WSL2-Linux-Kernel/net/sunrpc/svc_xprt.c

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C
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/*
* linux/net/sunrpc/svc_xprt.c
*
* Author: Tom Tucker <tom@opengridcomputing.com>
*/
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <net/sock.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svc_xprt.h>
#define RPCDBG_FACILITY RPCDBG_SVCXPRT
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
static int svc_deferred_recv(struct svc_rqst *rqstp);
static struct cache_deferred_req *svc_defer(struct cache_req *req);
static void svc_age_temp_xprts(unsigned long closure);
/* apparently the "standard" is that clients close
* idle connections after 5 minutes, servers after
* 6 minutes
* http://www.connectathon.org/talks96/nfstcp.pdf
*/
static int svc_conn_age_period = 6*60;
/* List of registered transport classes */
static DEFINE_SPINLOCK(svc_xprt_class_lock);
static LIST_HEAD(svc_xprt_class_list);
/* SMP locking strategy:
*
* svc_pool->sp_lock protects most of the fields of that pool.
* svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
* when both need to be taken (rare), svc_serv->sv_lock is first.
* BKL protects svc_serv->sv_nrthread.
* svc_sock->sk_lock protects the svc_sock->sk_deferred list
* and the ->sk_info_authunix cache.
*
* The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
* enqueued multiply. During normal transport processing this bit
* is set by svc_xprt_enqueue and cleared by svc_xprt_received.
* Providers should not manipulate this bit directly.
*
* Some flags can be set to certain values at any time
* providing that certain rules are followed:
*
* XPT_CONN, XPT_DATA:
* - Can be set or cleared at any time.
* - After a set, svc_xprt_enqueue must be called to enqueue
* the transport for processing.
* - After a clear, the transport must be read/accepted.
* If this succeeds, it must be set again.
* XPT_CLOSE:
* - Can set at any time. It is never cleared.
* XPT_DEAD:
* - Can only be set while XPT_BUSY is held which ensures
* that no other thread will be using the transport or will
* try to set XPT_DEAD.
*/
int svc_reg_xprt_class(struct svc_xprt_class *xcl)
{
struct svc_xprt_class *cl;
int res = -EEXIST;
dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
INIT_LIST_HEAD(&xcl->xcl_list);
spin_lock(&svc_xprt_class_lock);
/* Make sure there isn't already a class with the same name */
list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
goto out;
}
list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
res = 0;
out:
spin_unlock(&svc_xprt_class_lock);
return res;
}
EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
{
dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name);
spin_lock(&svc_xprt_class_lock);
list_del_init(&xcl->xcl_list);
spin_unlock(&svc_xprt_class_lock);
}
EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
/*
* Format the transport list for printing
*/
int svc_print_xprts(char *buf, int maxlen)
{
struct list_head *le;
char tmpstr[80];
int len = 0;
buf[0] = '\0';
spin_lock(&svc_xprt_class_lock);
list_for_each(le, &svc_xprt_class_list) {
int slen;
struct svc_xprt_class *xcl =
list_entry(le, struct svc_xprt_class, xcl_list);
sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
slen = strlen(tmpstr);
if (len + slen > maxlen)
break;
len += slen;
strcat(buf, tmpstr);
}
spin_unlock(&svc_xprt_class_lock);
return len;
}
static void svc_xprt_free(struct kref *kref)
{
struct svc_xprt *xprt =
container_of(kref, struct svc_xprt, xpt_ref);
struct module *owner = xprt->xpt_class->xcl_owner;
if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)
&& xprt->xpt_auth_cache != NULL)
svcauth_unix_info_release(xprt->xpt_auth_cache);
xprt->xpt_ops->xpo_free(xprt);
module_put(owner);
}
void svc_xprt_put(struct svc_xprt *xprt)
{
kref_put(&xprt->xpt_ref, svc_xprt_free);
}
EXPORT_SYMBOL_GPL(svc_xprt_put);
/*
* Called by transport drivers to initialize the transport independent
* portion of the transport instance.
