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7b54fe61ff
svc_recv() calls alloc_page(), and if it fails it does a 500ms uninterruptible sleep and then reattempts. There doesn't seem to be any real reason for this to be uninterruptible, so change it to an interruptible sleep. Also check for kthread_stop() and signalled() after setting the task state to avoid races that might lead to sleeping after kthread_stop() wakes up the task. I've done some very basic smoke testing with this, but obviously it's hard to test the actual changes since this all depends on an alloc_page() call failing. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
1078 lines
29 KiB
C
1078 lines
29 KiB
C
/*
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* linux/net/sunrpc/svc_xprt.c
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*
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* Author: Tom Tucker <tom@opengridcomputing.com>
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*/
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/fcntl.h>
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#include <linux/net.h>
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#include <linux/in.h>
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#include <linux/inet.h>
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#include <linux/udp.h>
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#include <linux/tcp.h>
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#include <linux/unistd.h>
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#include <linux/slab.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <linux/file.h>
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#include <linux/freezer.h>
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#include <linux/kthread.h>
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#include <net/sock.h>
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#include <net/checksum.h>
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#include <net/ip.h>
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#include <net/ipv6.h>
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#include <net/tcp_states.h>
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#include <linux/uaccess.h>
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#include <asm/ioctls.h>
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#include <linux/sunrpc/types.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/sunrpc/xdr.h>
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#include <linux/sunrpc/stats.h>
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#include <linux/sunrpc/svc_xprt.h>
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#define RPCDBG_FACILITY RPCDBG_SVCXPRT
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static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt);
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static int svc_deferred_recv(struct svc_rqst *rqstp);
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static struct cache_deferred_req *svc_defer(struct cache_req *req);
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static void svc_age_temp_xprts(unsigned long closure);
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/* apparently the "standard" is that clients close
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* idle connections after 5 minutes, servers after
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* 6 minutes
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* http://www.connectathon.org/talks96/nfstcp.pdf
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*/
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static int svc_conn_age_period = 6*60;
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/* List of registered transport classes */
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static DEFINE_SPINLOCK(svc_xprt_class_lock);
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static LIST_HEAD(svc_xprt_class_list);
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/* SMP locking strategy:
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*
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* svc_pool->sp_lock protects most of the fields of that pool.
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* svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt.
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* when both need to be taken (rare), svc_serv->sv_lock is first.
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* BKL protects svc_serv->sv_nrthread.
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* svc_sock->sk_lock protects the svc_sock->sk_deferred list
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* and the ->sk_info_authunix cache.
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*
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* The XPT_BUSY bit in xprt->xpt_flags prevents a transport being
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* enqueued multiply. During normal transport processing this bit
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* is set by svc_xprt_enqueue and cleared by svc_xprt_received.
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* Providers should not manipulate this bit directly.
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*
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* Some flags can be set to certain values at any time
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* providing that certain rules are followed:
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*
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* XPT_CONN, XPT_DATA:
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* - Can be set or cleared at any time.
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* - After a set, svc_xprt_enqueue must be called to enqueue
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* the transport for processing.
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* - After a clear, the transport must be read/accepted.
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* If this succeeds, it must be set again.
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* XPT_CLOSE:
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* - Can set at any time. It is never cleared.
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* XPT_DEAD:
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* - Can only be set while XPT_BUSY is held which ensures
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* that no other thread will be using the transport or will
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* try to set XPT_DEAD.
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*/
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int svc_reg_xprt_class(struct svc_xprt_class *xcl)
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{
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struct svc_xprt_class *cl;
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int res = -EEXIST;
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dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name);
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INIT_LIST_HEAD(&xcl->xcl_list);
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spin_lock(&svc_xprt_class_lock);
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/* Make sure there isn't already a class with the same name */
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list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) {
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if (strcmp(xcl->xcl_name, cl->xcl_name) == 0)
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goto out;
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}
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list_add_tail(&xcl->xcl_list, &svc_xprt_class_list);
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res = 0;
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out:
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spin_unlock(&svc_xprt_class_lock);
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return res;
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}
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EXPORT_SYMBOL_GPL(svc_reg_xprt_class);
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void svc_unreg_xprt_class(struct svc_xprt_class *xcl)
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{
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dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name);
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spin_lock(&svc_xprt_class_lock);
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list_del_init(&xcl->xcl_list);
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spin_unlock(&svc_xprt_class_lock);
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}
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EXPORT_SYMBOL_GPL(svc_unreg_xprt_class);
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/*
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* Format the transport list for printing
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*/
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int svc_print_xprts(char *buf, int maxlen)
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{
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struct list_head *le;
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char tmpstr[80];
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int len = 0;
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buf[0] = '\0';
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spin_lock(&svc_xprt_class_lock);
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list_for_each(le, &svc_xprt_class_list) {
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int slen;
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struct svc_xprt_class *xcl =
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list_entry(le, struct svc_xprt_class, xcl_list);
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sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload);
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slen = strlen(tmpstr);
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if (len + slen > maxlen)
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break;
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len += slen;
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strcat(buf, tmpstr);
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}
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spin_unlock(&svc_xprt_class_lock);
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return len;
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}
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static void svc_xprt_free(struct kref *kref)
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{
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struct svc_xprt *xprt =
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container_of(kref, struct svc_xprt, xpt_ref);
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struct module *owner = xprt->xpt_class->xcl_owner;
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if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)
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&& xprt->xpt_auth_cache != NULL)
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svcauth_unix_info_release(xprt->xpt_auth_cache);
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xprt->xpt_ops->xpo_free(xprt);
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module_put(owner);
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}
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void svc_xprt_put(struct svc_xprt *xprt)
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{
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kref_put(&xprt->xpt_ref, svc_xprt_free);
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}
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EXPORT_SYMBOL_GPL(svc_xprt_put);
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/*
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* Called by transport drivers to initialize the transport independent
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* portion of the transport instance.
