[S390] cio: Fix race for "fast" path gone/path back situations.
Make sure we wait for previous evaluations triggered by path state
changes to have settled before we manipulate path states again.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 007aaeb..b6a40c2 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -217,6 +217,8 @@
if (chp_get_status(chpid) <= 0)
return;
+ /* Wait until previous actions have settled. */
+ css_wait_for_slow_path();
for_each_subchannel_staged(s390_subchannel_remove_chpid, NULL, &chpid);
}
@@ -303,7 +305,8 @@
sprintf(dbf_txt, "fla%x", res_data->fla);
CIO_TRACE_EVENT( 2, dbf_txt);
}
-
+ /* Wait until previous actions have settled. */
+ css_wait_for_slow_path();
/*
* I/O resources may have become accessible.
* Scan through all subchannels that may be concerned and
@@ -561,9 +564,12 @@
sprintf(dbf_txt, "cadd%x.%02x", chpid.cssid, chpid.id);
CIO_TRACE_EVENT(2, dbf_txt);
- if (chp_get_status(chpid) != 0)
+ if (chp_get_status(chpid) != 0) {
+ /* Wait until previous actions have settled. */
+ css_wait_for_slow_path();
for_each_subchannel_staged(__chp_add, __chp_add_new_sch,
&chpid);
+ }
}
static void __s390_subchannel_vary_chpid(struct subchannel *sch,
@@ -650,6 +656,8 @@
*/
int chsc_chp_vary(struct chp_id chpid, int on)
{
+ /* Wait until previous actions have settled. */
+ css_wait_for_slow_path();
/*
* Redo PathVerification on the devices the chpid connects to
*/
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 3b45bbe..3e829c8 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -533,6 +533,12 @@
spin_unlock_irqrestore(&slow_subchannel_lock, flags);
}
+void css_wait_for_slow_path(void)
+{
+ flush_workqueue(ccw_device_notify_work);
+ flush_workqueue(slow_path_wq);
+}
+
/* Reprobe subchannel if unregistered. */
static int reprobe_subchannel(struct subchannel_id schid, void *data)
{
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index b705545..e191351 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -144,6 +144,7 @@
int css_sch_is_valid(struct schib *);
extern struct workqueue_struct *slow_path_wq;
+void css_wait_for_slow_path(void);
extern struct attribute_group *subch_attr_groups[];
#endif