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linux-stable-rt/net/sunrpc/xprtsock.c

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32 KiB
C
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/*
* linux/net/sunrpc/xprtsock.c
*
* Client-side transport implementation for sockets.
*
* TCP callback races fixes (C) 1998 Red Hat Software <alan@redhat.com>
* TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com>
* TCP NFS related read + write fixes
* (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
*
* Rewrite of larges part of the code in order to stabilize TCP stuff.
* Fix behaviour when socket buffer is full.
* (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
*
* IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/capability.h>
#include <linux/sched.h>
#include <linux/pagemap.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/net.h>
#include <linux/mm.h>
#include <linux/udp.h>
#include <linux/tcp.h>
#include <linux/sunrpc/clnt.h>
#include <linux/file.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <net/udp.h>
#include <net/tcp.h>
/*
* xprtsock tunables
*/
unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
/*
* How many times to try sending a request on a socket before waiting
* for the socket buffer to clear.
*/
#define XS_SENDMSG_RETRY (10U)
/*
* Time out for an RPC UDP socket connect. UDP socket connects are
* synchronous, but we set a timeout anyway in case of resource
* exhaustion on the local host.
*/
#define XS_UDP_CONN_TO (5U * HZ)
/*
* Wait duration for an RPC TCP connection to be established. Solaris
* NFS over TCP uses 60 seconds, for example, which is in line with how
* long a server takes to reboot.
*/
#define XS_TCP_CONN_TO (60U * HZ)
/*
* Wait duration for a reply from the RPC portmapper.
*/
#define XS_BIND_TO (60U * HZ)
/*
* Delay if a UDP socket connect error occurs. This is most likely some
* kind of resource problem on the local host.
*/
#define XS_UDP_REEST_TO (2U * HZ)
/*
* The reestablish timeout allows clients to delay for a bit before attempting
* to reconnect to a server that just dropped our connection.
*
* We implement an exponential backoff when trying to reestablish a TCP
* transport connection with the server. Some servers like to drop a TCP
* connection when they are overworked, so we start with a short timeout and
* increase over time if the server is down or not responding.
*/
#define XS_TCP_INIT_REEST_TO (3U * HZ)
#define XS_TCP_MAX_REEST_TO (5U * 60 * HZ)
/*
* TCP idle timeout; client drops the transport socket if it is idle
* for this long. Note that we also timeout UDP sockets to prevent
* holding port numbers when there is no RPC traffic.
*/
#define XS_IDLE_DISC_TO (5U * 60 * HZ)
#ifdef RPC_DEBUG
# undef RPC_DEBUG_DATA
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
#ifdef RPC_DEBUG_DATA
static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
{
u8 *buf = (u8 *) packet;
int j;
dprintk("RPC: %s\n", msg);
for (j = 0; j < count && j < 128; j += 4) {
if (!(j & 31)) {
if (j)
dprintk("\n");
dprintk("0x%04x ", j);
}
dprintk("%02x%02x%02x%02x ",
buf[j], buf[j+1], buf[j+2], buf[j+3]);
}
dprintk("\n");
}
#else
static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
{
/* NOP */
}
#endif
#define XS_SENDMSG_FLAGS (MSG_DONTWAIT | MSG_NOSIGNAL)
static inline int xs_send_head(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, unsigned int len)
{
struct kvec iov = {
.iov_base = xdr->head[0].iov_base + base,
.iov_len = len - base,
};
struct msghdr msg = {
.msg_name = addr,
.msg_namelen = addrlen,
.msg_flags = XS_SENDMSG_FLAGS,
};
if (xdr->len > len)
msg.msg_flags |= MSG_MORE;
if (likely(iov.iov_len))
return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
return kernel_sendmsg(sock, &msg, NULL, 0, 0);
}
static int xs_send_tail(struct socket *sock, struct xdr_buf *xdr, unsigned int base, unsigned int len)
{
struct kvec iov = {
.iov_base = xdr->tail[0].iov_base + base,
.iov_len = len - base,
};
struct msghdr msg = {
.msg_flags = XS_SENDMSG_FLAGS,
};
return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
}
/**
* xs_sendpages - write pages directly to a socket
* @sock: socket to send on
* @addr: UDP only -- address of destination
* @addrlen: UDP only -- length of destination address
* @xdr: buffer containing this request
