Files
bpfire/src/patches/suse-2.6.27.25/patches.arch/s390-08-03-iucv-cpu-hotremove.diff
2009-08-05 10:39:24 +02:00

84 lines
2.5 KiB
Diff

From: Gerald Schaefer <geraldsc@de.ibm.com>
Subject: iucv: failing cpu hot remove for inactive iucv
References: bnc#466462,LTC#51104
Symptom: cpu hot remove rejected with NOTIFY_BAD
Problem: If the iucv module is compiled in / loaded but no user
is registered, cpu hot remove doesn't work. The iucv
cpu hotplug notifier on CPU_DOWN_PREPARE checks, if
the iucv_buffer_cpumask would be empty after the
corresponding bit would be cleared. However the bit
was never set since iucv wasn't enabled. That causes
all cpu hot unplug operations to fail in this scenario.
Solution: Use iucv_path_table as an indicator whether iucv is
enabled or not.
Acked-by: John Jolly <jjolly@suse.de>
---
net/iucv/iucv.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
Index: linux-sles11/net/iucv/iucv.c
===================================================================
--- linux-sles11.orig/net/iucv/iucv.c
+++ linux-sles11/net/iucv/iucv.c
@@ -516,6 +516,7 @@ static int iucv_enable(void)
size_t alloc_size;
int cpu, rc;
+ get_online_cpus();
rc = -ENOMEM;
alloc_size = iucv_max_pathid * sizeof(struct iucv_path);
iucv_path_table = kzalloc(alloc_size, GFP_KERNEL);
@@ -523,19 +524,17 @@ static int iucv_enable(void)
goto out;
/* Declare per cpu buffers. */
rc = -EIO;
- get_online_cpus();
for_each_online_cpu(cpu)
smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);
if (cpus_empty(iucv_buffer_cpumask))
/* No cpu could declare an iucv buffer. */
- goto out_path;
+ goto out;
put_online_cpus();
return 0;
-
-out_path:
- put_online_cpus();
- kfree(iucv_path_table);
out:
+ kfree(iucv_path_table);
+ iucv_path_table = NULL;
+ put_online_cpus();
return rc;
}
@@ -550,8 +549,9 @@ static void iucv_disable(void)
{
get_online_cpus();
on_each_cpu(iucv_retrieve_cpu, NULL, 1);
- put_online_cpus();
kfree(iucv_path_table);
+ iucv_path_table = NULL;
+ put_online_cpus();
}
static int __cpuinit iucv_cpu_notify(struct notifier_block *self,
@@ -588,10 +588,14 @@ static int __cpuinit iucv_cpu_notify(str
case CPU_ONLINE_FROZEN:
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
+ if (!iucv_path_table)
+ break;
smp_call_function_single(cpu, iucv_declare_cpu, NULL, 1);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
+ if (!iucv_path_table)
+ break;
cpumask = iucv_buffer_cpumask;
cpu_clear(cpu, cpumask);
if (cpus_empty(cpumask))