linux/net/ceph/messenger.c
Chunwei Chen 178eda29ca libceph: fix corruption when using page_count 0 page in rbd
It has been reported that using ZFSonLinux on rbd will result in memory
corruption. The bug report can be found here:

https://github.com/zfsonlinux/spl/issues/241
http://tracker.ceph.com/issues/7790

The reason is that ZFS will send pages with page_count 0 into rbd, which in
turns send them to tcp_sendpage. However, tcp_sendpage cannot deal with
page_count 0, as it will do get_page and put_page, and erroneously free the
page.

This type of issue has been noted before, and handled in iscsi, drbd,
etc. So, rbd should also handle this. This fix address this issue by fall back
to slower sendmsg when page_count 0 detected.

Cc: Sage Weil <sage@inktank.com>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Reviewed-by: Ilya Dryomov <ilya.dryomov@inktank.com>
2014-05-16 21:29:26 +04:00

3335 lines
82 KiB
C

#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/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>
#define list_entry_next(pos, member) \
list_entry(pos->member.next, typeof(*pos), member)
/*
* 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 */
/*
* connection states
*/
#define CON_STATE_CLOSED 1 /* -> PREOPEN */
#define CON_STATE_PREOPEN 2 /* -> CONNECTING, CLOSED */
#define CON_STATE_CONNECTING 3 /* -> NEGOTIATING, CLOSED */
#define CON_STATE_NEGOTIATING 4 /* -> OPEN, CLOSED */
#define CON_STATE_OPEN 5 /* -> STANDBY, CLOSED */
#define CON_STATE_STANDBY 6 /* -> PREOPEN, CLOSED */
/*
* ceph_connection flag bits
*/
#define CON_FLAG_LOSSYTX 0 /* we can close channel or drop
* messages on errors */
#define CON_FLAG_KEEPALIVE_PENDING 1 /* we need to send a keepalive */
#define CON_FLAG_WRITE_PENDING 2 /* we have data ready to send */
#define CON_FLAG_SOCK_CLOSED 3 /* socket state changed to closed */
#define CON_FLAG_BACKOFF 4 /* need to retry queuing delayed work */
static bool con_flag_valid(unsigned long con_flag)
{
switch (con_flag) {
case CON_FLAG_LOSSYTX:
case CON_FLAG_KEEPALIVE_PENDING:
case CON_FLAG_WRITE_PENDING:
case CON_FLAG_SOCK_CLOSED:
case CON_FLAG_BACKOFF:
return true;
default:
return false;
}
}
static void con_flag_clear(struct ceph_connection *con, unsigned long con_flag)
{
BUG_ON(!con_flag_valid(con_flag));
clear_bit(con_flag, &con->flags);
}
static void con_flag_set(struct ceph_connection *con, unsigned long con_flag)
{
BUG_ON(!con_flag_valid(con_flag));
set_bit(con_flag, &con->flags);
}
static bool 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);
}
static bool 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);
}
static bool 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;
static struct kmem_cache *ceph_msg_data_cache;
/* static tag bytes (protocol control messages) */
static char tag_msg = CEPH_MSGR_TAG_MSG;
static char tag_ack = CEPH_MSGR_TAG_ACK;
static char tag_keepalive = CEPH_MSGR_TAG_KEEPALIVE;
#ifdef CONFIG_LOCKDEP
static struct lock_class_key socket_class;
#endif
/*
* When skipping (ignoring) a block of input we read it into a "skip
* buffer," which is this many bytes in size.
*/
#define SKIP_BUF_SIZE 1024
static void queue_con(struct ceph_connection *con);
static void con_work(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);
static struct page *zero_page; /* used in certain error cases */
const char *ceph_pr_addr(const struct sockaddr_storage *ss)
{
int i;
char *s;
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, "%pI4:%hu", &in4->sin_addr,
ntohs(in4->sin_port));
break;
case AF_INET6:
snprintf(s, MAX_ADDR_STR_LEN, "[%pI6c]:%hu", &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);
static void encode_my_addr(struct ceph_messenger *msgr)
{
memcpy(&msgr->my_enc_addr, &msgr->inst.addr, sizeof(msgr->my_enc_addr));
ceph_encode_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_create("ceph_msg",
sizeof (struct ceph_msg),
__alignof__(struct ceph_msg), 0, NULL);
if (!ceph_msg_cache)
return -ENOMEM;
BUG_ON(ceph_msg_data_cache);
ceph_msg_data_cache = kmem_cache_create("ceph_msg_data",
sizeof (struct ceph_msg_data),
__alignof__(struct ceph_msg_data),
0, NULL);
if (ceph_msg_data_cache)
return 0;
kmem_cache_destroy(ceph_msg_cache);
ceph_msg_cache = NULL;
return -ENOMEM;
}
static void ceph_msgr_slab_exit(void)
{
BUG_ON(!ceph_msg_data_cache);
kmem_cache_destroy(ceph_msg_data_cache);
ceph_msg_data_cache = NULL;
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;
}
ceph_msgr_slab_exit();
BUG_ON(zero_page == NULL);
kunmap(zero_page);
page_cache_release(zero_page);
zero_page = NULL;
}
int ceph_msgr_init(void)
{
BUG_ON(zero_page != NULL);
zero_page = ZERO_PAGE(0);
page_cache_get(zero_page);
if (ceph_msgr_slab_init())
return -ENOMEM;
ceph_msgr_wq = alloc_workqueue("ceph-msgr", 0, 0);
if (ceph_msgr_wq)
return 0;
pr_err("msgr_init failed to create workqueue\n");
_ceph_msgr_exit();
return -ENOMEM;
}
EXPORT_SYMBOL(ceph_msgr_init);
void ceph_msgr_exit(void)
{
BUG_ON(ceph_msgr_wq == NULL);
_ceph_msgr_exit();
}
EXPORT_SYMBOL(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 on %p state = %lu, 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 (con_flag_test(con, CON_FLAG_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 = %lu sk_state = %u\n", __func__,
con, con->state, sk->sk_state);
switch (sk->sk_state) {
case TCP_CLOSE:
dout("%s TCP_CLOSE\n", __func__);
case TCP_CLOSE_WAIT:
dout("%s TCP_CLOSE_WAIT\n", __func__);
con_sock_state_closing(con);
con_flag_set(con, CON_FLAG_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.
*/
static int ceph_tcp_connect(struct ceph_connection *con)
{
struct sockaddr_storage *paddr = &con->peer_addr.in_addr;
struct socket *sock;
int ret;
BUG_ON(con->sock);
ret = sock_create_kern(con->peer_addr.in_addr.ss_family, SOCK_STREAM,
IPPROTO_TCP, &sock);
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);
dout("connect %s\n", ceph_pr_addr(&con->peer_addr.in_addr));
con_sock_state_connecting(con);
ret = sock->ops->connect(sock, (struct sockaddr *)paddr, sizeof(*paddr),
O_NONBLOCK);
if (ret == -EINPROGRESS) {
dout("connect %s EINPROGRESS sk_state = %u\n",
ceph_pr_addr(&con->peer_addr.in_addr),
sock->sk->sk_state);
} else if (ret < 0) {
pr_err("connect %s error %d\n",
ceph_pr_addr(&con->peer_addr.in_addr), ret);
sock_release(sock);
con->error_msg = "connect error";
return ret;
}
con->sock = sock;
return 0;
}
static int ceph_tcp_recvmsg(struct socket *sock, void *buf, size_t len)
{
struct kvec iov = {buf, len};
struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
int r;
r = kernel_recvmsg(sock, &msg, &iov, 1, len, msg.msg_flags);
if (r == -EAGAIN)
r = 0;
return r;
}
static int ceph_tcp_recvpage(struct socket *sock, struct page *page,
int page_offset, size_t length)
{
void *kaddr;
int ret;
BUG_ON(page_offset + length > PAGE_SIZE);
kaddr = kmap(page);
BUG_ON(!kaddr);
ret = ceph_tcp_recvmsg(sock, kaddr + page_offset, length);
kunmap(page);
return ret;
}
/*
* write something. @more is true if caller will be sending more data
* shortly.