* @base: starting position in the buffer
*
*/
static inline int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
{
struct page **ppage = xdr->pages;
unsigned int len, pglen = xdr->page_len;
int err, ret = 0;
ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
if (unlikely(!sock))
return -ENOTCONN;
clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
len = xdr->head[0].iov_len;
if (base < len || (addr != NULL && base == 0)) {
err = xs_send_head(sock, addr, addrlen, xdr, base, len);
if (ret == 0)
ret = err;
else if (err > 0)
ret += err;
if (err != (len - base))
goto out;
base = 0;
} else
base -= len;
if (unlikely(pglen == 0))
goto copy_tail;
if (unlikely(base >= pglen)) {
base -= pglen;
goto copy_tail;
}
if (base || xdr->page_base) {
pglen -= base;
base += xdr->page_base;
ppage += base >> PAGE_CACHE_SHIFT;
base &= ~PAGE_CACHE_MASK;
}
sendpage = sock->ops->sendpage ? : sock_no_sendpage;
do {
int flags = XS_SENDMSG_FLAGS;
len = PAGE_CACHE_SIZE;
if (base)
len -= base;
if (pglen < len)
len = pglen;
if (pglen != len || xdr->tail[0].iov_len != 0)
flags |= MSG_MORE;
/* Hmm... We might be dealing with highmem pages */
if (PageHighMem(*ppage))
sendpage = sock_no_sendpage;
err = sendpage(sock, *ppage, base, len, flags);
if (ret == 0)
ret = err;
else if (err > 0)
ret += err;
if (err != len)
goto out;
base = 0;
ppage++;
} while ((pglen -= len) != 0);
copy_tail:
len = xdr->tail[0].iov_len;
if (base < len) {
err = xs_send_tail(sock, xdr, base, len);
if (ret == 0)
ret = err;
else if (err > 0)
ret += err;
}
out:
return ret;
}
/**
* xs_nospace - place task on wait queue if transmit was incomplete
* @task: task to put to sleep
*
*/
static void xs_nospace(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_xprt;
dprintk("RPC: %4d xmit incomplete (%u left of %u)\n",
task->tk_pid, req->rq_slen - req->rq_bytes_sent,
req->rq_slen);
if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
/* Protect against races with write_space */
spin_lock_bh(&xprt->transport_lock);
/* Don't race with disconnect */
if (!xprt_connected(xprt))
task->tk_status = -ENOTCONN;
else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags))
xprt_wait_for_buffer_space(task);
spin_unlock_bh(&xprt->transport_lock);
} else
/* Keep holding the socket if it is blocked */
rpc_delay(task, HZ>>4);
}
/**
* xs_udp_send_request - write an RPC request to a UDP socket
* @task: address of RPC task that manages the state of an RPC request
*
* Return values:
* 0: The request has been sent
* EAGAIN: The socket was blocked, please call again later to
* complete the request
* ENOTCONN: Caller needs to invoke connect logic then call again
* other: Some other error occured, the request was not sent
*/
static int xs_udp_send_request(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_xprt;
struct xdr_buf *xdr = &req->rq_snd_buf;
int status;
xs_pktdump("packet data:",
req->rq_svec->iov_base,
req->rq_svec->iov_len);
req->rq_xtime = jiffies;
status = xs_sendpages(xprt->sock, (struct sockaddr *) &xprt->addr,
sizeof(xprt->addr), xdr, req->rq_bytes_sent);
dprintk("RPC: xs_udp_send_request(%u) = %d\n",
xdr->len - req->rq_bytes_sent, status);
if (likely(status >= (int) req->rq_slen))
return 0;
/* Still some bytes left; set up for a retry later. */
if (status > 0)
status = -EAGAIN;
switch (status) {
case -ENETUNREACH:
case -EPIPE:
case -ECONNREFUSED:
/* When the server has died, an ICMP port unreachable message
* prompts ECONNREFUSED. */
break;
case -EAGAIN:
xs_nospace(task);
break;
default:
dprintk("RPC: sendmsg returned unrecognized error %d\n",
-status);
break;
}
return status;
}
static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
{
u32 reclen = buf->len - sizeof(rpc_fraghdr);
rpc_fraghdr *base = buf->head[0].iov_base;
*base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
}
/**
* xs_tcp_send_request - write an RPC request to a TCP socket
* @task: address of RPC task that manages the state of an RPC request
*
* Return values:
* 0: The request has been sent
* EAGAIN: The socket was blocked, please call again later to
* complete the request
* ENOTCONN: Caller needs to invoke connect logic then call again
* other: Some other error occured, the request was not sent
*
* XXX: In the case of soft timeouts, should we eventually give up
* if sendmsg is not able to make progress?