*/
void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt,
struct svc_serv *serv)
{
memset(xprt, 0, sizeof(*xprt));
xprt->xpt_class = xcl;
xprt->xpt_ops = xcl->xcl_ops;
kref_init(&xprt->xpt_ref);
xprt->xpt_server = serv;
INIT_LIST_HEAD(&xprt->xpt_list);
INIT_LIST_HEAD(&xprt->xpt_ready);
INIT_LIST_HEAD(&xprt->xpt_deferred);
mutex_init(&xprt->xpt_mutex);
spin_lock_init(&xprt->xpt_lock);
set_bit(XPT_BUSY, &xprt->xpt_flags);
}
EXPORT_SYMBOL_GPL(svc_xprt_init);
static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl,
struct svc_serv *serv,
unsigned short port, int flags)
{
struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_ANY),
.sin_port = htons(port),
};
struct sockaddr_in6 sin6 = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ANY_INIT,
.sin6_port = htons(port),
};
struct sockaddr *sap;
size_t len;
switch (serv->sv_family) {
case AF_INET:
sap = (struct sockaddr *)&sin;
len = sizeof(sin);
break;
case AF_INET6:
sap = (struct sockaddr *)&sin6;
len = sizeof(sin6);
break;
default:
return ERR_PTR(-EAFNOSUPPORT);
}
return xcl->xcl_ops->xpo_create(serv, sap, len, flags);
}
int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port,
int flags)
{
struct svc_xprt_class *xcl;
dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
spin_lock(&svc_xprt_class_lock);
list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
struct svc_xprt *newxprt;
if (strcmp(xprt_name, xcl->xcl_name))
continue;
if (!try_module_get(xcl->xcl_owner))
goto err;
spin_unlock(&svc_xprt_class_lock);
newxprt = __svc_xpo_create(xcl, serv, port, flags);
if (IS_ERR(newxprt)) {
module_put(xcl->xcl_owner);
return PTR_ERR(newxprt);
}
clear_bit(XPT_TEMP, &newxprt->xpt_flags);
spin_lock_bh(&serv->sv_lock);
list_add(&newxprt->xpt_list, &serv->sv_permsocks);
spin_unlock_bh(&serv->sv_lock);
clear_bit(XPT_BUSY, &newxprt->xpt_flags);
return svc_xprt_local_port(newxprt);
}
err:
spin_unlock(&svc_xprt_class_lock);
dprintk("svc: transport %s not found\n", xprt_name);
return -ENOENT;
}
EXPORT_SYMBOL_GPL(svc_create_xprt);
svc: Move the sockaddr information to svc_xprt This patch moves the transport sockaddr to the svc_xprt structure. Convenience functions are added to set and get the local and remote addresses of a transport from the transport provider as well as determine the length of a sockaddr. A transport is responsible for setting the xpt_local and xpt_remote addresses in the svc_xprt structure as part of transport creation and xpo_accept processing. This cannot be done in a generic way and in fact varies between TCP, UDP and RDMA. A set of xpo_ functions (e.g. getlocalname, getremotename) could have been added but this would have resulted in additional caching and copying of the addresses around. Note that the xpt_local address should also be set on listening endpoints; for TCP/RDMA this is done as part of endpoint creation. For connected transports like TCP and RDMA, the addresses never change and can be set once and copied into the rqstp structure for each request. For UDP, however, the local and remote addresses may change for each request. In this case, the address information is obtained from the UDP recvmsg info and copied into the rqstp structure from there. A svc_xprt_local_port function was also added that returns the local port given a transport. This is used by svc_create_xprt when returning the port associated with a newly created transport, and later when creating a generic find transport service to check if a service is already listening on a given port. Signed-off-by: Tom Tucker <tom@opengridcomputing.com> Acked-by: Neil Brown <neilb@suse.de> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Greg Banks <gnb@sgi.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2007-12-31 06:08:12 +03:00
/*
* Copy the local and remote xprt addresses to the rqstp structure
*/
void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
{
struct sockaddr *sin;
memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
rqstp->rq_addrlen = xprt->xpt_remotelen;
/*
* Destination address in request is needed for binding the
* source address in RPC replies/callbacks later.
*/
sin = (struct sockaddr *)&xprt->xpt_local;
switch (sin->sa_family) {
case AF_INET:
rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr;
break;
case AF_INET6:
rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr;
break;
}
}
EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
/**
* svc_print_addr - Format rq_addr field for printing
* @rqstp: svc_rqst struct containing address to print
* @buf: target buffer for formatted address
* @len: length of target buffer
*
*/
char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
{
return __svc_print_addr(svc_addr(rqstp), buf, len);
}
EXPORT_SYMBOL_GPL(svc_print_addr);
/*
* Queue up an idle server thread. Must have pool->sp_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 pollute
* the cache.
