[PATCH] PATCH 12/16: NFSD: TCP: Close idle TCP connections

Close idle rpc/tcp sockets

We split the list of sv_allsocks into two, one
of permanent sockets (udp, tcp listener) and one
of temporary sockets (tcp data).

Whenever we complete a successful receive on a temp socket,
it gets pushed to the end of the list.

Whenever a thread wants to do something, it first checks if
the oldest temp socket has not has a receive for 6 mintutes
(should possibly be configurable).  It so, we simulate
a close.

Finally we make sure that threads wake up every few minutes
so that if the server is completely idle, all temp
sockets will get closed.

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 38553d55f902e3f24c10e287afe9b7f9f24f39ad..06a92f835975c086395f71838f7a15e8df27c4c9 100644 (file)
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -195,7 +195,7 @@ nfsd(struct svc_rqst *rqstp)
                 * recvfrom routine.
                 */
                while ((err = svc_recv(serv, rqstp,
-                                      MAX_SCHEDULE_TIMEOUT)) == -EAGAIN)
+                                      5*60*HZ)) == -EAGAIN)
                    ;
                if (err < 0)
                        break;

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 003b89a68852f765179870cf17761c81acde34cc..a7f2bcc327a1edf6b37e97835ff6341ce1f99b8a 100644 (file)
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -36,7 +36,8 @@ struct svc_serv {
        unsigned int            sv_bufsz;       /* datagram buffer size */
        unsigned int            sv_xdrsize;     /* XDR buffer size */
 
-       struct list_head        sv_allsocks;    /* all sockets */
+       struct list_head        sv_permsocks;   /* all permanent sockets */
+       struct list_head        sv_tempsocks;   /* all temporary sockets */
 
        char *                  sv_name;        /* service name */
 };

diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index e4bdc96ab6d8b88a5e3a30313ceaeafd56e9a0f1..b8ca275d5ab591f7d7e4150d54d2d601f9a0ce48 100644 (file)
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -41,6 +41,7 @@ struct svc_sock {
        /* private TCP part */
        int                     sk_reclen;      /* length of record */
        int                     sk_tcplen;      /* current read length */
+       time_t                  sk_lastrecv;    /* time of last received request */
 };
 
 /*

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 1c47cf4ac3c4db58fd88e00ffc5201c8f746844f..6656922011e07823bbe31f2053d0752e93a729b4 100644 (file)
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -42,7 +42,8 @@ svc_create(struct svc_program *prog, unsigned int bufsize, unsigned int xdrsize)
        serv->sv_xdrsize   = xdrsize;
        INIT_LIST_HEAD(&serv->sv_threads);
        INIT_LIST_HEAD(&serv->sv_sockets);
-       INIT_LIST_HEAD(&serv->sv_allsocks);
+       INIT_LIST_HEAD(&serv->sv_tempsocks);
+       INIT_LIST_HEAD(&serv->sv_permsocks);
        spin_lock_init(&serv->sv_lock);
 
        serv->sv_name      = prog->pg_name;
@@ -71,8 +72,14 @@ svc_destroy(struct svc_serv *serv)
        } else
                printk("svc_destroy: no threads for serv=%p!\n", serv);
 
-       while (!list_empty(&serv->sv_allsocks)) {
-               svsk = list_entry(serv->sv_allsocks.next,
+       while (!list_empty(&serv->sv_tempsocks)) {
+               svsk = list_entry(serv->sv_tempsocks.next,
+                                 struct svc_sock,
+                                 sk_list);
+               svc_delete_socket(svsk);
+       }
+       while (!list_empty(&serv->sv_permsocks)) {
+               svsk = list_entry(serv->sv_permsocks.next,
                                  struct svc_sock,
                                  sk_list);
                svc_delete_socket(svsk);

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index cbb060ed28dd6d4565f26104410e8d320d0bb000..35a5fb3e001107fbbe7616966730dec4cd74ef3f 100644 (file)
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -585,7 +585,6 @@ svc_tcp_accept(struct svc_sock *svsk)
         * installed the data_ready callback. 
         */
        set_bit(SK_DATA, &newsvsk->sk_flags);
-       set_bit(SK_TEMP, &newsvsk->sk_flags);
        svc_sock_enqueue(newsvsk);
 
        if (serv->sv_stats)
@@ -781,7 +780,7 @@ svc_tcp_init(struct svc_sock *svsk)
 int
 svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
 {
-       struct svc_sock         *svsk;
+       struct svc_sock         *svsk =NULL;
        int                     len;
        DECLARE_WAITQUEUE(wait, current);
 
@@ -805,7 +804,24 @@ svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
                return -EINTR;
 
        spin_lock_bh(&serv->sv_lock);
-       if ((svsk = svc_sock_dequeue(serv)) != NULL) {
+       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 (CURRENT_TIME - 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++;
        } else {
@@ -844,6 +860,14 @@ svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
                svc_sock_release(rqstp);
                return -EAGAIN;
        }
+       svsk->sk_lastrecv = CURRENT_TIME;
+       if (test_bit(SK_TEMP, &svsk->sk_flags)) {
+               /* push active sockets to end of list */
+               spin_lock_bh(&serv->sv_lock);
+               list_del(&svsk->sk_list);
+               list_add_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_userset = 0;
@@ -921,6 +945,7 @@ svc_setup_socket(struct svc_serv *serv, struct socket *sock,
        svsk->sk_ostate = inet->state_change;
        svsk->sk_odata = inet->data_ready;
        svsk->sk_server = serv;
+       svsk->sk_lastrecv = CURRENT_TIME;
 
        /* Initialize the socket */
        if (sock->type == SOCK_DGRAM)
@@ -940,8 +965,15 @@ if (svsk->sk_sk == NULL)
                return NULL;
        }
 
+
        spin_lock_bh(&serv->sv_lock);
-       list_add(&svsk->sk_list, &serv->sv_allsocks);
+       if (!pmap_register) {
+               set_bit(SK_TEMP, &svsk->sk_flags);
+               list_add(&svsk->sk_list, &serv->sv_tempsocks);
+       } 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",