*/
static int xs_tcp_send_request(struct rpc_task *task)
{
struct rpc_rqst *req = task->tk_rqstp;
struct rpc_xprt *xprt = req->rq_xprt;
struct xdr_buf *xdr = &req->rq_snd_buf;
int status, retry = 0;
xs_encode_tcp_record_marker(&req->rq_snd_buf);
xs_pktdump("packet data:",
req->rq_svec->iov_base,
req->rq_svec->iov_len);
/* Continue transmitting the packet/record. We must be careful
* to cope with writespace callbacks arriving _after_ we have
* called sendmsg(). */
while (1) {
req->rq_xtime = jiffies;
status = xs_sendpages(xprt->sock, NULL, 0, xdr,
req->rq_bytes_sent);
dprintk("RPC: xs_tcp_send_request(%u) = %d\n",
xdr->len - req->rq_bytes_sent, status);
if (unlikely(status < 0))
break;
/* If we've sent the entire packet, immediately
* reset the count of bytes sent. */
req->rq_bytes_sent += status;
if (likely(req->rq_bytes_sent >= req->rq_slen)) {
req->rq_bytes_sent = 0;
return 0;
}
status = -EAGAIN;
if (retry++ > XS_SENDMSG_RETRY)
break;
}
switch (status) {
case -EAGAIN:
xs_nospace(task);
break;
case -ECONNREFUSED:
case -ECONNRESET:
case -ENOTCONN:
case -EPIPE:
status = -ENOTCONN;
break;
default:
dprintk("RPC: sendmsg returned unrecognized error %d\n",
-status);
xprt_disconnect(xprt);
break;
}
return status;
}
/**
* xs_close - close a socket
* @xprt: transport
*
* This is used when all requests are complete; ie, no DRC state remains
* on the server we want to save.
*/
static void xs_close(struct rpc_xprt *xprt)
{
struct socket *sock = xprt->sock;
struct sock *sk = xprt->inet;
if (!sk)
return;
dprintk("RPC: xs_close xprt %p\n", xprt);
write_lock_bh(&sk->sk_callback_lock);
xprt->inet = NULL;
xprt->sock = NULL;
sk->sk_user_data = NULL;
sk->sk_data_ready = xprt->old_data_ready;
sk->sk_state_change = xprt->old_state_change;
sk->sk_write_space = xprt->old_write_space;
write_unlock_bh(&sk->sk_callback_lock);
sk->sk_no_check = 0;
sock_release(sock);
}
/**
* xs_destroy - prepare to shutdown a transport
* @xprt: doomed transport
*
*/
static void xs_destroy(struct rpc_xprt *xprt)
{
dprintk("RPC: xs_destroy xprt %p\n", xprt);
cancel_delayed_work(&xprt->connect_worker);
flush_scheduled_work();
xprt_disconnect(xprt);
xs_close(xprt);
kfree(xprt->slot);
}
static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
{
return (struct rpc_xprt *) sk->sk_user_data;
}
/**
* xs_udp_data_ready - "data ready" callback for UDP sockets
* @sk: socket with data to read
* @len: how much data to read
*
*/
static void xs_udp_data_ready(struct sock *sk, int len)
{
struct rpc_task *task;
struct rpc_xprt *xprt;
struct rpc_rqst *rovr;
struct sk_buff *skb;
int err, repsize, copied;
u32 _xid, *xp;
read_lock(&sk->sk_callback_lock);
dprintk("RPC: xs_udp_data_ready...\n");
if (!(xprt = xprt_from_sock(sk)))
goto out;
if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
goto out;
if (xprt->shutdown)
goto dropit;
repsize = skb->len - sizeof(struct udphdr);
if (repsize < 4) {
dprintk("RPC: impossible RPC reply size %d!\n", repsize);
goto dropit;
}
/* Copy the XID from the skb... */
xp = skb_header_pointer(skb, sizeof(struct udphdr),
sizeof(_xid), &_xid);
if (xp == NULL)
goto dropit;
/* Look up and lock the request corresponding to the given XID */
spin_lock(&xprt->transport_lock);
rovr = xprt_lookup_rqst(xprt, *xp);
if (!rovr)
goto out_unlock;
task = rovr->rq_task;
if ((copied = rovr->rq_private_buf.buflen) > repsize)
copied = repsize;
/* Suck it into the iovec, verify checksum if not done by hw. */
if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
goto out_unlock;
/* Something worked... */
dst_confirm(skb->dst);
