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linux-sg2042/net/sunrpc/svcsock.c

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/*
* linux/net/sunrpc/svcsock.c
*
* These are the RPC server socket internals.
*
* The server scheduling algorithm does not always distribute the load
* evenly when servicing a single client. May need to modify the
* svc_sock_enqueue procedure...
*
* TCP support is largely untested and may be a little slow. The problem
* is that we currently do two separate recvfrom's, one for the 4-byte
* record length, and the second for the actual record. This could possibly
* be improved by always reading a minimum size of around 100 bytes and
* tucking any superfluous bytes away in a temporary store. Still, that
* leaves write requests out in the rain. An alternative may be to peek at
* the first skb in the queue, and if it matches the next TCP sequence
* number, to extract the record marker. Yuck.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/udp.h>
#include <linux/tcp.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <net/ip.h>
#include <net/tcp_states.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/stats.h>
/* SMP locking strategy:
*
* svc_serv->sv_lock protects most stuff for that service.
*
* Some flags can be set to certain values at any time
* providing that certain rules are followed:
*
* SK_BUSY can be set to 0 at any time.
* svc_sock_enqueue must be called afterwards
* SK_CONN, SK_DATA, can be set or cleared at any time.
* after a set, svc_sock_enqueue must be called.
* after a clear, the socket must be read/accepted
* if this succeeds, it must be set again.
* SK_CLOSE can set at any time. It is never cleared.
*
*/
#define RPCDBG_FACILITY RPCDBG_SVCSOCK
static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
int *errp, int pmap_reg);
static void svc_udp_data_ready(struct sock *, int);
static int svc_udp_recvfrom(struct svc_rqst *);
static int svc_udp_sendto(struct svc_rqst *);
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);
static int svc_deferred_recv(struct svc_rqst *rqstp);
static struct cache_deferred_req *svc_defer(struct cache_req *req);
/*
* Queue up an idle server thread. Must have serv->sv_lock held.
* Note: this is really a stack rather than a queue, so that we only
* use as many different threads as we need, and the rest don't polute
* the cache.
*/
static inline void
svc_serv_enqueue(struct svc_serv *serv, struct svc_rqst *rqstp)
{
list_add(&rqstp->rq_list, &serv->sv_threads);
}
/*
* Dequeue an nfsd thread. Must have serv->sv_lock held.
*/
static inline void
svc_serv_dequeue(struct svc_serv *serv, struct svc_rqst *rqstp)
{
list_del(&rqstp->rq_list);
}
/*
* Release an skbuff after use
*/
static inline void
svc_release_skb(struct svc_rqst *rqstp)
{
struct sk_buff *skb = rqstp->rq_skbuff;
struct svc_deferred_req *dr = rqstp->rq_deferred;
if (skb) {
rqstp->rq_skbuff = NULL;
dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
skb_free_datagram(rqstp->rq_sock->sk_sk, skb);
}
if (dr) {
rqstp->rq_deferred = NULL;
kfree(dr);
}
}
/*
* Any space to write?
*/
static inline unsigned long
svc_sock_wspace(struct svc_sock *svsk)
{
int wspace;
if (svsk->sk_sock->type == SOCK_STREAM)
wspace = sk_stream_wspace(svsk->sk_sk);
else
wspace = sock_wspace(svsk->sk_sk);
return wspace;
}
/*
* Queue up a socket with data pending. If there are idle nfsd
* processes, wake 'em up.
*
*/
static void
svc_sock_enqueue(struct svc_sock *svsk)
{
struct svc_serv *serv = svsk->sk_server;
struct svc_rqst *rqstp;
if (!(svsk->sk_flags &
( (1<<SK_CONN)|(1<<SK_DATA)|(1<<SK_CLOSE)|(1<<SK_DEFERRED)) ))
return;
if (test_bit(SK_DEAD, &svsk->sk_flags))
return;
spin_lock_bh(&serv->sv_lock);
if (!list_empty(&serv->sv_threads) &&
!list_empty(&serv->sv_sockets))
printk(KERN_ERR
"svc_sock_enqueue: threads and sockets both waiting??\n");
if (test_bit(SK_DEAD, &svsk->sk_flags)) {
/* Don't enqueue dead sockets */
dprintk("svc: socket %p is dead, not enqueued\n", svsk->sk_sk);
goto out_unlock;
}
if (test_bit(SK_BUSY, &svsk->sk_flags)) {
/* Don't enqueue socket while daemon is receiving */
dprintk("svc: socket %p busy, not enqueued\n", svsk->sk_sk);
goto out_unlock;
}
set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
if (((svsk->sk_reserved + serv->sv_bufsz)*2
> svc_sock_wspace(svsk))
&& !test_bit(SK_CLOSE, &svsk->sk_flags)
&& !test_bit(SK_CONN, &svsk->sk_flags)) {
/* Don't enqueue while not enough space for reply */
dprintk("svc: socket %p no space, %d*2 > %ld, not enqueued\n",
svsk->sk_sk, svsk->sk_reserved+serv->sv_bufsz,
svc_sock_wspace(svsk));
goto out_unlock;
}
clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
/* Mark socket as busy. It will remain in this state until the
* server has processed all pending data and put the socket back
* on the idle list.
*/
set_bit(SK_BUSY, &svsk->sk_flags);
if (!list_empty(&serv->sv_threads)) {
rqstp = list_entry(serv->sv_threads.next,
struct svc_rqst,
rq_list);
dprintk("svc: socket %p served by daemon %p\n",
svsk->sk_sk, rqstp);
svc_serv_dequeue(serv, rqstp);
if (rqstp->rq_sock)
printk(KERN_ERR
"svc_sock_enqueue: server %p, rq_sock=%p!\n",
rqstp, rqstp->rq_sock);
rqstp->rq_sock = svsk;
svsk->sk_inuse++;
rqstp->rq_reserved = serv->sv_bufsz;
svsk->sk_reserved += rqstp->rq_reserved;
wake_up(&rqstp->rq_wait);
} else {
dprintk("svc: socket %p put into queue\n", svsk->sk_sk);
list_add_tail(&svsk->sk_ready, &serv->sv_sockets);
}
out_unlock:
spin_unlock_bh(&serv->sv_lock);
}
/*
* Dequeue the first socket. Must be called with the serv->sv_lock held.
