     if (fault)
         con_fault_finish(con);
 
     con->ops->put(con);
 }
 
 /*
  * Generic error/fault handler.  A retry mechanism is used with
  * exponential backoff
  */
 static void con_fault(struct ceph_connection *con)
 {
     dout("fault %p state %d to peer %s\n",
          con, con->state, ceph_pr_addr(&con->peer_addr));
 
     pr_warn("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
         ceph_pr_addr(&con->peer_addr), con->error_msg);
     con->error_msg = NULL;
 
     WARN_ON(con->state == CEPH_CON_S_STANDBY ||
         con->state == CEPH_CON_S_CLOSED);
 
     ceph_con_reset_protocol(con);
 
     if (ceph_con_flag_test(con, CEPH_CON_F_LOSSYTX)) {
         dout("fault on LOSSYTX channel, marking CLOSED\n");
         con->state = CEPH_CON_S_CLOSED;
         return;
     }
 
     /* Requeue anything that hasn't been acked */
     list_splice_init(&con->out_sent, &con->out_queue);
 
     /* If there are no messages queued or keepalive pending, place
      * the connection in a STANDBY state */
     if (list_empty(&con->out_queue) &&
         !ceph_con_flag_test(con, CEPH_CON_F_KEEPALIVE_PENDING)) {
         dout("fault %p setting STANDBY clearing WRITE_PENDING\n", con);
         ceph_con_flag_clear(con, CEPH_CON_F_WRITE_PENDING);
         con->state = CEPH_CON_S_STANDBY;
     } else {
         /* retry after a delay. */
         con->state = CEPH_CON_S_PREOPEN;
         if (!con->delay) {
             con->delay = BASE_DELAY_INTERVAL;
         } else if (con->delay < MAX_DELAY_INTERVAL) {
             con->delay *= 2;
             if (con->delay > MAX_DELAY_INTERVAL)
                 con->delay = MAX_DELAY_INTERVAL;
         }
         ceph_con_flag_set(con, CEPH_CON_F_BACKOFF);
         queue_con(con);
     }
 }
 
 void ceph_messenger_reset_nonce(struct ceph_messenger *msgr)
 {
     u32 nonce = le32_to_cpu(msgr->inst.addr.nonce) + 1000000;
     msgr->inst.addr.nonce = cpu_to_le32(nonce);
     ceph_encode_my_addr(msgr);
 }
 
 /*
  * initialize a new messenger instance
  */
 void ceph_messenger_init(struct ceph_messenger *msgr,
              struct ceph_entity_addr *myaddr)
 {
     spin_lock_init(&msgr->global_seq_lock);
 
     if (myaddr) {
         memcpy(&msgr->inst.addr.in_addr, &myaddr->in_addr,
                sizeof(msgr->inst.addr.in_addr));
         ceph_addr_set_port(&msgr->inst.addr, 0);
     }
 
     /*
      * Since nautilus, clients are identified using type ANY.
      * For msgr1, ceph_encode_banner_addr() munges it to NONE.
      */
     msgr->inst.addr.type = CEPH_ENTITY_ADDR_TYPE_ANY;
 
     /* generate a random non-zero nonce */
     do {
         get_random_bytes(&msgr->inst.addr.nonce,
                  sizeof(msgr->inst.addr.nonce));
     } while (!msgr->inst.addr.nonce);
     ceph_encode_my_addr(msgr);
 
     atomic_set(&msgr->stopping, 0);
     write_pnet(&msgr->net, get_net(current->nsproxy->net_ns));
 
     dout("%s %p\n", __func__, msgr);
 }
 
 void ceph_messenger_fini(struct ceph_messenger *msgr)
 {
     put_net(read_pnet(&msgr->net));
 }
 
 static void msg_con_set(struct ceph_msg *msg, struct ceph_connection *con)
 {
     if (msg->con)
         msg->con->ops->put(msg->con);
 
     msg->con = con ? con->ops->get(con) : NULL;
     BUG_ON(msg->con != con);
 }
 
 static void clear_standby(struct ceph_connection *con)
 {
     /* come back from STANDBY? */
     if (con->state == CEPH_CON_S_STANDBY) {
         dout("clear_standby %p and ++connect_seq\n", con);
         con->state = CEPH_CON_S_PREOPEN;
         con->v1.connect_seq++;
         WARN_ON(ceph_con_flag_test(con, CEPH_CON_F_WRITE_PENDING));
         WARN_ON(ceph_con_flag_test(con, CEPH_CON_F_KEEPALIVE_PENDING));
     }
 }
 