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*/
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void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt,
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struct svc_serv *serv)
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{
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memset(xprt, 0, sizeof(*xprt));
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xprt->xpt_class = xcl;
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xprt->xpt_ops = xcl->xcl_ops;
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kref_init(&xprt->xpt_ref);
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xprt->xpt_server = serv;
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INIT_LIST_HEAD(&xprt->xpt_list);
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INIT_LIST_HEAD(&xprt->xpt_ready);
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INIT_LIST_HEAD(&xprt->xpt_deferred);
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mutex_init(&xprt->xpt_mutex);
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spin_lock_init(&xprt->xpt_lock);
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set_bit(XPT_BUSY, &xprt->xpt_flags);
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}
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EXPORT_SYMBOL_GPL(svc_xprt_init);
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int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port,
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int flags)
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{
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struct svc_xprt_class *xcl;
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struct sockaddr_in sin = {
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.sin_family = AF_INET,
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.sin_addr.s_addr = htonl(INADDR_ANY),
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.sin_port = htons(port),
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};
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dprintk("svc: creating transport %s[%d]\n", xprt_name, port);
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spin_lock(&svc_xprt_class_lock);
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list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) {
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struct svc_xprt *newxprt;
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if (strcmp(xprt_name, xcl->xcl_name))
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continue;
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if (!try_module_get(xcl->xcl_owner))
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goto err;
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spin_unlock(&svc_xprt_class_lock);
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newxprt = xcl->xcl_ops->
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xpo_create(serv, (struct sockaddr *)&sin, sizeof(sin),
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flags);
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if (IS_ERR(newxprt)) {
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module_put(xcl->xcl_owner);
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return PTR_ERR(newxprt);
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}
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clear_bit(XPT_TEMP, &newxprt->xpt_flags);
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spin_lock_bh(&serv->sv_lock);
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list_add(&newxprt->xpt_list, &serv->sv_permsocks);
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spin_unlock_bh(&serv->sv_lock);
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clear_bit(XPT_BUSY, &newxprt->xpt_flags);
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return svc_xprt_local_port(newxprt);
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}
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err:
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spin_unlock(&svc_xprt_class_lock);
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dprintk("svc: transport %s not found\n", xprt_name);
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return -ENOENT;
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}
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EXPORT_SYMBOL_GPL(svc_create_xprt);
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/*
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* Copy the local and remote xprt addresses to the rqstp structure
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*/
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void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt)
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{
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struct sockaddr *sin;
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memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen);
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rqstp->rq_addrlen = xprt->xpt_remotelen;
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/*
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* Destination address in request is needed for binding the
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* source address in RPC replies/callbacks later.
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*/
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sin = (struct sockaddr *)&xprt->xpt_local;
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switch (sin->sa_family) {
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case AF_INET:
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rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr;
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break;
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case AF_INET6:
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rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr;
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break;
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}
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}
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EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs);
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/**
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* svc_print_addr - Format rq_addr field for printing
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* @rqstp: svc_rqst struct containing address to print
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* @buf: target buffer for formatted address
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* @len: length of target buffer
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*
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*/
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char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len)
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{
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return __svc_print_addr(svc_addr(rqstp), buf, len);
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}
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EXPORT_SYMBOL_GPL(svc_print_addr);
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/*
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* Queue up an idle server thread. Must have pool->sp_lock held.
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* Note: this is really a stack rather than a queue, so that we only
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* use as many different threads as we need, and the rest don't pollute
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* the cache.
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*/
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static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp)
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{
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list_add(&rqstp->rq_list, &pool->sp_threads);
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}
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/*
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* Dequeue an nfsd thread. Must have pool->sp_lock held.