*/
static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
{
list_add(&rqstp->rq_list, &pool->sp_threads);
}
/*
* Dequeue an nfsd thread. Must have pool->sp_lock held.
*/
static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
{
list_del(&rqstp->rq_list);
}
/*
* Queue up a transport with data pending. If there are idle nfsd
* processes, wake 'em up.
*
*/
void svc_xprt_enqueue(struct svc_xprt *xprt)
{
struct svc_serv *serv = xprt->xpt_server;
struct svc_pool *pool;
struct svc_rqst *rqstp;
int cpu;
if (!(xprt->xpt_flags &
((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED))))
return;
cpu = get_cpu();
pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
put_cpu();
spin_lock_bh(&pool->sp_lock);
if (!list_empty(&pool->sp_threads) &&
!list_empty(&pool->sp_sockets))
printk(KERN_ERR
"svc_xprt_enqueue: "
"threads and transports both waiting??\n");
if (test_bit(XPT_DEAD, &xprt->xpt_flags)) {
/* Don't enqueue dead transports */
dprintk("svc: transport %p is dead, not enqueued\n", xprt);
goto out_unlock;
}
/* Mark transport as busy. It will remain in this state until
* the provider calls svc_xprt_received. We update XPT_BUSY
* atomically because it also guards against trying to enqueue
* the transport twice.
*/
if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
/* Don't enqueue transport while already enqueued */
dprintk("svc: transport %p busy, not enqueued\n", xprt);
goto out_unlock;
}
BUG_ON(xprt->xpt_pool != NULL);
xprt->xpt_pool = pool;
/* Handle pending connection */
if (test_bit(XPT_CONN, &xprt->xpt_flags))
goto process;
/* Handle close in-progress */
if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
goto process;
/* Check if we have space to reply to a request */
if (!xprt->xpt_ops->xpo_has_wspace(xprt)) {
/* Don't enqueue while not enough space for reply */
dprintk("svc: no write space, transport %p not enqueued\n",
xprt);
xprt->xpt_pool = NULL;
clear_bit(XPT_BUSY, &xprt->xpt_flags);
goto out_unlock;
}
process:
if (!list_empty(&pool->sp_threads)) {
rqstp = list_entry(pool->sp_threads.next,
struct svc_rqst,
rq_list);
dprintk("svc: transport %p served by daemon %p\n",
xprt, rqstp);
svc_thread_dequeue(pool, rqstp);
if (rqstp->rq_xprt)
printk(KERN_ERR
"svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
rqstp, rqstp->rq_xprt);
rqstp->rq_xprt = xprt;
svc_xprt_get(xprt);
rqstp->rq_reserved = serv->sv_max_mesg;
atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
BUG_ON(xprt->xpt_pool != pool);
wake_up(&rqstp->rq_wait);
} else {
dprintk("svc: transport %p put into queue\n", xprt);
list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
BUG_ON(xprt->xpt_pool != pool);
}
out_unlock:
spin_unlock_bh(&pool->sp_lock);
}
EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
/*
* Dequeue the first transport. Must be called with the pool->sp_lock held.
*/
static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
{
struct svc_xprt *xprt;
if (list_empty(&pool->sp_sockets))
return NULL;
xprt = list_entry(pool->sp_sockets.next,
struct svc_xprt, xpt_ready);
list_del_init(&xprt->xpt_ready);
dprintk("svc: transport %p dequeued, inuse=%d\n",
xprt, atomic_read(&xprt->xpt_ref.refcount));
return xprt;
}
/*
* svc_xprt_received conditionally queues the transport for processing
* by another thread. The caller must hold the XPT_BUSY bit and must
* not thereafter touch transport data.
*
* Note: XPT_DATA only gets cleared when a read-attempt finds no (or
* insufficient) data.
*/
void svc_xprt_received(struct svc_xprt *xprt)
{
BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
xprt->xpt_pool = NULL;
clear_bit(XPT_BUSY, &xprt->xpt_flags);
svc_xprt_enqueue(xprt);
}
EXPORT_SYMBOL_GPL(svc_xprt_received);
/**
* 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 transport
* 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_xprt *xprt = rqstp->rq_xprt;
atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
rqstp->rq_reserved = space;
svc_xprt_enqueue(xprt);
}
}
EXPORT_SYMBOL_GPL(svc_reserve);
static void svc_xprt_release(struct svc_rqst *rqstp)
{
struct svc_xprt *xprt = rqstp->rq_xprt;
rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
kfree(rqstp->rq_deferred);
rqstp->rq_deferred = NULL;
svc_free_res_pages(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_xprt = NULL;
svc_xprt_put(xprt);
}
/*
* External function to wake up a server waiting for data
* This really only makes sense for services like lockd
* which have exactly one thread anyway.
