1 files changed, 35 insertions, 12 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 8047800e9a0c..9bdb463765c7 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -114,11 +114,13 @@ cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
         else
                 sch->lpm = 0;
 
-        stsch (sch->schid, &sch->schib);
-
         CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
                       "subchannel 0.%x.%04x!\n", sch->schid.ssid,
                       sch->schid.sch_no);
+
+        if (cio_update_schib(sch))
+                return -ENODEV;
+
         sprintf(dbf_text, "no%s", dev_name(&sch->dev));
         CIO_TRACE_EVENT(0, dbf_text);
         CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
@@ -316,7 +318,8 @@ cio_cancel (struct subchannel *sch)
         switch (ccode) {
         case 0:         /* success */
                 /* Update information in scsw. */
-                stsch (sch->schid, &sch->schib);
+                if (cio_update_schib(sch))
+                        return -ENODEV;
                 return 0;
         case 1:         /* status pending */
                 return -EBUSY;
@@ -358,6 +361,23 @@ cio_modify (struct subchannel *sch)
 }
 
 /**
+ * cio_update_schib - Perform stsch and update schib if subchannel is valid.
+ * @sch: subchannel on which to perform stsch
+ * Return zero on success, -ENODEV otherwise.
+ */
+int cio_update_schib(struct subchannel *sch)
+{
+        struct schib schib;
+
+        if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
+                return -ENODEV;
+
+        memcpy(&sch->schib, &schib, sizeof(schib));
+        return 0;
+}
+EXPORT_SYMBOL_GPL(cio_update_schib);
+
+/**
  * cio_enable_subchannel - enable a subchannel.
  * @sch: subchannel to be enabled
  * @intparm: interruption parameter to set
@@ -365,7 +385,6 @@ cio_modify (struct subchannel *sch)
 int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 {
         char dbf_txt[15];
-        int ccode;
         int retry;
         int ret;
 
@@ -374,8 +393,7 @@ int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
 
         if (sch_is_pseudo_sch(sch))
                 return -EINVAL;
-        ccode = stsch (sch->schid, &sch->schib);
-        if (ccode)
+        if (cio_update_schib(sch))
                 return -ENODEV;
 
         for (retry = 5, ret = 0; retry > 0; retry--) {
@@ -392,7 +410,10 @@ int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
                          */
                         sch->schib.pmcw.csense = 0;
                 if (ret == 0) {
-                        stsch (sch->schid, &sch->schib);
+                        if (cio_update_schib(sch)) {
+                                ret = -ENODEV;
+                                break;
+                        }
                         if (sch->schib.pmcw.ena)
                                 break;
                 }
@@ -415,7 +436,6 @@ EXPORT_SYMBOL_GPL(cio_enable_subchannel);
 int cio_disable_subchannel(struct subchannel *sch)
 {
         char dbf_txt[15];
-        int ccode;
         int retry;
         int ret;
 
@@ -424,8 +444,7 @@ int cio_disable_subchannel(struct subchannel *sch)
 
         if (sch_is_pseudo_sch(sch))
                 return 0;
-        ccode = stsch (sch->schid, &sch->schib);
-        if (ccode == 3)         /* Not operational. */
+        if (cio_update_schib(sch))
                 return -ENODEV;
 
         if (scsw_actl(&sch->schib.scsw) != 0)
@@ -448,7 +467,10 @@ int cio_disable_subchannel(struct subchannel *sch)
                          */
                         break;
                 if (ret == 0) {
-                        stsch (sch->schid, &sch->schib);
+                        if (cio_update_schib(sch)) {
+                                ret = -ENODEV;
+                                break;
+                        }
                         if (!sch->schib.pmcw.ena)
                                 break;
                 }
@@ -851,7 +873,8 @@ __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
                 cc = msch(schid, schib);
                 if (cc)
                         return (cc==3?-ENODEV:-EBUSY);
-                stsch(schid, schib);
+                if (stsch(schid, schib) || !css_sch_is_valid(schib))
+                        return -ENODEV;
                 if (!schib->pmcw.ena)
                         return 0;
         }