*/
static int ceph_tcp_sendmsg(struct socket *sock, struct kvec *iov,
size_t kvlen, size_t len, int more)
{
struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
int r;
if (more)
msg.msg_flags |= MSG_MORE;
else
msg.msg_flags |= MSG_EOR; /* superfluous, but what the hell */
r = kernel_sendmsg(sock, &msg, iov, kvlen, len);
if (r == -EAGAIN)
r = 0;
return r;
}
static int __ceph_tcp_sendpage(struct socket *sock, struct page *page,
int offset, size_t size, bool more)
{
int flags = MSG_DONTWAIT | MSG_NOSIGNAL | (more ? MSG_MORE : MSG_EOR);
int ret;
ret = kernel_sendpage(sock, page, offset, size, flags);
if (ret == -EAGAIN)
ret = 0;
return ret;
}
static int ceph_tcp_sendpage(struct socket *sock, struct page *page,
int offset, size_t size, bool more)
{
int ret;
struct kvec iov;
/* sendpage cannot properly handle pages with page_count == 0,
* we need to fallback to sendmsg if that's the case */
if (page_count(page) >= 1)
return __ceph_tcp_sendpage(sock, page, offset, size, more);
iov.iov_base = kmap(page) + offset;
iov.iov_len = size;
ret = ceph_tcp_sendmsg(sock, &iov, 1, size, more);
kunmap(page);
return ret;
}
/*
* Shutdown/close the socket for the given connection.
*/
static int con_close_socket(struct ceph_connection *con)
{
int rc = 0;
dout("con_close_socket on %p sock %p\n", 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.
*/
con_flag_clear(con, CON_FLAG_SOCK_CLOSED);
con_sock_state_closed(con);
return rc;
}
/*
* 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);
BUG_ON(msg->con == NULL);
msg->con->ops->put(msg->con);
msg->con = NULL;
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);
}
}
static void reset_connection(struct ceph_connection *con)
{
/* reset connection, out_queue, msg_ and connect_seq */
/* discard existing out_queue and msg_seq */
dout("reset_connection %p\n", con);
ceph_msg_remove_list(&con->out_queue);
ceph_msg_remove_list(&con->out_sent);
if (con->in_msg) {
BUG_ON(con->in_msg->con != con);
con->in_msg->con = NULL;
ceph_msg_put(con->in_msg);
con->in_msg = NULL;
con->ops->put(con);
}
con->connect_seq = 0;
con->out_seq = 0;
if (con->out_msg) {
ceph_msg_put(con->out_msg);
con->out_msg = NULL;
}
con->in_seq = 0;
con->in_seq_acked = 0;
}
/*
* 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.in_addr));
con->state = CON_STATE_CLOSED;
con_flag_clear(con, CON_FLAG_LOSSYTX); /* so we retry next connect */
con_flag_clear(con, CON_FLAG_KEEPALIVE_PENDING);
con_flag_clear(con, CON_FLAG_WRITE_PENDING);
con_flag_clear(con, CON_FLAG_BACKOFF);
reset_connection(con);
con->peer_global_seq = 0;
cancel_delayed_work(&con->work);
con_close_socket(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->in_addr));
WARN_ON(con->state != CON_STATE_CLOSED);
con->state = CON_STATE_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)
{
return con->connect_seq > 0;
}
/*
* 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, con_work);
con->state = CON_STATE_CLOSED;
}
EXPORT_SYMBOL(ceph_con_init);
/*
* We maintain a global counter to order connection attempts. Get
* a unique seq greater than @gt.
*/
static u32 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;
}
static void con_out_kvec_reset(struct ceph_connection *con)
{
con->out_kvec_left = 0;
con->out_kvec_bytes = 0;
con->out_kvec_cur = &con->out_kvec[0];
}
static void con_out_kvec_add(struct ceph_connection *con,
size_t size, void *data)
{
int index;
index = con->out_kvec_left;
BUG_ON(index >= ARRAY_SIZE(con->out_kvec));
con->out_kvec[index].iov_len = size;
con->out_kvec[index].iov_base = data;
con->out_kvec_left++;
con->out_kvec_bytes += size;
}
#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 bio *bio;
BUG_ON(data->type != CEPH_MSG_DATA_BIO);
bio = data->bio;
BUG_ON(!bio);
cursor->resid = min(length, data->bio_length);
cursor->bio = bio;
cursor->bvec_iter = bio->bi_iter;
cursor->last_piece =
cursor->resid <= bio_iter_len(bio, cursor->bvec_iter);
}
static struct page *ceph_msg_data_bio_next(struct ceph_msg_data_cursor *cursor,
size_t *page_offset,
size_t *length)
{
struct ceph_msg_data *data = cursor->data;
struct bio *bio;
struct bio_vec bio_vec;
BUG_ON(data->type != CEPH_MSG_DATA_BIO);
bio = cursor->bio;
BUG_ON(!bio);
bio_vec = bio_iter_iovec(bio, cursor->bvec_iter);
*page_offset = (size_t) bio_vec.bv_offset;
BUG_ON(*page_offset >= PAGE_SIZE);
if (cursor->last_piece) /* pagelist offset is always 0 */
*length = cursor->resid;
else
*length = (size_t) bio_vec.bv_len;
BUG_ON(*length > cursor->resid);
BUG_ON(*page_offset + *length > PAGE_SIZE);
return bio_vec.bv_page;
}
static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
size_t bytes)
{
struct bio *bio;
struct bio_vec bio_vec;
BUG_ON(cursor->data->type != CEPH_MSG_DATA_BIO);
bio = cursor->bio;
BUG_ON(!bio);
bio_vec = bio_iter_iovec(bio, cursor->bvec_iter);
/* Advance the cursor offset */
BUG_ON(cursor->resid < bytes);
cursor->resid -= bytes;
bio_advance_iter(bio, &cursor->bvec_iter, bytes);
if (bytes < bio_vec.bv_len)
return false; /* more bytes to process in this segment */
/* Move on to the next segment, and possibly the next bio */
if (!cursor->bvec_iter.bi_size) {
bio = bio->bi_next;
cursor->bio = bio;
if (bio)
cursor->bvec_iter = bio->bi_iter;
else
memset(&cursor->bvec_iter, 0,
sizeof(cursor->bvec_iter));
}
if (!cursor->last_piece) {
BUG_ON(!cursor->resid);
BUG_ON(!bio);
/* A short read is OK, so use <= rather than == */
if (cursor->resid <= bio_iter_len(bio, cursor->bvec_iter))
cursor->last_piece = true;
}
return true;
}
#endif /* CONFIG_BLOCK */
/*
* 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 = (size_t)cursor->page_offset + length <= 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_entry_next(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_NONE:
default:
/* BUG(); */
break;
}
cursor->need_crc = true;
}
static void ceph_msg_data_cursor_init(struct ceph_msg *msg, size_t length)
{
struct ceph_msg_data_cursor *cursor = &msg->cursor;
struct ceph_msg_data *data;
BUG_ON(!length);
BUG_ON(length > msg->data_length);
BUG_ON(list_empty(&msg->data));
cursor->data_head = &msg->data;
cursor->total_resid = length;
data = list_first_entry(&msg->data, struct ceph_msg_data, links);
cursor->data = 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.
*/
static 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_NONE:
default:
page = NULL;
break;
}
BUG_ON(!page);
BUG_ON(*page_offset + *length > PAGE_SIZE);
BUG_ON(!*length);
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.
*/
static bool 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_NONE:
default:
BUG();
break;
}
cursor->total_resid -= bytes;
if (!cursor->resid && cursor->total_resid) {
WARN_ON(!cursor->last_piece);
BUG_ON(list_is_last(&cursor->data->links, cursor->data_head));
cursor->data = list_entry_next(cursor->data, links);
__ceph_msg_data_cursor_init(cursor);
new_piece = true;
}
cursor->need_crc = new_piece;
return new_piece;
}
static void prepare_message_data(struct ceph_msg *msg, u32 data_len)
{
BUG_ON(!msg);
BUG_ON(!data_len);
/* Initialize data cursor */
ceph_msg_data_cursor_init(msg, (size_t)data_len);
}
/*
* Prepare footer for currently outgoing message, and finish things
* off. Assumes out_kvec* are already valid.. we just add on to the end.
*/
static void prepare_write_message_footer(struct ceph_connection *con)
{
struct ceph_msg *m = con->out_msg;
int v = con->out_kvec_left;
m->footer.flags |= CEPH_MSG_FOOTER_COMPLETE;
dout("prepare_write_message_footer %p\n", con);
con->out_kvec_is_msg = true;
con->out_kvec[v].iov_base = &m->footer;
con->out_kvec[v].iov_len = sizeof(m->footer);
con->out_kvec_bytes += sizeof(m->footer);
con->out_kvec_left++;
con->out_more = m->more_to_follow;
con->out_msg_done = true;
}
/*
* Prepare headers for the next outgoing message.