 /*
  * Queue up an outgoing message on the given connection.
  *
  * Consumes a ref on @msg.
  */
 void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
 {
     /* set src+dst */
     msg->hdr.src = con->msgr->inst.name;
     BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
     msg->needs_out_seq = true;
 
     mutex_lock(&con->mutex);
 
     if (con->state == CEPH_CON_S_CLOSED) {
         dout("con_send %p closed, dropping %p\n", con, msg);
         ceph_msg_put(msg);
         mutex_unlock(&con->mutex);
         return;
     }
 
     msg_con_set(msg, con);
 
     BUG_ON(!list_empty(&msg->list_head));
     list_add_tail(&msg->list_head, &con->out_queue);
     dout("----- %p to %s%lld %d=%s len %d+%d+%d -----\n", msg,
          ENTITY_NAME(con->peer_name), le16_to_cpu(msg->hdr.type),
          ceph_msg_type_name(le16_to_cpu(msg->hdr.type)),
          le32_to_cpu(msg->hdr.front_len),
          le32_to_cpu(msg->hdr.middle_len),
          le32_to_cpu(msg->hdr.data_len));
 
     clear_standby(con);
     mutex_unlock(&con->mutex);
 
     /* if there wasn't anything waiting to send before, queue
      * new work */
     if (!ceph_con_flag_test_and_set(con, CEPH_CON_F_WRITE_PENDING))
         queue_con(con);
 }
 EXPORT_SYMBOL(ceph_con_send);
 
 /*
  * Revoke a message that was previously queued for send
  */
 void ceph_msg_revoke(struct ceph_msg *msg)
 {
     struct ceph_connection *con = msg->con;
 
     if (!con) {
         dout("%s msg %p null con\n", __func__, msg);
         return;     /* Message not in our possession */
     }
 
     mutex_lock(&con->mutex);
     if (list_empty(&msg->list_head)) {
         WARN_ON(con->out_msg == msg);
         dout("%s con %p msg %p not linked\n", __func__, con, msg);
         mutex_unlock(&con->mutex);
         return;
     }
 
     dout("%s con %p msg %p was linked\n", __func__, con, msg);
     msg->hdr.seq = 0;
     ceph_msg_remove(msg);
 
     if (con->out_msg == msg) {
         WARN_ON(con->state != CEPH_CON_S_OPEN);
         dout("%s con %p msg %p was sending\n", __func__, con, msg);
         if (ceph_msgr2(from_msgr(con->msgr)))
             ceph_con_v2_revoke(con);
         else
             ceph_con_v1_revoke(con);
         ceph_msg_put(con->out_msg);
         con->out_msg = NULL;
     } else {
         dout("%s con %p msg %p not current, out_msg %p\n", __func__,
              con, msg, con->out_msg);
     }
     mutex_unlock(&con->mutex);
 }
 
 /*
  * Revoke a message that we may be reading data into
  */
 void ceph_msg_revoke_incoming(struct ceph_msg *msg)
 {
     struct ceph_connection *con = msg->con;
 
     if (!con) {
         dout("%s msg %p null con\n", __func__, msg);
         return;     /* Message not in our possession */
     }
 
     mutex_lock(&con->mutex);
     if (con->in_msg == msg) {
         WARN_ON(con->state != CEPH_CON_S_OPEN);
         dout("%s con %p msg %p was recving\n", __func__, con, msg);
         if (ceph_msgr2(from_msgr(con->msgr)))
             ceph_con_v2_revoke_incoming(con);
         else
             ceph_con_v1_revoke_incoming(con);
         ceph_msg_put(con->in_msg);
         con->in_msg = NULL;
     } else {
         dout("%s con %p msg %p not current, in_msg %p\n", __func__,
              con, msg, con->in_msg);
     }
     mutex_unlock(&con->mutex);
 }
 
