From da7de31cc50796a53593785d4508b7b7ffa9a9b2 Mon Sep 17 00:00:00 2001 From: Jennifer Hunt Date: Sat, 14 Jul 2007 19:03:00 -0700 Subject: [AF_IUCV]: Improve description of IUCV and AFIUCV configuration options. Signed-off-by: Jennifer Hunt Signed-off-by: Ursula Braun >braunu@de.ibm.com> Acked-by: Frank Pavlic Signed-off-by: David S. Miller --- net/iucv/Kconfig | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net/iucv') diff --git a/net/iucv/Kconfig b/net/iucv/Kconfig index f8fcc3d10327..16ce9cd4f39e 100644 --- a/net/iucv/Kconfig +++ b/net/iucv/Kconfig @@ -1,13 +1,13 @@ config IUCV - tristate "IUCV support (VM only)" + tristate "IUCV support (S390 - z/VM only)" depends on S390 help - Select this option if you want to use inter-user communication under - VM or VIF sockets. If you run on z/VM, say "Y" to enable a fast + Select this option if you want to use inter-user communication + under VM or VIF. If you run on z/VM, say "Y" to enable a fast communication link between VM guests. config AFIUCV - tristate "AF_IUCV support (VM only)" + tristate "AF_IUCV support (S390 - z/VM only)" depends on IUCV help Select this option if you want to use inter-user communication under -- cgit v1.2.3 From 13fdc9a74df0fec70f421c6891e184ed8c3b9088 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Sat, 14 Jul 2007 19:03:41 -0700 Subject: [AF_IUCV]: Avoid deadlock between iucv_path_connect and tasklet. An iucv deadlock may occur, where one CPU is spinning on the iucv_table_lock for iucv_tasklet_fn(), while another CPU is holding the iucv_table_lock for an iucv_path_connect() and is waiting for the first CPU in an smp_call_function. Solution: replace spin_lock in iucv_tasklet_fn by spin_trylock and reschedule tasklet in case of non-granted lock. Signed-off-by: Ursula Braun Acked-by: Frank Pavlic Signed-off-by: David S. Miller --- net/iucv/iucv.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net/iucv') diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c index b7333061016d..ad5150b8dfa9 100644 --- a/net/iucv/iucv.c +++ b/net/iucv/iucv.c @@ -1494,7 +1494,10 @@ static void iucv_tasklet_fn(unsigned long ignored) struct iucv_irq_list *p, *n; /* Serialize tasklet, iucv_path_sever and iucv_path_connect. */ - spin_lock(&iucv_table_lock); + if (!spin_trylock(&iucv_table_lock)) { + tasklet_schedule(&iucv_tasklet); + return; + } iucv_active_cpu = smp_processor_id(); spin_lock_irq(&iucv_queue_lock); -- cgit v1.2.3 From febca281f677a775c61cd0572c2f35e4ead9e7d5 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Sat, 14 Jul 2007 19:04:25 -0700 Subject: [AF_IUCV]: Add lock when updating accept_q The accept_queue of an af_iucv socket will be corrupted, if adding and deleting of entries in this queue occurs at the same time (connect request from one client, while accept call is processed for another client). Solution: add locking when updating accept_q Signed-off-by: Ursula Braun Acked-by: Frank Pavlic Signed-off-by: David S. Miller --- include/net/iucv/af_iucv.h | 1 + net/iucv/af_iucv.c | 16 ++++++++++++++-- 2 files changed, 15 insertions(+), 2 deletions(-) (limited to 'net/iucv') diff --git a/include/net/iucv/af_iucv.h b/include/net/iucv/af_iucv.h index f9bd11be1891..b6c468cd7f5b 100644 --- a/include/net/iucv/af_iucv.h +++ b/include/net/iucv/af_iucv.h @@ -60,6 +60,7 @@ struct iucv_sock { char dst_user_id[8]; char dst_name[8]; struct list_head accept_q; + spinlock_t accept_q_lock; struct sock *parent; struct iucv_path *path; struct sk_buff_head send_skb_q; diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index d9e9ddb8eac5..53ae14c35f70 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -219,6 +219,7 @@ static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio) sock_init_data(sock, sk); INIT_LIST_HEAD(&iucv_sk(sk)->accept_q); + spin_lock_init(&iucv_sk(sk)->accept_q_lock); skb_queue_head_init(&iucv_sk(sk)->send_skb_q); skb_queue_head_init(&iucv_sk(sk)->backlog_skb_q); iucv_sk(sk)->send_tag = 0; @@ -274,15 +275,25 @@ void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk) void iucv_accept_enqueue(struct sock *parent, struct sock *sk) { + unsigned long flags; + struct iucv_sock *par = iucv_sk(parent); + sock_hold(sk); - list_add_tail(&iucv_sk(sk)->accept_q, &iucv_sk(parent)->accept_q); + spin_lock_irqsave(&par->accept_q_lock, flags); + list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q); + spin_unlock_irqrestore(&par->accept_q_lock, flags); iucv_sk(sk)->parent = parent; parent->sk_ack_backlog++; } void iucv_accept_unlink(struct sock *sk) { + unsigned long flags; + struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent); + + spin_lock_irqsave(&par->accept_q_lock, flags); list_del_init(&iucv_sk(sk)->accept_q); + spin_unlock_irqrestore(&par->accept_q_lock, flags); iucv_sk(sk)->parent->sk_ack_backlog--; iucv_sk(sk)->parent = NULL; sock_put(sk); @@ -298,8 +309,8 @@ struct sock *iucv_accept_dequeue(struct sock *parent, struct socket *newsock) lock_sock(sk); if (sk->sk_state == IUCV_CLOSED) { - release_sock(sk); iucv_accept_unlink(sk); + release_sock(sk); continue; } @@ -879,6 +890,7 @@ static int iucv_callback_connreq(struct iucv_path *path, /* Find out if this path belongs to af_iucv. */ read_lock(&iucv_sk_list.lock); iucv = NULL; + sk = NULL; sk_for_each(sk, node, &iucv_sk_list.head) if (sk->sk_state == IUCV_LISTEN && !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) { -- cgit v1.2.3