*/
static void prepare_write_message(struct ceph_connection *con)
{
struct ceph_msg *m;
u32 crc;
con_out_kvec_reset(con);
con->out_kvec_is_msg = true;
con->out_msg_done = false;
/* Sneak an ack in there first? If we can get it into the same
* TCP packet that's a good thing. */
if (con->in_seq > con->in_seq_acked) {
con->in_seq_acked = con->in_seq;
con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
con_out_kvec_add(con, sizeof (con->out_temp_ack),
&con->out_temp_ack);
}
BUG_ON(list_empty(&con->out_queue));
m = list_first_entry(&con->out_queue, struct ceph_msg, list_head);
con->out_msg = m;
BUG_ON(m->con != con);
/* put message on sent list */
ceph_msg_get(m);
list_move_tail(&m->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 (m->needs_out_seq) {
m->hdr.seq = cpu_to_le64(++con->out_seq);
m->needs_out_seq = false;
}
WARN_ON(m->data_length != le32_to_cpu(m->hdr.data_len));
dout("prepare_write_message %p seq %lld type %d len %d+%d+%zd\n",
m, con->out_seq, le16_to_cpu(m->hdr.type),
le32_to_cpu(m->hdr.front_len), le32_to_cpu(m->hdr.middle_len),
m->data_length);
BUG_ON(le32_to_cpu(m->hdr.front_len) != m->front.iov_len);
/* tag + hdr + front + middle */
con_out_kvec_add(con, sizeof (tag_msg), &tag_msg);
con_out_kvec_add(con, sizeof (m->hdr), &m->hdr);
con_out_kvec_add(con, m->front.iov_len, m->front.iov_base);
if (m->middle)
con_out_kvec_add(con, m->middle->vec.iov_len,
m->middle->vec.iov_base);
/* fill in crc (except data pages), footer */
crc = crc32c(0, &m->hdr, offsetof(struct ceph_msg_header, crc));
con->out_msg->hdr.crc = cpu_to_le32(crc);
con->out_msg->footer.flags = 0;
crc = crc32c(0, m->front.iov_base, m->front.iov_len);
con->out_msg->footer.front_crc = cpu_to_le32(crc);
if (m->middle) {
crc = crc32c(0, m->middle->vec.iov_base,
m->middle->vec.iov_len);
con->out_msg->footer.middle_crc = cpu_to_le32(crc);
} else
con->out_msg->footer.middle_crc = 0;
dout("%s front_crc %u middle_crc %u\n", __func__,
le32_to_cpu(con->out_msg->footer.front_crc),
le32_to_cpu(con->out_msg->footer.middle_crc));
/* is there a data payload? */
con->out_msg->footer.data_crc = 0;
if (m->data_length) {
prepare_message_data(con->out_msg, m->data_length);
con->out_more = 1; /* data + footer will follow */
} else {
/* no, queue up footer too and be done */
prepare_write_message_footer(con);
}
con_flag_set(con, CON_FLAG_WRITE_PENDING);
}
/*
* Prepare an ack.
*/
static void prepare_write_ack(struct ceph_connection *con)
{
dout("prepare_write_ack %p %llu -> %llu\n", con,
con->in_seq_acked, con->in_seq);
con->in_seq_acked = con->in_seq;
con_out_kvec_reset(con);
con_out_kvec_add(con, sizeof (tag_ack), &tag_ack);
con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
con_out_kvec_add(con, sizeof (con->out_temp_ack),
&con->out_temp_ack);
con->out_more = 1; /* more will follow.. eventually.. */
con_flag_set(con, CON_FLAG_WRITE_PENDING);
}
/*
* Prepare to share the seq during handshake
*/
static void prepare_write_seq(struct ceph_connection *con)
{
dout("prepare_write_seq %p %llu -> %llu\n", con,
con->in_seq_acked, con->in_seq);
con->in_seq_acked = con->in_seq;
con_out_kvec_reset(con);
con->out_temp_ack = cpu_to_le64(con->in_seq_acked);
con_out_kvec_add(con, sizeof (con->out_temp_ack),
&con->out_temp_ack);
con_flag_set(con, CON_FLAG_WRITE_PENDING);
}
/*
* Prepare to write keepalive byte.
*/
static void prepare_write_keepalive(struct ceph_connection *con)
{
dout("prepare_write_keepalive %p\n", con);
con_out_kvec_reset(con);
con_out_kvec_add(con, sizeof (tag_keepalive), &tag_keepalive);
con_flag_set(con, CON_FLAG_WRITE_PENDING);
}
/*
* Connection negotiation.
*/
static struct ceph_auth_handshake *get_connect_authorizer(struct ceph_connection *con,
int *auth_proto)
{
struct ceph_auth_handshake *auth;
if (!con->ops->get_authorizer) {
con->out_connect.authorizer_protocol = CEPH_AUTH_UNKNOWN;
con->out_connect.authorizer_len = 0;
return NULL;
}
/* Can't hold the mutex while getting authorizer */
mutex_unlock(&con->mutex);
auth = con->ops->get_authorizer(con, auth_proto, con->auth_retry);
mutex_lock(&con->mutex);
if (IS_ERR(auth))
return auth;
if (con->state != CON_STATE_NEGOTIATING)
return ERR_PTR(-EAGAIN);
con->auth_reply_buf = auth->authorizer_reply_buf;
con->auth_reply_buf_len = auth->authorizer_reply_buf_len;
return auth;
}
/*
* We connected to a peer and are saying hello.
*/
static void prepare_write_banner(struct ceph_connection *con)
{
con_out_kvec_add(con, strlen(CEPH_BANNER), CEPH_BANNER);
con_out_kvec_add(con, sizeof (con->msgr->my_enc_addr),
&con->msgr->my_enc_addr);
con->out_more = 0;
con_flag_set(con, CON_FLAG_WRITE_PENDING);
}
static int prepare_write_connect(struct ceph_connection *con)
{
unsigned int global_seq = get_global_seq(con->msgr, 0);
int proto;
int auth_proto;
struct ceph_auth_handshake *auth;
switch (con->peer_name.type) {
case CEPH_ENTITY_TYPE_MON:
proto = CEPH_MONC_PROTOCOL;
break;
case CEPH_ENTITY_TYPE_OSD:
proto = CEPH_OSDC_PROTOCOL;
break;
case CEPH_ENTITY_TYPE_MDS:
proto = CEPH_MDSC_PROTOCOL;
break;
default:
BUG();
}
dout("prepare_write_connect %p cseq=%d gseq=%d proto=%d\n", con,
con->connect_seq, global_seq, proto);
con->out_connect.features = cpu_to_le64(con->msgr->supported_features);
con->out_connect.host_type = cpu_to_le32(CEPH_ENTITY_TYPE_CLIENT);
con->out_connect.connect_seq = cpu_to_le32(con->connect_seq);
con->out_connect.global_seq = cpu_to_le32(global_seq);
con->out_connect.protocol_version = cpu_to_le32(proto);
con->out_connect.flags = 0;
auth_proto = CEPH_AUTH_UNKNOWN;
auth = get_connect_authorizer(con, &auth_proto);
if (IS_ERR(auth))
return PTR_ERR(auth);
con->out_connect.authorizer_protocol = cpu_to_le32(auth_proto);
con->out_connect.authorizer_len = auth ?
cpu_to_le32(auth->authorizer_buf_len) : 0;
con_out_kvec_add(con, sizeof (con->out_connect),
&con->out_connect);
if (auth && auth->authorizer_buf_len)
con_out_kvec_add(con, auth->authorizer_buf_len,
auth->authorizer_buf);
con->out_more = 0;
con_flag_set(con, CON_FLAG_WRITE_PENDING);
return 0;
}
/*
* write as much of pending kvecs to the socket as we can.