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*/
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static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp)
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{
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list_del(&rqstp->rq_list);
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}
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/*
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* Queue up a transport with data pending. If there are idle nfsd
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* processes, wake 'em up.
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*
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*/
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void svc_xprt_enqueue(struct svc_xprt *xprt)
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{
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struct svc_serv *serv = xprt->xpt_server;
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struct svc_pool *pool;
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struct svc_rqst *rqstp;
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int cpu;
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if (!(xprt->xpt_flags &
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((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED))))
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return;
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if (test_bit(XPT_DEAD, &xprt->xpt_flags))
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return;
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cpu = get_cpu();
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pool = svc_pool_for_cpu(xprt->xpt_server, cpu);
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put_cpu();
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spin_lock_bh(&pool->sp_lock);
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if (!list_empty(&pool->sp_threads) &&
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!list_empty(&pool->sp_sockets))
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printk(KERN_ERR
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"svc_xprt_enqueue: "
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"threads and transports both waiting??\n");
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if (test_bit(XPT_DEAD, &xprt->xpt_flags)) {
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/* Don't enqueue dead transports */
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dprintk("svc: transport %p is dead, not enqueued\n", xprt);
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goto out_unlock;
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}
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/* Mark transport as busy. It will remain in this state until
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* the provider calls svc_xprt_received. We update XPT_BUSY
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* atomically because it also guards against trying to enqueue
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* the transport twice.
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*/
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if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) {
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/* Don't enqueue transport while already enqueued */
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dprintk("svc: transport %p busy, not enqueued\n", xprt);
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goto out_unlock;
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}
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BUG_ON(xprt->xpt_pool != NULL);
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xprt->xpt_pool = pool;
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/* Handle pending connection */
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if (test_bit(XPT_CONN, &xprt->xpt_flags))
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goto process;
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/* Handle close in-progress */
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if (test_bit(XPT_CLOSE, &xprt->xpt_flags))
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goto process;
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/* Check if we have space to reply to a request */
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if (!xprt->xpt_ops->xpo_has_wspace(xprt)) {
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/* Don't enqueue while not enough space for reply */
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dprintk("svc: no write space, transport %p not enqueued\n",
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xprt);
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xprt->xpt_pool = NULL;
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clear_bit(XPT_BUSY, &xprt->xpt_flags);
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goto out_unlock;
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}
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process:
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if (!list_empty(&pool->sp_threads)) {
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rqstp = list_entry(pool->sp_threads.next,
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struct svc_rqst,
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rq_list);
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dprintk("svc: transport %p served by daemon %p\n",
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xprt, rqstp);
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svc_thread_dequeue(pool, rqstp);
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if (rqstp->rq_xprt)
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printk(KERN_ERR
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"svc_xprt_enqueue: server %p, rq_xprt=%p!\n",
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rqstp, rqstp->rq_xprt);
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rqstp->rq_xprt = xprt;
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svc_xprt_get(xprt);
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rqstp->rq_reserved = serv->sv_max_mesg;
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atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
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BUG_ON(xprt->xpt_pool != pool);
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wake_up(&rqstp->rq_wait);
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} else {
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dprintk("svc: transport %p put into queue\n", xprt);
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list_add_tail(&xprt->xpt_ready, &pool->sp_sockets);
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BUG_ON(xprt->xpt_pool != pool);
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}
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out_unlock:
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spin_unlock_bh(&pool->sp_lock);
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}
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EXPORT_SYMBOL_GPL(svc_xprt_enqueue);
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/*
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* Dequeue the first transport. Must be called with the pool->sp_lock held.
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*/
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static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool)
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{
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struct svc_xprt *xprt;
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if (list_empty(&pool->sp_sockets))
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return NULL;
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xprt = list_entry(pool->sp_sockets.next,
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struct svc_xprt, xpt_ready);
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list_del_init(&xprt->xpt_ready);
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dprintk("svc: transport %p dequeued, inuse=%d\n",
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xprt, atomic_read(&xprt->xpt_ref.refcount));
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return xprt;
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}
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|
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/*
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* svc_xprt_received conditionally queues the transport for processing
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* by another thread. The caller must hold the XPT_BUSY bit and must
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* not thereafter touch transport data.
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*
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* Note: XPT_DATA only gets cleared when a read-attempt finds no (or
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* insufficient) data.
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*/
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void svc_xprt_received(struct svc_xprt *xprt)
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{
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BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
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xprt->xpt_pool = NULL;
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clear_bit(XPT_BUSY, &xprt->xpt_flags);
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svc_xprt_enqueue(xprt);
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}
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EXPORT_SYMBOL_GPL(svc_xprt_received);
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|
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/**
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* svc_reserve - change the space reserved for the reply to a request.