xprt_adjust_cwnd(task, copied);
xprt_update_rtt(task);
xprt_complete_rqst(task, copied);
out_unlock:
spin_unlock(&xprt->transport_lock);
dropit:
skb_free_datagram(sk, skb);
out:
read_unlock(&sk->sk_callback_lock);
}
static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
{
if (len > desc->count)
len = desc->count;
if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
dprintk("RPC: failed to copy %zu bytes from skb. %zu bytes remain\n",
len, desc->count);
return 0;
}
desc->offset += len;
desc->count -= len;
dprintk("RPC: copied %zu bytes from skb. %zu bytes remain\n",
len, desc->count);
return len;
}
static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
{
size_t len, used;
char *p;
p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset;
len = sizeof(xprt->tcp_recm) - xprt->tcp_offset;
used = xs_tcp_copy_data(desc, p, len);
xprt->tcp_offset += used;
if (used != len)
return;
xprt->tcp_reclen = ntohl(xprt->tcp_recm);
if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
xprt->tcp_flags |= XPRT_LAST_FRAG;
else
xprt->tcp_flags &= ~XPRT_LAST_FRAG;
xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
xprt->tcp_flags &= ~XPRT_COPY_RECM;
xprt->tcp_offset = 0;
/* Sanity check of the record length */
if (unlikely(xprt->tcp_reclen < 4)) {
dprintk("RPC: invalid TCP record fragment length\n");
xprt_disconnect(xprt);
return;
}
dprintk("RPC: reading TCP record fragment of length %d\n",
xprt->tcp_reclen);
}
static void xs_tcp_check_recm(struct rpc_xprt *xprt)
{
dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n",
xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags);
if (xprt->tcp_offset == xprt->tcp_reclen) {
xprt->tcp_flags |= XPRT_COPY_RECM;
xprt->tcp_offset = 0;
if (xprt->tcp_flags & XPRT_LAST_FRAG) {
xprt->tcp_flags &= ~XPRT_COPY_DATA;
xprt->tcp_flags |= XPRT_COPY_XID;
xprt->tcp_copied = 0;
}
}
}
static inline void xs_tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc)
{
size_t len, used;
char *p;
len = sizeof(xprt->tcp_xid) - xprt->tcp_offset;
dprintk("RPC: reading XID (%Zu bytes)\n", len);
p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset;
used = xs_tcp_copy_data(desc, p, len);
xprt->tcp_offset += used;
if (used != len)
return;
xprt->tcp_flags &= ~XPRT_COPY_XID;
xprt->tcp_flags |= XPRT_COPY_DATA;
xprt->tcp_copied = 4;
dprintk("RPC: reading reply for XID %08x\n",
ntohl(xprt->tcp_xid));
xs_tcp_check_recm(xprt);
}
static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
{
struct rpc_rqst *req;
struct xdr_buf *rcvbuf;
size_t len;
ssize_t r;
/* Find and lock the request corresponding to this xid */
spin_lock(&xprt->transport_lock);
req = xprt_lookup_rqst(xprt, xprt->tcp_xid);
if (!req) {
xprt->tcp_flags &= ~XPRT_COPY_DATA;
dprintk("RPC: XID %08x request not found!\n",
ntohl(xprt->tcp_xid));
spin_unlock(&xprt->transport_lock);
return;
}
rcvbuf = &req->rq_private_buf;
len = desc->count;
if (len > xprt->tcp_reclen - xprt->tcp_offset) {
skb_reader_t my_desc;
len = xprt->tcp_reclen - xprt->tcp_offset;
memcpy(&my_desc, desc, sizeof(my_desc));
my_desc.count = len;
r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
&my_desc, xs_tcp_copy_data);
desc->count -= r;
desc->offset += r;
} else
r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
desc, xs_tcp_copy_data);
if (r > 0) {
xprt->tcp_copied += r;
xprt->tcp_offset += r;
}
if (r != len) {
/* Error when copying to the receive buffer,
* usually because we weren't able to allocate
* additional buffer pages. All we can do now
* is turn off XPRT_COPY_DATA, so the request
* will not receive any additional updates,
* and time out.