*/
static inline struct svc_sock *
svc_sock_dequeue(struct svc_serv *serv)
{
struct svc_sock *svsk;
if (list_empty(&serv->sv_sockets))
return NULL;
svsk = list_entry(serv->sv_sockets.next,
struct svc_sock, sk_ready);
list_del_init(&svsk->sk_ready);
dprintk("svc: socket %p dequeued, inuse=%d\n",
svsk->sk_sk, svsk->sk_inuse);
return svsk;
}
/*
* Having read something from a socket, check whether it
* needs to be re-enqueued.
* Note: SK_DATA only gets cleared when a read-attempt finds
* no (or insufficient) data.
*/
static inline void
svc_sock_received(struct svc_sock *svsk)
{
clear_bit(SK_BUSY, &svsk->sk_flags);
svc_sock_enqueue(svsk);
}
/**
* svc_reserve - change the space reserved for the reply to a request.
* @rqstp: The request in question
* @space: new max space to reserve
*
* Each request reserves some space on the output queue of the socket
* to make sure the reply fits. This function reduces that reserved
* space to be the amount of space used already, plus @space.
*
*/
void svc_reserve(struct svc_rqst *rqstp, int space)
{
space += rqstp->rq_res.head[0].iov_len;
if (space < rqstp->rq_reserved) {
struct svc_sock *svsk = rqstp->rq_sock;
spin_lock_bh(&svsk->sk_server->sv_lock);
svsk->sk_reserved -= (rqstp->rq_reserved - space);
rqstp->rq_reserved = space;
spin_unlock_bh(&svsk->sk_server->sv_lock);
svc_sock_enqueue(svsk);
}
}
/*
* Release a socket after use.
*/
static inline void
svc_sock_put(struct svc_sock *svsk)
{
struct svc_serv *serv = svsk->sk_server;
spin_lock_bh(&serv->sv_lock);
if (!--(svsk->sk_inuse) && test_bit(SK_DEAD, &svsk->sk_flags)) {
spin_unlock_bh(&serv->sv_lock);
dprintk("svc: releasing dead socket\n");
sock_release(svsk->sk_sock);
kfree(svsk);
}
else
spin_unlock_bh(&serv->sv_lock);
}
static void
svc_sock_release(struct svc_rqst *rqstp)
{
struct svc_sock *svsk = rqstp->rq_sock;
svc_release_skb(rqstp);
svc_free_allpages(rqstp);
rqstp->rq_res.page_len = 0;
rqstp->rq_res.page_base = 0;
/* Reset response buffer and release
* the reservation.
* But first, check that enough space was reserved
* for the reply, otherwise we have a bug!
*/
if ((rqstp->rq_res.len) > rqstp->rq_reserved)
printk(KERN_ERR "RPC request reserved %d but used %d\n",
rqstp->rq_reserved,
rqstp->rq_res.len);
rqstp->rq_res.head[0].iov_len = 0;
svc_reserve(rqstp, 0);
rqstp->rq_sock = NULL;
svc_sock_put(svsk);
}
/*
* External function to wake up a server waiting for data
*/
void
svc_wake_up(struct svc_serv *serv)
{
struct svc_rqst *rqstp;
spin_lock_bh(&serv->sv_lock);
if (!list_empty(&serv->sv_threads)) {
rqstp = list_entry(serv->sv_threads.next,
struct svc_rqst,
rq_list);
dprintk("svc: daemon %p woken up.\n", rqstp);
/*
svc_serv_dequeue(serv, rqstp);
rqstp->rq_sock = NULL;
*/
wake_up(&rqstp->rq_wait);
}
spin_unlock_bh(&serv->sv_lock);
}
/*
* Generic sendto routine
*/
static int
svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
{
struct svc_sock *svsk = rqstp->rq_sock;
struct socket *sock = svsk->sk_sock;
int slen;
char buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
struct cmsghdr *cmh = (struct cmsghdr *)buffer;
struct in_pktinfo *pki = (struct in_pktinfo *)CMSG_DATA(cmh);
int len = 0;
int result;
int size;
struct page **ppage = xdr->pages;
size_t base = xdr->page_base;
unsigned int pglen = xdr->page_len;
unsigned int flags = MSG_MORE;
slen = xdr->len;
if (rqstp->rq_prot == IPPROTO_UDP) {
/* set the source and destination */
struct msghdr msg;
msg.msg_name = &rqstp->rq_addr;
msg.msg_namelen = sizeof(rqstp->rq_addr);
msg.msg_iov = NULL;
msg.msg_iovlen = 0;
msg.msg_flags = MSG_MORE;
msg.msg_control = cmh;
msg.msg_controllen = sizeof(buffer);
cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
cmh->cmsg_level = SOL_IP;
cmh->cmsg_type = IP_PKTINFO;
pki->ipi_ifindex = 0;
pki->ipi_spec_dst.s_addr = rqstp->rq_daddr;
if (sock_sendmsg(sock, &msg, 0) < 0)
goto out;
}
/* send head */
if (slen == xdr->head[0].iov_len)
flags = 0;
len = sock->ops->sendpage(sock, rqstp->rq_respages[0], 0, xdr->head[0].iov_len, flags);
if (len != xdr->head[0].iov_len)
goto out;
slen -= xdr->head[0].iov_len;
if (slen == 0)
goto out;
/* send page data */
size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
while (pglen > 0) {
if (slen == size)
flags = 0;
result = sock->ops->sendpage(sock, *ppage, base, size, flags);
if (result > 0)
len += result;
if (result != size)
goto out;
slen -= size;
pglen -= size;
size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
base = 0;
ppage++;
}
/* send tail */
if (xdr->tail[0].iov_len) {
result = sock->ops->sendpage(sock, rqstp->rq_respages[rqstp->rq_restailpage],
((unsigned long)xdr->tail[0].iov_base)& (PAGE_SIZE-1),
xdr->tail[0].iov_len, 0);
if (result > 0)
len += result;
}
out:
dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %x)\n",
rqstp->rq_sock, xdr->head[0].iov_base, xdr->head[0].iov_len, xdr->len, len,
rqstp->rq_addr.sin_addr.s_addr);
return len;
}
/*
* Check input queue length
*/
static int
svc_recv_available(struct svc_sock *svsk)
{
mm_segment_t oldfs;
struct socket *sock = svsk->sk_sock;
int avail, err;
oldfs = get_fs(); set_fs(KERNEL_DS);
err = sock->ops->ioctl(sock, TIOCINQ, (unsigned long) &avail);
set_fs(oldfs);
return (err >= 0)? avail : err;
}
/*
* Generic recvfrom routine.