*/
void svc_wake_up(struct svc_serv *serv)
{
struct svc_rqst *rqstp;
unsigned int i;
struct svc_pool *pool;
for (i = 0; i < serv->sv_nrpools; i++) {
pool = &serv->sv_pools[i];
spin_lock_bh(&pool->sp_lock);
if (!list_empty(&pool->sp_threads)) {
rqstp = list_entry(pool->sp_threads.next,
struct svc_rqst,
rq_list);
dprintk("svc: daemon %p woken up.\n", rqstp);
/*
svc_thread_dequeue(pool, rqstp);
rqstp->rq_xprt = NULL;
*/
wake_up(&rqstp->rq_wait);
}
spin_unlock_bh(&pool->sp_lock);
}
}
EXPORT_SYMBOL_GPL(svc_wake_up);
int svc_port_is_privileged(struct sockaddr *sin)
{
switch (sin->sa_family) {
case AF_INET:
return ntohs(((struct sockaddr_in *)sin)->sin_port)
< PROT_SOCK;
case AF_INET6:
return ntohs(((struct sockaddr_in6 *)sin)->sin6_port)
< PROT_SOCK;
default:
return 0;
}
}
/*
* Make sure that we don't have too many active connections. If we have,
* something must be dropped. It's not clear what will happen if we allow
* "too many" connections, but when dealing with network-facing software,
* we have to code defensively. Here we do that by imposing hard limits.
*
* 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.
*
* single-threaded services that expect a lot of clients will probably
* need to set sv_maxconn to override the default value which is based
* on the number of threads
*/
static void svc_check_conn_limits(struct svc_serv *serv)
{
unsigned int limit = serv->sv_maxconn ? serv->sv_maxconn :
(serv->sv_nrthreads+3) * 20;
if (serv->sv_tmpcnt > limit) {
struct svc_xprt *xprt = 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 "
"connections, consider increasing %s\n",
serv->sv_name, serv->sv_maxconn ?
"the max number of connections." :
"the number of threads.");
}
/*
* Always select the oldest connection. It's not fair,
* but so is life
*/
xprt = list_entry(serv->sv_tempsocks.prev,
struct svc_xprt,
xpt_list);
set_bit(XPT_CLOSE, &xprt->xpt_flags);
svc_xprt_get(xprt);
}
spin_unlock_bh(&serv->sv_lock);
if (xprt) {
svc_xprt_enqueue(xprt);
svc_xprt_put(xprt);
}
}
}
/*
* Receive the next request on any transport. This code is carefully
* organised not to touch any cachelines in the shared svc_serv
* structure, only cachelines in the local svc_pool.
*/
int svc_recv(struct svc_rqst *rqstp, long timeout)
{
struct svc_xprt *xprt = NULL;
struct svc_serv *serv = rqstp->rq_server;
struct svc_pool *pool = rqstp->rq_pool;
int len, i;
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_xprt)
printk(KERN_ERR
"svc_recv: service %p, transport not NULL!\n",
rqstp);
if (waitqueue_active(&rqstp->rq_wait))
printk(KERN_ERR
"svc_recv: service %p, wait queue active!\n",
rqstp);
/* now allocate needed pages. If we get a failure, sleep briefly */
pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
for (i = 0; i < pages ; i++)
while (rqstp->rq_pages[i] == NULL) {
struct page *p = alloc_page(GFP_KERNEL);
if (!p) {
set_current_state(TASK_INTERRUPTIBLE);
if (signalled() || kthread_should_stop()) {
set_current_state(TASK_RUNNING);
return -EINTR;
}
schedule_timeout(msecs_to_jiffies(500));
}
rqstp->rq_pages[i] = p;
}
rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */
BUG_ON(pages >= RPCSVC_MAXPAGES);
/* 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_pages[0]);
arg->head[0].iov_len = PAGE_SIZE;
arg->pages = rqstp->rq_pages + 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() || kthread_should_stop())
return -EINTR;
spin_lock_bh(&pool->sp_lock);
xprt = svc_xprt_dequeue(pool);
if (xprt) {
rqstp->rq_xprt = xprt;
svc_xprt_get(xprt);
rqstp->rq_reserved = serv->sv_max_mesg;
atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
} else {
/* No data pending. Go to sleep */
svc_thread_enqueue(pool, rqstp);
/*
* We have to be able to interrupt this wait
* to bring down the daemons ...