* 1 -> done
* 0 -> socket full, but more to do
* <0 -> error
*/
static int write_partial_kvec(struct ceph_connection *con)
{
int ret;
dout("write_partial_kvec %p %d left\n", con, con->out_kvec_bytes);
while (con->out_kvec_bytes > 0) {
ret = ceph_tcp_sendmsg(con->sock, con->out_kvec_cur,
con->out_kvec_left, con->out_kvec_bytes,
con->out_more);
if (ret <= 0)
goto out;
con->out_kvec_bytes -= ret;
if (con->out_kvec_bytes == 0)
break; /* done */
/* account for full iov entries consumed */
while (ret >= con->out_kvec_cur->iov_len) {
BUG_ON(!con->out_kvec_left);
ret -= con->out_kvec_cur->iov_len;
con->out_kvec_cur++;
con->out_kvec_left--;
}
/* and for a partially-consumed entry */
if (ret) {
con->out_kvec_cur->iov_len -= ret;
con->out_kvec_cur->iov_base += ret;
}
}
con->out_kvec_left = 0;
con->out_kvec_is_msg = false;
ret = 1;
out:
dout("write_partial_kvec %p %d left in %d kvecs ret = %d\n", con,
con->out_kvec_bytes, con->out_kvec_left, ret);
return ret; /* done! */
}
static 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;
}
/*
* Write as much message data payload as we can. If we finish, queue
* up the footer.
* 1 -> done, footer is now queued in out_kvec[].
* 0 -> socket full, but more to do
* <0 -> error
*/
static int write_partial_message_data(struct ceph_connection *con)
{
struct ceph_msg *msg = con->out_msg;
struct ceph_msg_data_cursor *cursor = &msg->cursor;
bool do_datacrc = !con->msgr->nocrc;
u32 crc;
dout("%s %p msg %p\n", __func__, con, msg);
if (list_empty(&msg->data))
return -EINVAL;
/*
* Iterate through each page that contains data to be
* written, and send as much as possible for each.
*
* If we are calculating the data crc (the default), we will
* need to map the page. If we have no pages, they have
* been revoked, so use the zero page.
*/
crc = do_datacrc ? le32_to_cpu(msg->footer.data_crc) : 0;
while (cursor->resid) {
struct page *page;
size_t page_offset;
size_t length;
bool last_piece;
bool need_crc;
int ret;
page = ceph_msg_data_next(&msg->cursor, &page_offset, &length,
&last_piece);
ret = ceph_tcp_sendpage(con->sock, page, page_offset,
length, last_piece);
if (ret <= 0) {
if (do_datacrc)
msg->footer.data_crc = cpu_to_le32(crc);
return ret;
}
if (do_datacrc && cursor->need_crc)
crc = ceph_crc32c_page(crc, page, page_offset, length);
need_crc = ceph_msg_data_advance(&msg->cursor, (size_t)ret);
}
dout("%s %p msg %p done\n", __func__, con, msg);
/* prepare and queue up footer, too */
if (do_datacrc)
msg->footer.data_crc = cpu_to_le32(crc);
else
msg->footer.flags |= CEPH_MSG_FOOTER_NOCRC;
con_out_kvec_reset(con);
prepare_write_message_footer(con);
return 1; /* must return > 0 to indicate success */
}
/*
* write some zeros
*/
static int write_partial_skip(struct ceph_connection *con)
{
int ret;
while (con->out_skip > 0) {
size_t size = min(con->out_skip, (int) PAGE_CACHE_SIZE);
ret = ceph_tcp_sendpage(con->sock, zero_page, 0, size, true);
if (ret <= 0)
goto out;
con->out_skip -= ret;
}
ret = 1;
out:
return ret;
}
/*
* Prepare to read connection handshake, or an ack.
*/
static void prepare_read_banner(struct ceph_connection *con)
{
dout("prepare_read_banner %p\n", con);
con->in_base_pos = 0;
}
static void prepare_read_connect(struct ceph_connection *con)
{
dout("prepare_read_connect %p\n", con);
con->in_base_pos = 0;
}
static void prepare_read_ack(struct ceph_connection *con)
{
dout("prepare_read_ack %p\n", con);
con->in_base_pos = 0;
}
static void prepare_read_seq(struct ceph_connection *con)
{
dout("prepare_read_seq %p\n", con);
con->in_base_pos = 0;
con->in_tag = CEPH_MSGR_TAG_SEQ;
}
static void prepare_read_tag(struct ceph_connection *con)
{
dout("prepare_read_tag %p\n", con);
con->in_base_pos = 0;
con->in_tag = CEPH_MSGR_TAG_READY;
}
/*
* Prepare to read a message.
*/
static int prepare_read_message(struct ceph_connection *con)
{
dout("prepare_read_message %p\n", con);
BUG_ON(con->in_msg != NULL);
con->in_base_pos = 0;
con->in_front_crc = con->in_middle_crc = con->in_data_crc = 0;
return 0;
}
static int read_partial(struct ceph_connection *con,
int end, int size, void *object)
{
while (con->in_base_pos < end) {
int left = end - con->in_base_pos;
int have = size - left;
int ret = ceph_tcp_recvmsg(con->sock, object + have, left);
if (ret <= 0)
return ret;
con->in_base_pos += ret;
}
return 1;
}
/*
* Read all or part of the connect-side handshake on a new connection
*/
static int read_partial_banner(struct ceph_connection *con)
{
int size;
int end;
int ret;
dout("read_partial_banner %p at %d\n", con, con->in_base_pos);
/* peer's banner */
size = strlen(CEPH_BANNER);
end = size;
ret = read_partial(con, end, size, con->in_banner);
if (ret <= 0)
goto out;
size = sizeof (con->actual_peer_addr);
end += size;
ret = read_partial(con, end, size, &con->actual_peer_addr);
if (ret <= 0)
goto out;
size = sizeof (con->peer_addr_for_me);
end += size;
ret = read_partial(con, end, size, &con->peer_addr_for_me);
if (ret <= 0)
goto out;
out:
return ret;
}
static int read_partial_connect(struct ceph_connection *con)
{
int size;
int end;
int ret;
dout("read_partial_connect %p at %d\n", con, con->in_base_pos);
size = sizeof (con->in_reply);
end = size;
ret = read_partial(con, end, size, &con->in_reply);
if (ret <= 0)
goto out;
size = le32_to_cpu(con->in_reply.authorizer_len);
end += size;
ret = read_partial(con, end, size, con->auth_reply_buf);
if (ret <= 0)
goto out;
dout("read_partial_connect %p tag %d, con_seq = %u, g_seq = %u\n",
con, (int)con->in_reply.tag,
le32_to_cpu(con->in_reply.connect_seq),
le32_to_cpu(con->in_reply.global_seq));
out:
return ret;
}
/*
* Verify the hello banner looks okay.
*/
static int verify_hello(struct ceph_connection *con)
{
if (memcmp(con->in_banner, CEPH_BANNER, strlen(CEPH_BANNER))) {
pr_err("connect to %s got bad banner\n",
ceph_pr_addr(&con->peer_addr.in_addr));
con->error_msg = "protocol error, bad banner";
return -1;
}
return 0;
}
static bool addr_is_blank(struct sockaddr_storage *ss)
{
switch (ss->ss_family) {
case AF_INET:
return ((struct sockaddr_in *)ss)->sin_addr.s_addr == 0;
case AF_INET6:
return
((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[0] == 0 &&
((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[1] == 0 &&
((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[2] == 0 &&
((struct sockaddr_in6 *)ss)->sin6_addr.s6_addr32[3] == 0;
}
return false;
}
static int addr_port(struct sockaddr_storage *ss)
{
switch (ss->ss_family) {
case AF_INET:
return ntohs(((struct sockaddr_in *)ss)->sin_port);
case AF_INET6:
return ntohs(((struct sockaddr_in6 *)ss)->sin6_port);
}
return 0;
}
static void addr_set_port(struct sockaddr_storage *ss, int p)
{
switch (ss->ss_family) {
case AF_INET:
((struct sockaddr_in *)ss)->sin_port = htons(p);
break;
case AF_INET6:
((struct sockaddr_in6 *)ss)->sin6_port = htons(p);
break;
}
}
/*
* Unlike other *_pton function semantics, zero indicates success.