*/
static int
svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr, int buflen)
{
struct msghdr msg;
struct socket *sock;
int len, alen;
rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
sock = rqstp->rq_sock->sk_sock;
msg.msg_name = &rqstp->rq_addr;
msg.msg_namelen = sizeof(rqstp->rq_addr);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = MSG_DONTWAIT;
len = kernel_recvmsg(sock, &msg, iov, nr, buflen, MSG_DONTWAIT);
/* sock_recvmsg doesn't fill in the name/namelen, so we must..
* possibly we should cache this in the svc_sock structure
* at accept time. FIXME
*/
alen = sizeof(rqstp->rq_addr);
sock->ops->getname(sock, (struct sockaddr *)&rqstp->rq_addr, &alen, 1);
dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
rqstp->rq_sock, iov[0].iov_base, iov[0].iov_len, len);
return len;
}
/*
* Set socket snd and rcv buffer lengths
*/
static inline void
svc_sock_setbufsize(struct socket *sock, unsigned int snd, unsigned int rcv)
{
#if 0
mm_segment_t oldfs;
oldfs = get_fs(); set_fs(KERNEL_DS);
sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
(char*)&snd, sizeof(snd));
sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
(char*)&rcv, sizeof(rcv));
#else
/* sock_setsockopt limits use to sysctl_?mem_max,
* which isn't acceptable. Until that is made conditional
* on not having CAP_SYS_RESOURCE or similar, we go direct...
* DaveM said I could!
*/
lock_sock(sock->sk);
sock->sk->sk_sndbuf = snd * 2;
sock->sk->sk_rcvbuf = rcv * 2;
sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
release_sock(sock->sk);
#endif
}
/*
* INET callback when data has been received on the socket.
*/
static void
svc_udp_data_ready(struct sock *sk, int count)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
if (svsk) {
dprintk("svc: socket %p(inet %p), count=%d, busy=%d\n",
svsk, sk, count, test_bit(SK_BUSY, &svsk->sk_flags));
set_bit(SK_DATA, &svsk->sk_flags);
svc_sock_enqueue(svsk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible(sk->sk_sleep);
}
/*
* INET callback when space is newly available on the socket.
*/
static void
svc_write_space(struct sock *sk)
{
struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
if (svsk) {
dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
svsk, sk, test_bit(SK_BUSY, &svsk->sk_flags));
svc_sock_enqueue(svsk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) {
dprintk("RPC svc_write_space: someone sleeping on %p\n",
svsk);
wake_up_interruptible(sk->sk_sleep);
}
}
/*
* Receive a datagram from a UDP socket.
*/
static int
svc_udp_recvfrom(struct svc_rqst *rqstp)
{
struct svc_sock *svsk = rqstp->rq_sock;
struct svc_serv *serv = svsk->sk_server;
struct sk_buff *skb;
int err, len;
if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
/* udp sockets need large rcvbuf as all pending
* requests are still in that buffer. sndbuf must
* also be large enough that there is enough space
* for one reply per thread.
*/
svc_sock_setbufsize(svsk->sk_sock,
(serv->sv_nrthreads+3) * serv->sv_bufsz,
(serv->sv_nrthreads+3) * serv->sv_bufsz);
if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
svc_sock_received(svsk);
return svc_deferred_recv(rqstp);
}
clear_bit(SK_DATA, &svsk->sk_flags);
while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
if (err == -EAGAIN) {
svc_sock_received(svsk);
return err;
}
/* possibly an icmp error */
dprintk("svc: recvfrom returned error %d\n", -err);
}
if (skb->tstamp.off_sec == 0) {
struct timeval tv;
tv.tv_sec = xtime.tv_sec;
tv.tv_usec = xtime.tv_nsec / NSEC_PER_USEC;
skb_set_timestamp(skb, &tv);
/* Don't enable netstamp, sunrpc doesn't
need that much accuracy */
}
skb_get_timestamp(skb, &svsk->sk_sk->sk_stamp);
set_bit(SK_DATA, &svsk->sk_flags); /* there may be more data... */
/*
* Maybe more packets - kick another thread ASAP.