*/
set_current_state(TASK_INTERRUPTIBLE);
/*
* checking kthread_should_stop() here allows us to avoid
* locking and signalling when stopping kthreads that call
* svc_recv. If the thread has already been woken up, then
* we can exit here without sleeping. If not, then it
* it'll be woken up quickly during the schedule_timeout
*/
if (kthread_should_stop()) {
set_current_state(TASK_RUNNING);
spin_unlock_bh(&pool->sp_lock);
return -EINTR;
}
add_wait_queue(&rqstp->rq_wait, &wait);
spin_unlock_bh(&pool->sp_lock);
schedule_timeout(timeout);
try_to_freeze();
spin_lock_bh(&pool->sp_lock);
remove_wait_queue(&rqstp->rq_wait, &wait);
xprt = rqstp->rq_xprt;
if (!xprt) {
svc_thread_dequeue(pool, rqstp);
spin_unlock_bh(&pool->sp_lock);
dprintk("svc: server %p, no data yet\n", rqstp);
if (signalled() || kthread_should_stop())
return -EINTR;
else
return -EAGAIN;
}
}
spin_unlock_bh(&pool->sp_lock);
len = 0;
if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
dprintk("svc_recv: found XPT_CLOSE\n");
svc_delete_xprt(xprt);
} else if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
struct svc_xprt *newxpt;
newxpt = xprt->xpt_ops->xpo_accept(xprt);
if (newxpt) {
/*
* We know this module_get will succeed because the
* listener holds a reference too
*/
__module_get(newxpt->xpt_class->xcl_owner);
svc_check_conn_limits(xprt->xpt_server);
spin_lock_bh(&serv->sv_lock);
set_bit(XPT_TEMP, &newxpt->xpt_flags);
list_add(&newxpt->xpt_list, &serv->sv_tempsocks);
serv->sv_tmpcnt++;
if (serv->sv_temptimer.function == NULL) {
/* setup timer to age temp transports */
setup_timer(&serv->sv_temptimer,
svc_age_temp_xprts,
(unsigned long)serv);
mod_timer(&serv->sv_temptimer,
jiffies + svc_conn_age_period * HZ);
}
spin_unlock_bh(&serv->sv_lock);
svc_xprt_received(newxpt);
}
svc_xprt_received(xprt);
} else {
dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
rqstp, pool->sp_id, xprt,
atomic_read(&xprt->xpt_ref.refcount));
rqstp->rq_deferred = svc_deferred_dequeue(xprt);
if (rqstp->rq_deferred) {
svc_xprt_received(xprt);
len = svc_deferred_recv(rqstp);
} else
len = xprt->xpt_ops->xpo_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_xprt_release(rqstp);
return -EAGAIN;
}
clear_bit(XPT_OLD, &xprt->xpt_flags);
rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp));
rqstp->rq_chandle.defer = svc_defer;
if (serv->sv_stats)
serv->sv_stats->netcnt++;
return len;
}
EXPORT_SYMBOL_GPL(svc_recv);
/*
* Drop request
*/
void svc_drop(struct svc_rqst *rqstp)
{
dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt);
svc_xprt_release(rqstp);
}
EXPORT_SYMBOL_GPL(svc_drop);
/*
* Return reply to client.
*/
int svc_send(struct svc_rqst *rqstp)
{
struct svc_xprt *xprt;
int len;
struct xdr_buf *xb;
xprt = rqstp->rq_xprt;
if (!xprt)
return -EFAULT;
/* release the receive skb before sending the reply */
rqstp->rq_xprt->xpt_ops->xpo_release_rqst(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 mutex to serialize outgoing data. */
mutex_lock(&xprt->xpt_mutex);
if (test_bit(XPT_DEAD, &xprt->xpt_flags))
len = -ENOTCONN;
else
len = xprt->xpt_ops->xpo_sendto(rqstp);
mutex_unlock(&xprt->xpt_mutex);
svc_xprt_release(rqstp);
if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
return 0;
return len;
}
/*
* Timer function to close old temporary transports, using
* a mark-and-sweep algorithm.