* Any remaining data from this record will
* be discarded.
*/
xprt->tcp_flags &= ~XPRT_COPY_DATA;
dprintk("RPC: XID %08x truncated request\n",
ntohl(xprt->tcp_xid));
dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
goto out;
}
dprintk("RPC: XID %08x read %Zd bytes\n",
ntohl(xprt->tcp_xid), r);
dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
if (xprt->tcp_copied == req->rq_private_buf.buflen)
xprt->tcp_flags &= ~XPRT_COPY_DATA;
else if (xprt->tcp_offset == xprt->tcp_reclen) {
if (xprt->tcp_flags & XPRT_LAST_FRAG)
xprt->tcp_flags &= ~XPRT_COPY_DATA;
}
out:
if (!(xprt->tcp_flags & XPRT_COPY_DATA))
xprt_complete_rqst(req->rq_task, xprt->tcp_copied);
spin_unlock(&xprt->transport_lock);
xs_tcp_check_recm(xprt);
}
static inline void xs_tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
{
size_t len;
len = xprt->tcp_reclen - xprt->tcp_offset;
if (len > desc->count)
len = desc->count;
desc->count -= len;
desc->offset += len;
xprt->tcp_offset += len;
dprintk("RPC: discarded %Zu bytes\n", len);
xs_tcp_check_recm(xprt);
}
static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
{
struct rpc_xprt *xprt = rd_desc->arg.data;
skb_reader_t desc = {
.skb = skb,
.offset = offset,
.count = len,
.csum = 0
};
dprintk("RPC: xs_tcp_data_recv started\n");
do {
/* Read in a new fragment marker if necessary */
/* Can we ever really expect to get completely empty fragments? */
if (xprt->tcp_flags & XPRT_COPY_RECM) {
xs_tcp_read_fraghdr(xprt, &desc);
continue;
}
/* Read in the xid if necessary */
if (xprt->tcp_flags & XPRT_COPY_XID) {
xs_tcp_read_xid(xprt, &desc);
continue;
}
/* Read in the request data */
if (xprt->tcp_flags & XPRT_COPY_DATA) {
xs_tcp_read_request(xprt, &desc);
continue;
}
/* Skip over any trailing bytes on short reads */
xs_tcp_read_discard(xprt, &desc);
} while (desc.count);
dprintk("RPC: xs_tcp_data_recv done\n");
return len - desc.count;
}
/**
* xs_tcp_data_ready - "data ready" callback for TCP sockets
* @sk: socket with data to read
* @bytes: how much data to read
*
*/
static void xs_tcp_data_ready(struct sock *sk, int bytes)
{
struct rpc_xprt *xprt;
read_descriptor_t rd_desc;
read_lock(&sk->sk_callback_lock);
dprintk("RPC: xs_tcp_data_ready...\n");
if (!(xprt = xprt_from_sock(sk)))
goto out;
if (xprt->shutdown)
goto out;
/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
rd_desc.arg.data = xprt;
rd_desc.count = 65536;
tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
out:
read_unlock(&sk->sk_callback_lock);
}
/**
* xs_tcp_state_change - callback to handle TCP socket state changes
* @sk: socket whose state has changed
*
*/
static void xs_tcp_state_change(struct sock *sk)
{
struct rpc_xprt *xprt;
read_lock(&sk->sk_callback_lock);
if (!(xprt = xprt_from_sock(sk)))
goto out;
dprintk("RPC: xs_tcp_state_change client %p...\n", xprt);
dprintk("RPC: state %x conn %d dead %d zapped %d\n",
sk->sk_state, xprt_connected(xprt),
sock_flag(sk, SOCK_DEAD),
sock_flag(sk, SOCK_ZAPPED));
switch (sk->sk_state) {
case TCP_ESTABLISHED:
spin_lock_bh(&xprt->transport_lock);
if (!xprt_test_and_set_connected(xprt)) {
/* Reset TCP record info */
xprt->tcp_offset = 0;
xprt->tcp_reclen = 0;
xprt->tcp_copied = 0;
xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID;
xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
xprt_wake_pending_tasks(xprt, 0);
}
spin_unlock_bh(&xprt->transport_lock);
break;
case TCP_SYN_SENT:
case TCP_SYN_RECV:
break;
default:
xprt_disconnect(xprt);
break;
}
out:
read_unlock(&sk->sk_callback_lock);
}
/**
* xs_udp_write_space - callback invoked when socket buffer space
* becomes available
* @sk: socket whose state has changed
*
* Called when more output buffer space is available for this socket.