*/
svc_sock_received(svsk);
len = skb->len - sizeof(struct udphdr);
rqstp->rq_arg.len = len;
rqstp->rq_prot = IPPROTO_UDP;
/* Get sender address */
rqstp->rq_addr.sin_family = AF_INET;
rqstp->rq_addr.sin_port = skb->h.uh->source;
rqstp->rq_addr.sin_addr.s_addr = skb->nh.iph->saddr;
rqstp->rq_daddr = skb->nh.iph->daddr;
if (skb_is_nonlinear(skb)) {
/* we have to copy */
local_bh_disable();
if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
local_bh_enable();
/* checksum error */
skb_free_datagram(svsk->sk_sk, skb);
return 0;
}
local_bh_enable();
skb_free_datagram(svsk->sk_sk, skb);
} else {
/* we can use it in-place */
rqstp->rq_arg.head[0].iov_base = skb->data + sizeof(struct udphdr);
rqstp->rq_arg.head[0].iov_len = len;
if (skb_checksum_complete(skb)) {
skb_free_datagram(svsk->sk_sk, skb);
return 0;
}
rqstp->rq_skbuff = skb;
}
rqstp->rq_arg.page_base = 0;
if (len <= rqstp->rq_arg.head[0].iov_len) {
rqstp->rq_arg.head[0].iov_len = len;
rqstp->rq_arg.page_len = 0;
} else {
rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
rqstp->rq_argused += (rqstp->rq_arg.page_len + PAGE_SIZE - 1)/ PAGE_SIZE;
}
if (serv->sv_stats)
serv->sv_stats->netudpcnt++;
return len;
}
static int
svc_udp_sendto(struct svc_rqst *rqstp)
{
int error;
error = svc_sendto(rqstp, &rqstp->rq_res);
if (error == -ECONNREFUSED)
/* ICMP error on earlier request. */
error = svc_sendto(rqstp, &rqstp->rq_res);
return error;
}
static void
svc_udp_init(struct svc_sock *svsk)
{
svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
svsk->sk_sk->sk_write_space = svc_write_space;
svsk->sk_recvfrom = svc_udp_recvfrom;
svsk->sk_sendto = svc_udp_sendto;
/* initialise setting must have enough space to
* receive and respond to one request.
* svc_udp_recvfrom will re-adjust if necessary
*/
svc_sock_setbufsize(svsk->sk_sock,
3 * svsk->sk_server->sv_bufsz,
3 * svsk->sk_server->sv_bufsz);
set_bit(SK_DATA, &svsk->sk_flags); /* might have come in before data_ready set up */
set_bit(SK_CHNGBUF, &svsk->sk_flags);
}
/*
* A data_ready event on a listening socket means there's a connection
* pending. Do not use state_change as a substitute for it.
*/
static void
svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
dprintk("svc: socket %p TCP (listen) state change %d\n",
sk, sk->sk_state);
/*
* This callback may called twice when a new connection
* is established as a child socket inherits everything
* from a parent LISTEN socket.
* 1) data_ready method of the parent socket will be called
* when one of child sockets become ESTABLISHED.
* 2) data_ready method of the child socket may be called
* when it receives data before the socket is accepted.
* In case of 2, we should ignore it silently.
*/
if (sk->sk_state == TCP_LISTEN) {
if (svsk) {
set_bit(SK_CONN, &svsk->sk_flags);
svc_sock_enqueue(svsk);
} else
printk("svc: socket %p: no user data\n", sk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible_all(sk->sk_sleep);
}
/*
* A state change on a connected socket means it's dying or dead.
*/
static void
svc_tcp_state_change(struct sock *sk)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
sk, sk->sk_state, sk->sk_user_data);
if (!svsk)
printk("svc: socket %p: no user data\n", sk);
else {
set_bit(SK_CLOSE, &svsk->sk_flags);
svc_sock_enqueue(svsk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible_all(sk->sk_sleep);
}
static void
svc_tcp_data_ready(struct sock *sk, int count)
{
struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
dprintk("svc: socket %p TCP data ready (svsk %p)\n",
sk, sk->sk_user_data);
if (svsk) {
set_bit(SK_DATA, &svsk->sk_flags);
svc_sock_enqueue(svsk);
}
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
wake_up_interruptible(sk->sk_sleep);
}
/*
* Accept a TCP connection
*/
static void
svc_tcp_accept(struct svc_sock *svsk)
{
struct sockaddr_in sin;
struct svc_serv *serv = svsk->sk_server;
struct socket *sock = svsk->sk_sock;
struct socket *newsock;
const struct proto_ops *ops;
struct svc_sock *newsvsk;
int err, slen;
dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
if (!sock)
return;
err = sock_create_lite(PF_INET, SOCK_STREAM, IPPROTO_TCP, &newsock);
if (err) {
if (err == -ENOMEM)
printk(KERN_WARNING "%s: no more sockets!\n",
serv->sv_name);
return;
}
dprintk("svc: tcp_accept %p allocated\n", newsock);
newsock->ops = ops = sock->ops;
clear_bit(SK_CONN, &svsk->sk_flags);
if ((err = ops->accept(sock, newsock, O_NONBLOCK)) < 0) {
if (err != -EAGAIN && net_ratelimit())
printk(KERN_WARNING "%s: accept failed (err %d)!\n",
serv->sv_name, -err);
goto failed; /* aborted connection or whatever */
}
set_bit(SK_CONN, &svsk->sk_flags);
svc_sock_enqueue(svsk);
slen = sizeof(sin);
err = ops->getname(newsock, (struct sockaddr *) &sin, &slen, 1);
if (err < 0) {
if (net_ratelimit())
printk(KERN_WARNING "%s: peername failed (err %d)!\n",
serv->sv_name, -err);
goto failed; /* aborted connection or whatever */
}
/* Ideally, we would want to reject connections from unauthorized
* hosts here, but when we get encription, the IP of the host won't
* tell us anything. For now just warn about unpriv connections.
*/
if (ntohs(sin.sin_port) >= 1024) {
dprintk(KERN_WARNING
"%s: connect from unprivileged port: %u.%u.%u.%u:%d\n",
serv->sv_name,
NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
}
dprintk("%s: connect from %u.%u.%u.%u:%04x\n", serv->sv_name,
NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
/* make sure that a write doesn't block forever when
* low on memory
*/
newsock->sk->sk_sndtimeo = HZ*30;
if (!(newsvsk = svc_setup_socket(serv, newsock, &err, 0)))
goto failed;
/* make sure that we don't have too many active connections.
