diff options
author | Tom Tucker <tom@opengridcomputing.com> | 2007-12-30 21:07:46 -0600 |
---|---|---|
committer | J. Bruce Fields <bfields@citi.umich.edu> | 2008-02-01 16:42:11 -0500 |
commit | e1b3157f9710622bad6c7747d3b08ed3d2394cf6 (patch) | |
tree | e03687e0363fdb2307f7e4909a735e8d1331050a /net/sunrpc/svcsock.c | |
parent | d7c9f1ed972b4a468dd24a2457721704dfe9ca70 (diff) | |
download | linux-e1b3157f9710622bad6c7747d3b08ed3d2394cf6.tar.bz2 |
svc: Change sk_inuse to a kref
Change the atomic_t reference count to a kref and move it to the
transport indepenent svc_xprt structure. Change the reference count
wrapper names to be generic.
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>
Diffstat (limited to 'net/sunrpc/svcsock.c')
-rw-r--r-- | net/sunrpc/svcsock.c | 138 |
1 files changed, 63 insertions, 75 deletions
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index e6bb1b0563ec..db589d187170 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -66,8 +66,8 @@ * after a clear, the socket must be read/accepted * if this succeeds, it must be set again. * SK_CLOSE can set at any time. It is never cleared. - * sk_inuse contains a bias of '1' until SK_DEAD is set. - * so when sk_inuse hits zero, we know the socket is dead + * xpt_ref contains a bias of '1' until SK_DEAD is set. + * so when xprt_ref hits zero, we know the transport is dead * and no-one is using it. * SK_DEAD can only be set while SK_BUSY is held which ensures * no other thread will be using the socket or will try to @@ -285,7 +285,7 @@ svc_sock_enqueue(struct svc_sock *svsk) "svc_sock_enqueue: server %p, rq_sock=%p!\n", rqstp, rqstp->rq_sock); rqstp->rq_sock = svsk; - atomic_inc(&svsk->sk_inuse); + svc_xprt_get(&svsk->sk_xprt); rqstp->rq_reserved = serv->sv_max_mesg; atomic_add(rqstp->rq_reserved, &svsk->sk_reserved); BUG_ON(svsk->sk_pool != pool); @@ -316,7 +316,7 @@ svc_sock_dequeue(struct svc_pool *pool) list_del_init(&svsk->sk_ready); dprintk("svc: socket %p dequeued, inuse=%d\n", - svsk->sk_sk, atomic_read(&svsk->sk_inuse)); + svsk->sk_sk, atomic_read(&svsk->sk_xprt.xpt_ref.refcount)); return svsk; } @@ -359,19 +359,6 @@ void svc_reserve(struct svc_rqst *rqstp, int space) } } -/* - * Release a socket after use. - */ -static inline void -svc_sock_put(struct svc_sock *svsk) -{ - if (atomic_dec_and_test(&svsk->sk_inuse)) { - BUG_ON(!test_bit(SK_DEAD, &svsk->sk_flags)); - module_put(svsk->sk_xprt.xpt_class->xcl_owner); - svsk->sk_xprt.xpt_ops->xpo_free(&svsk->sk_xprt); - } -} - static void svc_sock_release(struct svc_rqst *rqstp) { @@ -398,7 +385,7 @@ svc_sock_release(struct svc_rqst *rqstp) svc_reserve(rqstp, 0); rqstp->rq_sock = NULL; - svc_sock_put(svsk); + svc_xprt_put(&svsk->sk_xprt); } /* @@ -1128,50 +1115,6 @@ failed: } /* - * Make sure that we don't have too many active connections. If we - * have, something must be dropped. - * - * There's no point in trying to do random drop here for DoS - * prevention. The NFS clients does 1 reconnect in 15 seconds. An - * attacker can easily beat that. - * - * The only somewhat efficient mechanism would be if drop old - * connections from the same IP first. But right now we don't even - * record the client IP in svc_sock. - */ -static void svc_check_conn_limits(struct svc_serv *serv) -{ - if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) { - struct svc_sock *svsk = NULL; - spin_lock_bh(&serv->sv_lock); - if (!list_empty(&serv->sv_tempsocks)) { - if (net_ratelimit()) { - /* Try to help the admin */ - printk(KERN_NOTICE "%s: too many open TCP " - "sockets, consider increasing the " - "number of nfsd threads\n", - serv->sv_name); - } - /* - * Always select the oldest socket. It's not fair, - * but so is life - */ - svsk = list_entry(serv->sv_tempsocks.prev, - struct svc_sock, - sk_list); - set_bit(SK_CLOSE, &svsk->sk_flags); - atomic_inc(&svsk->sk_inuse); - } - spin_unlock_bh(&serv->sv_lock); - - if (svsk) { - svc_sock_enqueue(svsk); - svc_sock_put(svsk); - } - } -} - -/* * Receive data from a TCP socket. */ static int @@ -1497,6 +1440,50 @@ svc_sock_update_bufs(struct svc_serv *serv) } /* + * 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_sock *svsk = NULL; + spin_lock_bh(&serv->sv_lock); + if (!list_empty(&serv->sv_tempsocks)) { + if (net_ratelimit()) { + /* Try to help the admin */ + printk(KERN_NOTICE "%s: too many open TCP " + "sockets, consider increasing the " + "number of nfsd threads\n", + serv->sv_name); + } + /* + * Always select the oldest socket. It's not fair, + * but so is life + */ + svsk = list_entry(serv->sv_tempsocks.prev, + struct svc_sock, + sk_list); + set_bit(SK_CLOSE, &svsk->sk_flags); + svc_xprt_get(&svsk->sk_xprt); + } + spin_unlock_bh(&serv->sv_lock); + + if (svsk) { + svc_sock_enqueue(svsk); + svc_xprt_put(&svsk->sk_xprt); + } + } +} + +/* * Receive the next request on any socket. This code is carefully * organised not to touch any cachelines in the shared svc_serv * structure, only cachelines in the local svc_pool. @@ -1556,7 +1543,7 @@ svc_recv(struct svc_rqst *rqstp, long timeout) spin_lock_bh(&pool->sp_lock); if ((svsk = svc_sock_dequeue(pool)) != NULL) { rqstp->rq_sock = svsk; - atomic_inc(&svsk->sk_inuse); + svc_xprt_get(&svsk->sk_xprt); rqstp->rq_reserved = serv->sv_max_mesg; atomic_add(rqstp->rq_reserved, &svsk->sk_reserved); } else { @@ -1605,7 +1592,8 @@ svc_recv(struct svc_rqst *rqstp, long timeout) svc_sock_received(svsk); } else { dprintk("svc: server %p, pool %u, socket %p, inuse=%d\n", - rqstp, pool->sp_id, svsk, atomic_read(&svsk->sk_inuse)); + rqstp, pool->sp_id, svsk, + atomic_read(&svsk->sk_xprt.xpt_ref.refcount)); len = svsk->sk_xprt.xpt_ops->xpo_recvfrom(rqstp); dprintk("svc: got len=%d\n", len); } @@ -1702,9 +1690,10 @@ svc_age_temp_sockets(unsigned long closure) if (!test_and_set_bit(SK_OLD, &svsk->sk_flags)) continue; - if (atomic_read(&svsk->sk_inuse) > 1 || test_bit(SK_BUSY, &svsk->sk_flags)) + if (atomic_read(&svsk->sk_xprt.xpt_ref.refcount) > 1 + || test_bit(SK_BUSY, &svsk->sk_flags)) continue; - atomic_inc(&svsk->sk_inuse); + svc_xprt_get(&svsk->sk_xprt); list_move(le, &to_be_aged); set_bit(SK_CLOSE, &svsk->sk_flags); set_bit(SK_DETACHED, &svsk->sk_flags); @@ -1722,7 +1711,7 @@ svc_age_temp_sockets(unsigned long closure) /* a thread will dequeue and close it soon */ svc_sock_enqueue(svsk); - svc_sock_put(svsk); + svc_xprt_put(&svsk->sk_xprt); } mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); @@ -1767,7 +1756,6 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv, svsk->sk_odata = inet->sk_data_ready; svsk->sk_owspace = inet->sk_write_space; svsk->sk_server = serv; - atomic_set(&svsk->sk_inuse, 1); svsk->sk_lastrecv = get_seconds(); spin_lock_init(&svsk->sk_lock); INIT_LIST_HEAD(&svsk->sk_deferred); @@ -1953,10 +1941,10 @@ svc_delete_socket(struct svc_sock *svsk) * is about to be destroyed (in svc_destroy). */ if (!test_and_set_bit(SK_DEAD, &svsk->sk_flags)) { - BUG_ON(atomic_read(&svsk->sk_inuse)<2); - atomic_dec(&svsk->sk_inuse); + BUG_ON(atomic_read(&svsk->sk_xprt.xpt_ref.refcount) < 2); if (test_bit(SK_TEMP, &svsk->sk_flags)) serv->sv_tmpcnt--; + svc_xprt_put(&svsk->sk_xprt); } spin_unlock_bh(&serv->sv_lock); @@ -1969,10 +1957,10 @@ static void svc_close_socket(struct svc_sock *svsk) /* someone else will have to effect the close */ return; - atomic_inc(&svsk->sk_inuse); + svc_xprt_get(&svsk->sk_xprt); svc_delete_socket(svsk); clear_bit(SK_BUSY, &svsk->sk_flags); - svc_sock_put(svsk); + svc_xprt_put(&svsk->sk_xprt); } void svc_force_close_socket(struct svc_sock *svsk) @@ -1998,7 +1986,7 @@ static void svc_revisit(struct cache_deferred_req *dreq, int too_many) struct svc_sock *svsk; if (too_many) { - svc_sock_put(dr->svsk); + svc_xprt_put(&dr->svsk->sk_xprt); kfree(dr); return; } @@ -2010,7 +1998,7 @@ static void svc_revisit(struct cache_deferred_req *dreq, int too_many) spin_unlock(&svsk->sk_lock); set_bit(SK_DEFERRED, &svsk->sk_flags); svc_sock_enqueue(svsk); - svc_sock_put(svsk); + svc_xprt_put(&svsk->sk_xprt); } static struct cache_deferred_req * @@ -2040,7 +2028,7 @@ svc_defer(struct cache_req *req) dr->argslen = rqstp->rq_arg.len >> 2; memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip, dr->argslen<<2); } - atomic_inc(&rqstp->rq_sock->sk_inuse); + svc_xprt_get(rqstp->rq_xprt); dr->svsk = rqstp->rq_sock; dr->handle.revisit = svc_revisit; |