 /*
  * Queue a keepalive byte to ensure the tcp connection is alive.
  */
 void ceph_con_keepalive(struct ceph_connection *con)
 {
     dout("con_keepalive %p\n", con);
     mutex_lock(&con->mutex);
     clear_standby(con);
     ceph_con_flag_set(con, CEPH_CON_F_KEEPALIVE_PENDING);
     mutex_unlock(&con->mutex);
 
     if (!ceph_con_flag_test_and_set(con, CEPH_CON_F_WRITE_PENDING))
         queue_con(con);
 }
 EXPORT_SYMBOL(ceph_con_keepalive);
 
 bool ceph_con_keepalive_expired(struct ceph_connection *con,
                    unsigned long interval)
 {
     if (interval > 0 &&
         (con->peer_features & CEPH_FEATURE_MSGR_KEEPALIVE2)) {
         struct timespec64 now;
         struct timespec64 ts;
         ktime_get_real_ts64(&now);
         jiffies_to_timespec64(interval, &ts);
         ts = timespec64_add(con->last_keepalive_ack, ts);
         return timespec64_compare(&now, &ts) >= 0;
     }
     return false;
 }
 
 static struct ceph_msg_data *ceph_msg_data_add(struct ceph_msg *msg)
 {
     BUG_ON(msg->num_data_items >= msg->max_data_items);
     return &msg->data[msg->num_data_items++];
 }
 
 static void ceph_msg_data_destroy(struct ceph_msg_data *data)
 {
     if (data->type == CEPH_MSG_DATA_PAGES && data->own_pages) {
         int num_pages = calc_pages_for(data->alignment, data->length);
         ceph_release_page_vector(data->pages, num_pages);
     } else if (data->type == CEPH_MSG_DATA_PAGELIST) {
         ceph_pagelist_release(data->pagelist);
     }
 }
 
 void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
                  size_t length, size_t alignment, bool own_pages)
 {
     struct ceph_msg_data *data;
 
     BUG_ON(!pages);
     BUG_ON(!length);
 
     data = ceph_msg_data_add(msg);
     data->type = CEPH_MSG_DATA_PAGES;
     data->pages = pages;
     data->length = length;
     data->alignment = alignment & ~PAGE_MASK;
     data->own_pages = own_pages;
 
     msg->data_length += length;
 }
 EXPORT_SYMBOL(ceph_msg_data_add_pages);
 
 void ceph_msg_data_add_pagelist(struct ceph_msg *msg,
                 struct ceph_pagelist *pagelist)
 {
     struct ceph_msg_data *data;
 
     BUG_ON(!pagelist);
     BUG_ON(!pagelist->length);
 
     data = ceph_msg_data_add(msg);
     data->type = CEPH_MSG_DATA_PAGELIST;
     refcount_inc(&pagelist->refcnt);
     data->pagelist = pagelist;
 
     msg->data_length += pagelist->length;
 }
 EXPORT_SYMBOL(ceph_msg_data_add_pagelist);
 
 #ifdef  CONFIG_BLOCK
 void ceph_msg_data_add_bio(struct ceph_msg *msg, struct ceph_bio_iter *bio_pos,
                u32 length)
 {
     struct ceph_msg_data *data;
 
     data = ceph_msg_data_add(msg);
     data->type = CEPH_MSG_DATA_BIO;
     data->bio_pos = *bio_pos;
     data->bio_length = length;
 
     msg->data_length += length;
 }
 EXPORT_SYMBOL(ceph_msg_data_add_bio);
 #endif  /* CONFIG_BLOCK */
 
 void ceph_msg_data_add_bvecs(struct ceph_msg *msg,
                  struct ceph_bvec_iter *bvec_pos)
 {
     struct ceph_msg_data *data;
 
     data = ceph_msg_data_add(msg);
     data->type = CEPH_MSG_DATA_BVECS;
     data->bvec_pos = *bvec_pos;
 
     msg->data_length += bvec_pos->iter.bi_size;
 }
 EXPORT_SYMBOL(ceph_msg_data_add_bvecs);
 