*/
static void svc_age_temp_xprts(unsigned long closure)
{
struct svc_serv *serv = (struct svc_serv *)closure;
struct svc_xprt *xprt;
struct list_head *le, *next;
LIST_HEAD(to_be_aged);
dprintk("svc_age_temp_xprts\n");
if (!spin_trylock_bh(&serv->sv_lock)) {
/* busy, try again 1 sec later */
dprintk("svc_age_temp_xprts: busy\n");
mod_timer(&serv->sv_temptimer, jiffies + HZ);
return;
}
list_for_each_safe(le, next, &serv->sv_tempsocks) {
xprt = list_entry(le, struct svc_xprt, xpt_list);
/* First time through, just mark it OLD. Second time
* through, close it. */
if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags))
continue;
if (atomic_read(&xprt->xpt_ref.refcount) > 1
|| test_bit(XPT_BUSY, &xprt->xpt_flags))
continue;
svc_xprt_get(xprt);
list_move(le, &to_be_aged);
set_bit(XPT_CLOSE, &xprt->xpt_flags);
set_bit(XPT_DETACHED, &xprt->xpt_flags);
}
spin_unlock_bh(&serv->sv_lock);
while (!list_empty(&to_be_aged)) {
le = to_be_aged.next;
/* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */
list_del_init(le);
xprt = list_entry(le, struct svc_xprt, xpt_list);
dprintk("queuing xprt %p for closing\n", xprt);
/* a thread will dequeue and close it soon */
svc_xprt_enqueue(xprt);
svc_xprt_put(xprt);
}
mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
}
/*
* Remove a dead transport
*/
void svc_delete_xprt(struct svc_xprt *xprt)
{
struct svc_serv *serv = xprt->xpt_server;
struct svc_deferred_req *dr;
/* Only do this once */
if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
return;
dprintk("svc: svc_delete_xprt(%p)\n", xprt);
xprt->xpt_ops->xpo_detach(xprt);
spin_lock_bh(&serv->sv_lock);
if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags))
list_del_init(&xprt->xpt_list);
/*
* We used to delete the transport from whichever list
* it's sk_xprt.xpt_ready node was on, but we don't actually
* need to. This is because the only time we're called
* while still attached to a queue, the queue itself
* is about to be destroyed (in svc_destroy).
*/
if (test_bit(XPT_TEMP, &xprt->xpt_flags))
serv->sv_tmpcnt--;
for (dr = svc_deferred_dequeue(xprt); dr;
dr = svc_deferred_dequeue(xprt)) {
svc_xprt_put(xprt);
kfree(dr);
}
svc_xprt_put(xprt);
spin_unlock_bh(&serv->sv_lock);
}
void svc_close_xprt(struct svc_xprt *xprt)
{
set_bit(XPT_CLOSE, &xprt->xpt_flags);
if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags))
/* someone else will have to effect the close */
return;
svc_xprt_get(xprt);
svc_delete_xprt(xprt);
clear_bit(XPT_BUSY, &xprt->xpt_flags);
svc_xprt_put(xprt);
}
EXPORT_SYMBOL_GPL(svc_close_xprt);
void svc_close_all(struct list_head *xprt_list)
{
struct svc_xprt *xprt;
struct svc_xprt *tmp;
list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) {
set_bit(XPT_CLOSE, &xprt->xpt_flags);
if (test_bit(XPT_BUSY, &xprt->xpt_flags)) {
/* Waiting to be processed, but no threads left,
* So just remove it from the waiting list
*/
list_del_init(&xprt->xpt_ready);
clear_bit(XPT_BUSY, &xprt->xpt_flags);
}
svc_close_xprt(xprt);
}
}
/*
* 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_xprt *xprt = dr->xprt;
spin_lock(&xprt->xpt_lock);
set_bit(XPT_DEFERRED, &xprt->xpt_flags);
if (too_many || test_bit(XPT_DEAD, &xprt->xpt_flags)) {
spin_unlock(&xprt->xpt_lock);
dprintk("revisit canceled\n");
svc_xprt_put(xprt);
kfree(dr);
return;
}
dprintk("revisit queued\n");
dr->xprt = NULL;
list_add(&dr->handle.recent, &xprt->xpt_deferred);
spin_unlock(&xprt->xpt_lock);
svc_xprt_enqueue(xprt);
svc_xprt_put(xprt);
}
/*
* Save the request off for later processing. The request buffer looks
* like this:
*
* <xprt-header><rpc-header><rpc-pagelist><rpc-tail>
*
* This code can only handle requests that consist of an xprt-header
* and rpc-header.