* If we have, something must be dropped.
*
* There's no point in trying to do random drop here for
* DoS prevention. The NFS clients does 1 reconnect in 15
* seconds. An attacker can easily beat that.
*
* The only somewhat efficient mechanism would be if drop
* old connections from the same IP first. But right now
* we don't even record the client IP in svc_sock.
*/
if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) {
struct svc_sock *svsk = NULL;
spin_lock_bh(&serv->sv_lock);
if (!list_empty(&serv->sv_tempsocks)) {
if (net_ratelimit()) {
/* Try to help the admin */
printk(KERN_NOTICE "%s: too many open TCP "
"sockets, consider increasing the "
"number of nfsd threads\n",
serv->sv_name);
printk(KERN_NOTICE "%s: last TCP connect from "
"%u.%u.%u.%u:%d\n",
serv->sv_name,
NIPQUAD(sin.sin_addr.s_addr),
ntohs(sin.sin_port));
}
/*
* Always select the oldest socket. It's not fair,
* but so is life
*/
svsk = list_entry(serv->sv_tempsocks.prev,
struct svc_sock,
sk_list);
set_bit(SK_CLOSE, &svsk->sk_flags);
svsk->sk_inuse ++;
}
spin_unlock_bh(&serv->sv_lock);
if (svsk) {
svc_sock_enqueue(svsk);
svc_sock_put(svsk);
}
}
if (serv->sv_stats)
serv->sv_stats->nettcpconn++;
return;
failed:
sock_release(newsock);
return;
}
/*
* Receive data from a TCP socket.
*/
static int
svc_tcp_recvfrom(struct svc_rqst *rqstp)
{
struct svc_sock *svsk = rqstp->rq_sock;
struct svc_serv *serv = svsk->sk_server;
int len;
struct kvec vec[RPCSVC_MAXPAGES];
int pnum, vlen;
dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
svsk, test_bit(SK_DATA, &svsk->sk_flags),
test_bit(SK_CONN, &svsk->sk_flags),
test_bit(SK_CLOSE, &svsk->sk_flags));
if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
svc_sock_received(svsk);
return svc_deferred_recv(rqstp);
}
if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
svc_delete_socket(svsk);
return 0;
}
if (test_bit(SK_CONN, &svsk->sk_flags)) {
svc_tcp_accept(svsk);
svc_sock_received(svsk);
return 0;
}
if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
/* sndbuf needs to have room for one request
* per thread, otherwise we can stall even when the
* network isn't a bottleneck.
* rcvbuf just needs to be able to hold a few requests.
* Normally they will be removed from the queue
* as soon a a complete request arrives.
*/
svc_sock_setbufsize(svsk->sk_sock,
(serv->sv_nrthreads+3) * serv->sv_bufsz,
3 * serv->sv_bufsz);
clear_bit(SK_DATA, &svsk->sk_flags);
/* Receive data. If we haven't got the record length yet, get
* the next four bytes. Otherwise try to gobble up as much as
* possible up to the complete record length.
*/
if (svsk->sk_tcplen < 4) {
unsigned long want = 4 - svsk->sk_tcplen;
struct kvec iov;
iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
iov.iov_len = want;
if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
goto error;
svsk->sk_tcplen += len;
if (len < want) {
dprintk("svc: short recvfrom while reading record length (%d of %lu)\n",
len, want);
svc_sock_received(svsk);
return -EAGAIN; /* record header not complete */
}
svsk->sk_reclen = ntohl(svsk->sk_reclen);
if (!(svsk->sk_reclen & 0x80000000)) {
/* FIXME: technically, a record can be fragmented,
* and non-terminal fragments will not have the top
* bit set in the fragment length header.
* But apparently no known nfs clients send fragmented
* records. */
printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx (non-terminal)\n",
(unsigned long) svsk->sk_reclen);
goto err_delete;
}
svsk->sk_reclen &= 0x7fffffff;
dprintk("svc: TCP record, %d bytes\n", svsk->sk_reclen);
if (svsk->sk_reclen > serv->sv_bufsz) {
printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx (large)\n",
(unsigned long) svsk->sk_reclen);
goto err_delete;
}
}
/* Check whether enough data is available */
len = svc_recv_available(svsk);
if (len < 0)
goto error;
if (len < svsk->sk_reclen) {
dprintk("svc: incomplete TCP record (%d of %d)\n",
len, svsk->sk_reclen);
svc_sock_received(svsk);
return -EAGAIN; /* record not complete */
}
len = svsk->sk_reclen;
set_bit(SK_DATA, &svsk->sk_flags);
vec[0] = rqstp->rq_arg.head[0];
vlen = PAGE_SIZE;
pnum = 1;
while (vlen < len) {
vec[pnum].iov_base = page_address(rqstp->rq_argpages[rqstp->rq_argused++]);
vec[pnum].iov_len = PAGE_SIZE;
pnum++;
vlen += PAGE_SIZE;
}
/* Now receive data */
len = svc_recvfrom(rqstp, vec, pnum, len);
if (len < 0)
goto error;
dprintk("svc: TCP complete record (%d bytes)\n", len);
rqstp->rq_arg.len = len;
rqstp->rq_arg.page_base = 0;
if (len <= rqstp->rq_arg.head[0].iov_len) {
rqstp->rq_arg.head[0].iov_len = len;
rqstp->rq_arg.page_len = 0;
} else {
rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
}
rqstp->rq_skbuff = NULL;
rqstp->rq_prot = IPPROTO_TCP;
/* Reset TCP read info */
svsk->sk_reclen = 0;
svsk->sk_tcplen = 0;
svc_sock_received(svsk);
if (serv->sv_stats)
serv->sv_stats->nettcpcnt++;
return len;
err_delete:
svc_delete_socket(svsk);
return -EAGAIN;
error:
if (len == -EAGAIN) {
dprintk("RPC: TCP recvfrom got EAGAIN\n");
svc_sock_received(svsk);
} else {
printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
svsk->sk_server->sv_name, -len);
goto err_delete;
}
return len;
}
/*
* Send out data on TCP socket.