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* @rqstp: The request in question
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* @space: new max space to reserve
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*
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* Each request reserves some space on the output queue of the transport
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* to make sure the reply fits. This function reduces that reserved
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* space to be the amount of space used already, plus @space.
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*
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*/
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void svc_reserve(struct svc_rqst *rqstp, int space)
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{
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space += rqstp->rq_res.head[0].iov_len;
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|
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if (space < rqstp->rq_reserved) {
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struct svc_xprt *xprt = rqstp->rq_xprt;
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atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved);
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rqstp->rq_reserved = space;
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|
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svc_xprt_enqueue(xprt);
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}
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}
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EXPORT_SYMBOL(svc_reserve);
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|
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static void svc_xprt_release(struct svc_rqst *rqstp)
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{
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struct svc_xprt *xprt = rqstp->rq_xprt;
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|
|
rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp);
|
|
|
|
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(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.
|
|
*
|
|
* 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.
|
|
*/
|
|
static void svc_check_conn_limits(struct svc_serv *serv)
|
|
{
|
|
if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) {
|
|
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 the "
|
|
"number of nfsd threads\n",
|
|
serv->sv_name);
|
|
}
|
|
/*
|
|
* 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(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(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;
|
|
|
|
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_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) {
|
|
BUG_ON(atomic_read(&xprt->xpt_ref.refcount) < 2);
|
|
if (test_bit(XPT_TEMP, &xprt->xpt_flags))
|
|
serv->sv_tmpcnt--;
|
|
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;
|
|
|
|
if (too_many) {
|
|
svc_xprt_put(xprt);
|
|
kfree(dr);
|
|
return;
|
|
}
|
|
dprintk("revisit queued\n");
|
|
dr->xprt = NULL;
|
|
spin_lock(&xprt->xpt_lock);
|
|
list_add(&dr->handle.recent, &xprt->xpt_deferred);
|
|
spin_unlock(&xprt->xpt_lock);
|
|
set_bit(XPT_DEFERRED, &xprt->xpt_flags);
|
|
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>
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*
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* This code can only handle requests that consist of an xprt-header
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* and rpc-header.
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*/
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static struct cache_deferred_req *svc_defer(struct cache_req *req)
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{
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struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
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struct svc_deferred_req *dr;
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if (rqstp->rq_arg.page_len)
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return NULL; /* if more than a page, give up FIXME */
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if (rqstp->rq_deferred) {
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dr = rqstp->rq_deferred;
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rqstp->rq_deferred = NULL;
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} else {
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size_t skip;
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size_t size;
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/* FIXME maybe discard if size too large */
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size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len;
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dr = kmalloc(size, GFP_KERNEL);
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if (dr == NULL)
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return NULL;
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dr->handle.owner = rqstp->rq_server;
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dr->prot = rqstp->rq_prot;
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memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen);
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dr->addrlen = rqstp->rq_addrlen;
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dr->daddr = rqstp->rq_daddr;
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dr->argslen = rqstp->rq_arg.len >> 2;
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dr->xprt_hlen = rqstp->rq_xprt_hlen;
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/* back up head to the start of the buffer and copy */
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skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
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memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip,
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dr->argslen << 2);
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}
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svc_xprt_get(rqstp->rq_xprt);
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dr->xprt = rqstp->rq_xprt;
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dr->handle.revisit = svc_revisit;
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return &dr->handle;
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}
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/*
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* recv data from a deferred request into an active one
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*/
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static int svc_deferred_recv(struct svc_rqst *rqstp)
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{
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struct svc_deferred_req *dr = rqstp->rq_deferred;
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|
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/* setup iov_base past transport header */
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rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2);
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/* The iov_len does not include the transport header bytes */
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rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen;
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rqstp->rq_arg.page_len = 0;
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/* The rq_arg.len includes the transport header bytes */
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rqstp->rq_arg.len = dr->argslen<<2;
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rqstp->rq_prot = dr->prot;
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memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen);
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rqstp->rq_addrlen = dr->addrlen;
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/* Save off transport header len in case we get deferred again */
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rqstp->rq_xprt_hlen = dr->xprt_hlen;
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rqstp->rq_daddr = dr->daddr;
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rqstp->rq_respages = rqstp->rq_pages;
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return (dr->argslen<<2) - dr->xprt_hlen;
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}
|
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|
|
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static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt)
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{
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struct svc_deferred_req *dr = NULL;
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if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags))
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return NULL;
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spin_lock(&xprt->xpt_lock);
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clear_bit(XPT_DEFERRED, &xprt->xpt_flags);
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if (!list_empty(&xprt->xpt_deferred)) {
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|
dr = list_entry(xprt->xpt_deferred.next,
|
|
struct svc_deferred_req,
|
|
handle.recent);
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|
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);
|