* We try not to wake our writers until they can make "significant"
* progress, otherwise we'll waste resources thrashing kernel_sendmsg
* with a bunch of small requests.
*/
static void xs_udp_write_space(struct sock *sk)
{
read_lock(&sk->sk_callback_lock);
/* from net/core/sock.c:sock_def_write_space */
if (sock_writeable(sk)) {
struct socket *sock;
struct rpc_xprt *xprt;
if (unlikely(!(sock = sk->sk_socket)))
goto out;
if (unlikely(!(xprt = xprt_from_sock(sk))))
goto out;
if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
goto out;
xprt_write_space(xprt);
}
out:
read_unlock(&sk->sk_callback_lock);
}
/**
* xs_tcp_write_space - callback invoked when socket buffer space
* becomes available
* @sk: socket whose state has changed
*
* Called when more output buffer space is available for this socket.
* We try not to wake our writers until they can make "significant"
* progress, otherwise we'll waste resources thrashing kernel_sendmsg
* with a bunch of small requests.
*/
static void xs_tcp_write_space(struct sock *sk)
{
read_lock(&sk->sk_callback_lock);
/* from net/core/stream.c:sk_stream_write_space */
if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
struct socket *sock;
struct rpc_xprt *xprt;
if (unlikely(!(sock = sk->sk_socket)))
goto out;
if (unlikely(!(xprt = xprt_from_sock(sk))))
goto out;
if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
goto out;
xprt_write_space(xprt);
}
out:
read_unlock(&sk->sk_callback_lock);
}
static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
{
struct sock *sk = xprt->inet;
if (xprt->rcvsize) {
sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs * 2;
}
if (xprt->sndsize) {
sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2;
sk->sk_write_space(sk);
}
}
/**
* xs_udp_set_buffer_size - set send and receive limits
* @xprt: generic transport
* @sndsize: requested size of send buffer, in bytes
* @rcvsize: requested size of receive buffer, in bytes
*
* Set socket send and receive buffer size limits.
*/
static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
{
xprt->sndsize = 0;
if (sndsize)
xprt->sndsize = sndsize + 1024;
xprt->rcvsize = 0;
if (rcvsize)
xprt->rcvsize = rcvsize + 1024;
xs_udp_do_set_buffer_size(xprt);
}
/**
* xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
* @task: task that timed out
*
* Adjust the congestion window after a retransmit timeout has occurred.
*/
static void xs_udp_timer(struct rpc_task *task)
{
xprt_adjust_cwnd(task, -ETIMEDOUT);
}
static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
{
struct sockaddr_in myaddr = {
.sin_family = AF_INET,
};
int err;
unsigned short port = xprt->port;
do {
myaddr.sin_port = htons(port);
err = sock->ops->bind(sock, (struct sockaddr *) &myaddr,
sizeof(myaddr));
if (err == 0) {
xprt->port = port;
dprintk("RPC: xs_bindresvport bound to port %u\n",
port);
return 0;
}
if (port <= xprt_min_resvport)
port = xprt_max_resvport;
else
port--;
} while (err == -EADDRINUSE && port != xprt->port);
dprintk("RPC: can't bind to reserved port (%d).\n", -err);
return err;
}
/**
* xs_udp_connect_worker - set up a UDP socket
* @args: RPC transport to connect
*
* Invoked by a work queue tasklet.