*/
static int ceph_pton(const char *str, size_t len, struct sockaddr_storage *ss,
char delim, const char **ipend)
{
struct sockaddr_in *in4 = (struct sockaddr_in *) ss;
struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) ss;
memset(ss, 0, sizeof(*ss));
if (in4_pton(str, len, (u8 *)&in4->sin_addr.s_addr, delim, ipend)) {
ss->ss_family = AF_INET;
return 0;
}
if (in6_pton(str, len, (u8 *)&in6->sin6_addr.s6_addr, delim, ipend)) {
ss->ss_family = AF_INET6;
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 sockaddr_storage *ss, 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(NULL, name, end - name, NULL, &ip_addr, NULL);
if (ip_len > 0)
ret = ceph_pton(ip_addr, ip_len, ss, -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(ss));
return ret;
}
#else
static inline int ceph_dns_resolve_name(const char *name, size_t namelen,
struct sockaddr_storage *ss, 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 sockaddr_storage *ss, char delim, const char **ipend)
{
int ret;
ret = ceph_pton(name, namelen, ss, delim, ipend);
if (ret)
ret = ceph_dns_resolve_name(name, namelen, ss, 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)
{
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++) {
const char *ipend;
struct sockaddr_storage *ss = &addr[i].in_addr;
int port;
char delim = ',';
if (*p == '[') {
delim = ']';
p++;
}
ret = ceph_parse_server_name(p, end - p, ss, delim, &ipend);
if (ret)
goto bad;
ret = -EINVAL;
p = ipend;
if (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;
}
addr_set_port(ss, port);
dout("parse_ips got %s\n", ceph_pr_addr(ss));
if (p == end)
break;
if (*p != ',')
goto bad;
p++;
}
if (p != end)
goto bad;
if (count)
*count = i + 1;
return 0;
bad:
pr_err("parse_ips bad ip '%.*s'\n", (int)(end - c), c);
return ret;
}
EXPORT_SYMBOL(ceph_parse_ips);
static int process_banner(struct ceph_connection *con)
{
dout("process_banner on %p\n", con);
if (verify_hello(con) < 0)
return -1;
ceph_decode_addr(&con->actual_peer_addr);
ceph_decode_addr(&con->peer_addr_for_me);
/*
* Make sure the other end is who we wanted. note that the other
* end may not yet know their ip address, so if it's 0.0.0.0, give
* them the benefit of the doubt.
*/
if (memcmp(&con->peer_addr, &con->actual_peer_addr,
sizeof(con->peer_addr)) != 0 &&
!(addr_is_blank(&con->actual_peer_addr.in_addr) &&
con->actual_peer_addr.nonce == con->peer_addr.nonce)) {
pr_warning("wrong peer, want %s/%d, got %s/%d\n",
ceph_pr_addr(&con->peer_addr.in_addr),
(int)le32_to_cpu(con->peer_addr.nonce),
ceph_pr_addr(&con->actual_peer_addr.in_addr),
(int)le32_to_cpu(con->actual_peer_addr.nonce));
con->error_msg = "wrong peer at address";
return -1;
}
/*
* did we learn our address?
*/
if (addr_is_blank(&con->msgr->inst.addr.in_addr)) {
int port = addr_port(&con->msgr->inst.addr.in_addr);
memcpy(&con->msgr->inst.addr.in_addr,
&con->peer_addr_for_me.in_addr,
sizeof(con->peer_addr_for_me.in_addr));
addr_set_port(&con->msgr->inst.addr.in_addr, port);
encode_my_addr(con->msgr);
dout("process_banner learned my addr is %s\n",
ceph_pr_addr(&con->msgr->inst.addr.in_addr));
}
return 0;
}
static int process_connect(struct ceph_connection *con)
{
u64 sup_feat = con->msgr->supported_features;
u64 req_feat = con->msgr->required_features;
u64 server_feat = ceph_sanitize_features(
le64_to_cpu(con->in_reply.features));
int ret;
dout("process_connect on %p tag %d\n", con, (int)con->in_tag);
switch (con->in_reply.tag) {
case CEPH_MSGR_TAG_FEATURES:
pr_err("%s%lld %s feature set mismatch,"
" my %llx < server's %llx, missing %llx\n",
ENTITY_NAME(con->peer_name),
ceph_pr_addr(&con->peer_addr.in_addr),
sup_feat, server_feat, server_feat & ~sup_feat);
con->error_msg = "missing required protocol features";
reset_connection(con);
return -1;
case CEPH_MSGR_TAG_BADPROTOVER:
pr_err("%s%lld %s protocol version mismatch,"
" my %d != server's %d\n",
ENTITY_NAME(con->peer_name),
ceph_pr_addr(&con->peer_addr.in_addr),
le32_to_cpu(con->out_connect.protocol_version),
le32_to_cpu(con->in_reply.protocol_version));
con->error_msg = "protocol version mismatch";
reset_connection(con);
return -1;
case CEPH_MSGR_TAG_BADAUTHORIZER:
con->auth_retry++;
dout("process_connect %p got BADAUTHORIZER attempt %d\n", con,
con->auth_retry);
if (con->auth_retry == 2) {
con->error_msg = "connect authorization failure";
return -1;
}
con_out_kvec_reset(con);
ret = prepare_write_connect(con);
if (ret < 0)
return ret;
prepare_read_connect(con);
break;
case CEPH_MSGR_TAG_RESETSESSION:
/*
* If we connected with a large connect_seq but the peer
* has no record of a session with us (no connection, or
* connect_seq == 0), they will send RESETSESION to indicate
* that they must have reset their session, and may have
* dropped messages.
*/
dout("process_connect got RESET peer seq %u\n",
le32_to_cpu(con->in_reply.connect_seq));
pr_err("%s%lld %s connection reset\n",
ENTITY_NAME(con->peer_name),
ceph_pr_addr(&con->peer_addr.in_addr));
reset_connection(con);
con_out_kvec_reset(con);
ret = prepare_write_connect(con);
if (ret < 0)
return ret;
prepare_read_connect(con);
/* Tell ceph about it. */
mutex_unlock(&con->mutex);
pr_info("reset on %s%lld\n", ENTITY_NAME(con->peer_name));
if (con->ops->peer_reset)
con->ops->peer_reset(con);
mutex_lock(&con->mutex);
if (con->state != CON_STATE_NEGOTIATING)
return -EAGAIN;
break;
case CEPH_MSGR_TAG_RETRY_SESSION:
/*
* If we sent a smaller connect_seq than the peer has, try
* again with a larger value.
*/
dout("process_connect got RETRY_SESSION my seq %u, peer %u\n",
le32_to_cpu(con->out_connect.connect_seq),
le32_to_cpu(con->in_reply.connect_seq));
con->connect_seq = le32_to_cpu(con->in_reply.connect_seq);
con_out_kvec_reset(con);
ret = prepare_write_connect(con);
if (ret < 0)
return ret;
prepare_read_connect(con);
break;
case CEPH_MSGR_TAG_RETRY_GLOBAL:
/*
* If we sent a smaller global_seq than the peer has, try
* again with a larger value.
*/
dout("process_connect got RETRY_GLOBAL my %u peer_gseq %u\n",
con->peer_global_seq,
le32_to_cpu(con->in_reply.global_seq));
get_global_seq(con->msgr,
le32_to_cpu(con->in_reply.global_seq));
con_out_kvec_reset(con);
ret = prepare_write_connect(con);
if (ret < 0)
return ret;
prepare_read_connect(con);
break;
case CEPH_MSGR_TAG_SEQ:
case CEPH_MSGR_TAG_READY:
if (req_feat & ~server_feat) {
pr_err("%s%lld %s protocol feature mismatch,"
" my required %llx > server's %llx, need %llx\n",
ENTITY_NAME(con->peer_name),
ceph_pr_addr(&con->peer_addr.in_addr),
req_feat, server_feat, req_feat & ~server_feat);
con->error_msg = "missing required protocol features";
reset_connection(con);
return -1;
}
WARN_ON(con->state != CON_STATE_NEGOTIATING);
con->state = CON_STATE_OPEN;
con->auth_retry = 0; /* we authenticated; clear flag */
con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq);
con->connect_seq++;
con->peer_features = server_feat;
dout("process_connect got READY gseq %d cseq %d (%d)\n",
con->peer_global_seq,
le32_to_cpu(con->in_reply.connect_seq),
con->connect_seq);
WARN_ON(con->connect_seq !=
le32_to_cpu(con->in_reply.connect_seq));
if (con->in_reply.flags & CEPH_MSG_CONNECT_LOSSY)
con_flag_set(con, CON_FLAG_LOSSYTX);
con->delay = 0; /* reset backoff memory */
if (con->in_reply.tag == CEPH_MSGR_TAG_SEQ) {
prepare_write_seq(con);
prepare_read_seq(con);
} else {
prepare_read_tag(con);
}
break;
case CEPH_MSGR_TAG_WAIT:
/*
* If there is a connection race (we are opening
* connections to each other), one of us may just have
* to WAIT. This shouldn't happen if we are the
* client.