*/
static int
svc_tcp_sendto(struct svc_rqst *rqstp)
{
struct xdr_buf *xbufp = &rqstp->rq_res;
int sent;
u32 reclen;
/* Set up the first element of the reply kvec.
* Any other kvecs that may be in use have been taken
* care of by the server implementation itself.
*/
reclen = htonl(0x80000000|((xbufp->len ) - 4));
memcpy(xbufp->head[0].iov_base, &reclen, 4);
if (test_bit(SK_DEAD, &rqstp->rq_sock->sk_flags))
return -ENOTCONN;
sent = svc_sendto(rqstp, &rqstp->rq_res);
if (sent != xbufp->len) {
printk(KERN_NOTICE "rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n",
rqstp->rq_sock->sk_server->sv_name,
(sent<0)?"got error":"sent only",
sent, xbufp->len);
svc_delete_socket(rqstp->rq_sock);
sent = -EAGAIN;
}
return sent;
}
static void
svc_tcp_init(struct svc_sock *svsk)
{
struct sock *sk = svsk->sk_sk;
struct tcp_sock *tp = tcp_sk(sk);
svsk->sk_recvfrom = svc_tcp_recvfrom;
svsk->sk_sendto = svc_tcp_sendto;
if (sk->sk_state == TCP_LISTEN) {
dprintk("setting up TCP socket for listening\n");
sk->sk_data_ready = svc_tcp_listen_data_ready;
set_bit(SK_CONN, &svsk->sk_flags);
} else {
dprintk("setting up TCP socket for reading\n");
sk->sk_state_change = svc_tcp_state_change;
sk->sk_data_ready = svc_tcp_data_ready;
sk->sk_write_space = svc_write_space;
svsk->sk_reclen = 0;
svsk->sk_tcplen = 0;
tp->nonagle = 1; /* disable Nagle's algorithm */
/* initialise setting must have enough space to
* receive and respond to one request.
* svc_tcp_recvfrom will re-adjust if necessary
*/
svc_sock_setbufsize(svsk->sk_sock,
3 * svsk->sk_server->sv_bufsz,
3 * svsk->sk_server->sv_bufsz);
set_bit(SK_CHNGBUF, &svsk->sk_flags);
set_bit(SK_DATA, &svsk->sk_flags);
if (sk->sk_state != TCP_ESTABLISHED)
set_bit(SK_CLOSE, &svsk->sk_flags);
}
}
void
svc_sock_update_bufs(struct svc_serv *serv)
{
/*
* The number of server threads has changed. Update
* rcvbuf and sndbuf accordingly on all sockets
*/
struct list_head *le;
spin_lock_bh(&serv->sv_lock);
list_for_each(le, &serv->sv_permsocks) {
struct svc_sock *svsk =
list_entry(le, struct svc_sock, sk_list);
set_bit(SK_CHNGBUF, &svsk->sk_flags);
}
list_for_each(le, &serv->sv_tempsocks) {
struct svc_sock *svsk =
list_entry(le, struct svc_sock, sk_list);
set_bit(SK_CHNGBUF, &svsk->sk_flags);
}
spin_unlock_bh(&serv->sv_lock);
}
/*
* Receive the next request on any socket.
*/
int
svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
{
struct svc_sock *svsk =NULL;
int len;
int pages;
struct xdr_buf *arg;
DECLARE_WAITQUEUE(wait, current);
dprintk("svc: server %p waiting for data (to = %ld)\n",
rqstp, timeout);
if (rqstp->rq_sock)
printk(KERN_ERR
"svc_recv: service %p, socket not NULL!\n",
rqstp);
if (waitqueue_active(&rqstp->rq_wait))
printk(KERN_ERR
"svc_recv: service %p, wait queue active!\n",
rqstp);
/* Initialize the buffers */
/* first reclaim pages that were moved to response list */
svc_pushback_allpages(rqstp);
/* now allocate needed pages. If we get a failure, sleep briefly */
pages = 2 + (serv->sv_bufsz + PAGE_SIZE -1) / PAGE_SIZE;
while (rqstp->rq_arghi < pages) {
struct page *p = alloc_page(GFP_KERNEL);
if (!p) {
schedule_timeout_uninterruptible(msecs_to_jiffies(500));
continue;
}
rqstp->rq_argpages[rqstp->rq_arghi++] = p;
}
/* Make arg->head point to first page and arg->pages point to rest */
arg = &rqstp->rq_arg;
arg->head[0].iov_base = page_address(rqstp->rq_argpages[0]);
arg->head[0].iov_len = PAGE_SIZE;
rqstp->rq_argused = 1;
arg->pages = rqstp->rq_argpages + 1;
arg->page_base = 0;
/* save at least one page for response */
arg->page_len = (pages-2)*PAGE_SIZE;
arg->len = (pages-1)*PAGE_SIZE;
arg->tail[0].iov_len = 0;
try_to_freeze();
cond_resched();
if (signalled())
return -EINTR;
spin_lock_bh(&serv->sv_lock);
if (!list_empty(&serv->sv_tempsocks)) {
svsk = list_entry(serv->sv_tempsocks.next,
struct svc_sock, sk_list);
/* apparently the "standard" is that clients close
* idle connections after 5 minutes, servers after
* 6 minutes
* http://www.connectathon.org/talks96/nfstcp.pdf
*/
if (get_seconds() - svsk->sk_lastrecv < 6*60
|| test_bit(SK_BUSY, &svsk->sk_flags))
svsk = NULL;
}
if (svsk) {
set_bit(SK_BUSY, &svsk->sk_flags);
set_bit(SK_CLOSE, &svsk->sk_flags);
rqstp->rq_sock = svsk;
svsk->sk_inuse++;
} else if ((svsk = svc_sock_dequeue(serv)) != NULL) {
rqstp->rq_sock = svsk;
svsk->sk_inuse++;
rqstp->rq_reserved = serv->sv_bufsz;
svsk->sk_reserved += rqstp->rq_reserved;
} else {
/* No data pending. Go to sleep */
svc_serv_enqueue(serv, rqstp);
/*
* We have to be able to interrupt this wait
* to bring down the daemons ...