*/
static void xs_udp_connect_worker(void *args)
{
struct rpc_xprt *xprt = (struct rpc_xprt *) args;
struct socket *sock = xprt->sock;
int err, status = -EIO;
if (xprt->shutdown || xprt->addr.sin_port == 0)
goto out;
dprintk("RPC: xs_udp_connect_worker for xprt %p\n", xprt);
/* Start by resetting any existing state */
xs_close(xprt);
if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
dprintk("RPC: can't create UDP transport socket (%d).\n", -err);
goto out;
}
if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
sock_release(sock);
goto out;
}
if (!xprt->inet) {
struct sock *sk = sock->sk;
write_lock_bh(&sk->sk_callback_lock);
sk->sk_user_data = xprt;
xprt->old_data_ready = sk->sk_data_ready;
xprt->old_state_change = sk->sk_state_change;
xprt->old_write_space = sk->sk_write_space;
sk->sk_data_ready = xs_udp_data_ready;
sk->sk_write_space = xs_udp_write_space;
sk->sk_no_check = UDP_CSUM_NORCV;
sk->sk_allocation = GFP_ATOMIC;
xprt_set_connected(xprt);
/* Reset to new socket */
xprt->sock = sock;
xprt->inet = sk;
write_unlock_bh(&sk->sk_callback_lock);
}
xs_udp_do_set_buffer_size(xprt);
status = 0;
out:
xprt_wake_pending_tasks(xprt, status);
xprt_clear_connecting(xprt);
}
/*
* We need to preserve the port number so the reply cache on the server can
* find our cached RPC replies when we get around to reconnecting.
*/
static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
{
int result;
struct socket *sock = xprt->sock;
struct sockaddr any;
dprintk("RPC: disconnecting xprt %p to reuse port\n", xprt);
/*
* Disconnect the transport socket by doing a connect operation
* with AF_UNSPEC. This should return immediately...
*/
memset(&any, 0, sizeof(any));
any.sa_family = AF_UNSPEC;
result = sock->ops->connect(sock, &any, sizeof(any), 0);
if (result)
dprintk("RPC: AF_UNSPEC connect return code %d\n",
result);
}
/**
* xs_tcp_connect_worker - connect a TCP socket to a remote endpoint
* @args: RPC transport to connect
*
* Invoked by a work queue tasklet.
*/
static void xs_tcp_connect_worker(void *args)
{
struct rpc_xprt *xprt = (struct rpc_xprt *)args;
struct socket *sock = xprt->sock;
int err, status = -EIO;
if (xprt->shutdown || xprt->addr.sin_port == 0)
goto out;
dprintk("RPC: xs_tcp_connect_worker for xprt %p\n", xprt);
if (!xprt->sock) {
/* start from scratch */
if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
dprintk("RPC: can't create TCP transport socket (%d).\n", -err);
goto out;
}
if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
sock_release(sock);
goto out;
}
} else
/* "close" the socket, preserving the local port */
xs_tcp_reuse_connection(xprt);
if (!xprt->inet) {
struct sock *sk = sock->sk;
write_lock_bh(&sk->sk_callback_lock);
sk->sk_user_data = xprt;
xprt->old_data_ready = sk->sk_data_ready;
xprt->old_state_change = sk->sk_state_change;
xprt->old_write_space = sk->sk_write_space;
sk->sk_data_ready = xs_tcp_data_ready;
sk->sk_state_change = xs_tcp_state_change;
sk->sk_write_space = xs_tcp_write_space;
sk->sk_allocation = GFP_ATOMIC;
/* socket options */
sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
sock_reset_flag(sk, SOCK_LINGER);
tcp_sk(sk)->linger2 = 0;
tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
xprt_clear_connected(xprt);
/* Reset to new socket */
xprt->sock = sock;
xprt->inet = sk;
write_unlock_bh(&sk->sk_callback_lock);
}
/* Tell the socket layer to start connecting... */
status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr,
sizeof(xprt->addr), O_NONBLOCK);
dprintk("RPC: %p connect status %d connected %d sock state %d\n",
xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
if (status < 0) {
switch (status) {
case -EINPROGRESS:
case -EALREADY:
goto out_clear;
case -ECONNREFUSED:
case -ECONNRESET:
/* retry with existing socket, after a delay */
break;
default:
/* get rid of existing socket, and retry */
xs_close(xprt);
break;
}
}
out:
xprt_wake_pending_tasks(xprt, status);
out_clear:
xprt_clear_connecting(xprt);
}
/**
* xs_connect - connect a socket to a remote endpoint
* @task: address of RPC task that manages state of connect request
*
* TCP: If the remote end dropped the connection, delay reconnecting.