*/
pr_err("process_connect got WAIT as client\n");
con->error_msg = "protocol error, got WAIT as client";
return -1;
default:
pr_err("connect protocol error, will retry\n");
con->error_msg = "protocol error, garbage tag during connect";
return -1;
}
return 0;
}
/*
* read (part of) an ack
*/
static int read_partial_ack(struct ceph_connection *con)
{
int size = sizeof (con->in_temp_ack);
int end = size;
return read_partial(con, end, size, &con->in_temp_ack);
}
/*
* We can finally discard anything that's been acked.
*/
static void process_ack(struct ceph_connection *con)
{
struct ceph_msg *m;
u64 ack = le64_to_cpu(con->in_temp_ack);
u64 seq;
while (!list_empty(&con->out_sent)) {
m = list_first_entry(&con->out_sent, struct ceph_msg,
list_head);
seq = le64_to_cpu(m->hdr.seq);
if (seq > ack)
break;
dout("got ack for seq %llu type %d at %p\n", seq,
le16_to_cpu(m->hdr.type), m);
m->ack_stamp = jiffies;
ceph_msg_remove(m);
}
prepare_read_tag(con);
}
static int read_partial_message_section(struct ceph_connection *con,
struct kvec *section,
unsigned int sec_len, u32 *crc)
{
int ret, left;
BUG_ON(!section);
while (section->iov_len < sec_len) {
BUG_ON(section->iov_base == NULL);
left = sec_len - section->iov_len;
ret = ceph_tcp_recvmsg(con->sock, (char *)section->iov_base +
section->iov_len, left);
if (ret <= 0)
return ret;
section->iov_len += ret;
}
if (section->iov_len == sec_len)
*crc = crc32c(0, section->iov_base, section->iov_len);
return 1;
}
static int read_partial_msg_data(struct ceph_connection *con)
{
struct ceph_msg *msg = con->in_msg;
struct ceph_msg_data_cursor *cursor = &msg->cursor;
const bool do_datacrc = !con->msgr->nocrc;
struct page *page;
size_t page_offset;
size_t length;
u32 crc = 0;
int ret;
BUG_ON(!msg);
if (list_empty(&msg->data))
return -EIO;
if (do_datacrc)
crc = con->in_data_crc;
while (cursor->resid) {
page = ceph_msg_data_next(&msg->cursor, &page_offset, &length,
NULL);
ret = ceph_tcp_recvpage(con->sock, page, page_offset, length);
if (ret <= 0) {
if (do_datacrc)
con->in_data_crc = crc;
return ret;
}
if (do_datacrc)
crc = ceph_crc32c_page(crc, page, page_offset, ret);
(void) ceph_msg_data_advance(&msg->cursor, (size_t)ret);
}
if (do_datacrc)
con->in_data_crc = crc;
return 1; /* must return > 0 to indicate success */
}
/*
* read (part of) a message.
*/
static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip);
static int read_partial_message(struct ceph_connection *con)
{
struct ceph_msg *m = con->in_msg;
int size;
int end;
int ret;
unsigned int front_len, middle_len, data_len;
bool do_datacrc = !con->msgr->nocrc;
u64 seq;
u32 crc;
dout("read_partial_message con %p msg %p\n", con, m);
/* header */
size = sizeof (con->in_hdr);
end = size;
ret = read_partial(con, end, size, &con->in_hdr);
if (ret <= 0)
return ret;
crc = crc32c(0, &con->in_hdr, offsetof(struct ceph_msg_header, crc));
if (cpu_to_le32(crc) != con->in_hdr.crc) {
pr_err("read_partial_message bad hdr "
" crc %u != expected %u\n",
crc, con->in_hdr.crc);
return -EBADMSG;
}
front_len = le32_to_cpu(con->in_hdr.front_len);
if (front_len > CEPH_MSG_MAX_FRONT_LEN)
return -EIO;
middle_len = le32_to_cpu(con->in_hdr.middle_len);
if (middle_len > CEPH_MSG_MAX_MIDDLE_LEN)
return -EIO;
data_len = le32_to_cpu(con->in_hdr.data_len);
if (data_len > CEPH_MSG_MAX_DATA_LEN)
return -EIO;
/* verify seq# */
seq = le64_to_cpu(con->in_hdr.seq);
if ((s64)seq - (s64)con->in_seq < 1) {
pr_info("skipping %s%lld %s seq %lld expected %lld\n",
ENTITY_NAME(con->peer_name),
ceph_pr_addr(&con->peer_addr.in_addr),
seq, con->in_seq + 1);
con->in_base_pos = -front_len - middle_len - data_len -
sizeof(m->footer);
con->in_tag = CEPH_MSGR_TAG_READY;
return 0;
} else if ((s64)seq - (s64)con->in_seq > 1) {
pr_err("read_partial_message bad seq %lld expected %lld\n",
seq, con->in_seq + 1);
con->error_msg = "bad message sequence # for incoming message";
return -EBADMSG;
}
/* allocate message? */
if (!con->in_msg) {
int skip = 0;
dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
front_len, data_len);
ret = ceph_con_in_msg_alloc(con, &skip);
if (ret < 0)
return ret;
BUG_ON(!con->in_msg ^ skip);
if (con->in_msg && data_len > con->in_msg->data_length) {
pr_warning("%s skipping long message (%u > %zd)\n",
__func__, data_len, con->in_msg->data_length);
ceph_msg_put(con->in_msg);
con->in_msg = NULL;
skip = 1;
}
if (skip) {
/* skip this message */
dout("alloc_msg said skip message\n");
con->in_base_pos = -front_len - middle_len - data_len -
sizeof(m->footer);
con->in_tag = CEPH_MSGR_TAG_READY;
con->in_seq++;
return 0;
}
BUG_ON(!con->in_msg);
BUG_ON(con->in_msg->con != con);
m = con->in_msg;
m->front.iov_len = 0; /* haven't read it yet */
if (m->middle)
m->middle->vec.iov_len = 0;
/* prepare for data payload, if any */
if (data_len)
prepare_message_data(con->in_msg, data_len);
}
/* front */
ret = read_partial_message_section(con, &m->front, front_len,
&con->in_front_crc);
if (ret <= 0)
return ret;
/* middle */
if (m->middle) {
ret = read_partial_message_section(con, &m->middle->vec,
middle_len,
&con->in_middle_crc);
if (ret <= 0)
return ret;
}
/* (page) data */
if (data_len) {
ret = read_partial_msg_data(con);
if (ret <= 0)
return ret;
}
/* footer */
size = sizeof (m->footer);
end += size;
ret = read_partial(con, end, size, &m->footer);
if (ret <= 0)
return ret;
dout("read_partial_message got msg %p %d (%u) + %d (%u) + %d (%u)\n",
m, front_len, m->footer.front_crc, middle_len,
m->footer.middle_crc, data_len, m->footer.data_crc);
/* crc ok? */
if (con->in_front_crc != le32_to_cpu(m->footer.front_crc)) {
pr_err("read_partial_message %p front crc %u != exp. %u\n",
m, con->in_front_crc, m->footer.front_crc);
return -EBADMSG;
}
if (con->in_middle_crc != le32_to_cpu(m->footer.middle_crc)) {
pr_err("read_partial_message %p middle crc %u != exp %u\n",
m, con->in_middle_crc, m->footer.middle_crc);
return -EBADMSG;
}
if (do_datacrc &&
(m->footer.flags & CEPH_MSG_FOOTER_NOCRC) == 0 &&
con->in_data_crc != le32_to_cpu(m->footer.data_crc)) {
pr_err("read_partial_message %p data crc %u != exp. %u\n", m,
con->in_data_crc, le32_to_cpu(m->footer.data_crc));
return -EBADMSG;
}
return 1; /* done! */
}
/*
* 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.
*/
static void process_message(struct ceph_connection *con)
{
struct ceph_msg *msg;
BUG_ON(con->in_msg->con != con);
con->in_msg->con = NULL;
msg = con->in_msg;
con->in_msg = NULL;
con->ops->put(con);
/* 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 (%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.data_len),
con->in_front_crc, con->in_middle_crc, con->in_data_crc);
con->ops->dispatch(con, msg);
mutex_lock(&con->mutex);
}
/*
* Write something to the socket. Called in a worker thread when the
* socket appears to be writeable and we have something ready to send.