 /*
  * construct a new message with given type, size
  * the new msg has a ref count of 1.
  */
 struct ceph_msg *ceph_msg_new2(int type, int front_len, int max_data_items,
                    gfp_t flags, bool can_fail)
 {
     struct ceph_msg *m;
 
     m = kmem_cache_zalloc(ceph_msg_cache, flags);
     if (m == NULL)
         goto out;
 
     m->hdr.type = cpu_to_le16(type);
     m->hdr.priority = cpu_to_le16(CEPH_MSG_PRIO_DEFAULT);
     m->hdr.front_len = cpu_to_le32(front_len);
 
     INIT_LIST_HEAD(&m->list_head);
     kref_init(&m->kref);
 
     /* front */
     if (front_len) {
         m->front.iov_base = kvmalloc(front_len, flags);
         if (m->front.iov_base == NULL) {
             dout("ceph_msg_new can't allocate %d bytes\n",
                  front_len);
             goto out2;
         }
     } else {
         m->front.iov_base = NULL;
     }
     m->front_alloc_len = m->front.iov_len = front_len;
 
     if (max_data_items) {
         m->data = kmalloc_array(max_data_items, sizeof(*m->data),
                     flags);
         if (!m->data)
             goto out2;
 
         m->max_data_items = max_data_items;
     }
 
     dout("ceph_msg_new %p front %d\n", m, front_len);
     return m;
 
 out2:
     ceph_msg_put(m);
 out:
     if (!can_fail) {
         pr_err("msg_new can't create type %d front %d\n", type,
                front_len);
         WARN_ON(1);
     } else {
         dout("msg_new can't create type %d front %d\n", type,
              front_len);
     }
     return NULL;
 }
 EXPORT_SYMBOL(ceph_msg_new2);
 
 struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags,
                   bool can_fail)
 {
     return ceph_msg_new2(type, front_len, 0, flags, can_fail);
 }
 EXPORT_SYMBOL(ceph_msg_new);
 
 /*
  * Allocate "middle" portion of a message, if it is needed and wasn't
  * allocated by alloc_msg.  This allows us to read a small fixed-size
  * per-type header in the front and then gracefully fail (i.e.,
  * propagate the error to the caller based on info in the front) when
  * the middle is too large.
  */
 static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
 {
     int type = le16_to_cpu(msg->hdr.type);
     int middle_len = le32_to_cpu(msg->hdr.middle_len);
 
     dout("alloc_middle %p type %d %s middle_len %d\n", msg, type,
          ceph_msg_type_name(type), middle_len);
     BUG_ON(!middle_len);
     BUG_ON(msg->middle);
 
     msg->middle = ceph_buffer_new(middle_len, GFP_NOFS);
     if (!msg->middle)
         return -ENOMEM;
     return 0;
 }
 
 /*
  * Allocate a message for receiving an incoming message on a
  * connection, and save the result in con->in_msg.  Uses the
  * connection's private alloc_msg op if available.
  *
  * Returns 0 on success, or a negative error code.
  *
  * On success, if we set *skip = 1:
  *  - the next message should be skipped and ignored.
  *  - con->in_msg == NULL
  * or if we set *skip = 0:
  *  - con->in_msg is non-null.
  * On error (ENOMEM, EAGAIN, ...),
  *  - con->in_msg == NULL
  */
 int ceph_con_in_msg_alloc(struct ceph_connection *con,
               struct ceph_msg_header *hdr, int *skip)
 {
     int middle_len = le32_to_cpu(hdr->middle_len);
     struct ceph_msg *msg;
     int ret = 0;
 
     BUG_ON(con->in_msg != NULL);
     BUG_ON(!con->ops->alloc_msg);
 
     mutex_unlock(&con->mutex);
     msg = con->ops->alloc_msg(con, hdr, skip);
     mutex_lock(&con->mutex);
     if (con->state != CEPH_CON_S_OPEN) {
         if (msg)
             ceph_msg_put(msg);
         return -EAGAIN;
     }
     if (msg) {
         BUG_ON(*skip);
         msg_con_set(msg, con);
         con->in_msg = msg;
     } else {
         /*
          * Null message pointer means either we should skip
          * this message or we couldn't allocate memory.  The
          * former is not an error.
          */
         if (*skip)
             return 0;
 
         con->error_msg = "error allocating memory for incoming message";
         return -ENOMEM;
     }
     memcpy(&con->in_msg->hdr, hdr, sizeof(*hdr));
 
     if (middle_len && !con->in_msg->middle) {
         ret = ceph_alloc_middle(con, con->in_msg);
         if (ret < 0) {
             ceph_msg_put(con->in_msg);
             con->in_msg = NULL;
         }
     }
 
     return ret;
 }
 
 void ceph_con_get_out_msg(struct ceph_connection *con)
 {
     struct ceph_msg *msg;
 