*/
static struct cache_deferred_req *svc_defer(struct cache_req *req)
{
struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
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 {
size_t skip;
size_t size;
/* FIXME maybe discard if size too large */
size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
dr = kmalloc(size, GFP_KERNEL);
if (dr == NULL)
return NULL;
dr->handle.owner = rqstp->rq_server;
dr->prot = rqstp->rq_prot;
memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
dr->addrlen = rqstp->rq_addrlen;
dr->daddr = rqstp->rq_daddr;
dr->argslen = rqstp->rq_arg.len >> 2;
dr->xprt_hlen = rqstp->rq_xprt_hlen;
/* back up head to the start of the buffer and copy */
skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
dr->argslen << 2);
}
svc_xprt_get(rqstp->rq_xprt);
dr->xprt = rqstp->rq_xprt;
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;
/* setup iov_base past transport header */
rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
/* The iov_len does not include the transport header bytes */
rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
rqstp->rq_arg.page_len = 0;
/* The rq_arg.len includes the transport header bytes */
rqstp->rq_arg.len = dr->argslen<<2;
rqstp->rq_prot = dr->prot;
memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
rqstp->rq_addrlen = dr->addrlen;
/* Save off transport header len in case we get deferred again */
rqstp->rq_xprt_hlen = dr->xprt_hlen;
rqstp->rq_daddr = dr->daddr;
rqstp->rq_respages = rqstp->rq_pages;
return (dr->argslen<<2) - dr->xprt_hlen;
}
static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
{
struct svc_deferred_req *dr = NULL;
if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
return NULL;
spin_lock(&xprt->xpt_lock);
clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
if (!list_empty(&xprt->xpt_deferred)) {
dr = list_entry(xprt->xpt_deferred.next,
struct svc_deferred_req,
handle.recent);
list_del_init(&dr->handle.recent);
set_bit(XPT_DEFERRED, &xprt->xpt_flags);
}
spin_unlock(&xprt->xpt_lock);
return dr;
}
/*
* Return the transport instance pointer for the endpoint accepting
* connections/peer traffic from the specified transport class,
* address family and port.
*
* Specifying 0 for the address family or port is effectively a
* wild-card, and will result in matching the first transport in the
* service's list that has a matching class name.
*/
struct svc_xprt *svc_find_xprt(struct svc_serv *serv, char *xcl_name,
int af, int port)
{
struct svc_xprt *xprt;
struct svc_xprt *found = NULL;
/* Sanity check the args */
if (!serv || !xcl_name)
return found;
spin_lock_bh(&serv->sv_lock);
list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
if (strcmp(xprt->xpt_class->xcl_name, xcl_name))
continue;
if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family)
continue;
if (port && port != svc_xprt_local_port(xprt))
continue;
found = xprt;
svc_xprt_get(xprt);
break;
}
spin_unlock_bh(&serv->sv_lock);
return found;
}
EXPORT_SYMBOL_GPL(svc_find_xprt);
/*
* Format a buffer with a list of the active transports. A zero for
* the buflen parameter disables target buffer overflow checking.
*/
int svc_xprt_names(struct svc_serv *serv, char *buf, int buflen)
{
struct svc_xprt *xprt;
char xprt_str[64];
int totlen = 0;
int len;
/* Sanity check args */
if (!serv)
return 0;
spin_lock_bh(&serv->sv_lock);
list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) {
len = snprintf(xprt_str, sizeof(xprt_str),
"%s %d\n", xprt->xpt_class->xcl_name,
svc_xprt_local_port(xprt));
/* If the string was truncated, replace with error string */
if (len >= sizeof(xprt_str))
strcpy(xprt_str, "name-too-long\n");
/* Don't overflow buffer */
len = strlen(xprt_str);
if (buflen && (len + totlen >= buflen))
break;
strcpy(buf+totlen, xprt_str);
totlen += len;
}
spin_unlock_bh(&serv->sv_lock);
return totlen;
}
EXPORT_SYMBOL_GPL(svc_xprt_names);