*/
static int try_write(struct ceph_connection *con)
{
int ret = 1;
dout("try_write start %p state %lu\n", con, con->state);
more:
dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes);
/* open the socket first? */
if (con->state == CON_STATE_PREOPEN) {
BUG_ON(con->sock);
con->state = CON_STATE_CONNECTING;
con_out_kvec_reset(con);
prepare_write_banner(con);
prepare_read_banner(con);
BUG_ON(con->in_msg);
con->in_tag = CEPH_MSGR_TAG_READY;
dout("try_write initiating connect on %p new state %lu\n",
con, con->state);
ret = ceph_tcp_connect(con);
if (ret < 0) {
con->error_msg = "connect error";
goto out;
}
}
more_kvec:
/* kvec data queued? */
if (con->out_skip) {
ret = write_partial_skip(con);
if (ret <= 0)
goto out;
}
if (con->out_kvec_left) {
ret = write_partial_kvec(con);
if (ret <= 0)
goto out;
}
/* msg pages? */
if (con->out_msg) {
if (con->out_msg_done) {
ceph_msg_put(con->out_msg);
con->out_msg = NULL; /* we're done with this one */
goto do_next;
}
ret = write_partial_message_data(con);
if (ret == 1)
goto more_kvec; /* we need to send the footer, too! */
if (ret == 0)
goto out;
if (ret < 0) {
dout("try_write write_partial_message_data err %d\n",
ret);
goto out;
}
}
do_next:
if (con->state == CON_STATE_OPEN) {
/* is anything else pending? */
if (!list_empty(&con->out_queue)) {
prepare_write_message(con);
goto more;
}
if (con->in_seq > con->in_seq_acked) {
prepare_write_ack(con);
goto more;
}
if (con_flag_test_and_clear(con, CON_FLAG_KEEPALIVE_PENDING)) {
prepare_write_keepalive(con);
goto more;
}
}
/* Nothing to do! */
con_flag_clear(con, CON_FLAG_WRITE_PENDING);
dout("try_write nothing else to write.\n");
ret = 0;
out:
dout("try_write done on %p ret %d\n", con, ret);
return ret;
}
/*
* Read what we can from the socket.
*/
static int try_read(struct ceph_connection *con)
{
int ret = -1;
more:
dout("try_read start on %p state %lu\n", con, con->state);
if (con->state != CON_STATE_CONNECTING &&
con->state != CON_STATE_NEGOTIATING &&
con->state != CON_STATE_OPEN)
return 0;
BUG_ON(!con->sock);
dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag,
con->in_base_pos);
if (con->state == CON_STATE_CONNECTING) {
dout("try_read connecting\n");
ret = read_partial_banner(con);
if (ret <= 0)
goto out;
ret = process_banner(con);
if (ret < 0)
goto out;
con->state = CON_STATE_NEGOTIATING;
/*
* Received banner is good, exchange connection info.
* Do not reset out_kvec, as sending our banner raced
* with receiving peer banner after connect completed.
*/
ret = prepare_write_connect(con);
if (ret < 0)
goto out;
prepare_read_connect(con);
/* Send connection info before awaiting response */
goto out;
}
if (con->state == CON_STATE_NEGOTIATING) {
dout("try_read negotiating\n");
ret = read_partial_connect(con);
if (ret <= 0)
goto out;
ret = process_connect(con);
if (ret < 0)
goto out;
goto more;
}
WARN_ON(con->state != CON_STATE_OPEN);
if (con->in_base_pos < 0) {
/*
* skipping + discarding content.
*
* FIXME: there must be a better way to do this!
*/
static char buf[SKIP_BUF_SIZE];
int skip = min((int) sizeof (buf), -con->in_base_pos);
dout("skipping %d / %d bytes\n", skip, -con->in_base_pos);
ret = ceph_tcp_recvmsg(con->sock, buf, skip);
if (ret <= 0)
goto out;
con->in_base_pos += ret;
if (con->in_base_pos)
goto more;
}
if (con->in_tag == CEPH_MSGR_TAG_READY) {
/*
* what's next?
*/
ret = ceph_tcp_recvmsg(con->sock, &con->in_tag, 1);
if (ret <= 0)
goto out;
dout("try_read got tag %d\n", (int)con->in_tag);
switch (con->in_tag) {
case CEPH_MSGR_TAG_MSG:
prepare_read_message(con);
break;
case CEPH_MSGR_TAG_ACK:
prepare_read_ack(con);
break;
case CEPH_MSGR_TAG_CLOSE:
con_close_socket(con);
con->state = CON_STATE_CLOSED;
goto out;
default:
goto bad_tag;
}
}
if (con->in_tag == CEPH_MSGR_TAG_MSG) {
ret = read_partial_message(con);
if (ret <= 0) {
switch (ret) {
case -EBADMSG:
con->error_msg = "bad crc";
ret = -EIO;
break;
case -EIO:
con->error_msg = "io error";
break;
}
goto out;
}
if (con->in_tag == CEPH_MSGR_TAG_READY)
goto more;
process_message(con);
if (con->state == CON_STATE_OPEN)
prepare_read_tag(con);
goto more;
}
if (con->in_tag == CEPH_MSGR_TAG_ACK ||
con->in_tag == CEPH_MSGR_TAG_SEQ) {
/*
* the final handshake seq exchange is semantically
* equivalent to an ACK
*/
ret = read_partial_ack(con);
if (ret <= 0)
goto out;
process_ack(con);
goto more;
}
out:
dout("try_read done on %p ret %d\n", con, ret);
return ret;
bad_tag:
pr_err("try_read bad con->in_tag = %d\n", (int)con->in_tag);
con->error_msg = "protocol error, garbage tag";
ret = -1;
goto out;
}
/*
* 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 (!queue_delayed_work(ceph_msgr_wq, &con->work, delay)) {
dout("%s %p - already queued\n", __func__, con);
con->ops->put(con);
return -EBUSY;
}
dout("%s %p %lu\n", __func__, con, delay);
return 0;
}
static void queue_con(struct ceph_connection *con)
{
(void) queue_con_delay(con, 0);
}
static bool con_sock_closed(struct ceph_connection *con)
{
if (!con_flag_test_and_clear(con, CON_FLAG_SOCK_CLOSED))
return false;
#define CASE(x) \
case CON_STATE_ ## x: \
con->error_msg = "socket closed (con state " #x ")"; \
break;
switch (con->state) {
CASE(CLOSED);
CASE(PREOPEN);
CASE(CONNECTING);
CASE(NEGOTIATING);
CASE(OPEN);
CASE(STANDBY);
default:
pr_warning("%s con %p unrecognized state %lu\n",
__func__, con, con->state);
con->error_msg = "unrecognized con state";
BUG();
break;
}
#undef CASE
return true;
}
static bool con_backoff(struct ceph_connection *con)
{
int ret;
if (!con_flag_test_and_clear(con, CON_FLAG_BACKOFF))
return false;
ret = queue_con_delay(con, round_jiffies_relative(con->delay));
if (ret) {
dout("%s: con %p FAILED to back off %lu\n", __func__,
con, con->delay);
BUG_ON(ret == -ENOENT);
con_flag_set(con, CON_FLAG_BACKOFF);
}
return true;
}
/* Finish fault handling; con->mutex must *not* be held here */
static void con_fault_finish(struct ceph_connection *con)
{
/*
* in case we faulted due to authentication, invalidate our
* current tickets so that we can get new ones.
*/
if (con->auth_retry && con->ops->invalidate_authorizer) {
dout("calling invalidate_authorizer()\n");
con->ops->invalidate_authorizer(con);
}
if (con->ops->fault)
con->ops->fault(con);
}
/*
* Do some work on a connection. Drop a connection ref when we're done.