     BUG_ON(list_empty(&con->out_queue));
     msg = list_first_entry(&con->out_queue, struct ceph_msg, list_head);
     WARN_ON(msg->con != con);
 
     /*
      * Put the message on "sent" list using a ref from ceph_con_send().
      * It is put when the message is acked or revoked.
      */
     list_move_tail(&msg->list_head, &con->out_sent);
 
     /*
      * Only assign outgoing seq # if we haven't sent this message
      * yet.  If it is requeued, resend with it's original seq.
      */
     if (msg->needs_out_seq) {
         msg->hdr.seq = cpu_to_le64(++con->out_seq);
         msg->needs_out_seq = false;
 
         if (con->ops->reencode_message)
             con->ops->reencode_message(msg);
     }
 
     /*
      * Get a ref for out_msg.  It is put when we are done sending the
      * message or in case of a fault.
      */
     WARN_ON(con->out_msg);
     con->out_msg = ceph_msg_get(msg);
 }
 
 /*
  * Free a generically kmalloc'd message.
  */
 static void ceph_msg_free(struct ceph_msg *m)
 {
     dout("%s %p\n", __func__, m);
     kvfree(m->front.iov_base);
     kfree(m->data);
     kmem_cache_free(ceph_msg_cache, m);
 }
 
 static void ceph_msg_release(struct kref *kref)
 {
     struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
     int i;
 
     dout("%s %p\n", __func__, m);
     WARN_ON(!list_empty(&m->list_head));
 
     msg_con_set(m, NULL);
 
     /* drop middle, data, if any */
     if (m->middle) {
         ceph_buffer_put(m->middle);
         m->middle = NULL;
     }
 
     for (i = 0; i < m->num_data_items; i++)
         ceph_msg_data_destroy(&m->data[i]);
 
     if (m->pool)
         ceph_msgpool_put(m->pool, m);
     else
         ceph_msg_free(m);
 }
 
 struct ceph_msg *ceph_msg_get(struct ceph_msg *msg)
 {
     dout("%s %p (was %d)\n", __func__, msg,
          kref_read(&msg->kref));
     kref_get(&msg->kref);
     return msg;
 }
 EXPORT_SYMBOL(ceph_msg_get);
 
 void ceph_msg_put(struct ceph_msg *msg)
 {
     dout("%s %p (was %d)\n", __func__, msg,
          kref_read(&msg->kref));
     kref_put(&msg->kref, ceph_msg_release);
 }
 EXPORT_SYMBOL(ceph_msg_put);
 
 void ceph_msg_dump(struct ceph_msg *msg)
 {
     pr_debug("msg_dump %p (front_alloc_len %d length %zd)\n", msg,
          msg->front_alloc_len, msg->data_length);
     print_hex_dump(KERN_DEBUG, "header: ",
                DUMP_PREFIX_OFFSET, 16, 1,
                &msg->hdr, sizeof(msg->hdr), true);
     print_hex_dump(KERN_DEBUG, " front: ",
                DUMP_PREFIX_OFFSET, 16, 1,
                msg->front.iov_base, msg->front.iov_len, true);
     if (msg->middle)
         print_hex_dump(KERN_DEBUG, "middle: ",
                    DUMP_PREFIX_OFFSET, 16, 1,
                    msg->middle->vec.iov_base,
                    msg->middle->vec.iov_len, true);
     print_hex_dump(KERN_DEBUG, "footer: ",
                DUMP_PREFIX_OFFSET, 16, 1,
                &msg->footer, sizeof(msg->footer), true);
 }
 EXPORT_SYMBOL(ceph_msg_dump);

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