*
* UDP socket connects are synchronous, but we use a work queue anyway
* to guarantee that even unprivileged user processes can set up a
* socket on a privileged port.
*
* If a UDP socket connect fails, the delay behavior here prevents
* retry floods (hard mounts).
*/
static void xs_connect(struct rpc_task *task)
{
struct rpc_xprt *xprt = task->tk_xprt;
if (xprt_test_and_set_connecting(xprt))
return;
if (xprt->sock != NULL) {
dprintk("RPC: xs_connect delayed xprt %p for %lu seconds\n",
xprt, xprt->reestablish_timeout / HZ);
schedule_delayed_work(&xprt->connect_worker,
xprt->reestablish_timeout);
xprt->reestablish_timeout <<= 1;
if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
} else {
dprintk("RPC: xs_connect scheduled xprt %p\n", xprt);
schedule_work(&xprt->connect_worker);
/* flush_scheduled_work can sleep... */
if (!RPC_IS_ASYNC(task))
flush_scheduled_work();
}
}
static struct rpc_xprt_ops xs_udp_ops = {
.set_buffer_size = xs_udp_set_buffer_size,
.reserve_xprt = xprt_reserve_xprt_cong,
.release_xprt = xprt_release_xprt_cong,
.connect = xs_connect,
.send_request = xs_udp_send_request,
.set_retrans_timeout = xprt_set_retrans_timeout_rtt,
.timer = xs_udp_timer,
.release_request = xprt_release_rqst_cong,
.close = xs_close,
.destroy = xs_destroy,
};
static struct rpc_xprt_ops xs_tcp_ops = {
.reserve_xprt = xprt_reserve_xprt,
.release_xprt = xprt_release_xprt,
.connect = xs_connect,
.send_request = xs_tcp_send_request,
.set_retrans_timeout = xprt_set_retrans_timeout_def,
.close = xs_close,
.destroy = xs_destroy,
};
/**
* xs_setup_udp - Set up transport to use a UDP socket
* @xprt: transport to set up
* @to: timeout parameters
*
*/
int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
{
size_t slot_table_size;
dprintk("RPC: setting up udp-ipv4 transport...\n");
xprt->max_reqs = xprt_udp_slot_table_entries;
slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
if (xprt->slot == NULL)
return -ENOMEM;
memset(xprt->slot, 0, slot_table_size);
xprt->prot = IPPROTO_UDP;
xprt->port = xprt_max_resvport;
xprt->tsh_size = 0;
xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
/* XXX: header size can vary due to auth type, IPv6, etc. */
xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt);
xprt->bind_timeout = XS_BIND_TO;
xprt->connect_timeout = XS_UDP_CONN_TO;
xprt->reestablish_timeout = XS_UDP_REEST_TO;
xprt->idle_timeout = XS_IDLE_DISC_TO;
xprt->ops = &xs_udp_ops;
if (to)
xprt->timeout = *to;
else
xprt_set_timeout(&xprt->timeout, 5, 5 * HZ);
return 0;
}
/**
* xs_setup_tcp - Set up transport to use a TCP socket
* @xprt: transport to set up
* @to: timeout parameters
*
*/
int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
{
size_t slot_table_size;
dprintk("RPC: setting up tcp-ipv4 transport...\n");
xprt->max_reqs = xprt_tcp_slot_table_entries;
slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
if (xprt->slot == NULL)
return -ENOMEM;
memset(xprt->slot, 0, slot_table_size);
xprt->prot = IPPROTO_TCP;
xprt->port = xprt_max_resvport;
xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);
xprt->bind_timeout = XS_BIND_TO;
xprt->connect_timeout = XS_TCP_CONN_TO;
xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
xprt->idle_timeout = XS_IDLE_DISC_TO;
xprt->ops = &xs_tcp_ops;
if (to)
xprt->timeout = *to;
else
xprt_set_timeout(&xprt->timeout, 2, 60 * HZ);
return 0;
}
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