*/
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&rqstp->rq_wait, &wait);
spin_unlock_bh(&serv->sv_lock);
schedule_timeout(timeout);
try_to_freeze();
spin_lock_bh(&serv->sv_lock);
remove_wait_queue(&rqstp->rq_wait, &wait);
if (!(svsk = rqstp->rq_sock)) {
svc_serv_dequeue(serv, rqstp);
spin_unlock_bh(&serv->sv_lock);
dprintk("svc: server %p, no data yet\n", rqstp);
return signalled()? -EINTR : -EAGAIN;
}
}
spin_unlock_bh(&serv->sv_lock);
dprintk("svc: server %p, socket %p, inuse=%d\n",
rqstp, svsk, svsk->sk_inuse);
len = svsk->sk_recvfrom(rqstp);
dprintk("svc: got len=%d\n", len);
/* No data, incomplete (TCP) read, or accept() */
if (len == 0 || len == -EAGAIN) {
rqstp->rq_res.len = 0;
svc_sock_release(rqstp);
return -EAGAIN;
}
svsk->sk_lastrecv = get_seconds();
if (test_bit(SK_TEMP, &svsk->sk_flags)) {
/* push active sockets to end of list */
spin_lock_bh(&serv->sv_lock);
if (!list_empty(&svsk->sk_list))
list_move_tail(&svsk->sk_list, &serv->sv_tempsocks);
spin_unlock_bh(&serv->sv_lock);
}
rqstp->rq_secure = ntohs(rqstp->rq_addr.sin_port) < 1024;
rqstp->rq_chandle.defer = svc_defer;
if (serv->sv_stats)
serv->sv_stats->netcnt++;
return len;
}
/*
* Drop request
*/
void
svc_drop(struct svc_rqst *rqstp)
{
dprintk("svc: socket %p dropped request\n", rqstp->rq_sock);
svc_sock_release(rqstp);
}
/*
* Return reply to client.
*/
int
svc_send(struct svc_rqst *rqstp)
{
struct svc_sock *svsk;
int len;
struct xdr_buf *xb;
if ((svsk = rqstp->rq_sock) == NULL) {
printk(KERN_WARNING "NULL socket pointer in %s:%d\n",
__FILE__, __LINE__);
return -EFAULT;
}
/* release the receive skb before sending the reply */
svc_release_skb(rqstp);
/* calculate over-all length */
xb = & rqstp->rq_res;
xb->len = xb->head[0].iov_len +
xb->page_len +
xb->tail[0].iov_len;
/* Grab svsk->sk_mutex to serialize outgoing data. */
mutex_lock(&svsk->sk_mutex);
if (test_bit(SK_DEAD, &svsk->sk_flags))
len = -ENOTCONN;
else
len = svsk->sk_sendto(rqstp);
mutex_unlock(&svsk->sk_mutex);
svc_sock_release(rqstp);
if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
return 0;
return len;
}
/*
* Initialize socket for RPC use and create svc_sock struct
* XXX: May want to setsockopt SO_SNDBUF and SO_RCVBUF.
*/
static struct svc_sock *
svc_setup_socket(struct svc_serv *serv, struct socket *sock,
int *errp, int pmap_register)
{
struct svc_sock *svsk;
struct sock *inet;
dprintk("svc: svc_setup_socket %p\n", sock);
if (!(svsk = kmalloc(sizeof(*svsk), GFP_KERNEL))) {
*errp = -ENOMEM;
return NULL;
}
memset(svsk, 0, sizeof(*svsk));
inet = sock->sk;
/* Register socket with portmapper */
if (*errp >= 0 && pmap_register)
*errp = svc_register(serv, inet->sk_protocol,
ntohs(inet_sk(inet)->sport));
if (*errp < 0) {
kfree(svsk);
return NULL;
}
set_bit(SK_BUSY, &svsk->sk_flags);
inet->sk_user_data = svsk;
svsk->sk_sock = sock;
svsk->sk_sk = inet;
svsk->sk_ostate = inet->sk_state_change;
svsk->sk_odata = inet->sk_data_ready;
svsk->sk_owspace = inet->sk_write_space;
svsk->sk_server = serv;
svsk->sk_lastrecv = get_seconds();
INIT_LIST_HEAD(&svsk->sk_deferred);
INIT_LIST_HEAD(&svsk->sk_ready);
mutex_init(&svsk->sk_mutex);
/* Initialize the socket */
if (sock->type == SOCK_DGRAM)
svc_udp_init(svsk);
else
svc_tcp_init(svsk);
spin_lock_bh(&serv->sv_lock);
if (!pmap_register) {
set_bit(SK_TEMP, &svsk->sk_flags);
list_add(&svsk->sk_list, &serv->sv_tempsocks);
serv->sv_tmpcnt++;
} else {
clear_bit(SK_TEMP, &svsk->sk_flags);
list_add(&svsk->sk_list, &serv->sv_permsocks);
}
spin_unlock_bh(&serv->sv_lock);
dprintk("svc: svc_setup_socket created %p (inet %p)\n",
svsk, svsk->sk_sk);
clear_bit(SK_BUSY, &svsk->sk_flags);
svc_sock_enqueue(svsk);
return svsk;
}
/*
* Create socket for RPC service.
