atm: add owner of push() callback to atmvcc
The atm is using atmvcc->push(vcc, NULL) callback to notify protocol
that vcc will be closed and protocol must detach from it. This callback
is usually used by protocol to decrement module usage count by module_put(),
but it leaves small window then module is still used after module_put().
Now the owner of push() callback is kept in atmvcc and
module_put(atmvcc->owner) is called after the protocol is detached from vcc.
Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Chas Williams <chas@cmf.nrl.navy.mil>
diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h
index 22ef21c..72db2af 100644
--- a/include/linux/atmdev.h
+++ b/include/linux/atmdev.h
@@ -106,6 +106,7 @@
void *dev_data; /* per-device data */
void *proto_data; /* per-protocol data */
struct k_atm_aal_stats *stats; /* pointer to AAL stats group */
+ struct module *owner; /* owner of ->push function */
/* SVC part --- may move later ------------------------------------- */
short itf; /* interface number */
struct sockaddr_atmsvc local;
diff --git a/net/atm/common.c b/net/atm/common.c
index 0c0ad93..2421664 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -156,6 +156,7 @@
atomic_set(&sk->sk_rmem_alloc, 0);
vcc->push = NULL;
vcc->pop = NULL;
+ vcc->owner = NULL;
vcc->push_oam = NULL;
vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
vcc->atm_options = vcc->aal_options = 0;
@@ -175,6 +176,7 @@
vcc->dev->ops->close(vcc);
if (vcc->push)
vcc->push(vcc, NULL); /* atmarpd has no push */
+ module_put(vcc->owner);
while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
atm_return(vcc, skb->truesize);