*/
static void con_work(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 == CON_STATE_STANDBY) {
dout("%s: con %p STANDBY\n", __func__, con);
break;
}
if (con->state == CON_STATE_CLOSED) {
dout("%s: con %p CLOSED\n", __func__, con);
BUG_ON(con->sock);
break;
}
if (con->state == CON_STATE_PREOPEN) {
dout("%s: con %p PREOPEN\n", __func__, con);
BUG_ON(con->sock);
}
ret = try_read(con);
if (ret < 0) {
if (ret == -EAGAIN)
continue;
con->error_msg = "socket error on read";
fault = true;
break;
}
ret = try_write(con);
if (ret < 0) {
if (ret == -EAGAIN)
continue;
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)
{
pr_warning("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
ceph_pr_addr(&con->peer_addr.in_addr), con->error_msg);
dout("fault %p state %lu to peer %s\n",
con, con->state, ceph_pr_addr(&con->peer_addr.in_addr));
WARN_ON(con->state != CON_STATE_CONNECTING &&
con->state != CON_STATE_NEGOTIATING &&
con->state != CON_STATE_OPEN);
con_close_socket(con);
if (con_flag_test(con, CON_FLAG_LOSSYTX)) {
dout("fault on LOSSYTX channel, marking CLOSED\n");
con->state = CON_STATE_CLOSED;
return;
}
if (con->in_msg) {
BUG_ON(con->in_msg->con != con);
con->in_msg->con = NULL;
ceph_msg_put(con->in_msg);
con->in_msg = NULL;
con->ops->put(con);
}
/* 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) &&
!con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING)) {
dout("fault %p setting STANDBY clearing WRITE_PENDING\n", con);
con_flag_clear(con, CON_FLAG_WRITE_PENDING);
con->state = CON_STATE_STANDBY;
} else {
/* retry after a delay. */
con->state = CON_STATE_PREOPEN;
if (con->delay == 0)
con->delay = BASE_DELAY_INTERVAL;
else if (con->delay < MAX_DELAY_INTERVAL)
con->delay *= 2;
con_flag_set(con, CON_FLAG_BACKOFF);
queue_con(con);
}
}
/*
* initialize a new messenger instance
*/
void ceph_messenger_init(struct ceph_messenger *msgr,
struct ceph_entity_addr *myaddr,
u64 supported_features,
u64 required_features,
bool nocrc)
{
msgr->supported_features = supported_features;
msgr->required_features = required_features;
spin_lock_init(&msgr->global_seq_lock);
if (myaddr)
msgr->inst.addr = *myaddr;
/* select a random nonce */
msgr->inst.addr.type = 0;
get_random_bytes(&msgr->inst.addr.nonce, sizeof(msgr->inst.addr.nonce));
encode_my_addr(msgr);
msgr->nocrc = nocrc;
atomic_set(&msgr->stopping, 0);
dout("%s %p\n", __func__, msgr);
}
EXPORT_SYMBOL(ceph_messenger_init);
static void clear_standby(struct ceph_connection *con)
{
/* come back from STANDBY? */
if (con->state == CON_STATE_STANDBY) {
dout("clear_standby %p and ++connect_seq\n", con);
con->state = CON_STATE_PREOPEN;
con->connect_seq++;
WARN_ON(con_flag_test(con, CON_FLAG_WRITE_PENDING));
WARN_ON(con_flag_test(con, CON_FLAG_KEEPALIVE_PENDING));
}
}
/*
* Queue up an outgoing message on the given connection.
*/
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 == CON_STATE_CLOSED) {
dout("con_send %p closed, dropping %p\n", con, msg);
ceph_msg_put(msg);
mutex_unlock(&con->mutex);
return;
}
BUG_ON(msg->con != NULL);
msg->con = con->ops->get(con);
BUG_ON(msg->con == NULL);
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 (con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
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)
return; /* Message not in our possession */
mutex_lock(&con->mutex);
if (!list_empty(&msg->list_head)) {
dout("%s %p msg %p - was on queue\n", __func__, con, msg);
list_del_init(&msg->list_head);
BUG_ON(msg->con == NULL);
msg->con->ops->put(msg->con);
msg->con = NULL;
msg->hdr.seq = 0;
ceph_msg_put(msg);
}
if (con->out_msg == msg) {
dout("%s %p msg %p - was sending\n", __func__, con, msg);
con->out_msg = NULL;
if (con->out_kvec_is_msg) {
con->out_skip = con->out_kvec_bytes;
con->out_kvec_is_msg = false;
}
msg->hdr.seq = 0;
ceph_msg_put(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;
BUG_ON(msg == NULL);
if (!msg->con) {
dout("%s msg %p null con\n", __func__, msg);
return; /* Message not in our possession */
}
con = msg->con;
mutex_lock(&con->mutex);
if (con->in_msg == msg) {
unsigned int front_len = le32_to_cpu(con->in_hdr.front_len);
unsigned int middle_len = le32_to_cpu(con->in_hdr.middle_len);
unsigned int data_len = le32_to_cpu(con->in_hdr.data_len);
/* skip rest of message */
dout("%s %p msg %p revoked\n", __func__, con, msg);
con->in_base_pos = con->in_base_pos -
sizeof(struct ceph_msg_header) -
front_len -
middle_len -
data_len -
sizeof(struct ceph_msg_footer);
ceph_msg_put(con->in_msg);
con->in_msg = NULL;
con->in_tag = CEPH_MSGR_TAG_READY;
con->in_seq++;
} else {
dout("%s %p in_msg %p msg %p no-op\n",
__func__, con, con->in_msg, 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);
mutex_unlock(&con->mutex);
if (con_flag_test_and_set(con, CON_FLAG_KEEPALIVE_PENDING) == 0 &&
con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
queue_con(con);
}
EXPORT_SYMBOL(ceph_con_keepalive);
static struct ceph_msg_data *ceph_msg_data_create(enum ceph_msg_data_type type)
{
struct ceph_msg_data *data;
if (WARN_ON(!ceph_msg_data_type_valid(type)))
return NULL;
data = kmem_cache_zalloc(ceph_msg_data_cache, GFP_NOFS);
if (data)
data->type = type;
INIT_LIST_HEAD(&data->links);
return data;
}
static void ceph_msg_data_destroy(struct ceph_msg_data *data)
{
if (!data)
return;
WARN_ON(!list_empty(&data->links));
if (data->type == CEPH_MSG_DATA_PAGELIST) {
ceph_pagelist_release(data->pagelist);
kfree(data->pagelist);
}
kmem_cache_free(ceph_msg_data_cache, data);
}
void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,
size_t length, size_t alignment)
{
struct ceph_msg_data *data;
BUG_ON(!pages);
BUG_ON(!length);
data = ceph_msg_data_create(CEPH_MSG_DATA_PAGES);
BUG_ON(!data);
data->pages = pages;
data->length = length;
data->alignment = alignment & ~PAGE_MASK;
list_add_tail(&data->links, &msg->data);
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_create(CEPH_MSG_DATA_PAGELIST);
BUG_ON(!data);
data->pagelist = pagelist;
list_add_tail(&data->links, &msg->data);
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 bio *bio,
size_t length)
{
struct ceph_msg_data *data;
BUG_ON(!bio);
data = ceph_msg_data_create(CEPH_MSG_DATA_BIO);
BUG_ON(!data);
data->bio = bio;
data->bio_length = length;
list_add_tail(&data->links, &msg->data);
msg->data_length += length;
}
EXPORT_SYMBOL(ceph_msg_data_add_bio);
#endif /* CONFIG_BLOCK */
/*
* construct a new message with given type, size
* the new msg has a ref count of 1.
*/
struct ceph_msg *ceph_msg_new(int type, int front_len, 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);
INIT_LIST_HEAD(&m->data);
/* front */
if (front_len) {
m->front.iov_base = ceph_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;
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_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
*/
static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
{
struct ceph_msg_header *hdr = &con->in_hdr;
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 != CON_STATE_OPEN) {
if (msg)
ceph_msg_put(msg);
return -EAGAIN;
}
if (msg) {
BUG_ON(*skip);
con->in_msg = msg;
con->in_msg->con = con->ops->get(con);
BUG_ON(con->in_msg->con == NULL);
} 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, &con->in_hdr, sizeof(con->in_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;
}
/*
* Free a generically kmalloc'd message.
*/
void ceph_msg_kfree(struct ceph_msg *m)
{
dout("msg_kfree %p\n", m);
ceph_kvfree(m->front.iov_base);
kmem_cache_free(ceph_msg_cache, m);
}
/*
* Drop a msg ref. Destroy as needed.
*/
void ceph_msg_last_put(struct kref *kref)
{
struct ceph_msg *m = container_of(kref, struct ceph_msg, kref);
LIST_HEAD(data);
struct list_head *links;
struct list_head *next;
dout("ceph_msg_put last one on %p\n", m);
WARN_ON(!list_empty(&m->list_head));
/* drop middle, data, if any */
if (m->middle) {
ceph_buffer_put(m->middle);
m->middle = NULL;
}
list_splice_init(&m->data, &data);
list_for_each_safe(links, next, &data) {
struct ceph_msg_data *data;
data = list_entry(links, struct ceph_msg_data, links);
list_del_init(links);
ceph_msg_data_destroy(data);
}
m->data_length = 0;
if (m->pool)
ceph_msgpool_put(m->pool, m);
else
ceph_msg_kfree(m);
}
EXPORT_SYMBOL(ceph_msg_last_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);