*/
static int
svc_create_socket(struct svc_serv *serv, int protocol, struct sockaddr_in *sin)
{
struct svc_sock *svsk;
struct socket *sock;
int error;
int type;
dprintk("svc: svc_create_socket(%s, %d, %u.%u.%u.%u:%d)\n",
serv->sv_program->pg_name, protocol,
NIPQUAD(sin->sin_addr.s_addr),
ntohs(sin->sin_port));
if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
printk(KERN_WARNING "svc: only UDP and TCP "
"sockets supported\n");
return -EINVAL;
}
type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
if ((error = sock_create_kern(PF_INET, type, protocol, &sock)) < 0)
return error;
if (sin != NULL) {
if (type == SOCK_STREAM)
sock->sk->sk_reuse = 1; /* allow address reuse */
error = sock->ops->bind(sock, (struct sockaddr *) sin,
sizeof(*sin));
if (error < 0)
goto bummer;
}
if (protocol == IPPROTO_TCP) {
if ((error = sock->ops->listen(sock, 64)) < 0)
goto bummer;
}
if ((svsk = svc_setup_socket(serv, sock, &error, 1)) != NULL)
return 0;
bummer:
dprintk("svc: svc_create_socket error = %d\n", -error);
sock_release(sock);
return error;
}
/*
* Remove a dead socket
*/
void
svc_delete_socket(struct svc_sock *svsk)
{
struct svc_serv *serv;
struct sock *sk;
dprintk("svc: svc_delete_socket(%p)\n", svsk);
serv = svsk->sk_server;
sk = svsk->sk_sk;
sk->sk_state_change = svsk->sk_ostate;
sk->sk_data_ready = svsk->sk_odata;
sk->sk_write_space = svsk->sk_owspace;
spin_lock_bh(&serv->sv_lock);
list_del_init(&svsk->sk_list);
list_del_init(&svsk->sk_ready);
if (!test_and_set_bit(SK_DEAD, &svsk->sk_flags))
if (test_bit(SK_TEMP, &svsk->sk_flags))
serv->sv_tmpcnt--;
if (!svsk->sk_inuse) {
spin_unlock_bh(&serv->sv_lock);
sock_release(svsk->sk_sock);
kfree(svsk);
} else {
spin_unlock_bh(&serv->sv_lock);
dprintk(KERN_NOTICE "svc: server socket destroy delayed\n");
/* svsk->sk_server = NULL; */
}
}
/*
* Make a socket for nfsd and lockd
*/
int
svc_makesock(struct svc_serv *serv, int protocol, unsigned short port)
{
struct sockaddr_in sin;
dprintk("svc: creating socket proto = %d\n", protocol);
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = INADDR_ANY;
sin.sin_port = htons(port);
return svc_create_socket(serv, protocol, &sin);
}
/*
* Handle defer and revisit of requests
*/
static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
{
struct svc_deferred_req *dr = container_of(dreq, struct svc_deferred_req, handle);
struct svc_serv *serv = dreq->owner;
struct svc_sock *svsk;
if (too_many) {
svc_sock_put(dr->svsk);
kfree(dr);
return;
}
dprintk("revisit queued\n");
svsk = dr->svsk;
dr->svsk = NULL;
spin_lock_bh(&serv->sv_lock);
list_add(&dr->handle.recent, &svsk->sk_deferred);
spin_unlock_bh(&serv->sv_lock);
set_bit(SK_DEFERRED, &svsk->sk_flags);
svc_sock_enqueue(svsk);
svc_sock_put(svsk);
}
static struct cache_deferred_req *
svc_defer(struct cache_req *req)
{
struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
int size = sizeof(struct svc_deferred_req) + (rqstp->rq_arg.len);
struct svc_deferred_req *dr;
if (rqstp->rq_arg.page_len)
return NULL; /* if more than a page, give up FIXME */
if (rqstp->rq_deferred) {
dr = rqstp->rq_deferred;
rqstp->rq_deferred = NULL;
} else {
int skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
/* FIXME maybe discard if size too large */
dr = kmalloc(size, GFP_KERNEL);
if (dr == NULL)
return NULL;
dr->handle.owner = rqstp->rq_server;
dr->prot = rqstp->rq_prot;
dr->addr = rqstp->rq_addr;
dr->daddr = rqstp->rq_daddr;
dr->argslen = rqstp->rq_arg.len >> 2;
memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip, dr->argslen<<2);
}
spin_lock_bh(&rqstp->rq_server->sv_lock);
rqstp->rq_sock->sk_inuse++;
dr->svsk = rqstp->rq_sock;
spin_unlock_bh(&rqstp->rq_server->sv_lock);
dr->handle.revisit = svc_revisit;
return &dr->handle;
}
/*
* recv data from a deferred request into an active one
*/
static int svc_deferred_recv(struct svc_rqst *rqstp)
{
struct svc_deferred_req *dr = rqstp->rq_deferred;
rqstp->rq_arg.head[0].iov_base = dr->args;
rqstp->rq_arg.head[0].iov_len = dr->argslen<<2;
rqstp->rq_arg.page_len = 0;
rqstp->rq_arg.len = dr->argslen<<2;
rqstp->rq_prot = dr->prot;
rqstp->rq_addr = dr->addr;
rqstp->rq_daddr = dr->daddr;
return dr->argslen<<2;
}
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk)
{
struct svc_deferred_req *dr = NULL;
struct svc_serv *serv = svsk->sk_server;
if (!test_bit(SK_DEFERRED, &svsk->sk_flags))
return NULL;
spin_lock_bh(&serv->sv_lock);
clear_bit(SK_DEFERRED, &svsk->sk_flags);
if (!list_empty(&svsk->sk_deferred)) {
dr = list_entry(svsk->sk_deferred.next,
struct svc_deferred_req,
handle.recent);
list_del_init(&dr->handle.recent);
set_bit(SK_DEFERRED, &svsk->sk_flags);
}
spin_unlock_bh(&serv->sv_lock);
return dr;
}
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