pppoatm: fix missing wakeup in pppoatm_send()

Now that we can return zero from pppoatm_send() for reasons *other* than
the queue being full, that means we can't depend on a subsequent call to
pppoatm_pop() waking the queue, and we might leave it stalled
indefinitely.

Use the ->release_cb() callback to wake the queue after the sock is
unlocked.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
index 3dce84af5dbe..9fcda8c85e9a 100644
--- a/net/atm/pppoatm.c
+++ b/net/atm/pppoatm.c
@@ -60,6 +60,7 @@ struct pppoatm_vcc {
         struct atm_vcc  *atmvcc;        /* VCC descriptor */
         void (*old_push)(struct atm_vcc *, struct sk_buff *);
         void (*old_pop)(struct atm_vcc *, struct sk_buff *);
+        void (*old_release_cb)(struct atm_vcc *);
         struct module *old_owner;
                                         /* keep old push/pop for detaching */
         enum pppoatm_encaps encaps;
@@ -108,6 +109,14 @@ static void pppoatm_wakeup_sender(unsigned long arg)
         ppp_output_wakeup((struct ppp_channel *) arg);
 }
 
+static void pppoatm_release_cb(struct atm_vcc *atmvcc)
+{
+        struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+
+        tasklet_schedule(&pvcc->wakeup_tasklet);
+        if (pvcc->old_release_cb)
+                pvcc->old_release_cb(atmvcc);
+}
 /*
  * This gets called every time the ATM card has finished sending our
  * skb.  The ->old_pop will take care up normal atm flow control,
@@ -152,6 +161,7 @@ static void pppoatm_unassign_vcc(struct atm_vcc *atmvcc)
         pvcc = atmvcc_to_pvcc(atmvcc);
         atmvcc->push = pvcc->old_push;
         atmvcc->pop = pvcc->old_pop;
+        atmvcc->release_cb = pvcc->old_release_cb;
         tasklet_kill(&pvcc->wakeup_tasklet);
         ppp_unregister_channel(&pvcc->chan);
         atmvcc->user_back = NULL;
@@ -388,6 +398,7 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
         pvcc->old_push = atmvcc->push;
         pvcc->old_pop = atmvcc->pop;
         pvcc->old_owner = atmvcc->owner;
+        pvcc->old_release_cb = atmvcc->release_cb;
         pvcc->encaps = (enum pppoatm_encaps) be.encaps;
         pvcc->chan.private = pvcc;
         pvcc->chan.ops = &pppoatm_ops;
@@ -403,6 +414,7 @@ static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
         atmvcc->user_back = pvcc;
         atmvcc->push = pppoatm_push;
         atmvcc->pop = pppoatm_pop;
+        atmvcc->release_cb = pppoatm_release_cb;
         __module_get(THIS_MODULE);
         atmvcc->owner = THIS_MODULE;