fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / arch / ia64 / sn / kernel / xpc_main.c

diff --git a/arch/ia64/sn/kernel/xpc_main.c b/arch/ia64/sn/kernel/xpc_main.c
index c28894e..f5be2dc 100644 (file)
--- a/arch/ia64/sn/kernel/xpc_main.c
+++ b/arch/ia64/sn/kernel/xpc_main.c
@@ -52,7 +52,6 @@
 #include <linux/syscalls.h>
 #include <linux/cache.h>
 #include <linux/interrupt.h>
-#include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/reboot.h>
 #include <linux/completion.h>
@@ -226,7 +225,7 @@ xpc_timeout_partition_disengage_request(unsigned long data)
  * Notify the heartbeat check thread that an IRQ has been received.
  */
 static irqreturn_t
-xpc_act_IRQ_handler(int irq, void *dev_id, struct pt_regs *regs)
+xpc_act_IRQ_handler(int irq, void *dev_id)
 {
        atomic_inc(&xpc_act_IRQ_rcvd);
        wake_up_interruptible(&xpc_act_IRQ_wq);
@@ -484,7 +483,7 @@ xpc_activating(void *__partid)
        partid_t partid = (u64) __partid;
        struct xpc_partition *part = &xpc_partitions[partid];
        unsigned long irq_flags;
-       struct sched_param param = { sched_priority: MAX_RT_PRIO - 1 };
+       struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
        int ret;
 
 
@@ -611,12 +610,9 @@ xpc_activate_partition(struct xpc_partition *part)
  *     irq - Interrupt ReQuest number. NOT USED.
  *
  *     dev_id - partid of IPI's potential sender.
- *
- *     regs - processor's context before the processor entered
- *            interrupt code. NOT USED.
  */
 irqreturn_t
-xpc_notify_IRQ_handler(int irq, void *dev_id, struct pt_regs *regs)
+xpc_notify_IRQ_handler(int irq, void *dev_id)
 {
        partid_t partid = (partid_t) (u64) dev_id;
        struct xpc_partition *part = &xpc_partitions[partid];
@@ -688,7 +684,7 @@ xpc_activate_kthreads(struct xpc_channel *ch, int needed)
        dev_dbg(xpc_chan, "create %d new kthreads, partid=%d, channel=%d\n",
                needed, ch->partid, ch->number);
 
-       xpc_create_kthreads(ch, needed);
+       xpc_create_kthreads(ch, needed, 0);
 }
 
 
@@ -782,26 +778,28 @@ xpc_daemonize_kthread(void *args)
                xpc_kthread_waitmsgs(part, ch);
        }
 
-       if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
-               spin_lock_irqsave(&ch->lock, irq_flags);
-               if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
-                               !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
-                       ch->flags |= XPC_C_DISCONNECTINGCALLOUT;
-                       spin_unlock_irqrestore(&ch->lock, irq_flags);
-
-                       xpc_disconnect_callout(ch, xpcDisconnecting);
+       /* let registerer know that connection is disconnecting */
 
-                       spin_lock_irqsave(&ch->lock, irq_flags);
-                       ch->flags |= XPC_C_DISCONNECTINGCALLOUT_MADE;
-               }
+       spin_lock_irqsave(&ch->lock, irq_flags);
+       if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) &&
+                       !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) {
+               ch->flags |= XPC_C_DISCONNECTINGCALLOUT;
                spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+               xpc_disconnect_callout(ch, xpcDisconnecting);
+
+               spin_lock_irqsave(&ch->lock, irq_flags);
+               ch->flags |= XPC_C_DISCONNECTINGCALLOUT_MADE;
+       }
+       spin_unlock_irqrestore(&ch->lock, irq_flags);
+
+       if (atomic_dec_return(&ch->kthreads_assigned) == 0) {
                if (atomic_dec_return(&part->nchannels_engaged) == 0) {
                        xpc_mark_partition_disengaged(part);
                        xpc_IPI_send_disengage(part);
                }
        }
 
-
        xpc_msgqueue_deref(ch);
 
        dev_dbg(xpc_chan, "kthread exiting, partid=%d, channel=%d\n",
@@ -825,7 +823,8 @@ xpc_daemonize_kthread(void *args)
  * partition.
  */
 void
-xpc_create_kthreads(struct xpc_channel *ch, int needed)
+xpc_create_kthreads(struct xpc_channel *ch, int needed,
+                       int ignore_disconnecting)
 {
        unsigned long irq_flags;
        pid_t pid;
@@ -840,16 +839,38 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed)
                 * kthread. That kthread is responsible for doing the
                 * counterpart to the following before it exits.
                 */
+               if (ignore_disconnecting) {
+                       if (!atomic_inc_not_zero(&ch->kthreads_assigned)) {
+                               /* kthreads assigned had gone to zero */
+                               BUG_ON(!(ch->flags &
+                                       XPC_C_DISCONNECTINGCALLOUT_MADE));
+                               break;
+                       }
+
+               } else if (ch->flags & XPC_C_DISCONNECTING) {
+                       break;
+
+               } else if (atomic_inc_return(&ch->kthreads_assigned) == 1) {
+                       if (atomic_inc_return(&part->nchannels_engaged) == 1)
+                               xpc_mark_partition_engaged(part);
+               }
                (void) xpc_part_ref(part);
                xpc_msgqueue_ref(ch);
-               if (atomic_inc_return(&ch->kthreads_assigned) == 1 &&
-                   atomic_inc_return(&part->nchannels_engaged) == 1) {
-                       xpc_mark_partition_engaged(part);
-               }
 
                pid = kernel_thread(xpc_daemonize_kthread, (void *) args, 0);
                if (pid < 0) {
                        /* the fork failed */
+
+                       /*
+                        * NOTE: if (ignore_disconnecting &&
+                        * !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) is true,
+                        * then we'll deadlock if all other kthreads assigned
+                        * to this channel are blocked in the channel's
+                        * registerer, because the only thing that will unblock
+                        * them is the xpcDisconnecting callout that this
+                        * failed kernel_thread would have made.
+                        */
+
                        if (atomic_dec_return(&ch->kthreads_assigned) == 0 &&
                            atomic_dec_return(&part->nchannels_engaged) == 0) {
                                xpc_mark_partition_disengaged(part);
@@ -864,9 +885,6 @@ xpc_create_kthreads(struct xpc_channel *ch, int needed)
                                 * Flag this as an error only if we have an
                                 * insufficient #of kthreads for the channel
                                 * to function.
-                                *
-                                * No xpc_msgqueue_ref() is needed here since
-                                * the channel mgr is doing this.
                                 */
                                spin_lock_irqsave(&ch->lock, irq_flags);
                                XPC_DISCONNECT_CHANNEL(ch, xpcLackOfResources,